检索结果-南通市图书馆

Study on Water Consumption Coefficient of People's Living and Its Regional Disparity in the North of china

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,resources and Environment 2005年第2期3卷 20-26页

作者： Wang Jing’ai 1-3, Mao Rui 3,4, Yang Mingchuan 3,4 & Zhou Junju 11 College of Geography & Remote Sensing 2 key laboratory of Regional Geography of beijing Normal University 3 key laboratory of Environmental Change and Natural Disaster of ministry of education of china 4 College of resources Science & Technology, beijing Normal University, beijing 100875, china College of Geography and Remote Sensing Beijing 100048 China key laboratory of Environmental Change and Natural Disaster of ministry of education of china Beijing 100048 China College of resources Science and Technology Beijing Normal University Beijing 100875 China

By employing the information-reshufflingmethod that integrates census data, precipitation dataand inquiry data of water consumption, this paperdiscusses 5 (water consumption coefficient of people’sliving) in allusion to different precipitation zones anddifferent periods of time. The study shows that 5-(water consumption coefficient of urban people’sliving), 5. (water consumption coefficient of ruralpeople’s living) and increase with time passing, andthe increasing extent of 5 is 1.84, 2.62, 2.84 and 2.68times respectively from the west to the east, whichresults from the total quantity of water resources andthe speed of urbanization. 5- and 5. of eachprecipitation zone increased with 5- increasing morequickly than 5., and the difference between the twoalso increased when time passed. In the past fifty years(1950-2000), the increasing extent of 5- was 1.71,2.96, 2.41 and 2.33 times respectively from the westto the east, in which 200-400mm precipitation zoneincreased more than others. Meanwhile the increasingextent of 5. is 1.55, 1.60, 1.53 and 1.64 timesrespectively from the west to the east with eachprecipitation zone increasing similarly. The change of5-is due to the speed of urbanization and the stabilityof water resources. This study provides basis forcalculating the water demand of people’s living andrevealing the impact of water demand of people’s livingon ecological drought in different zones.

关键词： The north of china precipitation zone water consumption coefficient of people’s living

Stratigraphic thermohistory and its implications for regional geoevolution in the Tarim Basin,NW china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第10期53卷 1495-1505页

作者： WANG TieGuan1,DAI ShiFeng2,LI MeiJun1,ZHANG WeiBiao1,3,Qiu NanSheng1 & WANG GuangLi1 1 State key laboratory of Petroleum resources and Prospecting,china University of Petroleum,beijing 102249,china 2 State key laboratory of coal resources & Safe Mining,china University of Mining & Technology,beijing 100083,china 3 Exploration Research Center,Exploration & Development Institute,china Petrochemical Corporation,beijing 100083,china State key laboratory of Petroleum resources and Prospecting China University of Petroleum Beijing China State key laboratory of coal resources & Safe Mining China University of Mining & Technology Beijing China Exploration Research Center Exploration & Development Institute China Petrochemical Corporation Beijing China

Fourteen vitrinite reflectance profiles from the Tarim Basin,NW china,show that the vitrinite reflectance profiles of individual wells follow a faulted and dislocated dual-stage pattern in the eastern section of the Tazhong Uplift and in the Tabei *** reflectance values in these profiles change sharply at the unconformity beneath the Lower Carboniferous Bachu or Upper Devonian Donghetang Formations,where the overlying Triassic to Carboniferous strata are still in a mature phase within the "liquid oil window".However,the underlying Lower Paleozoic reached the overmature phase beyond the "liquid oil window" towards the end of the Silurian,or in the Early Devonian at the *** the vitrinite reflectance profiles are attributed to a continuous,single-stage pattern in the western section of the Tazhong Uplift,in which the Lower Paleozoic is also in an overmature phase,their overmaturity would have been achieved relatively late in geological *** stratigraphic thermohistory has the following implications to regional geoevolution:(1) The overmature Lower Ordovician to Cambrian strata in the eastern section of the Tazhong Uplift and in the Tabei Uplift,as well as in the Manjiaer Depression,could not have acted as the source kitchen for normal oil(so-called black oil);(2) The dissimilarity in vitrinite reflectance profiles between the eastern and western sections of the Tazhong Uplift reveals Early Paleozoic paleotectonic features,i.e.,lower at the east and higher at the west,whereas recent tectonic features formed since the Late Paleozoic are in reverse,i.e.,higher in the east and lower at the west;(3) Reconstruction of the denuded thickness of sediments overlying the Lower Ordovician strata suggests reconsideration on the paleotectonic features in the Tarim Basin;(4) Based on the sustained duration of the "liquid oil window" for overmature source beds,it is predicted that the Suntuoguole Lower Uplift between the Awati and Manjiaer Depressions is a

关键词： vitrinite reflectance profile faulted and dislocated dual-stage pattern paleotectonic features sustained "liquid oil window" period source kitchen

Research on Trace Elements Geochemistry of Ordovician Carbonates in Tazhong area,Tarim Basin

在线全文

学校读者我要写书评

暂无评论

地学前缘 2009年第S1期16卷 145-146页

作者： Huajun Wang,Wenhui Huang,Kuangming Zhang,Min Yang School of Energy resources,china University of Geosciences(beijing) key laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,ministry of education,beijing 100083,china.

