In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor film...In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.展开更多
The finite element equations considering the geometrical nonlinearity of piezoelectric smart structures are derived based on the total Lagrange method under the assumption of weak coupling between electricity and mech...The finite element equations considering the geometrical nonlinearity of piezoelectric smart structures are derived based on the total Lagrange method under the assumption of weak coupling between electricity and mechanics. Buckling and post-buckling of piezoelectric-plate with various boundary conditions are investigated. The calculated results show that piezoelectric effects and external voltage can hardly affect the buckling and post-bucking characteristics of piezoelectric-plate under uniaxial pressure while the buckling caused by displacement in-plane has much to do with the electric field.展开更多
Over the past decades,the research in ELT methods has already experienced an ongoing transition from method-based pedagogy to post-method pedagogy.With regard to various method-based pedagogy,which is the best and app...Over the past decades,the research in ELT methods has already experienced an ongoing transition from method-based pedagogy to post-method pedagogy.With regard to various method-based pedagogy,which is the best and appropriate method for TEFL in China has been still a controversial and vital issue.By the reflection and critical analysis of my own experience as an EFL learner and of teaching methods and principles in ELT class as a college teacher,this paper mainly demonstrates there is no one so called‘best’or‘right’teaching methods for all from the perspective of Post-method framework which reflects a theoretical construct for teachers to effectively develop a systematic,and coherent pedagogy in their teaching context,aims to provide more instructive reference for ELT and English teachers’development in China.展开更多
The equivalent filter modeling of a rectangular dielectric post in a rectangular waveguide is obtained through the variational expression of input impedance. The reflection coefficient expressed in components of netwo...The equivalent filter modeling of a rectangular dielectric post in a rectangular waveguide is obtained through the variational expression of input impedance. The reflection coefficient expressed in components of network is in good agreement with the results given by K. Siakavara, et al. (1991), The method can be applied to design filter.展开更多
<strong>Background:</strong> Self-management is important for post-renal transplant recipients to resolve renal dysfunction, heart failure, and post-transplant psychosocial issues, and to maintain transpla...<strong>Background:</strong> Self-management is important for post-renal transplant recipients to resolve renal dysfunction, heart failure, and post-transplant psychosocial issues, and to maintain transplant kidney function, etc. However, because recipients may be unable to adequately self-manage, healthcare providers need to provide self-management support for recipients to improve their skills and confidence in managing their disease. However, it is difficult to comprehensively assess the self-management behaviors in a busy outpatient support setting. Furthermore, since there are no uniform standards for assessment, it is based on the experience and abilities of medical personnel. Therefore, self-management behavior of post-renal transplant recipients is not sufficiently evaluated. <strong>Objective:</strong> This study aimed to evaluate content validity of a tool that can assess self-management behaviors of adult post-renal transplant recipients, consisting of consensus components from experts familiar with the follow-up of adult post-renal transplant recipients. <strong>Methods:</strong> A three-round modified Delphi method was used to assess the self-management behaviors of adult post-renal transplant recipients by a panel of experts consisting of certified transplant recipient coordinators, physicians, outpatient nurses, and researchers familiar with the follow-up of post-renal transplant recipients. Regarding management behaviors of adult post-renal transplant recipients, the experts rated the appropriateness and validity of each item using a Likert scale. Consensus ratings from the experts were made by calculating the median, interquartile range, and interquartile range percentage. In the third round, an item-level content validity index was calculated to assess content validity. <strong>Conclusions: </strong>The 41-item self-management behavior scale for kidney transplant recipients assessed self-management behaviors in five domains: medication, exercise, fluids and diet, disease and symptom prevention and management, and psychosocial adjustment. The content validity of this tool was confirmed, and it can be used to more easily assess the recipients’ self-management behaviors in the post-renal transplant follow-up. This tool can potentially contribute to the maintenance of transplant kidney function and high QOL in recipients.展开更多
