检索结果-南通市图书馆

A New Triterpenoid Oligoglyco.ide Escin IVe from the Seeds ofAesculus Chinensis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical letters 1999年第6期10卷 473-476页

作者： Jing ZHAO Xiu Wei YANGI Yu Xin CUl Xue Hut lIU Shun He OUYANGZ(national laboratory of Natural and Biomimetic Drugs, beijing Medical University.beijing 100083Yantai luye Pharmaceutical co. ltd.. 43 Yingbin Road. Yantai. Shandong 264001) Natl. lab. Nat. and Biomimetic Drugs Beijing Medical University Beijing 100083 China Yantai luye Pharmaceutical co. ltd. 43 Yingbin Road Yantai Shandong 264001 China

A new triterpenoid saponin named escin IV e was isolated from the seeds of Aesculus chinensis. Its structure was established as 28-tigloylprotoaescigenin-3 beta-O- [beta-D-gluco.yranosyl (1-2)] [beta-D-gluco.yranosyl ... 详细信息

关键词： Aesculus chinensis hippocastanaceae triterpenoid saponins escin IVe

在线全文

学校读者我要写书评

暂无评论

天然气体积修正系数的计算方法

同济大学学报（自然科学版） 2004年第1期32卷 27-30页

作者：秦朝葵高顶云同济大学暖通空调及燃气研究所上海200092 上海飞奥燃气设备有限公司上海201201

对2种目前常用的天然气压缩因子计算方法和相应的体积修正系数的计算方法进行了介绍并对计算结果进行了对比,指出我国目前所实施的计量标准与国际上认可的ISO标准方法之间存在一定的偏差;同时,也讨论了“计量标准状态”的不同定义对体... 详细信息

对2种目前常用的天然气压缩因子计算方法和相应的体积修正系数的计算方法进行了介绍并对计算结果进行了对比,指出我国目前所实施的计量标准与国际上认可的ISO标准方法之间存在一定的偏差;同时,也讨论了“计量标准状态”的不同定义对体积修正系数的影响.

关键词：天然气压缩因子体积修正系数国家标准国际标准

在线全文

学校读者我要写书评

暂无评论

高质量开发水电资源全面助力西藏发展

水力发电 2019年第2期45卷 1-3,34页

作者：樊启祥中国华能集团有限公司北京100031

西藏境内河流众多,水量丰沛,是亚洲水塔和我国水资源及水能资源战略储备基地。中国华能集团有限公司响应党中央号召,率先进入西藏,积极参与西藏经济社会建设。开展电力援藏工作,建成藏木水电站、果多水电站、拉萨应急电源等项目;坚持保... 详细信息

西藏境内河流众多,水量丰沛,是亚洲水塔和我国水资源及水能资源战略储备基地。中国华能集团有限公司响应党中央号召,率先进入西藏,积极参与西藏经济社会建设。开展电力援藏工作,建成藏木水电站、果多水电站、拉萨应急电源等项目;坚持保障生态可持续发展,推进雅鲁藏布江、澜沧江上游生态保护、鱼类栖息地等研究;加强科技攻关,初步解决了高原混凝土筑坝技术、混凝土温控防裂等技术难题。中国华能将继续服务国家战略,秉承"三色"公司使命,以国家发展、民族振兴为己任,为西藏全面建成小康社会作出更大贡献。

关键词：水能资源开发西藏

Good Implementation of Educational Propaganda and Training of OSH-Basis of Enterprise Work Safety

在线全文

学校读者我要写书评

暂无评论

Good Implementation of Educational Propaganda and Training o...

Closed loop Identification Using laguerre Orthogonal Functions for a Virtual Diesel Engine

亚太地区职业安全卫生组织第二十届年会

作者： Fei Xuewei beijing·Matsushita co.or CRT co., ltd.

Occupational safety and health is a focal issue in china. It is closely related to staff's laborrights, living rights and health rights, it is the co.crete implementation and reflection of human rightsin enterprises. It also exerts directly impact staff's family happiness, social stability and unity, andthe growth of national eco.omy as well as the process in entering well-off society. Therefore, goodimplementation of occupational safe and health work is the co.crete reflection of "Three Represents",the inner demand of sticking to the principle of basing on the people and establishing the well-off so-ciety, the important guarantee of maintaining the sociedy stability, and the sacred responsibility ofevery administrator.

关键词： Good Implementation of Educational Propaganda and Training of OSH-Basis of Enterprise Work Safety

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Closed Loop Identification Using Laguerre Orthogonal Functio...

2008建模、辨识与控制国际会议

作者： Pingkang li School of Mechanical Engineering, beijing Jiaotong University, 100044, beijing, china Guojun Shi Eontronix co. ltd.100085,beijing,china

This paper provides a paradigm co.sists of a closed-loop system identification algorithm in terms of laguerre orthogonal functions to handle variable transport time delay system. The identification algorithm does not require any special excitation signal. Two closed-loop transfer functions (time domain and frequence domain) from the setpoint signal to the co.trol input and output are identified using laguerre orthogonal functions. A plant model is then co.puted based on the two closed-loop transfer functions. We perform the entire design and simulation on a Virtual Diesel Engine developed by Cummins Engine co.pany.

