检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

热轧生产线的建模与分析

系统工程理论与实践 2002年第9期22卷 78-83页

作者：卓之兵陈文德梁启宏中国科学院数学与系统科学研究院北京100080 北京理工大学自动控制系北京100081

用扩展时间事件图与极大代数方法相结合对一类批量生产的制造系统建立了模型 ,并在加工时间和存储器数量固定的条件下 ,用这模型对系统生产周期进行了分析。

关键词：热轧生产线建模分析扩展时间事件图离散事件动态系统

Geochemical records of carbon in recent sediments of Erhai Lake, china: Implication of effects of the Himalayas uplift on global environmental changes

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1999年第S2期44卷 123-124页

作者： WAN Guojiang~1, BAI Zhanguo~(1,2., WANG Haoran~1 and HUANG Ronggui~1 1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, chinese academy of Sciences, Guiyang 550002.{2. 2. State Key Laboratory of Plant Nutrition Research of chinese Ministry of Agriculture, Institute of Soil and Fertilizer, chinese academy of Agricultural Sciences, beijing 100081,{2.

THE formation and uplift of the Himalayas and the Tibetan Plateau may have been responsible for the past150 Ma global environmental changes, resulting in the development of a three-tiered landform in southernchina. The Yunnan-Guizhou Plateau, as the middle tier in eastern slope of the Himalayas, has beencomplex environmental unit with great altitude gradients and plateau landform characters. Both monsoonsfrom the Pacific and the Indian resulting in apparent environmental changes on variable time scales influence it. Environmental geochemical effect of low latitude-high altitude could be yielded, and well recorded in the geological bodies in this region. To build and verify a quantitative model of environmental evolution it is necessary to obtain high-resolution data of elemental cycles and mass equilibrium.

关键词： records sediments Erhai Lake Himalayas uplift global environmental changes.

在线全文

学校读者我要写书评

暂无评论

近红外偏振探测器校正方法

红外与毫米波学报 2018年第3期37卷 302-306页

作者：黄飞李范鸣王世勇陈超帅石永彪中国科学院红外探测与成像技术重点实验室上海200083 中国科学院大学北京100049 中国科学院上海技术物理研究所上海200083

近红外偏振探测器是近年来一种新的探测器结构,它将光栅附在了焦平面探测器的表面.为了解决光栅透射率和角度不均匀对线偏振度测量的影响,采用了一种新的线偏振度求解方法.该方法对光栅透射率和光栅角度进行了校正,消除了光栅透射率和... 详细信息

近红外偏振探测器是近年来一种新的探测器结构,它将光栅附在了焦平面探测器的表面.为了解决光栅透射率和角度不均匀对线偏振度测量的影响,采用了一种新的线偏振度求解方法.该方法对光栅透射率和光栅角度进行了校正,消除了光栅透射率和光栅角度不均匀性对线偏振度测量的影响,理论上表明了红外偏振成像质量与光栅透射率和光栅角度无关.实验结果显示,在使用黑体作为标定光源和不考虑偏振像元之间串扰的情况下,采用原有的计算方法得到的结果是真实值的14%~2.%,透射率校正后的结果是真实值的80%~12.%,透射率和角度校正后的结果是真实值的96%~104%.

关键词：红外偏振透射率校正角度校正线偏振度

Mass Extinction——A Fundamental Indicator for Major Natural Divisions of Geological History

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1988年第1期1卷 1-12页

作者： Xu Daoyi Zhang Qinwen Sun Yiyin Institute of Geology, State Seismological Bureau, beijing Institute of Geology, chinese {2. of Geological Sciences, beijing Institute of Geology, Academia Sinica, beijing Institute of Geology State Seismological Bureau Beijing China

In the Phanerozoic, there are three major geological boundaries: Precambrian/***/Triassic and Cretaceous/Tertiary. Studies of these boundaries in china and over the world stronglysuggest that they have the following similar features: mass extinctions of many taxa, positive anomalies ofplatinum-group metals, and abrupt changes of stable isotopes (δ13.). It is quite probable that these were theconsequences of some rare catastrophic events of extraterrestrial origin. Hence, the three above-mentionedmass extinction events may be regarded as key indicators for the division of the geological history of thePhanerozoic.

关键词： Mass Extinction A Fundamental Indicator for Major Natural Divisions of Geological History

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

土壤侵蚀与水土保持科学重点研究领域与问题

水土保持学报 2004年第1期18卷 1-6,26页

作者：冷疏影冯仁国李锐刘宝元郑粉莉刘国彬王占礼杨勤科傅伯杰宋长青国家自然科学基金委员会中国科学院资源环境科学与技术局中国科学院水利部水土保持研究所北京师范大学

进入新世纪,我国土壤侵蚀与水土保持科学研究迎来了新的发展机遇和挑战。在分析我国土壤侵蚀与水土保持学科研究的社会需求、科学需求及其特殊性的基础上,指出了我国土壤侵蚀与水土保持科学研究中存在的主要问题,提出了该领域亟待解决... 详细信息

进入新世纪,我国土壤侵蚀与水土保持科学研究迎来了新的发展机遇和挑战。在分析我国土壤侵蚀与水土保持学科研究的社会需求、科学需求及其特殊性的基础上,指出了我国土壤侵蚀与水土保持科学研究中存在的主要问题,提出了该领域亟待解决的前沿科学问题,如土壤侵蚀过程与机理,土壤侵蚀预报模型,水土保持措施防蚀机理及其适用性,流域生态过程和水土保持措施配置,大尺度土壤侵蚀与水土保持的格局及其变化规律,土壤侵蚀与水土保持环境效应评价,土壤侵蚀研究新技术与方法等。

