发挥活断层研究在地震减灾中的作用   总被引：1，自引：0，他引：1  

钱洪 《四川地震》1992,(2):35-40

活断层不仅是潜在地震的震源,而且是滑坡、崩塌、泥石流之类常见地质灾害的重要发源地。本文讨论了与活断层作用有关的主要地质灾害以及活断层研究在减灾中的作用,显然在活断层分布的地区,经济有效的防灾、减灾措施应以活断层研究为先导。只有在研究未来特定时段内可能再度滑动的活段层位置,运动方式,位错量以及与之伴生的地面变形量的情况下,才可能客观地决定以减灾为目的的工程决策。  相似文献   

Removal of lead minerals from copper industrial flotation concentrates by xanthate flotation in the presence of dextrin     

Jan Drzymala  Janusz Kapusniak  Piotr Tomasik 《International Journal of Mineral Processing》2003,70(1-4):147-155

Potato starch and dextrins resulting from thermolysis of potato starch in the absence of reagents and presence of -amino acids are promising depressants for separation of lead and copper minerals present in the Polish industrial copper concentrates. The polysaccharides were used for differential xanthate flotation of the final industrial concentrates produced by flotation with sulfhydryl collectors in the absence of depressants. The polysaccharides depressed galena and provided froth concentrate rich in chalcocite and other copper minerals as well as cell product containing lead minerals. The best results of separation were obtained in the presence of plain dextrin prepared by a thermal degradation of potato starch. The industrial concentrate containing 18.5% Cu and 5.5% Pb was divided into a froth product containing 38.1% Cu with 77% recovery of copper and a cell product assaying 7.3% Pb with 83% recovery of lead. It was accomplished using 2500 g/t of dextrin, 50g/t of potassium ethyl xanthate, and 50 g/t of frother (α-terpineol). The pH of flotation was 8.0–8.2.  相似文献   

Study on evaluation of cities’ ability reducing earthquake disasters     

Zhang Feng-hua  Xie Li-li  Fan Li-chu 《地震学报(英文版)》2004,17(3):349-361

Cities’ ability reducing earthquake disasters is a complex system involving numerous factors, moreover the research on evaluating cities’ ability reducing earthquake disasters relates to multi-subject, such as earthquake science, social science, economical science and so on. In this paper, firstly, the conception of cities’ ability reducing earthquake disasters is presented, and the ability could be evaluated with three basic elements — the possible seismic casualty and economic loss during the future earthquakes that are likely to occur in the city and its surroundings and time required for recovery after earthquake; based upon these three basic elements, a framework, which consists of six main components, for evaluating city’s ability reducing earthquake disasters is proposed; then the statistical relations between the index system and the ratio of seismic casualty, the ratio of economic loss and recovery time are gained utilizing the cities’ prediction results of earthquake disasters which were made during the ninth five-year plan; at last, the method defining the comprehensive index of cities’ ability reducing earthquake disasters is presented. Thus the relatively comprehensive theory frame is set up. The frame can evaluate cities’ ability reducing earthquake disasters absolutely and quantitatively and consequently instruct the decision-making on reducing cities’ earthquake disasters loss. Foundation item: State Important Research Project of China (95130603).  相似文献   

Study on evaluation of cities ability reduc-ing earthquake disasters     

张风华  谢礼立  范立础 《地震学报(英文版)》2004,17(3)

Introduction At the end of last century, the Committee of International Decade for Natural Disaster Re-duction had called on evaluating the ability reducing earthquake disasters of cities. However, since efficient method to assess earthquake loss of cities does not exist, the proposition did not come true. In 1994, China government put forward that the cities with dense population or developed economy and the areas off the seashore should have the ability to resist earthquake (M=6). Un-dou…  相似文献   

安徽铜陵矿集区海西期喷流沉积流体系统时空结构   总被引：20，自引：3，他引：20  

杨竹森  侯增谦  蒙义峰  曾普胜  李红阳  徐文艺  田世洪  王训诚  姚孝德  姜章平 《矿床地质》2004,23(3):281-297

铜陵矿集区是长江中下游成矿带七大矿集区之一，构造上经历了晚古生代的陆缘裂陷、中三叠世的陆-陆碰撞和侏罗纪—白垩纪的陆内构造-岩浆活动。晚石炭世的海底喷流沉积形成了广泛分布的块状硫化物，除部分构成块状硫化物矿床外，还为燕山期中酸性岩浆活动形成的矽卡岩型矿床提供了部分硫和金属物质。为了查明海西期喷流沉积流体系统及其时空展布特征，在铜陵矿集区内开展了以流体活动记录为对象的蚀变-流体填图工作。结果显示，海西期喷流沉积流体系统不仅形成以块状硫化物为主体的喷流沉积记录，而且在下伏岩系中遗留了区域规模的流体蚀变记录。以块状硫化物为主体的喷流沉积记录构成3个喷流沉积旋回，在垂向上和横向上均具有成分和结构的分带性。流体蚀变记录在上部构成顺层蚀变带，在中部构成沿断裂和裂隙充填的石英一硫化物脉体群。在下部则构成半整合蚀变带，表明喷流沉积流体系统由下渗的海水在下部半整合蚀变带形成储集区，经高地热异常的加热后，沿中部脉体群向上迁移，在进入顺层蚀变带后沿砂岩层向两侧扩散，最后经同生断裂和裂隙向海底喷出。块状硫化物与蚀变岩、喷流沉积旋回及硫化物硫同位素的空间展布特征，显示区内存在3个受基底断裂控制的NWW向延伸的流体活动域，包含6个以上的流体储集区域，每个流体储集区域之上发育多个流体上升中心和海底喷流中心。  相似文献   

