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γ-Radiation synthesis of nanocrystalline nickel powder from nickel (Ⅱ ) -ammonia complex solution

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Chinese science Bulletin 1997年第8期42卷 644-648页

作者： ZHU Yingjie, QIAN Yitai and ZHANG Manwei1. department of Applied Chemistry, university of {2. and Technology of china, Hefei 2.002., china 2. Structure Research Laboratory, university of {2. and Technology of china, Hefei 2.002., china Departnient of Applied Chemistry University of Scirnce and Technology of China Hefei China Structure Research I.aboratory University of Science and Technology of China Hefei China

NANOCRYSTALLINE nickel is very important for its applications in the fields such as catalysis andmagnetic *** usual method used for preparing nanocrystalline nickel is inert gas e-vaporation,which requires high ***,high temperature easily leads tothe growth or oxidation of nickel *** et *** the nickel microaggre-gates dispersed in solution produced by γ-irradiating a dilute solution of Ni2.

关键词： nickel nanocrystalline powder γ-radiation.

Human remains and the environment of Early Pleistocene in the Nihewan Basin

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science china Earth sciences 2004年第5期47卷 437-444页

作者： CAI Baoquan1 & LI Qiang2.1. department of History, Xiamen university, Fujian 361005,{2. 2. Institute of Vertebrate Palaeontology and Palaeoanthropology, Chinese Academy of sciences, Beijing 100044,{2. Xiamen Univ Dept Hist Fujian 361005 Peoples R China Chinese Acad Sci Inst Vertebrate Paleontol & Paleoanthropol Beijing 100044 Peoples R China

A new Early Pleistocene Paleolithic site was found in July 2.01 in the Nihewan Ba-sin, Hebei Province. Totally 500 mammal specimens assigned to 2. species and 5 lithic artifacts were collected. The coexistence of Allophaiomys deucalion, Borsodia chinensis and Yangia tingi provides important evidence of chronology. On the basis of the comparison of mammalian fauna, the date of Paleolithic artifacts is probably earlier than 1.8 MaBP, possibly 2.0 MaBP. This is the earliest evidence of hominid activity found so far in North china. The hominid at that time in the Nihewan Basin lived in an environment of arid grasslands with scattered trees of temperate zone. This discovery is significant to the study of human origin and cultural development.

关键词： human remains, environment, Early Pleistocene, Nihewan.

A relative local variational principle for topological pressure

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science china Mathematics 2010年第6期53卷 1491-1506页

作者： MA XianFeng1,CHEN ErCai2.3,& ZHANG AiHua2.4 1department of Mathematics,East china {2. of science and Technology,Shanghai 2.02.7,china 2.chool of Mathematics and computer science,nanjing Normal {2.,nanjing 2.0097,china 3Center of Nonlinear science,nanjing {2.,nanjing 2.0093,china 4College of Mathematics and Physics,nanjing {2. of Posts and Telecommunications,nanjing 2.0046,china 1. department of Mathematics East China University of Science and Technology Shanghai 200237 China2. School of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China3. Center of Nonlinear Science Nanjing University Nanjing 210093 China4. College of Mathematics and Physics Nanjing University of Posts and Telecommunications Nanjing 210046 China

We define the relative local topological pressure for any given factor map and open cover,and prove the relative local variational principle of this *** precisely,for a given factor map π:(X,T)→(Y,S) between two topological dynamical systems,an open cover U of X,a continuous,real-valued function f on X and an S-invariant measure ν on Y,we show that the corresponding relative local pressure P(T,f,U,y) satisfies sup μ∈M(X,T){ hμ(T,U|Y)+∫X f(x)dμ(x) :πμ=ν}=∫Y P(T,f,U,y)dν(y),where M(X,T) denotes the family of all T-invariant measures on ***,the supremum can be attained by a T-invariant measure.

