The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,...The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.展开更多
Owing to the inherent limitation of the internal pulse ionization chamber within the AlphaGUARD PQ2000 radon monitor,that is,its inability to discriminate the energy levels of α particles,the ingress of^(220)Rn from ...Owing to the inherent limitation of the internal pulse ionization chamber within the AlphaGUARD PQ2000 radon monitor,that is,its inability to discriminate the energy levels of α particles,the ingress of^(220)Rn from the surrounding environment,along with its decay progeny,poses a substantive challenge in accurately determining the^(222)Rn concentration in the measurement outcomes.Among these,the protracted influence primarily stems from the two enduring decay progenies,namely^(212)Pb with a half-life of 10.64 h and^(212)Bi with a half-life of 60.54 min.This study explored the influence of^(220)Rn progeny on the measurement results of an AlphaGUARD PQ2000 radon monitor by developing a theoretical calculation model.The response coefficient related to the residual^(220)Rn progeny within the AlphaGUARD PQ2000 radon monitor was experimentally validated.In addition,this study investigated the effects of temperature and wind speed on the sensitivity of the instrument to^(220)Rn gas.The research findings revealed commendable agreement between the experimentally measured response coefficients of the residual^(220)Rn progeny and the corresponding values derived from the theoretical model.Notably,both the response coefficients of the AlphaGUARD PQ2000 radon monitor to^(220)Rn gas and its internal residual^(220)Rn progeny increased with elevated temperatures and increased wind speeds,providing a reference for correcting the impact of^(220)Rn and its progeny on the measurement results of^(222)Rn concentration obtained using the AlphaGUARD PQ2000 radon monitor.展开更多
In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy respon...In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy response)of engineered polycarbonate films irradiated with an electron beam(0–600 kGy)were investigated using photoluminescence spectroscopy.The results show a linear relationship between photoluminescence intensity and radiation dose when the thickness of the polycarbonate film is 0.3 mm.A higher fluorescence intensity can be obtained by preheating at 60℃ for 180 min before photoluminescence spectrum analysis.As the temperature during spectral testing and the ambient humidity(during and after irradiation)increased,the photoluminescence intensity of the polycarbonate films decreased.The photoluminescence intensity deviation of the polycarbonate films produced within the same batch at 100 kGy is 2.73%.After ten times of repeated excitations and readouts,the coefficients of variation in photoluminescence intensity are less than 8.6%,and the linear correlation coefficient between photoluminescence intensity and irradiation dose is 0.965 in the dose capture range of 20–600 kGy.Within 60 days of irradiation,the photoluminescence intensity of the polycarbonate film decreased to 60%of the initial value.The response of the 0.3 mm polycarbonate films to electron beams with energies exceeding 3.5 MeV does not differ significantly.This comprehensive analysis indicates the potential of polycarbonate films as a high-radiation dose detection material.展开更多
Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract in...Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.展开更多
Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable.In this study,this effectiveness was ...Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable.In this study,this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains,Shaanxi Province,China.The network of reserves was established mainly for the conservation of the giant panda,a species considered as a surrogate for the conservation of many other endangered species in the region.The habitat suitability of nine protected species,including the giant panda,was modeled by using Maximum Entropy(MAXENT)and their spatial congruence was analyzed.Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones(i.e.,core,buffer and experimental zones).Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species,and giant panda reserves protect a relatively high proportion of the habitat of other protected species.Therefore,giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region.However,a large area of suitable habitat was excluded from the nature reserve network.In addition,four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves.It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones,thus,is being affected by human activities.To increase their conservation effectiveness,nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species.The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.展开更多
Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the represe...Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the representative strain of B. afzelii in China, was analyzed by SDS-PAGE, electro transfer and irnmunoblotting assays. The molecular weights of the protein bands of FP1 were analyzed by Gel-Pro analysis software. In a study using 451 serum samples （159 patients with Lyme disease and 292 controls）, all observed bands were recorded. The accuracy of the WB as a diagnostic test was established by using the ROC curve and Youden index. Results Criteria for a positive diagnosis of Lyme disease were established as at least one band of P83/100, P58, P39, OspB, OspA, P30, P28, OspC, P17, and P14 in the IgG test and at least one band of P83/100, P58, P39, OspA, P30, P28, OspC, P17, and P41 in the IgM test. For IgG criteria, the sensitivity, specificity and Youden index were 69.8%, 98.3%, and 0.681, respectively; for IgM criteria, the sensitivity, specificity and Youden index were 47%, 94.2%, and 0.412, respectively.展开更多
Purpose:This study aimed to investigate the current status of self-differentiation and professional adaptability among undergraduate nursing students,to analyze the relationship between these two variables,and to prov...Purpose:This study aimed to investigate the current status of self-differentiation and professional adaptability among undergraduate nursing students,to analyze the relationship between these two variables,and to provide recommendations for nursing educators.Methods:A total of 341 nursing undergraduate students at the University of South China were investigated using the Differentiation of Self Inventory and the Professional Adaptability Scale for college students.Results:The mean scores of self-differentiation and professional adaptability were 3.70±0.60 and 2.87±0.37,respectively,and the two variables were positively correlated(P<0.01).Conclusion:The level of self-differentiation of undergraduate nursing studentsaffects their professional adaptability.Nursing educators should consider the characteristics of self-differentiation of undergraduate nursing students in developing measures to improve their professional adaptability.展开更多
BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully repre...BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully representative of patients outside Wuhan.Therefore,it is highly essential to analyze the epidemiological and clinical characteristics of COVID-19 in areas outside Wuhan or Hubei Province.To date,a limited number of studies have concentrated on the epidemiological and clinical characteristics of COVID-19 patients with different genders,clinical classification,and with or without basic diseases.AIM To study the epidemiological and clinical characteristics of COVID-19 patients in Hengyang(China)and provide a reliable reference for the prevention and control of COVID-19.METHODS From January 16 to March 2,2020,a total of 48 confirmed cases of COVID-19 were reported in Hengyang,and those cases were included in this study.The diagnostic criteria,clinical classification,and discharge standard related to COVID-19 were in line with the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7)released by National Health Commission and National Administration of Traditional Chinese Medicine.The presence of SARS-CoV-2 in pharyngeal swab specimens was detected by quantitative reverse transcription polymerase chain reaction.All the data were imported into the excel worksheet and statistically analyzed by using SPSS 25.0 software.RESULTS A total of 48 cases of COVID-19 were collected,of which 1 was mild,38 were moderate,and 9 were severe.It was unveiled that there were 31(64.6%)male patients and 17(35.4%)female patients,with a female-to-male ratio of 1.82:1.The range of age of patients with COVID-19 was dominantly 30-49 years old[25(52.1%)of 48],followed by those aged over 60 years old[11(22.9%)].Besides,29.2%(14 of 48)of patients had basic diseases,and 57.2%(8 of 14)of patients with basic diseases were aged over 60 years old.The occupations of 48 COVID-19 patients were mainly farmers working in agricultural production[15(31.5%)of 48],rural migrant workers from Hengyang to Wuhan[15(31.5%)],and service workers operating in the service sector[8(16.7%)].The mean latent period was 6.86±3.57 d,and the median was 7[interquartile range(IQR):4-9]d.The mean time from onset of symptoms to the first physician visit was 3.38±2.98(95%CI:2.58-9.18)d,with a median of 2(IQR:1-5)d,and the mean time from hospital admission to confirmed diagnosis was 2.29±2.11(95%CI:1.18-6.42)d,with a median of 2(IQR:1-3)d.The main symptoms were fever[43(89.6%)of 48],cough and expectoration[41(85.4%)],fatigue[22(45.8%)],and chills[22(45.8%)].Other symptoms included poor appetite[13(27.1%)],sore throat[9(18.8%)],dyspnea[9(18.8%)],diarrhea[7(14.6%)],dizziness[5(10.4%)],headache[5(10.4%)],muscle pain[5(10.4%)],nausea and vomiting[4(8.3%)],hemoptysis[4(8.3%)],and runny nose[1(2.1%)].The numbers of peripheral blood leukocytes,lymphocytes,and eosinophils were significantly reduced in the majority of the patients.The levels of C-reactive protein,fibrinogen,blood glucose,lactate dehydrogenase,Ddimer,alanine aminotransferase(ALT),aspartate aminotransferase(AST),gamma-glutamyl transferase(γ-GT),myoglobin(MB),and creatine kinase(CK)were increased in 64.6%,44.7%,43.2%,37.0%,29.5%,22.9%,20.8%,21.6%,13.6%,and 12.8%of patients,respectively.The incidence of ALT elevation in male patients was remarkably higher than that in females(P<0.01),while the incidences of AST,CK,and blood glucose elevations in severe patients were remarkably higher than those in moderate patients(P<0.05,respectively).Except for the mild patients,chest computed tomography showed characteristic pulmonary lesions.All the patients received antiviral drugs,38(79.2%)accepted traditional Chinese medicine,and 2(4.2%)received treatment of human umbilical-cord mesenchymal stem cells.On March 2,2020,48 patients with COVID-19 were all cured and discharged.CONCLUSION Based on our results,patients with COVID-19 often have multiple organ dysfunction or damage.The incidences of ALT elevation in males,and AST,CK,and blood glucose elevations in severe patients are remarkably higher.展开更多
‘Single shot'laser-ablation split-stream(SS-LASS)technique analyzing unpolished zircon grains makes their thin rims tenable for determination,which thus offers great potential in deciphering the timing of multipl...‘Single shot'laser-ablation split-stream(SS-LASS)technique analyzing unpolished zircon grains makes their thin rims tenable for determination,which thus offers great potential in deciphering the timing of multiple and short-lived episodes of anatexis and metamorphism in deeplysubducted continental crusts.Dominated granitic gneisses in the deeply subducted continental crust undergoing considerable fluid-melt activities persist multistage growth of zircon.Therefore,a comparative study of SS-LASS and laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)zircon dating was conducted on the granitic gneisses from the Sulu belt in this study.Zircons mostly show a core-mantle-rim structure with CL-bright rims thinner than 5μm.For LA-ICP-MS dating,relict magmatic zircon cores yield protolith ages of ca.756-747 Ma;whereas the dark mantles record synexhumation anatexis at ca.214 Ma.By contrast,according to the U-Pb dates,trace element features,zircon crystallization temperatures and geological context,SS-LASS zircon petrochronology deciphers three episodes of anatectic events,as follows:(i)the first episode of anatexis at ca.218-217 Ma dominated by phengite-breakdown melting,likely facilitating the exhumation of the UHP slice from mantle depth;(ii)the second episode of anatexis at ca.193–191 Ma indicating part of northern Dabie-Sulu belt was still“hot”because of buried in the thickened orogenic crust at that time;(iii)the third episode of anatexis(ca.162–161 Ma)consistent with the intrusion ages(ca.161–141 Ma)of the Jurassic to Cretaceous granitoids in this orogen,suggesting the initial collapse of the orogenic root of the Sulu belt occurred at Late Jurassic due to the Izanagi plate initially subducting beneath the margin of Eastern Asia.This study sheds new light upon the utilization of SS-LASS petrochronology deciphering multiple anatectic events in the deeply-subducted continental crust and supports us in better understanding the tectonic evolution of Dabie-Sulu Orogen.展开更多
In this paper, NOVA/NOVA-K codes are used to investigate the stability of Alfvén eigenmodes(AEs) in the China Fusion Engineering Test Reactor(CFETR). Firstly, the stability of AEs excited by energetic alpha parti...In this paper, NOVA/NOVA-K codes are used to investigate the stability of Alfvén eigenmodes(AEs) in the China Fusion Engineering Test Reactor(CFETR). Firstly, the stability of AEs excited by energetic alpha particles is investigated. For the fully non-inductive scenario, it is found that all AEs are stable, and the least stable toroidal mode number is n= 8. However, for the hybrid mode scenario, it is found that many AEs are unstable, and the least stable toroidal mode numbers are n= 7, 8. Secondly, the effect of energetic alpha-particle parameters and beam ions on AE stability is also presented. The threshold of the least stable AE is about βcrit,α = 1.12%,crit,less than the value of alpha-particle beta(βα=1.34%). The result demonstrates that the AEs excited by alpha particles are weakly unstable. The effect of the beam ions on AE stability is found to be very weak in CFETR.展开更多
Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible rel...Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum women.Methods A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this study.The urinary iodine concentration(UIC),TSH,VA,and VD were measured.Results The median UIC of total and lactating participants were 142.00µg/L and 139.95µg/L,respectively.The median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44μg/mL,and 24.04 ng/mL,respectively.No differences in the UIC were found between lactating and non-lactating mothers.UIC and TSH levels were significantly different among the three provinces.The rural UIC was higher than the urban UIC.Obese mothers had a higher UIC and a higher prevalence of excessive TSH.Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group.After adjustment,no linear correlation was observed between UIC and VA/VD.No interaction was found between vitamins A/D and UIC on TSH levels.Conclusion The mothers in the present study had no iodine deficiency.Region,area type,BMI,and VD may be related to the iodine status or TSH levels.展开更多
