南方比湿特征及其与暴雨的关系     

包慧濛  肖安  李葳  等. 《气象与环境科学》2021,44(2):33-42

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荷载对钻孔应变测值影响的实验及力学解析   总被引：1，自引：0，他引：1  

胡卫建  张俊山  谢智  王志敏  李安印  冯建民  刘丽君 《地震》2002,22(3):95-104

介绍了弦频钻孔应变仪和体积式应变仪二次地表荷载试验的结果。根据弹性力学的理论和方法,对钻孔地壳应变测量及荷载试验的力学模型、边界条件等予以简化,使得经典的集中力作用于半无限弹性体表面的布辛奈斯克(Boussinesq)解,可有条件地运用于钻孔应变测量中地表荷载变化问题的定量分析研究。所给出的实验方法、研究思路及计算方法等,对定量研究钻孔应变测量中的荷载干扰、研究岩石力学性质、制定台站钻孔应变观测技术标准及观测规范等具有一定意义。  相似文献   

甲壳胺对褐藻胶胶液的絮凝作用及其在漂浮工艺中的应用研究   总被引：1，自引：0，他引：1  

安丰欣  王长云 《海洋湖沼通报》1998,(4):43-47

研究了甲壳胺作为絮凝剂对褐藻胶胶液的絮凝作用及漂浮效果。结果表明,甲壳胺对褐藻胶胶液具有较强的絮凝作用,其中,１０ｐｐｍ甲壳胺用量的漂浮效果较好,可大大缩短漂浮时间,对清胶液的透光率,粘度和胶收率均有不同程度的提高。  相似文献   

2004年6月江西降水特少成因分析   总被引：1，自引：1，他引：0  

许爱华  张超美  肖安 《气象与减灾研究》2005,28(1):15-17

2004年6月全省月平均雨量之少,为江西1959年以来第二位。时这样1个异常的气候事件,分析了气候背景、中高纬度环流和副热带高压变化特征;同时,时6月西太平洋热带气旋活动与巷省降水的关系进行了普查和分析。分析结果表明,造成我省降水特少的原因主要有3个：一是2004年我省处少雨的大周期中;二是西风带没有稳定的阻塞形势建立,副高偏东偏北,中、西太平洋时流活跃,热带气旋活动频繁：三是孟加拉湾到华南、江南中东部地区对流受到抑制。  相似文献   

初论生物成因的洞穴叠层石的形成条件   总被引：8，自引：0，他引：8  

戎昆方  李景阳  安裕国 《中国岩溶》1998,17(3):285-290

自提出岩溶洞穴石灰华沉积物中的生物成因及洞穴叠层石的存在以来,引起了岩溶洞穴学家的兴趣和关注。本文从沉积岩石学的角度,用生物成因观点,对岩溶洞穴叠层石的形成条件进行分类和论述。将其基本条件划分为物质条件(即内在因素)和环境条件(即外在因素) ,论述了它们在洞穴叠层石形成过程中的地位和作用。   相似文献   

基于弹簧—阻尼理论的海上变电站动力特性研究     

刘兵  陶安  郝俊飞  杨敏  任绅铖 《海洋工程》2024,(2):93-104

近年来,随着海上风电的迅速发展,海上变电站的建设也逐渐兴起。然而,错综复杂、瞬息万变的海洋环境对变电站的安全性和稳定性提出了严峻的挑战,因此有必要加强对变电站分析和研究的重视。为了提高变电站数值模型分析的效率,研究以海上风电场变电站为中心,采用ABAQUS建立了实体土有限元模型和基于弹簧—阻尼理论的有限元模型,以模拟桩土相互作用。随后进行了模态分析、风浪流响应分析和地震响应分析研究。研究结果表明：使用两种模型进行模态分析得出的振型非常相似,频率误差小于5%。此外,在承受风和波流荷载时,两种模型得出的变电站结构响应具有显著的一致性。在地震荷载作用下,两个模型中样本点位移时程曲线的相位频率与测量数据非常接近。值得注意的是,基于弹簧—阻尼理论的模型计算出的振幅与地震波测量数据更为接近。此外,弹簧—阻尼理论方法还大大提高了计算效率。  相似文献   

Parameter identification for on‐line model updating in hybrid simulations using a gradient‐based method          下载免费PDF全文

