Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biot...Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.展开更多
When a perpendicular magnetic field penetrates a thin slab of a type-Ⅱ superconductor it produces vortices,with one vortex per flux quantum,h/2e.The vortices interact repulsively and form an ordered array(Abrikosov l...When a perpendicular magnetic field penetrates a thin slab of a type-Ⅱ superconductor it produces vortices,with one vortex per flux quantum,h/2e.The vortices interact repulsively and form an ordered array(Abrikosov lattice)in clean systems,while strong disorder changes the lattice into a vortex glass.The collective vortex dynamics is extremely vulnerable to external perturbations.Consequently,although of great importance,experimental observation is limited.Here we investigate type-Ⅱ superconducting films(PdBi_(2)and NbSe_(2))with surface acoustic waves(SAWs)at mK temperature.When sweeping the magnetic field at an extremely slow rate,we observe a series of spikes in the attenuation and velocity of the SAW,on average separated in field by approximately Hc1.We propose the following scenario:The vortex-free region at the edges of the film produces an edge barrier across which the vortices can enter or leave.When the applied field changes,the induced supercurrents flowing along this edge region lowers this barrier until there is an instability.At that point,vortices avalanche into(or out of)the bulk and change the vortex crystal,suggested by the sharp jump in each such spike.The vortices then gradually relax to a new stable pinned configuration,leading to a~30 s relaxation after the jump.Our observation enriches the limited experimental evidence on the important topic of real-time vortex dynamics in superconductors.展开更多
This study investigated the effect of konjac glucomannan(KGM)on the flotation separation of calcite and scheelite.Micro-flotation tests showed that under the action of 50 mg/L KGM,the floatability of calcite notably d...This study investigated the effect of konjac glucomannan(KGM)on the flotation separation of calcite and scheelite.Micro-flotation tests showed that under the action of 50 mg/L KGM,the floatability of calcite notably decreased,while the impact on scheelite was negligible,resulting in a recovery difference of 82.53%.Fourier transform infrared(FTIR)spectroscopy and atomic force micro-scopy(AFM)analyses indicated the selective adsorption of KGM on the calcite surface.Test results of the zeta potential and UV-visible absorption spectroscopy revealed that KGM prevented the adsorption of sodium oleate on the calcite surface.X-ray photoelectron spec-troscopy(XPS)analysis further confirmed the chemical adsorption of KGM on the calcite surface and the formation of Ca(OH)_(2).The density functional theory(DFT)simulation results were consistent with the flotation tests,demonstrating the strong adsorption perform-ance of KGM on the calcite surface.This study offers a pathway for highly sustainable and cost-effective mineral processing by utilizing the unique properties of biopolymers such as KGM to separate valuable minerals from gangue minerals.展开更多
Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the fron...Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the frontiers and key areas of grassland degradation research has not been achieved due to the limitations of traditional scientometrics methods.The present synthesis of information employed BERTopic,an advanced natural language processing tool,to analyze the extensive ecological literature on grassland degradation.We compiled a dataset of 4,504 publications from the Web of Science core collection database and used it to evaluate the geographic distribution and temporal evolution of different grassland types and available knowledge on the subject.Our analysis identified key topics in the global grassland degradation research domain,including the effects of grassland degradation on ecosystem functions,grassland ecological restoration and biodiversity conservation,erosion processes and hydrological models in grasslands,and others.The BERTopic analysis significantly outperforms traditional methods in identifying complex and evolving topics in large datasets of literature.Compared to traditional scientometrics analysis,BERTopic provides a more comprehensive perspective on the research areas,revealing not only popular topics but also emerging research areas that traditional methods may overlook,although scientometrics offers more specificity and detail.Therefore,we argue for the simultaneous use of both approaches to achieve more systematic and comprehensive assessments of specific research areas.This study represents an emerging application of BERTopic algorithms in ecological research,particularly in the critical research focused on global grassland degradation.It also highlights the need for integrating advanced computational methods in ecological research in this era of data explosion.Tools like the BERTopic algorithm are essential for enhancing our understanding of complex environmental problems,and it marks an important stride towards more sophisticated,data-driven analysis in ecology.展开更多
