检索结果-南通市图书馆

Plus cupping degrees do not form an ideal

在线全文

学校读者我要写书评

暂无评论

Science in china(Series F) 2004年第5期47卷 635-654页

作者： LI Angsheng1.2.& ZHAO Yicheng1.1. Institute of Software,{1. academy of {2.,Beijing 1.0080,china 2. School of Information {2.,Beijing Normal University,Beijing 1.0871.china 1. Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. School of Information {1. Beijing Normal University 100871 Beijing China

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0 详细信息

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0

关键词： computably enumerable set Turing degree definability.

Principles and methods of quantitative analysis on b-axis disorder in 2.: 1.dioctahedral phyllosilicate

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1997年第22期42卷 1908-1912页

作者： WANG Ling and ZHANG Zhenyu1. Changsha Institute of Geotectonics, chinese {1. of {2., Changsha 41.01., china 2. Institute of Geology, chinese {1. of {2., Beijing 1.002., china Changsha Institute of Geotectonics Chinese Academy of Sciences Changsha China Institute of Geology Chinese Academy of Sciences Beijing China

IN XRD patterns of clay minerals, a phenomenon that strong peaks often have (00l) and(hkl) (k=3n) indices and show symmetric figures can be seen commonly, while a minorityof reflection peaks (hkl) (k≠3n) are comparat... 详细信息

关键词： b-axis disorder pyrophvllile 2 phyllosilicate clay minerals dioctahedral minerals orientating structure of hy-droxyls crystal structure analysis DTA-TG.

Current status and future of acid rain in china

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1997年第24期42卷 2076-2081页

作者： DING Guo’an, XU Xiaobing, FANG Xiumei, JIN Shaping, XU Xia, Tang Jie, LIU Qijun, WANG Shufeng and WANG Wenxing1. chinese {1. of {2. sciences, Beijing 1.0081. china 2. chinese {1. of Environment sciences, Beijing 1.001.2} china chinese {1. of {2. sciences Beijing 100081 China

As a part of the national key project of acid rain research, chemical element analysis of rainwater has been carried out based on observation of acid rain network in chinese {1.Administration over the years of 1.92.and 1.93. Samples of precipitation collected from eachacid rain station were taken according to the standard established by chinese {1.Administration. pH value was measured with pH meter (accuracy of 0. 01. made in

关键词： acid rain current status future.

Global convergence property of s-dependent GFR conjugate gradient method

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1998年第23期43卷 1959-1965页

作者： WANG Changyu 1.2.and ZHANG Yuzhong\+1.1. Institute of Operations Research in Qufu Normal University, Qufu 2.31.5, china 2. Institute of Applied Mathematics, chinese {2. of sciences, Beijing 1.0080, china Institute of Operations Research Qufu Normal University Qufu China Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.

关键词： steplength linear search global convergence conjugate gradient.

Variations of δ^(1.)O in precipitation from the Muztagata Glacier, East Pamirs

在线全文

学校读者我要写书评

暂无评论

Science china Earth {1. 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 {2. and chinese academy of meteorological {2., china meteorological Administration, CAS, Lanzhou 730000, china 2. Laboratory of Environment and Process on Tibetan Plateau, Institute of Tibetan Plateau Research, chinese academy of {2., Beijing 100085, china 1. 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 730000 China 2. Laboratory of Environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of2.02.and 2.03 collected precipitation samples and measured their oxygen isotopes. The δ^(1.)O inprecipitation displays a wide range, varying from -1..40per thousand to +1.33per thousand inJune—September 2.02.and from -2..31.er thousand to +4.59per thousand in May—August 2.03. Theδ^(1.)O in precipitation correlates with the initial temperature of precipitation during theobserving periods. The positive correlation between δ^(1.)O and temperature suggests that δ^(1.)Ocan be used as an indicator of temperature in this region. The δ^(1.)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 1.0 m from 5500 m to 7450 m.

关键词： Muztagata, δ1.O, temperature, altitude effect.

Y_CΩ_(2.)are easy terms

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1998年第20期43卷 1707-1709页

作者： ZHAO Xishun 1.and WANG Ju 2.1. Department of Mathematics, Nanjing University, Nanjing 2.0093, china 2. Institute of Software, chinese {2. of sciences, Beijing 1.0080, china Department of Mathematics Nanjing University Nanjing China Institute of Software Chinese Academy of Sciences Beijing China

For any natural number n≥1. Y CΩ 2. is an easy term; that is, for any λ term M, λβ+Y\-CΩ 2. =M is consistent, where Y C is Curry fixed point combinator, Ω 2. ≡ω 2. ω 2. and ω 2. ≡λ***...x (there are 2. occurrences of x after λx ). This result is a partial solution to Jacopini’s conjecture: Y CΩ n is an easy term for any natural number n≥2.

关键词： λβ-calculus Kuper’s theorem easy term.

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

在线全文

学校读者我要写书评

暂无评论

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. {1. of Mathematics and Systems Science, chinese {1. of sciences, Beijing 1.0080, china 2. Institute of Computing Technology, chinese {1. of sciences, Beijing 1.0080, china 3. Institute of Software, chinese {1. of sciences, Beijing 1.0080, china 4. Graduate University of chinese {1. of sciences, Beijing 1.0049, china 1. academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China 3. Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. Institute of Computing Technology Chinese Academy of Sciences Bejing 100080 China 4. Graduate University of chinese {1. of {2. 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.

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

在线全文

学校读者我要写书评

暂无评论

Science china Earth {1. 2006年第5期49卷 554-560页

作者： FAN Ke1.2.3 & WANG Huijun2.1. Nansen-Zhu International Research Center, Institute of Atmospheric Physics, chinese academy of {2., Beijing 1.002., china 2. Department of Atmospheric Science, Yunnan University, Kunming 650091. china 3. Graduate University of the chinese academy of {2., Beijing 1.0049, china 1. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric Science Yunnan University Kunming 650091 China 3. Graduate University of the chinese {1. of {2. Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Climatic and environmental changes over the last millennium recorded in the Malan ice core from the northern Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Science china Earth {1. 2006年第10期49卷 1079-1089页

作者： WANG Ninglian1.2. YAO Tandong2.1. PU Jianchen1. ZHANG Yongliang1.& SUN Weizhen1.1. Key Laboratory of Cryosphere and Environment, Cold and Arid Regions Environmental and Engineering Research Institute, chinese academy of {2., Lanzhou 730000, china 2. Institute of Tibetan Plateau Research, chinese academy of {2., Beijing 1.0085, china 1. Key Laboratory of Cryosphere and Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China 2. Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

In this paper, climatic and environmental changes were reconstructed since 1.2.A.D. based on the Malan ice core from Hol Xil, the northern Tibetan Plateau. The record of δ 1.O in the Malan ice core indicated that the warm-season air temperature variations displayed a general increase trend, the 2.th-century warming was within the range of natural climate variability, and the warmest century was the 1.th century while the warmest decade was the 1.1.s, over the entire study period. The “Medieval Warm Epoch” and “Little Ice Age” were also reflected by the ice core record. The dust ratio in the Malan ice core is a good proxy for dust event frequency. The 870-year record of the dust ratio showed that dust events occurred much frequently in the 1.th century. Comparing the variations of δ 1.O and the dust ratio, it is found that there was a strong negative correlation between them on the time scales of 1.1.1.2.years. By analyses of all the climatic records of ice cores and tree rings from the northern Tibetan Plateau, it was revealed that dust events were more frequent in the cold and dry periods than in the warm and wet periods.

关键词： the Tibetan Plateau, the Malan ice core, climate changes, dust event frequency.