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Altered arbuscular mycorrhizal fungi communities favoring invasive weed Ageratina adenophora Sprengl competition over natives

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Altered arbuscular mycorrhizal fungi communities favoring in...

Addressing severe slope failure hazards along Sichuan-Tibet Highway in Southwestern china

第三届全国生物入侵大会

作者： Wen-qing Yu~(1,2),Li-li Zhang~3,Fang-hao Wan~1,Wan-xue Liu~(1*) 1 State key laboratory for Biology of Plant Diseases and Insect Pests,institute of Plant Protection, chinese academy of Agricultural sciences,beijing 100094 2 Heilongjiang academy of Land Reclamation sciences,Jiamusi,Heilongjiang,154007

To investigate the difference of Arbuscular mycorrhizal fungi(AMF) community between exotic weed Ageratina adenophora invaded soil and native weeds dominated soil,and to inspect the feedback of the different AMF community to competitive interaction of the exotic weed with native plants,we conducted field and glasshouse *** field experiments showed that the aboundance of Glomus geosporum,Acaulospora dilatata and Acaulosporafoveata in exotic *** dominated soil

关键词： AM symbiosis AMF Feedback to plants Competitive interactions Community diversity Exotic plant Mechanism of invasion Plant-plant interactions Plant-soil interactions

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Addressing severe slope failure hazards along Sichuan-Tibet ...

Local segment-shared protection based on source egress gateway selection for multi-domain optical mesh networks

中国科学院地质与地球物理研究所2003学术年会

作者： Shang Yanjun~1,Yue Zhongqi~2,Yang Zhifa~1,Wang Yangchun~3,and Liu Da’an~1 1.institute of Geology and Geophysics,chinese academy of sciences,beijing 100029,china, 2.Department of Civil Engineering,The University of Hong Kong,Hong Kong,china 3.institute of Mountain Hazards and Environment,chinese academy of sciences & Water Conservancy Ministry,Chengdu 610041,china

This paper presents the results of recent field investigations on the geological hazards along the Sichuan-Tibet Highway in Southwestern *** was found that one section of the highway has been facing severe problems in slope *** is the section between Linzhi and Basu and it has been the most dangerous part of the highway system to road users over the last fifty years. Based on the examination of structural geology,Quaternary geology,stratigraphy and petrography,this paper presents the classification,distribution and hazard levels of the slope failures along the highway section. The failures usually occurred in slopes comprising Quaternary glacial deposits,fluvio-lacustrine deposits and residual *** can be classified as landslides, mud-rock flows,grain flows on slopes and rock *** are caused by four main factors:a) intense active tectonic movements,b) on-going alpine canyon relief,c) heavy precipitation and d) irrational human *** paper further discusses the engineering measures adopted by the relevant organizations over the past fifty *** on the investigations,the paper summarizes some useful recommendations to effectively address and mitigate the severe slope failure hazard problem for safe operation of the highway and future railway systems.

关键词：

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Science china(Information sciences) 2011年第2期54卷 227-235页

作者： ZHANG ShengFeng1,3, PENG YunFeng1,2, DU Shu1, YANG XiaoLong1,2 & LONG KePing1,2 1Research Center for Optical Internet and Mobile Information Networks, University of Electronic Science and Technology of china, Chengdu 611731, china 2institute of Advanced Network Technology and New Serives (ANTS), University of Science and Technology beijing, beijing 100083, china 3Research Center for Optical Internet Networks, Chongqing University of Posts and Telecommunications, Chongqing 400065, china Research Center for Optical Internet and Mobile Information Networks University of Electronic Science and Technology of China Chengdu China Research Center for Optical Internet Networks Chongqing University of Posts and Telecommunications Chongqing China institute of Advanced Network Technology and New Serives (ANTS) University of Science and Technology Beijing Beijing China

Survivability for multi-domain optical networks is becoming a key parameter due to expanding network. In order to provide the shared-path-protected lightpath in multi-domain optical mesh networks, we propose a protection solution, called GSLSSP. A new source egress gateway selecting mechanism is adopted in this solution. For each connection request, this mechanism can enable the source node to select a better egress gateway node to the destination domain and compute one inter-domain working path near the optimal path with the cooperating of this gateway node, under scalability and domain privacy constraint of multi-domain networks. And then one intra-domain link-disjoint local segment-backup path for each working-segment path is computed out in each single-domain passed by the working path. Simulation evaluation shows that the proposed scheme can provide 100% protection ability for multiple failures. Besides, it is effective in multi-domain path protection with more efficient resource utilization, lower blocking probabilities and less inter-domain cost than other schemes.

关键词： survivability optical mesh networks multi-domains multiple failures segment-shared protection

Studies on Carbohydrates ⅩⅩⅧ. Synthesis of key Intermediates of Oligosaccharides Related to Serratia marcescens O10 Antigen

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chinese Chemical Letters 1998年第5期9卷 435-437页

作者： Ke Qin ZHANG Jian Min MAO Hong Min CHEN Meng Shen CAI(School of Pharmaceutical sciences, beijing Medical University, beijing 100083) School of Pharmaceutical sciences Beijing Medical University Beijing 100083 China

In the continuation of our study on the Serratta marcescens O-antigen, two disaccharides8 and 13, corresponding to the key intermediates of oligosaccharides related to the S. marcescensO10 antigen, were srythesized by the trichloroacetate method. Their structures and compositionswere characterized by H NMR, C NMR, 2D NMR and IR, FAB-MS spectra.

