检索结果-南通市图书馆

Comparisons of urban-related warming for Shenzhen and guangzhou

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2018年第4期11卷 330-337页

作者： zhaO deming zha Jinlin WU Jian CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences department of Atmospheric Science Yunnan University

Urban-related warming in two first-tier cities(guangzhou and Shenzhen)in southern China with similar large-scale climatic backgrounds was compared using the nested weather research and forecasting regional climate *** default urban data in the model were replaced by reconstructed annual urban data retrieved from satellite-based images for both coarse-(including all of China)and fine-resolution domains(eastern China and three city clusters in China:Beijing– Tianjin–Hebei(BTH),the Yangtze River delta(YRd),and the Pearl River delta(PRd)),which reproduced urban surface expansion during the past few *** results showed that the 37-year(1980–2016)area-averaged annual urban-related warming was similar(0.69°C/0.64°C)between the urban areas of guangzhou/Shenzhen;however,the values across the entire area of the two cities varied(0.21°C/0.45°C).Seasonal characteristics could be detected for mean surface air temperatures(SAT)at 2 m,SAT maximum and minimum,and diurnal temperature range(dTR).Both the SAT maximum and minimum generally increased,especially over urban areas;however,changes in the SAT minimum were larger,which induced a decrease in *** dTR in summer decreased by-0.25°C/-0.86°C across the entire area of the two cities and decreased by-0.93°C/-1.15°C over urban *** contributions of urban surface expansion to regional warming across the entire area of the two cities were approximately 17%/35%of the overall warming and much greater over ***,the values over urban areas were much closer to the values from total warming(35%/44%).

关键词： Urban surface expansion guangzhou Shenzhen urban-related warming numerical simulation

direct energy rebound effect for road transportation in China

在线全文

学校读者我要写书评

暂无评论

Frontiers of Engineering Management 2023年第4期10卷 597-611页

作者： donglan zha Pansong JIANg Xue zha.g College of Economics and Management Nanjing University of Aeronautics and AstronauticsNanjing 211106China Research Centre for Soft Energy Science Nanjing University of Aeronautics and AstronauticsNanjing 211106China

The enhancement of energy efficiency stands as the principal avenue for attaining energy conservation and emissions reduction objectives within the realm of road ***,it is imperative to acknowledge that these objectives may,in part or in entirety,be offset by the phenomenon known as the energy rebound effect(ERE).To quantify the long-term EREs and short-term EREs specific to China’s road transportation,this study employed panel cointegration and panel error correction models,accounting for asymmetric price *** findings reveal the following:The long-term EREs observed in road passenger transportation and road freight transportation range from 13%to 25%and 14%to 48%,respectively;in contrast,the short-term EREs in road passenger transportation and road freight transportation span from 36%to 41%and 3.9%to 32%,*** is noteworthy that the EREs associated with road passenger transportation and road freight transportation represent a partial rebound effect,falling short of reaching the magnitude of a counterproductive backfire *** leads to the inference that the upsurge in energy consumption within the road transportation sector cannot be solely attributed to advancements in energy ***,various factors,including income levels,the scale of commodity trade,and industrial structure,exert more substantial facilitating ***,the escalation of fuel prices fails to dampen the demand for energy services,whether in the domain of road passenger transportation or road freight *** light of these conclusions,recommendations are proffered for the formulation of energy efficiency policies pertinent to road transportation.

关键词： road transportation direct energy rebound effect asymmetric price effects panel data model

The“Beijing Consensus”and the Chinese Model of University Autonomy

在线全文

学校读者我要写书评

暂无评论

Frontiers of Education in China 2014年第1期9卷 42-62页

作者： Qiang zha Ruth HAYHOE Faculty of Education York UniversityTorontoM3J 1P3Canada Ontario Institute for Studies in Education University of TorontoTorontoM5S 1V6Canada

This paper attempts to address connections between the Chinese model for development or the“Beijing Consensus”and Chinese *** universities seem to be caught between serving governmental agendas and pursuing their own goals as an academic *** until recently,they had become used to following the lead of the government,which often comes with rationales and approaches featuring pragmatism and *** on the perspectives of social embeddedness and external control of organizations in higher education,we argue that the lack of dynamism and innovation that is hindering Chinese higher education’s development is largely owing to the political,social,and cultural factors prevailing in the environment in which the universities *** in another way,Chinese universities are confronting a crisis,owing to the inbuilt constraints of China’s development model.

