BACKGROUND Large number of decompensated liver cirrhosis patients in China have been diagnosed with hepatitis B virus(HBV).Human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)can possibly cure decompensated l...BACKGROUND Large number of decompensated liver cirrhosis patients in China have been diagnosed with hepatitis B virus(HBV).Human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)can possibly cure decompensated liver cirrhosis because of their self-renewal and multidirectional differentiation potential.AIM To explore the safety and effect of treating liver cirrhosis with HBV by hUC-MSCs.METHODS Twenty-four participants were recruited,divided into 3 groups,and injected with different amounts of hUC-MSCs via the peripheral vein.Therapy was administered 3 times.A 24-week follow-up examination of each patient’s liver function,coagulation function,general condition,and immune system was performed.Adverse events were also recorded.A 2-year survival assessment was subsequently performed.RESULTS Infusion therapy rapidly improved liver function.Serum albumin transiently increased on days 57 and 85 but returned to baseline by day 169,while prothrombin time activity demonstrated sustained improvement from day 29 through day 169.Interleukin-8 levels decreased persistently throughout treatment.All dosage groups achieved 100%6-month survival;2-year survival rates were 66.7%(low-dose),100%(medium-dose),and 87.5%(high-dose).The interaction between dosage and efficacy was weak.Notably,the improvement in liver function was statistically significant and sustained for almost 3 months,suggesting clinically meaningful therapeutic durability.CONCLUSION hUC-MSCs can be considered a safe treatment for patients with decompensated liver cirrhosis associated with HBV.However,larger-scale randomized controlled trials are needed to prove its therapeutic effect.展开更多
In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong...In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong” with RT-PCR and RACE methods and named as RrGlu. The full-length cDNA is 1380 bp with an open reading frame of 1041 bp, encoding 346 amino acids. The derived protein has a molecular weight of 37.85 kD, a calculated pI of 9.12, a pfam00332 conserved domain at position 36 - 345, and belongs to glycosyl hydrolase family 17. The derived protein is a hydrophilic protein secreted into the vacuole. There is a signal peptide cleavage site at position 34 - 35, a transmembrane domain at position 13 - 32, six Ser phosphorylation sites, three Thr phosphorylation sites, three Tyr phosphorylation sites, one N-glycosylation site, and five O-glycosylation sites. There are 31.50% α-helixes, 30.92% random coil, 25.14% extended peptide chain, and 12.43% β-corner structure. This protein and the Glu protein from eight other species, including Prunus persica, share a sequence homology of greater than 72%;all of the proteins contain a pfam00332 conserved domain and a β-1,3-glucanase active center sequence (LIVM)-X-(LIVMFYW)3-(STAG)-E-(ST)-G-W-P-(ST)-X-G. Furthermore, their phylogenetic relationships are consistent with their traditional classifications. These results were meaningful to reveal the molecular mechanism of R. rugosa pollination incompatibility and improve the theory and techniques of breeding ornamental R. rugosa.展开更多
The geographical condition of Qingdao, China is relatively special;the transport of various inland pollutants, the emissions of marine aerosol and local pollutants will have an impact on the changes of atmospheric aer...The geographical condition of Qingdao, China is relatively special;the transport of various inland pollutants, the emissions of marine aerosol and local pollutants will have an impact on the changes of atmospheric aerosol concentration. By using the stability classification method, trajectory clustering analysis and the NOAA HYSPLIT model, the seasonal distribution characteristics of atmospheric inhalable particulate matter concentration in Qingdao, China and its relationship with meteorological conditions, mixed layer height, and the seasonal characteristics of Qingdao pollutant transport were analyzed. The results show that the variation trends of PM2.5 and PM10 were about the same, and there are obvious seasonal differences, which are high in winter and spring, and low in summer and autumn. The concentration of inhalable particulate matter has a negative correlation with temperature, wind speed and relative humidity. The concentration of inhalable particulate matter is distinct in different relative humidity ranges. When the wind speed is less than 3 - 4 m/s, there are more inhalable particles, while the mass concentration shows obvious reduction with the wind speed more than 4 m/s. There is a significant negative correlation between the mass concentration of pollutants and the daily maximum mixed layer height. The larger the concentration of pollutants, the smaller the thickness of the daily largest mixed layer. Conversely, the smaller the mass concentration of pollutants, the larger the thickness of the daily largest mixed layer. The pollutant transport in Qingdao has obvious seasonal characteristics. The air mass in spring, autumn and winter is mainly medium-long distance transport from Mongolia and southern Russia, and medium-short distance transport from Inner Mongolia and northeast of China. The source of air masses in summer is mainly transported from the eastern and sea areas.展开更多
In many wild species, seeds are dormancy at maturity and will not germinate even under favorable environment conditions. Dormancy is a complex trail that is determined by many factors. Some studies have shown that col...In many wild species, seeds are dormancy at maturity and will not germinate even under favorable environment conditions. Dormancy is a complex trail that is determined by many factors. Some studies have shown that cold stratification and the application of gibberellic acid (GA) can break seed dormancy and promote seed germination. The present study investigated the causes of plant dormancy and the effect of cold stratification and different concentrations of exogenous GA<sub>3</sub> in regulating Cephalotaxus sinensis seed germination. Results showed that C. Sinensis seeds have good water permeability, which suggested that seed coats were not the main cause that inhibited the seed germination. There were germination inhibitions in all parts of seeds, and the order of inhibitory effect was: testa < endosperm (embryo), which indicated that existence of germination inhibitions was the main reason causing seed dormancy. Endogenous GAs and IAA (indole-3-acetic acid) content increased, while ABA (abscisic acid) content decreased over the experiments. ZR (zeatin riboside) content decreased in the early phase of cold stratification, but rebounded by the end of the experimental period. The changes of endogenous hormone indicated that GA, IAA and ZR played a positive role in seed germination, whereas ABA was associated with seed dormancy. Besides, the relative ratio of GA/ABA, IAA/ABA and ZR/ABA may play a more important role than their absolute level during the seed development.展开更多
