This work managed the extrusion strain path by designing various extrusion die cavities,successfully realizing the texture modification for the ZK60 magnesium alloy.The mechanisms involving the texture dependence on t...This work managed the extrusion strain path by designing various extrusion die cavities,successfully realizing the texture modification for the ZK60 magnesium alloy.The mechanisms involving the texture dependence on the extrusion die cavity as well as their effects on the mechanical properties were emphatically investigated.Results showed that dynamic recrystallization refined the grain size and improved the microstructure homogeneity in the three extrusion specimens,but did not produce too large microstructure differences.By comparison,significant texture differences developed owing to the various extrusion die cavities,which here were mainly reflected in the strong or weak texture components for the c-axes//TD and the c-axes//ND.Such texture differences started from the deformation texture instead of the recrystallization texture whose roles only consisted in dispersing the texture component and reducing the texture intensity.The results from the finite element analysis and the visco-plastic self-consistent model indicated that,in order to accommodate the different strain components induced by the extrusion die cavities,slip systems or tension twinning were activated differently,and this was the critical reason causing the above texture differences.One modified Hall-Petch relationship was adopted to analyze the conjoint effects of grain refinement and texture variation on the yield stress.Additionally,the quantitative results about deformation mechanism activation fractions demonstrated that the texture variations influenced the competition relationships between the twinning induced deformation and the slip dominant deformation,and the former generally produced the lower yield stress and the increasing stage of strain hardening rate,while the latter produced the higher yield stress and the continuous decline of strain hardening rate.展开更多
The evolution of the microstructure and mechanical properties of WE43 magnesium alloy during multipass hot rolling was investigated.Results revealed that multipass hot rolling promoted the formation of small second ph...The evolution of the microstructure and mechanical properties of WE43 magnesium alloy during multipass hot rolling was investigated.Results revealed that multipass hot rolling promoted the formation of small second phases,which was conducive to multiple dynamic recrystallization,consequently improving the microstructure homogeneity and refining the average grain size from 34.3μm in the initial material to 8.83μm.Meanwhile,the rolling deformation rotated abundant c-axis of the grains in the normal direction,resulting in a strong fiber texture.The yield strength in the rolling direction(RD)was improved from 164 MPa in the initial material to 324 MPa in the Pass 3 sheet due to fine-grained strengthening,second-phase strengthening,and texture modification.In addition,the distribution maps of the deformation mechanism indicated that the yield strength anisotropy between the RD and the transverse direction(TD)can be attributed to the effects of the texture component on the dominant mechanism.The dominant deformation mechanism during the tensile test was the prismatic slip caused by the strong basal texture of the RD,whereas it had a lesser proportion of prismatic slip under the influence of the weak basal texture of the TD.Compared to the basal slip,the higher critical resolved shear stress of the prismatic slip resulted in a higher increase in yield strength along the RD at approximately 51 MPa than that along the TD(RD:increase of 160 MPa;TD:increase of 109 MPa).展开更多
This paper explored how the work hardening process enhances the yield strength(YS)of magnesium alloy and established a novel quantitative relationship between microstructure and YS.The YS of an extruded Mg–Nd–Zn–Zr...This paper explored how the work hardening process enhances the yield strength(YS)of magnesium alloy and established a novel quantitative relationship between microstructure and YS.The YS of an extruded Mg–Nd–Zn–Zr alloy was nearly tripled by rotary swaging at 200℃,attributing to dislocation accumulation,grain fragmentation,and basal texture formation.A modified Hall–Petch relationship(GM–HP)was established by introducing the equivalent orientation factor and dislocation density to accurately quantify the YS and the contribution of each strengthening mechanism.The contributions of dislocation hardening and grain boundary strengthening were multiplied by the strong basal texture.This paper offered valuable insights and guidance for designing and optimizing high-strength wrought magnesium alloys and their plastic processing methods.展开更多
