检索结果-南通市图书馆

Chromatin-remodeling complexes:Conserved and plant-specific subunits in Arabidopsis

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2022年第2期64卷 499-515页

作者： Ji-Yun Shang xin-jian He National Institute of Biological Sciences Beijing102206 China Tsinghua Institute of Multidisciplinary Biomedical Research Tsinghua UniversityBeijing100084 China

Adenosine triphosphate-dependent chromatin remodeling complexes are important for the regulation of transcription,DNA replication,and genome stability in *** genetic studies have illustrated various biological functions of core and accessory subunits of chromatin-remodeling complexes in plants,the identification and characterization of chromatin-remodeling complexes in plants is lagging behind that in yeast and *** studies determined whether and how the Arabidopsis SWI/SNF,ISWI,INO80,SWR1,and CHD chromatin remodelers function in multi-subunit complexes in *** conserved and plant-specific subunits of chromatin-remodeling complexes have been identified and *** findings provide a basis for further studies of the molecular mechanisms by which the chromatinremodeling complexes function in plants.

关键词： ATPase chromatin remodeling complex INO80 ISWI SWI/SNF SWR1 transcription

Research of Temperature Tracer Method to Detect Tubular Leakage Passage in Earth-Dam

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 2006年第3期16卷 353-358页

作者： WANG xin-jian CHEN jian-sheng Geotechnical Institute Hohai University Nanjing Jiangsu 210098 China

The location, intensity and scope of concentrated leakage must be determined in order to repair earth-Dam scoured by the leakage. In this paper, firstly, heat tracer theory and distribution laws of temperature in soil body with leakage are discussed. Then temperature tracer model is established according to stable heat conduction theory. In such model, the concentrated seepage passage is simplified into a circular pipe as a boundary condition. The location, scope and flow-velocity of the concentrated leakage are estimated via ichnography of the lowest temperature based on temperature data from detecting wells by quantitative computation and qualitative analysis. In case study, the distribution characteristic of temperature (including temperature data of water in reservoir, drainage pipes and tail pond) can be interpreted by this model. A modified model is also set up, applied for detected data at different cross-sections of the leakage passage, in which the temperature data are rectified according to distances from data locations to calculating section. Finally, the model is solved by numerical iterative method, and the possible error of this theoretical model is discussed. The permeability coefficient in leakage area is identical with that of normal soil in magnitude after anti-seepage repairing accomplished, which indicates this model is effective.

关键词： seepage concentrated leakage passage heat conduction tracer method temperature field earth-dam

Exact Convergence Rate of the Local Limit Theorem for a Branching Random Walk in Z^(d)with a Random Environment in Time

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第5期45卷 805-822页

作者： jian-xin LIU Zhi-qiang GAO School of Mathematical Sciences Beijing Normal UniversityBeijing 100875China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875China

Consider a branching random walk with a random environment in time in the d-dimensional integer *** branching mechanism is governed by a supercritical branching process,and the particles perform a lazy random walk with an independent,non-identical increment *** A■Z^(d),let Z_(n)(A)be the number of offsprings of generation n located in *** exact convergence rate of the local limit theorem for the counting measure Z_(n)(·)is *** partially extends the previous results for a simple branching random walk derived by Gao(2017,*** Appl.).

关键词： Branching random walk Random environment Local limit theorems Exact convergence rate

Existence of Solutions for a Quasilinear Schr?dinger Equation with Potential Vanishing

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2023年第3期39卷 696-706页

作者： Yan-fang XUE jian-xin HAN xin-cai ZHU School of Mathematics and Statistics Xinyang Normal UniversityHenan 464000China

We study the following quasilinear Schrodinger equation-△u+V(x)u-△(u^(2))u=K(x)g(u),x∈R^(3),where the nonlinearity g(u)is asymptotically cubic at infinity,the potential V(x)may vanish at *** appropriate assumptions... 详细信息

关键词： quasilinear SchrOdinger equation vanishing potential asymptotically cubic mountain pass theorem

Effects of Fe content on the microstructure and properties of CuN i10FeM n1 alloy tubes fabricated by HCCM horizontal continuous casting

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第4期23卷 449-457页

作者： Yan-bin jiang Jun Xu xin-hua Liu jian-xin Xie Key Laboratory for Advanced Materials Processing of the Ministry of Education University of Science and Technology Beijing Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology Beijing

Heating-cooling combined mold（HCCM） horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content（1.08wt%–2.01wt%） on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.