This study has employed the master chemical mechanism(MCM)to investigate the influence of the ozone oxidation pathways in the atmospheric formation of H_(2)SO_(4)from shortchain olefins in industrialized areas.In-situ...This study has employed the master chemical mechanism(MCM)to investigate the influence of the ozone oxidation pathways in the atmospheric formation of H_(2)SO_(4)from shortchain olefins in industrialized areas.In-situ H_(2)SO_(4)formation data were obtained using a high-resolution chemical ionization time-of-flight mass spectrometer,and the simulated H_(2)SO_(4)concentrations calculated using updated parameters for the MCM model exhibited good agreementwith observations.In the simulation analysis of different reaction pathways involved in H_(2)SO_(4)formation,hydroxyl radicals were found to dominate H_(2)SO_(4)production during the daytime,while olefin ozone oxidation contributed up to 65%of total H_(2)SO_(4)production during the night-time.A sensitivity analysis of the H_(2)SO_(4)production parameters has revealed a high sensitivity to changes in sulfur dioxide,and a relatively high sensitivity to olefins with fast ozonolysis reaction rates and bimolecular reaction rates of resulting stabilized Criegee Intermediates.A high relative humidity promotes daytime H_(2)SO_(4)formation,but has an inhibiting effect during the night-time due to the different dominant reaction pathways.展开更多
Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of aerosols.In this study,we measured the hygroscopic growth factors(GF)of particles with dry diam...Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of aerosols.In this study,we measured the hygroscopic growth factors(GF)of particles with dry diameters of 40,80,150,and 200 nm during the wintertime in Nanjing.Both the GF-derived hygroscopicity parameter(κ_(gf))and ALWC increased with particle size,but displayed differing diurnal variations,withκ_(gf)peaking around the midday,while ALWC peaking in the early morning.Nitrate,ammonium and oxygenated organic aerosols(OOA)were found as the chemical components mostly strongly correlated with ALWC.A closure study suggests that during midday photo-oxidation and nighttime high ALWC periods,theκof organic aerosols(κ_(org))was underestimated when using previous parameterizations.Accordingly,we re-constructed parameterizations forκ_(org)and the oxidation level of organics for these periods,which indicates a higher hygroscopicity of photochemically formed OOA than the aqueous OOA,yet both being much higher than the generally assumed OOA hygroscopicity.Additionally,in a typical high ALWC episode,concurrently increased ALWC,nitrate,OOA as well as aerosol surface area and mass concentrations were observed under elevated ambient RH.This strongly indicates a coupled effect that the hygroscopic secondary aerosols,in particular nitratewith strong hygroscopicity,led to large increase in ALWC,which in turn synergistically boosted nitrate and OOA formation by heterogeneous/aqueous reactions.Such interaction may represent an important mechanism contributing to enhanced formation of secondary aerosols and rapid growth of fine particulate matter under relatively high RH conditions.展开更多
The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus...The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.展开更多
Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provi...Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provide valuable insights into the health status of an individual,accurate diagnosis,and efficient treatment strategies for diseases.Super-resolution microscopy(SRM)has recently emerged as a cutting-edge tool for the study of blood cells,providing numerous advantages over traditional methods for examining subcellular structures and proteins.In this paper,we focus on outlining the fundamental principles of various SRM techniques and their applications in both normal and diseased states of blood cells.Furthermore,future prospects of SRM techniques in the analysis of blood cells are also discussed.展开更多
Objective This study aimed to evaluate whether cardiac rehabilitation with a technology-assisted personalized exercise prescription is superior to traditional remote home-based rehabilitation in improving cardiorespir...Objective This study aimed to evaluate whether cardiac rehabilitation with a technology-assisted personalized exercise prescription is superior to traditional remote home-based rehabilitation in improving cardiorespiratory endurance and quality of life in postoperative patients.Methods From October 2022 to April 2024,62 patients who underwent percutaneous coronary intervention for coronary heart disease were recruited from a tertiary hospital in Beijing and randomly assigned to either an intervention group or a control group.After baseline assessments of cardiorespiratory endurance and exercise function,the intervention group received a digitalized personalized exercise prescription combined with remote monitoring rehabilitation.This included an exercise prescription delivered via a mobile application,weekly remote monitoring sessions with an exercise therapist to supervise prescription adherence,provide feedback based on real-time electrocardiographic data,and make personalized adjustments to the exercise prescription based on this information.The control group received an application-delivered exercise movement library and a wearable electrocardiogram device for self-monitoring of exercise intensity.Both groups underwent the 12-week intervention.Changes in maximal oxygen uptake and quality of life were evaluated at enrollment,as well as at 4 weeks,12 weeks,and 24 weeks after the intervention commenced.Results A total of 58 participants completed the study(the intervention group[n=30],the control group[n=28]).Twelve weeks after the interventions,the intervention group showed statistically improvements in VO2AT(Z=2.247,P=0.025),general health(Z=2.126,P=0.033)and social functioning(Z=3.349,P=0.001)compared to the control group.At 24 weeks of follow-up,the intervention group continued to exhibit statistically significant improvements in VO2AT(Z=2.017,P=0.044)and social functioning(Z=3.126,P=0.002).The exercise duration of patients in the intervention group during the exercise test was significantly prolonged at both 4 weeks(Z=−2.420,P=0.021),12 weeks(Z=−2.240,P=0.029)and 24weeks(Z=−2.300,P=0.025)showing statistically significant differences compared to the control group.Conclusions This study provides new evidence-based support for the practical effectiveness of nurses acting as supervisors of rehabilitation implementation and coordinators of multidisciplinary teams within a remote digital cardiac rehabilitation model,underscoring their significant value in the secondary prevention management system for cardiovascular diseases in the information era.展开更多
