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Absorption of electromagnetic waves by the dust particles in a plasma

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Science China(Technological Sciences) 2004年第4期47卷 461-469页

作者： li fang li lianlin SUI Qiang Institute of Electronics Chinese Academy of Sciences Beijing 100080 China Institute of Electronics Chinese Academy of Sciences Beijing 100080 China Institute of Electronics Chinese Academy of Sciences Beijing 100080 China

Absorption of electromagnetic waves by the dust particles in a plasma has been studied based on a Mie-Debye scattering mode. The longitudinal field of the Debye scattering has been derived and the wave energy loss from it has been calculated. It is shown that the lower the temperature of the plasma is and the higher the density of the plasma is, the larger the absorption cross section will be due to the longitudinal scattering. For the low frequency waves the electromagnetic waves scattered in a dusty plasma are mainly in the form of Debye scattering. In this case the energy loss due to the longitudinal scattering will affect the wave propagation seriously.

关键词： dusty plasma, Mie-Debye scatter, absorption cross section, total section.

Zero increase in peak discharge for sustainable development

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Frontiers of Environmental Science & Engineering 2017年第4期11卷 11-21页

作者： Xing fang Junqi li Yongwei Gong Xiaoning li Department of Civil Engineering Auburn University Auburn AL 36849-5337 USA Key Laboratory of Urban Stormwater System and Water Environment Ministry of Education Beijing University of Civil Engineering and Architecture Beijing 100044 China

For urban land development, some or all natural land uses （primarily pervious） are converted into impervious areas which lead to increases of runoff volume and peak discharge. Most of the developed countries require a zero increase in peak discharge for any land development, and the policy has been implemented for several decades. The policy of zero increase in peak discharge can be considered as historical and early stage for the low impact development （liD） and sustainable development, which is to maintain natural hydrological conditions by storing a part or all of additional runoff due to the development on site. The paper will discuss the policy, the policy implementation for individual projects and their impact on regional hydrology. The design rainfalls for sizing liD facilities that are determined in 206 weather stations in USA are smaller than design rainfalls for sizing detention *** zero-increase policy links to financial responsibility and sustainability for construction of urban stormwater infrastructures and for reducing urban flooding. The policy was compared with current practices of urban development in China to shine the light for solving urban stormwater problems. The connections and differences among liD practices, the zero-increase policy, and the flood control infrastructure were discussed. We promote and advocate the zero-increase policy on peak discharge for comprehensive stormwater management in China in addition to liD.

关键词： Stormwater management Detention basin Zero increase Peak discharge ' Sustainable development Design rainfall

Solidification structure refinement of ferritic stainless steel based on heterogeneous nucleation technology

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Journal of Iron and Steel Research International 2019年第2期26卷 137-147页

作者： Xiao-fang Shi li-zhong Chang li Zhou School of Metallurgy Engineering Anhui University of TechnologyMa'anshan 243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resources Recycling(Anhui University of Technology) Ministry of EducationMa'anshan 243002AnhuiChina

The ridging defect on the surface of stainless steel products is related to the solidification structure of ferritic stainless *** the solidification structure and increasing the proport io n of equiaxed grains are necessary to lesse n the ridging ***,a new idea of using a heterogeneous nucieating agent which was composed of the composite core containing Ti was proposed,that is,a large amount of dispersed fine particles were initially formed on the solidification front,and a great amount ofδiron was then nucleated using these fine particles as the heterogeneous *** analyzing the crystallographic relationship between different crystals and inducing the calculation formulas of disregistry,the disregistry between the different oxides and TiNδiron was explored and the type of nucleation core was *** key parameters of forming the composite core containing Ti were obtained through a thermodynamic calculatio *** experimental results further con firm the correctness of the theoretical analysis.

关键词： Ferritic stainless steel Structure refinement Disregistry Heterogeneous nucleation Thermodynamics Solidification

Generation of genetically modified mice using CRISPR/Cas9 and haploid embryonic stem cell systems

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Zoological Research 2016年第4期37卷 205-213页

作者： li-fang JIN Jin-Song li College of life Science of Shaoxing University Shaoxing Zhejiang 312000 China State Key Laboratory of Cell Biology CAS Center for Excellence in Molecular Cell Science Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Science Shanghai 200031 China Shanghai Key Laboratory of Molecular Andrology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological SciencesChinese Academy of Science Shanghai 200031 China

With the development of high-throughput sequencing technology in the post-genomic era, researchers have concentrated their efforts on elucidating the relationships between genes and their corresponding functions. Recently, important progress has been achieved in the generation of genetically modified mice based on CRISPR/Cas9 and haploid embryonic stem cell （haESC） approaches, which provide new platforms for gene function analysis, human disease modeling, and gene therapy. Here, we review the CRISPR/Cas9 and haESC technology for the generation of genetically modified mice and discuss the key challenges in the application of these approaches.

