从第22届IUGG大会看地震预测研究

1999年 7月 19～ 3 0日 ,第 2 2届 IUGG大会在英国伯明翰大学举行。从提交的论文中可以看出 ,有关地震预测和地震灾害的研究仍是地学界关注的热点问题。文章介绍了这次大会反映出的有关地震预测研究的情况。     

滇西羊拉铜矿床稀土元素地球化学研究

滇西羊拉铜矿是近年来发现的大型铜矿床。本文系统研究了该矿床不同岩石、矿石、矿石矿物及脉石矿物的稀土元素地球化学特征,研究表明：矿区花岗闪长岩具有与壳幔型花岗岩类相似的稀土元素特征;早期形成的块状硫化物矿石及其矿物中稀土元素含量高,富集轻稀土,具有负Ｅｕ异常,与赋矿地层碎屑岩、硅质岩的稀土元素球粒陨石标准化配分相似,反映其成矿物质来源于上地壳;中晚期形成的夕卡岩矿石及破碎带充填、交代型矿石及其矿物中     

Estimating The Dust Particle Size Of Comet Hale–Bopp By Studying The Motion Of The Ejecta On September 10–11, 1996

We report the observation of an outburst of comet Hale–Bopp (C/1995 O1) happened on September 10–11, 1996, carried by the 1.56 m telescope of Shanghai Astronomical Observatory. Two ejecta were found in CCD images during the outburst. According to the positions of ejecta, we discuss the motion of the ejecta considering dust particles are subjected to the gravity and the Solar radiation pressure, and conclude that the mean radii of dust grains in the ejecta were about submicron-sized. So the observed X-ray emission are most likely produced by small size particles scattering the Solar X-ray. This revised version was published online in July 2006 with corrections to the Cover Date.     

南海夏季风暴发过程的低频特征

应用1979～1996年共18a的NOAA卫星OLR资料及NCEP/NCAR再分析850hPa风场资料,分析了夏季南海地区及南海季风暴发过程的某些低频特征。认为北半球夏季南海地区的低频活动较活跃,并且具有明显的年际变化,这种年际变化同南海季风的暴发时间有联系。南海地区的低频振荡在南海季风暴发后增强。通过对18a 及K*的时段叠加合成图的分析,发现南海夏季风的暴发同赤道印度洋低频振荡的东传及西太平洋低频扰动西传有密切联系,南海夏季风暴发期间南海地区将印度洋与西太平洋之间的低频活动联系在一起。     

太阳光谱仪用探测器的研究

观测太阳光谱所使用的探测器,在选型与使用上有其特殊性。结合云南天文台太阳光谱仪,首先建立了太阳光谱仪分光流量的计算机模型,并通过观测实验对该模型进行了检验。利用该模型计算了云南天文台太阳光谱仪各可见光及近红外波段的太阳光谱分光流量,在此基础上,详细讨论了太阳光谱仪用探测器的选型方案,以及观测中的注意要点。     

环境决策支持系统的设计及其在水质管理中的应用

ＥＤＳＳ（Ｅｎｖｉｒｏｎｍｅｎｔａｌ Ｄｅｃｉｓｉｏｎ Ｓｕｐｐｏｒｔ Ｓｙｓｔｅｍ）是一处适用于潮汐河网地区水环境管理和决策的软件系统,其主要功能是协助政府部门进行有效和科学的水环境管理。该系统采用地理信息系统、数据管理系统、模型库管理系统和专家系统等先进技术,将环境数据库、水动力与水质模型库、经济优化技术、环境专家以及环境法规有机地集成在一起。文中首先介绍了ＥＤＳＳ的组织方法、设计特征、实现技     

Effect of nitrogen and phosphorus on the growth of a red tide dinoflagellateScrippsiella trochoidea (Stein) Loeblich III

Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen-or phosphorus-limited batch culture system in laboratory. Growth rates and cellular Chl-a were measured as functions of nitrate and phosphate concentrations. Growth rates were hyperbolic with both nitrate and phosphate concentration and fit the Monod equation. The minimum cell quota of nitrogen and phosphorus and then the optimum N∶P ratio ofS. trochoidea were estimated in this study. Measurement of phosphate concentration in Jiaozhou Bay suggest that phosphorus is the limiting factor ofS. trochoidea growth. Contribution No. 3679 from the Institute of Oceanology, Chinese Academy of Sciences. Project 39790110 supported by NSFC, the study aslo supported by the National Climbing Project B (PDBG-7-2) and partly supported by an MF grant from Hong Kong University of Science and Technology.     

浙江西部梅汛期两次相似落区暴雨过程对比分析

利用浙江省常规气象观测资料、ERA5逐小时再分析资料、FY-4A卫星黑体亮度温度(TBB)资料,对2020年6月3日、6月30日两次暴雨过程进行对比分析。结果表明：(1)6月3日暴雨过程(简称“6·03”过程)发生在季风槽背景下,浙江省500 hPa处于槽前西南气流中,850 hPa为暖切变;而6月30日过程(简称“6.30”过程)发生在东北冷涡背景下,浙江省500 hPa处于冷暖气流交汇中,850 hPa为冷切变。两次过程降水落区相似,均集中在浙西地区,呈东西向带状分布,但“6·30”过程暴雨区范围更广,暴雨中心雨量和过程雨量更大,小时雨强更强,强降水持续时间更长。(2)两次过程均为对流不稳定性降水,但强降水落区发生在急流的不同位置。“6·03”过程为暖切变型暖区暴雨,对流云团“列车效应”显著,降水落区位于急流前方水汽通量强辐合区内,而“6·30”过程梅雨锋为西风辐合型锋生,对流云团为后向传播路径,降水落区位于急流轴附近的水汽通量强辐合区内。700 hPa水汽通量辐合大值区及强度与未来6 h强降水落区、强度相对应,这在梅汛期暴雨预报中有一定参考性。(3)降水类型不同,对应锋生作用不同...     

Centrifuge modelling of ground-borne vibrations induced by railway traffic in underground tunnels

Increased attention has been given to ground-borne vibrations induced by railway vehicles and to the effects of these vibrations as they propagate through the ground into nearby buildings.Various studies,mainly based on numerical methods as well as physical modelling,have been carried out to investigate this problem.To study the dynamic response of tunnels and the surrounding soil due to train-induced vibration loads,a centrifuge te st was conducted with a small-scale model in 1 g and 50 g stres...     

金塘岛北部海域地形变化对水动力环境的影响

浙江舟山金塘岛北部围填海工程使其周边海域的地形产生了较大的变化。本文利用数值模拟方法研究了该围填海工程引起的地形变化对金塘岛周边海域的潮流、余流以及泥沙冲淤的影响。研究结果表明：地形变化对沥港水道影响较大,水道北部入口位置向北移,入口处流速明显增大,涨急流速由0.50 m/s增强为0.92 m/s,增强了84%,落急流速由0.30 m/s增强为0.53 m/s,增强了77%,余流流速由0.05 m/s增强为0.12 m/s,增强了140%;沥港水道中部转角处落急流速减弱;围填海工程新生成的岬角处流速变化也较大,2个岬角凹处形成旋转流场,涨急流速由0.46 m/s减弱至0.14 m/s,减弱了70%,落急流速由0.61 m/s减弱至0.17 m/s,减弱了72%,余流流速由0.55 m/s减弱至0.04 m/s,减弱了93%。金塘岛北部海域泥沙淤积分布与余流变化大小分布一致,表明两者密切相关且均受地形变化影响显著。