AIM: To investigate the relationship between contrastenhanced ultrasound(CEUS),basic fibroblast growth factor(b FGF),endothelin-1(ET-1),and hepatocellular carcinoma(HCC) recurrence after ablation. METHODS: A total of ...AIM: To investigate the relationship between contrastenhanced ultrasound(CEUS),basic fibroblast growth factor(b FGF),endothelin-1(ET-1),and hepatocellular carcinoma(HCC) recurrence after ablation. METHODS: A total of 51 HCC patients(38 males and 13 females) who received radiofrequency ablation in our hospital from June 2012 to July 2014 were enrolled in this study. The patients were divided into two groups: recurrence group and non-recurrence group. Routine abdominal examination was first performed in the horizontal position. Then the patients underwent CEUS and immunohistochemical staining before receiving radiofrequency ablation. All patients were followed-up every three months for one year.The results of CEUS and serum tumor marker levels were evaluated and combined together to estimate HCC recurrence and metastasis. Patients were divided into two groups: recurrence group and non-recurrence group. Quantitative parameters of CEUS and tumor expression levels of b FGF and ET-1 were compared between the two groups,respectively. Binary logistic regression analysis was used to analyze the relationship between CEUS quantitative parameters,expression levels of ET-1 and b FGF,and HCC recurrence after ablation. RESULTS: Based on the quantitative parameters of CEUS before patients received radiofrequency ablation,the levels of tumor rise time(t RT),tumor time to peak(t TTP),tumor peak intensity(t PI) and tumorparenchymal peak intensity(t-p PI) in the recurrence group were significantly lower than those in the nonrecurrence group(16.6 ± 6.1 vs 23.2 ± 7.0,P = 0.000; 41.2 ± 10.2 vs 59.6 ± 14.2,P = 0.000; 23.8 ± 6.7 vs 31.4 ± 6.4,P = 0.000; 7.1 ± 3.4 vs 14.6 ± 7.4,P = 0.000; respectively). The expression levels of b FGF in the recurrence group were significantly higher than those in the non-recurrence group(P < 0.05). Levels of t TTP showed a significant inverse correlation with the level of b FGF in tumors(r =-0.312,P = 0.037). The Binary logistic regression analysis results revealed that the levels of t RT,t TTP,t PI and the level of b FGF were associated with HCC recurrence after radiofrequency ablation(P < 0.05). CONCLUSION: CEUS is a noninvasive and effective method for evaluating the angiogenesis of HCC,and predicting its recurrence and prognosis.展开更多
In this study,the disease resistance gene PlWRKY65 was isolated from the leaves of Paeonia lactiflora and analyzed by bioinformatics methods,and the localization of the encoded protein was explored.Quantitative real-t...In this study,the disease resistance gene PlWRKY65 was isolated from the leaves of Paeonia lactiflora and analyzed by bioinformatics methods,and the localization of the encoded protein was explored.Quantitative real-time PCR(qRTPCR)was also used to explore the response of this gene to Alternaria tenuissima.The results showed that the gene sequence contained multiple cis-acting elements involved in the response to hormone signaling molecules belonging to the IIe subgroup of the WRKY family,and the encoded proteins were located in the nucleus.The PlWRKY65 gene has a positive regulatory effect on A.tenuissima infection.After silencing the PlWRKY65 gene via virus-induced gene silencing(VIGS),it was found that the gene-silenced plants were more sensitive to A.tenuissima infection than the wild plants,exhibiting more severe infection symptoms and different degrees of changes in the expression of the pathogenesis-related(PR)genes.In addition,we showed that the endogenous jasmonic acid(JA)content of P.lactiflora was increased in response to A.tenuissima infection,whereas the salicylic acid(SA)content decreased.After PlWRKY65 gene silencing,the levels of the two hormones changed accordingly,indicating that PlWRKY65,acting as a disease resistance-related transcriptional activator,exerts a regulatory effect on JA and SA signals.This study lays the foundation for functional research on WRKY genes in P.lactiflora and for the discovery of candidate disease resistance genes.展开更多
Based on Recursive Radial Basis Function(RRBF)neural network,the Reduced Order Model(ROM)of compressor cascade was established to meet the urgent demand of highly efficient prediction of unsteady aerodynamics performa...Based on Recursive Radial Basis Function(RRBF)neural network,the Reduced Order Model(ROM)of compressor cascade was established to meet the urgent demand of highly efficient prediction of unsteady aerodynamics performance of turbomachinery.One novel ROM called ASA-RRBF model based on Adaptive Simulated Annealing(ASA)algorithm was developed to enhance the generalization ability of the unsteady ROM.The ROM was verified by predicting the unsteady aerodynamics performance of a highly-loaded compressor cascade.The results show that the RRBF model has higher accuracy in identification of the dimensionless total pressure and dimensionless static pressure of compressor cascade under nonlinear and unsteady conditions,and the model behaves higher stability and computational efficiency.However,for the strong nonlinear characteristics of aerodynamic parameters,the RRBF model presents lower accuracy.Additionally,the RRBF model predicts with a large error in the identification of aerodynamic parameters under linear and unsteady conditions.For ASA-RRBF,by introducing a small-amplitude and highfrequency sinusoidal signal as validation sample,the width of the basis function of the RRBF model is optimized to improve the generalization ability of the ROM under linear unsteady conditions.Besides,this model improves the predicting accuracy of dimensionless static pressure which has strong nonlinear characteristics.The ASA-RRBF model has higher prediction accuracy than RRBF model without significantly increasing the total time consumption.This novel model can predict the linear hysteresis of dimensionless static pressure happened in the harmonic condition,but it cannot accurately predict the beat frequency of dimensionless total pressure.展开更多
Owing to their exceptional properties,high-entropy alloys(HEAs)and high-entropy materials have emerged as promising research areas and shown diverse applications.Here,the recent advances in the field are comprehensive...Owing to their exceptional properties,high-entropy alloys(HEAs)and high-entropy materials have emerged as promising research areas and shown diverse applications.Here,the recent advances in the field are comprehensively reviewed,organized into five sections.The first section introduces the background of HEAs,covering their definition,significance,application prospects,basic properties,design principles,and microstructure.The subsequent section focuses on cutting-edge high-entropy structural materials,highlighting developments such as nanostructured alloys,grain boundary engineering,eutectic systems,cryogenic alloys,thin films,micro-nano-lattice structures,additive manufacturing,high entropy metallic glasses,nano-precipitate strengthened alloys,composition modulation,alloy fibers,and refractory systems.In the following section,the emphasis shifts to functional materials,exploring HEAs as catalysts,magneto-caloric materials,corrosion-resistant alloys,radiation-resistant alloys,hydrogen storage systems,and materials for biomedicine.Additionally,the review encompasses functional high-entropy materials outside the realm of alloys,including thermoelectric,quantum dots,nanooxide catalysts,energy storage materials,negative thermal expansion ceramics,and high-entropy wave absorption materials.The paper concludes with an outlook,discussing future directions and potential growth areas in the field.Through this comprehensive review,researchers,engineers,and scientists may gain valuable insights into the recent progress and opportunities for further exploration in the exciting domains of high-entropy alloys and functional materials.展开更多
