Four numerical schemes are introduced for the analysis of photocurrent transients in organic photovoltaic devices.Themathematicalmodel for organic polymer solar cells contains a nonlinear diffusion-reaction partial di...Four numerical schemes are introduced for the analysis of photocurrent transients in organic photovoltaic devices.Themathematicalmodel for organic polymer solar cells contains a nonlinear diffusion-reaction partial differential equation system with electrostatic convection attached to a kinetic ordinary differential equation.To solve the problem,Polynomial-based differential quadrature,Sinc,and Discrete singular convolution are combined with block marching techniques.These schemes are employed to reduce the problem to a nonlinear algebraic system.The iterative quadrature technique is used to solve the reduced problem.The obtained results agreed with the previous exact one and the finite element method.Further,the effects of different times,different mobilities,different densities,different geminate pair distances,different geminate recombination rate constants,different generation efficiencies,and supporting conditions on photocurrent have been analyzed.The novelty of this paper is that these schemes for photocurrent transients in organic polymer solar cells have never been presented before,so the results may be useful for improving the performance of solar cells.展开更多
The research in the genetics of sex determination and the differentiation of reproductive organs in flowering plants has long been a topic in recent years. Understanding the genetic and molecular mechanisms that contr...The research in the genetics of sex determination and the differentiation of reproductive organs in flowering plants has long been a topic in recent years. Understanding the genetic and molecular mechanisms that control sex determination in flower- ing plants relies on detailed studies of the differentiation of sexual organs. Current theories about sex chromosomes have illuminated the mechanisms of plant sex determination. In addition, recent progress in cloning floral homeotic genes which regulate the identity of the floral organs has generated molecular markers to compare the developmental programs of male, female and hermaphrodite flowers in several species. In this review, the authors focus attention on these recent findings and provide a brief overview of the genetics of plant sex determination and the mechanism of sex determination gene expression and gene programs.展开更多
A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the wo...A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the working conditions of differential pulse voltammetry (d.p. v.) for determining the organic reducing substances produced during the processes of the anaerobic decomposition of plant materials were established with a glass carbon electrode as working electrode, 1 M Ag-AgCl electrode with large area as reference electrode, 0.2 M NH4AC as supporting electrolyte and pH buffer solution, pulse amplitude (AE) of 25 mV, scan rate at 2 mV·S-1and scan potential ranging from -0.5 to +1.2 voltage(vs. M Ag-AgCl). The peak current proportional to the concentration of reducing substances, and the characteristic peak potential of each organic reducing substance were regarded as the quantitative and qualitative base, respectively. These results obtained under the conditions mentioned above directly reflect both the reducing intensity and capacity of the organic reducing system in soils.展开更多
Room-temperature negative differential resistance （NDR） has been observed in different types of organic materials. However, detailed study on the influence of the organic material on NDR performance is still scarce....Room-temperature negative differential resistance （NDR） has been observed in different types of organic materials. However, detailed study on the influence of the organic material on NDR performance is still scarce. In this work, room-temperature NDR ＆ observed when CdSe quantum dot （QD） modified ITO is used as the electrode. Furthermore, material dependence of the NDR performance is observed by selecting materials with different charge transporting properties as the active layer, respectively. A peak-to-valley current ratio up to 9 is observed. It is demonstrated that the injection barrier between ITO and the organic active layer plays a decisive role for the device NDR performance. The influence of the aggregation state of CdSe QDs on the NDR performance is also studied, which indicates that the NDR is caused by the resonant tunneling process in the ITO/CdSe QD/organic active layer structure.展开更多
Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and sexuality.The detailed regulatory mechanisms underlying these changes still remain larg...Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and sexuality.The detailed regulatory mechanisms underlying these changes still remain largely unclear.In this study,through analyzing the time-course meristem transcriptomes and floret single-cell transcriptomes of ear and tassel,we revealed the regulatory dynamics and pathways underlying inflorescence development and sex differentiation.We identified 16 diverse gene clusters with differential spatiotemporal expression patterns and revealed biased regulation of redox,programmed cell death,and hormone signals during meristem differentiation between ear and tassel.Notably,based on their dynamic expression patterns,we revealed the roles of two RNA-binding proteins in regulating inflorescence meristem activity and axillary meristem formation.Moreover,using the transcriptional profiles of 53910 single cells,we uncovered the cellular heterogeneity between ear and tassel florets.We found that multiple signals associatedwith either enhancedcell death or reduced growth are responsiblefortassel pistil suppression,while part of the gibberellic acid signal may act non-cell-autonomously to regulate ear stamen arrest during sex differentiation.We further showed that the pistil-protection gene SILKLESS 1(SK1)functions antagonistically to the known pistil-suppression genes through regulating common molecular pathways,and constructed a regulatory network for pistil-fate determination.Collectively,our study provides a deep understanding of the regulatory mechanisms underlying inflorescence development and sex differentiation in maize,laying the foundation for identifying new regulators and pathways for maize hybrid breeding and improvement.展开更多
文摘Four numerical schemes are introduced for the analysis of photocurrent transients in organic photovoltaic devices.Themathematicalmodel for organic polymer solar cells contains a nonlinear diffusion-reaction partial differential equation system with electrostatic convection attached to a kinetic ordinary differential equation.To solve the problem,Polynomial-based differential quadrature,Sinc,and Discrete singular convolution are combined with block marching techniques.These schemes are employed to reduce the problem to a nonlinear algebraic system.The iterative quadrature technique is used to solve the reduced problem.The obtained results agreed with the previous exact one and the finite element method.Further,the effects of different times,different mobilities,different densities,different geminate pair distances,different geminate recombination rate constants,different generation efficiencies,and supporting conditions on photocurrent have been analyzed.The novelty of this paper is that these schemes for photocurrent transients in organic polymer solar cells have never been presented before,so the results may be useful for improving the performance of solar cells.
