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Thresholds of geographic environmental elements in sediment yield of drainage basins

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Science china Earth sciences 2005年第2期48卷 230-240页

作者： CHEN Hao, ZHOU Jinxing, CAI Qiangguo, LU Zhongchen & LI Zhongyan institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101,{4. institute of Forestry Science, chinese academy of Forestry Science, beijing 100091,{4. Research Center for Eco-Environment sciences, chinese academy of sciences, beijing 100085,{4. Computing institute of Science and Engineering, North{4. Electric Power University, beijing 102206,{4. 1. institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. institute of Forestry Science Chinese Academy of Forestry Science 100091 Beijing China 3. Research Center for Eco-Environment sciences Chinese Academy of Sciences 100085 Beijing China 4. Computing institute of Science and Engineering North China Electric Power University 102206 Beijing China

Threshold of environmental elements in drainage basin sediment yield refers to, under effect of climate, underlying surface and human activity, a turning point of abrupt changes in drainage sediment yield related to environmental element characteristics. Previous studies on threshold of sediment yield of relevant drainage basins were mainly concentrated on impact of natural zones with a few researches on impact of other environmental elements. Particularly studies on compound environmental element threshold in drainage basin sediment yield remain blank today. Studies indicate that sediment yield in drainage basins is affected by compound interactions and complex actions. Based on single element analysis, the present paper gives quantitatively compound threshold of environmental elements affecting sediment yield of the drainage basin between Hekouzhen and Tongguan in the middle Yellow River by the method of multi-variant, polynomial formula regression analysis.

关键词： middle Yellow River, environmental element, sediment, sediment delivery mudule, threshold.

ON THE CENTRAL RELAXING SCHEMES I:SINGLE CONSERVATION LAWS

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Journal of Computational Mathematics 2000年第3期18卷 313-324页

作者： Hua-zhong Tang (LSEC, institute of Computational Mathematics and Scientific /Engineering Computing, academy of Mathematics and System sciences, chinese academy of sciences, {4., 100080, china) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

Presents a central relaxing scheme for scalar conservation laws. Details on the preliminary equations; Properties of the relaxed schemes; Conclusions.

关键词： hyperbolic conservation laws the relaxing scheme TVD cell entropy inequality

Yangtzedonta and the early evolution of shelled molluscs

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chinese Science Bulletin 2001年第24期46卷 2103-2106页

作者： QIAN YiNanjing institute of geology and Palaeontology, chinese academy of sciences, Nanjing 210008, china Nanjing institute of geology and Palaeontology Chinese Academy of Sciences Nanjing China

The holotype of Yangtzedonta Yu, 1985 and its type species, Y. primitiva Yu, 1985, is an incomplete specimen of Xianfengella prima He et Yang, 1982. Therefore, based on the principle of priority, the names Yangtzedonta and Y. primitiva Yu (1985) should be abandoned. The fact that ventral valve of Xianfengella is bilaterally symmetrical indicates that they are not the left valve of a bivalved mollusc, as originally proposed by Yu. At present, the oldest certain bivalve is Xianfengoconcha elliptica Zhang, which occurs in the Early Cambrian Qiongzhusi Stage in china. The oldest known rostroconch is Heraultipegma yunnanensis He et Yang, which first occurs in the third small shelly fossil assemblage zone of the Early Cambrian Meishucunian Stage. The oldest known monoplacophoran, Maikhanella pristinis (Jiang), first occurs in the first small shelly fossil assemblage zone (Meishucunian Stage). Evidence derived from analyses of shell morphology, mode of growth, histology, and stratigraphic occurrence suggests

关键词： Yangtzedonta bivalves Xianfengella brachiopods enig- matic fossil.

