海温对春季冷暖环流的遥相关及影响我国南方春温的过程

利用1950～1998年太平洋海温资料进行分析,得出太平洋海温对春季冷暖环流的遥相关,并得出海温影响大气冷暖环流的过程,进一步分析得到太平洋海温影响亚欧中高纬环流及西太平洋副高的时间.从而得出太平洋海温影响我国南方春温的过程为:前2年10月到前一年3月赤道东太平洋海温持续暖(冷)→前1年3月西太平洋副高持续强(弱)→春...     

隆林县2009—2010年秋冬春连旱成因分析与评估

分析2009～2010年隆林秋冬春连旱的直接原因和深层次原因,并利用降水距平百分率和相对湿润度指数对气象干旱等级进行评估,为政府和有关部门抗旱救灾和灾害评估提供参考。     

新10号泉硫化物前兆异常特征分析

运用mapsis软件前兆异常分析中的差分、从属函数等计算方法对新10号泉硫化物测值进行异常识别。结果表明：（1）差分和从属函数异常以高值异常为主;（2）差分异常对应近场MS≥5地震对应率为100%（6/6）,对远场MS≥7地震对应率为66.7%（4/6）;（3）差分和从属函数异常最大量对近场MS≥5地震的震级和震中距相关性不明显;（4）差分和从属函数异常有一定同步性。     

固原硝口温泉CO2气体异常与映震效应

对2008年固原硝口CO2气体测值异常和整体变化的不稳定因素进行分析,从气温、降雨、仪器和人为因素等方面排除干扰,认为2008年汶川8.0级地震前后出现的短期异常真实可靠.对距今18年的观测资料进行异常统计,发现18次异常中有6次较好对应周围Ms≥4.9地震.结果发现,该测项短期异常具有短期趋势性下降一转折上升和多次单...     

双排弹性桩隔振屏障对平面SH波的多重散射

提出了一种新的求解任意排列、任意半径的弹性桩对平面SH波的多重散射的理论方法,以解决以往假设单重散射的计算方法中不考虑桩列作为整体屏障从而忽略桩间相互干涉关系的不足,并且可用于分析多排弹性桩对平面SH波的散射性状。在数值计算分析中讨论了散射重数,排间距,桩土剪切模量比,桩数等对双排弹性桩屏障隔离效果的影响,从而对实际工程中利用排桩进行振动污染的治理和屏障隔振设计提出了重要的理论依据。     

Rosenbrock‐based algorithms and subcycling strategies for real‐time nonlinear substructure testing

In this paper, Rosenbrock‐based algorithms originally developed for real‐time testing of linear systems with dynamic substructuring are extended for use on nonlinear systems. With this objective in mind and for minimal overhead, both two‐ and three‐stages linearly implicit real‐time compatible algorithms were endowed with the Jacobian matrices requiring only one evaluation at the beginning of each time step. Moreover, these algorithms were improved with subcycling strategies. In detail, the paper briefly introduces Rosenbrock‐based L‐Stable Real‐Time (LSRT) algorithms together with linearly implicit and explicit structural integrators, which are now commonly used to perform real‐time tests. Then, the LSRT algorithms are analysed in terms of linearized stability with reference to an emulated spring pendulum, which was chosen as a nonlinear test problem, because it is able to exhibit a large and relatively slow nonlinear circular motion coupled to an axial motion that can be set to be stiff. The accuracy analysis on this system was performed for all the algorithms described. Following this, a coupled spring‐pendulum example typical of real‐time testing is analysed with respect to both stability and accuracy issues. Finally, the results of representative numerical simulations and real‐time substructure tests, considering nonlinearities both in the numerical and the physical substructure, are explored. These tests were used to demonstrate how the LSRT algorithms can be used for substructuring tests with strongly nonlinear components. Copyright © 2010 John Wiley & Sons, Ltd.     

贵州荔波岩溶峰丛区表层岩溶泉对大气降雨的响应及其指示意义

以贵州荔波岩溶峰丛区表层岩溶泉为研究对象,采集同期大气降雨和泉水样品,根据它们的δ18O值和δD值以及水量特征,分析植被-土壤-表层岩溶带的调蓄功能.根据表层岩溶泉对降雨的响应特征,将植被-土壤-表层岩溶带分为慢速流域和快速流域,两域之间存在一定的水力联系.卷积积分理论的余弦模型计算结果表明,补给水体经慢速流域调蓄后,...     

人类活动对柳林泉域水文过程影响研究

20世纪50年代以后,柳林泉流量日益减少,人类活动成为其衰减的主要原因。通过分阶段应用灰色系统模型,定量地描述人类活动对柳林泉水文过程的影响。第一阶段(1957~1973年),柳林泉水流量只受自然条件的影响,第二阶段(1974~2009年)柳林泉水流量受自然条件和人类活动的双重影响。运用灰色关联分析和GM时滞模型,通过比较分析得到人类活动对柳林泉水文过程的影响。结果显示:人类活动导致泉水流量相对于降水量的时间滞后由0年增长到4年,即地下水压力波在传播过程中受到人类活动的干扰,强度被削弱,传播速度变缓。降水量对泉水流量的灰作用系数由第一阶段的1.127 2×10-2下降到了第二阶段的7.75×10-3,说明由于人类活动使降水量对泉水流量的补给强度减弱。     

高黎贡山南段主要热泉水化学同位素特征研究

笔者应用水化学同位素技术,对高黎山南段主要热泉成因及循环特征进行了研究,取得了一些重要认识。研究区热泉水为低矿化、碱性、Na-HCO3型水;热泉水主要为大气降水起源,循环速率较快,水岩作用不充分,径流环境多处于相对开放的氧化环境之中。以黄草坝泉、三官泉特征比较明显;地下水补给区主要位于泉点附近高程在1800 m的区域范围之内,为附近区域大气降水补给形成;存在浅层、深层两种混合作用形式,黄草坝泉、三官泉现代大气降水混合比在90%以上;热泉热储温度为100～200℃,循环深度在2000～4000 m。     

Applicability of sediment transport models to evaluate medium term evolution of tidal inlet systems

This paper derives local formulae to estimate bed roughness and suspended transport and present a method to calculate net sediment transport at tidal inlet systems, combining field data and a range of well established empirical formulations. To accomplish this, measurements spanning a spring-tidal cycle of mean water levels, waves, near-bed flow turbulence and bed forms were obtained from the Ancão Inlet, Ria Formosa lagoon system, Portugal. High-resolution hydrodynamic data were gathered using acoustic equipments and by measuring sediment properties (grain-size diameter and bed form dimensions) under fair-weather conditions. The results compared favourably with available direct and indirect field observations of sediment transport rates. The approach appears to be robust and widely applicable and so can be applied to the same conditions in any tidal inlet system. This is of particular importance when attempting to understand sediment transport at inlet mouths, and has practical applications in a range of coastal engineering and coastal management areas concerned with navigation safety, coastal erosion, ecosystem health and water quality. The study discusses the applicability of the method on evaluating system flushing capacity, giving important insights on multiple inlet evolution, particularly with regard to their persistence through time. The methodological framework can be applied to assess the long-term stability of single- and multiple-inlet systems, provided that estimates of sediment storage at ebb-tidal deltas are available and sediment transport estimates during storm events are statistically considered.