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Stability Criteria of Nonlinear Impulsive Differential Equations with Infinite Delays

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Acta Mathematicae Applicatae Sinica 2015年第4期31卷 921-934页

作者： Yang LIU Bo WU Xiu-shan cai Department of Mathematics Southeast University College of Mathematics Physics and Information EngineeringZhejiang Normal UniversityJinhua 321004China Graduate School Zhejiang Normal University

In this paper, we consider the uniform stability and uniformly asymptotical stability of nonlinear impulsive infinite delay differential equations. Instead of putting all components of the state variable x in one Lyapunov function, several Lyapunov-Razumikhin functions of partial components of the state variable x are used so that the conditions ensuring that stability are simpler and less restrictive; moreover, examples are discussed to illustrate the advantage of the results obtained.

关键词： uniformly asymptotical stability impulsive differential equation infinite delay

Facile preparation of organometallic perovskite films and high-efficiency solar cells using solid-state chemistry

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Nano Research 2015年第1期8卷 263-270页

作者： Lei Chen Feng Tang Yixin wang shan Gao Weiguo Cao Jinhua cai Liwei Chen Department of Chemistry Shanghai University Shanghai 200444 China i-Lab Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou Jiangsu 215123 China Nano Science and Technology Institute University of Science and Technology of China Suzhou Jiangsu 215123 China

The power conversion efficiency of organometallic perovskite-based solar cells has skyrocketed in recent years. Intensive efforts have been made to prepare high-quality perovskite films tailored to various device configurations. Planar heterojunction devices have achieved record efficiencies; however, the preparation of perovskite films for planar junction devices requires the use of expensive vacuum facilities and/or the fine control of experimental conditions. Here, we demonstrate a facile preparation of perovskite films using solid-state chemistry. Solid-state precursor thin films of CHBNH3I and PbI2 are brought into contact with each other and allowed to react via thermally accelerated diffusion. The resulting perovskite film displays good optical absorption and a smooth morphology. Solar cells based on these films show an average efficiency of 8.7% and a maximum efficiency of 10%. The solid-state synthesis of organometallic perovskite can also be carried out on flexible plastic substrates. Using this method on a PET/ITO substrate produces devices with an efficiency of 3.2%. Unlike existing synthetic methods for organometallic perovskite films, the solid-state reaction method does not require the use of orthogonal solvents or careful adjustment of reaction conditions, and thus shows good potential for mass production in the future.

关键词： solid-state chemistry perovskite solar cells planar heterojunction flexible substrates

A flexible model-free tram signal priority method with a large coordination scope in China

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Transportation Safety and Environment 2024年第3期6卷 28-34页

作者： shan wang shanghai Urban Construction Design and Research Institute No.3447 Dongfang RoadPudong DistrictShanghai 200125China

Tram systems with the advantages of reliable operation,comfort,low emissions and moderate capacity have been quite popular in recent years in ***,there are still problems with tram signal control(*** model,signal control strategies).In-depth analysis on existing operational issues of trams,calculation of two evaluation indexes,as well as a flexible model-free tram signal priority method were developed to deal with tram *** research in Songjiang District,shanghai shows that:(1)The function of the green extension strategy is limited with c.a.10%tram priority improvement,while the optimal one can reach to 85%higher on average.(2)A scheme with a benefit for trams and with no negative impact,and even benefits,for general traffic can be realized.(3)The optimal solution is beneficial for intersections with a maximum c.a.70%amelioration with delay decreasing from 132.7 s/vehicle to 40.89 s/vehicle,or from 104.77 s/capita to 22.31 s/*** paper has great significance for the signal optimization and safety of tram systems,even the development of a comprehensive transportation system for a city.