Background:Thepostdoctoral workforce has been expanding worldwide,playing a vital role in scientific progress,innovation,and knowledge dissemination.Nevertheless,their mental health is also increasingly a global conce...Background:Thepostdoctoral workforce has been expanding worldwide,playing a vital role in scientific progress,innovation,and knowledge dissemination.Nevertheless,their mental health is also increasingly a global concern,exacerbated by challenges such as intense competition,growing responsibilities,and pressure to publish.Purpose:Research on work characteristics is essential for guiding policy and interventions,offering valuable insights into the factors that affect postdoctoral researchers’mental health.Hence,this study aims to examine the impact of work characteristics on postdocs’mental health and explore the underlyingmechanisms drawing on the Job Demands-Resources(JD-R)model.Methods:Using data from Nature’s 2020 Global Postdoc Survey,this study examines how work-related factors influence mental health through regression analysis and percentile bootstrap methods,and eight hypotheses are proposed.Results:Working hours,overtime frequency,and job insecurity negatively predicted postdocs’work-life balance satisfaction and directly increased the likelihood of mental health problems.Mentor support,job autonomy,and rewards enhanced work-life balance satisfaction and directly decreased the possibility of mental health problems.All six job characteristics indirectly influenced postdocs’mental health through worklife balance satisfaction.Working hours had a stronger negative impact on work-life balance satisfaction for female postdocs,while job insecurity had a stronger negative impact onmale postdocs’work-life balance satisfaction.However,no significant gender differences were found in the impact of overtime frequency on work-life balance satisfaction.Conclusion:Job demands(working hours,overtime frequency,and job insecurity)significantly increased postdocs’mental health problems whereas job resources(mentor support,job autonomy,and rewards)mitigated these problems.All these impacts were mediated through work-life balance satisfaction.Gender differences were evident regarding the relationship between job demands(working hours and job insecurity)andwork-life balance satisfaction.These findings provide a basis for future research on the broader causal relationships between work characteristics and postdocs’mental health,as well as studies examining variations across countries,cultures,and disciplines.This study also offers actionable recommendations for institutions,funding agencies,and mentors to foster better working conditions to improve postdocs’well-being.展开更多
为了开发丙酮酸高产菌株,以大肠杆菌MG1655为出发菌株,通过基因敲除阻断副产物途径构建了产丙酮酸大肠杆菌工程菌KLPP。进一步利用p UT Mini-Tn5载体进行转座子随机突变,构建了含有7 197个单克隆的突变体文库。使用基于丙酮酸的二硝基...为了开发丙酮酸高产菌株,以大肠杆菌MG1655为出发菌株,通过基因敲除阻断副产物途径构建了产丙酮酸大肠杆菌工程菌KLPP。进一步利用p UT Mini-Tn5载体进行转座子随机突变,构建了含有7 197个单克隆的突变体文库。使用基于丙酮酸的二硝基苯肼显色法,建立了96孔板-酶标仪快速筛选方法,经过两轮的筛选,成功筛选到了6个突变体菌株,比KLPP丙酮酸产量提高了38%、31%、19%、28%、44%和14%。利用全基因组重测序确定了其转座子插入的位置,进而确定了可能影响丙酮酸产量的基因位点,为后续菌株改造工作奠定了基础。展开更多
The rolling direction（RD） and the transverse direction（TD） samples were obtained from an as-rolled ZK60 magnesium alloy sheet with strong anisotropy of initial texture and their mechanical properties were tested a...The rolling direction（RD） and the transverse direction（TD） samples were obtained from an as-rolled ZK60 magnesium alloy sheet with strong anisotropy of initial texture and their mechanical properties were tested at various deformation temperatures. Meanwhile, the microstructure and texture of these samples after fracture were investigated. Results revealed that a higher flow stress along the RD than that along the TD at room temperature were ascribed to the strong anisotropy of transitional texture, and this texture effect was remarkably weakened with the increase of deformation temperature. Deformation structure was dominant at 100℃, and was replaced by dynamic recrystallization structure when the deformation temperature increased to 200℃ and 300℃. The texture presented a strong texture（transitional texture in the RD sample and basal texture in the TD sample） at 100℃, but its intensity visibly decreased and texture components became more disperse at 200℃ and 300℃. These microstructure and texture results were employed in conjunction with calculated results to argue that raising deformation temperature could increase the activity of non-basal slip by tailoring the relative critical resolved shear stress of each deformation mode and finally result in low texture effect on mechanical anisotropy.展开更多
