检索结果-南通市图书馆

Flexibility of a 300 MW Arch Firing Boiler Burning Low Quality Coals

在线全文

学校读者我要写书评

暂无评论

Journal of China University of Mining and Technology 2007年第4期17卷 566-571页

作者： fang Qing-yan ZHOU Huai-chun WANG Hua-jian YAO Bin ZENG Han-cai State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan Hubei 430074 China

Experimental investigations on the flexibility of a 300 MW Arch Firing (AF) coal-fired boiler when burning low quality coals is reported. Measurements of gas temperature and species concentration and char sampling using a water-cooled suction pyrometer were carried out along the furnace elevation. The carbon content and the size distribu-tions of the char samples were obtained. The char morphology was examined using a field emission scanning electron microscope (FESEM). The char sampling was performed on this type of boiler for the first time. The results indicate that the flexibility of this boiler burning low quality coals under a moderate boiler load is better than its flexibility under a high boiler load. Because of the insufficient capacity of the coal pulverizers used,in case of low coal quality the pul-verized coal fineness will drastically decrease under high boiler loads. This causes an increase in the loss due to incom-plete mechanical and chemical combustion. This is the main cause of a low burnout degree of the pulverized coal and the decrease of the flexibility of this AF boiler under a high boiler load.

关键词： coal-fired boilers flexibility burnout temperatures size distributions

Gaskinetic Solutions for High Knudsen Number Planar Jet Impingement Flows

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2013年第9期14卷 960-978页

作者： chunpei cai chun Zou Department of Mechanical and Aerospace Engineering New Mexico State UniversityLas CrucesNew Mexico88003USA

This paper presents a gaskinetic study and analytical results on high speed rarefied gas flows from a planar *** beginning of this paper reviews the results for planar free jet expanding into a vacuum,followed by an investigation of jet impingement on normally set plates with either a diffuse or a specular *** results include exact solutions for flowfield and surface *** simulations with the direct simulation Monte Carlomethod were performed to validate these analytical results,and good agreement with this is obtained for flows at high Knudsen *** highly rarefied jet and jet impingement results can provide references for real jet and jet impingement flows.

关键词： Gaskinetic theory jet jet impingement Monte Carlo method

lahysiological links of circadian clock and biological clock of aging

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

Protein & Cell 2017年第7期8卷 477-488页

作者： fang Liu Hung-chun Chang Institute of Neuroscience State Key Laboratory of Neuroscience Key Laboratory of Primate Neurobiology CAS Center for Excellence in Brain Science and Intelligence Technology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China University of Chinese Academy of Sciences Shanghai 200031 China

Circadian rhythms orchestrate biochemical and physi-ological processes in living organisms to respond the day/night cycle. In mammals, nearly all cells hold self- sustained circadian clocks meanwhile couple the intrinsic rhythms to systemic changes in a hierarchical manner. The suprachiasmatic nucleus （SCN） of the hypothalamus functions as the master pacemaker to initiate daily synchronization according to the photope-riod, in turn determines the phase of peripheral cellular clocks through a variety of signaling relays, including endocrine rhythms and metabolic cycles. With aging, circadian desynchrony occurs at the expense of peripheral metabolic pathologies and central neurode- generative disorders with sleep symptoms, and genetic ablation of circadian genes in model organisms resem- bled the aging-related features. Notably, a number of studies have linked longevity nutrient sensing pathways in modulating circadian clocks. Therapeutic strategies that bridge the nutrient sensing pathways and circadian clock might be rational designs to defy aging.

关键词： circadian rhythms SCN longevity

Common Properties of the Operator Products in Local Spectral Theory

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第11期31卷 1715-1724页

作者： Kai YAN Xiao chun fang Department of Mathematics Tongji University

Let X,Y be Banach spaces, A,D ： X - Y and B,C ： Y - X be the bounded linear operators satisfying operator equation set ACD=DBD DBA=Acain this paper, we show that AC and BD share some basic operator properties such as the injectivity and the invertibility. Moreover, we show that AG＇ and BD share many common local spectral properties including SVEP, Bishop property （β） and Dunford property （C）.

关键词： Jacobson's lemma operator equation set common property local spectral theory

Spin-dependent transport induced by magnetization in zigzag graphene nanoribbons coupled to one-dimensional leads

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第1期21卷 458-461页

作者： Zhao Hua Zhang Xiao-Wei cai Tuo Sang Tian Liu Xiao-chun Liu fang Department of Physics and Electronics Qiannan Normal College for NationalitiesDuyun 558000China

We study spin transport in a zigzag graphene nanoribbon sample with two ferromagnetic strips deposited on the two sides of the ribbon. A tight-binding Hamiltonian was adopted to describe the sample connected to two one- dimensional leads. Our theoretical study shows that the resonance peaks of conductance for the spin-up and spin-down electrons are separated for the parallel configuration of the ferromagnetic strips, while they are not separated for the case of antiparallel configuration. This means that giant magnetoresistance can be produced at particular energies by altering the configurations of the ferromagnetic strips, and the device can be designed as a spin filter.