Previous study revealed that ferritin heavy chain-1(FTH1)could regulate ferritinophagy and affect intracellular Fe^(+)content in various tumors,while its N6-methyladenosine(m6A)RNA methylation was closely related the ...Previous study revealed that ferritin heavy chain-1(FTH1)could regulate ferritinophagy and affect intracellular Fe^(+)content in various tumors,while its N6-methyladenosine(m6A)RNA methylation was closely related the prognosis of ovarian cancer patients.However,little is known about the role of FTH1 m6A methylation in ovarian cancer(OC)and its possible action mechanisms.In this study we constructed FTH1 m6A methylation regulatory pathway(LncRNA CACNA1G-AS1/IGF2BP1)according to related bioinformatics analysis and research,through clinical sample detections we found that these pathway regulatory factors were significantly up-regulated in ovarian cancer tissues,and their expression levels were closely related to the malignant phenotype of ovarian cancer.In vitro cell experiments showed that LncRNA CACNA1G-AS1 could up-regulate FTH1 expression through IGF2BP1 axis,thus inhibited ferroptosis by regulating ferritinophagy,and finally promoted proliferation and migration in ovarian cancer cells.Tumor-bearing mice studies showed that the knock-down of LncRNA CACNA1G-AS1 could inhibited the tumorigenesis of ovarian cancer cells in vivo condition.Our results demonstrated that LncRNA CACNA1G-AS1 could promote the malignant phenotypes of ovarian cancer cells through FTH1-IGF2BP1 regulated ferroptosis.展开更多
The effects of Sm_(2) O_(3) as an additive on the densification of a pre-synthesized magnesia-rich spinel were investigated.The sintering behavior of the material was characterized by analyzing its dilatometric charac...The effects of Sm_(2) O_(3) as an additive on the densification of a pre-synthesized magnesia-rich spinel were investigated.The sintering behavior of the material was characterized by analyzing its dilatometric characteristics,linear shrinkage,bulk density,apparent porosity,phase structure,and micro structure.Moreover,the cold modulus of rupture(CMOR) and microhardness of the spinel were measured.The results show that samarium oxide reacts with the spinel to form SmAlO_(3)(a rare-earth aluminate) to improve the sintering performance and mechanical properties of the spinel. The formation of magnesite phases decreases the rupture strength of the spinel.However,this MgO phase is inlaid in spinel grains boundary,has a pinning effect which can improve the sinterability of the spinel.展开更多
The design and fabrication of electromagnetic interference shielding films with a novel structure to eliminate undesirable electromagnetic pollution is an important research direction.However,it is still a challenge t...The design and fabrication of electromagnetic interference shielding films with a novel structure to eliminate undesirable electromagnetic pollution is an important research direction.However,it is still a challenge to combine and organize nanofillers in different dimensions into the structured network in polymer-based electromagnetic interference(EMI)shielding composites.In this work,a sandwich struc-ture polyimide(PI)composite film with alternative 2D-MXene network and 1D-Silver nanowires(Ag NWs)network was prepared through the“electrospinning-immersion-hot pressing”method.With the increase of Ag NWs content,the EMI shielding effectiveness(SE)gradually increases while maintaining good flexibility and mechanical robustness.The EMI SE and the tensile strength of 150μm thick sand-wich composite film can reach up to 79.54 dB and 39.82 MPa,respectively.The prepared flexible and robust PI composite film with a sandwich structure has high EMI SE with less metal content,which can provide guidelines for the development of high-performance EMI polymeric films with potentials in wearable devices and equipment.展开更多
With the purpose of studying the influence of Nd on the alloy structure and castability of ZM6, under the fixed content of Zn and Zr, this paper observes and analyzes the microstructure morphology of ZM6 alloy fractur...With the purpose of studying the influence of Nd on the alloy structure and castability of ZM6, under the fixed content of Zn and Zr, this paper observes and analyzes the microstructure morphology of ZM6 alloy fracture with dif- ferent Nd content by the means of uniaxial tension experiment and scanning electron microscope （SEM） observation. The search results indicate that the structure of ZM6 alloy after added Nd can be refined to some extent, while it has no obvious influence on the grain structure and dimension of as- ast ZM6 alloy. Through increasing the ratio between Nd and Zn, it turns out that Nd and Zn reduces their own solid solu- bility by each other in α-Mg, and meanwhile, they gather toward the grain boundary, which is beneficial to refine the structure of ZM6 alloy ingot and enables the grain dimension of ZM6 alloy to reach the minimum when the Nd content is 2.5 %. On the basis of the minimization of the grain dimen- sion, the tensile property of ZM6 alloy improves with the Nd content. Thus, it provides theoretical guidance and technical support for the improvement of ZM6 alloy structure.展开更多
Wf/Cu82Al10Fe4Ni4composite was fabricated by means of infiltration casting. By the microstructure observation of the composite with the aid of scanning electron microscopy（SEM） and transmission electron microscopy（...Wf/Cu82Al10Fe4Ni4composite was fabricated by means of infiltration casting. By the microstructure observation of the composite with the aid of scanning electron microscopy（SEM） and transmission electron microscopy（TEM）, it can be found that there are（Fe, Ni）,AlFe, Al3 Ni, and Cu3 Al precipitated phases existing in the matrix alloy. By two-stage light gas gun, Wf/Cu82Al10-Fe4Ni4composite hypervelocity projectile into concrete target test with the speed of 2.2 kmás-1is finished. By microstructure observation, it can be found that the failure mode of Wf/Cu82Al10Fe4Ni4composite projectile during penetration is the rapid peeling of tungsten fibers from the projectile, which makes the projectile display good selfsharpening property. Meanwhile, it can be found that microstructure morphology change of Wf/Cu82Al10Fe4Ni4composite occurs after hypervelocity impact. The density of dislocations around the large-dimensional（Fe, Ni）,AlFe, Al3 Ni, and Cu3 Al precipitated phases in the matrix alloy rises sharply. At the same time, there are largedimensional deformed twins existing in local regions and stacking faults existing inside the twins.展开更多
基金Supported by the Foundation of Health Commission of Hubei Province,No.WJ2019H053Natural Science Foundation of Hubei Province,No.2023AFB169+1 种基金Foundation of Health Commission of Hubei Province,No.ZY2021Q019Open Fund Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells,Taihe Hospital,No.2024SCOF008.