关键词： CRISPR/Cas9 Haploid embryonic stem cells Mouse Genetic modification

Process intensification and energy saving of reactive distillation for production of ester compounds

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Chinese Journal of Chemical Engineering 2019年第6期27卷 1307-1323页

作者： Chunli li Cong Duan Jing fang Hongshi li School of Chemical Engineering and Technology Hebei University of TechnologyTianjin 300130China National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization Tianjin 300130China

Reactive distillation(RD) process is an innovative hybrid process combining reaction with distillation, which has recently come into sharp focus as a successful case of process intensification. Considered as the most representative case of process intensification, it has been applied for many productions, especially for production of ester compounds. However, such problems existing in the RD system for ester productions are still hard to solve,as the removal of the water which comes from the esterification, and the separation of the azeotropes of ester–alcohol(–water). Many methods have been studying on the process to solve the problems resulting in further intensification and energy saving. In this paper, azeotropic–reactive distillation or entrainer enhanced reactive distillation(ERD) process, reactive extractive distillation(RED) process, the method of co-production in RD process, pressure-swing reactive distillation(PSRD) process, reactive distillation–pervaporation coupled process(RD–PV), are introduced to solve the problems above, so the product(s) can be separated efficiently and the chemical equilibrium can be shifted. Dividing-wall column(DWC) structure and novel methods of loading catalyst are also introduced as the measures to intensify the process and save energy.

关键词： Reactive distillation Process intensification Process coupling Thermal coupling

复式钢管混凝土墩柱轴压性能及承载力提高分析

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A Double Varying-coefficient Modeling Approach for Analyzing Longitudinal Observations

工程力学 2025年第1期42卷 209-222页

作者：张玉芬郝圣旺李栋磊方永坚燕山大学建筑工程与力学学院秦皇岛066099 河北工业大学土木与交通学院天津300401 河北省土木工程绿色建造与智能运维重点实验室秦皇岛066099

为提升矩形钢管混凝土独柱墩的工作性能，在其截面内套异心双圆钢管形成新型复式钢管混凝土墩柱。该文进行了7个墩柱轴压荷载试验，通过对比空钢管柱、矩形墩柱和夹层墩柱分析了新型墩柱的破坏形态、钢管应变发展及承载力和延性差异，... 详细信息

为提升矩形钢管混凝土独柱墩的工作性能，在其截面内套异心双圆钢管形成新型复式钢管混凝土墩柱。该文进行了7个墩柱轴压荷载试验，通过对比空钢管柱、矩形墩柱和夹层墩柱分析了新型墩柱的破坏形态、钢管应变发展及承载力和延性差异，最后利用钢管和混凝土的组合效应原理进行组合墩柱轴压承载力提高分析。研究得出新型复式钢管混凝土墩柱轴压破坏形态为鼓曲破坏，其极限承载力较夹层墩柱提高20%，较矩形墩柱提高22%，延性提高效果更为明显;新型墩柱内、外钢管应变发展充分，说明钢管较好地发挥了竖向承载和横向约束混凝土的能力;根据钢板的正则化宽厚比和屈曲后强度计算得出，内、外钢管在混凝土的支撑下承载力提高15%，混凝土在钢管的约束下承载力提高49%;根据约束组合效应得出，新型墩柱整体承载力提高31%;采用等效套箍系数计算的新型墩柱承载力与试验值绝对误差在4%以内，说明新型复式钢管混凝土墩柱符合钢管混凝土统一理论。研究结果表明，新型复式钢管混凝土墩柱在约束混凝土效应方面明显提高，构件的承载力较高、延性较好，具有较强的工程应用前景。

关键词：新型复式钢管混凝土墩柱轴压性能破坏形态承载力套箍系数

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Acta Mathematicae Applicatae Sinica 2019年第3期35卷 671-688页

作者： Qun-fang XU Rui li School of Business Ningbo UniversityNingbo 315211China School of Statistics and Information Shanghai University of International Business and EconomicsShanghai 201620China Key Laboratory of Advanced Theory and Application in Statistics and Data Science East China Normal UniversityMinistry of EducationShanghai 200062China