In addition to syenite ring dykes and multiple alkaline granite stocks, the sub-volcanic Houshihushan alkaline ring complex near Shanhaiguan, Qinhuangdao City, contains cone-sheets of two types： a majority filled wit...In addition to syenite ring dykes and multiple alkaline granite stocks, the sub-volcanic Houshihushan alkaline ring complex near Shanhaiguan, Qinhuangdao City, contains cone-sheets of two types： a majority filled with granite porphyry and a minority filled with quartz syenite porphyry. Many cone sheets show evidence of multiple magma intrusion events. Some granite porphyry sheets＇ multiple chilled margins display magmatic roll structures indicating that turbulent magma flowed up the fractures. In one upward-closing cone-sheet K-feldspar phenocrysts floated up through fluid granite porphyry magma and became concentrated at the top providing direct evidence of shallow-level crystal fractionation, confirmed by published rock analyses. Accreted lapilli with K-feldspar crystal cores occur only in the inner parts of a minority of cone-sheets and field relationships indicate that they must have formed beneath the ground surface. Similar lapilli occur in erupted ignimbrites preserved in the collapsed caldera. Voids between lapilli in cone-sheets indicate the presence of volumes of gas below the surface that could have flowed upwards as fast-moving hot gas streams. We propose a mechanism of formation that began with subterranean magmatic rolls with K-feldspar crystal cores that formed on dyke walls, and became detached. Then they were caught up in rising gas streams and erupted at the surface. Thus accreted lapilli formed underground, were erupted along with blobs of fluid glass in escaping gases, and transported over the surface in nuées ardentes, to settle and cool as ignimbrite flows.展开更多
BACKGROUND With the continuous development of laparoscopic techniques in recent years,laparoscopic total mesorectal excision(LapTME)and laparoscopic-assisted transanal total mesorectal excision(TaTME)have gradually be...BACKGROUND With the continuous development of laparoscopic techniques in recent years,laparoscopic total mesorectal excision(LapTME)and laparoscopic-assisted transanal total mesorectal excision(TaTME)have gradually become important surgical techniques for treating low-lying rectal cancer(LRC).However,there is still controversy over the efficacy and safety of these two surgical modalities in LRC treatment.AIM To compare the efficacy of LapTME vs TaTME in patients with LRC.METHODS Ninety-four patients with LRC who visited and were treated at the Affiliated Hengyang Hospital of Hunan Normal University&Hengyang Central Hospital between December 2022 and March 2024 were selected and divided into the LapTME(n=44)and TaTME(n=50)groups.Clinical operation indexes,postoperative recovery indicators,and postoperative complications were recorded.The anal resting pressure(ARP),anal maximum systolic pressure(MSP),and maximum tolerated volume(MTV)of the anal canal were also measured.The intestinal function of patients was evaluated by the Memorial Sloan Kettering Cancer Center(MSKCC)bowel function questionnaire.Serum norepinephrine(NE),adrenaline(AD),and cortisol(Cor)levels were measured.The Quality of Life Questionnaire Core 30(QLQC30)was used for quality of life assessment.RESULTS Compared with the LapTME group,the surgery time in the TaTME group was longer;intraoperative blood loss was low;time of anal exhaust,first postoperative ambulation,intestinal recovery,and hospital stay were shorter;and the distal incisal margin and specimen lengths were longer.The TaTME group also showed higher ARP,MSP,and MTV values and higher MSKCC and QLQ-C30 scores than the LapTME group 3 months postoperatively.Cor,AD,and NE levels were lower in the TaTME group than those in the LapTME group during recovery.CONCLUSION We demonstrated that TaTME better improved anal function,reduced postoperative stress,and accelerated postoperative recovery and,hence,was safer for patients with LRC.展开更多
To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compress...To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compression and uniaxial loading–unloading tests were conducted under five saturation levels.The effect of saturation on the mechanical properties and elastic energy density was analyzed,and a method for obtaining peak energy density was proposed.The effect of saturation on the energy evolution was examined,and the energy mechanism of water in preventing rockburst was revealed.The results indicate that an increase in saturation of red sandstone decreases the input energy density,elastic energy density,dissipated energy density,peak strength and peak strain;the compaction phase of the stress–strain curve becomes shorter;the failure mode transitions from X-conjugate oblique shear to single oblique shear;the variation in the debris ejection trajectory is as follows:radiation→X-ray→oblique upward parabola→horizontal parabola→oblique downward parabola;the degree of failure intensity and fragmentation is decreased gradually.Elastic energy density is interconnected with both saturation and stress but independent of the loading path.Saturation exhibits a dual effect on the energy storage property,i.e.,increasing saturation increases the energy storage efficiency and reduces the energy storage capacity.The ratio of peak elastic energy density to peak input energy density remains constant irrespective of saturation levels.Water prevents rockburst by decreasing the energy storage capacity of surrounding rock,alleviating the stress of surrounding rock to reduce energy storage,and elevating the energy release threshold of high-energy surrounding rock.The findings of this study contribute to understanding the effect of water on rock failure from an energy perspective,as well as provide theoretical guidance for rockburst prevention by water in deep tunnels.展开更多
The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multiallo...The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multialloying CoCrMoSi strategy has been developed to produce near-equiaxed grains of a modified Ti6Al4V(TC4)alloy for laser-directed energy deposition(LDED)based on computational thermodynamic and experimental approaches.The results show that the microstructure of the TC4alloy consists of large columnar β grains and α/α'laths with a high aspect ratio of 5.73,exhibiting a strong anisotropy of tensile properties.In contrast,the TC4-1.5%CoCrMoSi alloy is characterized by mixed columnarequiaxed β grains and near-equiaxed β grains with increased CoCrMoSi additions to 4.5%.Additionally,the α/α'laths are successively refined with the increase of CoCrMoSi content,showing an aspect ratio of smaller than4.31.However,an excess addition of CoCrMoSi leads to the formation of micro voids.After multi-alloyingCoCrMoSi,the number density of twins increases remarkably with a substantially reduced width,because of the increased lattice distortion and dislocation density together with the reducedβ→αphase transformation temperature.The anisotropy of the tensile properties can be effectively eliminated by adding 3 wt%CoCrMoSi with an exemplary strength-ductility combination,superior to the LDEDed-modified TC4 alloy in the literature reporting the tensile properties along both horizontal(X)and vertical(Z)directions.The underlaying mechanisms for the evolution of the microstructure and the tensile properties induced by multi-alloying CoCrMoSi were discussed in detail.展开更多
To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with...To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ.展开更多