沙柳沙障的防风固沙效益研究   总被引：48，自引：14，他引：48  

高永  邱国玉  丁国栋  清水英幸  虞毅  胡春元  刘艳萍  户部和夫  王义  汪季 《中国沙漠》2004,24(3):365-370

研究测定了1m×1m,1m×2m,2m×2m,2m×3m,2m×4m,2m×5m,3m×3m,3m×4m,4m×4m,4m×5m,3m×6m等11种规格沙柳沙障内的风沙活动过程和分布规律。结果说明,不同规格沙障内输沙率随着风速的变化其变化趋势不同,小规格沙障内输沙率与风速呈对数曲线关系,大规格沙障内输沙率与风速之间呈指数曲线关系。沙柳沙障中近地表0～4cm范围内,风沙流中的相对含沙量沙丘下部明显大于沙丘中部和上部,说明沙障导致了近地表风沙流结构发生变化。面积等于或小于1m2的沙障可以完全控制地表风蚀,当沙障面积增加到一定程度后,风蚀深度增加很快。不同规格沙障的防护效益,在大风条件下,小规格沙障的成本效益高于大规格的沙障;在小风情况下,大规格沙障的成本效益大于小规格沙障。  相似文献   

我国地质灾害研究若干问题探讨   总被引：2，自引：0，他引：2  

陈奇 《地球科学进展》1993,8(1):35-38

简要概括了我国地质灾害研究的现状,对地质灾害的宏观规律性、基础理论研究与防治对策、治理实践等方面进行了总结,并论述了在地质灾害研究中应注意的系统性、实践性和社会性问题。  相似文献   

Pb—Sn—Fe—Sb—S体系相关系     

吴大清 《矿物学报》1989,9(3):232-240

用抽空石英管法研究以Fe_(0·96) Sb_(2·04) S_(4·12)为投影顶点,8×(PbS-SnS-SnS_2)为投影平面的Pb-Sn-Fe-Sb-S体系的相图表明,由于Pb(?)Sn~(2+)之间互相取代,500℃时辉锑锡铅矿固溶体中Sn~(2+)变化范围(以单位分子式11个金属原子总数为计量)是0—4.8个原子,400℃时则为0—4.0个原子。同时,Sn~(4+)变化范围是1.3—2.3个原子和1.5—2.1个原子。圆柱锡矿固溶体变化范围较小。500℃时Sn~(2+)变化范围是0.4—1.8个原子,400℃时为0.5—1.7。Sn~(+4)变化范围则分别为3.2—4.2个原子和3.3—4.2个原子。变更Fe含量(0.81—1.09)及Sb含量(1.83—2.29)进行的几组合成实验表明,上述两个矿物中Fe、Sb含量变化范围很小,不超过±0.15个原子。辉锑锡铅矿固溶体可与方铅矿、块硫锑铅矿、针硫锑铅矿、硫锡铅矿、硫锡矿、圆柱锡矿等形成平衡结线。而圆柱锡矿不与方铅矿、硫锡矿、硫锡铅矿形成平衡结线,但可与辉锑矿、SnS_2及上述其他矿物形成平衡结线。结合锡的硫化物及氧化物(锡石)热力学稳定场计算表明,在本体系内辉锑锡铅矿在300℃时稳定区的硫活度在lga_(s2)=-20(atm)附近,氧活度小于lga_(o2)=-40(atm),而圆柱锡矿稳定区硫活度大于lga_(s2)=-10(atm)。  相似文献   

我国首例离层注浆减沉试验的再思考     

杨伦 《中国地质灾害与防治学报》2006,17(1):102-104,123

20a前在抚顺老虎台煤矿512采区进行的我国首例离层注浆减沉试验为探索煤矿可持续开采技术提供了宝贵经验。试验采区地表下沉比预计小的真正原因是采空区密实水砂充填(充满率为70%~85%),覆岩中巨厚绿色页岩层遇水碎胀(碎胀率为185%)和大采深极不充分采动(采动程度系数为0.14)。离层注浆主要起到了使绿色页岩层碎胀的作用,而留在覆岩离层中的粉煤灰量极少(只占煤炭采出体积的3%)难以起到减沉作用。试验结果说明该技术在缓沉方面比减沉更有效。  相似文献   

秦岭-黄淮平原交界带河流减水效应及其驱动因子分析     

管华  李艳 《地域研究与开发》2007,26(1):95-98

中国东部河流的径流量一般具有自上游向下游沿程逐渐增大的趋势,而在秦岭-黄淮平原交界带,河流径流量具有沿程减小的特征,即山地-平原交界带"河流减水效应".基于5条主要河流上27个水文站1956～2000年共45年观测资料的分析表明,秦岭-黄淮平原交界带及其邻近区域的河流基本上都存在较为明显的减水河段,出现部位多为交界带的中部和下部及其下游邻近地区,其驱动因子主要是地表组成物质的垂向二元结构.  相似文献