检索结果-南通市图书馆

Ecological hydraulic radius model to calculate instream flow requirements for transporting sediment in the western water transfer region

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2009年第11期52卷 3401-3405页

作者： MEN BaoHui1 & LIU ChangMing2 1 Renewable energy institute, North china Electric Power University, Beijing 102206, china 2 Key Laboratory of Water Cycle and Related Land Surface Process, institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, china 1. Renewable energy institute North China Electric Power University Beijing 102206 China 2. Key Laboratory of Water Cycle and Related Land Surface Process Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Transporting sediment is a natural function of the river. To maintain the normal evolution of the river certain amount of water flow is required, which is called the instream flow requirements for transporting sediment (IFRTS). We defined the permitting flow velocity by the conception of IFRTS, and also put forward the ecological hydraulic radius model (EHRM) to estimate IFRTS. The calculating process of EHRM is explained by the example of Daofu Hydrological Station on Xianshui branch of Yalong River in the west line first-stage construction of South-North Water Transfer Project. The result shows that the IFRTS occupied 29.7%―59.5% of annual mean discharge in flood season, the average of IFRTS was about 100.2 m3.s during 1966―1987, it is close to the IFRTS 90 m3.s calculated by IFRTS conception. Hence, it is feasible to use EHRM to calculate IFRTS.

关键词： ecological hydraulic radius model (EHRM) instream flow requirements for transporting sediment (IFRTS) permitting flow velocity ecological hydraulic radius for transporting sediment

Carbon emission permit allocation and trading

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 1999年第4期11卷 468-473页

作者： CHEN Wen\|ying, WU Zong\|xin (institute of Nuclear energy Technology, Tsinghua University, Beijing 100084, china) 清华大学核能技术设计研究院北京

Nowadays our earth is faced with grim challenge of global climate change. All countries should go into action jointly to mitigate climate change. Carbon emission permit allocation and trading are two important issues to realize global cooperation. In this paper two kinds of comprehensive carbon emission permit allocation methods not only considering equity but also efficiency were advanced. After the carbon permit price was determined, the trading situations in various regions or countries in the world and the global benefits gained from emission trading were expounded. Moreover, the impact of carbon emission permit trading on chinas economy was analyzed.

关键词： climate change carbon permit allocation carbon permit trading comprehensive allocation method

Quantitative amendment of high-field ^(13.C NMR spectra of coals

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第10期42卷 807-809页

作者： YANG Baolian, LI Liyun and YE ChaohuiLaboratory of Magnetic Resonance and atomic and Molecular Physics, Wuhan institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 43.071, china Laboratory of Magnetic Resonance and atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China

HIGH-RESOLUTION solid state 13. NMR spectroscopy has been a useful tool for the study of *** the use of cross polarization（CP）,magic angle spinning（MAS）and protonhigh-power decoupling（HPD）techniques,high-resolut... 详细信息

HIGH-RESOLUTION solid state 13./sup>C NMR spectroscopy has been a useful tool for the study of *** the use of cross polarization（CP）,magic angle spinning（MAS）and protonhigh-power decoupling（HPD）techniques,high-resolution solid state 13./sup>C NMR spectra ofcoals can be obtained and the coal aromaticity（fa）can be measured *** aromaticityis defined as the ratio of aromatic carbon atoms to the total carbon atoms in *** pa-

关键词： 13. NMR coal structure quantitative amendment.

D-Dimensional Dirac Fermions BEC-BCS Crossover Thermodynamics

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第7期48卷 99-106页

作者： CHEN Ji-Sheng institute of Particle Physics & Physics Department,Central china Normal University,Wuhan 43.079,china institute of Particle Physics Central China Normal University Physics Department Central China Normal University

An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions *** interior quantumfluctuation effects are incorporated as an external field approximation indirectly through a fictive generalized ThomsonProblem counterterm *** general analytical formulas for the d-dimensional thermodynamics are given nearthe unitary limit region,In the non-relativistic limit for d=3.the universal dimensionless coefficientε=4/9 andenergy gap △/ε_f=5/18 are reasonably consistent with the existing theoretical and experimental *** the unitarylimit for d=2 and T=0,the universal coefficient can even approach the extreme occasion ξ=0 corresponding to theinfinite effective fermion mass m~*=∞,which can be mapped to the strongly coupled two-dimensional electrons and isquite similar to the three-dimensional Bose-Einstein condensation of ideal boson ***,for d=1,the universalcoefficient ξ is negative,implying the non-existence of phase transition from superfluidity to normal *** solutionsmanifest the quantum Ising universal class characteristic of the strongly coupled unitary fermions gas.

