我国西部内陆型晚冰期环境特征的湖相沉积记录

根据新疆东部巴里坤湖沉积地层及孢粉,地球化学元素和有机质含量波动特征,同时结合年代的测定,本文对由其所揭示的晚冰期中的几次冰阶与间冰阶交替出现的内陆型环境演变行征进行了研究,指出此阶段中环境演变仍具有相对冷湿与晚干交替的匹配模式。广泛的区域性对比表明,它的出现具有全球一致性,同时又具有区域性差异特征,这种非线性的气候变化对于研究气候突变事件的发生机制具有重要意义。     

柴达木盆地英雄岭构造带油气藏地质特征

为总结柴英雄岭构造带油气藏地质特征和主控因素,以该区深层和浅层油气藏为研究对象,对油气藏的构造、储层、油气源和成藏演化模式等方面进行了对比研究。结果表明:(1)英雄岭构造带构造样式自西向东变化显著,英西—英中纵向上表现为“双层结构”,而英东构造样式相对简单;(2)英西—英中碳酸盐岩储层主要储集空间为白云岩晶间孔,局部发育溶蚀孔和裂缝集中区,英东碎屑岩储层,主要发育粒间孔、少量粒间溶孔和裂缝;(3)油源对比表明,下干柴沟组上段为区内主力烃源岩;(4)天然气组分及同位素指标表明英西和英中的CH₄主要来源于原油伴生气,而英东为凝析油伴生气;(5)由于岩盐层封盖作用,英西—英中深层形成自生自储的异常高压油气藏,而英东虽缺乏盐岩盖层,由深至浅地表现为幕式充注成藏。     

Controls on the geotechnical response of sedimentary rocks to weathering

Weathering reduces the strength of rocks and so is a key control on the stability of rock slopes. Recent research suggests that the geotechnical response of rocks to weathering varies with ambient stress conditions resulting from overburden loading and/or stress concentrations driven by near-surface topography. In addition, the stress history experienced by the rock can influence the degree to which current weathering processes cause rock breakdown. To address the combined effect of these potential controls, we conducted a set of weathering experiments on two sedimentary lithologies in laboratory and field conditions. We firstly defined the baseline geotechnical behaviour of each lithology, characterising surface hardness and stress–strain behaviour in unconfined compression. Weathering significantly reduced intact rock strength, but this was not evident in measurements of surface hardness. The ambient compressive stress applied to samples throughout the experiments did not cause any observable differences in the geotechnical behaviour of the samples. We created a stress history effect in sub-sets of samples by generating a population of microcracks that could be exploited by weathering processes. We also geometrically modified groups of samples to cause near-surface stress concentrations that may allow greater weathering efficacy. However, even these pronounced sample modifications resulted in insignificant changes in geotechnical behaviour when compared to unmodified samples. The observed reduction in rock strength changed the nature of failure of the samples, which developed post-peak strength and underwent multiple stages of brittle failure. Although weakened, these samples could sustain greater stress and strain following exceedance of peak strength. On this basis, the multi-stage failure style exhibited by weaker weathered rock may permit smaller-magnitude, higher-frequency events to trigger fracture through intact rock bridges as well as influencing the characteristics of pre-failure deformation. These findings are consistent with patterns of behaviour observed in field monitoring results. © 2019 John Wiley & Sons, Ltd.     

基于三维图像模式识别的西藏东南部地震灾害损失风险评估

本文在对西藏东南部各县的建筑类型、数量、易损性调查的基础上,对不同类型的建筑建立了模式类向量,使用三维图像模式识别技术估计了各类型建筑在西藏东南部各县市的数量分布,建立了不同建筑物的结构易损性和人口易损性模型,并且估算了西藏东南部各县在遭遇一次设定地震时的损失分布和基于危险性的未来50年可能的损失分布情况.本文研究表明,若曲松—桑日发生7.5级地震,可能造成拉萨、山南两市较重的人员伤亡,其中曲松县和乃东区伤亡最重.西藏东南部未来50年建筑地震风险最高的地区是拉萨市区、林芝市区和错那县,其中拉萨市区的建筑财产损失风险最高.     

附设黏滞阻尼器的传统风格建筑混凝土梁-柱节点动力循环荷载累积损伤分析

为研究附设黏滞阻尼器的传统风格建筑混凝土梁-柱节点地震损伤演化规律,进行6个该类型构件的动力荷载试验,并分别采用位移型、能量型及位移-能量混合型损伤模型对其进行全过程评价,采用Park-Ang模型分析试件黏滞阻尼器型号、试件类型等因素对混凝土传统风格建筑梁柱节点损伤行为的影响。研究结果表明：附设黏滞阻尼器可显著提升传统风格建筑节点的承载能力、延性性能及耗能能力,结构的抗震性能得到较大幅度的提升;Park-Ang损伤模型与Banon损伤模型适用于传统风格建筑节点损伤演化规律的描述,建议对该类型节点的损伤规律表征选用该损伤模型。黏滞阻尼器型号可在一定程度上影响传统风格建筑的损伤演化发展;设计阻尼力大的试件虽然延性有所提高,但受荷过程中累积损伤也较大。     

船载物探电子设备的接地问题及解决方案

船栽物探电子设备,是一个电气结合复杂的数据采集记录系统.各系统电子线路因船舶配电方式、工作环境的特殊性,其接地很重要,但容易被忽视.而接地处理不当,在使用时会受到噪声干扰、振荡;或造成仪器的输出榆入电路损坏,不能正常工作.更严重地甚至机壳漏电,危及人身安全.船栽物探电子设备接地问题.可分为"接地保护"和"接地故障"."接地保护"是将电气设备的金属外壳、支架和电缆的护套与大地等单位的金属船体(船壳)作永久性良好的电气连接,它分为保护接地和功能接地."接地故障"是指因设备不正确接地或由于绝缘层的破损、老化及环境恶劣引起绝缘电阻低下或者接地干扰等问题.文中从船载物探电子设备的使用特性出发.讨论在实际接地处理中出现问题的原因,分析了各种接地干扰的原理.并提出了相应的解决方案,对于船栽物探电子设备的实际安装应用有一定的指导意义.