On the origin of movable metal-type technique

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chinese Science Bulletin 1998年第20期43卷 1681-1692页

作者： PAN Jixing institute for History of Science, chinese academy of sciences, beijing 100010, china institute for History of Science Chinese Academy of Sciences Beijing China

china is the birthplace of woodblock, copperplate and non metal_type printing, movable metal_type technique, as the product of combination of copperplate and non metal_type technique, also originated in china. However, the problem on the origin of metal_type has not well been solved for a long time. This paper proved that metal_type was cast and used for paper money printing in china since the early 12th century, copper_type and tin_type technique was further developed during the 13.h to 14.h centuries, on the basis of investigation of excavated findings, textual research and scientific judgment. Finally a comparative research of the early metal_type technique in china, Korea and Europe was briefly discussed. A lot of unearthed material evidence were provided here.

关键词： china origin copperplate copper_type tin_type Song_Jin Yuan Ming.

Cenozoic terrestrial palynological assemblages in the glacial erratics from the Grove Mountains, east Antarctica

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Progress in Natural Science:Materials International 2009年第7期19卷 851-859页

作者： Aimin Fang a, Xiaohan Liu b, Weiming Wang c, Feixin Huang b, Lianjun Yu a a institute of geology and Geophysics, chinese academy of sciences, beijing 10002.,{4. b institute of Tibet Plateau Research, chinese academy of sciences, beijing 10002.,{4. c Nanjing institute of geology and Palaeontology, chinese academy of Science, Nanjing 210008,{4. [a]institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029 China [b]Institute of Tibet Plateau Research Chinese Academy of Sciences Beijing 100029 China [c]Nanjing Institute of Geology and Palaeontology Chinese Academy of Science Nanjing 210008 China

Fossiliferous glacial erratics have been found in moraines of the Grove Mountains, east Antarctica since 1998 by chinese National Antarctic Research Expedition (CHNARE) teams. These erratics were derived from a suite of glaciogene strata hidden beneath the Antarctic Ice Sheet in the Lambert glacier drainage system, and thus provide a record of Cenozoic paleoenvironmental conditions and fossil biotas that are so far unknown from outcrops and drill cores in this region. By microfossil analysis, sparse Neogene spores and pollen grains are revealed, including: Toroisporis (Lygodiaceae), Granulatisporites (Pteridaceae?), Osmunda (Osmundaceae), Polypodiaceae, Magnastriatites (Parkeriaceae), Deltoidospora, Araucariaceae, Taxodiaceae, Podocarpus (Podocarpaceae), Dacrydium (Podocarpaceae), Pinus (Pinaceae), Keteleeria (Pinaceae), Picea (Pinaceae), Tsuga (Pinaceae), Chenopodiaceae, Artemisia (Asteraceae), Asteraceae, Gramineae, Fraxinoipollenites (Oleaceae), Oleoidearumpollenites (Oleaceae), Oleaceae, Operculumpollis, Nothofagidites (Nothofagus), Rhus, Quercus (Fagaceae), Juglans (Juglandaceae), Pterocarya (Juglandaceae), Liquidambar (Hamamelidaceae), Ulmus (Ulmaceae), Ulmoidepites (Ulmaceae), Tilia, Proteacidites (Proteaceae) and Tricolpopollenites; but without any marine diatoms. Most of the spores and pollen grains in the erratics are considered to originate from local sources except for some older exotic components that might be recycled from the basement sedimentary rocks by the ice sheet, so they are in situ sporo-palynological assemblages. Furthermore, since the source areas of the glaciogenic sedimentary rocks are assumed to be local or in the up glacier areas, the palynological assemblages in these erratics represent an inland terrestrial flora during a warmer period of the ice-sheet evolutionary history. The ages of these erratics are also discussed based on the occurrence of some diagnostic pollens such as the Artemisia, Chenopodiaceae and Nothofagus, which implies

关键词： East Antarctica Grove Mountains Glacial erratics Spores and pollen Neogene

THE L^2-NORM ERROR ESTIMATE OF NONCONFORMING FINITE ELEMENT METHOD FOR THE 2ND ORDER ELLIPTIC PROBLEM WITH THE LOWEST REGULARITY

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Journal of Computational Mathematics 2000年第3期18卷 277-282页

作者： Lie-heng Wang (LSEC, institute of Computational Mathematics and Scientific/Engineering Computing, academy of Mathematics and System sciences, chinese academy of sciences, {4., 100080, china) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

Presents the abstract L...-norm error estimate of nonconforming finite element method. Use of the Aubin Nitsche Lemma in estimating nonconforming finite element methods; Details on the equations.

