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Palaeorunoff estimations achieved from palaeoclimatic information for the southwest part of the North China Plain: an attempt to apply a climatological approach to palaeohydrology

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Journal of Environmental Sciences 2000年第3期12卷 330-336页

作者： WANG Hong\|ya, XIE Qiang (department of Urban and Environmental Sciences, peking university,{2. 100871, China) 北京大学北京 1 0 0 871

Palaeoclimatic scenario projecting annual temperature and annual precipitation is firstly formalized with data available and speculations for the southwest part of the North China Plain (35— 37°N, 115—119°E) during the last 2.000 years. Then, with three regression equations relating annual runoff to annual precipitation and derived with data of modern hydrological and meteorological records, values of annual runoff are calculated in terms of the corresponding values of annual precipitation from this palaeoclimatic scenario for this region during this temporal interval. These results indicate that runoff is the most during 8000—3000 a B.P. and the least during 2.000—12.00 a B.P.; runoff occurring during 12.00—8000 a B.P. and during 3000—0 a B.P. is less than the one occurring during 8000—3000 a B.P. and more than the one occurring during 2.000—12.00 a B.P.; and the runoff occurring during 2.000—12.00 a B.P., 12.00—8000 a B.P., and 3000—0 a B.P. is respectively 43, 46 and 66 percent of the one occurring during 8000—3000 a B.P. Values of bankfull discharge for palaeochannels of the Yellow River flowing in this region during the same interval are calculated from available estimates of slope of stream bed of these palaeochannels with a regression equation relating bankfull discharge to slope of stream bed and ratios of bankfull discharge are further calculated from these values for different groups of palaeochannel formed during different time spans embraced in this interval. To conduct a cross check, these values and ratios of bankfull discharge are compared to the corresponding values and ratios of runoff occurring during roughly the same time spans. The same direction and similar relative magnitude of changes of the surface water occurring in this region during the last 2.000 years are indicated by these comparisons.

关键词： palaeorunoff the southwest part of the North China Plain palaeoclimate

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Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process

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Science China Earth Sciences 2004年第2期47卷 138-150页

作者： ZHANG Jinjiang, Jl Jianqing, ZHONG Dalai, DING Lin & HE Shundong1. department of Geology, peking university,{2., China 2. Institute of Geology and geophysics, Chinese Academy of Sciences, beijing 10002., China Correspondence should be addressed to Zhang Jinjiang (email: zhjj@***) 1. department of Geology Peking University 100871 Beijing China 2. Institute of Geology and geophysics Chinese Academy of Sciences 100029 Beijing China

The structural pattern of the eastern Himalayan syntaxis in Namjagbarwa consists of two series of structures with different styles. One series compiles the earlier ductile contractional and lateral-slip deformation system, formed by nearly north-south shortening within the syntaxis, left-lateral and right-lateral slipping along its western and eastern boundaries respectively. They were possibly produced by the indentation of the Indian continent into Asian continent after India-Asia collision. The peak deformation-metamorphic ages in these structures are 62.60 Ma, ~2. Ma and ~13 Ma. The other series is composed of ductile-brittle normal faults distributing concentrically and dipping toward the outsides of Namjagbarwa Peak. They were probably the collapse structures caused by rapid uplift in a later time and the beginning ages for the normal faulting are about 7.3-6.3 Ma. Keywords Namjagbarwa - eastern Himalayan syntaxis (EHS) - structural pattern - formation process - structural chronology

关键词： Namjagbarwa, eastern Himalayan syntaxis (EHS), structural pattern, formation process, structural chronology.

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|m| Partial wave treatment for two-dimensional Coulomb-scattering and Regge pole

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Science China(Physics,Mechanics & Astronomy) 2004年第6期47卷 676-684页

作者： WANG Jing & ZENG Jinyan department of Physics,Tsinghua university,{2. 100084,China School of Physics,peking university,{2. 100871,China department of Physics Tsinghua University Beijing 100084 China School of Physics Peking University Beijing 100871 China

The symmetry and |m| partial-wave analysis for two-dimensional (2.) Coulomb-scattering is investigated. As a function of energyE, the |m| partial-wave scattering amplitudef |m|(θ) is analytically continuated to the, negativeE (complexk) plane, and it is found that the bound state energy eigenvalues (E<0) are just located at the poles off |m|(θ) on the positive imaginaryk axis as is expected. In addition, as a function of |m|,f |m|(θ) is analytically continuated to the complex |m| plane, the bound state energy eigenvalues are just located at the poles off |m|(θ) on the positive real |m| axis.

关键词： two-dimensional Coulomb scattering, |m| partial-wave, Regge pole.