Background:Insomnia is a prevalent clinical condition and Shangxia Liangji formula(SXLJF)is a well-established method of treatment.Nevertheless,the specific mechanism of action of SXLJF remains unclear.Methods:The mou...Background:Insomnia is a prevalent clinical condition and Shangxia Liangji formula(SXLJF)is a well-established method of treatment.Nevertheless,the specific mechanism of action of SXLJF remains unclear.Methods:The mouse model of insomnia was established by intraperitoneal injection of para-chlorophenylalanine.Forty-two mice were randomly divided into a negative control group,model group,SXLJF group(18.72 g/kg/day),and positive control group(diazepam,2 mg/kg)and treated with the corresponding drugs for 7 consecutive days.The open field test and pentobarbital-induced sleeping test were conducted.LC-MS-based untargeted metabolomics and network pharmacology were applied to explore the potential targets of SXLJF for treating insomnia.Finally,key targets were validated using RT-qPCR.Results:Behavioral tests demonstrated that SXLJF reduced the total distance,average velocity,central distance,and sleep latency,and prolonged sleep duration.Metabolomics and network pharmacology revealed potential targets,signaling pathways,metabolic pathways,and metabolites associated with the anti-insomnia effects of SXLJF.Specifically,tyrosine hydroxylase(TH)and tyrosine metabolism emerged as crucial metabolic pathways and targets,respectively.RT-qPCR results supported the role of TH in the mechanism of SXLJF in treating insomnia.Conclusion:In conclusion,TH and tyrosine metabolism may represent significant targets and pathways for SXLJF in treating insomnia.展开更多
Succinylcholine(SC)is a widely used depolarizing muscle relaxant,but improper use can lead to arrhythmias and,in severe cases,pose a life-threatening risk.Additionally,some criminals exploit SC for illicit activities....Succinylcholine(SC)is a widely used depolarizing muscle relaxant,but improper use can lead to arrhythmias and,in severe cases,pose a life-threatening risk.Additionally,some criminals exploit SC for illicit activities.Therefore,rapid SC detection is paramount for clinical practice and public safety.Currently,however,limited methods are available for the rapid detection of SC.A fluorescent indicator displacement assay sensor based on molecular recognition of an amide naphthotube was developed.This sensor enabled the rapid fluorescent detection of SC through competitive binding between SC and methylene blue with the amide naphthotube.The sensor exhibited exceptional sensitivity with a detection limit as low as 1.1μmol/L and a detection range of 1.1~60μmol/L,coupled with outstanding selectivity and robust stability.Furthermore,this sensor accurately determined SC levels in biological samples such as serum.In summary,this research provides a new solution for the rapid and accurate sensing of SC in complex matrices and offers new insights for the swift identification and detection of toxins.展开更多
The abiotic oxidation of divalentmanganese(Mn(Ⅱ))and the formation of Mn oxides are important geochemical processes,which control the mobility and availability of Mn as well as element cycling and pollutant behavior ...The abiotic oxidation of divalentmanganese(Mn(Ⅱ))and the formation of Mn oxides are important geochemical processes,which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils.It was found that iron(oxyhydr)oxides can catalyze Mn(Ⅱ)oxidation,but the effects of the coexisting dissolved organic matter(DOM)molecules on the catalysis of different iron(oxyhydr)oxides for Mn(Ⅱ)oxidation are poorly understood.Herein,we investigated Mn(Ⅱ)oxidation under the impacts of the interactions between iron(oxyhydr)oxides(i.e.,ferrihydrite,goethite and hematite)and DOM molecules.Simultaneously,we elucidated the variations of DOM composition and properties.Our results indicated that the catalysis of iron(oxyhydr)oxides for Mn(Ⅱ)oxidation was significantly inhibited by DOM.Moreover,DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(Ⅱ)oxidation and the formation of Mn oxides(e.g.,hausmannite and buserite)relative to goethite and hematite,whichwas partially because of the higher electron transfer capacities of ferrihydrite.Meanwhile,DOM molecules with high nominal oxidation state of carbon(NOSC),molecular weight,unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides,including the oxygenated phenols and polyphenols.The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics.Furthermore,NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present.Overall,our research contributes to understanding Mn(Ⅱ)oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.展开更多
In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power....In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power.The system utilizes a titanium dioxide nanorod array(TNR)photoelectrode coupled with a silicon solar cell to optimize electron transport,while the cathode is composed of a carbon fiber coated with carboxylated carbon nanotubes(CCNT/CF),which efficiently reduce UO_(2)^(2+).The results demonstrate significant removal efficiency of uranium(complete removal in 25 min at a rate constant of~0.248 min^(-1)),as well as substantial degradation of organic impurities.Furthermore,the system generates sufficient power output to light an LED lamp and exhibits superior performance under various complex wastewater conditions,including simulated seawater and real uranium tailings wastewater.These findings underscore the potential of the SD-PEC system as a versatile approach for sustainable treatment and energy recovery of radioactive wastewater.The significance of this research extends to global environmental challenges,offering an innovative solution for managing radioactive wastewater while simultaneously contributing to renewable energy generation.展开更多
基金financially supported by the Provincial Natural Science Foundation of Hunan(Nos.2019JJ50831,2023JJ30505 and 2023JJ40541)the China Postdoctoral Science Foundation(Nos.2017M622597 and 2021M690591)+2 种基金the Open Research Fund Program of Fundamental Science on Radioactive Geology and Exploration Technology Laboratory(East China University of Technology)(No.2022RGET04)the National Foreign Expert Project(No.G2022029012L)the National Nature Science Foundation of China(No.41002022)。
文摘The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.
基金supported by the National Natural Science Foundation of China(No.12175102)Hunan Provincial Natural Science Foundation(No.2022JJ40346)the 2022 Hunan Provincial University Student Innovation and Entrepreneurship Training Program(No.S202210555144).
文摘Owing to the inherent limitation of the internal pulse ionization chamber within the AlphaGUARD PQ2000 radon monitor,that is,its inability to discriminate the energy levels of α particles,the ingress of^(220)Rn from the surrounding environment,along with its decay progeny,poses a substantive challenge in accurately determining the^(222)Rn concentration in the measurement outcomes.Among these,the protracted influence primarily stems from the two enduring decay progenies,namely^(212)Pb with a half-life of 10.64 h and^(212)Bi with a half-life of 60.54 min.This study explored the influence of^(220)Rn progeny on the measurement results of an AlphaGUARD PQ2000 radon monitor by developing a theoretical calculation model.The response coefficient related to the residual^(220)Rn progeny within the AlphaGUARD PQ2000 radon monitor was experimentally validated.In addition,this study investigated the effects of temperature and wind speed on the sensitivity of the instrument to^(220)Rn gas.The research findings revealed commendable agreement between the experimentally measured response coefficients of the residual^(220)Rn progeny and the corresponding values derived from the theoretical model.Notably,both the response coefficients of the AlphaGUARD PQ2000 radon monitor to^(220)Rn gas and its internal residual^(220)Rn progeny increased with elevated temperatures and increased wind speeds,providing a reference for correcting the impact of^(220)Rn and its progeny on the measurement results of^(222)Rn concentration obtained using the AlphaGUARD PQ2000 radon monitor.
