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101.
102 samples of limestones,mudrocks shales and tillites from the Sinian in Kuluketage have been analyzed ,Four formations in the Sinian belong to glacial deposits in which the differences in δ^13C are distinct (-14.7‰- 4.2‰),Distinctly negative δ^13C excursions for three times support the viwe of three glacial deposits in this area suggested by previous authors,except for the durations of them ,δ^13C values are generally positive in the Beiyixi Formation of lower part of the Lower Sinian ,representing probably the rock records of a continental rift related to break-up of the Rodinian supercontinent,There are three times of distinct excursions of δ^13C curve in all strata,The first one is from positive values at the bottom to about -5‰ at the top of the Beiyixi Formation ,The second one,from 0‰-3‰ in the Arletonggou Formation of upper part of the Lower Sinian to -3.4‰---14.4‰ in the Teruiaiken Formation.The third one,from positive values in the Zhamoketi Formation of lower part of the Upper Sinian to negative values in glacial varves at the top of the Hankeerqiaoke Formation. 相似文献
102.
DONGWei LIUJianhui PANYuerong 《科学通报(英文版)》2003,48(5):485-491
The Yuanmou Basin of Yunnan Province is a hotspot for the research of early homind evolution and its environmental background.During the implementation of the Program“Research of the Origin and Evolution of Early Man and Its Environmental Baqckground” from 1998 to 2001,a huge quantity of hominoid and mammal fossils were collected.The present report systematically describes an Euprox robustus sp.nov.identified during the recent laboratory work on the collected material.Euprox is a group of earliest cervids with true antlers.The new species is the third one of the genus discovered in China.Judged by its morphologic characteristics,the new species feed on juicy and tender leaves of dicotyledon.It implies that the vegetation of its epoch in the Yuanmou Basin is a kind of southern subtropical evergreen forest and the climate is humid and temperate with evident seasonality.The latter is mostly influenced by the monsoon and secondly by the latitude. 相似文献
103.
Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period 总被引:7,自引:0,他引:7
ZHANGRenjian XUYongfu HANZhiwei 《科学通报(英文版)》2003,48(10):1002-1005
Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing. 相似文献
104.
Progress in the study of tectophysicochemistry 总被引:1,自引:0,他引:1
LǖGuxian 《科学通报(英文版)》2003,48(11):1069-1079
Tectophysicochemistry is a research area that deals with the interrelations between physical and chemical changes of crustal materials caused by tectonism. A given tectonic force may be resolved into two parts: homogeneous stress and differential stress. Homogeneous stress refers to isotopic pressure, which is superimposed on the original pressure and affects the equilibrium of various chemical reactions. It is also a factor that influences petrogenesis,metallogenesis and metamorphism. Differential stress is commonly produced when external forces act on a given solid body. It may cause deformation of crustal materials and generate various kinds of structural features. Tectophysicochemistry pays special attention to pressure, temperature and other physicochemical conditions produced or induced by tectonism and studies the influences of additional tectonic parameters on various chemical equilibria, so it gradually develops into an independent area of science. 相似文献
105.
利用各阵元和目标相对于一中心阵元的几何关系建立目标运动方程,坐标变换方程和声阵列测量方程,并以此建立了声阵列目标定位模型。在此基础上提出了基于扩展Kalman滤波算法的目标定位数据融合算法。通过地面目标和空中目标的计算机仿真表明,本算法能够有效地克服由于智能雷布阵的随机性给智能雷定位数据估计带来的困难,对声阵列定位数据也能进行较好的融合,对提高定位精度有一定效果。 相似文献
106.
A novel hyper-redundant manipulator named RT1 is designed and studied. The unique feature of RT1 is all degrees of freedom (DOF) are actuated with only one motor via special designed hinge bar universal joints. The mechanisms of RT1 are introduced in detail. Some experiments are carried out in order to test the movability and adaptability of the manipulator. RT1 is actuated by pulse string and acts discretely. The discrete working space of RT1 is described and the parameter optimization for kinematical redundancy resolution is studied also. The optimization criterion is altering the design parameter as little as possible during manipulator's motion from the initial position to the expected position. An optimization example is given that is realized with Matlab optimize tool-box. 相似文献
107.
The Lattice-Boltzmann method is an effective tool for solving fluid mechanics problems, but there isn’t still a good scheme
to determinate some parameters in Boltzmann equations. In this paper, a technique using evolutionary algorithm to automatically
model Boltzmann equations is introduced. Numerical simulation shows that the designed scheme is fast and efficient.
Biography: Chen Ju-hua ( 1963-), male, Associate professor, research direction: Lattice-Boltzmann method, evolutionary algorithm. 相似文献
108.
WANG Yi CHU Wuyang SU Yanjing GAO Kewei & QIAO Lijie Department of Materials Physics University of Science & Technology Beijing Beijing China 《科学通报(英文版)》2003,48(12):1203-1206
It is known that some types of ceramics, like Al2O3 and ZrO2, undergo stress corrosion cracking (SCC) or static fatigue fracture under static loading, ever in a rela-tively mild environment, such as moist atmosphere or water at room temperature, which leads to a time-dependent fracture[1—4]. For a transmission electron microscopy specimen of YBa2Cu3O7-x ceramics superconductor, SCC induced by residual stress can occur in an atmosphere with low moisture content[5]. For a lead zirconate ti… 相似文献
109.
Do multiple cycles of aeolian deposit-pedogenesis exist in the reticulate red clay sections in southern China? 总被引:4,自引:0,他引:4
HU Xuefeng CHENG Tianfan & WU Hexin Department of Environmental Science Engineering Shanghai Uni-versity Shanghai China Correspondence should be addressed to Hu Xuefeng 《科学通报(英文版)》2003,48(12):1251-1258
Since the Quaternary scientists successfully dis-closed the paleoclimatic significance of the loess-paleo- sol sequence in the Loess Plateau, Northwest China, the loess-paleosol sequence has become well-known terres-trial materials revealing the multiple cyclic changes of Quaternary climates. As a carrier of paleoenvironmental information, it could compare beauty with the deep ocean deposit[8]. In recent years, however, the researchers began to put their sights to southern China. They try t… 相似文献
110.
Analysis of cDNA sequence, protein structure and expression of parotid secretory protein in pig 总被引:1,自引:0,他引:1
YINHaifang FANBaoliang ZHAOZhihui LIUZhaoliang FEIJing LINing 《科学通报(英文版)》2003,48(13):1358-1363
Parotid secretory protein (PSP) secreted abundantly in saliva, whose function is related with the anti-bacterial effect. The PSP cDNA has been isolated from pig parotid glands by 3′ and 5′ rapid amplification of cDNA end (RACE), based on the conserved signal peptide region among the known mammalian PSP. The result of homologous comparison shows that pig PSP and human PSP shares the high identity at the level of the primary, secondary and tertiary protein structure. A search for functionally significant protein motifs revealed a unique amino acid sequence pattern consisting of the residues Leu-X(6)-Leu-X(6)-Leu-X(7)-Leu-X(6)-Leu-X(6)-Leu near the amino-terminal portion of the protein, which is important to its function. RT-PCR, Dot blot and Northern blot analysis demonstrated that PSP was strongly expressed in parotid glands, but not in other tissues. 相似文献