Based on the multi-rigid body discretization model, namely, finite segment model,a chain multi-rigid-body-hinge-spring system model of a beam was presented, then a nonlinear parametrically exacted vibration equation o...Based on the multi-rigid body discretization model, namely, finite segment model,a chain multi-rigid-body-hinge-spring system model of a beam was presented, then a nonlinear parametrically exacted vibration equation of multi-degrees of freedom system was established using the coordination transformation method, and its resonance fields were derived by the restriction parameter method, that is, the dynamical buckling analysis of the beam. Because the deformation of a beam is not restricted by the discrete model and dynamic equation, the post buckling analysis can be done in above math model. The numerical solutions of a few examples were obtained by direct integrated method, which shows that the mechanical and math model gotten is correct.展开更多
On the basis of the general theory of perforated thin plates under large deflections, variational principles with deflection w and stress function F as variables are stated in detail.Based on these princi- ples,finite...On the basis of the general theory of perforated thin plates under large deflections, variational principles with deflection w and stress function F as variables are stated in detail.Based on these princi- ples,finite element method is established for analysing the buckling and post-buckling of perforated thin plates. It is found that the property of element is very complicated,owing to the multiple connexity of the region.展开更多
金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的...金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的荧光传感材料。本文以3,5-二(4-咪唑-1-基)吡啶(Bip)为主配体,1,4-萘二甲酸(1,4-ndc)为辅助配体,Ni^(2+)为中心离子,采取溶剂热法合成了一例二维金属有机框架[Ni_(2)(Bip)_(2)(1,4-ndc)_(2)(H_(2)O)_(6)](记为CUST-756,其中CUST是Changchun University of Science and Technology缩写),并通过合成后修饰法制备了Eu^(3+)@CUST-756复合发光材料。利用XRD、FT-IR和XPS对合成的CUST-756和Eu^(3+)@CUST-756复合材料进行了基础表征。并且采用荧光光谱对样品进行了发光特性、金属离子传感性能及其机理研究。实验结果表明,Eu^(3+)@CUST-756在甲醇溶液中具备优异的发光性能和良好的稳定性,Eu^(3+)的引入使得材料可用于金属阳离子Cr^(3+)、Fe^(3+)检测。Cr^(3+)离子的检出限(limit of detection,LOD)为5.44µmol·L^(-1);Fe^(3+)离子的LOD为7.51µmol·L^(-1),与大多数LMOFs性能相近。展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51421002, 51627803, 91733301, 51761145042, 21501183, 51402348, 53872321, and 11874402)the Knowledge Innovation Program and the Strategic Priority Research Program (Grant XDB 12010400) of the Chinese Academy of Sciences
文摘In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.
基金the National Natural Science Foundation of China(No.59635140)
文摘The finite element equations considering the geometrical nonlinearity of piezoelectric smart structures are derived based on the total Lagrange method under the assumption of weak coupling between electricity and mechanics. Buckling and post-buckling of piezoelectric-plate with various boundary conditions are investigated. The calculated results show that piezoelectric effects and external voltage can hardly affect the buckling and post-bucking characteristics of piezoelectric-plate under uniaxial pressure while the buckling caused by displacement in-plane has much to do with the electric field.
文摘Over the past decades,the research in ELT methods has already experienced an ongoing transition from method-based pedagogy to post-method pedagogy.With regard to various method-based pedagogy,which is the best and appropriate method for TEFL in China has been still a controversial and vital issue.By the reflection and critical analysis of my own experience as an EFL learner and of teaching methods and principles in ELT class as a college teacher,this paper mainly demonstrates there is no one so called‘best’or‘right’teaching methods for all from the perspective of Post-method framework which reflects a theoretical construct for teachers to effectively develop a systematic,and coherent pedagogy in their teaching context,aims to provide more instructive reference for ELT and English teachers’development in China.
文摘The equivalent filter modeling of a rectangular dielectric post in a rectangular waveguide is obtained through the variational expression of input impedance. The reflection coefficient expressed in components of network is in good agreement with the results given by K. Siakavara, et al. (1991), The method can be applied to design filter.