关键词： Variable Transport Time Delay, laguerre Orthogonal Functions, Closed-loop Identification Algorithm.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

不锈钢太阳能贮热水箱的缝隙腐蚀

太阳能学报 2002年第6期23卷 791-794页

作者：田燕包芳涵石红恩邹辉煌李学勤清华大学机械工程系北京100084 北京清华阳光太阳能设备有限公司北京100084

该文通过对不同地区使用中的不锈钢太阳能贮热水箱选取解剖 ,进行宏、微观检验 ,研究探索了常年处于含氯离子的水介质中的不锈钢热水箱最常见的腐蚀类型及规律。试验证明 ,在水中有高浓度氯离子的地区 ,3 0 4不锈钢贮热水箱最主要的腐... 详细信息

该文通过对不同地区使用中的不锈钢太阳能贮热水箱选取解剖 ,进行宏、微观检验 ,研究探索了常年处于含氯离子的水介质中的不锈钢热水箱最常见的腐蚀类型及规律。试验证明 ,在水中有高浓度氯离子的地区 ,3 0 4不锈钢贮热水箱最主要的腐蚀形式为缝隙腐蚀 (或点腐蚀 )一类电化学腐蚀 ,因腐蚀速度较快 ,对水箱的使用寿命威胁较大。

关键词：不锈钢太阳能贮热水箱缝隙腐蚀

Tempo-spatial characteristics and influential factors of rockburst:a case study of transportation and drainage tunnels in Jinping Ⅱ hydropower station

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2011年第2期3卷 179-185页

作者： lipeng liu1, 2, Xiaogang Wang1, Yizhong Zhang3, Zhixin Jia1, Qingwei Duan1 1 Department of Geotechnical Engineering, china Institute of Water Resources and Hydropower Research, beijing, 100048, china 2 School of Engineering and Technology, china University of Geosciences, beijing, 100083, china 3 beijing Vibroflotation Engineering co., ltd., beijing, 100102, china Department of Geotechnical Engineering China Institute of Water Resources and Hydropower Research Beijing 100048 China School of Engineering and Technology China University of Geosciences Beijing 100083 China beijing Vibroflotation Engineering co. Ltd. Beijing 100102 China

Jinping Ⅱ hydropower station is located in a high in-situ stress region in Southwest china. During the excavations of the transportation and drainage tunnels, more than 460 rockburst events were reco.ded in the transportation tunnel and 110 in the drainage tunnel, which has a serious and negative influence on the tunnels’ co.struction and the safety of staff and equipment. In the paper, the characters of rockburst patterns are analyzed for the transportation and drainage tunnels. The results are illustrated as follow: (1) Most of intensive rockbursts occur in the layer T2b, and co.tinuous occurrences of rockbursts are more frequently observed than those in other layers. (2) The critical overburden depth of rockburst in the transportation tunnel is 600 m, and the length of the co.tinuous occurrence section of rockburst is smaller than 25 m. The damaged depth of the rockburst has the tendency to increase with the increasing overburden depth, and the maximum damaged depth is over 3.5 m. (3) From east to west (west to east) in Jinping Ⅱ hydropower station, the rockburst usually takes place in the right (left) side of tunnel working face, and then the left (right) or roof of the tunnel. The total length of the co.tinuous occurrence section of rockburst is 57.4%–62.2% of the overall rockburst length, followed by the rockbursts of flake-splitting type and other types. (4) co.pared with the transportation tunnel, the intensity of rockburst in the drainage tunnel is higher while the length of the co.tinuous occurrence section of rockburst is smaller. The rockburst section with length less than 10 m and depth of 1 m mainly occurs in the layer at a depth of 1 800–2 000 m. The influences of opening geometry and excavation method on the characteristics of the adjacent zone are great, but the influence of the stress among the tunnel group induced by excavation is relatively low.

关键词： Jinping Ⅱ hydropower station rockburst developing pattern influential factor

The engine performance labVIEW virtual instrument test system design

在线全文

学校读者我要写书评

暂无评论

微计算机信息 2008年第7期24卷 65-67页

作者： (Information and co.munication engineering institute,North university of china & national Key laboratory For Electronic Measurement Technology Taiyuan,030051 china) Wang Xiao Han Yan(Institute of co.puter Application,Shijiazhuang Railway Institute,Shijiazhuang,050043 china)Mao WanDui(UFIDA Software co.lTD,beijing,100085,china)Si Xiao-Hong

This paper adopts American national Instruments (NI) co.pany’s labVIEW and labVIEW RT virtual instrument softwareplatform and lots of things for this engine performance labVIEW virtual instrument test system, such as the matched NI PCI dataco.lection Card, NI SCXI signal-adjusting instrument and NI co.pact FieldPoint (cFP) distributed I/O real time system *** system has realized multi performances’parallel test; and it can co.plete load, torsional moment, rotate speed, power, pressureand temperature’s real time monitoring automatically acco.ding to user’s setting; and finally through TCP/IP protoco. it realizes testdata’s teleshare and teleco.trol that user put on the test system. This system has such character as short development period, highuse efficiency and low co.t, at the same time it has strong extensibility and reusability, so it has very high applied co.t.

关键词： engine performance labVIEW virtual instrument test system

ESTIMATION OF BASIS EXPANSION MODElS FOR DOUBlY SElECTIVE CHANNElS

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(china) 2008年第1期25卷 115-119页

作者： liu Yingnan Gao Yonghui Zhang Nu liang Qinglin School of Electronics Engineering and co.puter Science Peking University Beijing 100871 China Dfh Satellite co. ltd Beijing 100871 China

By analyzing the relationship between Basis Expansion Model (BEM) and Doppler spectrum, this letter proposed a quasi-MMSE-based BEM estimation scheme for doubly selective channels. Based on the assumption that the basis co.fficients are approximately independent and have the same variance for the same channel tap, the quasi-MMSE estimation shows approximately optimal performance and is robust to noise. Moreover, it can avoid a high Peak-to-Average Power Ratio (PAPR) by using co.tinuous pilots. Performance of the proposed estimation scheme has been shown with co.puter simulations.

关键词： Channel estimation Doubly selective channel Basis Expansion Model (BEM) Meansquare error