文摘The research in the genetics of sex determination and the differentiation of reproductive organs in flowering plants has long been a topic in recent years. Understanding the genetic and molecular mechanisms that control sex determination in flower- ing plants relies on detailed studies of the differentiation of sexual organs. Current theories about sex chromosomes have illuminated the mechanisms of plant sex determination. In addition, recent progress in cloning floral homeotic genes which regulate the identity of the floral organs has generated molecular markers to compare the developmental programs of male, female and hermaphrodite flowers in several species. In this review, the authors focus attention on these recent findings and provide a brief overview of the genetics of plant sex determination and the mechanism of sex determination gene expression and gene programs.
文摘A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the working conditions of differential pulse voltammetry (d.p. v.) for determining the organic reducing substances produced during the processes of the anaerobic decomposition of plant materials were established with a glass carbon electrode as working electrode, 1 M Ag-AgCl electrode with large area as reference electrode, 0.2 M NH4AC as supporting electrolyte and pH buffer solution, pulse amplitude (AE) of 25 mV, scan rate at 2 mV·S-1and scan potential ranging from -0.5 to +1.2 voltage(vs. M Ag-AgCl). The peak current proportional to the concentration of reducing substances, and the characteristic peak potential of each organic reducing substance were regarded as the quantitative and qualitative base, respectively. These results obtained under the conditions mentioned above directly reflect both the reducing intensity and capacity of the organic reducing system in soils.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61106123 and 61275034the National Basic Research Program of China under Grant No 2013CB328705
文摘Room-temperature negative differential resistance （NDR） has been observed in different types of organic materials. However, detailed study on the influence of the organic material on NDR performance is still scarce. In this work, room-temperature NDR ＆ observed when CdSe quantum dot （QD） modified ITO is used as the electrode. Furthermore, material dependence of the NDR performance is observed by selecting materials with different charge transporting properties as the active layer, respectively. A peak-to-valley current ratio up to 9 is observed. It is demonstrated that the injection barrier between ITO and the organic active layer plays a decisive role for the device NDR performance. The influence of the aggregation state of CdSe QDs on the NDR performance is also studied, which indicates that the NDR is caused by the resonant tunneling process in the ITO/CdSe QD/organic active layer structure.
基金the National Natural Science Foundation of China(32172026,U22A20460 to F.Y.)the Interdisciplinary Sciences Research Institute(2662021JC005 to F.Y.)111 Project Crop genomics and Molecular Breeding(B20051 to F.Y.).
文摘Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and sexuality.The detailed regulatory mechanisms underlying these changes still remain largely unclear.In this study,through analyzing the time-course meristem transcriptomes and floret single-cell transcriptomes of ear and tassel,we revealed the regulatory dynamics and pathways underlying inflorescence development and sex differentiation.We identified 16 diverse gene clusters with differential spatiotemporal expression patterns and revealed biased regulation of redox,programmed cell death,and hormone signals during meristem differentiation between ear and tassel.Notably,based on their dynamic expression patterns,we revealed the roles of two RNA-binding proteins in regulating inflorescence meristem activity and axillary meristem formation.Moreover,using the transcriptional profiles of 53910 single cells,we uncovered the cellular heterogeneity between ear and tassel florets.We found that multiple signals associatedwith either enhancedcell death or reduced growth are responsiblefortassel pistil suppression,while part of the gibberellic acid signal may act non-cell-autonomously to regulate ear stamen arrest during sex differentiation.We further showed that the pistil-protection gene SILKLESS 1(SK1)functions antagonistically to the known pistil-suppression genes through regulating common molecular pathways,and constructed a regulatory network for pistil-fate determination.Collectively,our study provides a deep understanding of the regulatory mechanisms underlying inflorescence development and sex differentiation in maize,laying the foundation for identifying new regulators and pathways for maize hybrid breeding and improvement.