An integrated calculated approach based on weakly coupled finite element(FEM)-viscoplastic selfconsistent(VPSC)model was established to simulate the texture evolution during the variable strain path extrusion process ...An integrated calculated approach based on weakly coupled finite element(FEM)-viscoplastic selfconsistent(VPSC)model was established to simulate the texture evolution during the variable strain path extrusion process of magnesium alloys.The spiral die extrusion(SDE)process with additional circumferential shear deformation was applied to investigate the effect of path control on texture adjustment and verify the accuracy of the model.The results indicated that the additional spiral shear resulting from the overall inclined flow path effectively reduced the intensity of the{0002}//ED fiber texture by suppressing basal slip activation in the core area,while the local shear deformation along the spiral equal channel strain path led to the formation of an inclined{0002}//ND plane texture on the side.Using the modified Hall-Petch relationship,the correlation between texture and yield strength was quantified.Specifically,the weakening of the texture effectively suppressed{10-12}tensile twinning,which compensated for the deficiency of compressive yield strength without significantly sacrificing tensile yield strength,and thus improved the tension-compression asymmetry.Furthermore,the strongly inclined{0002}//ND plane texture inhibited the widespread activation of basal slip during tensile yielding,thereby enhancing the yield strength.展开更多
The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT pro...The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT processed IF steel disks, giving lower hardness in the center and higher hardness in the edge regions. However, on the axisymmetrical section testing plane of the disks’ thickness direction, there is a soft zone near the surface of disks. Further results from radius testing plane of different depths from the surface of HPT processed disks show that the inhomogeneity rules of hardness distribution on the radius direction are similar to that on the thickness direction. Compared with the initial state, different stages of HPT (compression and compression + torsion) can both remarkably increase the hardness of IF steel disks. Microstructure investigation results can give a well support to verify the rules of hardness distribution, showing hardly no change of grains in center and sever plastic deformation in edge. The inhomogeneous distribution of stress and strain with the huge friction between anvil and disks in the process of HPT play an important role of hardness and microstructure distribution.展开更多
The heterojunction of single-wall carbon nanotubes(SWCNTs)and perovskite quantum dots(QDs)shows excellent photodetection performances due to the combination of the advantages of high carrier mobility of SWCNTs and hig...The heterojunction of single-wall carbon nanotubes(SWCNTs)and perovskite quantum dots(QDs)shows excellent photodetection performances due to the combination of the advantages of high carrier mobility of SWCNTs and high absorption coefficient of perovskite QDs.However,the band structure of a SWCNT is determined by its atomic arrangement structure.How the structure of SWCNTs affects the photoelectric performance of the composite film remains elusive.Here,we systematically explored the diameter effect of SWCNTs with different bandgaps on the photodetection performances of SWCNTs/perovskite QDs heterojunction films by integrating semiconducting SWCNTs(s-SWCNTs)with different diameters with CsPbBr3 QDs.The results show that with an increase in diameter of s-SWCNTs,the heterojunction exhibits increasing responsivity(R),detectivity(D*),and faster response time.The great improvement in the optoelectronic performances of devices should be attributed to the higher carrier mobility of larger-diameter SWCNT films and the increasing built-in electric field at the heterojunction interfaces between larger-diameter SWCNTs and CsPbBr3 QDs,which enhances the separation of the photogenerated excitons and the transport of the resulted carriers in SWCNT films.展开更多
Hydrological modeling,leveraging mathematical formulations to represent the hydrological cycle,is a pivotal tool in representing the spatiotemporal dynamics and distribution patterns inherent in hydrology.These models...Hydrological modeling,leveraging mathematical formulations to represent the hydrological cycle,is a pivotal tool in representing the spatiotemporal dynamics and distribution patterns inherent in hydrology.These models serve a dual purpose:they validate theoretical robustness and applicability via observational data and project future trends,thereby bridging the understanding and prediction of natural processes.In rapid advancements in computational methodologies and the continuous evolution of observational and experimental techniques,the development of numerical hydrological