文摘<strong>Background:</strong> Self-management is important for post-renal transplant recipients to resolve renal dysfunction, heart failure, and post-transplant psychosocial issues, and to maintain transplant kidney function, etc. However, because recipients may be unable to adequately self-manage, healthcare providers need to provide self-management support for recipients to improve their skills and confidence in managing their disease. However, it is difficult to comprehensively assess the self-management behaviors in a busy outpatient support setting. Furthermore, since there are no uniform standards for assessment, it is based on the experience and abilities of medical personnel. Therefore, self-management behavior of post-renal transplant recipients is not sufficiently evaluated. <strong>Objective:</strong> This study aimed to evaluate content validity of a tool that can assess self-management behaviors of adult post-renal transplant recipients, consisting of consensus components from experts familiar with the follow-up of adult post-renal transplant recipients. <strong>Methods:</strong> A three-round modified Delphi method was used to assess the self-management behaviors of adult post-renal transplant recipients by a panel of experts consisting of certified transplant recipient coordinators, physicians, outpatient nurses, and researchers familiar with the follow-up of post-renal transplant recipients. Regarding management behaviors of adult post-renal transplant recipients, the experts rated the appropriateness and validity of each item using a Likert scale. Consensus ratings from the experts were made by calculating the median, interquartile range, and interquartile range percentage. In the third round, an item-level content validity index was calculated to assess content validity. <strong>Conclusions: </strong>The 41-item self-management behavior scale for kidney transplant recipients assessed self-management behaviors in five domains: medication, exercise, fluids and diet, disease and symptom prevention and management, and psychosocial adjustment. The content validity of this tool was confirmed, and it can be used to more easily assess the recipients’ self-management behaviors in the post-renal transplant follow-up. This tool can potentially contribute to the maintenance of transplant kidney function and high QOL in recipients.
文摘Based on the multi-rigid body discretization model, namely, finite segment model,a chain multi-rigid-body-hinge-spring system model of a beam was presented, then a nonlinear parametrically exacted vibration equation of multi-degrees of freedom system was established using the coordination transformation method, and its resonance fields were derived by the restriction parameter method, that is, the dynamical buckling analysis of the beam. Because the deformation of a beam is not restricted by the discrete model and dynamic equation, the post buckling analysis can be done in above math model. The numerical solutions of a few examples were obtained by direct integrated method, which shows that the mechanical and math model gotten is correct.
基金Project supported by National Natural Science Foundation of China.
文摘On the basis of the general theory of perforated thin plates under large deflections, variational principles with deflection w and stress function F as variables are stated in detail.Based on these princi- ples,finite element method is established for analysing the buckling and post-buckling of perforated thin plates. It is found that the property of element is very complicated,owing to the multiple connexity of the region.
文摘金属离子过量使用会造成环境污染,危及人类健康。因此,对相关金属离子进行检测显得尤为重要。发光金属有机框架(Luminescent metal-organic frameworks,LMOFs)因其具备高色纯度、超高孔隙率和可调结构等优势,被视为简单有效且有前途的荧光传感材料。本文以3,5-二(4-咪唑-1-基)吡啶(Bip)为主配体,1,4-萘二甲酸(1,4-ndc)为辅助配体,Ni^(2+)为中心离子,采取溶剂热法合成了一例二维金属有机框架[Ni_(2)(Bip)_(2)(1,4-ndc)_(2)(H_(2)O)_(6)](记为CUST-756,其中CUST是Changchun University of Science and Technology缩写),并通过合成后修饰法制备了Eu^(3+)@CUST-756复合发光材料。利用XRD、FT-IR和XPS对合成的CUST-756和Eu^(3+)@CUST-756复合材料进行了基础表征。并且采用荧光光谱对样品进行了发光特性、金属离子传感性能及其机理研究。实验结果表明,Eu^(3+)@CUST-756在甲醇溶液中具备优异的发光性能和良好的稳定性,Eu^(3+)的引入使得材料可用于金属阳离子Cr^(3+)、Fe^(3+)检测。Cr^(3+)离子的检出限(limit of detection,LOD)为5.44µmol·L^(-1);Fe^(3+)离子的LOD为7.51µmol·L^(-1),与大多数LMOFs性能相近。