关键词： Beijing Consensus Chinese university crisis autonomy

Stability Analysis of PLL Influenced by Control Loops in grid-connected Converters Under Fault disturbance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2020年第2期6卷 239-248页

作者： Yushuang Liu Meng Huang Xiaoming zha Herbert Ho-Ching Iu School of Electrical Engineering and Automation Wuhan UniversityWuhan 430000China School of Electrical Electronic and Computer EngineeringThe University of Western AustraliaCrawley WA 6009Australia

When the power grid suffers from grid faults that cause phase disturbances,the grid-connected converter becomes destabilized by the interaction between the phase-locked loop(PLL)and the control *** this paper,the stability of the PLL affected by the control loop under transient grid faults is ***,the equivalent model of the PLL under the influence of the control loop is ***,different response processes of PLLs under the ground fault with various control parameters are qualitatively ***,a small-signal model is proposed to assess the stability of the PLL under different control loop *** system poles can be calculated to show the physical origin of the ***,simulations of a three-phase 21-level modular multilevel converter(MMC)built in PSCAd and a down-scale experiment is performed to verify the parameter influence of the control loop on the PLL.

关键词： Control loop grid-connected MMC ground fault phase-locked loop transient stability

The Transformation of China’s Key Science and Technology Universities in the Move to Mass Higher Education

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Education in China 2010年第4期5卷 531-557页

作者： ZHOU guangli Qiang zha School of Educational Research Huazhong University of Science and TechnologyWuhan 430074China Faculty of Education York UniversityOntario M3J1P3Canada

China’s key science and technology universities are modelled on the FrenchÉcole *** such,they are utilitarian institutions,rooted in the concept of cultivating manpower for society’s economic progress,and tending to ignore the development of the *** China’s elite higher education system took in a rapidly increasing number of students in the recent massification process,China’s key science and technology universities underwent reform to become more comprehensive in curricular offerings and more research-oriented in *** authors have uncovered an interesting phenomenon:despite repeated discussion in academic circles,this transformation was never actually a conscious strategic choice for *** when the Chinese government launched a program of higher education“massification”did universities develop their own unique reform strategies in a move to become more comprehensive and more research *** authors have adopted a multi-stream analysis framework to describe and analyze three case study universities:University of Science and Technology of China(USTC),Huazhong University of Science and Technology(HUST),and Northwest Agriculture and Forestry University(NWAFU).It was found that Chinese universities already have quite a high level of autonomy,but that the government still has the power to make strategic *** university’s decision-making mechanism has been an independent process within the constraints of the political economic structure over this period,and policy-making has combined top-down and bottom-up processes.

关键词： massification of higher education key science and technology universities Chinese university university transformation

Construction of Chiral All-Carbon Quaternary Stereocenters by Asymmetric Friedel-Crafts Reaction of Isatin derivatives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2022年第2期40卷 195-200页

作者： Jindong Li Wenjing Lu Yangmian Lu Zhenggen zha Zhiyong Wang Hefei National Laboratory for Physical Sciences at Microscale Center for Excellence in Molecular Synthesis of Chinese Academy of SciencesSchool of Chemistry and Materials Science in University of Science and Technology of ChinaHefeiAnhui 230026China

Un der the catalysis of chiral Cu(ll)complex,C2 and C3 alkylati on of pyrrole and C3 alkylation of in dole were realized simulta *** chiral oxindole skeleton with an all-carb on quater nary stereogenic cen ter at the C3-position could be obtai ned exclusively with high yields(up to 95%)and excellent enantioselectivities(up to>99%).

