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The Age and Character of the Yu'erhong Flora from Yumen, Gansu

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Acta Geologica Sinica(English Edition) 1995年第3期69卷 329-338,342-343页

作者： Shen Guanglong, Wu Xiuyuan, Wang Jun and Liu Huaqin Department of Geology, Northwest U niversity, Xi’an, Shaanxi nanjing institute of Geology and Palaeontology,Chinese {2. of {3.s, nanjing, Jiangsu 1 Department of Geology Northwest University Xi' an Shaanxi2Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing Jiangsu

From a fresh field investigation, it has been ascertained that the Late Palaeozoic Yu'erhong (Yuernhung) flora from Yu'erhong, Yumen, Gansu, northwestern china, studied by Bohlin in 1971 includes plants from the Westphalian Yangfukou Formation and the Stephanian to Sakmarian Taiyuan Formation. The Yu'erhong flora from the Yanghukou Formation is dominated by Euramerican elements with a few elements of the Cathaysian flora. No Angarian elements have be found in this section for lack of Late Permian strata. The specimens studied by Bohlin might possibly come from the upper part of the Upper Permian at tne southeastern corner . of the Yu'erhong basin. Those fossils from different horizons and localities might be mixed with each other during collection ;so they fail to reflect the exact horizon of certain plant fossils.

关键词： Yu'erhong flora Yanghukou Formation Taiyuan Formation Yumen Gansu

Influences of Quinclorac on Culturable Microorganisms and soil Respiration in Flooded Paddy soil

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Biomedical and Environmental sciences 2003年第4期16卷 314-322页

作者： ZHEN-MEI LU, HANG MIN , AND YANG-FANG YE institute of Microbiology, College of Life science, Zhejiang University, Hangzhou {2.002., Zhejiang, china institute of Microbiology College of Life Science Zhejiang University Hangzhou 310029 Zhejiang China

Objective To investigate the potential effects of herbicide quinclorac (3.7-dichloro-8-quinoline-carboxylic) on the culturable microorganisms in flooded paddy soil. Methods Total soil aerobic bacteria, actinomycetes and fungi were counted by a 10-fold serial dilution plate technique. Numbers of anaerobic fermentative bacteria (AFB), denitrifying bacteria (DNB) and hydrogen-producing acetogenic bacteria (HPAB) were numerated by three-tube anaerobic most-probable-number (MPN) methods with anaerobic liquid enrichment media. The number of methanogenic bacteria (MB) and nitrogen-fixing bacteria (NFB) was determined by the rolling tube method in triplicate. soil respiration was monitored by a 102.-type gas chromatography with a stainless steel column filled with GDX-104 and a thermal conductivity detector. Results Quinclorac concentration was an important factor affecting the populations of various culturable microorganisms. There were some significant differences in the aerobic heterotrophic bacteria. AFB and DNB between soils were supplemented with quinclorac and non-quinclorac at the early stage of incubation, but none of them was persistent. The number of fungi and DNB was increased in soil samples treated by lower than 1.3.μg·g-1 dried soil, while the CFU of fungi and HPAB was inhibited in soil samples treated by higher than 1.3.μg·g-1 dried soil. The population of actinomycete declined in negative proportion to the concentrations of quinclorac applied after 4 days. However, application of quinclorac greatly stimulated the growth of AFB and NFB. MB was more sensitive to quinclorac than the others, and the three soil samples with concentrations higher than 1 μg·g-1 dried soil declined significantly to less than 40% of that in the control, but the number of samples with lower concentrations of quinclorac was nearly equal to that in the control at the end of experiments. Conclusion Quinclorac is safe to the soil microorganisms when applied at normal concentrations (0.67

关键词： Quinclorac soil culturable microorganisms soil respiration Flooded paddy soil

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汶川地震后四川安县甘沟堵溃泥石流及其对策

山地学报 2011年第3期29卷 320-327页

作者：游勇陈兴长柳金峰中国科学院山地灾害与地表过程重点实验室中国科学院水利部成都山地灾害与环境研究所西南科技大学环境与资源学院

汶川地震诱发的大量崩塌和滑坡不仅直接为泥石流活动提供松散固体物质,还可能造成沟道堵塞。沟道内的堵塞坝虽然不像主河道上的堰塞湖那样造成大范围灾害,但溃决后却会引发大规模泥石流,给人民生命财产和基础设施等造成严重危害。以四... 详细信息