关键词： unitary fermions thermodynamics BEC-BCS crossover statistical methods

在线全文

学校读者我要写书评

暂无评论

关于先进核能系统的经济性

核科学与工程 1998年第4期18卷 289-296页

作者： LI SHOUNAN (china institute of atomic {3.) (Manuscript received 8 August,1997) 中国原子能科学研究院

从中子经济性角度对不同先进核能系统的嬗变（或增殖）经济性作初步分析和比较

关键词：先进核能系统嬗变中子经济性增殖

Characterization of microarc oxidation coatings on pure titanium

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2003年第1期22卷 42-48页

作者： XUE Wenbin, WANG Chao, Li Yongliang, and CHEN RuyiKey Laboratory for Beam Technology and Materials Modification, institute of Low energy Nuclear Physics, Beijing Normal University, Beijing 100875, china 北京师范大学射线束技术与材料改性教育部重点实验室北京 100875

Key Laboratory for Beam Technology and Materials Modification, institute ofLow energy Nuclear Physics, Beijing Normal UniversityThe morphology, composition, and phase structure of the oxide coatings produced on the surface ofpure titanium by alternating-current microarc discharge in aluminate solution were investigated byX-ray diffraction and scanning electron microscopy. The profiles of the hardness H and the elasticmodulus E in the coatings were determined using a nanoindentation method. The concentrationdistributions of Ti, Al, and O in the coating show that this coating over 3. mu m thick contains twolayers: an outer layer and an inner layer. The oxide coating is mainly composed of TiO_2 rutile andAl_2TiO_5 compounds. During oxidation, the temperature in the microarc discharge channel was veryhigh to make the local coating molten. From the surface to the interior of the coating, H and Eincrease gradually, and then reach maximum values of 9.78 GPa and 176 GPa respectively at a distanceof 7 mu m from the coating/titanium interface. They are also rather high near the interface.

关键词： pure titanium ceramic coating microarc oxidation microstructure nanoindentation

THE SOLUTION OF A PARAMETERIC EQUATION ARISING IN TRANSPORT THEORY

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1989年第1期2卷 92-96页

作者：杨斌阳名珠 institute of atomic energy BeijingChina

This paper deals with the solution of a neutron transport equation with parameter δ.Usingthe theory of functional analysis,we discuss the distribution of the parameters which make the equationhave a non-zero solution,and obtain a necessary and sufficient condition for the existence of thecontrol critical eigenvalue δ0 which possesses a physical meaning.

关键词： Transport equation δ-eigenvalue compact operator positive definite operator

Surface investigation on Upilex-S polymide film iradiated by vacuum ultraviolet radiation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第S1期26卷 168-174页

作者： LIU Yuyan1),GONG Xianyun2),WAN Zhimin3.,and DU Xingwen4)1) Department of Applied Chemistry,Harbin institute of Technology,Harbin 150001,china 2) Department of Life Science and Chemistry,Harbin University,Harbin 150001,china 3. Analysis and Measurement Center,Harbin institute of Technology,Harbin 150001,china 4) Center for Composite Materials,Harbin institute of Technology,Harbin 150001,china Harbin Inst Technol Dept Appl Chem Harbin 150001 Peoples R China Harbin Univ Dept Life Sci & Chem Harbin 150001 Peoples R China Harbin Inst Technol Ctr Anal & Measurement Harbin 150001 Peoples R China Harbin Inst Technol Ctr Composite Mat Harbin 150001 Peoples R China

Vacuum ultraviolet radiation of Upilex-S polyimide film 25 μm thick was performed using a gas jet type of vacuum ultraviolet simulator which gives unfixed wavelength from 5 nm to 200 *** redeposited on the films were observed and the nanoparticles formed on the surface consist mainly of carbon *** in the composition and the chemical characteristics of film surface after radiation were identified by X-ray photoelectron spectroscopy(XPS).Relative O content in the radiated area was found to be higher,while N content was lower than in the pristine *** indicates that Upilex-S polyimide film releases N atoms as volatile *** the C1s,O1s envelopes were fitted using Multipak Spectrum *** surface morphologies on iradiated area were examined by atomic Force Microscope(AFM).Pieces of radiant products protrude from the eradiated surface,leading to considerable roughness for the iradiated *** the surface transmittance of Upilex-S film after radiation reduces.

关键词： vacuum ultraviolet radiation Upilex-S polyimide film

The State-of-Art and Development Trends of HSLA Steels in china

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 1-13页

作者： WENG Yu-qing 1,YANG Cai-fu 2,SHANG Cheng-jia 3.(1.The Chinese Society for Metals,Beijing,PR china 2.Centre Iron and Steel Research institute,Beijing,PR china 3.University of Science and Technology Beijing,Beijing,PR china) Chinese Soc Met Beijing Peoples R China Ctr Iron & Steel Res Inst Beijing Peoples R China Univ Sci & Technol Beijing Beijing 100083 Peoples R China

During the last decade,the adjustment of product segments always is a very important task of iron industry,and upgrading of steel products has been impelled actively by Chinese iron and steel *** rapidly increasing of iron & steel production,a series of research achievements have been made in the technology area of high strengthtoughness steel,and also have been applied successfully in the actual production,*** technology of fine grain and ultra-fine grain steels,the technology for the control of microalloying ***,It is an important strategic goal of "Twelfth Five-year Plan" for Chinese iron and steel industry that the adjustment of steel product segments and meeting the requirements for upgrading of domestic and oversea equipment manufactory *** HSLA steel with better performance,instead of plain steel,could save steel consumption largely,and also release pressures from resource,energy and *** doubt,it is the only way to realize the sustained development of Chinese iron and steel industry by popularizing the application of HSLA steels vigorously.

关键词： HSLA steel microalloying technology Chinese iron and steel industry