models based on physicallybased surface-subsurface process coupling have accelerated.Anchored in micro-scale conservation principles and physical equations,these models employ numerical techniques to integrate surface and subsurface hydrodynamics,thus replicating the macro-scale hydrological responses of watersheds.Numerical hydrological models have emerged as a leading and predominant trend in hydrological modeling due to their explicit representation of physical processes,heightened by their spatiotemporal resolution and reliance on interdisciplinary integration.This article focuses on the theoretical foundation of surface-subsurface numerical hydrological models.It includes a comparative and analytical discussion of leading numerical hydrological models,encompassing model architecture,numerical solution strategies,spatial representation,and coupling algorithms.Additionally,this paper contrasts these models with traditional hydrological models,thereby delineating the relative merits,drawbacks,and future directions of numerical hydrological modeling.展开更多
Crop residue-based biochar(CRB)has shown great potential for removing trace elements(TEs)from aquatic matrices.Despite the increasing interest in this area,no review has focused specifically on the efficacy of CRB for...Crop residue-based biochar(CRB)has shown great potential for removing trace elements(TEs)from aquatic matrices.Despite the increasing interest in this area,no review has focused specifically on the efficacy of CRB for TEs removal in aquatic environments.This comprehensive review examines the global TEs water contamination status with an emphasis on their sources,compositional metrics for crop residue feedstock(proximate,ultimate,and lignocellulosic properties),and the potential use of CRB for TEs removal in aquatic media.It also evaluates the factors that affect the ability of CRB to remove TEs,such as feedstock type,production conditions,water pH,background electrolytes,water temperature,CRB/water ratio,and underlying pollutant sorption mechanisms.This review also discusses the practical applications of CRB in real water samples and engineering considerations for designing CRB with improved physicochemical properties,treatment efficiencies,and regeneration abilities.Additionally,the cost-benefit and economic assessment of CRB,challenges,and future research directions related to CRB are highlighted to promote research on this sustainable source of biochar.By elucidating the prospects of CRB as an adsorbent,this review emphasizes the need for continued research on its practical implications for environmentally relevant pollutant concentrations.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52205344,51925401)Postdoctoral Research Foundation of China(Grant No.2023M732398)+1 种基金National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(Grant No.WDZC2023-1)Key Research and Development Program of Shandong Province(Grant No.2023CXPT066).
文摘This work managed the extrusion strain path by designing various extrusion die cavities,successfully realizing the texture modification for the ZK60 magnesium alloy.The mechanisms involving the texture dependence on the extrusion die cavity as well as their effects on the mechanical properties were emphatically investigated.Results showed that dynamic recrystallization refined the grain size and improved the microstructure homogeneity in the three extrusion specimens,but did not produce too large microstructure differences.By comparison,significant texture differences developed owing to the various extrusion die cavities,which here were mainly reflected in the strong or weak texture components for the c-axes//TD and the c-axes//ND.Such texture differences started from the deformation texture instead of the recrystallization texture whose roles only consisted in dispersing the texture component and reducing the texture intensity.The results from the finite element analysis and the visco-plastic self-consistent model indicated that,in order to accommodate the different strain components induced by the extrusion die cavities,slip systems or tension twinning were activated differently,and this was the critical reason causing the above texture differences.One modified Hall-Petch relationship was adopted to analyze the conjoint effects of grain refinement and texture variation on the yield stress.Additionally,the quantitative results about deformation mechanism activation fractions demonstrated that the texture variations influenced the competition relationships between the twinning induced deformation and the slip dominant deformation,and the former generally produced the lower yield stress and the increasing stage of strain hardening rate,while the latter produced the higher yield stress and the continuous decline of strain hardening rate.