Molecular dynamics(MD)simulation is employed to investigate the deformation behavior under various loading paths and strain rates of nanocrystalline magnesium(NC Mg)with[0001]texture.Atomic-scale structural evolution ...Molecular dynamics(MD)simulation is employed to investigate the deformation behavior under various loading paths and strain rates of nanocrystalline magnesium(NC Mg)with[0001]texture.Atomic-scale structural evolution of NC Mg was performed under uniaxial and biaxial loadings.In tension process,compression twins and basal slip dominate,while the compression process is dominated by tension twins.The activation mechanism of twinning is highly sensitive to the loading path and grain orientation.Meanwhile,the effect of strain rate on the structural evolution of NC Mg was investigated.It is found that the effect of strain rate on the plastic deformation of NC Mg is reflected through the plasticity delays and the way to release the stress.As the strain rate decreases,the plastic deformation mechanism gradually changes from intragranular to grain boundary.Some significant potential deformation mechanisms in the loading process were studied.It is observed that{1121}twins nucleated inside the grains,and the thickening process is completed by basal〈a〉slip of the twin boundary.The strain compatibility between twins is automatically optimized with loading.Moreover,the detwinning mechanism caused by the interaction between twins and basal stacking faults is clarified.展开更多
The fracture behavior of natural fracture in the geological reservoir subjected to filling property,affects the crack initiation and propagation under stress perturbation.Partial filling flaws were intermediate betwee...The fracture behavior of natural fracture in the geological reservoir subjected to filling property,affects the crack initiation and propagation under stress perturbation.Partial filling flaws were intermediate between open fractures and filled fractures,the fracture response may be worth exploring.In this work,the effect of the filling property of sandstone with partial filling flaws on the fracture behavior was systematically investigated based on three-point bending tests and the numerical approach of discrete element method(DEM).In the laboratory,semi-circular three-point bending tests were carried out with partial filling flaws of various filling strengths.Based on this,numerical simulations were used to further investigate the effect of the filling ratio and the inclination of the partial filling flaw on the mechanical and fracture responses,and the effect of the partial filling flaw under mixed-mode loading on the fracture mechanism was elucidated coupled with acoustic emission(AE)characteristics.The obtained results showed that the increase in filling strength and filling ratio of partial filling flaw led to an increase in peak strength,with a decreasing trend in peak strength with the inclination of partial filling flaw.In terms of crack propagation pattern,the increasing filling strength of the partial filling flaw induced the transformation of the fracture mechanism toward deflection,with a tortuosity path,while the filling ratio and inclination of partial filling flaw led to fracture mechanism change from deflection to penetration and attraction,accompanied with a larger AE event source in filler.Accordingly,the b-value based on the Gutenberg-Richter equation fluctuated between 5 and 4 at low filling ratio and inclination and remained around 5 at high filling ratio and inclination of partial filling flaw.Related results may provide an application prospective for reservoir stimulation using the natural fracture system.展开更多