The research on the trace elements of Ordovician carbonates plays an important role in the whole research work on reservoir in Tazhong *** work applies ICP-MS,which is a new trace elements analysis technology to measure contents of different elements,systematically in the studies of the characteristics and sedimentary settings of Ordovician dolomites in Tazhong area,Tarim Basin,and argues for their enrichment mechanisms and different elements existing *** results show that there is a close relationship between geochemistry charac-

关键词： dolomite sedimentary settings geochemistry trace elements

Energy analysis for damage and catastrophic failure of rocks

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2011年第S1期54卷 199-209页

作者： XIE HePing 1,2,LI LiYun 2,1,JU Yang 2,PENG RuiDong 2 & YANG YongMing 2 1 Sichuan University,Chengdu 610065,china 2 State key laboratory of coal resources and Safe Mining,beijing key laboratory of Fracture and Damage Mechanics of Rock and Concrete,china University of Mining and Technology,beijing 100083,china Sichuan University State key laboratory of coal resources and Safe Mining Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete China University of Mining and Technology

The development history and current state of studies on the characteristics and mechanisms of deformation and failure of rock materials were briefly reviewed from the viewpoint of *** main scope and the achievable objectives of the energy-based research system were *** was validated by experiments that the damage process of rocks can be well described by the rock damage evolution equation established based on energy *** was found from the uniaxial compression and biaxial compression tests that only a small proportion of the total input energy in hard rocks is dissipated before peak load and a large proportion in soft rocks is dissipated before peak *** both hard and soft rocks,the energy dissipated after peak load accounts for a greater *** energy would be required for rock failure under equal biaxial compression than under unequal biaxial *** total absorbed energy is different for rock failure under high-rate loading and low-rate *** fragmented failure pattern usually corresponds to higher energy *** mesoscopic analysis on the damage and failure of bedded salt rocks showed that the energy dissipation is prominent and the total absorbed energy for rock failure is low when cracks propagate in the weak mud interlayer while it is contrary when cracks propagate in the salt *** energy accumulation,transfer,dissipation and release during the failure process of tunnel with impending failure under disturbance were analyzed theoretically based on the elastoplastic mechanics ***,the spatial distribution of energy dissipation and energy release of fractured rocks under unloading was simulated *** was demonstrated that energy is likely to be released from the weakest surface under compression,which triggers the global failure of rocks.

关键词： rock deformation failure energy accumulation energy dissipation energy release

Refraction of light in media

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 591-600页

作者： ZHANG Tao key laboratory of Beam Technology and Material Modification of ministry of education, Institute of Low Energy Nuclear Physics, beijing Normal University, beijing 100875, china beijing Radiation Center, beijing 100875, china key laboratory of Beam Technology and Material Modification of ministry of education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China

The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium. The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s Law is applied to this conductor that is in the alternating magnetic field of the light. dBM/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy, i.e. the refractive energy, with the elec- tron cloud conductor. Formulas of refractive index, which is the ratio of light speed in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.

关键词： refractive index, light, speed, medium, propagation

Effects of flexibility on aerodynamic performance of delta wings with different sweep angles

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 915-922页

作者： LIU Yang,ZUO LinXuan & WANG JinJun Institute of Fluid Mechanics,beijing University of Aeronautics and Astronautics and Fluid Mechanics key laboratory,ministry of education,beijing 100191,china Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics Fluid Mechanics key laboratory Ministry of Education

Force measurement and surface oil flow visualization experiments were conducted in a wind tunnel to investigate the effects of flexibility on aerodynamic performance of delta wings with different sweep *** experimental results indicate that the maximum lift coefficient is increased and the stall angle is delayed as the sweep angle increases for both rigid and flexible *** is also found that the maximum lift coefficients of the flexible wings with a sweep angle from 35° to 50° are higher than those of the rigid *** increment of the maximum lift coefficient in particular achieves 32.9% compared with the case without lift enhancement for the 40° flexible delta ***,the surface oil flow visualization experiments show that the stall of the flexible wing of the moderate low sweep angle is accompanied by helical flow structure,while the vortex bursting appears on the corresponding rigid wing.

