40Ar/39Ar Geochronology of Weathering Process in the Tu-Ha Basin, Northwest China     

YANG Jing  CHEN Wen  ZHENG Dewen  YANG Li  ZHANG Yan  LIU Xinyu 《《地质学报》英文版》2015,89(6):2094-2095

<正>The Asian interior contains the most regionally extensive areas of mid-latitude deserts and semi-deserts in the word,and its timing and forcing mechanisms of aridification has attracted much attention.The Tu-Ha Basin is one of the major hyperarid areas in the northwestern China;however,the initiation and history of aridification of this basin have been poorly understood.  相似文献   

应用雷达拼图数据估测降水试验     

伍静  刘黎平  尤卫红  崔哲虎 《海洋学研究》2010,(1)

利用2008年6月5～7日广东省新一代天气雷达网(广州、梅州、韶关、阳江、深圳及汕头6部雷达)的雷达原始体扫资料及自动雨量站资料,对广东省3 km高度上的雷达网系统观测值差异进行了分析,发现广州雷达的观测值比周围雷达偏高1～3 dBz,梅州雷达比其周围雷达的观测值偏低1～2 dBz。用Z-R关系和最优插值校准法分别进行6 min和1 h估测降水,并用面雨量偏差和均方根误差对该次降水估测试验做了简单评估。结果显示:6 min定量估测降水,两种方法都会低估,面雨量越大,估测效果越好;对于1 h定量估测降水,各种估测方法都有偏高或偏低情况,但普遍偏高,其中用先累加再用最优插值校准法校准的雷达-雨量计联合估测方法效果最好;短时降水估测可以很好地反映降水过程变化,而长时间降水估测可以较准确估测降水大小。  相似文献   

天气雷达定量测量中若干问题的讨论     

徐宝祥  李银海  蔡启铭 《高原气象》1983,(2)

本文总结了1972—1978年对3.2厘米天气雷达的标定工作,讨论了标定在雷达定量测量中的重要性。主要结论是: (1)雷达参数逐年有变化,必须经过标定后才能进行定量测量。雷达一经安装固定,几个对测量Ze有影响的因子中,变动较大的是Pr_(min)。对本雷达,在冰雹季节内用讯号发生器校准,Pr_(min)变动不超过3分贝。由此所得Ze值的最大变幅为±2分贝 (2)施放携带标准反射体的气球,可以直接标定出给定距离上气象目标物的雷达最小可测反射率因子Ze_(min)值,由此计算所得Ze值的最大变幅为±1分贝。此法简便、实用,并且排除了雷达高频系统变动的影响。  相似文献   

RESEARCH ON LASER RANGE SCANNING AND ITS APPLICATION   总被引：5，自引：0，他引：5  

LI Qingquan LI Bijun CHEN Jing 《地球空间信息科学学报》2001,4(1):37-42

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓｌａｓｅｒｒａｎｇｅｓｃａｎｎｅｒ ,ｗｈｉｃｈｉｓｏｎｅｒｅｐｒｅｓｅｎｔａｔｉｖｅｏｆｔｈｅｈｉｇｈａｎｄｎｅｗｔｅｃｈｎｏｌｏｇｙｉｎ ｄｕｓｔｒｉｅｓ,ｈａｓｂｅｅｎｍａｋｉｎｇ ｇｒｅａｔｐｒｏｇｒｅｓｓｉｎｒｅａｌ＿ｔｉｍｅａｃｑｕｉｓｉｔｉｏｎｏｆｍｕｌｔｉ＿ｌｅｖｅｌｏｆ 3Ｄｓｐａｔｉａｌｏｂｊｅｃｔ.Ａｉｒｂｏｒｎｅｓｙｓｔｅｍ ,ｃｏｍｂｉｎｅｄｗｉｔｈｏｔｈｅｒｐｏｓｉｔｉｏｎｉｎｇｔｅｃｈｎｏｌｏｇｙｓｕｃｈａｓＧＰＳ ,ＩＮＳ …  相似文献   

双线偏振雷达在水文预报领域的应用——实时水文预报系统的研制     

刘黎平  钱永甫  王致君 《高原气象》1996,(4)

根据１９８０—１９８７年巴家咀水库流域各水文站及雨量站的流量和降雨强度资料，建立了一个利用中国科学院兰州高原大气物理研究所平凉雷达站的双线偏振雷达实时遥测降雨的雷达回波资料进行实时水文预报的模式。当接收到以无线电方式传输来的雷达资料后，该模式可进行包括各子流域的降雨总量、径流、汇流及到达水库的流量、洪峰流量和时间等水文参量的预报，并在计算机监视器上显示，在打印机上打印并存盘。这一方法与普通水文预报方法相比具有及时并能了解云发展趋势等优点。这一模式的建立及应用为防汛指挥、水库的调度提供了可靠、直观的依据，它将气象部门的高科技成果用于水文领域，开拓了气象雷达的应用范围，使雷达在暴洪监测中更好地发挥作用  相似文献   