基金supported by the National Natural Science Foundation of China(No.12305385)Key Projects of Scientific Research of the Hunan Provincial Department of Education(22A0310)the Research Startup Project of University of South China(220XQD025).
文摘In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy response)of engineered polycarbonate films irradiated with an electron beam(0–600 kGy)were investigated using photoluminescence spectroscopy.The results show a linear relationship between photoluminescence intensity and radiation dose when the thickness of the polycarbonate film is 0.3 mm.A higher fluorescence intensity can be obtained by preheating at 60℃ for 180 min before photoluminescence spectrum analysis.As the temperature during spectral testing and the ambient humidity(during and after irradiation)increased,the photoluminescence intensity of the polycarbonate films decreased.The photoluminescence intensity deviation of the polycarbonate films produced within the same batch at 100 kGy is 2.73%.After ten times of repeated excitations and readouts,the coefficients of variation in photoluminescence intensity are less than 8.6%,and the linear correlation coefficient between photoluminescence intensity and irradiation dose is 0.965 in the dose capture range of 20–600 kGy.Within 60 days of irradiation,the photoluminescence intensity of the polycarbonate film decreased to 60%of the initial value.The response of the 0.3 mm polycarbonate films to electron beams with energies exceeding 3.5 MeV does not differ significantly.This comprehensive analysis indicates the potential of polycarbonate films as a high-radiation dose detection material.
基金support from National Key Research and Development Program of China(2024YFE0217100)the National Natural Science Foundation of China(21905006,22261160370,and 62105075)+7 种基金the Guangdong Provincial Science and Technology Plan(2021A0505110003)the Natural Science Foundation of Hunan Province,China(2023JJ50132)Guangxi Department of Science and Technology(2020GXNSFBA159049 and AD19110030)the Shenzhen Science and Technology Program(SGDX20230116093205009,JCYJ20220818100211025 and 2022378670)the Natural Science Foundation of Top Talent of SZTU(GDRC202343)financial support of Innovation and Technology Fund(#GHP/245/22SZ)The University Grant Council of the University of Hong Kong(grant No.2302101786)General Research Fund(grant Nos.17200823 and 17310624)from the Research Grants Council.
文摘Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.
基金Under the auspices of National Natural Science Foundation of China(No.40901289)Major State Basic Research Development Program of China(No.2009CB421104),U.S.National Science Foundation
文摘Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable.In this study,this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains,Shaanxi Province,China.The network of reserves was established mainly for the conservation of the giant panda,a species considered as a surrogate for the conservation of many other endangered species in the region.The habitat suitability of nine protected species,including the giant panda,was modeled by using Maximum Entropy(MAXENT)and their spatial congruence was analyzed.Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones(i.e.,core,buffer and experimental zones).Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species,and giant panda reserves protect a relatively high proportion of the habitat of other protected species.Therefore,giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region.However,a large area of suitable habitat was excluded from the nature reserve network.In addition,four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves.It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones,thus,is being affected by human activities.To increase their conservation effectiveness,nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species.The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.
基金supported by the 12th Five-Year Major National Science and Technology Projects of China (No.2011ZX10004-001)Natural Science Foundation of China (31100105)
文摘Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the representative strain of B. afzelii in China, was analyzed by SDS-PAGE, electro transfer and irnmunoblotting assays. The molecular weights of the protein bands of FP1 were analyzed by Gel-Pro analysis software. In a study using 451 serum samples （159 patients with Lyme disease and 292 controls）, all observed bands were recorded. The accuracy of the WB as a diagnostic test was established by using the ROC curve and Youden index. Results Criteria for a positive diagnosis of Lyme disease were established as at least one band of P83/100, P58, P39, OspB, OspA, P30, P28, OspC, P17, and P14 in the IgG test and at least one band of P83/100, P58, P39, OspA, P30, P28, OspC, P17, and P41 in the IgM test. For IgG criteria, the sensitivity, specificity and Youden index were 69.8%, 98.3%, and 0.681, respectively; for IgM criteria, the sensitivity, specificity and Youden index were 47%, 94.2%, and 0.412, respectively.
基金We thank all the students who participated in our study.
文摘Purpose:This study aimed to investigate the current status of self-differentiation and professional adaptability among undergraduate nursing students,to analyze the relationship between these two variables,and to provide recommendations for nursing educators.Methods:A total of 341 nursing undergraduate students at the University of South China were investigated using the Differentiation of Self Inventory and the Professional Adaptability Scale for college students.Results:The mean scores of self-differentiation and professional adaptability were 3.70±0.60 and 2.87±0.37,respectively,and the two variables were positively correlated(P<0.01).Conclusion:The level of self-differentiation of undergraduate nursing studentsaffects their professional adaptability.Nursing educators should consider the characteristics of self-differentiation of undergraduate nursing students in developing measures to improve their professional adaptability.
基金Supported by the Novel Coronavirus Pneumonia Emergency Project of University of South China,No.2020-15 and No.2020-25the Hengyang Science and Technology Plan Project-Basic Research Project of Prevention and Treatment of the Novel Coronavirus Pneumonia,No.202010031577+2 种基金the Scientific Research Project of Hunan Provincial Health and Family Planning Commission,No.A2017015the Natural Science Foundation of Hunan Province,China,No.2016JJ5010the National Natural Science Foundation of China,No.81373465.
