检索结果-南通市图书馆

Journal of Thermal Science 2023年第1期32卷 125-134页

作者： WANG Zefeng HAN Wei li yimin Beijing Huairou Laboratory Beijing 101400China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academyof Sciences Beijing 100049China

A proper operating strategy is helpful to improve the off-design performance of combined cooling,heating and power(CCHP)systems,providing high efficiency and low *** energy level difference graphic analysis method is used to identify energy level as well as exergy destruction of the part-load *** method illustrates the energy efficiency upgrading mechanism of the flue gas reinjecting(FGR)operating *** is referenced to a reducing turbine inlet temperature(TIT)operating *** comparison,the FGR operating strategy leads to a 2.62%exergy distribution reduction in a gas turbine at an 85%load level due to the decrease of the energy level *** the output power is reduced further,the FGR operating strategy is supplanted by the TIT operating strategy with the limit of compressor inlet ***,the opposite results of exergy distribution are presented in the exhaust-heat recovery devices.A heat-driven refrigeration and power cycle is introduced in a typical CCHP system as a ***,the results suggest that the operational flexibility of the CCHP system is improved by enlarging the ratio of cooling to electricity.

关键词： CCHP systems off-design performance energy level difference analysis operating strategies

Spatial-temporal variation features and law of gas concentration in the fully mechanized working face under the condition of intermittent ventilation

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第6期29卷 963-969页

作者： Yinpin Cao yimin li Zhongning Zhou School of Electrical and Power Engineering China University of Mining & Technology

Based on the fluid mechanics and mass transfer theory,a mathematical model of the spatial-temporal variation of gas was derived to avoid the gas accident caused by the main fan stopping ventilation under the condition of intermittent ventilation in the *** to the actual parameters of the tunnel,a numerical calculation model was *** spatial-temporal variation of gas concentration in the fully mechanized working face under the condition of intermittent ventilation was calculated by using the commercial package Fluent,and the correctness of the calculated results was verified by the actual monitoring data of the ***,the gas concentration was calculated under different wind velocities at driving face in coal tunnel,and the result showed that the gas can be carried effectively by the wind when the wind velocity is about 1.8 m/***,the distributions of wind velocity and gas concentration at driving face were studied at 1.8 m/s,and the result showed the gas concentration increased gradually with the distance close to the outlet,but the gas concentration almost kept constant at the height of driving ***,the distribution of gas concentration was investigated with time after the ventilation was stopped and restarted,*** gas concentration of test point gradually increased with the increment of downtime,when the downtime was 40 min,the gas concentration of test point 3 reached the maximum *** gas concentration increased gradually and reached the maximum after10 min of restart,then sharply decreased and kept constant.

关键词： Fully mechanized working face Intermittent ventilation Gas concentration

IMPROVEMENT OF RHEOLOGICAL AND SHAPE RETENTION PROPERTIES OF WAX-BASED MIM BINDER BY MULTI-POLYMER COMPONENTS

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第1期9卷 24-31页

作者： li, yimin Huang, Baiyun Qu, Xuanhui Central South Univ of Technology Changsha China

ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｔａｌｉｎｊｅｃｔｉｏｎｍｏｌｄｉｎｇ（ＭＩＭ）ｉｓａｎｅｍｅｒｇｉｎｇｎｅｔｓｈａｐｉｎｇｐｒｏｃｅｓｗｉｔｈｔｈｅｃａｐａｂｉｌｉｔｙｏｆｐｒｏｄｕｃｉｎｇｃｏｍｐｌｅｘｍｅｔａｌ... 详细信息

ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｔａｌｉｎｊｅｃｔｉｏｎｍｏｌｄｉｎｇ（ＭＩＭ）ｉｓａｎｅｍｅｒｇｉｎｇｎｅｔｓｈａｐｉｎｇｐｒｏｃｅｓｗｉｔｈｔｈｅｃａｐａｂｉｌｉｔｙｏｆｐｒｏｄｕｃｉｎｇｃｏｍｐｌｅｘｍｅｔａｌｐｒｏｄｕｃｔｓｗｈｉｃｈｃａｎ?..