Fresh food products are highly susceptible to microbial contamination and oxidative deterioration during storage,necessitating effective preservation strategies.In the present study,we employed a rapid,scalable,and sa...Fresh food products are highly susceptible to microbial contamination and oxidative deterioration during storage,necessitating effective preservation strategies.In the present study,we employed a rapid,scalable,and safe microfluidic-blow-spinning technique to develop a novel multifunctional dual-layered nanofiber film featuring asymmetric wettability and antioxidant and antimicrobial properties.The films consisted of a hydrophobic polycaprolactone(PCL)/ethyl cellulose(EC)layer loaded with thymol and a hydrophilic polyurethane(PU)/polyvinylpyrrolidone(PVP)layer loaded with quercetin.The hydrophilic layer exhibited good antioxidant activity comparable with vitamin C,whereas the hydrophobic layer showed effective antibacterial activity against Escherichia coli and Staphylococcus aureus,92.3%and 98.0%,respectively.In addition,the dual-layered structure significantly improved the elongation at break from 133.28%to 168.81%and improved the thermal stability of the films.The above results indicate that the proposed dual-layered nanofiber film is a promising and sustainable solution for the postharvest preservation of fresh food products.展开更多
Aerosol acidity(pH)plays an important role in the multiphase chemical processes of atmospheric particles.In this study,we demonstrated the seasonal trends of aerosol pH calculated with the ISORROPIA-II model in a coas...Aerosol acidity(pH)plays an important role in the multiphase chemical processes of atmospheric particles.In this study,we demonstrated the seasonal trends of aerosol pH calculated with the ISORROPIA-II model in a coastal city of southeast China.We performed quantitative analysis on the various influencing factors on aerosol pH,and explored the responses of aerosol pH to different PM_(2.5)and O_(3)pollution levels.The results showed that the average aerosol pH was 2.92±0.61,following the order of winter>spring>summer>autumn.Sensitivity tests revealed that SO_(4)^(2−),NH_(x),T and RH triggered the variations of aerosol pH.Quantitative analysis results showed that T(37.9%-51.2%)was the main factors affecting pH variations in four seasons,followed by SO_(4)^(2−)(6.1%-23.7%),NH_(x)(7.2%-22.2%)and RH(0–14.2%).Totally,annual mean meteorological factors(52.9%)and chemical compositions(41.3%)commonly contributed the aerosolpH in the coastal city.The concentrations of PM_(2.5)was positively correlated with aerosol liquid water content(R^(2)=0.53)and aerosol pH(R^(2)=0.26),indicating that the increase in pH was related with the elevated NH_(4)NO_(3)and decreased SO_(4)^(2−),and also the changes of T and RH.The O_(x)(O_(3)+NO_(2))was moderately correlated with aerosol pH(R^(2)=-0.48),attributable to the fact that the proportion of SO_(4)^(2−)increased under high T and low RH conditions.The study strengthened our understanding of the contributions of influencing factors to aerosol pH,and also provided scientific evidences for chemical processes of atmospheric particles in coastal areas.展开更多
Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art...Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art,this paper analyzes the connection between the two in depth,elaborates on the manifestation of the fusion of virtual and reality in new media art creation,explores the challenges and problems it faces,and puts forward coping strategies with the aim of providing theoretical support for the development of the creation of new media art under the context of the meta-universe,and promoting the innovation and progress of art creation.展开更多
Objective:To explore the effect of applying safety culture construction in nursing management of infectious disease areas.Methods:During the one-year period from January 2024 to December 2024,patients admitted to the ...Objective:To explore the effect of applying safety culture construction in nursing management of infectious disease areas.Methods:During the one-year period from January 2024 to December 2024,patients admitted to the infectious disease area of our hospital were randomly selected for the study.92 patients were divided into two groups using a computerized double-blind method for intervention.The control group received routine nursing management,while the observation group applied safety culture construction management.The effects of nursing management in the two groups were studied and compared.Results:Before management,the nursing management quality scores of the two groups were evaluated,showing little difference in various scores,and the difference was not statistically significant(P>0.05).Through the implementation of nursing management,the scores of the two groups were significantly improved,and the observation group had significantly higher scores compared to the control group(P<0.05).Compared to the incidence of nursing risk events,the observation group(6.52%)was significantly lower than the control group(30.43%),and there was a significant difference between the two groups(P<0.05).The observation group had significantly higher satisfaction scores for nursing skills,health education,service attitude,and professionalism compared to the control group,indicating patient satisfaction with safety culture construction(P<0.05).Conclusion:Applying safety culture construction in nursing management of infectious disease areas has a preventive effect on nursing risk events and is beneficial for improving patients’risk cognition level.展开更多