关键词：土壤侵蚀水土保持防蚀机理适用性流域生态过程

EFFECT OF SLOW NEUTRON IRRADIATION ON SUPERCONDUCTIVE FILM

在线全文

学校读者我要写书评

暂无评论

低温物理学报 1993年第5期 398-404页

作者： Shi Zhixiang Jin Jirong Zhang Yitong Jin Xin Yao XixianDepartment of physics, National Lab. of Solid State MicrostructuresNanjin University, Nanjing 2.0008Changan Wang, Ruilan Wang, Hongchen Li Institute of physics, {2. {3. of Science, beijing 100080

Irradiation effect by slow neutrons at a low fluence of about 108n/cm2.on YBCO and GB-CO films was reported in this paper. It was experimentally shown that appropriate slow meutron irradiation would increase the critical current densities Jcm at higher temperature (78K) and have almost no effect on Jcm at lower temperature (57K). Peak effect deduced by appropriate irradiation was observed in the field dependence of Jcm and volume flux pinning force density Fp at 78K. Based on mechanisms of slow-neutron irradiation , some discussions were made.

关键词： EFFECT OF SLOW NEUTRON IRRADIATION ON SUPERCONDUCTIVE FILM 低温物理学报 high than

木聚糖酶分子结构与重要酶学性质关系的研究进展

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

生物工程学报 2005年第1期21卷 6-11页

作者：杨浩萌姚斌范云六中国农业科学院饲料研究所北京100081 中国农业科学院生物技术研究所北京100081

木聚糖是一种多聚五碳糖 ,是植物细胞中主要的半纤维素成分。木聚糖酶是可将木聚糖降解成低聚木糖和木糖的水解酶 ,它在饲料、造纸、食品、能源工业和环境科学上有着广阔的应用前景。随着分子生物学、结构生物学的发展及蛋白质工程的应... 详细信息

木聚糖是一种多聚五碳糖 ,是植物细胞中主要的半纤维素成分。木聚糖酶是可将木聚糖降解成低聚木糖和木糖的水解酶 ,它在饲料、造纸、食品、能源工业和环境科学上有着广阔的应用前景。随着分子生物学、结构生物学的发展及蛋白质工程的应用 ,对木聚糖酶结构和功能的研究不断深入。这里重点阐述与酶的活性、热稳定性、作用pH、等电点、底物亲和性及催化效率等重要性质相关的分子结构研究进展 ,讨论了其进一步的研究发展方向。研究木聚糖酶结构与功能的关系 ,对进一步加深木聚糖酶作用机制的了解、指导木聚糖酶的分子改良有重要意义。

关键词：木聚糖酶结构与功能催化残基热稳定性 pH性质底物亲和性

Adult congenital diaphragmatic hernia of the liver: a rare case report

在线全文

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2010年第2期53卷 204-206页

作者： LIU LiGuo1,2.XU YiYao1,MAO YiLei1,SANG XinTing1,YANG ZhiYing1,LU Xin1,ZHONG ShouXian1 & HUANG JieFu1 1 Department of Liver Surgery,Peking Union Medical College Hospital,beijing 10073.,{2. 2.Department of Abdominal Surgery,Cancer Institute and Hospital,chinese {3. of Medical Science and Peking Union Medical College,beijing 10002.,{2.. Department of Liver Surgery Peking Union Medical College Hospital Beijing China Department of Abdominal Surgery Cancer Institute and Hospital Chinese Academy of Medical Science and Peking Union Medical College Beijing China

Congenital diaphragmatic hernia (CDH), which mainly occurs in the newborn or in childhood with severe respiratory distress and high mortality, is rarely found in adult, especially for those uncommon right CDH [1–4]. ... 详细信息

关键词： case In Adult congenital diaphragmatic hernia of the liver a rare case report

Novel synergic combinatorial photoelectrochemical technology for degradation of trace of 2.chlorophenol in drinking water

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2003年第8期48卷 751-757页

作者： SONG Qiang & QU Jiuhui State Key Lab. of Environmental Aquatic Chemistry, Research Center for Eco-environmental Science, chinese academy of Sciences, {2. 100085,{3. Correspondence should be addressed to Qu Jiuhui (e-mail: jhqu@ ***) State Key Lab. of Environmental Aquatic Chemistry Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing 100085 China

A novel combinatorial photoelectrochemical (CPE) technology with combination of ultraviolet (UV)- photolysis and direct current (DC) electrolysis is studied and discussed for drinking water purification. In the self-made compositive photo-electrolysis incorporate reactor, removal rate of the 2.chlorophenol as model environmental pollutants has been investigated experimentally in terms of applied voltage, pH value, flow velocity, temperature, and aeration conditions. A primary analysis of the combinatorial photo-electric synergic effect on the degradation of organic pollut-ants has been carried out. It is found that the best perform-ance of CPE oxidation is achieved by the following condi-tions: DC voltage of 5.0 V combined with UV-2.4-raidation, near neutral of pH 8 with aeration of pure oxygen. The in-fluences of circular velocity, temperature, and initial concen-tration of the pollutant are minor. Under the optimal condi-tions, removal ratio of 2.CP is higher than 50% in 3. min, and 100% removal ratio of 2.CP (5 10-6) can be reached and TOC removal ratio reached above 90% in 2.5 h. Com-plete mineralization is achieved eventually. It shows in our investigation that under the studied conditions the synergic effect of UV photolysis and DC electrolysis on the degrada-tion of the model pollutant is remarkable and validated, which may be derived from the coexistence of mutual com-plementary mechanisms of photoelectrochemical action, and the radicals chain reactions resulted from photo activation and electrolysis excitation in the process of CPE oxidation.

关键词： 2.氯酚饮用水处理组合光电化学技术 CPE 紫外线