关于计算空间曲线预应力筋张拉伸长值的探讨

把肇源松花江大桥划分成57个受力段,利用“桥梁博士V2．8”系统进行计算,采用简化法计算了曲线预应力筋张拉伸长值、张拉控制应力和张拉控制力。     

Late Cenozoic Normal Faulting on the Western Side of Wenquan Graben, Central Qianghai-Xizang(Tibet) Plateau

INTRODUCTION ThesustainedcollisionoftheIndiaplateintotheEurasiaplatesince50MaBPgaverisetotheintenseCenozoictectonicdeformationandupliftingofmountainsintheQinghai Xizang(Tibet)Plateauanditsvicinityandhadafar reachingimpactonthegeomorphicpatternsandenvironm…     

Measuring similarity between geospatial lifelines in studies of environmental health

Many epidemiological studies involve analysis of clusters of diseases to infer locations of environmental hazards that could be responsible for the disease. This approach is however only suitable for sedentary populations or diseases with small latency periods. For migratory populations and diseases with long latency periods, people may change their residential location between time of exposure and onset of ill health. For such situations, clusters are diffused and diluted by in- and out-migration and may become very difficult to detect. One way to address the problem of diffused clusters is to include in analyses not only current residential locations, but all past locations at which cases might have been exposed to environmental hazardous. In this paper, we assume that a persons residential history provides such information and represent it through a discrete geospatial lifeline data model. Clusters of similar geospatial lifelines represent individuals who have similar residential histories—and therefore represent people who are more likely to have had similar environmental exposure histories. We therefore introduce a lifeline distance (dissimilarity) measure to detect clusters of cases, providing a basis for revealing possible regions in space-time where environmental hazards might have existed in the past. The ability of the measure to distinguish cases from controls is tested using two sets of synthetically generated cases and controls. Results indicate that the measure is able to consistently distinguish between populations of cases and controls with statistically significant results. The lifeline distance measure consistently outperforms another measure which uses only the distance between subjects residences at time of diagnosis. However, the advantages of using the entire residential history are only partly realized, since the ability to distinguish between cases and controls is only moderately better for the lifeline distance function. Future work is needed to investigate modifications to the inter-lifeline distance measure in order to enhance the potential of this approach to detect locations of environmental hazards over the lifespan.This project is supported by grant number 1 R01 ES09816-01 from the National Institute of Environmental Health Sciences, NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS or NIH. We wish to thank Peter Rogerson for helpful discussions of the migration models, and the anonymous reviewers for pointing out areas where the paper could be improved.     

Tectonosedimentary Evolution of the Cheb Basin (NW Bohemia,Czech Republic) between Late Oligocene and Pliocene: A Preliminary Note

A working model of tectono-sedimentary evolution is proposed for the Cheb Basin, a polyhistory sedimentary basin formed between the late Oligocene and Pliocene by reactivation of basement fracture systems in the northwestern part of the Bohemian Massif. The basin is located at the intersection of the Ohe (Eger) Graben structural domain, characterized by dominance of NE-striking graben systems in present-day geology, and the NW-striking Cheb-Domalice Graben, a major strike-slip – dominated structure in Western Bohemia. The first significant depositional episode in the Cheb Basin coincides with the deposition of late Oligocene-Miocene clastics in the whole extensional system of the Ohe Graben, controlled by E-W – trending depocenters. The main structural feature of the Cheb Basin region at that time was a palaeohigh caused by a NW- trending accommodation zone separating minor E-W – trending depocentres. The second, late Pliocene, episode of sedimentation occurred under a very different kinematic regime than the Oligo-Miocene rift basin evolution. During this time, the present-day structure of the Cheb Basin and the Cheb-Domalice Graben formed as a consequence of sinistral displacement on the Mariánské Lázn Fault Zone. Reactivation of this strike-slip fault zone led to the formation of a horsetail splay of oblique-extensional faults at the northern termination of the Mariánské Lázn Fault Zone, which contained the present-day Cheb Basin.     

