The rupture history of the M_w 8.0 Jalisco, Mexico, earthquake of 1995 October 9     

Vyacheslav M. Zobin 《Geophysical Journal International》1997,130(1):220-228

  相似文献   

ON ICE FORMING NUCLEI          下载免费PDF全文

J.Rosinski  P.L.Haagenson  C.T.Nngamoto  G.Morgan 《Acta Meteorologica Sinica》1991,(4)

Cloud condensation nuclei(CCN)constitute a reservoir of latent ice-forming nuclei(IFN)active by condensation-followed-by-freezing and by sorption.Two classes of aerosol particles active as IFN by sorption werefound.The first produces IFN concentrations which are dependent on temperature only.The IFN concen-tration consecutively increases with lowering of temperature and does not respond to the increasing partialwater vapor pressure.The second produces IFN concentrations which are dependent on partial water vaporpressure only,The IFN concentration consecutively decreases with decreasing of the partial water vapor pres-sure that takes place with the lowering temperature.Sulfates(mostly ammonium sulfate)constitute an integral part of IFN active by condensation-followed-by-freezing and by sorption.Backward isentropic air parcel trajectories linked polluted air rich in sulfates andclean air with high and low concentrations of IFN active by condensation-followed-by-freezing at-19.7℃ andS_w=0.1%.The experiments were performed in a dynamic filter processing chamber with aerosol particles collectedon membrane filters.  相似文献   

滇西地区九种岩石的P波Q值     

段永康  许昭永 《地震研究》1991,14(2):171-180

本文叙述了以波传播和谱振幅比法测得的滇西地区九种岩石在不同应力状态下(σ_1=σ_2=σ_3=σ)的衰减系数,P波速度及Q值。在σ≤90 MPa时,随压力增加,衰减系数减小,P波速度及Q值增大;在σ≥120 MPa以后,衰减系数、P波速度及Q值变化甚小。其中团山砂岩及砖窑村片麻岩Q值较低。  相似文献   

花岗岩锆石中的微量元素的配分特征   总被引：8，自引：0，他引：8       下载免费PDF全文

汪相 Pupin  JP 《地质科学》1992,(2):131-140

花岗岩锆石中的微量元素(铪、铀、钇、钍、磷)的电子探针分析表明,这些元素在花岗岩锆石中皆以类质同象形式赋存,其中最小离子半径的铪以无序固溶体形式与锆完全相溶,而钇和磷在较低温度的条件下常常呈磷钇矿与锆不完全相溶;它们在花岗岩锆石中的地球化学行为是随着结晶环境的物理化学条件的变化而分异的,因此,对它们的分析研究可以揭示花岗岩的成因特征。  相似文献   

Use of the Hilbert transform to interpret self-potential anomalies due to two-dimensional inclined sheets     

N. Sundararajan  I. Arun Kumar  N. L. Mohan  S. V. Seshagiri Rao 《Pure and Applied Geophysics》1990,133(1):117-126

Self-potential anomalies due to two-dimensional inclined sheet of finite depth extent are analysed from their horizontal and vertical derivatives via the Hilbert transform. The depths to the top and bottom of the sheet and the inclination are obtained by means of simple mathematical expressions. The method is applied to a theoretical example and to a field S.P. anomaly over a sulphide deposit in the Kalava fault zone of Cuddapah basin, India. The presence of random noise is analysed for various levels and its effect is discussed. This interpretation process can be automated for all practical purposes by simple programming.  相似文献   

Ultimate bearing capacity and settlement of coal pillar sub-strata     

Yoginder P. Chugh  O. Pula  W. M. Pytel 《Geotechnical and Geological Engineering》1990,8(2):111-130

Summary This paper develops a rational approach for design of coal pillars under weak floor strata conditions considering ultimate bearing capacity (UBC) as well as pillar settlement. An approximate solution is presented for estimation of UBC for a shallow foundation on a two-layered rock system with consideration of both cohesion (c) and (ø) for both layers. Similarly, deformability underneath a full-size pillar is estimated from deformability calculated from plate loading tests. The effect of adjacent pillars on UBC and deformability of coal pillars in a panel is considered using foundation engineering analysis techniques. The design of pillars based on limiting settlements considers both differential settlements as well as mean settlement of pillar in a panel. An attempt is made to validate the proposed design approach based on field data and observations at an Illinois mine.  相似文献   

Undrained capacity of surface foundations with zero-tension interface under planar V-H-M loading     

《Computers and Geotechnics》2016

Undrained capacity of strip and circular surface foundations with a zero-tension interface on a deposit with varying degrees of strength heterogeneity is investigated by finite element analyses. The method for simulating the zero-tension interface numerically is validated. Failure envelopes for strip and circular surface foundations under undrained planar V-H-M loading are presented and compared with predictions from traditional bearing capacity theory. Similar capacity is predicted with both methods in V-H and V-M loading space while the traditional bearing capacity approach under-estimates the V-H-M capacity derived from the numerical analyses due to superposition of solutions for load inclination and eccentricity not adequately capturing the true soil response. An approximating expression is proposed to describe the shape of normalised V-H-M failure envelopes for strip and circular foundations with a zero-tension interface. The unifying expression enables implementation in an automated calculation tool resulting in essentially instantaneous generation of combined loading failure envelopes and optimisation of a foundation design as a function of foundation size or material factor. In contrast, the traditional bearing capacity theory approach or direct numerical analyses for a given scenario requires ad-hoc analyses covering a range of input variables in order to obtain the ‘best’ design.  相似文献   

