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Characterization of different-Al-content AlGaN/GaN heterostructures on sapphire

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Science china(Physics,{1. & Astronomy) 2010年第1期53卷 49-53页

作者： DING GuoJian , GUO LiWei, XING ZhiGang, CHEN Yao, XU PeiQiang, JIA HaiQiang, ZHOU JunMing & CHEN Hong beijing National Laboratory of Condensed Matter Physics, {1. of Physics, Chinese Academy of Sciences, beijing 1.01.0, china 1. beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

Al x Ga 1.x N/GaN high-electron-mobility transistor (HEMT) structures with Al composition ranging from x = 0.1. to 0.36 are grown on sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The effects of Al content on crystal quality, surface morphology, optical and electrical characteristics of the AlGaN/GaN heterostructures have been analyzed. Although high Al-content (36%) heterostructure exhibits a distinguished photoluminescence peak related to recombination between the two-dimensional electron gas and photoexcited holes (2.EG-h), its crystal quality and rough surface morphology are poor. 2.EG mobility increases with the Al content up to 2.% and then it apparently decreases for high Al-content (36%) AlGaN/GaN heterostructure. The increase of sheet carrier density with the increase of Al content has been observed. A high mobility at room temperature of 2.05 cm 2./V s with a sheet carrier density of n s = 1.1. × 1. 1. cm -2., for a 2.% Al-content AlGaN/GaN heterostructure has been obtained, which is approaching state-of-the-art for HEMT grown on SiC. Sheet resistance as low as 2.4 Ω/□ has also been achieved.

关键词： AlGaN Hall-effect luminescence

Establishment of Statistical Model for Precipitation Prediction in the Flood Season in china

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Meteorological and Environmental Research 2011年第3期2卷 1-3页

作者： CHENG Zhi1.2.1.College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,{1. 2.Key Laboratory for Climate-Environment in East Asian Region,{1. of Atmospheric Physics,Chinese Academy of Sciences,{2. 1.002.,{1.

[Objective] The research aimed to establish the regression model which was used to predict the precipitation in the flood season in china.[Method] Based on statistical model,North Atlantic oscillation index and the sea surface temperature index in development and declining stages of ENSO were used to predict East Asian summer monsoon *** the stations were divided into 1. zones,the same factors were used to establish the regression model predicting the station precipitation in the flood season in ***,it was compared with the model that predicted firstly the monsoon index and estimated the precipitation.[Result] The prediction results of summer precipitation during {1.05-{1.09 by every model were *** was found that the model that the factor predicted indirectly the regional precipitation was better than that predicted indirectly the station ***,the model that the factor predicted directly the regional precipitation was better than that predicted indirectly the regional *** prediction score P of optimum model that three factors predicted directly the regional precipitation reached averagely 74.{1.and the anomaly correlation coefficient ACC was averagely *** from the comparison situation of positive and negative zone distribution of precipitation anomaly percentage between the predicted and observed values in 5 years,the prediction effects in the south and east of Northeast china,some areas in the south of Yangtze River,the coast of South china and most areas of Xinjiang were *** predicted positive/negative distribution of precipitation anomaly percentage tallied with that of observation.[Conclusion] The model could predict well summer precipitation in china.

关键词： East Asian monsoon index Linear regression Summer precipitation ENSO North Atlantic oscillation index china

Identification of the nuclear matrix and chromosome scaffold in dinoflagellate Crythecodinium cohnii

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Cell Research 1992年第2期2卷 165-181页

作者： CAT SHUTAO , CONGMEI ZENG, JINGYAN LI AND ZHONGHE ZHAI Department of Biology, beijing University, beijing 1.0871.{2.. Kunming institute of Zoology, Academia Sinica, Kunming 6501.7,{2.. Department of Biology Beijing University Beijing China Kunming institute of Zoology Academia Sinica Kunming China

Dinoflagellate is one of the primitive eukaryotes,whosenucleus may represent one of the transition stages fromprokaryotic nucleoid to typical eukaryotic *** extraction together with embeddment-free sectionand whole mount electron microscopy,a delicate nuclearmatrix filament network was shown,for the first time,indinoflagellate Crypthecodinium cohnii *** are connected with nuclear matrix filaments to forma complete network spreading over the ***,we demonstrated that the dinoflagellate chromosome retainsa protein scaffold after the depletion of DNA and *** scaffold preserves the characteristic mor-phology of the *** dimensional elec-trophoreses indicated that the nuclear matrix and chromo- some scaffold are mainly composed of acidic *** demonstrated that a framework similar to the nuclearmatrix and chromosome scaffold in mammalian cells appearsin this primitive eukaryote,suggesting that these structuresmay have been originated from the early stages of eukaryoteevolution.