关键词： delta wing wing flexibility aerodynamics sweep angle

Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3 & ZHANG XiaoZhong4,5 1 key laboratory of Beam Technology & Materials Modification of the ministry of education, Institute of Low Energy Nuclear Physics, beijing Normal University, beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3 laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, beijing 100080, china 4 key laboratory of Advanced Materials of the ministry of education, Department of Materials Science and Engineering, Tsinghua University, beijing 100084, china 5 beijing National Center for Electron Microscopy, Tsinghua University, beijing 100084, china key laboratory of Beam Technology & Materials Modification of the ministry of education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing China key laboratory of Advanced Materials of the ministry of education Department of Materials Science and Engineering Tsinghua University Beijing China beijing National Center for Electron Microscopy Tsinghua University Beijing China

The LaMn1-xTexO3+δ (x=0.1, 0.2, 0.3) were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3+ ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3+ and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3+ is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3+ is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

An ecological hydraulic radius approach to estimate the instream ecological water requirement

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第3期17卷 320-327页

作者： LIU Changming and MEN Baohui ( 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 key laboratory of Water and Sediment Sciences, ministry of education & Water Sciences College, beijing Normal University, beijing 100875, china Department of Hydraulic and Hydropower Engineering, North china Electric Power University, beijing 102206, china) 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. key laboratory of Water and Sediment Sciences Ministry of Education & Water Sciences College Beijing Normal University Beijing 100875 China. Department of Hydraulic and Hydropower Engineering North China Electric Power University Beijing 102206 China

This essay defines the concepts of ecological flow velocity as well as ecological hydraulic radius (EHR) and proposes an ecological hydraulic radius approach (EHRA) which considers both the watercourse information (including hydraulic radius, roughness coefficient and hydraulic gradient) and the required stream velocity necessary for maintenance of certain ecological functions all together. The key parameter of EHRA is to fix the watercourse cross-sectional flow area corresponding to EHR, by which the relation between parabola shaped cross-sectional flow area and hydraulic radius is deduced. The EHRA not only meets the requirement of flow velocity for adequate fish spawning migration, but also is applicable to the ecological flows in regard with other ecological issues (such as the calculation of the instream flow requirements for transporting sediment and for pollution self-purification, etc.). This essay has illuminated the computational process taking the estimation of ecological water requirement of Zhuba Hydrologyical Station watercourse in Niqu branch of the Yalong River as an example. Additionally, we compare EHRA with Tennant approach. The result shows that the Zhuba Hydrological Station ecological water requirement calculated by EHRA lies between the minimum and favorable ecological water requirement calculated by the Tennant approach. This is due to the fact that the ecological flow velocity (such as the fish spawning migration flow velocity) was taken into consideration, producing results applicable to the practical situation.

关键词： ecological flow flow velocity cross-sectional flow area ecological hydraulic radius (HER) instreamecological water requirement.

Redevelopment of liftoff rates of saltating sand grains based on a simple optimization model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第4期53卷 568-574页

作者： CHENG Hong & ZOU XueYong State key laboratory of Earth Surface Processes and Resource Ecology,beijing Normal University,beijing 100875,china MOE Engineering Center of Desertification and Blown-sand Control,beijing Normal University,beijing 100875,china key laboratory of Environmental Change and Natural Disaster of the ministry of education of china,beijing Normal University,beijing 100875,china State key laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing China MOE Engineering Center of Desertification and Blown-sand Control Beijing Normal University Beijing China key laboratory of Environmental Change and Natural Disaster of the ministry of education of china Beijing Normal University Beijing China

This paper is a redevelopment result of liftoff rates of saltating sand grains based on our previous *** sand flow is a complex multi-phase flow because of a special two-phase gas-solid flow near ground *** extensive research on the movement of blowing sand,no model fully characterizes aeolian sand flow,and large differences often exist between simulations of aeolian sand movement and field *** key problem is a few of sufficient research on liftoff rates of saltating sand grains(also called the number of liftoff sand grains per unit time and per unit bed area).It is necessary to re-search in advance liftoff rates of saltating sand *** redeveloped liftoff rates of saltating sand grains by establishing an optimization model based on the flux of aeolian sand flow at different heights of the sampler in wind tunnel and the simulated capture of saltating sand grains by different heights of the sampler that are from different liftoff position(distance from the sampler) in order to revise previous inversion condition of liftoff rates of saltating sand *** rates increased rapidly with increasing wind *** frictional wind velocities of u=0.67,0.77,0.82,0.83,and 0.87 m s-1,liftoff rates were 3840,954502,5235114,5499407,and 7696291 sand grain s-1 m-2,*** rates could be expressed as the square of the instantaneous frictional wind velocity and a constant(0.663) that differs from the critical(threshold) frictional wind velocity at which saltation *** our results require additional experimental validation and the simple optimization model must be improved,they nonetheless provide a strong basis for future research.

关键词： liftoff rates of saltating sand grains optimization model wind tunnel two-phase gas-solid flow