短周期仪器记录在远震分析中的应用     

许康生 《地震地磁观测与研究》1992,13(2):15-19

地震泼由多种频率成份组成,在其传播过程中。由于地球介质的滤波作用,随着传播距离的增大。高频成份逐渐被衰减。周期越大的成份传播越远。因此,在地震观测上,不同频带的地震仪用于观测不同震中距范围的地震,使仪器较好地响应,就我国台网而言,短周期仪用于地方震、近震的监测,中长周期仪和长周期仪用于远震,极远震的监测,其中长周期仪偏重于记录极远震。但作者在实际分析工作中注意到,短周期仪的记录应用于远震,极远震的分析,显示出独特的作用,充分挖掘和利用短仪资料,将会更加丰富远震、极远震的震相资料。本文以高台地震台的资料为依据,从震中距和震级角度,与中长仪和长仪作比较,对短仪记录远震、极远震的震相及特征作了统计分析与初步探讨,并对新疆地区“影区”地震S波的记录、日本地区地震_PPcP等震相的出现提出了现象的存在,给出了相应的观测结果,以待步一步研究。  相似文献   

矿物标型六性及其在胶东金矿中的应用   总被引：2，自引：0，他引：2  

陈光远  孙岱生 《吉林地质》1990,9(3):1-8

目前矿物标型研究和应用已进入一个新的阶段。作者从哲学的高度,把国内外矿物标型特征的分散研究加以集中概括和总结,提出了“矿物标型六性”的普遍规律,即普遍性、特殊性、变化性、相应性、继承性和分带性,对矿物标型特征研究具重要的指导意义。这些规律在胶东金矿中得到广泛应用,并已取得良好效果。  相似文献   

饱和软土压缩曲线的“反常”现象     

冯铭璋  王兴涛 《上海国土资源》1990,(3):30-37

饱和软土压缩试验时,经常出现压缩曲线“反常”、压缩系数“倒大”的现象。它是土的原始结构发生破坏前后的不同压缩性的客观反映。饱和软土的结构力很微弱,唯质量好的原状土才能见到这种“反常”。应从成孔、取样、测试及资料整理等多个环节保证其工程意义。  相似文献   

论四川盆地三叠系地下水水文地质条件   总被引：3，自引：0，他引：3       下载免费PDF全文

林耀庭 《盐湖研究》2006,14(1):1-8

四川盆地三叠系地下水可划分出碎屑岩孔隙裂隙和碳酸盐岩岩溶裂隙两大储集类型。按此处构造开启程度和埋深条件等的不同,下中三叠统地下水有沉积变质水和渗入淋滤水两种基本成因类型,水动力特征各异。沉积变质水处于深埋封闭条件,受地静压力驱动控制;渗入淋滤水分布于背斜露头区和浅部地区,受静水压力驱动控制。并由此控制了盆地三叠系盐类的保存条件。  相似文献   

Flotation and depression control of arsenopyrite through pH and pulp redox potential using xanthate as the collector     

A. López Valdivieso  A.A. Sánchez López  C. Ojeda Escamilla  M.C. Fuerstenau 《International Journal of Mineral Processing》2006

The role of pH and pulp redox potential (E_H) to control the flotation and depression of arsenopyrite has been investigated through studies on microflotation of arsenopyrite crystals and batch flotation of an arsenopyritic ore using isopropyl xanthate as collector. The transition between flotation and depression of arsenopyrite is established by the reversible potential of the xanthate/dixanthogen couple. Adsorption of arsenate ions on ferric hydroxide has been studied through electrokinetics to delineate mechanisms involved in the depression of arsenopyrite using oxidants. Chemical binding between arsenate species and ferric hydroxide sites on arsenopyrite is suggested as the mechanism responsible for depression of arsenopyrite. E_H conditions are given for the flotation and depression of arsenopyite at various pH values for the arsenopyritic ore.  相似文献   

Indium Enrichment in the Meng'entaolegai Ag-Pb-Zn Deposit, Inner Mongolia, China   总被引：3，自引：0，他引：3  

Qian Zhang    Xiaoqing Zhu    Yuliang He  Junjie Jiang  Dapeng Wang 《Resource Geology》2006,56(3):337-346

Abstract. The Meng'entaolegai In-rich Ag-Pb-Zn deposit is located in the eastern part of Inner Mongolia. It is one of the In-richest deposits in China. Large amounts of quartz and sulfide minerals constitute a hydrothermal quartz-sulfide vein deposit within a Hercynian acidic granite massif, which occupies an area of about 400 km². Thirty-six orebodies, controlled strictly by the E-W trend faults, are found in the orefield of 6 km in length from east to west and 200 to 1,000 m in width from south to north. The ore minerals are mainly galena, sphalerite and pyrite, and subordinate chalcopyrite, arsenopyrite, cassiterite and stannite with many Ag-minerals. The gangue minerals are mainly quartz, calcite, sericite and chlorite. Economic components of the deposit are dominated by Pb andZn (reserves of Pb and Zn are 0.17 Mt and 0.37 Mt, and their grades are 1 % and 2.3 %, respectively), with Ag, Sn, In and Cd (1,800 t Ag, >2,000 t Sn, >500 t In and 1,800 t Cd) as by-products. Indium is highly enriched in ores and its contents are 9 to 295 ppm in ores and 85 to 2,660 ppm in sphalerite. Analytical results show that the ore-forming fluid of this deposit contains 0.8–3.5 ppm In and 4–36 ppm Sn, and the two elements show a very good positive correlation with a correlation coefficient of 0.8672, while the correlation between In and Zn in the ore-forming fluids, with a correlation coefficient of 0.5723, is not as good as that between In and Sn. This indicates that indium has an affinity with tin in the ore-forming fluids. The authors think that this is probably the main reason why those In-rich deposits spread over the world are simultaneously enriched in tin.  相似文献   

