基于可靠度理论的黄土高边坡优化设计   总被引：11，自引：2，他引：9  

叶万军  折学森  陈志新  宋建华  邵铁全 《地球科学与环境学报》2005,27(2):82-85

对黄土高边坡进行可靠性分析，应用数学原理和优化原理，建立了黄土高边坡的优化模型，对铜黄一级公路黄土高边坡进行分析验证。结果表明，该方法计算的结果与实际较接近．应用中易操作。  相似文献   

利用地震矩张量反演鲜水河断裂带现今运动学特征     

孙建中  施顺英  周硕愚  张爱华 《大地测量与地球动力学》1994,(4)

本文探讨了利用地震矩反演断裂形变带运动学参数的基本理论和方法，将其初步应用于鲜水河断裂形变带变形分析和运动机制的研究。结果表明，鲜水河断裂带呈现出走向拉伸、倾向压缩的形变格局，由地震矩反演的断裂带剪切形变速率（１０．９ｍｍ／ａ）与用地质学估算方法（１７ｍｍ／ａ）和现今地壳形变测量（８ｍｍ／ａ）的结果相当。同时，反演出的应变主方向能解释鲜水河断裂现今活动分段性特征以及多种滑动方式共存的现状，从而证明该方法是目前研究区域运动学问题切实有效的手段之一。  相似文献   

沉积盆地有机质自由基热演化特征及其作为古温标的探索   总被引：1，自引：0，他引：1  

徐二社  邱楠生  秦建中  郑伦举 《地质学报》2008,82(3):413-419

恢复沉积盆地热历史的方法主要有古地温指标法和动力学模拟法两类.古温标法中最常用的为有机质成熟度和矿物裂变径迹,动力学模拟法中最常用的是盆地的拉张模型和挤压模型.本文针对Ⅰ型有机质自由基浓度作为沉积盆地古温标进行了探索研究.分析了自然演化系列Ⅰ型有机质的自由基的热演化特征;根据自然演化系列的Ⅰ型有机质自由基浓度及时间-温度指数(TTI)数据,对热模拟实验下的Ⅰ型有机质自由基浓度及时间-温度指数(TTI)值进行校正,由校正后的数据初步建立了Ⅰ型有机质的自由基浓度(Ng)与时间-温度指数(TTI)的定量模型.  相似文献   

Isotopes and Geochronology of the Meixian-type Pb-Zn-(Ag)Deposits,Central Fujian Rift,South China:Implications for Geological Events     

FENG Chengyou  ZHANG Dequan  LI Daxin  SHE Hongquan  DONG Yingjun 《《地质学报》英文版》2008,82(4):826-837

Central Fujian Rift is another new and important volcanogenic massive sulfide Pb-Zn polymetallic metallogenetic belt. In order to find out the material genesis and mineralization period of Meixian-type Pb-Zn-Ag deposits, S and Pb isotope analysis and isotope geochronology of ores and wall rocks for five major deposits are discussed. It is concluded that the composition of sulfur isotope from sulfide ore vary slightly in different deposits and the mean value is close to zero with the 834S ranging from -3.5‰ to ＋5.6‰ averaging at ＋2.0‰, which indicates that the sulfur might originate from magma or possibly erupted directly from volcano or was leached from ore-hosted volcanic rock. The lead from ores in most deposits displays radioactive genesis character （206pb/204pb〉18.140, 207Pb/204pb〉15.584, 208pb/204pb〉38.569） and lead isotope values of ores are higher than those of wall rocks, which indicates that the lead was likely leached from the ore-hosted volcanic rocks. Based on isotope data, two significant Pb-Zn metallogenesis are delineated, which are Mid- and Late-Proterozoic sedimentary exhalative metailogenesis （The single zircon U-Pb, Sm-Nd isochronal and Ar-Ar dating ages of ore- hosted wall rocks are calculated to be among 933-1788 Ma.） and Yanshanian magmatic hydrothermal superimposed and alternated metallogenesis （intrusive SHRIMP zircon U-Pb and Rb-Sr isochronal ages between 127-154 Ma）.  相似文献   

科技进步与金属矿产资源供应——兼论我国可持续发展的资源基础     

王瑞廷  佘岳峰  任小华 《矿产与地质》2008,22(6):570-574

科技进步为金属矿产资源的勘查开发、获取供应提供理论指导和技术支持,并在很大程度上决定着地矿产业的可持续发展。在21世纪绿色矿业的崛起和新的循环经济模式下矿业文明的振兴更是离不开现代科学技术,二者相辅相成,这对巩固我国可持续发展的资源基础意义重大。对于我国的资源开发供应,资源保障是前提基础,科学技术是方法手段,环境效益是发展目标,三者应协同推进,不可偏废。  相似文献   

浅析旅游地图的网络化发展     

许建中  徐剑  任小龙 《现代测绘》2008,31(2):45-46

旅游地图是人们旅行和导购导游的常用工具,对各地旅游业的发展具有十分重要的推动作用。本文论述了网络化旅游地图发行方式上所具有的优势,分析了当前旅游地图网络化的发展现状及存在问题,探讨了加快旅游地图网络化发展的策略与措施。  相似文献   

Calorimetric study of the coesite-stishovite transformation and calculation of the phase boundary     

