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Variations of δ^(18)O in precipitation from the Muztagata Glacier, East Pamirs

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Science china Earth sciences 2006年第1期49卷 36-42页

作者： LI Zhen1, YAO Tandong1,2, TIAN Lide1,2, XU Baiqing1,2 & Wu Guangjian2 1. Key Laboratory of Cryosphere and Environment, Jointly Established by Cold and Arid Regions Environmental and Engi-neering Research institute and institute of Tibetan Plateau Research, chinese academy of sciences and chinese academy of Meteorological sciences, china Meteorological Administration, CAS, Lanzhou 730000, china 2. Laboratory of Environment and process on Tibetan Plateau, institute of Tibetan Plateau Research, chinese academy of sciences, beijing 100085, china Key Laboratory of Cryosphere and Environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou China Laboratory of Environment and process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of2002 and 2003 collected precipitation samples and measured their oxygen isotopes. The δ^(18)O inprecipitation displays a wide range, varying from -17.40per thousand to +1.33per thousand inJune—September 2002 and from -22.31per thousand to +4.59per thousand in May—August 2003. Theδ^(18)O in precipitation correlates with the initial temperature of precipitation during theobserving periods. The positive correlation between δ^(18)O and temperature suggests that δ^(18)Ocan be used as an indicator of temperature in this region. The δ^(18)O values in fresh-snow samplescollected from two snow events at different elevations on the Muztagata Glacier show a strong''altitude effect'', with a ratio of nearly -0.40per thousand per 100 m from 5500 m to 7450 m.

关键词： Muztagata, δ18O, temperature, altitude effect.

The Real-gas Effect in Single-bubble Sonoluminescence

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Communications in Nonlinear Science and Numerical Simulation 1999年第1期4卷 29-34页

作者： Li YUAN (LSEC, institute of Computational Mathematics and Scientific-engineering Computing, chinese academy of sciences, beijing 100080, china) Wei WEI (Center for Nonlinear sciences, University of Science and Technology of china, Hefei 230026,china) LSEC Inst. Compl. Math./Sci.-Eng. Comp. Chinese Academy of Sciences Beijing 100080 China Center for Nonlinear sciences Univ. of Sci. and Technol. of China Hefei 230026 China Department of Physics Chinese University of Hong Kong Shatin Hong Kong

The full set of hydrodynamic equations governing the oscillation of a bubble is solved numerically by using a modified equation of state with ionization. We show that the hydro-thermal process in the form of compression waves and low-level ionization are dominant inside a sonoluminescing bubble for a wide range of driving pressure. The resulting thermal bremsstrahlung radiation has pulse heights and widths that agree with experimental data for cases considered in this paper.

关键词： single-bubble sonoluminescence ionization bremsstrahlung

ON COMPLEX DYNAMIC CONTROL SYSTEMS

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Journal of Systems Science & Complexity 2003年第3期16卷 350-357页

作者： CHENG Daizhan (institute of Systems Science, chinese academy of sciences, beijing 100080, china) institute of Systems Science Chinese Academy of Sciences 北京 100080

This paper presents some recent works on the control of dynamic systems,which have certain complex properties caused by singularity of the nonlinear structures,structure^varyings, or evolution process etc. First, we consider the structure singularity of nonlinear control systems. It was revealed that the focus of researches on nonlinear control theory is shifting from regular systems to singular systems. The singularity of nonlinear systems causes certain complexity. Secondly, the switched systems are considered. For such systems the complexity is caused by the structure varying. We show that the switched systems have significant characteristics of complex systems. Finally, we investigate the evolution systems. The evolution structure makes complexity, and itself is a proper model for complex systems.

关键词： relative degree byrnes-isidori normal form center manifold switchedsystems evolution system

THEORY OF NONFLUIDIZED GAS SOLIDS FLOW AND ITS APPLICATION

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Particuology 2005年第Z1期 27-39+4页

作者： Hongzhong Li Multi-Phase Reaction Laboratory, institute of process engineering, chinese academy of sciences, beijing 100080, P. R. china

A theory of nonfluidized gas-solids flow, which combines the theory of multiphase flow with the mechanics of particulate media, was proposed on the basis of understanding that the particles contact each other, solids and gas are in movement, and the drag force on the particles caused by interstitial gas flow is similar to gravity force having the property of mass force. Then this theory was verified by experiments on vertical and inclined moving beds, and was applied to calculation and design of equipment and devices with moving beds, such as pneumatic moving bed transport, dipleg, V-value, L-valve, orifice flow, and arching prevention. It can be used to guide the design and operation of moving beds and fixed beds.

