检索结果-南通市图书馆

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第3期47卷 232-238页

作者： LIU Xiangwen1,2. YANG Guangming2. ZOU Huamin3. QU Jing1 & ZHAO Wenxia4 1. graduate {3., China {2. of {3., wuhan 43.074, China 2. Test Center, China {2. of {3., wuhan 43.074, China 3. Physics and Technology College, wuhan {2., wuhan 43.072. China 4. Test Center, Zhongshan {2., Guangzhou 5102.5, China China Univ Geosci Grad Sch Wuhan 430074 Peoples R China China Univ Geosci Test Ctr Wuhan 430074 Peoples R China wuhan Univ Phys & Technol Coll Wuhan 430072 Peoples R China Zhongshan Univ Test Ctr Guangzhou 510275 Peoples R China

Sakhaite specimens from an endogenous borate deposit in Hunan Province, China have been studied in detail by means of transmission electron microscopy (TEM). The selected area electron diffraction (SAED) patterns obtained with different crystal zone axes show that the crystal system is cubic, with a = 1.463.nm. The convergent beam electron diffraction (CBED) patterns indicate that the point group and space group of sakhaite is m3. and Fd3., respec-tively. The space group of synthetic sakhaite determined by Chichagov (1974) is F413.0} The possible reasons why the space groups of the natural and the synthetic sakhaites are different are discussed.

关键词： sakhaite, space group, convergent beam electron diffraction (CBED).

On the Symmetry Classes of Functions

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2005年第5期10卷 813-816页

作者： ZHU Ping~1,2. FAN Yun~3.1. school of Mathematics and Statistics, wuhan {2., wuhan 43.072. Hubei, China 2. school of Science, Beijing {2. of Posts and Telecommunications, Beijing 100876, China 3. school of Mathematics and Statistics, Huazhong Normal {2., wuhan 43.079, Hubei, China wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) Beijing university of Posts and Telecommunications School of Science Beijing China (GRID:grid.31880.32) Huazhong Normal university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.411407.7) (ISNI:***)

Let R be an integral domain of characteristic zero such that the corresponding group rings have block decompositions. We first prove that the submodule consisting of all the R-valued ξi-symmetric functions of several variables is a symmetry class, where ξi is any block character. Then we present a relationship among certain operators introduced for block character. Then we present a relationship among certain operators introduced for block characters. As a consequence, we obtain a decomposition of an arbitrary R-valued function of several variables. Finally, we describe the symmetry property of such summands and determine all the symmetry classes.

关键词： symmetry class strict symmetry class blockcharacter ξi-symmetric function block idempotent

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2. ZHAO Zhidan1,2. ZHANG Hongfei3. ZHANG Benren3.& CHEN Yuelong2.1. State Key Laboratory of Geological Processes and Mineral Resources, China {3. of geosciences, Beijing 100083. China 2. {2. of Earth Science and Mineral Resources, China {3. of geosciences, Beijing 100083. China 3. Faculty of Earth Sciences, China {3. of geosciences, wuhan 43.074, China 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China 2. school of Earth Science and Mineral Resources China University of Geosciences Beijing 100083 China 3. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.2.). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2.b-Zr/4-Y and Ti/100-Zr-YX3.tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143.Nd/^(144)Nd (0.512.55-0.512.78). Pb isotopes are in the rangeof ^(2.6)Pb/^(2.4)Pb (18.054-2..562., ^(2.7)Pb/^(2.4)Pb (15.53.-15.743. and ^(2.8)Pb/^(2.4)Pb(3..068-3..53.). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

COLLECTIVELY COMPACT COMPOSITION OPERATOR SEQUENCES BETWEEN BERGMAN AND HARDY SPACES

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2004年第2期24卷 206-212页

作者：王茂发刘培德 schoolofMathematicsandStatistics WuhanUniversityWuhan430072China

This paper studies the collective compactness of composition operator sequences between the Bergman and Hardy spaces. Some sufficient and necessary conditions involving the generalized Nevanlinna counting functions fo... 详细信息

关键词： Bergman space Hardy space composition operator collectively compact operator sequence

Prediction of Tumor Outcome Based on Gene Expression Data

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2004年第2期9卷 177-182页

作者： Liu Juan 1,2. Hitoshi Iba 3.1. school of Computer, wuhan {2., wuhan 43.072. Hubei, China 2. State Key Laboratory of Software Engineering, wuhan 43.072. Hubei, China 3. Department of Frontier Informatics, {2. of Tokyo, Tokyo 113.8656, Japan wuhan university School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) State Key Laboratory of Software Engineering Wuhan Hubei China (GRID:grid.49470.3e) university of Tokyo Department of Frontier Informatics Tokyo Japan (GRID:grid.26999.3d) (ISNI:***)

Gene expression microarray data can be used to classify tumor types. We proposed a new procedure to classify human tumor samples based on microarray gene expressions by using a hybrid supervised learning method called MOEA+WV (Multi-Objective Evolutionary Algorithm+Weighted Voting). MOEA is used to search for a relatively few subsets of informative genes from the high-dimensional gene space, and WV is used as a classification tool. This new method has been applied to predicate the subtypes of lymphoma and outcomes of medulloblastoma. The results are relatively accurate and meaningful compared to those from other methods. Key words bioinformatics - tumor classification - Pareto optimization - MOEA CLC number Q 786 - TP 181 Foundation item: Supported by the National Natural Science Foundation of China (603.1009), the Foundation of Young Scholars of Ministry of Education of China (150118) and Chenguang Project of wuhan City (2.112.009).Biography: Liu Juan (1970-), female, Associate Professor, Postdoctoral, research direction: bioinformatics, data mining, machine learning.