关键词： rheological property metal injection molding (MIM) binder polymer component

Relocation Selection for Poverty Alleviation:Factor Analysis and GIS Modeling

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第3期8卷 466-475页

作者： li yimin YIN Haihong liU Suhong Yunnan Institute of Geography College of Environment and Resource Yunnan University Kunming 650091 China College of Geography and Remote Sensing Sciences Beijing Normal University Beijing 100875 China

Resettlement is considered a major policy measure in two major Chinese policy programs,the "Great Development of the West" and poverty alleviation in the new century,and the "New Countryside Development".The selection of the target location of resettlement sites for poverty-stricken villages is of critical importance to the success of resettlement projects,yet the selection process is challenged by the need for analyzing a variety of contributing factors,and the need for many rounds of tedious data *** in this paper we present an in-depth analysis of the major factors and data processing model concerning mountainous povertystricken villages,which also takes a major part of China's poor *** analysis shows the following factors bear the most importance in resettlement selection:1) topography:candidate areas should have slope less than 25 degrees and altitude less than 2400 meters.2) accessibility:close to market conventions places and transportation facilities.3) farming resources:with abundant land and water resources.4) non-intrusiveness:interests of receiving villages should be considered and negative impact minimized.A simple measure could be having the candidate area 1000 m away from the receiving residents.5) Minimal ecological and political footprint:candidate areas shall not conflict with nature conservation areas or nationally planned key land use projects.6) Social and cultural compatibility:residents will better off if relocated in the same county,considering language,religion,ethnic culture and other *** Makuadi,Lushui County of Nujiang Prefecture as a case study,we demonstrate how GIS analysis and modeling tools can be used in the selection process of resettlement projects in mountainous areas.

关键词： Resettlement Makuadi village Geographic modeling GIS Analysis China

Preparation of three-dimensionally ordered macroporous perovskite materials

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第20期56卷 2156-2161页

作者： FANG JunFei XUAN yimin li Qiang School of Power Engineering Nanjing University of Science & TechnologyNanjing 210094China

In this paper,we use La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 as examples to demonstrate a preparation method for threedimensionally ordered macroporous(3DOM) perovskite thermochromic *** spheres with an average diameter of 220 nm were self-assembled into a three-dimensionally ordered colloidal crystal template.A mixed metal nitrate solution prepared using La(NO3) 3·6H2O,Ca(NO3) 2·4H2O,Sr(NO3) 2,Mn(CH3COO) 2·4H2O and an ethanol precursor was used to fill the interstitial voids of the polystyrene colloidal crystal templates.3DOM La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 materials were then obtained after the sphere templates were removed via drying and *** results show that the framework of the 3DOM materials can have different thicknesses and pore shrinkage rates by varying the filling *** addition,the Curie temperatures of the 3DOM and bulk La0.8Sr0.2MnO3 materials can be varied by altering the preparation method.

关键词：三维有序大孔变色材料制备方法钙钛矿 La(NO3)3 聚苯乙烯球 3DOM 胶体晶体

Investigation on the mechanism of convective heat and mass transfer with double diffusive effect inside a complex porous medium using lattice Boltzmann method

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2010年第26期55卷 3051-3059页

作者： ZHAO Kai XUAN yimin li Qiang School of Power Engineering Nanjing University of Science & Technology Nanjing 210094 China

A new lattice Boltzmann model is proposed for the coupling of multi-physics in natural convection by introducing another distri-bution function to represent the scalar transport of mass and an additional source term on the right hand side of the lattice Boltz- mann equation (LBE) based on the TD2G9 model. According to the Boussinesq assumption and considering the coupled diffusive effect, the governing equations for the coupling of multi-physics in natural convection is proposed based on the non-equilibrium thermodynamic theory. Combined with the algorithm for the reconstruction of a porous medium, this model is used to investigate the coupled heat and mass transfer under multi-physics of natural convection inside a porous medium at the pore scale. The characteristic of profiles of dimensionless velocity, temperature and concentration are shown graphically for different values of Rayleigh number (Ra) and porosity. Furthermore, the influence of the temperature gradient on the mass transfer inside a porous medium has been examined numerically. Thus, the mechanism of the coupled heat and mass transfer inside a porous medium is investigated numerically at the pore scale innovatively.

关键词：多孔介质自然对流格子玻尔兹曼方法扩散效应传输机制格子Boltzmann模型非平衡热力学理论热质

Simultaneous optical and electrochemical recording of single nanoparticle electrochemistry

在线全文

学校读者我要写书评

暂无评论

Nano Research 2017年第5期10卷 1740-1748页

作者： linlin Sun yimin Fang Zhimin li Wei Wang Hongyuan Chen State Key Laboratory of Analytical Chemistry for life Science School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093 China

Single nanoparticle collisions have become popular for studying the electro- chemical activity of single nanoparticles by determining the transient current during stochastic collisions with the electrode surface. However, if only the electrochemical current is measured, it remains challenging to identify and characterize the individual particle that is responsible for a specific current peak in a collision event; this hampers the understanding of the structure-activity relationship. Herein, we report simultaneous optical and electrochemical recording of a single nanoparticle collision; the electrochemical signal corresponds with the activity of a single nanoparticle, and the optical signal reveals the size and location of the same nanoparticle. Consequently, the structure （optical signal）- activity （electrochemical signal） relationship can be elucidated at the single nanoparticle level; this has implications for various applications including batteries, electrocatalysts, and electrochemical sensors. In addition, our previous studies have suggested an optical-to-electrochemical conversion model to independently calculate the electron transfer rate of single nanopartides from the optical signal. The simultaneous optical and electrochemical recording achieved in the present work enables direct and quantitative validation of the optical-to-electrochemical conversion model.