关键词： copper nickel alloys iron content casting segregation mechanical properties corrosion resistance

Effect of trace HA on microstructure, mechanical properties and corrosion behavior of Mg-2Zn-0.5Sr alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第2期34卷 299-310页

作者： jian-xing Li Yuan Zhang Jing-Yuan Li jian-xin Xie School of Materials Science and Engineering University of Science and Technology Beijing Institute for Advanced Materials and Technology University of Science and Technology Beijing

Effect of the addition of trace HA particles into Mg-2Zn-0.5Sr on microstructure, mechanical properties, and bio-corrosion behavior was investigated in comparison with pure Mg. Microstructures of the Mg-2Zn-0.5Sr-xHA composites （x= 0, 0.1 and 0.3 wt%） were characterized by optical microscopy （OM）, scanning electron microscopy （SEM） equipped with energy dispersion spectroscopy （EDS） and X-ray diffraction （XRD）. Results of tensile tests at room temperature show that yield strength （YS） of Mg- 2Zn-0.5Sr/HA composites increases significantly, but the ultimate tensile strength （UTS） and elongation decrease with the addition of HA particles from 0 up to 0.3 wt%. Bio-corrosion behavior was investigated by immersion tests and electrochemical tests. Electrochemical tests show that corrosion potential （Ecorr） of Mg-2Zn-0.5Sr/HA composites significantly shifts toward nobler direction from -1724 to -1660 mVscE and the corrosion current density decreases from 479.8 to 280.8 ***^-2 with the addition of HA particles. Immersion tests show that average corrosion rate of ***/HA composites decreases from 11.7 to 9.1 mm/year with the addition of HA particles from 0 wt% up to 0.3 wt%. Both microstructure and mechanical properties can be attributed to grain refinement and mechanical bonding of HA particles with second phases and α-Mg matrix. Bio-corrosion behavior can be attributed to grain refinement and the formation of a stable and dense CaHPO4 protective film due to the adsorption of Ca^2＋ on HA particles. Our analysis shows that the Mg-2Zn-0.5Sr/0.3HA with good strength and corrosion resistance can be a good material candidate for biomedical applications.

关键词： Magnesium alloys Bio-composites Hydroxyapatite Microstructure Mechanical property Bio-corrosion behavior

Simulation and analysis of energy optimization for PEMFC hybrid system

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第11期7卷 1878-1885页

作者： LIU Cheng-ze ZHU xin-jian Department of Automation Shanghai Jiao Tong University Shanghai 200030 China

The control objective and several key parameters of PEMFC hybrid system are analyzed. Control strategy design and energy optimization simulation are made individually for given cycle case and realtime operating case. For the given cycle case, genetic algorithm is adopted to solve the multi-constraint combinatorial optimization problem. Simulation result showed the algorithm＇s feasibility. As far as the realtime operation is concerned, based on the original fuzzy control strategy, the fuel cell voltage and voltage variance parameters are introduced to apply result reveals that the improved fuzzy control strategy can enhance the two-level modification on the fuzzy control output. The fuel cell efficiency and reduce the power fluctuations.

关键词： PEMFC Hybrid system Energy optimization Fuzzy control

China＇s nuclear power under the global 1.5℃ target： Preliminary feasibility study and prospects

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2018年第2期9卷 138-143页

作者： XIAO xin-jian jianG Ke-Jun Energy Research Institute National Development and Reform Commission Beijing 100038 China

This study explores the measures to achieve the global 1.5 ℃ temperature rise target （1.5 ℃ target） by analyzing the feasibility and obstacles of nuclear power in China. The 1.5 ℃target imposes stricter requirements on China＇s nuclear power. Considering the available nuclear power plant sites, nuclear power layout, equipment manufacture ＆ supply, nuclear power plant construction capacity, supportive operation ＆ management talents, investment, cost effectiveness, and public acceptance, the achievement of the development objectives of nuclear power in China considering the 1.5 ℃ Target is difficult. However, it is possible if favorable decisions and policies are made.

关键词： 1.5 ℃ target Nuclear power in China Solutions Feasibility Decision-making

Lifted System Framework for Learning Control with Different Trial Lengths

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

International Journal of Automation and computing 2015年第3期12卷 273-280页

作者： Xue-Fang Li jian-xin Xu Department of Electrical and Computer Engineering National University of Singapore

This paper addresses an iterative learning control(ILC) design problem for discrete-time linear systems with randomly varying trial lengths. Due to the variation of the trial lengths, a stochastic matrix and an iteration-average operator are introduced to present a unified expression of ILC scheme. By using the framework of lifted system, the learning convergence condition of ILC in mathematical expectation is derived without using λ-norm. It is shown that the requirement on classic ILC that all trial lengths must be identical is mitigated and the identical initialization condition can be also removed. In the end, two illustrative examples are presented to demonstrate the performance and the effectiveness of the proposed ILC scheme for both time-invariant and time-varying linear systems.

关键词： Iterative learning control average operator randomly varying trial lengths identical initialization condition lifted sys-tem.