西藏蛇绿岩中二种合金矿物新变种

在西藏雅鲁藏布江蛇绿岩带的东部，距拉萨200km的泽当罗莎蛇绿岩的铬铁矿中，发现有种类繁多的合金矿物，铬铁镍矿和依铁镍矿就是其中二种。铬铁镍矿分子式：Ni0.41Fe0.35Cr0.24，为等轴晶系，空间群为Fm3m，晶胞参数a=0.35622(2)nm。铱铁镍矿分子式：Ni0.66Fe0.18Ir0.16，属等轴晶系，空间群Oh^5-Fm3m，晶胞参数a=0.46486(4)mm。     

边坡锚固工程中广义Burgers模型的应用研究

流变是岩土材料的基本力学特性,流变效应是影响边坡变形及稳定性的重要因素。边坡锚固工程中,坡体介质应力调整和锚固力松弛直接影响加固坡体工程的稳定性,对工程安全性起着制约作用。考虑到坡体蠕变影响与锚固应力松弛的相互作用,结合工程实践,采用弹簧和Burgers并联模型进行锚索加固坡体的耦合蠕变分析,探讨其理论模型,获得了蠕变耦合模型的黏弹性流变参数。流变模型与试验结果的比较,显示了所建模型的正确性与合理性。     

广元三堆镇康家沟剖面寒武系地层及沉积特征

丹凤群分布于天水市南部,向东延入陕西凤县。通过原岩恢复,其下部层位的岩石以变玄武岩为主,夹安山岩、石英岩、大理岩,中部为变石英砂岩夹玄武岩、薄—微层状石英岩夹安山岩、英安岩,上部为玄武岩、玄武安山岩、安山岩、石英砂岩、大理岩夹流纹岩及硅质条带。火山岩为碱性—拉斑系列,锶同位素初始比值低,地球化学特征与岛弧玄武岩的地球化学模型相似。通过对丹凤群火山岩地质特征、岩石组合、岩石地球化学特征的综合分析,认为丹凤群的沉积环境,处于当时的秦岭古陆南侧的古大洋岛弧。     

Seismic reflection evidence of crustal duplexing and lithospheric underthrusting beneath the western Qilian Mountains,northeastern margin of the Tibetan Plateau

The geological processes responsible for outward growth of the Tibetan Plateau are debated.The Qilian Mountains on the northeastern margin of the plateau comprise one of the youngest structural components of the plateau whose understanding is key to deciphering the broader geological evolution of the region.Here,based on a reprocessed deep seismic profile which was originally collected during the 1990 s across the northeast margin of the western Qilian Mountains and previous geological and geophysical data,we find evidence for decoupled crustal deformation that was partitioned by a decollement,in which lowercrustal deformation featured by local duplexing preceded upper-crustal deformation featured by imbricate thrusts.Furthermore,we propose that the Asian lithospheric mantle is being underthrust beneath the western Qilian Mountains,as inferred from patterns of lower crustal deformation which is marked by the Moho geometry.Integrating these results yields a better understanding of lithospheric deformation of western Qilian Mountains,northeastern margin of the plateau during the Cenozoic.     

江西省地震工程地质现状与防灾展望——兼谈汶川地震对江西的启示

(1 概况.江西省位于欧亚板块东南部,跨扬子准地台和华南褶皱系两个地块(24°29′～30°04′N,113°34′～118°29′E).其南部地处华南沿海地震带,主要受河源一邵武断裂带与南岭纬向构造带控制;北部地处长江中游地震带,主要受郯城一庐江断裂带和扬州一铜陵断裂带控制,地质构造复杂,新构造及现代构造运动活跃,历史上曾多次发生破坏性地震.     

Stretching characteristics and its dynamic significance of the northern continental margin of South China Sea

To investigate the thinning of the whole crust, and the contribution of the upper versus lower crust to the stretching since Cenozoic, we calculated the stretching factor of the northern margin of South China Sea with data such as whole crustal thickness, depth of Cenozoic sedimentary basement and the horizontal displacement of faults. An isometric line drawing on whole crustal stretching factor is then obtained. Along the seismic Line 1530 in Baiyun sag, we also calculated the stretching factors of the upper and lower crust. The results suggest that the whole crustal thickness decreases seaward while the whole crustal stretching factor increases from shelf to slope. The Moho upwells highest beneath where the crust is thinned most. The value of the whole crustal stretching factor ranges from 1.5 to 6. Two areas were thinned intensely: the center of Yinggehai Basin, and the Baiyun sag in the Pearl River Mouth Basin. The calculation of the upper and lower crustal stretching factors from DSP1530 in Baiyun sag shows that the original crust of Baiyun sag should be thinned before deformation. Its pre-Cenozoic evolution as well as tectonic position during Cenozoic might be responsible for that.     

面向地震巨灾保险的建筑特性快速提取方法

房屋建筑分类是抗震设计和地震风险分析的基础,是巨灾保险的纽带环节,也是结构易损性准确、完备分析的前驱保障,快速获取建筑特性参数非常关键。基于影像数据获取结构特性相比传统手段具有显著优势,然而其准确性具有一定挑战性,从影像数据得到实时的、较准确的结构特性成为地震保险数据获取技术的关注焦点。本文采用深度学习方法开展从影像数据中提取面向地震保险需求的建筑特性数据,构建基于深度学习方法的建筑高度识别模型和基于机器视觉的建筑高度识别方法,运用基于Xception神经网络深度学习和机器视觉的模型,对北京地区的建筑高度进行模型测试,该方法可为地震保险分析提供重要的基础数据支持。     

Preliminary results of measuring the crustal deformation in Qinghai-Xizang area using GPS technique

GPS repetition measurement tbta in Qinghai-Xizatlg (Tibetan) area in 1992 and 1994 have been used to determine the change rates of seven bascline vectors of Lhasa-Wenquan, etc. It is the first time to obtain the direct observation results of the large-scale crustal horizontal motions in this area. Thesc preliminary results also for the first time provide the direct observation evidence for some important geophysical and geological viewpoints, such as the northward gradual reduce of the effect of the northward push-pressing to Eurasian continent by Indian Plate in the Qinghai-Xizang area, having a southward strike slip movement of the Chuan-Dian diamond block, etc.     

A study on relation between acoustic emission and characteristic displacement field on the sample with multi en echelon structures — The theoretic and experimental explorations of strain gap

Based on the phenomena that the deformation gap was observed before the great Tangshang earthquake, this paper discusses the strain gap according to test and theory. The (strain) patterns were recorded photographically by realtime holographic interferometry and shadow optical method of caustics, as soon as the loading process started. In the meantime, the AE (acoustic emission) signals were recorded by a micro crack information storage-analysis system. According to damage theory and location of micro fracture, we have studied the stain gap and gained: a) It is necessary that strain gap appears under the condition of linear elasticity theory, and its situation is relatively stable, corresponding to stress concentration. b) Micro fractures, which appear initially at area of high stress, occur rarely at the strain gap, and their locations are finally in the zone between the stress concentration area and the strain gap, which indicate the clusters or groups. However, the major macro fracture (final rupture) started from the shadow areas, and then grew quickly towards the strain gaps, which resulted in failure of sample. Foundation item: The Dual Project of China Seismological Bureau (9691309020301), the Specialized Funds for National Key Basic Study (G1998040704), the project for the MOST under contract (2001BA601B02) and Youth Funds for applied basic study of the Science and Technology Bureau of Yunnan Province (98D019Q).     

Introduction of structural aseismic research in China in recent four years

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…