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A novel microwave absorption and dielectric spectrum detection technology in photoelectron dynamic study for solar cells

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Rare Metals 2006年第z1期25卷 153-157页

作者： LI Xiaowei SUN Shuxu LAI Weidong ZHANG Rongxiang dai Xiuhong jiang Xiaoli College of Physics Science & Technology Hebei University Baoding 071002 China College of Physics Science & Technology Hebei University Baoding 071002 China College of Physics Science & Technology Hebei University Baoding 071002 China College of Physics Science & Technology Hebei University Baoding 071002 China College of Physics Science & Technology Hebei University Baoding 071002 China College of Physics Science & Technology Hebei University Baoding 071002 China

The photoelectron property is directly related to the light-energy conversion efficiency of solar cells. In this paper, the photoelectron dynamic of semiconductor was analyzed. The diffusion of electrons has influence on the dielectric function of the solar cell material. And the amplitude variance of the imaginary and real part of the dielectric function is in direct proportion to the dynamic process of free and shallow-trapped electrons. Based on the untouched detection technique, the method is present to detect the amplitude change of the microwave signal which is passing through the material whose dielectric function changes after exposure. A 35 GHz oscillator was used as a microwave source. The absorption and dispersion microwave signals, which contain the dynamic information of free and shallow-trapped electron signal, are split respectively with phase-sensitive instrument. The photoelectron character of n-type Si(100) thin film was investigated by the novel equipment, and the lifetime of different kinds of electrons with the resolution of 1 ns was obtained. The equipment can be directly used in the study of the optoelectronic conversion mechanism of solar cells.

关键词： dye sensitization solar cells microwave absorption dielectric spectrum

Effects of soil shrinkage in permanent gullies formation: The case of Benggang erosion in the granite area of southern China

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Journal of Mountain Science 2021年第9期18卷 2328-2344页

作者： HUANG Wan-xia DENG Yu-song CAI Chong-fa jiang dai-hua Forestry College Guangxi UniversityNanning 530004China Resources and Environment College Huazhong Agricultural UniversityWuhan 430070China Agricultural College Guangxi UniversityNanning 530004China

Soil shrinkage is an important factor in slope destabilization in granitic areas, which is also one of the most important conditions for the formation of permanent gullies. This study explored the effect of soil shrinkage on permanent gullies, and Benggang erosion in granitic areas in southeastern China was used as an example. Three types of Benggang in granitic area were selected to examine the soil shrinkage of three soil layers(the lateritic, transitional and sandy layers) and their effect on the development of Benggang erosion was studied. The results show that the maximum values of COLEH and COLEV(coefficient of linear extensibility in horizontal and vertical directions, respectively) are 3.09% and 1.60% in the laterite layers, 2.71% and 2.13% in transition layers, and 1.10% and 1.82% in sandy layers, indicating that the shrinkage potential of the soil layers exhibits the following order, from highest to lowest: the laterite layer, transition layer, and sandy layer. With a decreasing volumetric water content, the linear shrinkage ratio increases gradually and eventually stabilizes, and in the laterite, transition and sandy layers, the average values of the maximum linear shrinkage are 1.50%, 2.09%, and 1.74%, respectively. Axial shrinkage is most obvious in the transition layers, in which the volume change in the form of subsidence is greater than that in other layers. The soil shrinkage curves fit the trilinear model(R2>0.9), and the soil shrinkage characteristic curves were divided into structural, basic, and residual sections. The correlation analysis shows that the soil shrinkage rate is positively correlated with clay and Fe2 O3 content and negatively correlated with sand content. Clay and sand contents are the most important factors influencing soil shrinkage. Soil oxides can influence soil shrinkage by affecting the particle composition of the soil, so soil shrinkage is closely related to soil clay minerals. Our findings can provide a theoretical basis f

关键词： Soil shrinkage Permanent gully Granite Benggang Soil layers

Direct numerical simulation on relevance of fluctuating velocities and drag reduction in turbulent channel flow with spanwise space-dependent electromagnetic force

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Chinese Physics B 2019年第5期28卷 166-174页

作者： dai-Wen jiang Hui Zhang Bao-Chun Fan An-Hua Wang Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology

Based on the Fourier–Chebyshev spectral method, the control of turbulent channel flow by space-dependent electromagnetic force and the mechanism of drag reduction are investigated with direct numerical simulation(DNS) methods for different Reynolds numbers. A formula is derived to express the relation between fluctuating velocities and the friction drag coefficient. With the application of electromagnetic force, the in-depth relations among the fluctuating velocities near the wall, Reynolds stress, and the effect of drag reduction for different Reynolds numbers are discussed. The results indicate that the maximum drag reductions can be obtained with an optimal combination of parameters for each case of different Reynolds numbers. The fluctuating velocities along the streamwise and normal directions are suppressed significantly,while the fluctuating velocity along the spanwise direction is enhanced dramatically due to the spanwise electromagnetic force. However, the values of Reynolds stress depend on the fluctuating velocities along the streamwise and normal directions rather than that along the spanwise direction. Therefore, the significant effect of drag reduction is obtained. Moreover,the maximum drag reduction is weakened due to the decay of control effect for fluctuating velocities as the Reynolds number increases.

关键词： flow control turbulent channel flow electromagnetic force direct numerical simulation

A facile approach towards high-performance poly(thioether-thioester)s with full recyclability

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Science China Chemistry 2023年第1期66卷 251-258页

作者： jiang dai Wei Xiong Mu-Rong Du Gang Wu Zhongzheng Cai Jian-Bo Zhu National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan) College of ChemistrySichuan UniversityChengdu 610064China

Developing new chemically recyclable polymers is important for a circular plastics ***,we prepared a class of 1,4-dithian-2-one(DTO)with thioether and thioester *** sulfur-substituted monomers(DTO)showed excellent reactivity for ring-opening polymerization(turnover frequency(TOF)up to 2.3×10^(4)h^(-1)),which afforded poly(thioetherthioester)s(P(DTO)s)with high air stability,high crystallinity,and commercial high-density polyethylene-like mechanical property(σB=29.59±1.08 MPa andεB=749%±36%).Intriguingly,chemical recycling of P(DTO)to monomer could be accomplished with excellent efficiency in dilute solution(1 min)at room temperature or even from a commodity plastic waste mixture under catalyst-free thermal bulk condition(180°C),thus establishing its circular life cycle.P(Me-DTO)could be applied for selective removal of Hg^(2+)with>99%removal *** importantly,Me-DTO could be recovered in high yield after utilization for Hg^(2+)adsorption.

关键词： chemically recyclable polymer plastic polythioester ring-opening polymerization mercury adsorption

Well-controlled Organocatalytic Ring-opening Polymerization of Seven-membered Cyclic Carbonates with Cyclohexyl Fusion

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Chemical Research in Chinese Universities 2024年第5期40卷 856-862页

作者： ZHANG Wei SHAN Si-Yi dai jiang CAI Zhongzheng ZHU Jian-Bo Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-utilization College of Chemical Engineering and Materials ScienceTianjin University of Science and TechnologyTianjin300457P.R.China National Engineering Laboratory of Eco-friendly Polymeric Materials(Sichuan) College of ChemistrySichuan UniversityChengdu610064P.R.China

Developing green and well-controlled polymerization methods is of great significance for the preparation of biomedical polymer *** this contribution,an efficient organocatalytic ring-opening polymerization(ROP)of a class of seven-membered cyclic carbonates(T6DO,T6HDO,C6DO,C6HDO)containing cis-or trans-cyclohexane structure was *** catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene(TBD)promoted living polymerization of these cyclic carbonates to deliver polycarbonate and block copolymer products with predictable molecular weights and narrow *** robust TBD-mediated ROP at 90°C showcased turnover frequency(TOF)up to 10^(3)h^(−1).The resulting amorphous polycarbonates displayed good thermal stability.

关键词： CO_(2) Organic catalyst Living ring-opening polymerization Aliphatic polycarbonate

In-situ observation on the deformation behaviors of Fe-Mn-C TWIP steel

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International Journal of Minerals,Metallurgy and Materials 2009年第6期16卷 646-649页

作者： Zhen-li Mi Di Tang Yong-juan dai Hai-tao jiang Jian-chong Lu National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing Beijing 100083 China

The microstructure and crack behaviour of twinning induced plasticity （TWIP） steel during tensile deformation was investigated with in-situ scanning electron microscopy （SEM）. The results show that there are two modes of plastic deformation during tensile test in the Fe-Mn-C TWIP steel： dislocation gliding and deformation twins. During the process of tensile deformation, secondary deformed twins are found. Inclusions have played a role in the course of ductile fracture, and microcracks initiate from inclusions and twin-twin intersections.