Jun Liu  Letitia Topor  Jianzhong Zhang  Alexandra Navrotsky  Robert C. Liebermann 《Physics and Chemistry of Minerals》1996,23(1):11-16

High temperature drop-solution calorimetry in molten 2 PbO · B₂O₃ at 1044 K for coesite and stishovite polymorphs of silica was carried out to determine the enthalpy of the coesite-stishovite transition. These experiments were performed on high-purity, single-phase samples of coesite and stishovite. Our new value for the enthalpy of the coesitestishovite transition (ΔH ₂₉₈ ⁰ ) is 29.85 ± 0.78 kJ/mol, which is about 35% lower than previously reported by Akaogi and Navrotsky (1984) and Holm et al. (1967), but which compares well with new measurements by Akaogi et al. (1994b). Using these new data, we have calculated the equilibrium phase boundary between coesite and stishovite and obtained a slope, dP/dT=0.0031 (2) GPa/K. This calculated slope is in good agreement with that determined [0.0026 (2) GPa/K] from the in-situ X-ray diffraction study of Zhang et al. (1996).  相似文献   

一次诱发山地灾害突发性暴雨数值模拟及诊断分析   总被引：5，自引：0，他引：5  

慕建利  杜继稳  张弘  侯建忠  赵奎锋 《气象》2005,31(12):36-40

应用MM5V3.5中尺度非静力数值模式对2003年7月14～15日发生在陕西省一次区域性暴雨过程进行数值模拟和诊断分析,结果发现,西太平洋副热带高压西侧的暖湿气流和新疆冷空气是这次暴雨的主要影响系统,充沛的水汽输送、能量的积聚和强烈的上升运动为暴雨的发生提供了充分的条件,700hPa低涡、切变线是暴雨形成的触发机制.模拟结果表明：涡度场和散度场及垂直上升运动互耦;特强辐合辐散柱的出现早于强涡度柱,而深厚的强气旋性涡柱则几乎与暴雨最强盛时期同时出现.  相似文献   

Geochronology of Gold Deposits and Its Implication for Metallogenesis in the Fengxian-Lixian Area, Qinling Orogenic Belt, China   总被引：2，自引：0，他引：2  

Jianzhong FENG  Dongbo WANG  Xueming WANG  Shicai SHAO  Tifeng LI 《Resource Geology》2002,52(3):263-272

Abstract: A series of super large‐scale and large‐scale Pb and Zn, and Au deposits are distributed in the Qinling orogenic belt, China. Gold deposits were generally ascribed to Carlin‐type originated from circular meteoric water. Visible and coarse‐grained gold (up to over 3mm in grain size) was recently identified in some gold deposits in the Fengxian‐Lixian area, Qinling. Au‐bearing quartz lodes related to magmatism were discovered in the Xiaogouli gold deposit. Two types of Au‐bearing quartz veins, i.e., NW‐trending quartz veins and NE‐trending quartz veins cutting strata are widely present in the Baguamiao gold deposit. Both are spatially associated with each other. The former is generally snake–like, S‐shape or zigzag, which was resulted from plastic deformation by ductile shearing, being generally cut by the latter. The latter is generally linear with widely developed bleaching alteration zones in its adjacent wall rocks, which symbolizes the superimposition of brittle deformation and filling and metasomatism of magmatic hydrothermal solution in ductile shear zones after uplifting of the shear zones near the surface. The NW‐trending quartz veins contain Au of lower than 3ppm. The NE‐trending quartz veins contain Au of more than 3 ppm, so that NE‐trending quartz veins and the adjoining altered rocks are important ores. The NW‐trending Au–bearing quartz vein was dated as 210.61.26 to 232.581.59 Ma by ⁴⁰Ar–³⁹Ar method, i.e., late Indosinian epoch (Triassic). The NE‐trending Au–bearing quartz vein was dated as 131.910.89 to 197.451.13 Ma by ⁴⁰Ar–³⁹Ar method, i.e., Yanshanian epoch (Jurassic). The ⁴⁰Ar–³⁹Ar age of the NW‐trending Au–bearing quartz veins represents the age of the ductile shear formation. The isotope data of the NE‐trending quartz veins indicate that gold mineralization was closely related to Indosinian and Yanshanian granite intrusives not only in time and space, but also in origin.  相似文献   

高原交通干线对土地利用和景观格局的影响——以兰州至格尔木段为例   总被引：12，自引：1，他引：12  

阎建忠  张镱锂  刘林山  沈振西  刘燕华  郑度 《地理学报》2003,58(1):34-44

运用景观生态学方法和Arc/Info软件，研究1995年至2000年兰州至格尔木铁路沿线的区域土地利用和景观格局变化，分析交通干线（公路和铁路）的影响程度与范围。主要结果如下：（1）东线土地利用和景观格局没有发生显著变化，西线土地利用和景观格局变化较大；（2）东线缓冲带土地利用程度综合指数没有显著变化，西线缓冲带土地利用程度综合指数明显升高。缓冲带综合土地利用动态度的变化反映了交通干线的轴向影响规律；兰州至西宁铁路对土地利用变化的显著影响范围是5km，青藏铁路对土地利用变化的显著影响范围是7km；（3）9个城市缓冲带的土地利用变化分析表明：城市扩展主要发生在1km缓冲带内。  相似文献