文摘BACKGROUND Large number of decompensated liver cirrhosis patients in China have been diagnosed with hepatitis B virus(HBV).Human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)can possibly cure decompensated liver cirrhosis because of their self-renewal and multidirectional differentiation potential.AIM To explore the safety and effect of treating liver cirrhosis with HBV by hUC-MSCs.METHODS Twenty-four participants were recruited,divided into 3 groups,and injected with different amounts of hUC-MSCs via the peripheral vein.Therapy was administered 3 times.A 24-week follow-up examination of each patient’s liver function,coagulation function,general condition,and immune system was performed.Adverse events were also recorded.A 2-year survival assessment was subsequently performed.RESULTS Infusion therapy rapidly improved liver function.Serum albumin transiently increased on days 57 and 85 but returned to baseline by day 169,while prothrombin time activity demonstrated sustained improvement from day 29 through day 169.Interleukin-8 levels decreased persistently throughout treatment.All dosage groups achieved 100%6-month survival;2-year survival rates were 66.7%(low-dose),100%(medium-dose),and 87.5%(high-dose).The interaction between dosage and efficacy was weak.Notably,the improvement in liver function was statistically significant and sustained for almost 3 months,suggesting clinically meaningful therapeutic durability.CONCLUSION hUC-MSCs can be considered a safe treatment for patients with decompensated liver cirrhosis associated with HBV.However,larger-scale randomized controlled trials are needed to prove its therapeutic effect.
文摘In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong” with RT-PCR and RACE methods and named as RrGlu. The full-length cDNA is 1380 bp with an open reading frame of 1041 bp, encoding 346 amino acids. The derived protein has a molecular weight of 37.85 kD, a calculated pI of 9.12, a pfam00332 conserved domain at position 36 - 345, and belongs to glycosyl hydrolase family 17. The derived protein is a hydrophilic protein secreted into the vacuole. There is a signal peptide cleavage site at position 34 - 35, a transmembrane domain at position 13 - 32, six Ser phosphorylation sites, three Thr phosphorylation sites, three Tyr phosphorylation sites, one N-glycosylation site, and five O-glycosylation sites. There are 31.50% α-helixes, 30.92% random coil, 25.14% extended peptide chain, and 12.43% β-corner structure. This protein and the Glu protein from eight other species, including Prunus persica, share a sequence homology of greater than 72%;all of the proteins contain a pfam00332 conserved domain and a β-1,3-glucanase active center sequence (LIVM)-X-(LIVMFYW)3-(STAG)-E-(ST)-G-W-P-(ST)-X-G. Furthermore, their phylogenetic relationships are consistent with their traditional classifications. These results were meaningful to reveal the molecular mechanism of R. rugosa pollination incompatibility and improve the theory and techniques of breeding ornamental R. rugosa.
文摘The geographical condition of Qingdao, China is relatively special;the transport of various inland pollutants, the emissions of marine aerosol and local pollutants will have an impact on the changes of atmospheric aerosol concentration. By using the stability classification method, trajectory clustering analysis and the NOAA HYSPLIT model, the seasonal distribution characteristics of atmospheric inhalable particulate matter concentration in Qingdao, China and its relationship with meteorological conditions, mixed layer height, and the seasonal characteristics of Qingdao pollutant transport were analyzed. The results show that the variation trends of PM2.5 and PM10 were about the same, and there are obvious seasonal differences, which are high in winter and spring, and low in summer and autumn. The concentration of inhalable particulate matter has a negative correlation with temperature, wind speed and relative humidity. The concentration of inhalable particulate matter is distinct in different relative humidity ranges. When the wind speed is less than 3 - 4 m/s, there are more inhalable particles, while the mass concentration shows obvious reduction with the wind speed more than 4 m/s. There is a significant negative correlation between the mass concentration of pollutants and the daily maximum mixed layer height. The larger the concentration of pollutants, the smaller the thickness of the daily largest mixed layer. Conversely, the smaller the mass concentration of pollutants, the larger the thickness of the daily largest mixed layer. The pollutant transport in Qingdao has obvious seasonal characteristics. The air mass in spring, autumn and winter is mainly medium-long distance transport from Mongolia and southern Russia, and medium-short distance transport from Inner Mongolia and northeast of China. The source of air masses in summer is mainly transported from the eastern and sea areas.
文摘In many wild species, seeds are dormancy at maturity and will not germinate even under favorable environment conditions. Dormancy is a complex trail that is determined by many factors. Some studies have shown that cold stratification and the application of gibberellic acid (GA) can break seed dormancy and promote seed germination. The present study investigated the causes of plant dormancy and the effect of cold stratification and different concentrations of exogenous GA<sub>3</sub> in regulating Cephalotaxus sinensis seed germination. Results showed that C. Sinensis seeds have good water permeability, which suggested that seed coats were not the main cause that inhibited the seed germination. There were germination inhibitions in all parts of seeds, and the order of inhibitory effect was: testa < endosperm (embryo), which indicated that existence of germination inhibitions was the main reason causing seed dormancy. Endogenous GAs and IAA (indole-3-acetic acid) content increased, while ABA (abscisic acid) content decreased over the experiments. ZR (zeatin riboside) content decreased in the early phase of cold stratification, but rebounded by the end of the experimental period. The changes of endogenous hormone indicated that GA, IAA and ZR played a positive role in seed germination, whereas ABA was associated with seed dormancy. Besides, the relative ratio of GA/ABA, IAA/ABA and ZR/ABA may play a more important role than their absolute level during the seed development.
基金supported by the National Natural Science Foundation of China(Nos.41975172,42275116,and 41730106).
文摘This study has employed the master chemical mechanism(MCM)to investigate the influence of the ozone oxidation pathways in the atmospheric formation of H_(2)SO_(4)from shortchain olefins in industrialized areas.In-situ H_(2)SO_(4)formation data were obtained using a high-resolution chemical ionization time-of-flight mass spectrometer,and the simulated H_(2)SO_(4)concentrations calculated using updated parameters for the MCM model exhibited good agreementwith observations.In the simulation analysis of different reaction pathways involved in H_(2)SO_(4)formation,hydroxyl radicals were found to dominate H_(2)SO_(4)production during the daytime,while olefin ozone oxidation contributed up to 65%of total H_(2)SO_(4)production during the night-time.A sensitivity analysis of the H_(2)SO_(4)production parameters has revealed a high sensitivity to changes in sulfur dioxide,and a relatively high sensitivity to olefins with fast ozonolysis reaction rates and bimolecular reaction rates of resulting stabilized Criegee Intermediates.A high relative humidity promotes daytime H_(2)SO_(4)formation,but has an inhibiting effect during the night-time due to the different dominant reaction pathways.
基金supported by the National Natural Science Foundation of China(Nos.42275116 and 41975172).