文摘BACKGROUND In December 2019,an ongoing outbreak of coronavirus disease 2019(COVID-19)was first identified in Wuhan,China.The characteristics of COVID-19 patients treated in local hospitals in Wuhan are not fully representative of patients outside Wuhan.Therefore,it is highly essential to analyze the epidemiological and clinical characteristics of COVID-19 in areas outside Wuhan or Hubei Province.To date,a limited number of studies have concentrated on the epidemiological and clinical characteristics of COVID-19 patients with different genders,clinical classification,and with or without basic diseases.AIM To study the epidemiological and clinical characteristics of COVID-19 patients in Hengyang(China)and provide a reliable reference for the prevention and control of COVID-19.METHODS From January 16 to March 2,2020,a total of 48 confirmed cases of COVID-19 were reported in Hengyang,and those cases were included in this study.The diagnostic criteria,clinical classification,and discharge standard related to COVID-19 were in line with the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 7)released by National Health Commission and National Administration of Traditional Chinese Medicine.The presence of SARS-CoV-2 in pharyngeal swab specimens was detected by quantitative reverse transcription polymerase chain reaction.All the data were imported into the excel worksheet and statistically analyzed by using SPSS 25.0 software.RESULTS A total of 48 cases of COVID-19 were collected,of which 1 was mild,38 were moderate,and 9 were severe.It was unveiled that there were 31(64.6%)male patients and 17(35.4%)female patients,with a female-to-male ratio of 1.82:1.The range of age of patients with COVID-19 was dominantly 30-49 years old[25(52.1%)of 48],followed by those aged over 60 years old[11(22.9%)].Besides,29.2%(14 of 48)of patients had basic diseases,and 57.2%(8 of 14)of patients with basic diseases were aged over 60 years old.The occupations of 48 COVID-19 patients were mainly farmers working in agricultural production[15(31.5%)of 48],rural migrant workers from Hengyang to Wuhan[15(31.5%)],and service workers operating in the service sector[8(16.7%)].The mean latent period was 6.86±3.57 d,and the median was 7[interquartile range(IQR):4-9]d.The mean time from onset of symptoms to the first physician visit was 3.38±2.98(95%CI:2.58-9.18)d,with a median of 2(IQR:1-5)d,and the mean time from hospital admission to confirmed diagnosis was 2.29±2.11(95%CI:1.18-6.42)d,with a median of 2(IQR:1-3)d.The main symptoms were fever[43(89.6%)of 48],cough and expectoration[41(85.4%)],fatigue[22(45.8%)],and chills[22(45.8%)].Other symptoms included poor appetite[13(27.1%)],sore throat[9(18.8%)],dyspnea[9(18.8%)],diarrhea[7(14.6%)],dizziness[5(10.4%)],headache[5(10.4%)],muscle pain[5(10.4%)],nausea and vomiting[4(8.3%)],hemoptysis[4(8.3%)],and runny nose[1(2.1%)].The numbers of peripheral blood leukocytes,lymphocytes,and eosinophils were significantly reduced in the majority of the patients.The levels of C-reactive protein,fibrinogen,blood glucose,lactate dehydrogenase,Ddimer,alanine aminotransferase(ALT),aspartate aminotransferase(AST),gamma-glutamyl transferase(γ-GT),myoglobin(MB),and creatine kinase(CK)were increased in 64.6%,44.7%,43.2%,37.0%,29.5%,22.9%,20.8%,21.6%,13.6%,and 12.8%of patients,respectively.The incidence of ALT elevation in male patients was remarkably higher than that in females(P<0.01),while the incidences of AST,CK,and blood glucose elevations in severe patients were remarkably higher than those in moderate patients(P<0.05,respectively).Except for the mild patients,chest computed tomography showed characteristic pulmonary lesions.All the patients received antiviral drugs,38(79.2%)accepted traditional Chinese medicine,and 2(4.2%)received treatment of human umbilical-cord mesenchymal stem cells.On March 2,2020,48 patients with COVID-19 were all cured and discharged.CONCLUSION Based on our results,patients with COVID-19 often have multiple organ dysfunction or damage.The incidences of ALT elevation in males,and AST,CK,and blood glucose elevations in severe patients are remarkably higher.
基金supported by National Natural Science Foundation of China(Nos.42072228,42102060,41902036,41572182)China Postdoctoral Science Foundation(No.2021M692983)+4 种基金the Chinese Ministry of Education(No.BP0719022)the Most Special Fund(Nos.MSFGPMR02-3,MSFGPMR30)Open funds from the State Key Laboratory of Geological Processes and Mineral ResourcesChina University of Geosciences(Nos.GPMR201703,GPMR201704 and GPMR201903)the Fundamental Research Funds for National University(No.CUG-G1323511572)。
文摘‘Single shot'laser-ablation split-stream(SS-LASS)technique analyzing unpolished zircon grains makes their thin rims tenable for determination,which thus offers great potential in deciphering the timing of multiple and short-lived episodes of anatexis and metamorphism in deeplysubducted continental crusts.Dominated granitic gneisses in the deeply subducted continental crust undergoing considerable fluid-melt activities persist multistage growth of zircon.Therefore,a comparative study of SS-LASS and laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)zircon dating was conducted on the granitic gneisses from the Sulu belt in this study.Zircons mostly show a core-mantle-rim structure with CL-bright rims thinner than 5μm.For LA-ICP-MS dating,relict magmatic zircon cores yield protolith ages of ca.756-747 Ma;whereas the dark mantles record synexhumation anatexis at ca.214 Ma.By contrast,according to the U-Pb dates,trace element features,zircon crystallization temperatures and geological context,SS-LASS zircon petrochronology deciphers three episodes of anatectic events,as follows:(i)the first episode of anatexis at ca.218-217 Ma dominated by phengite-breakdown melting,likely facilitating the exhumation of the UHP slice from mantle depth;(ii)the second episode of anatexis at ca.193–191 Ma indicating part of northern Dabie-Sulu belt was still“hot”because of buried in the thickened orogenic crust at that time;(iii)the third episode of anatexis(ca.162–161 Ma)consistent with the intrusion ages(ca.161–141 Ma)of the Jurassic to Cretaceous granitoids in this orogen,suggesting the initial collapse of the orogenic root of the Sulu belt occurred at Late Jurassic due to the Izanagi plate initially subducting beneath the margin of Eastern Asia.This study sheds new light upon the utilization of SS-LASS petrochronology deciphering multiple anatectic events in the deeply-subducted continental crust and supports us in better understanding the tectonic evolution of Dabie-Sulu Orogen.
基金supported by National Natural Science Foundation of China(Nos.11947056 and 12005100)the Natural Science Foundation of Hunan Province(No.2020JJ5468)+2 种基金the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(No.2019KFY15)the Hunan Nuclear Fusion International Science and Technology Innovation Cooperation Base(No.2018WK4009)the Key Scientific Research Program of Education Department of Hunan Province(No.20A417).
文摘In this paper, NOVA/NOVA-K codes are used to investigate the stability of Alfvén eigenmodes(AEs) in the China Fusion Engineering Test Reactor(CFETR). Firstly, the stability of AEs excited by energetic alpha particles is investigated. For the fully non-inductive scenario, it is found that all AEs are stable, and the least stable toroidal mode number is n= 8. However, for the hybrid mode scenario, it is found that many AEs are unstable, and the least stable toroidal mode numbers are n= 7, 8. Secondly, the effect of energetic alpha-particle parameters and beam ions on AE stability is also presented. The threshold of the least stable AE is about βcrit,α = 1.12%,crit,less than the value of alpha-particle beta(βα=1.34%). The result demonstrates that the AEs excited by alpha particles are weakly unstable. The effect of the beam ions on AE stability is found to be very weak in CFETR.