水分子结构模式及液态固态水若干特征成因探讨     

濮培民  濮江平  朱政宾 《气象科学》2016,36(5):567-580

水是包括海洋大气在内的地球生态系统中极重要又有很多特殊性的物质。其特性的成因尚远非清晰。本文提出一种水分子(H_2O)结构及其固态液态水体的结构模式,探讨和模拟计算了其若干特征的成因,结果能较好符合实测值。(1)从氢(H)氧(O)原子结构和电子绕各原子核及相互绕行规律的等概率随机轨道中实现符合库伦力和开普勒运动规律的优势轨道耦合成平均状态稳定的准刚性的水分子结构。其核心是O原子与等距离分立其两侧的2个H原子构成的等腰三角形,其间距平方之比(H-H)_2/(H-O)_2=2.5;电子云活动空间为1个由4个等边三角形为面构成具有6个等长稜的正四面锥体结构水分子模式(可简称"水分子正锥体模式");该模式具有很大电偶极矩。(2)水分子的端点间在约0.27 nm距离内可以按"+""-"电荷吸引原则耦合。6个水分子将按正、负电荷对接耦合,连接成六边环形"壁"的"笼式隧道空间",可容纳其他物质,无电荷显示,电导率极地。(3)在空气中0℃以下凝结冰晶时三维不对称,"薄片"的雪花形成概率更大,其形态也按自相似原则体现了水分子结构的六角六边六针形的特征。(4)液态水分子维持固态水冰的"冰/水笼"结构模式,但由于2个氢原子上的电子同时到达1个"-"电荷端的概率为1/11,当0℃以上部份水分子能摆脱框架水分子束缚后,可以再耦合一个从框架上"脱落"的"自由水分子"使其进入水笼,从而水容积缩小;固体冰和液态水的密度之比为11/12=0.916 667。自由水分子和水笼框架上的水分子可以随时互换(在10-5s时间尺度上),并适应固体壁的形态,既是不可压缩,又有柔软、可变形特点;水在0~100℃时的空/占比达2.28,模式可解译高温高压的水汽中检测到2.16 g·cm-3,水热传导系数很大,比热容量很大,有"异常"的U形特点,且液态水的比热容量略大于固态水冰的热容量的1/2等特征。(5)讨论了水对O_2、H_2S、NaCl、KCl等的溶解度随温度变化的若干特征的成因和计算模式。通过NaCl饱和溶液实验,证实了本文模式。(6)与液态水体表面特征有关的特点及本文实际应用将在随后续文中讨论。  相似文献   

区域海洋减灾能力评估指标体系构建与权重量化   总被引：1，自引：1，他引：0  

栗健  方伟华  国志兴  贾慧聪  杨洋  赵明利  管琴乐  黎舸  李仪  蔡大浩 《海洋科学》2016,40(9):117-127

为有效开展防灾减灾,需要充分了解区域海洋减灾能力现状,从而科学确定未来减灾能力建设的优先领域及重点工程。首先梳理了能力评估与灾害管理阶段、能力建设优先领域、能力评估对象与建设主体等要素之间的关系,以及评估指标体系共性设计与区域个性的关系;其次,通过组织部门及地方的相关减灾机构与专家开展多方参与式讨论,综合了海洋、水文、气象、民政、应急、教育及综合减灾等多个领域专家的减灾经验,构建了区域海洋减灾能力评估三级指标体系,包括6个一级指标、21个二级指标及136个三级指标;然后,基于专家问卷(有效问卷69份)及层次分析(AHP)方法,量化了三级指标体系中各指标的权重。区域海洋减灾能力评估三级指标体系及指标权重成果已在相关市县开展了评估试点应用,为未来在全国范围开展区域海洋减灾能力评估奠定了良好基础。  相似文献   

A model to assess fundamental and realized carrying capacities of island ecosystem: A case study in the southern Miaodao Archipelago of China   总被引：2，自引：0，他引：2  

SHI Honghu  SHEN Chengcheng  ZHENG Wei  LI Fen  WANG Xiaoli  CHI Yuan  GUO Zhen  QIAO Mingyang  GAO Liyuan  DING Dewen 《海洋学报(英文版)》2016,35(2):56-67

Research on carrying capacity, aiming at maintaining the limited ability of the Earth's life supporting system to sustain human development, requires a comprehensive and ecosystem-based approach to monitor and assess the localized sustainability of coupled social and ecological systems. A definition termed the ecosystem-based carrying capacity of island (EBCCI) was developed in this paper of which the indices of fundamental and realized carrying capacities of island (FCCI and RCCI) were highlighted to emphasize the inter-dependencies between social systems and ecological systems. In order to avoid the difficulties and uncertainties of direct assessment, the related assessment model was established on the basis of synthetic evaluation of inherent and external factors affecting the EBCCI. The southern Miaodao Archipelago (SMA) located in the intersection of the Bohai Sea and the Yellow Sea, China, was taken as a typical example to acquire integrated recognition of the island ecosystem and its carrying capacity so as to discuss its sustainable development. The index scores of FCCI and RCCI in the SMA were 0.818 5 and 0.712 9 out of 1.0, respectively, with acceptable uncertainties. The results showed a relatively well capacity to sustain progress and relatively well realization of the carrying capacity of island ecosystem, owing to a well capacity of ecologically regulating, general performance of both ecologically supporting and resource provisioning, and a relatively high level of social supporting system. The study implied that it was critical to optimize the inter-dependencies and to sustain the relative balance between social systems and ecological systems so as to improve the RCCI and further facilitate the sustainability of SMA. The approach proposed in this paper provides a powerful tool which is well applicative to the regional level of an oceanic island or archipelago to study the sustainable development and can be further popularized to the coastal zone.  相似文献