检索结果-南通市图书馆

The species diversity of fusulinaceans and high-frequency sea-level changes in the carboniferous-Permian boundary section at Xikou, Zhen'an county,Shaanxi Province, china

引用

Science china Earth Sciences 2006年第7期49卷 673-683页

作者： ZHANG Haijun1. WANG Xunlian2, DING Lin1. XIA Guoying3.& WANG Lei2 1. {1. of Tibetan Plateau Research, chinese Academy of Sciences, Beijing 1.0085, china 2. Faculty of Earth Sciences and Mineral Resources, china University of Geosciences, Beijing 1.0083. china 3. Tianjin {1. of Geology and Mineral Resources, Tianjin 3.01.0, china 1. institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. Faculty of Earth Sciences and Mineral Resources China University of Geosciences Beijing 100083 China 3. Tianjin {1. of Geology and Mineral Resources Tianjin 300170 China

The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the carboniferous-Permian boundary section at Xikou, Zhen’an county, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an county, from the Late carboniferous to the Early Permian. There is a significant increase in species diversity around the carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive syst

关键词： fusulinaceans, species diversity, high-frequency cyclothem, sequence stratigraphy, sea-level changes, carboniferous-Permian boundary, Zhen'an, Shaanxi.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and verifying Web services driven by requirements:An ontology-based approach

引用

Science in china(Series F) 2006年第6期49卷 792-820页

作者： HOU Lishan1.3.JIN ZHi1.2 & WU Budan1.4 1. Academy of {1. and Systems Science, chinese Academy of Sciences, Beijing 1.0080, china 2. {3. of computing Technology, chinese Academy of Sciences, Beijing 1.0080, china 3. {3. of Software, chinese Academy of Sciences, Beijing 1.0080, china 4. Graduate University of chinese Academy of Sciences, Beijing 1.0049, china 1. Academy of mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China 3. {1. of Software Chinese Academy of Sciences Beijing 100080 China 2. institute of{1.omputing Technology Chinese Academy of Sciences Bejing 100080 China 4. Graduate University of chinese Academy of Sciences Beijing 100049 China

Automatic discovery and composition of Web services is an important research area in Web service technology, in which the specification of Web services is a key issue. This paper presents a Web service capability description framework based on the environment ontology. This framework depicts Web services capability in two aspects： the operable environment and the environment changes resulting from behaviors of the Web service. On the basis of the framework, a requirement-driven Web service composition model has been constructed. This paper brings forward the formalization of Web service interactions with π calculus. And an automatic mechanism converting conceptual capability description to the formal process expression has been built. This kind of formal specification assists in verifying whether the composite Web service model matches the requirement.

关键词： Web service environment ontology automatic composition π calculus formal verification.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deformation in the Three Gorges Reservoir after the first impoundment determined by GPS measurements

引用

Progress in Natural Science:Materials International 2005年第6期15卷 515-522页

作者： DU Ruilin 1.2 , QIAO Xuejun 1.2 *, WANG Qi 1.2 , XING canfei 1.2 and YOU Xinzhao 1.{1.(1. institute of Seismology, cEA, Wuhan 4{1.071. china 2. Laboratory of crustal Movement and Earth Observation, Wuhan 4{1.071. china {1. center for Analysis and Prediction, cEA, Beijing 1.00{1., china) institute of Seismology CEA Wuhan 430071 China Laboratory of crustal Movement and Earth Observation Wuhan 430071 China center for Analysis and Prediction CEA Beijing 100036 China

A 6-year long GPS observation (1.98—2003. indicates that{1.rustal deformation in the Three Gorges area is less active at a marginally measurable rate of 0—5 mm/a relative to stable South{1.hina block. However, the impounding water in June 2003.has induced transient displacement at the Three Gorges dam and the emerging reservoir. GPS measurements after the first stage of water filling of the reservoir demonstrate that vertical subsidence{1.lose by Yangtze River is about 1.—40 mm, and the horizontal displacement is less than 5—1. mm. The maximum subsidence induced by the impoundment is located in the segment of the reservoir from Maoping to Xiangxi. The water loading-induced deformation diminishes rapidly with the distance from banks of the reservoir. The overall pattern of transient deformation is{1.onsistent with the simulation result of Farrell, and is attributed to the elastic response of upper lithosphere{1.rust to overlying water reservoir.