Ming‐Chieh Chuang  Shang‐Hsien Hsieh  Keh‐Chyuan Tsai  Chao‐Hsien Li  Kung‐Juin Wang  An‐Chien Wu 《地震工程与结构动力学》2018,47(2):269-293

To improve the efficiency of model fitting, parameter identification techniques have been actively investigated. Recently, the applications of parameter identification migrated from off‐line model fitting to on‐line model updating. The objective of this study is to develop a gradient‐based method for model updating to advance hybrid simulation also called hybrid test. A novel modification of the proposed method, which can reduce the number of design variables to improve the identification efficiency, is illustrated in detail. To investigate the model updating, simulated hybrid tests were conducted with a 5‐story steel frame equipped with buckling‐restrained braces (BRBs) utilized in the shaking table tests conducted in E‐Defense in Japan in 2009. The calibrated analytical model that was verified with the test results can serve as the reference model. In the simulated hybrid tests, the physical BRB substructure is numerically simulated by utilizing a truss element with the 2‐surface model identical to the part of the reference model. Such numerical verification allows simulation of measurement errors for investigation on the performance of the proposed method. Moreover, the feasibility of sharing the identified parameter values, which were obtained from the physical substructure responses, with the relevant numerical models is also verified with the artificial component responses derived from the physical experiments.  相似文献   

亚高山湖泊天才湖周边土壤腐殖酸的光降解研究     

安世林  罗春燕  陈煜  杜瑛珣 《湖泊科学》2022,34(2):553-568

溶解性有机质(DOM)是湖泊生态系统的物质循环和能量流动的基础.典型亚高山湖泊DOM的主要来源为流域土壤腐殖酸(外源DOM),其具有较强的光吸收特性,光降解是其重要的转化过程,从而改变碳、氮、磷等物质的存在形式.在气候变暖的背景下,亚高山湖泊中DOM的浓度、pH、溶解氧及太阳辐射都可能发生变化;但这些环境变化对亚高山湖...  相似文献   

基于WWW的湖泊信息系统     

赵安 《湖泊科学》1999,11(2):189-192

本文阐述了中国湖泊数据库原有基础与特点,结合近年来信息技术和地理信息系统的进展,提出了英特网时代中国湖泊信息系统的新概念,探讨以万维网为平台的湖泊信息系统组织模型与客户机－服务器为基础的服务模型,并解决了基于万维网的湖泊信息系统的若干关键技术问题。  相似文献   

Gravity and magnetic field characteristics and hydrocarbon prospects of the Tobago Basin          下载免费PDF全文

Bingqiang Yuan  Lijun Song  Li Han  Shaole An  Chunguan Zhang 《Geophysical Prospecting》2018,66(8):1586-1601

The Tobago Basin, which is located offshore northern Venezuela with a southern margin close to Trinidad and Tobago, has an area of approximately 59,600 km². The Tobago Basin has relatively favourable hydrocarbon prospects, and to date, exploration work has mainly concentrated on small areas of the southwestern portion of the basin. To conduct a comprehensive study of the structural framework of the basin and the characteristics of the basement in order to identify prospective zones for hydrocarbon exploration, shipborne‐measured and satellite‐measured gravity data, shipborne‐measured magnetic data, and aeromagnetic survey data were analysed. A regularisation filtering method was used to separate and obtain regional and residual gravity and magnetic anomalies. Directional gradients of gravity and magnetic anomalies and the total horizontal gradient and vertical second derivative of gravity anomalies were employed to extract information about fault structures. Regression analysis methods were used to determine the basement depth. The geological significance of the gravity and magnetic fields was examined, the structural framework of the basin was assessed, the basement depth was estimated, and favourable hydrocarbon exploration prospects within the basin were identified. The results show that the Tobago Basin contains complex structures consisting mainly of two groups of faults trending in northeasterly and northwesterly directions and that the major northeasterly trending faults control the main structural configuration and depositional system within the basin. The basement of the Tobago Basin has deep rises and falls. It can be divided into the following four secondary tectonic units: the western sub‐basin, the central uplift area, the southern sub‐basin, and the northeastern sub‐basin. The central uplift area and northeastern sub‐basin are most likely to have developed hydrocarbon accumulations and should be targeted for further exploration.  相似文献