关键词： single nanoparticlecollision surface plasmonresonance microscopy plasmonics-basedelectrochemicalmicroscopy Ag nanoparticles

Solvent de binding of water soluble binder in powder injection moulding

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1999年第3期9卷 578-581页

作者： li Songlin(李松林) Huang Baiyun(黄伯云) Qu Xuanhui(曲选辉) li yimin(李益民) Cent S Univ Technol State Key Lab Powder Met Changsha 410083 Peoples R China

The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent debinding rate. After studying the debinding of a green part with a thickness of 4.26 mm, it was found that, the debinding rate of polyethylene glycol(PEG) in water and alcohol was high initially, and then decreased; however, it would increase with temperature increasing. At room temperature, the dissolution rate of PEG in water was higher than that in alcohol, but the latter would be much faster with temperature increasing because the debinding activation energy in alcohol was 51.44 kJ·mol -1 ·K -1 , much higher than 24.23 kJ·mol -1 ·K -1 in water. With a green part thickness larger than 4.26 mm, the debinding was controlled by diffusion; but with that smaller than 2.36 mm, the debinding was controlled by both dissolution and diffusion.

关键词： powder injection moulding water soluble binders solvent debinding

Intelligent service function chain mapping framework for cloud-and-edge-collaborative IoT

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2022年第3期29卷 54-68,104页

作者： Yang Chao li yimin li Tong Xu Siya Qi Jun Zhang Yu Information and Communication Branch State Grid Liaoning Electric Power Co.Ltd.Shenyang 110004China State Key Laboratory of Networking and Switching Technology Beijing University of Postsand TelecommunicationsBeijing 100876China State Grid liaoning Electric Power Research Institute Shenyang 110004China

With the rapid development of Internet of thing(IoT) technology, it has become a challenge to deal with the increasing number and diverse requirements of IoT services. By combining burgeoning network function virtualization(NFV) technology with cloud computing and mobile edge computing(MEC), an NFV-enabled cloud-and-edge-collaborative IoT(CECIoT) architecture can efficiently provide flexible service for IoT traffic in the form of a service function chain(SFC) by jointly utilizing edge and cloud resources. In this promising architecture, a difficult issue is how to balance the consumption of resource and energy in SFC mapping. To overcome this challenge, an intelligent energy-and-resource-balanced SFC mapping scheme is designed in this paper. It takes the comprehensive deployment consumption as the optimization goal, and applies a deep Q-learning(DQL)-based SFC mapping(DQLBM) algorithm as well as an energy-based topology adjustment(EBTA) strategy to make efficient use of the limited network resources, while satisfying the delay requirement of users. Simulation results show that the proposed scheme can decrease service delay, as well as energy and resource consumption.

关键词： Internet of thing(IoT) mobile edge computing network function virtualization(NFV) deep Q-learning(DQL)

同方期刊数据库

Numerical simulation on mixing dynamics of flexible filamentous particles in the transverse section of a rotary drum

在线全文

学校读者我要写书评

暂无评论

Particuology 2013年第5期11卷 594-600页

作者： Fan Genga Yingchao Wang yimin li Longji Yuan Xinyong Wang Min liu Zhulin Yuan School of Electric Power Engineering China University of Mining and Technology School of Mechanics & Civil Engineering China University of Mining & Technology College of Energy Sources & Environment Engineering Southeast University

Flexible filamentous particles are a special kind of particles and play a significant role in many industrial processes. The mixing dynamics of flexible filamentous particles in the transverse section of a rotary drum were analyzed numerically in two dimensions. First, a chain model of slender bodies was introduced for particle dynamic studies, and each individual particle as well as each segment of the particle was tracked during the process. Then, the bulk movement of particles in the transverse section of a rotary drum was explored numerically and mixing dynamics of the particles were further investigated with visual representation. To quantify the quality of mixing, the mixing rates were investigated to determine the mixing extent of particles in the rotary drum. Furthermore, the effects of rotational velocity, flight height and filling degree on mixing dynamics were examined in detail. Moreover, the numerical results were compared with experimental data, and reasonable agreements were obtained, The numerical analyses provide valuable insights into the mixing dynamics of flexible filamentous particles.

关键词： Rotary drumMixing dynamicsFlexible filamentous particlesChain modelSimulation