关键词： synthesis Serratia marcescens O10 antigen trichloroacetate

Critical condition study of borehole stability during air drilling

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Petroleum Science 2009年第2期6卷 158-165页

作者： Deng Jingen Zou Linzhan Tan Qiang Yan Wei Gao Deli Zhang Hanlin Yan Xiuliang MOE key laboratory of Petroleum Engineering China University of Petroleum Beijing 102249 China Drilling Research institute of Changqing Oilfield Xi＇an Shaanxi 710048 China Drilling Research institute of Shengli Oilfield Dongying Shandong 257100 China

The purpose of this paper is to establish the existence of the critical condition of borehole stability during air drilling. Rock Failure Process Analysis Code 20 was used to set up a damage model of the borehole excavated in strain-softening rock. Damage evolution around the borehole was studied by tracking acoustic emission. The study indicates that excavation damaged zone （EDZ） is formed around borehole because of stress concentration after the borehole is excavated. There is a critical condition for borehole stability; the borehole will collapse when the critical damage condition is reached. The critical condition of underground excavation exists not only in elastic and ideal plastic material but in strainsoftening material as well. The research is helpful to developing an evaluation method of borehole stability during air drilling.

关键词： Borehole stability air drilling critical condition

Research on Ranking Support Vector Machine and Prospects

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Research on Ranking Support Vector Machine and Prospects

Theoretical and experimental study of the pulling force of jet bits in radial drilling technology

第二十九届中国控制会议

作者： DING Shi-Fei 1,2,LIU Xiao-Liang 1,ZHANG Li-Wen 1 1.School of Computer Science and Technology,china University of Mining and Technology,Xuzhou 221008,P.R.china 2.key laboratory of Intelligent Information Processing,institute of Computing Technology,chinese academy of sciences,beijing 100080,P.R.china

Learning to rank is designed to determine a ranking for the target objects according to some ***,the problem about learning to rank is to learn a ranking function from a training set whose data has been *** is most applied to the social sciences and information *** to rank is a hot issue in the field of information retrieval and machine learning at *** paper analyses the process of Ranking Support Vector machine（RSVM）from a theoretical point of view from the classification and regression respectively,and sets up the two basic mathematical models about *** general introduction about RSVM in the application,training speed and generalization ability is also *** the end,we come to a conclusion.

关键词： Support Ector Machine(SVM) Ranking SVM(RSVM) Learning to Rank Ordinal Regression

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Petroleum Science 2009年第4期6卷 395-399页

作者： Ruichang Guo Gensheng Li Zhongwei Huang Shouceng Tian Xiaoning Zhang Wei Wu china Univ Petr State Key Lab Petr Resources & Prospecting Beijing 102249 Peoples R China

Radial drilling technology, of which the jet bit is the key device, is a research focus in the field of oil drilling and production. This paper establishes mechanical equations for jet bits and analyzes the hydroseal of backward jets in bottom holes. Meanwhile this paper establishes a mechanical equation for a high pressure hose and analyzes the axial force distribution. laboratory experiments indicate that the flow rate, the angle between the backward nozzle axis and the jet bit axis, and the hole diameter are the major influencing factors; the generation of the pulling force is mainly due to the inlet pressure of the jet bit; the backward jets can significantly increase not only the pulling force but also the stability of jet bits. The pulling force would reach 8,376 N under experimental conditions, which can steadily pull the high-pressure hose forward.

关键词： Radial drilling water jet jet bit depression effect pulling force

菜地和旱作粮地土壤氮素矿化和硝化作用的比较

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土壤通报 2005年第1期36卷 41-44页

作者：贺发云尹斌蔡贵信金雪霞李辉信中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室江苏南京210008 中国科学院研究生院北京南京农业大学资源与环境学院江苏南京210095

采用室内培养试验研究了南京郊区菜地和早作粮地土壤氮素矿化和硝化作用的特征,其菜地土壤是20年前从粮食作物改种为蔬菜的。结果表明,菜地土壤氮素矿化量和矿化率都显著高于相应的粮地土壤。改制对硝化作用没有固定的影响,其硝化作用... 详细信息

采用室内培养试验研究了南京郊区菜地和早作粮地土壤氮素矿化和硝化作用的特征,其菜地土壤是20年前从粮食作物改种为蔬菜的。结果表明,菜地土壤氮素矿化量和矿化率都显著高于相应的粮地土壤。改制对硝化作用没有固定的影响,其硝化作用是增强还是减弱主要取决于土壤pH是上升或下降。土壤氮素的矿化和硝化速率受土壤速效磷、速效钾、有机质含量和pH的影响。

关键词：菜地氮素矿化作用硝化作用旱作粮地

Numerical Simulation of Earthquake Nucleation Process and Seismic Precursors on Faults

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Earthquake Research in china 2000年第3期14卷 6-19页

作者： He Changronginstitute of Geology & laboratory of Tectonophysics, china Selsmological Bureau, beijing 100029, china institute of Geology & laboratory of Tectonophysics China Seismological Bureau Beijing 100029 China

To understand precursory phenomena before seismic fault sliP,this work focuses onearthquake nucleation process on a fault plane through numerical *** and statedependent friction law with variable normal stress is employed in the *** resultsshow that in the late stage of nucleation process:(1)The maximum slip velocity ismonotonically accelerating;(2)The slipping hot spot(where the slip rate is maximum)migrates spontaneously from a certain instant,and such migration is spatially continuous;(3)When the maximum velocity reaches a detectable order of magnitude(at least one orderof magnitude greater than the loading rate),the remaining time is 20 hours or longer,andthe temporal variation of slip velocity beyond this point may be used as a precursoryindicator;(4)The average slip velocity is related to the remaining time by a log-log linearrelation,which means that a similar relation between rate of microseismicity and remainingtime may also exist;(5)when normal stress variation is taken

关键词： Fault Earthquake nucleation Friction Numerical simulation