关键词： L-2-norm error estimate nonconforming f.e.m. lowest regularity

Effect of internal bubbly flow on pipe vibrations

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Science china(Technological sciences) 2010年第2期53卷 423-428页

作者： ZHANG MingMing & XU JianZhong institute of Engineering Thermophysics, chinese academy of sciences, beijing 100190, china 1. institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China

This paper presents an experimental investigation on wall vibrations of a pipe due to injection of a uniform bubble cloud into the pipe flow. For different bubble void fractions and averaged bubble sizes, the vibrations were measured using accelerometers. To understand the underlying physics, the evolution of the vibration spectra along the streamwise direction was examined. Results showed that wall vibrations were greatly enhanced up to 25 dB, compared with no bubble case. The characteristics of the vibration were mainly dependent on void fraction. These vibrations were believed to be caused by two mechanisms: acoustic resonance and normal modes of the bubble cloud. The former, originating from the interaction between the first mode of the bubble cloud and the first acoustic mode of the pipe, persisted along the entire pipe to enhance the vibration over a broad band frequency range, while the later, due to the process of bubble formation, successively decayed in the streamwise direction.

关键词： pipe vibration bubbly flow acoustic resonance normal mode decay rate

The boundary of palaearctic and oriental realms in western china

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Progress in Natural Science:Materials International 2008年第7期18卷 833-841页

作者： Ling Chen a,b,c, Yanling Songd,*, Shufang Xu e a Northwest institute of Plateau Biology, chinese academy of sciences, Xining 810001, china b Graduate University of the chinese academy of sciences, {4. 100039, china c National Science Foundation of china, {4. 100085, china d institute of Zoology, chinese academy of sciences, {4. 100101, china e {4. {14. of Agriculture and Forestry sciences, {4. 100097, china Northwest institute of Plateau Biology Chinese Academy of Sciences Xining 810001 China Graduate University of the chinese academy of sciences Beijing 100039 China National Science Foundation of china Beijing 100085 China institute of Zoology Chinese Academy of Sciences Beijing 100101 China beijing academy of Agriculture and Forestry sciences Beijing 100097 China

In the world-wide zoogeographic division, there has been no consentaneous understanding about the delimitation between palaearctic and oriental realms in western china. In this study, we will discuss the division based on amphibian distribution in Shaanxi, Gansu, Sichuan, Yunnan, and Tibet according to species coefficient similarity between each zoogeographic province. The results show that the northern border lies from Qinling Mountains–Feng Xian (Shaanxi)–Debu (Gansu)–Aba (Sichuan)–Batang–Bomi (Tibet), to Linzhi districts, and the southern border is from Taibai–Feng Xian in Shaanxi–Wen Xian (Gansu)–Songpan–Kangding–Daocheng (Sichuan), to Zhongdian–Gongshan in Yunnan, and westward to Motuo and Bomi district in Tibet.

关键词： Amphibian Zoogeography Palaearctic Oriental Hengduan Mt.

Spectrophotometric determination of cationic surfactants by formation of ternary complexes with Fe(Ⅲ) and chrome azurol S

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chinese Journal of Chemistry 1996年第3期14卷 228-234页

作者： SONG, Ming LIANG, Shu-Quan institute of Chemistry, chinese academy of sciences, beijing 100080, china institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(Ⅲ) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(Ⅲ):chrome azurol S:cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×104.***-1 and a linear range of 0.1-6.0 umol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.

关键词： Cationic surfactant determination spectrophotometry ternary complex Fe(Ⅲ) chrome azurol S