基金financially supported by National Natural Science Foundation of China(Nos.52205344 and 51925401)the Postdoctoral Research Foundation of China(No.2023M732398)+1 种基金the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact,China(No.WDZC2023-1)the Key Research and Development Program of Shandong Province,China(No.2023CXPT066)。
文摘The evolution of the microstructure and mechanical properties of WE43 magnesium alloy during multipass hot rolling was investigated.Results revealed that multipass hot rolling promoted the formation of small second phases,which was conducive to multiple dynamic recrystallization,consequently improving the microstructure homogeneity and refining the average grain size from 34.3μm in the initial material to 8.83μm.Meanwhile,the rolling deformation rotated abundant c-axis of the grains in the normal direction,resulting in a strong fiber texture.The yield strength in the rolling direction(RD)was improved from 164 MPa in the initial material to 324 MPa in the Pass 3 sheet due to fine-grained strengthening,second-phase strengthening,and texture modification.In addition,the distribution maps of the deformation mechanism indicated that the yield strength anisotropy between the RD and the transverse direction(TD)can be attributed to the effects of the texture component on the dominant mechanism.The dominant deformation mechanism during the tensile test was the prismatic slip caused by the strong basal texture of the RD,whereas it had a lesser proportion of prismatic slip under the influence of the weak basal texture of the TD.Compared to the basal slip,the higher critical resolved shear stress of the prismatic slip resulted in a higher increase in yield strength along the RD at approximately 51 MPa than that along the TD(RD:increase of 160 MPa;TD:increase of 109 MPa).
基金supported by National Natural Science Foundation of China(Grant No.51975146)Natural Science Foundation of Shandong Province(Grant No.ZR2020QE171)。
文摘This paper explored how the work hardening process enhances the yield strength(YS)of magnesium alloy and established a novel quantitative relationship between microstructure and YS.The YS of an extruded Mg–Nd–Zn–Zr alloy was nearly tripled by rotary swaging at 200℃,attributing to dislocation accumulation,grain fragmentation,and basal texture formation.A modified Hall–Petch relationship(GM–HP)was established by introducing the equivalent orientation factor and dislocation density to accurately quantify the YS and the contribution of each strengthening mechanism.The contributions of dislocation hardening and grain boundary strengthening were multiplied by the strong basal texture.This paper offered valuable insights and guidance for designing and optimizing high-strength wrought magnesium alloys and their plastic processing methods.
文摘Background:Thepostdoctoral workforce has been expanding worldwide,playing a vital role in scientific progress,innovation,and knowledge dissemination.Nevertheless,their mental health is also increasingly a global concern,exacerbated by challenges such as intense competition,growing responsibilities,and pressure to publish.Purpose:Research on work characteristics is essential for guiding policy and interventions,offering valuable insights into the factors that affect postdoctoral researchers’mental health.Hence,this study aims to examine the impact of work characteristics on postdocs’mental health and explore the underlyingmechanisms drawing on the Job Demands-Resources(JD-R)model.Methods:Using data from Nature’s 2020 Global Postdoc Survey,this study examines how work-related factors influence mental health through regression analysis and percentile bootstrap methods,and eight hypotheses are proposed.Results:Working hours,overtime frequency,and job insecurity negatively predicted postdocs’work-life balance satisfaction and directly increased the likelihood of mental health problems.Mentor support,job autonomy,and rewards enhanced work-life balance satisfaction and directly decreased the possibility of mental health problems.All six job characteristics indirectly influenced postdocs’mental health through worklife balance satisfaction.Working hours had a stronger negative impact on work-life balance satisfaction for female postdocs,while job insecurity had a stronger negative impact onmale postdocs’work-life balance satisfaction.However,no significant gender differences were found in the impact of overtime frequency on work-life balance satisfaction.Conclusion:Job demands(working hours,overtime frequency,and job insecurity)significantly increased postdocs’mental health problems whereas job resources(mentor support,job autonomy,and rewards)mitigated these problems.All these impacts were mediated through work-life balance satisfaction.Gender differences were evident regarding the relationship between job demands(working hours and job insecurity)andwork-life balance satisfaction.These findings provide a basis for future research on the broader causal relationships between work characteristics and postdocs’mental health,as well as studies examining variations across countries,cultures,and disciplines.This study also offers actionable recommendations for institutions,funding agencies,and mentors to foster better working conditions to improve postdocs’well-being.
