浅述次生孔隙的成因

生油岩生成的油气,必须运移到储集层中贮存起来,这样油气才可成藏,而岩层的孔隙度是其储集性好坏的重要标志,次生孔隙在此更是有极重要的意义(因为随着岩层的埋深,成岩作用不断在进行,原生孔隙将减少,次生孔隙将在储油方面扮演重要角色),因此,笔者着重论述次生孔隙的成因及其相关问题。     

日本MW 9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义探讨

为了探讨日本M_W 9.0级大地震前后华北和东北地区现今构造应力作用调整过程与研究意义,对华北和东北地区进行原位现今地应力绝对测量与实时监测、GPS测量,结果表明：日本大地震在山东半岛、华北北部地区和东北地区所诱发同震位移引起的张性效应调整周期分别约为6个月(即调整结束时间大约在2011年9月)、15个月(即调整结束时间大约在2012年6月)和26个月(即调整结束时间大约在2013年5月),张性效应调整周期与同震位移大小成正比。在这种调整过程中,往往表现出区域现今构造应力作用方式和构造应力场转换,并可能伴随重大地质事件(如地震等)的发生。2012年5月28日和29日、6月18日、8月26日及2013年1月11日在唐山及其周围地区分别发生的4.8级、3.2级、4.0级、3.3级和3.0级地震与华北北部地区构造应力作用方式和构造应力场转换有关,而2013年10月31日以来在吉林省松原市发生的地震群应与东北地区构造应力作用方式和构造应力场转换有关,而非一个大地震前的小震群。     

广州珠江西航道,流溪河有机污染特征与感潮作用

珠江西航道和流溪河在广州市区上游，为广州市主要水源区。由于感潮作用，受市区严重污染的水体因涨潮上溯而上游传输。严重影响上游水质。因此，弄清感潮作用对广州水源区水质的影响程度和范围，对水源保护与利用有重要意义。本研究从下游到上游，对水源区底泥中有机物特征进行了分析，结果表明：（１）从上游到上游，受感潮作用影响逐渐减小，污染程度逐渐减轻；（２）水源区有机物特征呈有规律变化。从靠近城市的下游到远离城市的     

Local collective action: Adaptation to coastal erosion in the Monkey River Village,Belize

Successful adaptation to environmental change and variability is closely connected with social groups’ ability to act collectively, but many social-ecological challenges exceed local adaptive capacity which necessitate assistance from governmental institutions. Few studies have investigated how local collective action can be used to enrol external support for adaptation. This paper reduces this research gap by analysing a locally driven adaptation process in response to coastal erosion in Monkey River Village, Belize. Drawing on literature on adaptation and political ecology, we examine the different strategies the local residents have used over time to influence government authorities to support them in curbing the coastal erosion. Our findings show that the local mobilisation generated government support for a temporary sea defence and that collective strategies emerge as a response to threats to a place specific way of life. Our case illustrates that it was essential that the villagers could ally with journalists, researchers and local NGOs to make their claims for protection heard by the government. The paper contributes to adaptation research by arguing that local collective action, seen as contestation over rights to protection from environmental change, can be a means for places and communities not prioritised by formal policies to enrol external support for adaptation. Our study supports and adds to the perspective that attention to formal arrangements such as adaptation policy alone has limited explanatory power to understand collective responses to change.     

Improvement and Application of the Similarity Saltation Model: Wind-Tunnel Experimental Investigation and Numerical Simulation of the Vertical Sand Mass Flux Distribution in the Saltation Layer

Based upon comparisons between published experimental data and simulated results on the vertical sand flux distribution in the saltation layer, Shao’s similarity saltation model has been greatly improved by correcting the average vertical particle lift-off velocity and using a more suitable universal roughness length. By the improved model, the vertical sand flux profile over the bare, dry and loose uniform sandy surface, which is quite representative of real desert surfaces, can be reproduced very well. Meanwhile, the surface transport rate and the characteristic and average saltation heights have been simulated and analyzed in detail, disclosing their relationships with friction velocity, particle size and roughness length, and the possible underlying mechanisms. Besides, the average particle lift-off velocity and the average mean vertical aerodynamic action upon the ascending particle, which determine the saltation process, are explicitly expressed by parameters involved in the similarity model, and their relationships with friction velocity, particle size and roughness length are also described concisely. The corrected average particle lift-off velocity makes it possible to investigate the characteristic particle trajectory, whose initial velocity equals the average lift-off velocity, so as to estimate the average particle against surface impacting velocity and the average aerodynamic action upon the saltation process.     