文摘Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of aerosols.In this study,we measured the hygroscopic growth factors(GF)of particles with dry diameters of 40,80,150,and 200 nm during the wintertime in Nanjing.Both the GF-derived hygroscopicity parameter(κ_(gf))and ALWC increased with particle size,but displayed differing diurnal variations,withκ_(gf)peaking around the midday,while ALWC peaking in the early morning.Nitrate,ammonium and oxygenated organic aerosols(OOA)were found as the chemical components mostly strongly correlated with ALWC.A closure study suggests that during midday photo-oxidation and nighttime high ALWC periods,theκof organic aerosols(κ_(org))was underestimated when using previous parameterizations.Accordingly,we re-constructed parameterizations forκ_(org)and the oxidation level of organics for these periods,which indicates a higher hygroscopicity of photochemically formed OOA than the aqueous OOA,yet both being much higher than the generally assumed OOA hygroscopicity.Additionally,in a typical high ALWC episode,concurrently increased ALWC,nitrate,OOA as well as aerosol surface area and mass concentrations were observed under elevated ambient RH.This strongly indicates a coupled effect that the hygroscopic secondary aerosols,in particular nitratewith strong hygroscopicity,led to large increase in ALWC,which in turn synergistically boosted nitrate and OOA formation by heterogeneous/aqueous reactions.Such interaction may represent an important mechanism contributing to enhanced formation of secondary aerosols and rapid growth of fine particulate matter under relatively high RH conditions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12033007,61801458,12103058,12203058,12074309,and 61875205)the Key Project of Frontier Science Research of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH007)+2 种基金the Strategic Priority Research Program of CAS(Grant No.XDC07020200)the Youth Innovation Promotion Association,CAS(Grant Nos.2021408,2022413,and 2023425)the Research on Highly Sensitive Long-Wave Receiver Based on Rydberg Atoms(Grant No.1P2024000059)。
文摘The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.
基金supported by the following grants:National Key R&D Program of China(Grant no.2022YFC3401100)National Natural Science Foundation of China(Grant nos.32271428,92054110,32201132 and 31600692).
文摘Blood cells are the most integral part of the body,which are made up of erythrocytes,platelets and white blood cells.The examination of subcellular structures and proteins within blood cells at the nanoscale can provide valuable insights into the health status of an individual,accurate diagnosis,and efficient treatment strategies for diseases.Super-resolution microscopy(SRM)has recently emerged as a cutting-edge tool for the study of blood cells,providing numerous advantages over traditional methods for examining subcellular structures and proteins.In this paper,we focus on outlining the fundamental principles of various SRM techniques and their applications in both normal and diseased states of blood cells.Furthermore,future prospects of SRM techniques in the analysis of blood cells are also discussed.
文摘Objective This study aimed to evaluate whether cardiac rehabilitation with a technology-assisted personalized exercise prescription is superior to traditional remote home-based rehabilitation in improving cardiorespiratory endurance and quality of life in postoperative patients.Methods From October 2022 to April 2024,62 patients who underwent percutaneous coronary intervention for coronary heart disease were recruited from a tertiary hospital in Beijing and randomly assigned to either an intervention group or a control group.After baseline assessments of cardiorespiratory endurance and exercise function,the intervention group received a digitalized personalized exercise prescription combined with remote monitoring rehabilitation.This included an exercise prescription delivered via a mobile application,weekly remote monitoring sessions with an exercise therapist to supervise prescription adherence,provide feedback based on real-time electrocardiographic data,and make personalized adjustments to the exercise prescription based on this information.The control group received an application-delivered exercise movement library and a wearable electrocardiogram device for self-monitoring of exercise intensity.Both groups underwent the 12-week intervention.Changes in maximal oxygen uptake and quality of life were evaluated at enrollment,as well as at 4 weeks,12 weeks,and 24 weeks after the intervention commenced.Results A total of 58 participants completed the study(the intervention group[n=30],the control group[n=28]).Twelve weeks after the interventions,the intervention group showed statistically improvements in VO2AT(Z=2.247,P=0.025),general health(Z=2.126,P=0.033)and social functioning(Z=3.349,P=0.001)compared to the control group.At 24 weeks of follow-up,the intervention group continued to exhibit statistically significant improvements in VO2AT(Z=2.017,P=0.044)and social functioning(Z=3.126,P=0.002).The exercise duration of patients in the intervention group during the exercise test was significantly prolonged at both 4 weeks(Z=−2.420,P=0.021),12 weeks(Z=−2.240,P=0.029)and 24weeks(Z=−2.300,P=0.025)showing statistically significant differences compared to the control group.Conclusions This study provides new evidence-based support for the practical effectiveness of nurses acting as supervisors of rehabilitation implementation and coordinators of multidisciplinary teams within a remote digital cardiac rehabilitation model,underscoring their significant value in the secondary prevention management system for cardiovascular diseases in the information era.
基金supported by the High Technology Research and Development Program of Jilin(20130204021GX)the Specialized Research Fund for Graduate Course Identification System Program(Jilin University)of China(450060523183)+2 种基金the National Natural Science Foundation of China(61520106008,U1564207,61503149)the Education Department of Jilin Province of China(2016430)the Graduate Innovation Fund of Jilin University(2016030)
文摘AIM: To investigate the relationship between contrastenhanced ultrasound(CEUS),basic fibroblast growth factor(b FGF),endothelin-1(ET-1),and hepatocellular carcinoma(HCC) recurrence after ablation. METHODS: A total of 51 HCC patients(38 males and 13 females) who received radiofrequency ablation in our hospital from June 2012 to July 2014 were enrolled in this study. The patients were divided into two groups: recurrence group and non-recurrence group. Routine abdominal examination was first performed in the horizontal position. Then the patients underwent CEUS and immunohistochemical staining before receiving radiofrequency ablation. All patients were followed-up every three months for one year.The results of CEUS and serum tumor marker levels were evaluated and combined together to estimate HCC recurrence and metastasis. Patients were divided into two groups: recurrence group and non-recurrence group. Quantitative parameters of CEUS and tumor expression levels of b FGF and ET-1 were compared between the two groups,respectively. Binary logistic regression analysis was used to analyze the relationship between CEUS quantitative parameters,expression levels of ET-1 and b FGF,and HCC recurrence after ablation. RESULTS: Based on the quantitative parameters of CEUS before patients received radiofrequency ablation,the levels of tumor rise time(t RT),tumor time to peak(t TTP),tumor peak intensity(t PI) and tumorparenchymal peak intensity(t-p PI) in the recurrence group were significantly lower than those in the nonrecurrence group(16.6 ± 6.1 vs 23.2 ± 7.0,P = 0.000; 41.2 ± 10.2 vs 59.6 ± 14.2,P = 0.000; 23.8 ± 6.7 vs 31.4 ± 6.4,P = 0.000; 7.1 ± 3.4 vs 14.6 ± 7.4,P = 0.000; respectively). The expression levels of b FGF in the recurrence group were significantly higher than those in the non-recurrence group(P < 0.05). Levels of t TTP showed a significant inverse correlation with the level of b FGF in tumors(r =-0.312,P = 0.037). The Binary logistic regression analysis results revealed that the levels of t RT,t TTP,t PI and the level of b FGF were associated with HCC recurrence after radiofrequency ablation(P < 0.05). CONCLUSION: CEUS is a noninvasive and effective method for evaluating the angiogenesis of HCC,and predicting its recurrence and prognosis.