The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual co...The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual coal in goaf on CO_(2)were studied by the isothermal adsorption test of CO_(2).Then,to accurately calculate the amount of adsorbed CO_(2)within the residual coal in the goaf,the bidisperse diffusion numerical model considering only Fick diffusion was modified in combination with the diffusion mechanisms.The simulation results showed that the modified model can well describe the diffusion behavior of CO_(2)in the residual coal matrix.Finally,the numerical simulation of CO_(2)sequestration in the goaf of abandoned coal mines was carried out,and the influence of different injection well deployment positions and various thicknesses of residual coal on the migration law and storage effect of CO_(2)in goaf was analyzed.The results showed that CO_(2)preferentially flowed into the caving zone with higher permeability.The distribution of CO_(2)streamlines in the goaf was the most dense in the caving zone and the streamlines in the fracture zone were gradually sparse from bottom to top.When the injection well was deployed at the interface of the two zones,the CO_(2)had the best seepage path.The total storage capacity within90 days was 7.702754×10^(6)kg,of which the free state storage capacity in the fracture of the goaf and the adsorbed state storage capacity in the residual coal were 6.611451×10^(6)and 1.091303×10^(6)kg,respectively.When the injection well was deployed in the middle of the residual coal seam in the goaf and the middle of the fracture zone,the total storage capacity at the same time was 7.613508×10^(6)and 6.021495×10^(6)kg,respectively.The coal with different thicknesses remaining at the bottom of the goaf significantly affected the adsorbed state storage,but had little effect on the free state storage.When the thickness of the residual coal seam was 0.20,0.35,and 0.50 m,the adsorbed state storage capacity within 130 days was 4.37623×10^(5),7.65791×10^(5),and 1.093406×10^(6)kg,respectively.展开更多
The regulation of superconductivity in thin films can provide important information on low-dimensional superconducting properties,and also has important reference values for the application in superconducting devices....The regulation of superconductivity in thin films can provide important information on low-dimensional superconducting properties,and also has important reference values for the application in superconducting devices.Herein,we report the successful regulation of both the superconductivity and normal-state properties of Nb films in a wide range by the controllable introduction of interstitial oxygen atoms.The lattice parameter is enhanced for an extent as large as 4.4%,and the normal-state resistivityρ_(n)is tuned for more than 15 times.The slope of upper critical field near T_(c)shows a close correlation withρ_(n)in a wide range.Importantly,it is found that the suppression of T_(c)by disorder reveals a linear dependence withρ_(n)in the region with an unchanged crystalline quality,which can be understood based on the picture of three-dimensional ballistic motion.展开更多
Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lu...Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .展开更多
目的 建立升麻饮片的高效液相色谱(HPLC)指纹图谱和分析其5种成分含量的一测多评(quantitative analysis of multicomponents by single-marker,QAMS)方法,实现对升麻饮片质量的系统评价。方法 采用HPLC法建立升麻饮片指纹图谱,运用相...目的 建立升麻饮片的高效液相色谱(HPLC)指纹图谱和分析其5种成分含量的一测多评(quantitative analysis of multicomponents by single-marker,QAMS)方法,实现对升麻饮片质量的系统评价。方法 采用HPLC法建立升麻饮片指纹图谱,运用相似度评价、聚类分析(cluster analysis,CA)、主成分分析(principal component analysis,PCA)和正交偏最小二乘-判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)等化学模式识别对指纹图谱进行分析;以异阿魏酸为内参物,建立分析咖啡酸、升麻素苷、阿魏酸、升麻素含量的QAMS法,并与外标法(external standard method,ESM)测定结果进行比较。结果 12批升麻饮片的HPLC指纹图谱中有13个共有峰,指认了该指纹图谱中的5个成分,分别为咖啡酸、升麻素苷、阿魏酸、异阿魏酸、升麻素,12批升麻饮片相似度为0.92~1.00,CA、PCA和OPLS-DA分析表明,供试升麻饮片可分为2类,差异性成分为峰2、3、4、7(阿魏酸)、8(异阿魏酸)、9(升麻素);建立了分析所指认的5种成分含量的QAMS方法,分析结果与ESM法测定的相应成分含量无显著差异。结论 所建立的HPLC指纹图谱和QAMS法操作简便、高效、经济、可靠,可为升麻饮片及其衍生产品的质量评价提供参考和依据。展开更多
This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through mic...This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.展开更多
基金supported by grants from the National Key R&D Program of China,No.2017YFC0909200(to DC)the National Natural Science Foundation of China,No.62075225(to HZ)+1 种基金Zhejiang Provincial Medical Health Science and Technology Project,No.2023XY053(to ZP)Zhejiang Provincial Traditional Chinese Medical Science and Technology Project,No.2023ZL703(to ZP).