关键词： tram signal priority large coordination scope model-free signal control average passenger delay average vehicle delay

Chlorobenzenes in waterweeds from the Xijiang River (Guangdong section) of the Pearl River

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Journal of Environmental Sciences 2007年第10期19卷 1171-1177页

作者： DU Qing-ping JIA Xiao-shan HUANG cai-na Faculty of Environmental Science and Engineering Guangdong University of Technology Guangzhou 510006 China School of Environmental Science and Engineering Sun Yat-sen University Guangzhou 510275 China

The Xijiang River is the major source of water for about 4.5 millions of urban population and 28.7 millions of rural population. The water quality is very important for the health of the rural population. The concentration and distribution of chlorobenzenes （CBs） in both water and waterweeds collected from 4 stations in the Xijiang River （Gangdong section） of the Pearl River in April and November were determined. The result showed that nearly every congener of CBs was detected. The total contents of CBs （ZCBs） in the river water ranged from 111.1 to 360.0 ng/L in April and from 151.9 to 481.7 ng/L in November, respectively. The pollution level of CBs in the water in April was higher than that in November. The contents of ZCBs in waterweeds ranged from 13.53×10^2μg/g to 38.27×10^2μg/g dry weight （dw）. There was no significant difference between April and November in waterweeds. The distribution of CBs in roots, caulis, and leaves of Vallisneria spiralis L. showed different patterns. The leaves mainly contained low-molecular-weight CBs （DCBs）, whereas the roots accumulated more PCBs and HCBs. The average lgBCFlip （bioconcentration factor） of CBs ranged from 0.64 to 3.57 in the waterweeds. The spatial distribution character of CBs in the Xijiang River was： Fengkai County 〈 Yunan County 〈 Yun＇an County 〈 Gaoyao County according to the ZCBs, and the pollution deteriorated from the upstream to the downstream of the Xijiang River. Further analysis demonstrated that the discharge of waste containing CBs may be the main source of CBs pollution in the Xijiang River .

关键词： chlorobenzenes pollution water water weeds distribution bioconcentration factor

Uniform Regularity for the Isentropic Compressible Magnetohydrodynamic System

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 410-416页

作者： Ji-shan FAN Fu-cai LI GEN NAKAMURA Department of Applied Mathematics Nanjing Forestry UniversityNanjing 210037China Department of Mathematics Nanjing UniversityNanjing 210093China Department of Mathematics Hokkaido UniversitySapporo 060-0810Japan

In this paper we first establish the uniform regularity of smooth solutions with respect to the viscosity coefficients to the isentropic compressible magnetohydrodynamic system in a periodic domain T;.We then apply ou... 详细信息

关键词： isentropic compressible magnetohydrodynamic system uniform regularity

Heat transfer analysis of feedthrough flange under high alternating current condition

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Science China(Technological Sciences) 2020年第4期63卷 686-692页

作者： cai Xiao wang HaiPeng School of Physical Science and Technology Northwestern Poly technical UniversityXi'an 710072China

The heat transfer characteristics of feedthrough flange under high alternating current excitation were investigated by threedimensional finite element *** correlations between the heat transfer behaviors and system parameters including applied current,ceramic thickness and working time were discussed comprehensively.A remarkable absorbed power beyond 100 W in flange would be produced by the electromagnetic field from *** natural cooling condition,there is an obvious temperature rise about 40℃in the flange center after 10 min of current *** types of water cooling solutions acting on flange surface,*** type,circle type and S type solutions,were proposed to reduce the flange temperature under high alternating current and long working time *** the S type water cooling mode,the best cooling effect can be achieved that the maximum temperature rise is about 20℃and the average temperature rise is less than 5℃.