基金funded by the Shandong Provincial Agricultural Elite Varieties Project(2019 LZGC018),China.
文摘In this study,the disease resistance gene PlWRKY65 was isolated from the leaves of Paeonia lactiflora and analyzed by bioinformatics methods,and the localization of the encoded protein was explored.Quantitative real-time PCR(qRTPCR)was also used to explore the response of this gene to Alternaria tenuissima.The results showed that the gene sequence contained multiple cis-acting elements involved in the response to hormone signaling molecules belonging to the IIe subgroup of the WRKY family,and the encoded proteins were located in the nucleus.The PlWRKY65 gene has a positive regulatory effect on A.tenuissima infection.After silencing the PlWRKY65 gene via virus-induced gene silencing(VIGS),it was found that the gene-silenced plants were more sensitive to A.tenuissima infection than the wild plants,exhibiting more severe infection symptoms and different degrees of changes in the expression of the pathogenesis-related(PR)genes.In addition,we showed that the endogenous jasmonic acid(JA)content of P.lactiflora was increased in response to A.tenuissima infection,whereas the salicylic acid(SA)content decreased.After PlWRKY65 gene silencing,the levels of the two hormones changed accordingly,indicating that PlWRKY65,acting as a disease resistance-related transcriptional activator,exerts a regulatory effect on JA and SA signals.This study lays the foundation for functional research on WRKY genes in P.lactiflora and for the discovery of candidate disease resistance genes.
基金co-National Science and Technology Major Project(No.2017-II-0009-0023)Innovation Guidance Support Project for Taicang Top Research Institutes(No.TC2019DYDS09)。
文摘Based on Recursive Radial Basis Function(RRBF)neural network,the Reduced Order Model(ROM)of compressor cascade was established to meet the urgent demand of highly efficient prediction of unsteady aerodynamics performance of turbomachinery.One novel ROM called ASA-RRBF model based on Adaptive Simulated Annealing(ASA)algorithm was developed to enhance the generalization ability of the unsteady ROM.The ROM was verified by predicting the unsteady aerodynamics performance of a highly-loaded compressor cascade.The results show that the RRBF model has higher accuracy in identification of the dimensionless total pressure and dimensionless static pressure of compressor cascade under nonlinear and unsteady conditions,and the model behaves higher stability and computational efficiency.However,for the strong nonlinear characteristics of aerodynamic parameters,the RRBF model presents lower accuracy.Additionally,the RRBF model predicts with a large error in the identification of aerodynamic parameters under linear and unsteady conditions.For ASA-RRBF,by introducing a small-amplitude and highfrequency sinusoidal signal as validation sample,the width of the basis function of the RRBF model is optimized to improve the generalization ability of the ROM under linear unsteady conditions.Besides,this model improves the predicting accuracy of dimensionless static pressure which has strong nonlinear characteristics.The ASA-RRBF model has higher prediction accuracy than RRBF model without significantly increasing the total time consumption.This novel model can predict the linear hysteresis of dimensionless static pressure happened in the harmonic condition,but it cannot accurately predict the beat frequency of dimensionless total pressure.
基金financially supported by the National Key R&D Program of China(No.2021YFB3802800)the National Natural Science Foundation of China(Nos.52222104,12261160364,51871120,51520105001,22275089,52071157,52231005,52201174,52171165,52261033,52371155,51801128,52171219,U20A20278,52371106,22071221,52122408,52201190,22075014,52272040,62222405,22125602,and 52301052)+11 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20200019,BK20220858 and BK20231458)support by the open research fund of Songshan Lake Materials Laboratory(No.2022SLABFN19)support by Guangdong Basic and Applied Basic Research Foundation(No2024B1515020010)support by Shanxi Province Youth Innovation Team Project(No.22JP042)support by the National Science Fund for Distinguished Young Scholars of China(No.52325102)support by the Large Scientific Facility Open Subject of Songshan Lake,Dongguan,Guangdongsupport by the research institute for Advanced Manufacturing Fund(No.P0046108)support by the Hong Kong RGC general research fund(No.11200623)and CRF project C7074-23Gfinancial support from the Australian Research CouncilHBIS-UQ Innovation Centre for Sustainable Steel projectthe QUT Capacity Building Professor Programsupport by the Fundamental Research Funds for the Central Universities(No.30923010211)。
文摘Owing to their exceptional properties,high-entropy alloys(HEAs)and high-entropy materials have emerged as promising research areas and shown diverse applications.Here,the recent advances in the field are comprehensively reviewed,organized into five sections.The first section introduces the background of HEAs,covering their definition,significance,application prospects,basic properties,design principles,and microstructure.The subsequent section focuses on cutting-edge high-entropy structural materials,highlighting developments such as nanostructured alloys,grain boundary engineering,eutectic systems,cryogenic alloys,thin films,micro-nano-lattice structures,additive manufacturing,high entropy metallic glasses,nano-precipitate strengthened alloys,composition modulation,alloy fibers,and refractory systems.In the following section,the emphasis shifts to functional materials,exploring HEAs as catalysts,magneto-caloric materials,corrosion-resistant alloys,radiation-resistant alloys,hydrogen storage systems,and materials for biomedicine.Additionally,the review encompasses functional high-entropy materials outside the realm of alloys,including thermoelectric,quantum dots,nanooxide catalysts,energy storage materials,negative thermal expansion ceramics,and high-entropy wave absorption materials.The paper concludes with an outlook,discussing future directions and potential growth areas in the field.Through this comprehensive review,researchers,engineers,and scientists may gain valuable insights into the recent progress and opportunities for further exploration in the exciting domains of high-entropy alloys and functional materials.