文摘Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.
基金supported by the National Key Research Program of China(Grant Nos.2021YFA1401900,2022YFA1403300,and 2020YFA0309100)the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0302602 and 2024ZD0300103)+1 种基金the National Natural Science Foundation of China(Grant No.12074073)for samplefabrication and measurementthe support by the The Basic Research Program of the Chinese Academy of Sciences Based on Major Scientific Infrastructures(Grant No.JZHKYPT-2021-08).
文摘When a perpendicular magnetic field penetrates a thin slab of a type-Ⅱ superconductor it produces vortices,with one vortex per flux quantum,h/2e.The vortices interact repulsively and form an ordered array(Abrikosov lattice)in clean systems,while strong disorder changes the lattice into a vortex glass.The collective vortex dynamics is extremely vulnerable to external perturbations.Consequently,although of great importance,experimental observation is limited.Here we investigate type-Ⅱ superconducting films(PdBi_(2)and NbSe_(2))with surface acoustic waves(SAWs)at mK temperature.When sweeping the magnetic field at an extremely slow rate,we observe a series of spikes in the attenuation and velocity of the SAW,on average separated in field by approximately Hc1.We propose the following scenario:The vortex-free region at the edges of the film produces an edge barrier across which the vortices can enter or leave.When the applied field changes,the induced supercurrents flowing along this edge region lowers this barrier until there is an instability.At that point,vortices avalanche into(or out of)the bulk and change the vortex crystal,suggested by the sharp jump in each such spike.The vortices then gradually relax to a new stable pinned configuration,leading to a~30 s relaxation after the jump.Our observation enriches the limited experimental evidence on the important topic of real-time vortex dynamics in superconductors.
基金supported by the National Natural Science Foundation of China(No.52164022).
文摘This study investigated the effect of konjac glucomannan(KGM)on the flotation separation of calcite and scheelite.Micro-flotation tests showed that under the action of 50 mg/L KGM,the floatability of calcite notably decreased,while the impact on scheelite was negligible,resulting in a recovery difference of 82.53%.Fourier transform infrared(FTIR)spectroscopy and atomic force micro-scopy(AFM)analyses indicated the selective adsorption of KGM on the calcite surface.Test results of the zeta potential and UV-visible absorption spectroscopy revealed that KGM prevented the adsorption of sodium oleate on the calcite surface.X-ray photoelectron spec-troscopy(XPS)analysis further confirmed the chemical adsorption of KGM on the calcite surface and the formation of Ca(OH)_(2).The density functional theory(DFT)simulation results were consistent with the flotation tests,demonstrating the strong adsorption perform-ance of KGM on the calcite surface.This study offers a pathway for highly sustainable and cost-effective mineral processing by utilizing the unique properties of biopolymers such as KGM to separate valuable minerals from gangue minerals.
基金financially supported by the First-Class Curriculum Program at the School of Economics and Management,University of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(42041005)the National Social Science Foundation of China(23BTQ054)。
文摘Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the frontiers and key areas of grassland degradation research has not been achieved due to the limitations of traditional scientometrics methods.The present synthesis of information employed BERTopic,an advanced natural language processing tool,to analyze the extensive ecological literature on grassland degradation.We compiled a dataset of 4,504 publications from the Web of Science core collection database and used it to evaluate the geographic distribution and temporal evolution of different grassland types and available knowledge on the subject.Our analysis identified key topics in the global grassland degradation research domain,including the effects of grassland degradation on ecosystem functions,grassland ecological restoration and biodiversity conservation,erosion processes and hydrological models in grasslands,and others.The BERTopic analysis significantly outperforms traditional methods in identifying complex and evolving topics in large datasets of literature.Compared to traditional scientometrics analysis,BERTopic provides a more comprehensive perspective on the research areas,revealing not only popular topics but also emerging research areas that traditional methods may overlook,although scientometrics offers more specificity and detail.Therefore,we argue for the simultaneous use of both approaches to achieve more systematic and comprehensive assessments of specific research areas.This study represents an emerging application of BERTopic algorithms in ecological research,particularly in the critical research focused on global grassland degradation.It also highlights the need for integrating advanced computational methods in ecological research in this era of data explosion.Tools like the BERTopic algorithm are essential for enhancing our understanding of complex environmental problems,and it marks an important stride towards more sophisticated,data-driven analysis in ecology.