关键词： heat transfer cooling solution feedthrough flange induction heating

Effects of Elevated CO_2 on Growth, Carbon Assimilation, Photosynthate Accumulation and Related Enzymes in Rice Leaves during Sink-Source Transition

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Journal of Integrative Plant Biology 2008年第6期50卷 723-732页

作者： Jun-Ying Li Xing-Hua Liu Qing-Sheng cai Hui Gu shan-shan Zhang Yan-Yan Wu Chun-Jiao wang College of Life Sciences Nanjing Agricultural University N anjing 210095 China Yunnan Tobacco Research Institute Yuxi 653100 China

To study the effects of growing rice （Oryza sativa L.） leaves under the treatment of the short-term elevated CO2 during the period of sink-source transition, several physiological processes such as dynamic changes in photosynthesis, photosynthate accumulation, enzyme activities （sucrose phosphate synthase （SPS）, and sucrose synthase （SS））, and their specific gene （spsl and RSusl） expressions in both mature and developing leaf were measured. Rice seedlings with fully expanded sixth leaf （marked as the source leaf, L6） were kept in elevated （700 μmol/mol） and ambient （350 mol/L） CO2 until the 7th leaf （marked as the sink leaf, L7） fully expanded. The results demonstrated that elevated CO2 significantly increased the rate of leaf elongation and biomass accumulation of L7 during the treatment without affecting the growth of L6. However, in both developing and mature leaves, net photosynthetic assimilation rate （A）, all kinds of photosynthate contents such as starch, sucrose and hexose, activities of SPS and SS and transcript levels of spsl and RSusl were significantly increased under elevated CO2 condition. Results suggested that the elevated CO2 had facilitated photosynthate assimilation, and increased photosynthate supplies from the source leaf to the sink leaf, which accelerated the growth and sink-source transition in new developing sink leaves. The mechanisms of SPS regulation by the elevated CO2 was also discussed.

关键词： elevated CO2 photosynthate photosynthesis rice sink-source transition sucrose metabolism

Teaching mechanism empowered by virtual simulation: Edge computing–driven approach

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Digital Communications and Networks 2023年第2期9卷 483-491页

作者： Ziqiao wang Xiaomu cai Yanbian University Yanji133000China

With the rapid development of network and communication techniques,the teaching forms have become *** enhance the education experience and improve the teaching environment,an increasing number of educational institutions have adopted virtual simulation technology.A typical teaching mechanism is to exploit Virtual Reality(VR)technology,which affords participants an immersive ***,such a VRbased mode is highly ***,the performance of this technology requires further *** one hand,for VR 360video,the current intraframe decision cannot adapt to rapid response *** the other hand,the generated data size is considerably large and fast computation may not be realized,depending on the local VR ***,this study proposes an improved teaching mechanism empowered by edge computing–driven VR,called VE4T,that involves two ***,an intraframe decision algorithm for VR 360videos is devised to realize the rapid ***,an edge computing framework is proposed to offload some tasks to an edge server for computation,where a task scheduling strategy is developed to check whether a task needs to be ***,experiments are performed using a practical teaching scenario with some VR *** obtained results demonstrate that VE4T is more efficient than existing mechanisms.

关键词： Virtual reality Edge computing Immersive experience Scheduling strategy Intraframe decision

Effect of Ni addition on microstructure and mechanical properties of Al–Mg–Si–Cu–Zn alloys with a high Mg/Si ratio

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 740-751页

作者： Gao-jie Li Ming-xing Guo Yu wang cai-hui Zheng Ji-shan Zhang Lin-zhong Zhuang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

The effect of adding 0.03wt%Ni on the microstructure and mechanical properties of Al–Mg–Si–Cu–Zn alloys was systematically *** results reveal that the number density of spherical Fe-rich phases within grains increases with the addition of Ni,accompanied by the formation of Q(Al3Mg9Si7Cu2)precipitates around the spherical Fe-rich ***,Ni addition is beneficial to reducing the grain size in the as-cast *** the homogenization process,Q phases could be completely dissolved and the grain size could remain basically ***,compared with the Ni-free alloy,the Fe-rich phase in the Ni-containing alloy is more likely to undergo the phase transformation and further form more spherical particles during homogenization *** thermomechanical processing,the distribution of Fe-rich phases in the Ni-containing alloy was further greatly improved and directly resulted in a greater formability than that of the Ni-free ***,a reasonable Ni addition positively affected the microstructure and formability of the alloys.

关键词： Al-Mg-Si-Cu-Zn alloy Ni addition Fe-rich phase phase transformation formability