关键词： Three Gorges GPS impoundment deformation.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Planar cubic hybrid hyperbolic polynomial curve and its shape classification

引用

Progress in Natural Science:Materials International 2004年第1期14卷 42-47页

作者： WANG Guozhao 1.2 * and YANG Qinmin 1.2 (1. institute of{1.omputer Graphics and Image Processing, 2. Department of mathematics, Zhejiang University, Hangzhou 3.0027,{1.hina) Zhejiang Univ Inst Comp Graph & Image Proc Hangzhou 310027 Peoples R China Zhejiang Univ Dept Math Hangzhou 310027 Peoples R China

The planar cubic hybrid hyperbolic polynomial curves and cubic H Bézier curves are presented. The conditions leading to inflection points and singularities (cusps and loops) are investigated and the shape of these curves is classified. The conclusions enable us to detect inflection points and singularities and get an idea of how to preserve the fair shape when designing such curves.

关键词： hybrid hyperbolic polynomial curve H-Bézier curve shape classification inflection points singularities

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Main chemical ingredients of the celadon glaze from Qingliangsi kiln and Zhanggongxiang kiln

引用

Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 487-495页

作者： ZHAO Weijuan1. LU Xiaoke1. LI Guoxia1. GUO Min1. XIE Jianzhong1. GAO Zhengyao1. SUN Xinmin2, GUO Musen2, cHENG Huansheng{1.& ZHANG Bin{1.1. Faculty of Physical Engineering, Zhengzhou University, Zhengzhou 450052, china 2. Research institute of cultural Relic and Archaeology, Henan Province, Zhengzhou 450004, china {1. Research institute of Modern Physics, Fudan University, Shanghai 2004{1., china 1. Faculty of Physical Engineering Zhengzhou University Zhengzhou 450052 China 2. Research institute of{1.ultural Relic and Archaeology Henan Province Zhengzhou 450004 China 3. Research {1. of Modern Physics Fudan University Shanghai 200433 China

The proton induced X-ray emission (PIXE) is used to determine the chemical ingredients of seven main elements in the samples of Ru Guan porcelain glazes and Ru civil porcelain from Qingliangsi kiln in Baofeng county and the samples of celadon glaze from Zhanggongxiang kiln in Ruzhou city. The PIXE data are then analyzed by scatter analysis and fuzzy cluster method for determining their classification and provenance. The results show that there are obvious differences between the ingredients of glaze material of Ru Guan porcelain and Ru civil porcelain from Qingliangsi kiln, of which the former ingredients are stable and its source is localized, and that the sources and ingredients of the glaze of Ru Guan porcelain and those of celadon glaze from Zhanggongxiang kiln are not wholly the same, of which the latter sources are much scattering.

关键词： Zhanggongxiang kiln, Qingliangsi kiln, the source of raw material, the proton induced X-ray emission.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A predict-correct projection method for monotone variant variational inequalities

引用

chinese Science Bulletin 1998年第15期43卷 1264-1267页

作者： HAN Qiaoming 1.and HE Bingsheng 2 1. institute of Applied {1., chinese Academy of Sciences, Beijing 1.0080, china 2. Department of {1., Nanjing University, Nanjing 21.093. china institute of Applied {1. Chinese Academy of Sciences Beijing China Department of mathematics Nanjing University Nanjing China

A predict_correct projection method is presented for solving monotone variant variational inequalities, which could exploit the advantages and overcome the difficulties of both explicit and implicit projection methods.