关键词： nuclear matrix chromosome scaffold dinoflagellate Crypthecodinium cohnii.

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构造圈闭在柴东天然气成藏中的控制作用

天然气工业 2004年第10期24卷 17-19页

作者：马达德陈新领寇福德李军石油大学.北京中国石油青海油田分公司勘探开发研究院

背斜构造圈闭是天然气藏的主要圈闭类型,在柴达木盆地已找到多个大型生物气田,近几年勘探目标转移到低幅度构造圈闭气藏的勘探上,圈闭有效性的评价成为重点。柴达木生物气成藏过程中具有水溶气藏到纯气藏的发展特征,根据水溶气释放的特... 详细信息

背斜构造圈闭是天然气藏的主要圈闭类型,在柴达木盆地已找到多个大型生物气田,近几年勘探目标转移到低幅度构造圈闭气藏的勘探上,圈闭有效性的评价成为重点。柴达木生物气成藏过程中具有水溶气藏到纯气藏的发展特征,根据水溶气释放的特点和有关模拟实验的结果,结合柴达木盆地东部涩北气田的地质特征进行了不同圈闭幅度构造的储量估算和对比。模拟计算结果表明,除生烃强度外,背斜圈闭的闭合幅度对气藏的储量规模具有明显的控制作用,随闭合幅度减小,储量规模急剧减少。建议勘探新的气藏应立足于在生烃能力强的地区寻找闭合幅度比较大的构造圈闭。同时通过类比和模拟计算可以为储量估算研究提供一种可行的评价方法。

关键词：构造圈闭天然气藏低幅度构造生烃能力柴达木盆地水溶气背斜储量规模天然气成藏圈闭类型

Cloning and characterization of vernalization-related gene (ver2.3F) cDNA 3'end

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Chinese Science Bulletin 1999年第14期44卷 1289-1294页

作者： YONG Weidong, CHONG Kang , LIANG Tiebing, XU Zhihong , TAN Kehui and ZHU Zhiqing Research Center for Molecular and Developmental Biology, institute of Botany, Chinese Academy of Sciences , {1. 1.0093,{2. Shanghai institute of Plant Physiology , Chinese Academy of Sciences , Shanghai 2.0032.{2. Corresponding authors Research Center for Molecular and Developmental Biology Institute of Botany Chinese Academy of Sciences Beijing China Shanghai institute of Plant Physiology Chinese Academy of Sciences Shanghai China

Based on the cDNA fragment sequence of vernalization-related gene verc2.3 cloned by differential screening in our lab, the 5′primer has been designed. The cDNA 3′end of ver2.3 gene (1.1.7 bp) has been cloned by the RACE method. And it is identified by Northern blotting that its expression is special in vernalization treatment. After comparing the sequence in the nucleotide sequence databases of Genbank, EMBL and DDBJ, the gene has homology with Hordeum vulgare jesmonate-induced protein gene. It is suggested that this gene might be related to the signal transduction mediated by jamonate.

关键词： wheat vernalization-related gene cDNA 3’ end RACE.

Modification Design of High-precision Above Ground Marking System

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Modification Design of High-precision Above Ground Marking S...

2.1. Chinese Control and Decision Conference

作者： Liying Sun~(1.2.,Yibo Li~1.Gang Du~1.Weikui Wang~1.Yuankai Zhang~3 1.State Key Lab.of Precision Measurement Technology and Instrument Tianjin University Tianjin,300072.china 2.Department of Energy and {1. Engineering,Tianjin {2. of Urban Construction,Tianjin,300384,china 3.{2. of Acoustics,Chinese Academy of Sciences,beijing 1.01.0,china

＜正＞Above ground marking system is one of the three main components of Magnetic Flux Leakage Detector, which is widely used in safety and integrity assessment of long-range transmission *** analyzing the advantages and disadvantages of three types of former above ground marking systems,a high-precision above ground marking system with smart appearance,intelligent communication and low cost is designed to eliminate the accumulated errors caused by mechanical construction,turning or slippage of the miles round of the magnetic Flux Leakage Detector. Hardware design of the new above ground system,including above ground marker and master clock system,is investigated in detail in this paper and reliable experiments and traction tests were performed to test the stability and dependability of the system.