关键词： graphene nanoribbon giant magnetoresistance conductance current-voltage character-istic

Maneuver control at high angle of attack based on real-time optimization of integrated aero-propulsion

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第12期35卷 173-188页

作者： Juan fang Qiangang ZHENG Changpeng cai Haibo ZHANG College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To reduce the propulsion system installation thrust loss under high angle of attack maneuvering,a control method based on real-time optimization of the integrated aeropropulsion is ***,based on data fitting and physical principle,an integrated onboard model of propulsion system is established,which can calculate various performance parameters of the propulsion system in real time,and has high accuracy and real-time ***,to improve the compatibility of optimization real-time performance and search accuracy,the online optimization control of aero-propulsion system is realized based on an improved trust region ***,by controlling the auxiliary intake valve,a good match between inlet and engine is realized,which solves the problems of intake flow reducing and total pressure recovery coefficient declining,and improves the installation performance of propulsion *** simulation results indicate that,compared with the conventional independent engine control,the real-time integrated optimization method reduces the installed thrust loss by 3.61%under the design condition,and 4.58%under the off-design ***,the simulation on HIL(Hardware-In-theLoop)platform verifies the real-time performance of integrated optimization method.

关键词： High angle of attack Inlet/engine integration Real-time optimization Engine performance Auxiliary intake valve

Phase field simulation of dendrite growth in gas atomized binary Al-Ni droplets

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第3期18卷 43-52页

作者： Yuntao cai Pengjun fang Xinggang Li Yi Xu School of Materials Science&Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Materials Technology Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China

Catalytic powders with fine microstructures can be produced from a rapidly solidified gas atomized Al-Ni *** solidification microstructure of the droplets is closely linked with heat flow ***,the heat transfer conditions between the gas and droplet are essential to microstructural *** this study,a phase field model for simulating single and multiple dendrite growth in a binary Al-Ni alloy was constructed and the microstructural evolutions occurring during a gas atomization process were *** variations in the heat transfer coefficient and the boundary heat flux were taken into *** results revealed that the heat transfer coefficient of the atomized droplet in flight is correlated with the droplet size and the relative velocity between the droplet and the atomizing *** the simulation,the competition between boundary heat flux extraction and latent heat release from phase transition causes a recalescence process in thermal history,thereby affecting the gradient temperature distribution and,consequently,the dendrite *** growth under the effects of the heat transfer coefficient is restrained continuously because of the decreasing amount of *** computational results confirmed the fine homogeneous microstructure and low microsegregation levels of gas atomized powders.

关键词： Numerical simulation Dendrite morphology Solidification Gas atomization

The classification of bi-quintic parametric polynomial minimal surfaces

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

Applied Mathematics(A Journal of Chinese Universities) 2017年第1期32卷 14-26页

作者： LI cai-yun ZHU chun-gang School of Mathematics and Physics Science Dalian University of Technology Panjin 124221 China School of Mathematical Sciences Dalian University of Technology Dalian 116024 China

Parametric polynomial surface is a fundamental element in CAD systems. Since the most of the classic minimal surfaces are represented by non-parametric polynomial, it is interesting to study the minimal surfaces represented in parametric polynomial form. Recently,Ganchev presented the canonical principal parameters for minimal surfaces. The normal curvature of a minimal surface expressed in these parameters determines completely the surface up to a position in the space. Based on this result, in this paper, we study the bi-quintic isothermal minimal surfaces. According to the condition that any minimal isothermal surface is harmonic,we can acquire the relationship of some control points must satisfy. Follow up, we obtain two holomorphic functions f（z） and g（z） which give the Weierstrass representation of the minimal surface. Under the constrains that the minimal surface is bi-quintic, f（z） and g（z） can be divided into two cases. One case is that f（z） is a constant and g（z） is a quadratic polynomial, and another case is that the degree of f（z） and g（z） are 2 and 1 respectively. For these two cases,we transfer the isothermal parameter to canonical principal parameter, and then compute their normal curvatures and analyze the properties of the corresponding minimal surfaces. Moreover,we study some geometric properties of the bi-quintic harmonic surfaces based on the B′ezier representation. Finally, some numerical examples are demonstrated to verify our results.

关键词： polynomial parametric curvature canonical compute quadratic satisfy isothermal acquire verify

Development of a rapid measurement system for coarse aggregate morphological parameters

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第3期18卷 181-188页

作者： Hejun Zhu Huaiying fang Yuanyuan cai Ning Lv College of Mechanical Engineering and Automation Huaqiao UniversityXiamen 361021FujianChina

Morphological parameters of coarse aggregates,including the angularity index (Al),flat and elongated ratio,flatness ratio,and sphericity,strongly affect the performance of asphalt concrete.A device must be developed to efficiently and accurately measure these ***,a charge-coupled device camera and a linear profile scanner are combined to evaluate the *** Al is calculated using three *** results show that the fitted-ellipse method provides superior results among the three Al measurement ***,the use of a linear profile scanner improves the Al measurement ***,the proposed combination has high measurement efficiency and is suitable for batch inspections.

关键词： Charge-coupled device camera Linear profile scanner Angularity Flatness ratio Sphericity