日本自然灾害现状与新态势   总被引：3，自引：0，他引：3  

毛德华  何梓霖  秋山道雄 《世界地理研究》2006,15(2):41-47

日本是一个多灾且严重的国家,依据最新资料,分析了日本自然灾害的现状特征;自然灾害影响社会经济发展,而社会经济变化可能成为新的致灾因素并形成新的灾害形式。本文特别对城市化、过疏化、高龄化和网络化与灾害进行了论述;最后论述了“自助”“共助”和“公助”三位一体的防灾基本对策的内容。这些对正处于高速经济发展和城市化的我国来说,具有重要的借鉴作用。  相似文献   

Mineral and fluid inclusions in zircon of UHP metamorphic rocks from the CCSD-main drill hole: A record of metamorphism and fluid activity   总被引：18，自引：0，他引：18  

Zeming Zhang  Kun Shen  Yilin Xiao  Jochen Hoefs  J.G. Liou 《Lithos》2006,92(3-4):378-398

The Chinese Continental Scientific Drilling (CCSD) main drill hole (0–3000 m) in Donghai, southern Sulu orogen, consists of eclogite, paragneiss, orthogneiss, schist and garnet peridotite. Detailed investigations of Raman, cathodoluminescence, and microprobe analyses show that zircons from most eclogites, gneisses and schists have oscillatory zoned magmatic cores with low-pressure mineral inclusions of Qtz, Pl, Kf and Ap, and a metamorphic rim with relatively uniform luminescence and eclogite-facies mineral inclusions of Grt, Omp, Phn, Coe and Rt. The chemical compositions of the UHP metamorphic mineral inclusions in zircon are similar to those from the matrix of the host rocks. Similar UHP metamorphic P–T conditions of about 770 °C and 32 kbar were estimated from coexisting minerals in zircon and in the matrix. These observations suggest that all investigated lithologies experienced a joint in situ UHP metamorphism during continental deep subduction. In rare cases, magmatic cores of zircon contain coesite and omphacite inclusions and show patchy and irregular luminescence, implying that the cores have been largely altered possibly by fluid–mineral interaction during UHP metamorphism.

Abundant H₂O–CO₂, H₂O- or CO₂-dominated fluid inclusions with low to medium salinities occur isolated or clustered in the magmatic cores of some zircons, coexisting with low-P mineral inclusions. These fluid inclusions should have been trapped during magmatic crystallization and thus as primary. Only few H₂O- and/or CO₂-dominated fluid inclusions were found to occur together with UHP mineral inclusions in zircons of metamorphic origin, indicating that UHP metamorphism occurred under relatively dry conditions. The diversity in fluid inclusion populations in UHP rocks from different depths suggests a closed fluid system, without large-scale fluid migration during subduction and exhumation.  相似文献   

北极苔原新奥尔松地区的地表辐射特征   总被引：2，自引：0，他引：2       下载免费PDF全文

邓海滨  陆龙骅  卞林根 《极地研究》2006,18(4):254-264

利用我国北极黄河站所在地,德国Koldewey站1993-2003年的资料,对新奥尔松地区的地表辐射特征进行了初步分析。结果表明,由于云的影响,新奥尔松极昼期间的日照百分率仅为32.2%。暖季由于下垫面地表冰雪融化,地表反射率迅速减小,地面吸收辐射和地面有效辐射都迅速增大。全年累计的净辐射为正值;暖季是接受太阳辐射能的主要时段,寒季接受的太阳辐射能极少。虽近10年来新奥尔松地区的气温增加十分显著,但各辐射量的变化趋势不明显。地表辐射实测值与同期NCEP/NCAR相邻格点逐日资料的比较表明,NCEP资料对各辐射项模拟的精度不高。  相似文献   

快速城市化过程中城市土地覆被的时空动态特征     

龚建周  夏北成 《福建地理》2006,(4)

1990~2005年间,是广州市经济快速发展和城市景观变化最大的时期,以同时段TM影像解译得到广州市的土地覆被类型图,从数量结构、空间信息及位置转移和景观等方面,分析了广州市土地覆被的动态特征.数量结构的研究结果显示:在快速城市化过程中广州市的耕地、林地等自然资源的利用程度在加大,自1995年起,这种变化的趋势开始减缓;土地覆被类型之间的信息与位置的转移变化频繁,并且表现出空间位置分异的特征.景观特征指数分析结果表明:广州市城市土地覆被向破碎化方向发展,城市建设用地呈扩展之势.  相似文献