文摘为了开发丙酮酸高产菌株,以大肠杆菌MG1655为出发菌株,通过基因敲除阻断副产物途径构建了产丙酮酸大肠杆菌工程菌KLPP。进一步利用p UT Mini-Tn5载体进行转座子随机突变,构建了含有7 197个单克隆的突变体文库。使用基于丙酮酸的二硝基苯肼显色法,建立了96孔板-酶标仪快速筛选方法,经过两轮的筛选,成功筛选到了6个突变体菌株,比KLPP丙酮酸产量提高了38%、31%、19%、28%、44%和14%。利用全基因组重测序确定了其转座子插入的位置,进而确定了可能影响丙酮酸产量的基因位点,为后续菌株改造工作奠定了基础。
基金supported financially by the National Natural Science Foundation of China (No. 51401064)the Sci-tech Development Project in Shandong Province (No. 2014GGX10211)+1 种基金the Sci-tech Major Project in Shandong Province (No. 2015ZDJQ02002)the Fundamental Research Funds for the Central Universities (No. HIT.NSRIF.2016109)
文摘The rolling direction（RD） and the transverse direction（TD） samples were obtained from an as-rolled ZK60 magnesium alloy sheet with strong anisotropy of initial texture and their mechanical properties were tested at various deformation temperatures. Meanwhile, the microstructure and texture of these samples after fracture were investigated. Results revealed that a higher flow stress along the RD than that along the TD at room temperature were ascribed to the strong anisotropy of transitional texture, and this texture effect was remarkably weakened with the increase of deformation temperature. Deformation structure was dominant at 100℃, and was replaced by dynamic recrystallization structure when the deformation temperature increased to 200℃ and 300℃. The texture presented a strong texture（transitional texture in the RD sample and basal texture in the TD sample） at 100℃, but its intensity visibly decreased and texture components became more disperse at 200℃ and 300℃. These microstructure and texture results were employed in conjunction with calculated results to argue that raising deformation temperature could increase the activity of non-basal slip by tailoring the relative critical resolved shear stress of each deformation mode and finally result in low texture effect on mechanical anisotropy.
基金supported by the National Natural Science Foundation of China(Grant Nos.51975146,52205344)Shandong Province Natural Science Foundation(Grant No.ZR2020QE171)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(Nos.NRF-2021R1A2C3006662,NRF-2022R1A5A1030054).
文摘An integrated calculated approach based on weakly coupled finite element(FEM)-viscoplastic selfconsistent(VPSC)model was established to simulate the texture evolution during the variable strain path extrusion process of magnesium alloys.The spiral die extrusion(SDE)process with additional circumferential shear deformation was applied to investigate the effect of path control on texture adjustment and verify the accuracy of the model.The results indicated that the additional spiral shear resulting from the overall inclined flow path effectively reduced the intensity of the{0002}//ED fiber texture by suppressing basal slip activation in the core area,while the local shear deformation along the spiral equal channel strain path led to the formation of an inclined{0002}//ND plane texture on the side.Using the modified Hall-Petch relationship,the correlation between texture and yield strength was quantified.Specifically,the weakening of the texture effectively suppressed{10-12}tensile twinning,which compensated for the deficiency of compressive yield strength without significantly sacrificing tensile yield strength,and thus improved the tension-compression asymmetry.Furthermore,the strongly inclined{0002}//ND plane texture inhibited the widespread activation of basal slip during tensile yielding,thereby enhancing the yield strength.
文摘The inhomogeneous hardness distribution of high pressure torsion (HPT) processed IF steel disks along different directions is investigated. The results indicated that there exists inhomogeneous distribution in HPT processed IF steel disks, giving lower hardness in the center and higher hardness in the edge regions. However, on the axisymmetrical section testing plane of the disks’ thickness direction, there is a soft zone near the surface of disks. Further results from radius testing plane of different depths from the surface of HPT processed disks show that the inhomogeneity rules of hardness distribution on the radius direction are similar to that on the thickness direction. Compared with the initial state, different stages of HPT (compression and compression + torsion) can both remarkably increase the hardness of IF steel disks. Microstructure investigation results can give a well support to verify the rules of hardness distribution, showing hardly no change of grains in center and sever plastic deformation in edge. The inhomogeneous distribution of stress and strain with the huge friction between anvil and disks in the process of HPT play an important role of hardness and microstructure distribution.
基金supported by the National Key Research and Development Program of China(Nos.2020YFA0714700 and 2018YFA0208402)the National Natural Science Foundation of China(Nos.51820105002,51872320,51472264,11634014,and 52172060)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33030100)the Key Research Program of Frontier Sciences,CAS(No.QYZDBSSW-SYS028)the Youth Innovation Promotion Association of CAS(No.2020005).
