通辽市一次久旱转雨天气过程诊断分析

应用常规天气资料、卫星云图及多普勒雷达产品资料,针对2009年4月18日夜间至21日白天通辽地区出现的一次久旱转雨天气过程,通过动力诊断分析和物理量诊断方法阐述了此次过程的环流成因,利用多普勒雷达反射率因子、径向速度、风廓线及回波高度产品,揭示了这次过程天气系统的回波特征。结果表明:这次过程分别是由低层暖湿切变及短波槽不断分裂南下加强后,与地面倒槽配合形成的低涡影响造成的。     

不同支护条件下锚杆支护作用的模型试验研究与数值分析

以重庆至长沙公路共和隧道为研究对象,研制出相似模型材料和配套试验设备,进行不同长度锚杆支护条件下的隧道超载试验。采用应变测量技术,测量两种不同长度锚杆支护工况下的隧道关键部位的应变值,据此分析围岩体在锚杆支护后的应力变化规律。通过模型材料室内试验,获取岩体相关计算参数,采用与模型试验相同的边界条件进行相应工况的有限元数值模拟,研究围岩体的变形量、应力场和锚杆轴力因锚杆长度不同而产生的变化。结果表明,模型试验和数值模拟反映围岩体应力和锚杆轴力因锚杆长度的不同而产生的变化是一致的。     

石家庄夏季用电量对天气的响应及其预测模型

从石家庄市2005～2007年每年6～8月的逐日用电量资料中分离出随气象因子变化的气象电量,分有、无降水日分别计算了气象电量与同期气象资料中关键气象要素的相关系数,着重分析了气象电量随气温、湿度、降水的变化规律.结果表明:石家庄夏季气象电量与气温呈显著性正相关,而与相对湿度仅在有降水日为显著负相关;计算了用电量逐日变化值与气象要素日变化值之间的相关系数,发现要素差值之间存在着很好的相关性.在统计分析的基础上,借助Origin7.5软件,分有、无降水日建立了综合气象因子影响下气象电量及用电量逐日变化的多元回归预测模型,回归统计及方差分析表明:预测方程均通过了α=0.0005的F检验,复相关高于单相关,拟合率较高,能为电力部门合理调度提供参考.     

缓倾角层理各向异性岩体隧道稳定性的物理模型试验研究

层状岩体的广泛分布是地下工程无法回避的现实。以渝湘高速公路共和隧道为工程背景,采用自行研制的弹脆性模型相似材料,制作出层状岩体隧道模型。采用大型真三轴岩土工程模型试验机进行加载试验,采用围岩应变监测、洞室内窥摄影、试件破坏形态的研究与分析,从而对缓倾角层理岩体中隧道的二次应力分布特征及破坏机制进行研究。试验中还通过超载系数,提供了一个安全储备的定量评估指标。试验的破坏特征与隧道实际破坏一致,说明了模型试验的正确性,同时也为顺层偏压隧道的加固机制研究及加固设计提供了试验基础。     

HUMAN SPACEFLIGHT: ACHIEVEMENTS, BENEFITS AND FUTURE OPPORTUNITIES FROM A EUROPEAN PERSPECTIVE

The past achievements, benefits and future opportunities of human spaceflight are discussed from a European perspective. Earlier work performed on the Skylab, Salyut, Shuttle, Spacelab, and Mir orbital facilities is reviewed, together with the prospects for new research on the International Space Station (ISS). Major scientific benefits are expected from the ISS in the areas of life science research (including human physiology and medicine) physical sciences, and fundamental physics.     

Numerical Simulation of Dynamic Response of A Net Cage for Flatfish in Waves简

A numerical model of flatfish cage is built based on the lumped mass method and the principle of rigid body kinematics. To validate the numerical model, a series of physical model tests are conducted in the wave flume. The numerical results correspond well with the data sets from physical model test. The effect of weight of bottom frame, height of fish net and net shape on motion responses of fish cage and tension force on mooring lines is then analyzed. The results indicate that the vertical displacements of float collar and bottom frame decrease with the increase in the weight of bottom frame; the maximum tension force on mooring lines increases with the increasing weight of bottom frame. The inclination angles of float collar and bottom frame decrease with the increasing net height; the maximum tension force increases obviously with the increase of net height.     

强震作用下层状岩质斜坡破坏的大型振动台试验研究

以“5.12”汶川地震背景为基础,对不同岩性组合水平层状岩质边坡进行了大型振动台模型试验研究.文中介绍了振动台试验过程,通过对试验现象的观察处理分析,考察了边坡的破坏现象特征、变形破坏模式.实验结果表明,地震力作用下边坡的变形破坏程度、特征以及稳定性不仅与地震波的类型、加载方向、频率、振幅有关,同时还受边坡的岩体性质、...     

基于二元水循环的河流生态需水水量与水质综合评价方法——以辽河流域为例

In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed,and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river re-quirements,the efficiency of water resource usage,the consumption coefficient,and the concentration of waste water elimination,the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed,and the criteria for environmental flows of river requirements are established,and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized. Taking the Liaohe River as a model,the environmental flows of river requirements for Xiliao River,Dongliao River,mainstream Liaohe River,Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated,each taking up 39.3%,63.0%,43.9%,43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow,the results show that: except Xiliao River is "median",the rest are all upon "good",the Dongliao River is even "very good". The corresponding results in dualistic water cycle are that,the proportion of natural flows for each river is 57.5%,74.1%,60.8%,60.3% and 60.4%; while the combined evaluation results show that: considering "quantity",except Xiliao River,the rest rivers can all achieve the "quantity" criteria of the en-vironmental flows of river requirements,but if considering the aspect of "quality",only Dongliao River can reach the "quality" standard. By water quantity-quality combined evalua-tion method,only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem de-mands.     

2013年广西一次前汛期暴雨过程分析

利用地面观测资料、探空资料和卫星观测资料对2013年4月29日至5月1日广西东部地区出现的一次暴雨天气过程进行分析,结果表明：（1）本次强降雨过程前期具有典型的暖区暴雨天气过程,主要受高原槽、低层急流系统影响,低层风向辐合高层辐散的配置触发了暴雨天气的产生,后期冷空气南下影响,触发强对流云团发展,造成强降雨天气的持续;（2）过程期间涡度场、散度场低层辐合高层辐散配置较好,水汽辐合上升强烈;（3）中尺度雨团在广西东部连续的生成并维持,造成桂东地区大范围的暴雨天气.     

东亚地区气象参数卫星遥感反演理论和方法研究I:ISPRM和SRRM

文中对10a来改进的同步物理反演方法（ISPRM）实践与发展进行了总结。在不违背先验信息和卫星测值之间独立的原则下,所做的改进都是针对这类非适定反演问题的欠定性（under－determinedness）进行的。由适定反演理论知道,正演是反演的基础,又是卫星辐射率测值输入和反演结果输出之间的桥梁。为了获得好的正演,就必须竭尽可能充分利用一切可以使用的先验信息,把非适定反演问题转化成适定的反演问题,从而通过Ridge回归或Bayes反演过程,把先验信息、理论模拟信息和卫星探测信息三者最佳地结合起来,以最大限度减少这类反演问题的欠定性对数值解的影响。