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AutoProc: An automatic proactive replication scheme for P2. storage

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Science China(Information Sciences) 2011年第6期54卷 1151-1160页

作者： YANG Zhi & DAI YaFei Computer Science department, peking university,{2., China 1. Computer Science department Peking University Beijing 100871 China

Due to the prevalence of peer departures, P2. storage systems need to constantly generate replicas for high durability. However, few existing systems are able to select the right replication rate that balances replication cost and durability, e.g., minimizing replication cost without threatening the durability target. In this paper, we propose a method called AutoProc to automate the replication process in P2. storage systems. AutoProc employs two key techniques to enable cost-effective replication: correctly adapting replication rate with a reliability model, and replicating objects at the right order with a reliability indicator. Extensive simulations based on the real system failure trace show that AutoProc achieves the near-optimal performance.

关键词： P2. storage churn durability fault tolerance proactive replication resource usage

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Pole assignment in descriptor periodic systems

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Science China Mathematics 2005年第10期48卷 1309-1332页

作者： FAN Hung-Yuan~1 LIN Wen-Wei~1 & XU Shufang~2.1. department of Mathematics,Tsing Hua university,Hsinchu 30043,China 2. LMAM,School of Mathematical Sciences,{2. university,beijing 100871,China 1. department of Mathematics Tsing Hua University 30043 Hsinchu China 2. LMAM School of Mathematical Sciences Peking University 100871 Beijing China

In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

关键词： descriptor linear periodic system, pole assignment, proportional and derivative feedback, numerical method, periodic Schur decomposition.

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INVESTIGATION　ON　THE　WATER－SOLUBLE　YTTERBIUM　PORPHYRIN　PART　***，COMPOSITION　AND　STRUCTURE

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Chinese Chemical Letters 1995年第2期6卷 147-148页

作者： QianKun ZHUANO Xiao Xia GAO(department of Chemistry, peking university, {2., 100871) beijing Univ Dept Chem Beijing 100871 Peoples R China

Water-soluble ytterbium complex of tetra-p-sulfonatophenylporphyrin (H2.PPS)with the formulation Yb·TPPS·OH·2.im·3H2. (im=imidazole), stable in pH5 solution, has been synthesized and characterized by clemental analysis, IR and electronic absorption spectroscopy,Its structure is also proposed. The ytterbium atom exbibits a coordination number of seven with the ytterbium atom out of the prophyrin plane.

关键词： J

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Inclusive　Minimal　Surfacein　G2.n1

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北京大学学报(自然科学版) 1996年第3期 3-7页

作者： MO Miaohuan (department of Mathematics, peking university, {2., 100871)

刻划了从Ｒｉｅｍａｎｎ面到复Ｇｒａｓｓｍａｎｎ流形的具有拓扑度＞２ｎ（ｇ－１）或′阶有限的一切可兼极小浸入。

关键词：可兼极小浸入 Riemann面复Grassmann流形

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A new enzymatic method for determination of E. coli

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Chinese Chemical Letters 1999年第10期10卷 849-850页

作者： Yun Xiang CI Tian Le LI(department of Chemistry, peking university.{2.) beijing Univ Dept Chem Beijing 100871 Peoples R China

beta-Galactosidase, a kind of endoenzyme in E. coli cells. can be released by the pore-forming action of colicin El. and E. coli can be detected rapidly by enzymatic method.

关键词： E-coli colicin E1 enzymatic method

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The^(40)Ar/^(39)Ar age record of formation and uplift of the blueschists and eclogites in the western Tianshan Mountains

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Chinese Science Bulletin 2000年第11期45卷 1047-1052页

作者： GAO Jun, ZHANG Lifei & LIU Shengwei1. Institute of Geology, Chinese Academy of Geological Sciences, beijing 100037, China 2. department of Geology,{2., beijing 100871, Chin Institute of Geology Chinese Academy of Geological Sciences Beijing China department of Geology Peking University Beijing China

The 40Ar/39Ar ages indicate that the eclogite facies rocks of the Hasiate slice in the western Tianshan Mountains were formed at the early stage of Devonian （401 Ma） and had been uplifted to the greenschist facies t...

The sup>40/sup>Ar/sup>39/sup>Ar ages indicate that the eclogite facies rocks of the Hasiate slice in the western Tianshan Mountains were formed at the early stage of Devonian （401 Ma） and had been uplifted to the greenschist facies tectonic level in the middle stage of Devonian （381 Ma）. The formation and uplift of the blueschists of the Akesayi slice are constrained to the late stage of Devonian （370-364 Ma）. The different tectonic slices in the high-pressure metamorphic belt have experienced the different uplift history.

关键词： western Tianshan Mountains eclogite blueschist 40Ar/39Ar age.

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A numerical study for some efficient time-integration schemes using barotropic equations

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Acta Oceanologica Sinica 1989年第1期8卷 77-89页

作者： Han Wei and Zhang Yuling department of geophysics,{2., beijing, China Dept. of geophysics Peking Univ. Beijing China. China

Three kinds of methods, i. e., explicit, semi-implicit, and semi-implicit and semi-Lagrangian method, are tested in the time-integration of shallow-water equations on rotating sphere. Helpful results are available from experiments, especially about the accuracy and efficiency of different semi-implicit and semi-Lagrangian schemes.

关键词： time A numerical study for some efficient time-integration schemes using barotropic equations

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