基金supports from the projects by the NSFC[51771166]the Hebei Natural Science Foundation[E2019203452,E2021203011]+3 种基金the key project of department of education of Hebei province[ZD2021107]project of the central government guiding local science and technology development[216Z1001G]Cultivation Project for Basic Research and Innovation of Yanshan University[2021LGZD002]project of State Key Laboratory of Materials Processing and Die&Mould Technology[P2023-004]are gratefully acknowledged.
文摘Molecular dynamics(MD)simulation is employed to investigate the deformation behavior under various loading paths and strain rates of nanocrystalline magnesium(NC Mg)with[0001]texture.Atomic-scale structural evolution of NC Mg was performed under uniaxial and biaxial loadings.In tension process,compression twins and basal slip dominate,while the compression process is dominated by tension twins.The activation mechanism of twinning is highly sensitive to the loading path and grain orientation.Meanwhile,the effect of strain rate on the structural evolution of NC Mg was investigated.It is found that the effect of strain rate on the plastic deformation of NC Mg is reflected through the plasticity delays and the way to release the stress.As the strain rate decreases,the plastic deformation mechanism gradually changes from intragranular to grain boundary.Some significant potential deformation mechanisms in the loading process were studied.It is observed that{1121}twins nucleated inside the grains,and the thickening process is completed by basal〈a〉slip of the twin boundary.The strain compatibility between twins is automatically optimized with loading.Moreover,the detwinning mechanism caused by the interaction between twins and basal stacking faults is clarified.
基金supported by the National Key R&D Program of China(Grant No.2022YFE0128300).
文摘The fracture behavior of natural fracture in the geological reservoir subjected to filling property,affects the crack initiation and propagation under stress perturbation.Partial filling flaws were intermediate between open fractures and filled fractures,the fracture response may be worth exploring.In this work,the effect of the filling property of sandstone with partial filling flaws on the fracture behavior was systematically investigated based on three-point bending tests and the numerical approach of discrete element method(DEM).In the laboratory,semi-circular three-point bending tests were carried out with partial filling flaws of various filling strengths.Based on this,numerical simulations were used to further investigate the effect of the filling ratio and the inclination of the partial filling flaw on the mechanical and fracture responses,and the effect of the partial filling flaw under mixed-mode loading on the fracture mechanism was elucidated coupled with acoustic emission(AE)characteristics.The obtained results showed that the increase in filling strength and filling ratio of partial filling flaw led to an increase in peak strength,with a decreasing trend in peak strength with the inclination of partial filling flaw.In terms of crack propagation pattern,the increasing filling strength of the partial filling flaw induced the transformation of the fracture mechanism toward deflection,with a tortuosity path,while the filling ratio and inclination of partial filling flaw led to fracture mechanism change from deflection to penetration and attraction,accompanied with a larger AE event source in filler.Accordingly,the b-value based on the Gutenberg-Richter equation fluctuated between 5 and 4 at low filling ratio and inclination and remained around 5 at high filling ratio and inclination of partial filling flaw.Related results may provide an application prospective for reservoir stimulation using the natural fracture system.
基金supported by the Fundamental Research Funds for the Zhejiang Provincial Universities,China(No.226-2024-00084).
文摘Fresh food products are highly susceptible to microbial contamination and oxidative deterioration during storage,necessitating effective preservation strategies.In the present study,we employed a rapid,scalable,and safe microfluidic-blow-spinning technique to develop a novel multifunctional dual-layered nanofiber film featuring asymmetric wettability and antioxidant and antimicrobial properties.The films consisted of a hydrophobic polycaprolactone(PCL)/ethyl cellulose(EC)layer loaded with thymol and a hydrophilic polyurethane(PU)/polyvinylpyrrolidone(PVP)layer loaded with quercetin.The hydrophilic layer exhibited good antioxidant activity comparable with vitamin C,whereas the hydrophobic layer showed effective antibacterial activity against Escherichia coli and Staphylococcus aureus,92.3%and 98.0%,respectively.In addition,the dual-layered structure significantly improved the elongation at break from 133.28%to 168.81%and improved the thermal stability of the films.The above results indicate that the proposed dual-layered nanofiber film is a promising and sustainable solution for the postharvest preservation of fresh food products.