汶川地震诱发的大量崩塌和滑坡不仅直接为泥石流活动提供松散固体物质,还可能造成沟道堵塞。沟道内的堵塞坝虽然不像主河道上的堰塞湖那样造成大范围灾害,但溃决后却会引发大规模泥石流,给人民生命财产和基础设施等造成严重危害。以四川省安县高川乡甘沟为例,说明其造成泥石流的危害特征及防治对策。通过对甘沟自然环境背景条件的分析,发现甘沟具备泥石流暴发的地形地貌和降水条件;流域内地震诱发的崩滑体不仅为泥石流的形成提供丰富的松散固体物质,还造成沟道堵塞,形成堵溃型泥石流。甘沟已建的排导槽存在过流能力不够、槽底和侧墙已基本被破坏、弯道处未考虑超高、沟内未布置拦挡工程等问题。目前沟内由于松散固体物质充足,在一定的降水条件下,仍会再次暴发泥石流。针对甘沟的具体情况,提出了修建拦挡、重建排导槽并结合预警预报措施的防治对策,并对重建排导槽的过流断面进行了优化设计。

关键词：安县甘沟堵溃泥石流防治对策断面优化设计

Development of Trusted Network and Challenges It Faces

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ZTE Communications 2008年第1期6卷 13-17页

作者： Lin Chuang 1, Wang Yuanzhuo 1, Tian Liqin 1,2.(1. Department of Computer science and Technology, Tsinghua University, Beijing 100084, china 2. Department of Computer, North china {3. of science and Technology, Beijing 101601, china)

As the information network plays a more and more important role globally, the traditional network theories and technologies, especially those related to network security, can no longer meet the network development requirements. Offering the system with secure and trusted services has become a new focus in network research. This paper first discusses the meaning of and aspects involved in the trusted network. According to this paper, the trusted network should be a network where the network’s and users’ behaviors and their results are always predicted and manageable. The trustworthiness of a network mainly involves three aspects: service provider, information transmission and terminal user. This paper also analyzes the trusted network in terms of trusted model for network/user behaviors, architecture of trusted network, service survivability and network manageability, which is designed to give ideas on solving the problems that may be faced in developing the trusted network.

关键词： Development of Trusted Network and Challenges It Faces

Gaining effciency via weighted estimators for multivariate failure time data

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science china Mathematics 2009年第6期52卷 1113-1128页

作者： FAN JianQing1,2.ZHOU Yong2.3.CAI JianWen4 & CHEN Min3.1 Department of Operations Research and Financial Engineering,Princeton University,Princeton,NJ08544,USA 2.Department of Statistics,Shanghai University of Finance and Economics,Shanghai 2.043.,china 3.institute of Applied Mathematics,academy of Mathematics and Systems {3.,Chinese academy of Sci-ences,Beijing 100190,china 4 Department of Biostatistics,University of North Carolina at Chapel Hill,Chapel Hill,NC 2.599-742.,USA

Multivariate failure time data arise frequently in survival analysis.A commonly used tech-nique is the working independence estimator for marginal hazard *** natural questions are how to improve the effciency of the working independence estimator and how to identify the situations under which such an estimator has high statistical *** this paper,three weighted estimators are proposed based on three different optimal criteria in terms of the asymptotic covariance of weighted ***-form solutions are found,which always outperform the working indepen-dence *** also prove that the working independence estimator has high statistical effciency,when asymptotic covariance of derivatives of partial log-likelihood functions is nearly exchangeable or *** are conducted to compare the performance of the weighted estimator and work-ing independence estimator.A data set from Busselton population health surveys is analyzed using the proposed estimators.

关键词： marginal hazard model pseudo-partial likelihood working independence estimator optimal weight

Influence of TiO_2.seeding layers on phase composition of lead magnesium niobate-lead titanate thin films prepared by RF magnetron sputtering

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Rare Metals 2007年第S1期26卷 205-209页

作者： WANG Junming,LI Weili,and FEI Weidong School of Materials science & Engineering,Harbin institute of Technology,Harbin 150001,{2. Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

The influence of amorphous TiO_2.seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3.b2.3.O3.0.3.bTiO3.PMN-PT) films deposited on Pt/Ti/SiO2.Si substrate by RF magnetron sputtering was *** relation between seeding layer thickness and phase composition at different post annealing temperature was observed by *** thickness of amorphous TiO2.seeding layer and post annealing temperature had remarkable effects on PMN-PT film phase *** amorphous seeding layer becomes thick,a new phase of Nb2.5 exists in the *** when the seeding layer thickness is suitable,the film with pure perovskite phase can be attained.

关键词： PMN-PT film amorphous TiO_2.seeding layers RF magnetron sputtering

Preparation and ASE Spectrum of a Single-Mode Erbium Doped Tellurite Glass Fiber with D-type Cladding Geometry

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Journal of Materials science & Technology 2004年第6期20卷 671-674页

作者： Junjie ZHANG, Shixun DAI, Guonian WANG, Shiqing XU, Shunguang LI and Lili HUShanghai institute of Optics and Fine Mechanics, Chinese academy of {2.s, Shanghai 2.1800,{3. Inst. of Optics and Fine Mech. Chinese Acad. of Sci. Shanghai 201800 China

Based on the host of tellurite glasses, the glass formation, preform manufacture, and fiber fabrication are described. The characterization of amplified spontaneous emission (ASE) from this newly fabricated single-mode Er3.-doped tellurite fibers is also presented. When pumped at 980 nm, a very broad erbium ASE around 1.53.μm was observed. The variations of ASE with fiber length and pumping power are measured and discussed. The output of 2.mW from Er3.-doped tellurite fiber ASE source was obtained under the pump power of 660 mW.