关键词： pressure conditional entropy relative local variational principle

On critical values concerning the evolution of the long period families

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Chinese Journal of Astronomy and Astrophysics 2009年第4期9卷 494-500页

作者： Xi-Yun Hou1,2. Astronomy department, nanjing {2., nanjing 2.0093, china 2.Institute of Space Environment and Astronautics, nanjing {2., nanjing 2.0093, china Astronomy department Nanjing University Nanjing 210093 China Institute of Space Environment and Astronautics Nanjing University Nanjing 210093 China

In a previous paper, we proposed another special critical value concerning the evolution of the long period family around the equilateral equilibrium points, besides the two values given by Henrard. Are there any other special critical values？ After studying the stability curves of the long period family carefully, we gave a negative answer. During the study, we found an interesting family of periodic orbits which we called the homo family. We studied the evolution of this family following the increase of μ. With these findings, we were able to explain the origin of the four branches of periodic families emanating from L4 and the stability results of the equilateral equilibrium points.

关键词： celestial mechanics

Numerical study on optical and electric-thermal performance for solar concentrating PV/T air system

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science china(Technological sciences) 2009年第12期52卷 3514-3520页

作者： SUN Jian 1,2.&SHI MingHeng 1 1School of Energy and Environment,southeast university,{2. 2.0096,china 2.5} of Thermal Energy Engineering,Jingdezhen Ceramic Institute,Jingdezhen 333001,china 1. School of Energy and Environment Southeast University Nanjing 210096 China 2. department of Thermal Energy Engineering Jingdezhen Ceramic Institute Jingdezhen 333001 China

Hybrid photovoltaic/thermal(PV/T)system with solar concentrator is an effective way to improve solar energy conversion *** this work,a single-pass PV/T air system with a three-trough compound parabolic concentrator(CPC)of concentration ratio 2.0 is designed and the solar incident distributions at the solar cell surface are calculated by ray tracing *** on energy balance,the heat transfer models of all main components in this system are *** effects of some main designing and operational parameters on the electric-thermal performance of the system are analyzed. The results show that the solar radiation intensity can be higher than 12.0 W/m 2.at most area of the cell *** temperature of the air and cell surface increases along the length of the *** the system efficiency of the CPC is higher than that of the system without the *** thermal efficiency, exergy and electrical efficiency of this CPC system increase with increasing of the air mass flow rate and the length of the *** increasing packing fraction the electrical efficiency increases,but the thermal efficiency *** exergy efficiency increases slightly with the packing fraction *** data obtained in this work are valuable for the design and operation for this kind of solar concentrating PV/T systems.

关键词： photovoltaic/thermal system CPC exergy efficiency thermal and electricity performance optical

Existence of the solutions and the attractors for the large-scale atmospheric equations

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science china Earth sciences 2006年第6期49卷 650-660页

作者： HUANG Haiyang1 & GUO Boling2.1. department of Mathematics, Beijing Normal university, Beijing 100875,{2. 2. Institute of Applied Physics and Computational Mathematics, Beijing 100080,{2. 1. department of Mathematics Beijing Normal University Beijing 100875 China 2. Institute of Applied Physics and Computational Mathematics Beijing 100080 China

In this paper, firstly, the proper function space is chosen, and the proper expression of the operators is introduced such that the complex large-scale atmospheric motion equations can be described by a simple and abstract equation, by which the definition of the weak solution of the atmospheric equations is made. Secondly, the existence of the weak solution for the atmospheric equations and the steady state equations is proved by using the Galerkin method. The existence of the non-empty global attractors for the atmospheric equations in the sense of the Chepyzhov-Vishik’s definition is obtained by constructing a trajectory attractor set of the atmospheric motion equations. The result obtained here is the foundation for studying the topological structure and the dynamical behavior of the atmosphere attractors. Moreover, the methods used here are also valid for studying the other atmospheric motion models.

关键词： atmosphere equations, weak solution, trajectory attractor, global attractor, equilibrium.

Special magnetic phenomena in heavily doped La_(0.7-x)Dy_xSr_(0.3)MnO_3 system

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science china(Physics,Mechanics & Astronomy) 2008年第1期51卷 90-97页

作者： LIU Ning 1,2.,YAN GuoQing 1,3 ,CAI ZhiRang 1 ,PI Li 2.,ZHANG Bei 2.&TONG Wei 2.1 department of Physics,Suzhou College,Suzhou 2.4000,china 2.Structure Research Laboratory,{2. of science and Technology of china,Hefei 2.002.,china 3 National Laboratory of Solid State Microstructures,Physics department,nanjing {2.,nanjing 2.0093,china 1. department of Physics Suzhou College Suzhou 234000 China 2. Structure Research Laboratory University of Science and Technology of China Hefei 230026 China 3. National Laboratory of Solid State Microstructures Physics Department Nanjing University Nanjing 210093 China