基金supported by the National Natural Science Foundation of China(Nos.42277091 and U22A20578)Xiamen Youth Innovation Fund Project(No.3502Z20206094)+1 种基金Fujian Provincial Environmental Protection Science&Technology Plan Projects(No.2023R004)Xiamen Atmospheric Environment Observation and Research Station of Fujian Province.
文摘Aerosol acidity(pH)plays an important role in the multiphase chemical processes of atmospheric particles.In this study,we demonstrated the seasonal trends of aerosol pH calculated with the ISORROPIA-II model in a coastal city of southeast China.We performed quantitative analysis on the various influencing factors on aerosol pH,and explored the responses of aerosol pH to different PM_(2.5)and O_(3)pollution levels.The results showed that the average aerosol pH was 2.92±0.61,following the order of winter>spring>summer>autumn.Sensitivity tests revealed that SO_(4)^(2−),NH_(x),T and RH triggered the variations of aerosol pH.Quantitative analysis results showed that T(37.9%-51.2%)was the main factors affecting pH variations in four seasons,followed by SO_(4)^(2−)(6.1%-23.7%),NH_(x)(7.2%-22.2%)and RH(0–14.2%).Totally,annual mean meteorological factors(52.9%)and chemical compositions(41.3%)commonly contributed the aerosolpH in the coastal city.The concentrations of PM_(2.5)was positively correlated with aerosol liquid water content(R^(2)=0.53)and aerosol pH(R^(2)=0.26),indicating that the increase in pH was related with the elevated NH_(4)NO_(3)and decreased SO_(4)^(2−),and also the changes of T and RH.The O_(x)(O_(3)+NO_(2))was moderately correlated with aerosol pH(R^(2)=-0.48),attributable to the fact that the proportion of SO_(4)^(2−)increased under high T and low RH conditions.The study strengthened our understanding of the contributions of influencing factors to aerosol pH,and also provided scientific evidences for chemical processes of atmospheric particles in coastal areas.
文摘Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art,this paper analyzes the connection between the two in depth,elaborates on the manifestation of the fusion of virtual and reality in new media art creation,explores the challenges and problems it faces,and puts forward coping strategies with the aim of providing theoretical support for the development of the creation of new media art under the context of the meta-universe,and promoting the innovation and progress of art creation.
文摘Objective:To explore the effect of applying safety culture construction in nursing management of infectious disease areas.Methods:During the one-year period from January 2024 to December 2024,patients admitted to the infectious disease area of our hospital were randomly selected for the study.92 patients were divided into two groups using a computerized double-blind method for intervention.The control group received routine nursing management,while the observation group applied safety culture construction management.The effects of nursing management in the two groups were studied and compared.Results:Before management,the nursing management quality scores of the two groups were evaluated,showing little difference in various scores,and the difference was not statistically significant(P>0.05).Through the implementation of nursing management,the scores of the two groups were significantly improved,and the observation group had significantly higher scores compared to the control group(P<0.05).Compared to the incidence of nursing risk events,the observation group(6.52%)was significantly lower than the control group(30.43%),and there was a significant difference between the two groups(P<0.05).The observation group had significantly higher satisfaction scores for nursing skills,health education,service attitude,and professionalism compared to the control group,indicating patient satisfaction with safety culture construction(P<0.05).Conclusion:Applying safety culture construction in nursing management of infectious disease areas has a preventive effect on nursing risk events and is beneficial for improving patients’risk cognition level.
