利用EP/TOMS气溶胶指数分析中国和韩国的沙尘天气过程

利用 EP/TOMS卫星反演气溶胶指数、卫星云图和天气形势,研究了沙尘天气对大气气溶胶的贡献以及中国和韩国沙尘天气过程的强度及其演变。结果表明,TOMS气溶胶指数高值对应着沙尘天气的出现地区,可以判别和监测大规模沙尘天气,而且TOMS气溶胶指数能结合卫星云图、大气环流分析,对沙尘天气的影响范围和传输路径进行有效地预报。另外气溶胶指数能排除云的影响并准确地检测到云覆盖的地区。     

Sensitivity analysis of extended TOPMODEL for agricultural watersheds equipped with tile drains

An extension of TOPMODEL was developed for rainfall–runoff simulation in agricultural watersheds equipped with tile drains. Tile drain functions are incorporated into the framework of TOPMODEL. Nine possible flow generation scenarios are suggested for tile-drained watersheds and applied in the modelling procedure. In the model development, two methods of simulation of the flow in the unsaturated zone were compared: the traditional, physically based storage approach and a new approach using a transfer function. A regionalized sensitivity analysis was used to determine the sensitivity of parameters and to compare the behaviour of the transfer function with that of the simple storage-related formulation. The number of accepted combinations of parameter values, on average, was higher for the transfer function approach than when using a Monte Carlo method of parameter estimation. Since the rainfall–runoff response pattern tends to vary seasonally, seven events distributed throughout a year were used in the sensitivity analysis to investigate the seasonal variation of the hydrological characteristics. © 1997 John Wiley & Sons, Ltd.     

α-Glucosidase Inhibitory Activities of Lutein and Zeaxanthin Purified from Green Alga Chlorella ellipsoidea

α-Glucosidase inhibitors are used therapeutically to treat type-2 diabetes mellitus. Through a bioassay-guided fractionation technique, three carotenoids,(all-E)-lutein,(all-E)-zeaxanthin and(9-Z)-zeaxanthin, were purified from the green alga Chlorella ellipsoidea, in which(all-E)-lutein and(9-Z)-zeaxanthin had potent α-glucosidase inhibitory activity. IC_(50) values of(all-E)-lutein and(9-Z)-zeaxanthin were 70 and 53.5 μmol L~(-1) against Saccharomyces cerevisiae α-glucosidase, respectively, with non-competitive inhibition. In addition, IC_(50) values of(9-Z)-zeaxanthin against Bacillus stearothermophilus and rat-intestinal α-glucosidase were 805.1 and 671.2 μmol L~(-1), respectively. The K_i values of(all-E)-lutein and(9-Z)-zeaxanthin against S. cerevisiae α-glucosidase were 78.1 and 16.5 μmol L~(-1), respectively. Therefore, C. ellipsoidea carotenoids might be utilized as a novel candidate to prevent type-2 diabetes mellitus related disorders in food and medical industry.     

Meso-Cenozoic basin evolution in northern Korean Peninsula

In the Korean Peninsula the Meso-Cenozoic basins were mainly formed due to fault block and block movement. The Mesozoic fracture structures correspond basically to modem large rivers in direction. Such faults were usually developed to rift and formed lake-type tectonic basin, such as the Amrokgang-, Taedonggang-, Ryesonggang-, Hochongang-, Jangphari-, Susongchon-, Pujon-, and Nampho basins. The Mesozoic strata are considered to be divided into the Lower Jurassic Taedong System, Upper Jurassic Jasong System, Upper Jurassic-early Lower Cretaceous Taebo System, and the Upper Cretaceous-Paleocene （ Chonjaebong, Hongwon, Jaedok Series）. The Cenozoic block movement succeeded the Mesozoic fault block movement. The Kilju-Myongchon Graben and Tumangang Basin, etc, are the basins related to the fault zones developed from the Oligocene to Miocene. In addition, the Tertiary basins were formed in many areas in the Miocene （e. g. Sinhung, Oro, Hamhung, Yonghung, Anbyon, Cholwon, etc）. The Cenozoic sedimentation occurred mainly from the late Oligocene to Miocene. The Kilju-Myongchon Graben was the fore deep connected to the sea and the basins inclined in the Chugaryong Fault Zone are intramountain basins. Therefore, coal-beating beds and clastic rocks in the intramountain basins and rare marine strata and terrigenous clastic rocks are main sedimentary sequences in the Cenozoic.     