气候变化适应行动实施框架——宁夏农业案例实践

宁夏是我国生态脆弱区和贫困区之一,以宁夏为例开展农业适应行动实践具有一定的代表性和示范作用。根据气候变化适应行动实施框架,研究结果表明：宁夏未来气候干旱风险将增加,水资源短缺矛盾加剧,极端气候事件频率和强度加大。未来宁夏北部灌区农业应以发展节水灌溉和高效种植为主,中部以设施农业和牧业为主,南部以发展特色农业为主。气象部门和水利部门对适应技术的适应效果持乐观态度,农牧业部门和林业部门则态度谨慎。适应措施能否实施的首要条件是措施符合国家和地方的政策方针,其次是成本效益;在实施条件中,要求相对比较弱化的是公众对气候风险的认知程度以及措施的灵活调整性。在适应措施选择上,气象服务和种植结构调整成为首选的适应技术,而覆盖技术、节水技术由于更倾向于传统的技术范畴,虽然效果较好,但对其适应优先性选择存在影响。     

Wind erosion of blanket peat during a short period of surface desiccation (North Pennines,Northern England)

Strong winds are a characteristic feature of UK upland areas. Despite this, understanding of aeolian processes in upland environments of the UK is limited. This paper presents direct measurements and observations of blanket peat erosion by wind action during a two week period of desiccation in the North Pennines, Northern England. A circular configuration of mass flux sediment samplers was used to collect peat eroded by wind action from 16 cardinal compass directions. Meteorological conditions (wind speed, wind direction, precipitation and temperature) were recorded by an automatic weather station set up adjacent to the site. Surface desiccation led to peat crust erosion and dust deflation. During short (≤1 hour) periods of precipitation, wind‐driven rainfall also caused erosion. Typically, dust flux rates were up to two orders of magnitude lower than recorded during periods of sustained wet weather. Measurements demonstrate the hitherto unreported rapid switch in process regime between wind‐driven rainfall and dry blow deflation in blanket peat environments. Dry blow processes of blanket peat erosion may become more important in UK upland areas if climate change promotes more frequent surface desiccation. Copyright © 2006 John Wiley & Sons, Ltd.     

岩石变形所反映的地震作用过程--第13届国际变形机理、流变学和构造学学术会议概述

简要介绍了第13届国际变形机理、流变学和构造学学术会议的概况和特点，综述了地震变形作用的研究现状。     

基于地震作用和场地影响确定广东省设计地震动参数

在对《建筑抗震设计规范(GB50011-2001)》和《建筑工程抗震性态设计通则(试用,CECS 160:2004)》研究的基础上,根据广东地区的场地和地震作用特点,确定出了广东省甲、乙、丙类建筑不同设防水准的地震动峰值加速度,以及广东省91个城镇的特征周期分区值,为广东省建筑物抗震设计提供了更加可靠的地震动参数。     

地震作用下混合桥结合段的极限承载力分析

采用Nishiumi算法分析地震作用下混合桥结合段的极限承载力时,未考虑贯穿钢筋对混合桥结合段剪力键承载力的影响作用,分析出的极限承载力结果与实际结果差异较大。提出新的地震作用下混合桥结合段的极限承载力分析方法。通过分析计算得到栓钉类剪力键和钢筋混凝土柱类剪力键的极限承载力,设计新的极限承载力分析试验,通过设计剪力键试件、试件地震加载和试验测试点安置和测试内容安排,分析地震作用下混合桥结合段剪力键的极限承载力。分析结果说明,所提方法可准确分析地震作用下混合桥结合段剪力键的极限承载力,且分析得到的极限承载力结果与实测结果几乎一致,误差不超过7%。