关键词： Asymmetric synthesis Chemoselectivity Enan tioselectivity Nucleophilic addition Oxindole

Study on the epoxidation of olefins with H_(2)O_(2)catalyzed by biquaternary ammonium phosphotungstic acid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第6期58卷 146-154页

作者： Zijie zha.g Qianyu zha Ying Liu Zhibing zha.g Jia Liu Zheng Zhou School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China

Selective epoxidation of olefins is an important field in chemical *** this work,we developed a new phosphotungstic acid catalyst{[(C_8H_(17))(CH_(3))_(2)N]_(2)(CH_(2))_(3)}_(1.5){PO_(4)[WO(O_(2))_(2)]_(4)}with long carbon chain and biquaternary ammonium *** could be epoxidized to cyclohexene oxide in 96.3%conversion and 98.2%*** catalyst type,solvent type,catalyst loading,initial molar ratio,temperature,cycle performance and substrate extensibility were studied and optimized,the kinetic parameters about overall reaction and unit reaction were also *** light scattering analysis was carried out to explain the different catalytic performance between catalysts with different carbon chain *** novel catalyst and the corresponding dynamics and mechanism study could probably help the industrial application on the epoxidation of cyclohexene with H_(2)O_(2).

关键词： Epoxidation of olefins Phosphotungstic acid Cyclohexene Kinetic study

Preparation and thermal-mechanical property evaluation of cellulose insulation paper with differing nano-SiC contents

在线全文

学校读者我要写书评

暂无评论

High Voltage 2023年第3期8卷 599-610页

作者： Yiyi zha.g Chuqi Xu Wenchang Wei Yuke deng Shuangxi Nie Junwei zha Key Laboratory of disaster Prevention and Structural Safety of Ministry of Education Guangxi UniversityNanningChina guangxi Key Laboratory of disaster Prevention and Engineering Safety Guangxi UniversityNanningChina School of Light Industry and Food Engineering Guangxi UniversityNanningChina School of Chemistry and Biological Engineering University of Science&Technology BeijingBeijingChina

Cellulose insulation paper is the main component of oil-paper insulation systems in oilimmersed ***,the poor thermal conductivity and thermal stability of the cellulose can lead to thermal *** is critical to address this issue by improving the performance of cellulose,nano-SiC-modified cellulose models were established by molecular simulation,while nano-SiC composite papersheets were prepared based on the simulation results,and the effects of different contents of nano-SiC on the papersheets were ***,doping nano-SiC particles can enhance the thermal stability of cellulose;compared with the unmodified papersheet,the thermal conductivity and tensile strength of the modified papersheets are increased by 44.3%and 42.8%,*** degree of polymerisation of the modified papersheet decreased more slowly than that of the unmodified papersheet under accelerated thermal ageing,showing that the modified papersheet has better anti-ageing ***,with the addition of nano-SiC,the simulations showed that the mean square displacement of the cellulose decreases dramatically and the distribution of the free volume becomes difficult to disperse,which corresponds to the decrease in porosity in the *** a result,this research provides a way for improving the thermal-mechanical properties of cellulose that has practical application significance.

关键词： insulation thermal property

Intelligent Fast Cell Association Scheme Based on deep Q-Learning in Ultra-dense Cellular Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2021年第2期18卷 259-270页

作者： Jinhua Pan Lusheng Wang Hai Lin Zhiheng zha Caihong Kai Key Laboratory of Knowledge Engineering with Big data Ministry of Education.School of Computer Science and Information EngineeringHefei University of TechnologyHefei 230601China Anhui Province Key Laboratory of Industry Safety and Emergency Technology Hefei 230601China Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education.School of Cyber Science and EngineeringWuhan UniversityWuhan 430072China

To support dramatically increased traffic loads,communication networks become *** cell association(CA)schemes are timeconsuming,forcing researchers to seek fast *** paper proposes a deep Q-learning based scheme,whose main idea is to train a deep neural network(dNN)to calculate the Q values of all the state-action pairs and the cell holding the maximum Q value is *** the training stage,the intelligent agent continuously generates samples through the trial-anderror method to train the dNN until *** the application stage,state vectors of all the users are inputted to the trained dNN to quickly obtain a satisfied CA result of a scenario with the same BS locations and user *** demonstrate that the proposed scheme provides satisfied CA results in a computational time several orders of magnitudes shorter than traditional ***,performance metrics,such as capacity and fairness,can be guaranteed.

关键词： ultra-dense cellular networks(UdCN) cell association(CA) deep Q-learning proportional fairness Q-learning