基金Fundamental Research Funds for the Central Universities,Grant/Award Number:2024KYJD1012。
文摘The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual coal in goaf on CO_(2)were studied by the isothermal adsorption test of CO_(2).Then,to accurately calculate the amount of adsorbed CO_(2)within the residual coal in the goaf,the bidisperse diffusion numerical model considering only Fick diffusion was modified in combination with the diffusion mechanisms.The simulation results showed that the modified model can well describe the diffusion behavior of CO_(2)in the residual coal matrix.Finally,the numerical simulation of CO_(2)sequestration in the goaf of abandoned coal mines was carried out,and the influence of different injection well deployment positions and various thicknesses of residual coal on the migration law and storage effect of CO_(2)in goaf was analyzed.The results showed that CO_(2)preferentially flowed into the caving zone with higher permeability.The distribution of CO_(2)streamlines in the goaf was the most dense in the caving zone and the streamlines in the fracture zone were gradually sparse from bottom to top.When the injection well was deployed at the interface of the two zones,the CO_(2)had the best seepage path.The total storage capacity within90 days was 7.702754×10^(6)kg,of which the free state storage capacity in the fracture of the goaf and the adsorbed state storage capacity in the residual coal were 6.611451×10^(6)and 1.091303×10^(6)kg,respectively.When the injection well was deployed in the middle of the residual coal seam in the goaf and the middle of the fracture zone,the total storage capacity at the same time was 7.613508×10^(6)and 6.021495×10^(6)kg,respectively.The coal with different thicknesses remaining at the bottom of the goaf significantly affected the adsorbed state storage,but had little effect on the free state storage.When the thickness of the residual coal seam was 0.20,0.35,and 0.50 m,the adsorbed state storage capacity within 130 days was 4.37623×10^(5),7.65791×10^(5),and 1.093406×10^(6)kg,respectively.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0670000)the National Key Research and Development Program of China(Grant No.2023YFB4404904)+1 种基金the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2020B0303030002)the Autonomous Deployment Project of State Key Laboratory of Materials for Integrated Circuits(Grant No.SKLJC-Z2024-B04).
文摘The regulation of superconductivity in thin films can provide important information on low-dimensional superconducting properties,and also has important reference values for the application in superconducting devices.Herein,we report the successful regulation of both the superconductivity and normal-state properties of Nb films in a wide range by the controllable introduction of interstitial oxygen atoms.The lattice parameter is enhanced for an extent as large as 4.4%,and the normal-state resistivityρ_(n)is tuned for more than 15 times.The slope of upper critical field near T_(c)shows a close correlation withρ_(n)in a wide range.Importantly,it is found that the suppression of T_(c)by disorder reveals a linear dependence withρ_(n)in the region with an unchanged crystalline quality,which can be understood based on the picture of three-dimensional ballistic motion.
文摘Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .
文摘目的 建立升麻饮片的高效液相色谱(HPLC)指纹图谱和分析其5种成分含量的一测多评(quantitative analysis of multicomponents by single-marker,QAMS)方法,实现对升麻饮片质量的系统评价。方法 采用HPLC法建立升麻饮片指纹图谱,运用相似度评价、聚类分析(cluster analysis,CA)、主成分分析(principal component analysis,PCA)和正交偏最小二乘-判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)等化学模式识别对指纹图谱进行分析;以异阿魏酸为内参物,建立分析咖啡酸、升麻素苷、阿魏酸、升麻素含量的QAMS法,并与外标法(external standard method,ESM)测定结果进行比较。结果 12批升麻饮片的HPLC指纹图谱中有13个共有峰,指认了该指纹图谱中的5个成分,分别为咖啡酸、升麻素苷、阿魏酸、异阿魏酸、升麻素,12批升麻饮片相似度为0.92~1.00,CA、PCA和OPLS-DA分析表明,供试升麻饮片可分为2类,差异性成分为峰2、3、4、7(阿魏酸)、8(异阿魏酸)、9(升麻素);建立了分析所指认的5种成分含量的QAMS方法,分析结果与ESM法测定的相应成分含量无显著差异。结论 所建立的HPLC指纹图谱和QAMS法操作简便、高效、经济、可靠,可为升麻饮片及其衍生产品的质量评价提供参考和依据。
基金supported by the National Natural Science Foundation of China (No.52164022).
文摘This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.