关键词： TWIP steel in-situ observation deformation microstructure twinning induced plasticity

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广域确定性网络传输技术综述

软件学报 2025年第1期36卷 371-398页

作者：李彤徐都玲吴波郭雄文蒋岱均罗成卢卫杜小勇数据工程与知识工程教育部重点实验室(中国人民大学) 中国人民大学信息学院腾讯科技有限公司

广域网作为连接新业务、新基础设施和各类新型应用的纽带,已成为21世纪最重要的基础设施之一.近年来,数据量爆炸性增长,伴随着基于广域网的大模型、数字经济、元宇宙和全息社会等新型应用形态的持续涌现,以及东数西算、算力网络和数据... 详细信息

广域网作为连接新业务、新基础设施和各类新型应用的纽带,已成为21世纪最重要的基础设施之一.近年来,数据量爆炸性增长,伴随着基于广域网的大模型、数字经济、元宇宙和全息社会等新型应用形态的持续涌现,以及东数西算、算力网络和数据场等新型业务架构的出现,业务对广域网的数据传输服务质量提出了越来越高的要求.以时延为例,广域网不仅需要提供及时的服务,还需要提供准时的服务,即时延成为必须满足的确定性指标.因此,广域确定性网络作为广域网的新范式应运而生.系统地综述确定性网络的内涵,回顾传统确定性网络相关技术发展脉络,介绍广域确定性网络的新应用,探讨广域网确定性网络传输具有的新特征以及面临的新挑战,并提出广域确定性网络的新目标.基于上述新应用、新特征、新挑战和新目标,详细总结当前广域确定性网络领域的主要研究进展,并给出未来研究的方向.期望能为广域确定性网络领域的研究提供参考和帮助.

关键词：广域网确定性网络数据传输改良式革命式

Amplification of plasmid DNA bound on soil colloidal particles and clay minerals by the polymerase chain reaction

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Journal of Environmental Sciences 2007年第11期19卷 1326-1329页

作者： CAI Peng HUANG Qiao-yun LU Yan-du CHEN Wen-li jiang dai-hua LIANG Wei State Key Laboratory of Agricultural Microbiology Huazhong Agricultural University Wuhan 430070 China Key Laboratory of Subtropical Agricultural Resources a~ld Environment Huazhong Agricultural University Wuhan 430070 China

Polymerase chain reaction （PCR） was used to amplify a 600-base pair （bp） sequence of plasmid pGEX-2T DNA bound on soil colloidal particles from Brown soil （Alfisol） and Red soil （Ultisol）, and three different minerals （goethite, kaolinite, montmorillonite）. DNA bound on soil colloids, kaolinite, and montmorillonite was not amplified when the complexes were used directly but amplification occurred when the soil colloid or kaolinite-DNA complex was diluted, 10- and 20-fold. The montmorillonite-DNA complex required at least 100-fold dilution before amplification could be detected. DNA bound on goethite was amplified irrespective of whether the complex was used directly, or diluted 10- and 20-fold. The amplification of mineral-bound plasmid DNA by PCR is, therefore, markedly influenced by the type and concentration of minerals used. This information is of fundamental importance to soil molecular microbial ecology with particular reference to monitoring the fate of genetically engineered microorganisms and their recombinant DNA in soil environments.

关键词： adsorption amplification mineral PCR plasmid DNA soil colloid

Isothermal Microcalorimetry:A Review of Applications in Soil and Environmental Sciences

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Pedosphere 2007年第2期17卷 137-145页

作者： RONG Xing-Min HUANG Qiao-Yun jiang dai-Hua CAI Peng LIANG Wei Key Laboratory of Subtropical Agricultural Resources and Environment Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 （China）

Isothermal microcalorimetry provides thermodynamic and kinetic information on various reactions and processes and is thereby a powerful tool to elucidate their mechanisms. Certain improvement in isothermal microcalorimetry with regard to the studies on soil and environmental sciences is briefly described. This review mainly focuses on the use of microcalorimetry in the determination of soil microbial activity, monitoring the toxicity and biodegradation of soil organic pollutants, the risk evaluation of metals and metalloids, the heat effect of ion exchange and adsorption in soil, and environmental researches. Promising prospects for the applications of the technique in the field are also discussed.

关键词： environment isothermal microbial activity microcalorimetry soil