关键词： bioinformatics tumor classification Pareto optimization MOEA

Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第8期49卷 862-871页

作者： YANG Ruiyan1,2. MA Dongsheng2. BAO Zhengyu3. PAN Jiayong2. CAO Shuanglin2.& XIA Fei2.1. school of Mathematics and Physics, China university of {2.,{3., China 2. State Key Laboratory for Research of Mineral Deposits, Nanjing university, Nanjing 2.0093. China 3. Faculty of Earth Sciences, China university of {2.,{3., China 1. school of Mathematics and Physics China University of Geosciences Wuhan 430074 China 2. State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China 3. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2.0.4 m/a.

关键词： ore-forming fluid, numerical simulation, geothermal field, geofluid transport, Xikuangshan, antimony deposits.

Variation properties of ionospheric eclipse factor and ionospheric influence factor

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第6期15卷 573-576页

作者： ZHAO Chunmei 1,2.*, YUAN Yunbin1, OU Jikun1 and CHEN Jinping3.1. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, wuhan 43.077, China 2. {3. {2. of Chinese Academy of Sciences, Beijing 10003., China 3. Department of Precision Instrument and Mechanology, Tsinghua {3., Beijing 100084, China) Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China graduate school of Chinese Academy of Sciences Beijing 100039 China Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

关键词： GPS ionospheric eclipse factor ionospheric influence factor

The characteristics of arc beam shaping in hybrid plasma and laser deposition manufacturing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第2期49卷 238-247页

作者： ZHANG Hai’ou1, QIAN Yingping1,3. WANG Guilan1 & ZHENG Qiguang2.1. school of Material Science and Technology, Huazhong university of Science and Technology,{2., China 2. Institute of Laser Technology and Engineering, Huazhong university of Science and Technology,{2., China 3. Mechanical Engineering College, Hubei university of Technology, wuhan 43.068, China 1. school of Material Science and Technology Huazhong University of Science and Technology Wuhan 430074 China 3. Mechanical Engineering College Hubei University of Technology Wuhan 430068 China 2. Institute of Laser Technology and Engineering Huazhong University of Science and Technology Wuhan 430074 China

As a new direct metal prototyping technology,the hybrid plasma and laser deposition manufacturing (PLDM) is proposed in this paper. In order to figure out the characteristics of plasma arc beam and mould in the PLDM process of high temperature alloy, the high speed CCD camera is used to obtain the picture around the plasma arc. Afterwards the sketch of picture is clearly obtained. And the effect of laser parameter, such as average power, pulse width, pulse repetition frequency and the angle between laser beam and plasma arc beam on the plasma arc appearance, is studied experimentally. The results show that the modality of plasma arc beam is markedly influenced by laser beam. And the improvements of shape precision and surface state of the layer deposited by PLDM are confirmed.

关键词： plasma hybrid laser, direct deposition, plasma arc beam, molding character, high-temperature alloy.

The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan Province, China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2004年第9期47卷 846-864页

作者： TIAN Youping1,3. ZHANG Jie2. SONG Linhua1 & BAO Haosheng2.1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. Department of Geography, Nanjing {3., Nanjing 2.0093. China 3. school of Earth Sciences and Resources, China {3. of {3., Beijing 100083. China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Geography Nanjing University Nanjing 210093 China school of Earth Sciences and Resources China University of Geosciences Beijing 100083 China

Aerial algae on the surface of carbonate rocks at the Stone Forest, Shilin County, Yunnan Province, China, and their bioerosion were investigated in the field and studied in the laboratory in detail. Through the observation, identification and statistics of more than one hun- dred algal samples and rock samples with the optical microscopes (stereomicroscope, biological microscope) and the scanning electronic microscope (SEM), the relationships between erosional forms on the surface of the Stone Forest and algae and/or algal communities and the genetic mechanism for the formation of erosional forms were analyzed. It is suggested that aerial algae play an active role in bioerosive processes that may affect the formation of karst erosional forms. These effects include both direct and indirect ones. The direct effect is the initiative control (algal shape-controlling role) of algae on the formation of karst forms of various scales, mostly mi- cro-scale (3.) and minor-scale (10-3.10-1m) erosional forms. The algal shape-controlling roles can be divided into the algal individual shape-controlling role and the algal community shape-controlling role. The former mostly controls the formation of micro-scale erosional forms, while the latter mostly controls the formation of micro-scale and smaller minor-scale erosional forms. The indirect effect refers to the promoting role of algae in the formation of karst forms, which may affect the formation of karst forms of all types and scales. The bioerosion of algae accelerates the weathering process of the whole Stone Forest karst landforms.

关键词： aerial algae, bioerosion, the Stone Forest, Yunnan Province, China.