关键词： Preparation ASE spectrum Er^(3.) Tellurite glass fiber

Theoretical critical value curve and driving force formation of ecological migration in the arid land

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Chinese science Bulletin 2006年第A01期51卷 196-203页

作者： ZHU Zi’an & ZHANG Xiaolei Xinjiang institute of Ecology and Geography, Chinese academy of {2.s, Urumqi 83.011,{3. The Graduate School of the Chinese academy of {2.s, Beijing 10003.,{3. Xinjiang Uygur Autonomous Region Development and Reform Commission, Urumqi 83.002.{3. Chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China Xinjiang Uygur Autonomous Reg Dev & Reform Commis Urumqi 830002 Peoples R China

干旱陆地的易碎的 eco 环境的特征确定它骚乱抵抗的能力更低。在干旱陆地的自然荒芜的绿洲在在宽 Gobi 沙漠散布的马赛克补丁。人口分发是极大地依赖于水资源。人口与驱散的分发，简单生产和生活被描绘风格，和贫穷和遥远。生态的迁居... 详细信息

干旱陆地的易碎的 eco 环境的特征确定它骚乱抵抗的能力更低。在干旱陆地的自然荒芜的绿洲在在宽 Gobi 沙漠散布的马赛克补丁。人口分发是极大地依赖于水资源。人口与驱散的分发，简单生产和生活被描绘风格，和贫穷和遥远。生态的迁居被执行的原因躺在生态的问题。生态的降级是生态的迁居的主要驱动力。然后，驱动力的力量取决于生态的降级的度。因此，是否执行生态的移植取决于生态的降级的程度。理论上，为在干旱陆地的精明的生态的移植的批评的值曲线通过生态学的相对问题的全面研究被提出，经济等等，在干旱陆地与生态的移植经验结合了，并且基于干旱环境的特征。在这篇文章，与这条曲线，理论研究和生态的迁居的一些实践从不做作的行为和生态的移植的驱动力形成的政府行为的观点被做了。它分析活跃驱动力(因素) 和否定力量(因素) ，并且指出预定和在干旱陆地实现生态的迁居的步骤。理论曲线表达某些创见和适用性，它为为实现生态的迁居工程评估生态的降级和理论底的度提供一个量的方法。

关键词：生态迁移临界值驱动力贫瘠地

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土壤对铜离子的专性吸附及其特征的研究

土壤学报 1989年第1期26卷 31-41页

作者：武玫玲中国科学院南京土壤研究所

供试土壤专性吸附铜的等温线均符合Langmuir方程。红壤吸附量最低,砖红腹与黄泥土最大吸附量相近,但在铜浓度低时砖红壤吸铜量远低于黄泥土,而在高浓度则反之。土壤专性吸附铜是在溶液中Na^+浓度比Cu^(2.)高8.3.100倍条件下,Na^+离子... 详细信息

供试土壤专性吸附铜的等温线均符合Langmuir方程。红壤吸附量最低,砖红腹与黄泥土最大吸附量相近,但在铜浓度低时砖红壤吸铜量远低于黄泥土,而在高浓度则反之。土壤专性吸附铜是在溶液中Na^+浓度比Cu^(2.)高8.3.100倍条件下,Na^+离子仍不足以与之竞争的那些专性吸附点所吸持的铜。按其解吸条件区分为松结合铜(可为N NH_4Cl解吸)和紧结合铜(仅能为0.1 N HCl解吸)两种。紧结合铜受平衡溶液铜浓度影响很小,所占据的吸附点对Cu^(2.)有较强亲和力。松结合铜则随平衡铜溶液浓度增大而增加,符合Langmuir方程。对于砖红壤和黄泥土,在铜浓度低时紧结合铜>松结合铜;浓度高时则反之。红壤专性吸附铜始终以松结合铜为主。三种土壤比较,紧结合铜是砖红壤>黄泥土>红壤;松结合铜则是黄泥土>砖红壤>红壤。造成这些差别的原因可能与土壤性质、氧化物、有机质和粘土矿物组成等不同有关。用平衡法研究三种土壤专性吸附铜在不同浓度NH_4Cl和HCl溶液中的解吸表明,可进一步区分为三或四种不同的结合状况。红壤对铜吸附容量最小,且最易解吸。

关键词：土壤铜离子专性吸附