用波函数展开法求解界面圆孔的SH波散射问题

研究了ＳＨ波绕界面圆孔散射的波函数展开理论。由入射,反射和透射波组成的自由波场与孔的散射场叠加成总波场。将定义于两个半平面的散射场按一定方式延拓到全平面。通过Ｈａｎｋｅｌ－Ｆｏｕｒｉｅｒ型积分来满足界面与孔缘处的边界条件,得到了确定特定系数的封闭代数方程组。给出了具体算例,计算了孔缘处的动应力系数分布。     

Research, Extension and Industry – Working Together Can Achieve Results

Over recent decades, research has been directed to assessing the impacts of land uses on valuable natural assets, such as the Great Barrier Reef. Land managers in adjacent areas are expected to adopt practices to minimize any adverse affects on downstream environments. Conversely, researchers are being pressed to provide answers to the problems. In response, researchers and environmental managers are bombarding land managers with information regarding the potential environmental implications of their practices. Is this an effective mode to achieve on-ground change?

Collaboration between all groups – research, industry and extension – may be more effective in developing and implementing practical solutions to these more complex issues. A change from the research and extension models currently used may be needed to achieve positive resource management outcomes.

Research, development and extension initiatives underway in the Australian sugar industry to improve farm practice and reduce the potential for adverse impacts on downstream environments are discussed. Case studies provide some insights into how science and extension skills work best together and how an industry group can respond to a community concern.     

秦岭造山带及相邻地块元古代基性岩墙群研究综述及相关问题探讨

基性岩墙群是重建古陆块聚合、伸展乃至裂解的关键标志之一。通过对秦岭造山带及相邻的华北地块、扬子地块元古代基性岩墙群的时空对比综 合分析表明,华北地块区发育2300Ma±和1700～1200Ma的两期基性岩墙群,分别代表了新太 古代和古元古代华北古陆块的聚合、伸展过程;扬子地块区发育800～620Ma的基性岩墙群, 反映了新元古代扬子古陆块的聚合、伸展过程。认为前震旦纪华北地块和扬子地块可能是独 立古陆块或不同古陆块的组成部分。晋宁造山作用(1100～850Ma)和澄江伸展、裂解作用(800Ma±)是可与新元古代Rodinia超大陆聚合、裂解过程进行对比、研究的重要时期。     

藏南聂拉木地区上三叠统与侏罗系中伸展不整合以及各组地层的厘定

晚三叠世及侏罗纪是特提斯大洋形成和扩张的时期。藏南聂拉木地区的相应地层中普遍存在裂陷盆地沉积及众多的伸展不整合。根据这些不整合面之上的“超越下伏地层不正常的化石混积事件”,判断早侏罗世赫唐早期和中侏罗世巴通期裂陷幅度分别为大于 1 60 0 m和大于80 0 m。作者根据这些不整合面以及遵循地层命名的“优先法则”,对各个组的地层划分与名称进行了厘定。     

秦岭构造带的东延兼述其高压变质带的形成深度与机制

在介绍郯庐断裂东西两侧ＥＷ向构造基本特征的同时,从将秦岭带理解为高级协和函数和边界条件差异及构造复合等方面具体探讨了下述问题：为什么秦岭东延后构造形迹显得宽散零落？ＮＥ向的苏鲁变质岩构造带何以也成为秦岭构造带的成份？重塑了“老淮阳弧构造”,指出在郯庐断裂东侧,古老的秦岭带发生北移,中新生代秦岭带又在原水的纬度上产生,其构造形迹北抵海州湾两侧,南达杭州湾附近。还探讨了该区高压变质带的形成深度和动力学     

PETROLOGY AND AGE OF THE KINNAR KAILAS GRANITE:EVIDENCES FOR AN ORDOVICIAN POST-OROGENIC EXTENSION IN THE HIGHER HIMALAYAN CRYSTALLINE, SUTLEJ, INDIA.

PETROLOGY AND AGE OF THE KINNAR KAILAS GRANITE:EVIDENCES FOR AN ORDOVICIAN POST-OROGENIC EXTENSION IN THE HIGHER HIMALAYAN CRYSTALLINE, SUTLEJ, INDIA