关键词： theory nonfluidized gas-solids flow moving bed multiphase flow particulate material mechanics

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2, LI Anchun1, HU Ningjing2,3, FU Yongtao1& MA Zhibang4 1. institute of Oceanology, chinese academy of sciences, Qingdao 266071, china 2. Graduate School of the chinese academy of sciences, beijing 100039, china 3. institute of Soil Science, chinese academy of sciences, Nanjing 210008, china 4. institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, china institute of Oceanology Chinese Academy of Sciences Qingdao China Graduate School of the chinese academy of sciences Beijing China institute of Soil Science Chinese Academy of Sciences Nanjing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.

RHEOLOGICAL MODIFICATION OF EPOXY RESINS WITH NANO SILICA PREPARED BY THE SOL-GEL process

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chinese Journal of Polymer Science 1999年第3期17卷 253-257页

作者： Xia Wang Jiang Li Cheng-fen Long Yun-zhao Yu PCLCC institute of Chemistry, chinese academy of sciences, beijing 100080, china PCLCC is the Polymer Chemistry Laboratory, chinese academy of sciences and china Petro-Chemica Corporation 中科院化学所高分子化学联合开放实验室北京 100080 中科院化学所高分子化学联合开放实验室北京

Nano silica-modified epoxy resins were synthesized by the sol-gel process, The materials have the morphological structure of nano particales dispersed in the epoxy matrix. The dispersed phase formed a physical network in the resin and thus influenced the rheological behavior greatly. However, the nano silica did not show a significant influence on the mechanical properties of the cured resins.

关键词： epoxy resin nano silica mechanical properties rheology sol-gel process

High-temperature phases of pyrophyllite and their evolutionary characteristics

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chinese Science Bulletin 1997年第2期42卷 140-144页

作者： WANG Ling and ZHANG Zhenyu1. Changsha institute of Geotectonics, chinese academy of sciences, Changsha 410013, china 2. institute of Geology, chinese academy of sciences, beijing 100029, china Changsha institute of Ceotectonics Chinese Academy of Sciences Changsha China institute of Geology Chinese Academy of Sciences Beijing China

WITH the increase of heating temperature, phase of pyrophyllite will undergo a series of transformations. Former scholars have done some work in this respect; the temperature spans,however, were normally not more than 1150℃ and no relatively comprehensive results have been reported. Thus, the features of the phases from indoor temperature to melting point (1710℃±) for pyrophyllite and the entire evolutionary process of the phases are uncertain.

关键词： pyrophyllite high-temperature phase phase tranformation pyrophyllite anhydrite mullite cristobalite.

Follicular growth,differentiation and atresia

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chinese Science Bulletin 2003年第17期48卷 1786-1790页

作者： JIN Xuan & LIU Yixun State Key Laboratory of Reproductive Biololgy, institute of Zoology, chinese academy of sciences, beijing 100080, china State Key Laboratory of Reproductive Biololgy Institute of Zoology Chinese Academy of Sciences Beijing 100080 China

Only limited numbers of primordial follicles in mammalian ovary grow and differentiate to reach the stage of dominate follicles and ovulate. 99% of the follicles in the ovary undergo atresia at various stages of development. Regulation of follicular growth, development and atresia is a complex process and involves interactions between endocrine factors and intraovarian regulators. This review summa-rized:ⅰ) FSH may not be a survival factor in regulating slow-growing preantral follicles. Some locally produced growth factors, activin and orphan receptors might play a more important role at this stage. ⅱ) Estrogen, activin/ inhibin and follistatin coordinate with FSH to regulate and control follicle differentiation. ⅲ) There are two types of follicular atresia induced by apoptosis which originates from GC or oocyte, respectively. Early translation of tPA mRNA into tPA protein in oocyte may be associated with oocyte apoptosis.

关键词：哺乳动物原始卵泡卵泡生长粒状细胞细胞分化

A class of additive-accelerated means regression models for recurrent event data

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Science china Mathematics 2010年第12期53卷 3139-3151页

作者： LIU Li 1, MU XiaoYun 2 & SUN LiuQuan 2 1 School of Mathematics and Statistics, Wuhan University, Wuhan 430072, china 2.institute of Applied Mathematics, academy of Mathematics and Systems Science, chinese academy of sciences, beijing 100080, china School of Mathematics and Statistics Wuhan University Wuhan China institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China

In this article, we propose a class of additive-accelerated means regression models for analyzing recurrent event data. The class includes the proportional means model, the additive rates model, the accelerated failure time model, the accelerated rates model and the additive-accelerated rate model as special cases. The new model offers great flexibility in formulating the effects of covariates on the mean functions of counting processes while leaving the stochastic structure completely unspecified. For the inference on the model parameters, estimating equation approaches are derived and asymptotic properties of the proposed estimators are established. In addition, a technique is provided for model checking. The finite-sample behavior of the proposed methods is examined through Monte Carlo simulation studies, and an application to a bladder cancer study is illustrated.

关键词： additive-accelerated means model counting process marginal model model checking recurrent events