关键词： variant variational inequality explicit projection method implicit projection method predict_correct projection method.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reconstruction of precipitation variation from tree rings in recent 1.00 years in Delingha, Qinghai

引用

Science china Earth Sciences 2005年第7期48卷 939-949页

作者： SHAO Xuemei1. HUANG Lei1. LIU Hongbin2, LIANG Eryuan1. FANG Xiuqi3.& WANG Lili1.1. {1. of Geographic Sciences and Natural Resources Research, chinese Academy of Sciences, Beijing 1.01.1. china 2. National climate center, Beijing 1.0081. china 3. Beijing Normal University, Beijing 1.0875, china institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing 100101 China National climate center Beijing 100081 China Beijing Normal University Beijing 100875 China

Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1.00 years was re- constructed for Delingha. The reconstruction can capture 63.1. of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD1.20—1.3. and 1.3.—2001. whereas dry intervals in 1.29—1.1. and 1.3.—1.41. In ad- dition, the magnitude in precipitation variation was lower before 1.3. with about 1. mm, but it increased to 3. mm during the period of 1.3. to 1.50. After 1.50, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1.90s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1.00-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 21.t century.

关键词： northeastern part of the Qaidam Basin tree-ring width series of Qilian juniper precipitation reconstruction in 1.00 years.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal reactions for the synthesis of superheavy nucleus ^(270)Hs

引用

Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 641-648页

作者： LIU Zuhua1.3.& BAO Jingdong1.2 1. Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 1.0875,{1.hina 2. Physics Department, Beijing Normal University, Beijing 1.0875,{1.hina 3.{1.hina {3. of Atomic Energy, Beijing 1.241.0}{1.hina Key Laboratory of Beam Technology Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China Physics Department Beijing Normal University Beijing 100875 China china institute of Atomic Energy Beijing 102413 China

The superheavy nucleus 270Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 248cm(26Mg,4n)270Hs, 244Pu(3.Si,4n)270Hs, 23.U(3.S,4n)270Hs and 226Ra(48ca,4n)270Hs using a two-parameter Smoluchowski equation. It is found from our results that 226Ra(48ca,4n)270Hs and 23.U(3.S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

关键词： diffused fusion barrier,Smoluchowski equation,superheavy nuclei.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new DNA algorithm to solve graph coloring problem

引用

Progress in Natural Science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1. Li Yin2, Meng Ya3.and Meng Dazhi2(1. National Laboratory of Pattern Recognition,{1. of Automation, chinese Academy of Sciences, Beijing 1.0080, china 2. college of Applied Sciences, Beijing University of Technology, Beijing 1.0022, china 3. School of Science, Beijing {1. of Technology, Beijing 1.0081. china) National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China college of Applied Sciences Beijing University of Technology Beijing 100022 China School of Science Beijing Institute of Technology Beijing 100081 China

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some NP-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6R DNA encoding molecules if the number of regions in a graph is R).

关键词： DNA computing NP-hard problem graph coloring problem.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Distribution of molluscan remains in the sediment of the chukchi Sea and its vicinity, the Arctic

引用

Acta Oceanologica Sinica 2003年第4期22卷 607-619页

作者： Gao Aiguo 1.2, Xu Fengshan3. Sun Haiqing 1.2, Li Lon1.1. First {1. of Oceanography, State Oceanic Administration, Qingdao 266061.china. 2. Key Laboratory of Marine Sedimentology and Environmental Geology, State Oceanic Administration, Qingdao 266061.china 3. {1. of Oceanology, chinese Academy of Sciences, Qingdao 266071.china State Ocean Adm Inst Oceanog 1 Qingdao 266061 Peoples R China State Ocean Adm Key Lab Marine Sedimentol & Environm Geol Qingdao 266061 Peoples R China chinese Acad Sci Inst Oceanol Qingdao 266071 Peoples R China

The result of an analysis of mollusca remains collected from the chukchi Sea, Beaufort Sea and Bering Sea in the First chinese National Arctic Research Expedition, from July to September, 1.99 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, ***, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyrna fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, cyclocardia crebricostata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e., Nuculana pernula, N. radiata, Nucula bellotii, Macoma calcarea, M. moesta alaskana, Macoma sp. and Trichotropis coronata. Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

关键词： chukchi Sea Beaufort Sea Bering Sea molluscan remains

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：