关键词： Above Ground Marker Master clock hardware design Magnetic Flux Leakage Detector

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森林生态系统的水源涵养功能及其计量方法

生态学杂志 2009年第3期28卷 529-534页

作者：张彪李文华谢高地肖玉中国科学院地理科学与资源研究所北京100101 中国科学院研究生院北京100039

为全面认识与正确评价森林生态系统的水源涵养功能,本文探讨了其概念、表现形式及其计量方法,认为:1.森林的水源涵养功能是一个动态、综合的概念,随着人们对森林水文作用认识的不断深入,其内涵不断丰富扩大,因此森林的水源涵养功能概念... 详细信息

为全面认识与正确评价森林生态系统的水源涵养功能,本文探讨了其概念、表现形式及其计量方法,认为:1.森林的水源涵养功能是一个动态、综合的概念,随着人们对森林水文作用认识的不断深入,其内涵不断丰富扩大,因此森林的水源涵养功能概念存在狭义和广义之分;2.森林的水源涵养功能(广义)有多种表现形式,包括拦蓄降水、调节径流、影响降雨和净化水质等,不过其具体表现形式与研究对象、研究目的以及研究尺度有关;3)目前森林拦蓄降水功能的计量方法主要有土壤蓄水能力法、水量平衡法、年径流量法和多因子回归法等8种,不过这些方法都存在一定的局限性,实际应用中需要综合考虑。

关键词：森林生态系统水源涵养功能表现计量方法

Structural stability of C60 films under the bombardment of 1.95 GeV Kr ions

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Science Bulletin 2010年第31期 3532-3536页

作者： YAO CunFeng1.2.FU YunChong3,JIN YunFan1.,WANG ZhiGuang1.ZANG Hang1.2.WEI KongFang1.GOU Jie1.MA YiZhun1.2.& SHEN TieLong1.2.1.institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,{1. 2.Graduate University of Chinese Academy of Sciences,{2. 1.0049,{1. 3 institute of Earth Environment,Chinese Academy of Sciences,Xi'an 71.075,{1.

The structural stability of C60 films under the bombardment of 1.95 GeV Kr ions is *** irradiated C60 films were analyzed by Fourier Transform Infrared(FTIR) spectroscopy and Raman scattering *** analytical results indicate that the irradiation induced a decrease of icosahedral symmetry of C60 molecule and damage of C60 films;different vibration modes of C60 molecule have different irradiation sensitivities;the mean efficient damage radius obtained from experimental data is about 1.47 nm,which is in good agreement with thermal spike model prediction.

关键词： 1.95 GeV Kr ions C60 films structural stability efficient damage radius thermal spike model

Simulation of interplanetary scintillation with SSSF and SSDF mode

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Science china(Physics,{1. & Astronomy) 2010年第1期53卷 187-192页

作者： LIU LiJia & PENG Bo National Astronomical Observatories, Chinese Academy of Sciences, beijing 1.001.1.{1. 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The sun has the biggest effect on the Earth in many ways. Observing the solar wind is an important method to study the solar-earth environment. Ground-based interplanetary scintillation observations are an effective method of monitoring solar wind speed, studying the random fluctuations of the interplanetary plasma and the structures of radio sources. Two modes of single-station observations, namely, single station-single frequency (SSSF) and single station dual-frequency (SSDF), are briefly introduced and numerically simulated in this paper. The SSSF mode are easier to carry out and has been widely used. Although the observing system and data processing system of the SSDF mode are more complicated, it can measure the solar wind speed more accurately. A new SSDF system is under construction in Miyun, NAOC (the National Astronomical Observatories, Chinese Academy of Sciences), with a 50 m telescope, which will serve the Meridian Project, and this paper is devoted to preparing for this new system.

关键词： interplanetary scintillation single station-single frequency single station dual-frequency simulation