基金funded by the National Health Commission of People’s Republic of China Medical Reform Major Program‘2016-2017 National Nutrition and Health Surveillance of Children and Lactating Women’Major Public Health Project‘Survey and Evaluation of Iodine Nutrition and Thyroid Diseases of Chinese Population’[131031107000160007].
文摘Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum women.Methods A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this study.The urinary iodine concentration(UIC),TSH,VA,and VD were measured.Results The median UIC of total and lactating participants were 142.00µg/L and 139.95µg/L,respectively.The median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44μg/mL,and 24.04 ng/mL,respectively.No differences in the UIC were found between lactating and non-lactating mothers.UIC and TSH levels were significantly different among the three provinces.The rural UIC was higher than the urban UIC.Obese mothers had a higher UIC and a higher prevalence of excessive TSH.Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group.After adjustment,no linear correlation was observed between UIC and VA/VD.No interaction was found between vitamins A/D and UIC on TSH levels.Conclusion The mothers in the present study had no iodine deficiency.Region,area type,BMI,and VD may be related to the iodine status or TSH levels.
基金financially supported by the National Nature Science Foundation of China (No. 41272079)
文摘In addition to syenite ring dykes and multiple alkaline granite stocks, the sub-volcanic Houshihushan alkaline ring complex near Shanhaiguan, Qinhuangdao City, contains cone-sheets of two types： a majority filled with granite porphyry and a minority filled with quartz syenite porphyry. Many cone sheets show evidence of multiple magma intrusion events. Some granite porphyry sheets＇ multiple chilled margins display magmatic roll structures indicating that turbulent magma flowed up the fractures. In one upward-closing cone-sheet K-feldspar phenocrysts floated up through fluid granite porphyry magma and became concentrated at the top providing direct evidence of shallow-level crystal fractionation, confirmed by published rock analyses. Accreted lapilli with K-feldspar crystal cores occur only in the inner parts of a minority of cone-sheets and field relationships indicate that they must have formed beneath the ground surface. Similar lapilli occur in erupted ignimbrites preserved in the collapsed caldera. Voids between lapilli in cone-sheets indicate the presence of volumes of gas below the surface that could have flowed upwards as fast-moving hot gas streams. We propose a mechanism of formation that began with subterranean magmatic rolls with K-feldspar crystal cores that formed on dyke walls, and became detached. Then they were caught up in rising gas streams and erupted at the surface. Thus accreted lapilli formed underground, were erupted along with blobs of fluid glass in escaping gases, and transported over the surface in nuées ardentes, to settle and cool as ignimbrite flows.
基金Supported by Health Research Project of Hunan Provincial Health Commission,No.D202315018915.
文摘BACKGROUND With the continuous development of laparoscopic techniques in recent years,laparoscopic total mesorectal excision(LapTME)and laparoscopic-assisted transanal total mesorectal excision(TaTME)have gradually become important surgical techniques for treating low-lying rectal cancer(LRC).However,there is still controversy over the efficacy and safety of these two surgical modalities in LRC treatment.AIM To compare the efficacy of LapTME vs TaTME in patients with LRC.METHODS Ninety-four patients with LRC who visited and were treated at the Affiliated Hengyang Hospital of Hunan Normal University&Hengyang Central Hospital between December 2022 and March 2024 were selected and divided into the LapTME(n=44)and TaTME(n=50)groups.Clinical operation indexes,postoperative recovery indicators,and postoperative complications were recorded.The anal resting pressure(ARP),anal maximum systolic pressure(MSP),and maximum tolerated volume(MTV)of the anal canal were also measured.The intestinal function of patients was evaluated by the Memorial Sloan Kettering Cancer Center(MSKCC)bowel function questionnaire.Serum norepinephrine(NE),adrenaline(AD),and cortisol(Cor)levels were measured.The Quality of Life Questionnaire Core 30(QLQC30)was used for quality of life assessment.RESULTS Compared with the LapTME group,the surgery time in the TaTME group was longer;intraoperative blood loss was low;time of anal exhaust,first postoperative ambulation,intestinal recovery,and hospital stay were shorter;and the distal incisal margin and specimen lengths were longer.The TaTME group also showed higher ARP,MSP,and MTV values and higher MSKCC and QLQ-C30 scores than the LapTME group 3 months postoperatively.Cor,AD,and NE levels were lower in the TaTME group than those in the LapTME group during recovery.CONCLUSION We demonstrated that TaTME better improved anal function,reduced postoperative stress,and accelerated postoperative recovery and,hence,was safer for patients with LRC.
基金supported by the National Natural Science Foundation of China(52104133,52304227)the Natural Science Foundation of Hunan Province(2021JJ40465,2023JJ40548)the Opening Foundation of the State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines(SKLMRDPC20KF03).
文摘To investigate the effect of saturation on the storage-dissipation properties and failure characteristics of red sandstone,as well as the energy mechanism of rockburst prevention by water,a series of uniaxial compression and uniaxial loading–unloading tests were conducted under five saturation levels.The effect of saturation on the mechanical properties and elastic energy density was analyzed,and a method for obtaining peak energy density was proposed.The effect of saturation on the energy evolution was examined,and the energy mechanism of water in preventing rockburst was revealed.The results indicate that an increase in saturation of red sandstone decreases the input energy density,elastic energy density,dissipated energy density,peak strength and peak strain;the compaction phase of the stress–strain curve becomes shorter;the failure mode transitions from X-conjugate oblique shear to single oblique shear;the variation in the debris ejection trajectory is as follows:radiation→X-ray→oblique upward parabola→horizontal parabola→oblique downward parabola;the degree of failure intensity and fragmentation is decreased gradually.Elastic energy density is interconnected with both saturation and stress but independent of the loading path.Saturation exhibits a dual effect on the energy storage property,i.e.,increasing saturation increases the energy storage efficiency and reduces the energy storage capacity.The ratio of peak elastic energy density to peak input energy density remains constant irrespective of saturation levels.Water prevents rockburst by decreasing the energy storage capacity of surrounding rock,alleviating the stress of surrounding rock to reduce energy storage,and elevating the energy release threshold of high-energy surrounding rock.The findings of this study contribute to understanding the effect of water on rock failure from an energy perspective,as well as provide theoretical guidance for rockburst prevention by water in deep tunnels.
