BSZ-2型数字钟的检修方法

BSZ-2型数字钟目前仍应用于模拟地震观测中。本文介绍了该钟的工作原理，并对检修过程中常见问题进行了分析总结。     

泥潭冲金矿床中毒砂标型特征及金的赋存状态

泥潭冲金矿床为主要受近EW向脆-韧性剪切带控制的砷金矿床,是龙王江锑砷金成矿区最具代表性和经济意义的金矿床.文章阐述了矿床地质特征,探讨了载金矿物毒砂的标型特征和金的赋存状态,认为毒砂中的"不可见金"主要为纳米级微粒状的自然金.     

阿尔金北缘大平沟金矿床成因

大平沟金矿是阿尔金北缘地区近年来新发现的一个中型金矿床。它受韧性剪切带构造的控制,矿化类型为蚀变糜棱岩型夹少量钾长石石英脉型。文章通过地质地球化学的研究,探讨了该矿床的成因。稀土元素、硫同位素、铅同位素和锶同位素地球化学特征反映成矿物质主要来源于变质岩;流体包裹体和氢氧同位素反映成矿流体主要来源于变质水,有少量重熔岩浆水和大气降水的混入,成矿温度198～2 90℃,成矿流体密度0 .791～0 .971g/cm3 ;盐度w(NaCleq) =2 .0 3%～5 .5 % ,成矿压力(42 0～72 0 )×10 5Pa ,成矿深度为1.6 1～2 .6 8km。石英流体包裹体Rb_Sr等时线年龄表明成矿时代为加里东期。大平沟金矿床属于中温动力变质热液成因矿床。     

郑州市地热资源热储特征分析

郑州市位于河南省中部,蕴藏较丰富的地热资源.结合地热成因和开发利用情况,郑州市热储划分为断裂型和沉积盆地型,其中沉积盆地型自上而下划分为第一热储层、第二热储层.阐述了各热储层埋藏深度、岩性、水文地质参数、富水性及地下热水循环特征,为地热资源评价提供基础.     

云南中旬普朗、红卓斑岩铜矿床地质特征及找矿前景

通过对印支期普朗、红卓岛弧型斑岩铜矿矿床地质特征和找矿标志的总结，论述了铜矿的找矿前景以及工作方向。     

新疆富蕴县索尔库都克铜(钼)矿床地质特征及成因探讨

矿区内出露地层主要为中泥盆统北塔山组第二亚组,为一套海相、海陆交互相的中基性、中酸性火山岩—火山碎屑沉积岩建造。矿区构造较为复杂,为矿液的运移及铜、钼矿质的沉淀、富集提供了良好的空间条件。Sm-Nd等时线年龄测定显示矿床形成于早二叠世,蚀变岩的Rb-Sr全岩年龄测定结果也反映了成矿和该时期发生的热事件有关。索尔库都克铜(钼)矿床成因应该归属于次火山热液层控型铜(钼)矿床。     

Evaluating some factors that affect feasility of using ground penetrating radar for landmine detection

Ground penetrating radar （GPR） is one of the promising technologies that can be used to detect landmines. Many factors may affect the ability of GPR to detect landmines. Among those factors are： 1） the type of landmine material （metallic or plastic）, 2） conditions of the host soil （soil texture and soil moisture）, and 3） the radar frequency utilized. The impact of these factors on the ability of GPR to detect landmines is investigated by studying their effect on the dielectric permittivity contrast between the landmine and the host soil, as well as on the attenuation of the radar waves. The impact of each factor was theoretically reviewed and modeled using the Matlab and Mathcad software packages. Results of the computer modeling were correlated with GPR data acquired for metallic and plastic landmine types. It was found that the ability of GPR to detect landmines depends to a great extent on the landmine type, water content of the host soil, utilized radar frequency, and soil texture. The landmines are much easier to detect than plastic landmines for any soil conditions and any radar frequency. Increasing the soil＇s moisture content, regardless of soil texture, eases the detection of the plastic landmine and worsens the detection of the metallic mines. Increasing the percentage of clay in the soil causes the same effect as the moisture content. However, higher radar frequency delivers better results for landmine detection as long as the percentage of clay and the moisture content in the soil remains low. The results of this study are expected to help in selecting optimum radar antennae and data acquisition parameters depending on the landmine type and environmental conditions.     

日本强化地震观测网防范首都地震

日本文部科学省日前决定，从2007年起利用5年时间强化覆盖东京及周边地区的地震观测网，详细调查这一区域的地下构造，以防范可能发生的首都直下型地震。     

DTM数据采集的质量控制

数字地面模型（DTM）的建立与实践由数据采集、数据处理与应用3部分组成。数字地面模型是地形表面形态等多种信息的一个数字表达。它是地理信息数据库的基本内核并且有着广泛的应用，DTM数据采集的质量控制，对于DTM的应用来说是一项非常重要的内容。简述了美国丹佛地区数字地面模型（DTM）制作过程中的质量控制要点，以便同大家共同商讨。     

Motorola公司成功地研制出单芯片式的立即型GPS接收机

Motorola和IBM微电子工程师们最近向外界介绍了他们最新研制的立即型GPS接收机,这是一款单片帮助式接收机(A—GPS),目标是应用于移动领域和便携式设备,如PDA设备、数码相机和微型电话上。