文摘The heterojunction of single-wall carbon nanotubes(SWCNTs)and perovskite quantum dots(QDs)shows excellent photodetection performances due to the combination of the advantages of high carrier mobility of SWCNTs and high absorption coefficient of perovskite QDs.However,the band structure of a SWCNT is determined by its atomic arrangement structure.How the structure of SWCNTs affects the photoelectric performance of the composite film remains elusive.Here,we systematically explored the diameter effect of SWCNTs with different bandgaps on the photodetection performances of SWCNTs/perovskite QDs heterojunction films by integrating semiconducting SWCNTs(s-SWCNTs)with different diameters with CsPbBr3 QDs.The results show that with an increase in diameter of s-SWCNTs,the heterojunction exhibits increasing responsivity(R),detectivity(D*),and faster response time.The great improvement in the optoelectronic performances of devices should be attributed to the higher carrier mobility of larger-diameter SWCNT films and the increasing built-in electric field at the heterojunction interfaces between larger-diameter SWCNTs and CsPbBr3 QDs,which enhances the separation of the photogenerated excitons and the transport of the resulted carriers in SWCNT films.
基金supported by the National Natural Science Foundation of China(Grant Nos.41930759,42325502)the West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202215)+2 种基金the Chinese Academy Sciences Talents Program,National Cryosphere Desert Data Centerthe Qinghai Key Laboratory of Disaster Prevention(Grant No.QFZ-2021-Z02)2023 First Batch of Science and Technology Plan Projects of Lanzhou City(Grant No.2023-1-49)。
文摘Hydrological modeling,leveraging mathematical formulations to represent the hydrological cycle,is a pivotal tool in representing the spatiotemporal dynamics and distribution patterns inherent in hydrology.These models serve a dual purpose:they validate theoretical robustness and applicability via observational data and project future trends,thereby bridging the understanding and prediction of natural processes.In rapid advancements in computational methodologies and the continuous evolution of observational and experimental techniques,the development of numerical hydrological models based on physicallybased surface-subsurface process coupling have accelerated.Anchored in micro-scale conservation principles and physical equations,these models employ numerical techniques to integrate surface and subsurface hydrodynamics,thus replicating the macro-scale hydrological responses of watersheds.Numerical hydrological models have emerged as a leading and predominant trend in hydrological modeling due to their explicit representation of physical processes,heightened by their spatiotemporal resolution and reliance on interdisciplinary integration.This article focuses on the theoretical foundation of surface-subsurface numerical hydrological models.It includes a comparative and analytical discussion of leading numerical hydrological models,encompassing model architecture,numerical solution strategies,spatial representation,and coupling algorithms.Additionally,this paper contrasts these models with traditional hydrological models,thereby delineating the relative merits,drawbacks,and future directions of numerical hydrological modeling.
基金supported by the National Natural Science Foundation of China(41,977,274,42,130,710)Shaanxi Province Science and Technology Innovation Team(2022TD-09)+1 种基金the Key Industrial Chain Project of Shaanxi Province(2019ZDLNY01-05-022022ZDLNY02-02).
文摘Crop residue-based biochar(CRB)has shown great potential for removing trace elements(TEs)from aquatic matrices.Despite the increasing interest in this area,no review has focused specifically on the efficacy of CRB for TEs removal in aquatic environments.This comprehensive review examines the global TEs water contamination status with an emphasis on their sources,compositional metrics for crop residue feedstock(proximate,ultimate,and lignocellulosic properties),and the potential use of CRB for TEs removal in aquatic media.It also evaluates the factors that affect the ability of CRB to remove TEs,such as feedstock type,production conditions,water pH,background electrolytes,water temperature,CRB/water ratio,and underlying pollutant sorption mechanisms.This review also discusses the practical applications of CRB in real water samples and engineering considerations for designing CRB with improved physicochemical properties,treatment efficiencies,and regeneration abilities.Additionally,the cost-benefit and economic assessment of CRB,challenges,and future research directions related to CRB are highlighted to promote research on this sustainable source of biochar.By elucidating the prospects of CRB as an adsorbent,this review emphasizes the need for continued research on its practical implications for environmentally relevant pollutant concentrations.