基金financially supported by the National Natural Science Foundation of China(No.52375341)Hunan Provincial Natural Science Foundation(No.2022JJ30494)
文摘The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multialloying CoCrMoSi strategy has been developed to produce near-equiaxed grains of a modified Ti6Al4V(TC4)alloy for laser-directed energy deposition(LDED)based on computational thermodynamic and experimental approaches.The results show that the microstructure of the TC4alloy consists of large columnar β grains and α/α'laths with a high aspect ratio of 5.73,exhibiting a strong anisotropy of tensile properties.In contrast,the TC4-1.5%CoCrMoSi alloy is characterized by mixed columnarequiaxed β grains and near-equiaxed β grains with increased CoCrMoSi additions to 4.5%.Additionally,the α/α'laths are successively refined with the increase of CoCrMoSi content,showing an aspect ratio of smaller than4.31.However,an excess addition of CoCrMoSi leads to the formation of micro voids.After multi-alloyingCoCrMoSi,the number density of twins increases remarkably with a substantially reduced width,because of the increased lattice distortion and dislocation density together with the reducedβ→αphase transformation temperature.The anisotropy of the tensile properties can be effectively eliminated by adding 3 wt%CoCrMoSi with an exemplary strength-ductility combination,superior to the LDEDed-modified TC4 alloy in the literature reporting the tensile properties along both horizontal(X)and vertical(Z)directions.The underlaying mechanisms for the evolution of the microstructure and the tensile properties induced by multi-alloying CoCrMoSi were discussed in detail.
基金supported by the National Natural Science Foundation of China (Grant Nos.52304227 and 52104133)Scientific and Technological Research Platform for Disaster Prevention and Control of Deep Coal Mining (Anhui University of Science and Technology) (Grant No.DPDCM2208).
文摘To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ.
基金Science Foundation of Hunan Province(2021JJ40510)General Guidance Project of Hunan Health Commission(202203074169)+1 种基金Clinical Medical Technology Innovation Guidance Project of Hunan Province(2021SK51901)and Key Guiding Projects of Hunan Health Commission(20201918)for supporting this study.
文摘Background:Insomnia is a prevalent clinical condition and Shangxia Liangji formula(SXLJF)is a well-established method of treatment.Nevertheless,the specific mechanism of action of SXLJF remains unclear.Methods:The mouse model of insomnia was established by intraperitoneal injection of para-chlorophenylalanine.Forty-two mice were randomly divided into a negative control group,model group,SXLJF group(18.72 g/kg/day),and positive control group(diazepam,2 mg/kg)and treated with the corresponding drugs for 7 consecutive days.The open field test and pentobarbital-induced sleeping test were conducted.LC-MS-based untargeted metabolomics and network pharmacology were applied to explore the potential targets of SXLJF for treating insomnia.Finally,key targets were validated using RT-qPCR.Results:Behavioral tests demonstrated that SXLJF reduced the total distance,average velocity,central distance,and sleep latency,and prolonged sleep duration.Metabolomics and network pharmacology revealed potential targets,signaling pathways,metabolic pathways,and metabolites associated with the anti-insomnia effects of SXLJF.Specifically,tyrosine hydroxylase(TH)and tyrosine metabolism emerged as crucial metabolic pathways and targets,respectively.RT-qPCR results supported the role of TH in the mechanism of SXLJF in treating insomnia.Conclusion:In conclusion,TH and tyrosine metabolism may represent significant targets and pathways for SXLJF in treating insomnia.
文摘Succinylcholine(SC)is a widely used depolarizing muscle relaxant,but improper use can lead to arrhythmias and,in severe cases,pose a life-threatening risk.Additionally,some criminals exploit SC for illicit activities.Therefore,rapid SC detection is paramount for clinical practice and public safety.Currently,however,limited methods are available for the rapid detection of SC.A fluorescent indicator displacement assay sensor based on molecular recognition of an amide naphthotube was developed.This sensor enabled the rapid fluorescent detection of SC through competitive binding between SC and methylene blue with the amide naphthotube.The sensor exhibited exceptional sensitivity with a detection limit as low as 1.1μmol/L and a detection range of 1.1~60μmol/L,coupled with outstanding selectivity and robust stability.Furthermore,this sensor accurately determined SC levels in biological samples such as serum.In summary,this research provides a new solution for the rapid and accurate sensing of SC in complex matrices and offers new insights for the swift identification and detection of toxins.
基金supported by the National Natural Science Foundation of China(Nos.42207309 and 22306087)the Natural Science Foundation of Hunan Province(Nos.2022JJ40369 and 2023JJ40547)the Program for Education Department of Hunan Province,China(No.21B0405).
文摘The abiotic oxidation of divalentmanganese(Mn(Ⅱ))and the formation of Mn oxides are important geochemical processes,which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils.It was found that iron(oxyhydr)oxides can catalyze Mn(Ⅱ)oxidation,but the effects of the coexisting dissolved organic matter(DOM)molecules on the catalysis of different iron(oxyhydr)oxides for Mn(Ⅱ)oxidation are poorly understood.Herein,we investigated Mn(Ⅱ)oxidation under the impacts of the interactions between iron(oxyhydr)oxides(i.e.,ferrihydrite,goethite and hematite)and DOM molecules.Simultaneously,we elucidated the variations of DOM composition and properties.Our results indicated that the catalysis of iron(oxyhydr)oxides for Mn(Ⅱ)oxidation was significantly inhibited by DOM.Moreover,DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(Ⅱ)oxidation and the formation of Mn oxides(e.g.,hausmannite and buserite)relative to goethite and hematite,whichwas partially because of the higher electron transfer capacities of ferrihydrite.Meanwhile,DOM molecules with high nominal oxidation state of carbon(NOSC),molecular weight,unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides,including the oxygenated phenols and polyphenols.The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics.Furthermore,NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present.Overall,our research contributes to understanding Mn(Ⅱ)oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.
基金supported by the National Natural Science Foundation of China(Nos.52170083,51808143)the Science and Technology Innovation Program of Hunan Province(No.2022RC1125)the Hunan Provincial Natural Science Foundation of China(No.2021JJ20007)。
文摘In this study,we present a self-driven photoelectrocatalytic(SD-PEC)system that effectively treats complex uranium-bearing wastewaters for both uranium recovery and organic matter decomposition while generating power.The system utilizes a titanium dioxide nanorod array(TNR)photoelectrode coupled with a silicon solar cell to optimize electron transport,while the cathode is composed of a carbon fiber coated with carboxylated carbon nanotubes(CCNT/CF),which efficiently reduce UO_(2)^(2+).The results demonstrate significant removal efficiency of uranium(complete removal in 25 min at a rate constant of~0.248 min^(-1)),as well as substantial degradation of organic impurities.Furthermore,the system generates sufficient power output to light an LED lamp and exhibits superior performance under various complex wastewater conditions,including simulated seawater and real uranium tailings wastewater.These findings underscore the potential of the SD-PEC system as a versatile approach for sustainable treatment and energy recovery of radioactive wastewater.The significance of this research extends to global environmental challenges,offering an innovative solution for managing radioactive wastewater while simultaneously contributing to renewable energy generation.