Isolation and identification of a marine killer yeast strain YF07b and cloning of the gene encoding killer toxin from the yeast   总被引：1，自引：0，他引：1  

WANG Xianghong  CHI Zhenming  LI Jing 《海洋学报(英文版)》2007,26(6):101-108

It was found that the marine yeast strain YF07b could secrete a large amount of killer toxin against a pathogenic yeast strain WCY which could cause milky disease in Portunus trituberculatus.The marine yeast strain YF07b was identified to be Pichia anomala according to the results of routine yeast identification and 18S rDNA and ITS sequences.The gene encoding killer toxin in the marine yeast strain YF07b was amplified by PCR technology.After sequencing,the results show that an open reading frame,consisting of 1 281 bp,encoded a presumed protein of 427 amino acids.The sequence of the cloned gene was found to have 99% match with that of the gene encoding killer toxin in Pichia anomalas strain K.A signal peptide including 17 amino acids appeared in the N-terminal domain of the killer toxin.Therefore,the mature protein consisted of 410 amino acids,its molecular mass was estimated to be 47.4 ku and its isoelctronic point was 4.5.  相似文献   

Experimental Study on Free Spanning Submarine Pipeline Under Dynamic Excitation   总被引：5，自引：0，他引：5  

LI  Xin 《中国海洋工程》2002,16(4):537-548

Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is con-structed in a seismically active region. The model experiment is performed on an underwater shaking tahle to simulate the response of submarine pipelines under dynamic input. In consideration of the effects of the terrestrial and submarine pipeline , water depth, support condition, distance from seabed, empty and full pipeline, and span on dynamic response, 120 groups of experiments are conducted. Affecting factors are analyzed and conclusions are drawn for reference. For the con-trol of dynamic response, the span of a submarine pipeline is by far more important than the other factors. Meanwhile, the rosponse difference between a submarine pipeline under sine excitation and that under random excitation exists in ex-periments.  相似文献   

Characteristic mode model of tropical Pacific Ocean and dynamic mechanism of El Nino     

Zhang Xiangdong  Huang Shisong  Zhang Jing 《海洋学报(英文版)》1995,14(4):485-498

Ｃｈａｒａｃｔｅｒｉｓｔｉｃ　ｍｏｄｅｍｏｄｅｌ　ｏｆ　ｔｒｏｐｉｃａｌ　Ｐａｃｉｆｉｃ　Ｏｃｅａｎ　ａｎｄ　ｄｙｎａｍｉｃ　ｍｅｃｈａｎｉｓｍ　ｏｆ　Ｅｌ　ＮｉｎｏＺｈａｎｇＸｉａｎｇｄｏｎｇ；ＨｕａｎｇＳｈｉｓｏｎｇ；ａｎｄＺｈａｎｇＪｉｎｇ（Ｒ...  相似文献   

REE Geochemistry of Fluorite from the Maoniuping REE Deposit, Sichuan Province, China： Implications for the Source of Ore-forming Fluids          下载免费PDF全文

HUANG Zhilong XU Cheng Andrew McCAIG LIU Congqiang WU Jing XU Deru LI Wenbo GUAN Tao XIAO Huayun 《《地质学报》英文版》2007,81(4):622-636

Fluorite is one of the main gangue minerals in the Maoniuping REE deposit,Sichuan Province,China.Fluorite with different colors occurs not only within various orebodies,but also in wallrocks of the orefield.Based on REE geochemistry,fluorite in the orefield can be classified as the LREE-rich,LREE-flat and LREE-depleted types.The three types of fluorite formed at different stages from the same hydrothermal fluid source,with the LREE-rich fluorite forming at the relatively early stage,the LREE-flat fluorite in the middle,and the LREE-depleted fluorite at the latest stage.Various lines of evidence demonstrate that the variation of the REE contents of fluorite shows no relation to the color.The mineralization of the Maoniuping REE deposit is associated spatially and temporally with carbonatite-syenite magmatism and the ore-forming fluids are mainly derived from carbonatite and syenite melts.  相似文献   

层状云和对流云的雷达识别及在估测雨量中的应用   总被引：10，自引：1，他引：10  

仲凌志  刘黎平  顾松山 《高原气象》2007,26(3):593-602

参考“峰值法”建立了利用新一代多普勒天气雷达回波强度识别混合型降水过程中层状云和对流云的方法,分析了反射率阈值和影响半径的变化对识别效果的影响,检验了识别效果,并分析该方法在雷达估测降水中的应用。表明本文所建立的暴雨中层状云和对流云识别方法基本合理,配合云的垂直结构分析大部分地区识别的效果较好,同时通过该识别方法对合肥2002年6月19日一次强降水天气过程的估测降水的应用,表明只按层状云的Z-I关系估测的雨强,相对于识别对流云和层状云后分别按各自的Z-I关系估测的单点雨强,其最大差别约达37%,相应的面雨量也有一定的差别;对流云的多少对发展的中尺度对流系统的雨强有很大影响,这次混合型降水过程以对流云降水为主。对流云和层状云是形成暴雨的重要因素,准确地识别两者,对估测降水的精度会有积极作用。  相似文献