The identification of within-subject dependence is important for constructing efficient estimation in longitudinal data *** this paper,we proposed a flexible way to study this dependence by using nonparametric regression ***,we considered the estimation of varying coefficient longitudinal data model with non-stationary varying coefficient autoregressive error process over observational time *** on spline approximation and local polynomial techniques,we proposed a two-stage nonparametric estimation for unknown functional coefficients and didn’t not drop any observations in a hybrid least square loss ***,we showed that the estimated coefficient functions are asymptotically normal and derived the asymptotic biases and variances *** Carlo studies and two real applications were conducted for illustrating the performance of our proposed methods.

关键词： autoregressive process double varying coefficient irregular time quantum locally linear

Joint resource allocation for hybrid NOMA-assisted MEC in 6G networks

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Digital Communications and Networks 2020年第3期6卷 241-252页

作者： Haodong li fang fang Zhiguo Ding Department of Electrical and Electronic Engineering The University of ManchesterM139PLUK Department of Engineering Durham UniversityDurham DH13LEUK

Multi-access Edge Computing(MEC)is an essential technology for expanding computing power of mobile devices,which can combine the Non-Orthogonal Multiple Access(NOMA)in the power domain to multiplex signals to improve spectral *** study the integration of the MEC with the NOMA to improve the computation service for the Beyond Fifth-Generation(B5G)and the Sixth-Generation(6G)wireless *** paper aims to minimize the energy consumption of a hybrid NOMA-assisted MEC *** a hybrid NOMA system,a user can offload its task during a time slot shared with another user by the NOMA,and then upload the remaining data during an exclusive time duration served by Orthogonal Multiple Access(OMA).The original energy minimization problem is *** efficiently solve it,we first assume that the user grouping is given,and focuses on the one group ***,a multilevel programming method is proposed to solve the non-convex problem by decomposing it into three subproblems,i.e.,power allocation,time slot scheduling,and offloading task assignment,which are solved optimally by carefully studying their convexity and *** derived solution is optimal to the original problem by substituting the closed expressions obtained from those decomposed ***,we investigate the multi-user case,in which a close-to-optimal algorithm with lowcomplexity is proposed to form users into different groups with unique time *** simulation results verify the superior performance of the proposed scheme compared with some benchmarks,such as OMA and pure NOMA.

关键词： Non-orthogonal multiple access(NOMA) Multi-access edge computing(MEC) Resource allocation User grouping Task assignment

Room-temperature ferromagnetism enhancement in Fe-doped VSe2nanosheets synthesized by a chemical method

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Rare Metals 2021年第9期40卷 2501-2507页

作者： li-Yan Hu li-fang Yu Huan Yang Xian Xu fang Wang Xiao-Hong Xu School of Chemistry and Materials Science Shanxi Normal UniversityLinfen 041004China Key Laboratory of Magnetic Molecules and Magnetic Information Materials Ministry of EducationLinfen 041004China Research Institute of Materials Science Shanxi Normal UniversityLinfen 041004China Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and Technology Linfen 041004China

Two-dimensional(2 D)few-layerVSe_(2),V_(1-x)Fe_(x)Se_(2) nanosheets have been synthesized by a hightemperature organic solution-phase method. The thickness of VSe_(2) nanosheets can be tuned from 12 to 5 layers by decreasing the precursor concentrations. The few-layer VSe_(2) nanosheets show the room-temperature ferromagnetism. The coercivity and magnetization reach 0.024 T and 0.036 mA·m^(2)·g^(-1) at room temperature. The chargedensity wave behavior is also confirmed in VSe_(2) by the hysteresis loops and zero-field-cooling curve. V_(1-x)Fe_(x)Se_(2) nanosheets can be obtained by doping Fe(acac)3 in the reaction process. The room-temperature coercivity and magnetization of V_(0.8)Fe_(0.2)Se_(2) nanosheets are 5 times higher than those of the pure VSe_(2) nanosheets without destroying the structures. The enhancement of magnetization is due to the coupling interaction of 3 d orbits between V and Fe atoms. Higher Fe concentration is beneficial to improve the coercivity, which is attributed to the formation of the second phase Fe3 Se4. This simple chemical preparation method can be extended to prepare the other 2 D materials.

关键词： VSe2 Fe doping Two-dimensional nanosheets Room-temperature ferromagnetism Chemical method