朝鲜半岛北部定州与铁山稀土矿相关碱性岩和花岗岩的岩石学和SIMS锆石U-Pb年代学特征研究

朝鲜半岛北侧的狼林地块是中朝克拉通的重要组成部分,狼林地块具有与辽南地块以及辽吉活动带类似的早前寒武纪岩石组成、变质和变形特征。我们在分布有稀土矿的朝鲜定州-铁山一带(狼林地块西北部),采集了与稀土矿密切相关的碱性岩(粗粒正长岩和萤石化霓辉正长岩)和花岗岩(似斑状花岗岩)样品。岩石样品的岩相学观察表明,定州与铁山地区的碱性岩和花岗岩并不显示明显的岩浆期之后的热液蚀变特征。SIMS锆石U-Pb定年结果显示粗粒正长岩的岩浆结晶年龄为1865±6Ma,萤石化霓辉正长岩的岩浆结晶年龄为1868±8Ma,铁山地区的四件似斑状花岗岩的年龄结果分别为1871±13 Ma、1866±8 Ma、1872±6 Ma和1873±7 Ma,这些年龄值一方面代表了岩浆活动时代,另一方面可能也代表了朝鲜定州和铁山稀土矿的成矿时代。狼林地块的这些碱性岩与花岗岩的时代与华北克拉通辽吉活动带以及狼林地块其它地区的高级变质作用同期,并且在辽南地块,也有类似碱性岩的报道。综合现有的证据表明,辽吉活动带、辽南地块以及狼林地块在古元古代可能属于同一个大型构造带,并且这个构造带(或者构造带的一部分)当时处于伸展的构造背景。通过全面对比野外观测结果、岩石的岩相结构、岩浆结晶时代可知,朝鲜定州和铁山一带的稀土矿与中朝克拉通的世界级稀土矿——白云鄂博,在岩石组合、稀土矿物组成、岩石蚀变特征、成矿时代等方面存在较大的区别。关于这一稀土矿的具体稀土矿物组成、矿床成因以及储量等众多问题,未来还需要进行大量的工作。     

2002年3月21-22日影响韩国的沙尘天气分析

利用气象卫星、天气形势场和NCEP/NCAR再分析资料,分析了2002年3月21-22日影响韩国沙尘天气的原因. 结果表明:影响韩国沙尘天气的沙尘主要源地是蒙古国和中国内蒙古地区.沙尘天气发生在地面冷锋后部,高压伸展的前面;19日和20日沙尘暴发生后,沙尘沿着西北风输送,21日早晨影响韩国;PM10最高值达到 2 778.2 μg/m3,由于西北风较强,沙尘暴发生后很快影响到韩国,但在韩国持续的时间较短.     

Seasonal Prediction of Monthly Precipitation in China Using Large-Scale Climate Indices

In this study, seasonal predictions were applied to precipitation in China on a monthly basis based on a multivariate linear regression with an adaptive choice of predictors drawn from regularly updated climate indices with a two to twelve month lead time.A leave-one-out cross validation was applied to obtain hindcast skill at a 1% significance level.The skill of forecast models at a monthly scale and their significance levels were evaluated using Anomaly Correlation Coefficients(ACC) and Coefficients Of De...     

三种云导风资料及其对台风数值预报影响试验的比较分析

由于在海面上缺乏重要的常规观测资料,因而云导风成为研究西太平洋台风一种不可缺少的重要资料。为了对“南京信息工程大学”开发的云导风系统(CWIS)进行质量评价及其对台风研究的贡献,选取了三种云导风资料进行综合对比。通过对比CWIS导出FY2C云迹风数据、中国气象局国家卫星中心(NSMC)导出FY2C云迹风数据和日本气象卫星中心（JMSC）的MTSAT云导风数据,采用逐点比较法分析了不同资料的精度与误差。所得结果发现：CWIS的风速与JMSC风速、NSMC的风向与JMSC风向分别均有较好的一致性。使用三重制约法获得了三种云导风资料的误差信息,风速误差标准差以JMSC最小、NSMC最大;风向误差标准差以JMSC最小、CWIS最大。云导风资料在中尺度对流云带和高空急流云带上,NSMC云导风风速大于CWIS、JMSC;而在台风云系上三种云导风资料没有特别的差异。根据以上比较的三种云导风资料的结果,进行了云导风资料对台风路径数值预报的影响的初步试验。结果表明：加入云导风资料模拟后得到的台风移动路径与实况总体上比较接近,不同的资料导出不同的结果,台风中心位置误差减小到23%~74%。     

朝鲜半岛咸北地区晚二叠世基性火山岩的地球化学特征:岩石成因与地质意义

晚古生代火山作用既是探究朝鲜半岛北部大地构造归属的基本要素,又是认识东北亚大陆两大构造域转折之际地球动力学过程的关键窗口。针对咸北地区会宁基性火山岩开展的离子探针锆石U-Pb年代学和地球化学研究表明,其喷发时代为晚二叠世(257±3Ma);主要岩石类型包括玄武安山岩和安山岩,其Si O2含量介于51.9%~55.3%,Mg#变化于40~58,属于钙碱性系列;岩石富集大离子亲石元素、亏损高场强元素(如Nb,Ta,Ti),并具有高正的锆石εH f(t)(+10~+16)值。元素-同位素地球化学示踪指示该基性火山岩的岩浆源区为俯冲沉积物熔体交代而形成的不均一岩石圈地幔,其部分熔融则可能归因于俯冲后的板内伸展背景。会宁基性火山岩不仅为判定咸北地块属于中亚造山带在朝鲜半岛的东延部分提供了岩石学证据,而且与中国相邻地块上的同期岩浆事件一道,构成见证古亚洲洋东段沿西拉木伦-长春-延边一线断裂带最终闭合的空间标记。