The magnetism in heavily Dy doped La0.7-xDyxSr0.3MnO3(0.40≤x≤0.70)system is studied in this *** M-T relation seems to be complicated with the increase of *** sample with x=0.40,AFM behavior exists at T≤TN and M-T curves under zero field cooling(ZFC)and field cooling(FC)exhibit typical behavior of spincluster glass state above *** the sample with x=0.50,the M-T curve under ZFC exhibits a valley at a low temperature while the M-T curve under FC exhibits the negative magnetization below *** samples with x=0.60,0.70,their ZFC M-T curves are similar to that of x=0.50,but the FC M-T curves do not exhibit negative values any *** the peculiar phenomena above are well explained by Néel double-lattice model combined with M-H relation at typical *** molecular field theory fits well the negative magnetization for x=0.50.

关键词： heavily doped special magnetic phenomena double-lattice model

Application of vertically integrated sampling approach to study of new production via ^(2.4)Th -^(2.8)U disequilibria

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Acta Oceanologica Sinica 2000年第2期19卷 37-44页

作者： Chen Feizhou1 Huang Yipu2.Chen Min2.(1. College of Fishery science, Shanghai Fisheries university, Shanghai 2.0090,{2. 2. department of Oceanography, Xiamen university, Xiamen 361005,{2.) College of Fishery science Shanghai Fisheries University Shanghai 200090 China

The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~2.4Th/ ~2.8U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South china Sea. The scavenging fluxes and removal fluxes of ~2.4Th and the residence times for dissolved and particulate ~2.4Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(2.4)Th - ^(2.8)U disequilibria in large spatial scale.

关键词： New production vertically integrated Sampling approach, ^(2.4)Th - ^(2.8)U disequilibria Xia men Bay northern South china Sea

The history of crustal uplift and metamorphic evolution of Panzhihua-Xichang micro-palaeoland, SW china:Constraints on Sm-Nd, ^(40)Ar/^(39)Ar and FT ages of granulites

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science china Earth sciences 2004年第8期47卷 689-703页

作者： XU Shijin1, LIU Wenzhong1, WANG Rucheng1, YU Hangbo1, LI Daming2. WAN Jinglin2.& FANG Zhong1 1. department of Earth sciences and State Key Laboratory for Mineral Deposits Research, {2. university, {2. 2.0093, china 2. Institute of Geology, china Seismological Bureau, Beijing 10002., china 1. department of Earth sciences and State Key Laboratory for Mineral Deposits Research Nanjing University 210093 Nanjing China 2. Institute of Geology China Seismological Bureau 100029 Beijing China

Panzhihua-Xichang (Panxi) micro-palaeoland is the oldest terrane on the western margin of the Yangtze Block. Some intermediate-basic granulites are considered to be the crys-talline basement of lower crust in the terrane. Granulite-facies metamorphism of the granulites was developed in the period from 1186 Ma to 112. Ma. The origin of granulites was related to the collision orogenic process occurring when the micro-palaeolands merged to form the Rodinia Supercontinent. Amphibolite-facies retrogressive metamorphism of granulites took place in the period from 877 Ma to 82. Ma. This period was consistent with the breakup time of the Rodinia Supercontinent. 40Ar/39Ar ages and fission track (FT) ages of granulites in the Panxi mi-cro-palaeoland show that the vertical movement history of crustal rocks was a slow uplift process of the rigid terrane in the time from Neoproterozoic to Mesozoic. The subduction of India Plate towards Euroasia Plate resulted in the rapid uplift of the Qinghai-Tibetan Block in Cenozoic. Meanwhile, the Qinghai-Tibetan Block moved towards east. Consequently the Panxi terrane was uplifted rapidly. As a result of the collision orogeny between the Qinghai-Tibetan Block and the Panxi terrane, the granulite-facies crystalline basement in this region was exhumed and exposed to the surface.

关键词： granulite,isotope geochronology,crustal uplift movement,Panzhihua-Xichang region,western margin of Yangtze Block.