基金Suzhou Youth Project of Promoting Health through Science and Education,Grant ID:KJXW2022010.
文摘Previous study revealed that ferritin heavy chain-1(FTH1)could regulate ferritinophagy and affect intracellular Fe^(+)content in various tumors,while its N6-methyladenosine(m6A)RNA methylation was closely related the prognosis of ovarian cancer patients.However,little is known about the role of FTH1 m6A methylation in ovarian cancer(OC)and its possible action mechanisms.In this study we constructed FTH1 m6A methylation regulatory pathway(LncRNA CACNA1G-AS1/IGF2BP1)according to related bioinformatics analysis and research,through clinical sample detections we found that these pathway regulatory factors were significantly up-regulated in ovarian cancer tissues,and their expression levels were closely related to the malignant phenotype of ovarian cancer.In vitro cell experiments showed that LncRNA CACNA1G-AS1 could up-regulate FTH1 expression through IGF2BP1 axis,thus inhibited ferroptosis by regulating ferritinophagy,and finally promoted proliferation and migration in ovarian cancer cells.Tumor-bearing mice studies showed that the knock-down of LncRNA CACNA1G-AS1 could inhibited the tumorigenesis of ovarian cancer cells in vivo condition.Our results demonstrated that LncRNA CACNA1G-AS1 could promote the malignant phenotypes of ovarian cancer cells through FTH1-IGF2BP1 regulated ferroptosis.
基金Project supported by the National Natural Science Foundation of China (U20A20239,51672195,51474166)。
文摘The effects of Sm_(2) O_(3) as an additive on the densification of a pre-synthesized magnesia-rich spinel were investigated.The sintering behavior of the material was characterized by analyzing its dilatometric characteristics,linear shrinkage,bulk density,apparent porosity,phase structure,and micro structure.Moreover,the cold modulus of rupture(CMOR) and microhardness of the spinel were measured.The results show that samarium oxide reacts with the spinel to form SmAlO_(3)(a rare-earth aluminate) to improve the sintering performance and mechanical properties of the spinel. The formation of magnesite phases decreases the rupture strength of the spinel.However,this MgO phase is inlaid in spinel grains boundary,has a pinning effect which can improve the sinterability of the spinel.
基金supported by National Natural Science Foundation of China(61520106008,U1564207,61503149)High Technology Research and Development Program of Jilin(20130204021GX)+1 种基金Specialized Research Fund for Graduate Course Identification System Program(Jilin University)of China(450060523183)Graduate Innovation Fund of Jilin University(2015148)
基金the Fund of Natural Science Founda-tion of Shaanxi Provincial(No.2021JQ-111)the Fund of Basic and Applied Fundamental Research of Guangdong Provincial(No.2020A1515110861).
文摘The design and fabrication of electromagnetic interference shielding films with a novel structure to eliminate undesirable electromagnetic pollution is an important research direction.However,it is still a challenge to combine and organize nanofillers in different dimensions into the structured network in polymer-based electromagnetic interference(EMI)shielding composites.In this work,a sandwich struc-ture polyimide(PI)composite film with alternative 2D-MXene network and 1D-Silver nanowires(Ag NWs)network was prepared through the“electrospinning-immersion-hot pressing”method.With the increase of Ag NWs content,the EMI shielding effectiveness(SE)gradually increases while maintaining good flexibility and mechanical robustness.The EMI SE and the tensile strength of 150μm thick sand-wich composite film can reach up to 79.54 dB and 39.82 MPa,respectively.The prepared flexible and robust PI composite film with a sandwich structure has high EMI SE with less metal content,which can provide guidelines for the development of high-performance EMI polymeric films with potentials in wearable devices and equipment.
基金This project was financially supported by the Fundamental Research Funds for the Central Universities （No.DLI 2C B05）, the National Natural Science Foundation of China （Nos.31170517 and 31070500）, the Research Fund for the Doctoral Program of Higher Education of China （No.20112303120001）, and the Natural Science Foundation of Heilongjiang Province of China （No.E201128）.
文摘With the purpose of studying the influence of Nd on the alloy structure and castability of ZM6, under the fixed content of Zn and Zr, this paper observes and analyzes the microstructure morphology of ZM6 alloy fracture with dif- ferent Nd content by the means of uniaxial tension experiment and scanning electron microscope （SEM） observation. The search results indicate that the structure of ZM6 alloy after added Nd can be refined to some extent, while it has no obvious influence on the grain structure and dimension of as- ast ZM6 alloy. Through increasing the ratio between Nd and Zn, it turns out that Nd and Zn reduces their own solid solu- bility by each other in α-Mg, and meanwhile, they gather toward the grain boundary, which is beneficial to refine the structure of ZM6 alloy ingot and enables the grain dimension of ZM6 alloy to reach the minimum when the Nd content is 2.5 %. On the basis of the minimization of the grain dimen- sion, the tensile property of ZM6 alloy improves with the Nd content. Thus, it provides theoretical guidance and technical support for the improvement of ZM6 alloy structure.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. DL12BB04)the National Natural Science Foundation of China (Nos. 31200434 and 31370566)
文摘Wf/Cu82Al10Fe4Ni4composite was fabricated by means of infiltration casting. By the microstructure observation of the composite with the aid of scanning electron microscopy（SEM） and transmission electron microscopy（TEM）, it can be found that there are（Fe, Ni）,AlFe, Al3 Ni, and Cu3 Al precipitated phases existing in the matrix alloy. By two-stage light gas gun, Wf/Cu82Al10-Fe4Ni4composite hypervelocity projectile into concrete target test with the speed of 2.2 kmás-1is finished. By microstructure observation, it can be found that the failure mode of Wf/Cu82Al10Fe4Ni4composite projectile during penetration is the rapid peeling of tungsten fibers from the projectile, which makes the projectile display good selfsharpening property. Meanwhile, it can be found that microstructure morphology change of Wf/Cu82Al10Fe4Ni4composite occurs after hypervelocity impact. The density of dislocations around the large-dimensional（Fe, Ni）,AlFe, Al3 Ni, and Cu3 Al precipitated phases in the matrix alloy rises sharply. At the same time, there are largedimensional deformed twins existing in local regions and stacking faults existing inside the twins.
