广西难处理金矿固化焙烧氰化提金试验

通过对广西六梅金矿、明山金矿、金牙金矿含高砷高硫难浸金矿石进行固化焙烧—氰化提金的试验研究 ,获得了砷、硫固定率分别为 99.0 3%、97.0 4 % ,金浸出率 92 .35 %的较好指标 ,为这类难浸金矿的开发 ,展示了一种经济有效的途径     

基于NiosⅡ嵌入式软核处理器的天文用IRFPA图像采集系统

介绍了一套自主研制的用于地基天文望远镜的，基于IRFPA（红外焦平面阵列）图像采集系统，以及所使用的IRFPA原理、性能特点，着重介绍了IRFPA图像采集系统中以NiosⅡ处理器为核心的电子系统的框架结构方案以及软硬件的设计思想。最后给出了初步的图像采集成像结果。     

地理信息的综合集成

古老地理学的新机遇 地理学研究的对象是地理环境。在近代地理学及其以前时期,地理学的研究方法基本上局限于地理环境静态的定性描述,直到本世纪50-60年代兴起计量革命,才开始使地理学的研究方法实现了由静态到动态、由定性到定量、由表象到实质的转变,使地理学在理论和应用上取得了长足的进步。     

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

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.     

An experimental study of the grain-scale processes of peridotite melting: implications for major and trace element distribution during equilibrium and disequilibrium melting

The grain-scale processes of peridotite melting were examined at 1,340°C and 1.5 GPa using reaction couples formed by juxtaposing pre-synthesized clinopyroxenite against pre-synthesized orthopyroxenite or harzburgite in graphite and platinum-lined molybdenum capsules. Reaction between the clinopyroxene and orthopyroxene-rich aggregates produces a melt-enriched, orthopyroxene-free, olivine + clinopyroxene reactive boundary layer. Major and trace element abundance in clinopyroxene vary systematically across the reactive boundary layer with compositional trends similar to the published clinopyroxene core-to-rim compositional variations in the bulk lherzolite partial melting studies conducted at similar P–T conditions. The growth of the reactive boundary layer takes place at the expense of the orthopyroxenite or harzburgite and is consistent with grain-scale processes that involve dissolution, precipitation, reprecipitation, and diffusive exchange between the interstitial melt and surrounding crystals. An important consequence of dissolution–reprecipitation during crystal-melt interaction is the dramatic decrease in diffusive reequilibration time between coexisting minerals and melt. This effect is especially important for high charged, slow diffusing cations during peridotite melting and melt-rock reaction. Apparent clinopyroxene-melt partition coefficients for REE, Sr, Y, Ti, and Zr, measured from reprecipitated clinopyroxene and coexisting melt in the reactive boundary layer, approach their equilibrium values reported in the literature. Disequilibrium melting models based on volume diffusion in solid limited mechanism are likely to significantly underestimate the rates at which major and trace elements in residual minerals reequilibrate with their surrounding melt. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Simple models for dynamic melting in an upwelling heterogeneous mantle column: Analytical solutions

Several lines of evidence suggest that the melt generation and segregation regions of the mantle are heterogeneous, consisting of chemically and lithologically distinct domains of variable size and dimension. Partial melting of such heterogeneous mantle source regions gives rise to a diverse range of basaltic magmas. In order to better assess the role of source heterogeneity during mantle melting, we have undertaken a theoretical study of trace element distribution and fractionation during concurrent melting and melt migration in an upwelling, chemically heterogeneous, two-porosity double lithology melting column. Analytical solutions for the abundance of a trace element in the matrix and channel were obtained under the assumptions that the porosity, melt and solid velocities, and solid-melt partition coefficients are constant and uniform. For simplicity, we neglected diffusion and dispersion in the melt. Chemical source heterogeneities of arbitrary size and shape were integrated into the simple melting models by allowing trace element abundance in the source region to vary as a function of time and space. Concurrent melting and melt migration in an upwelling heterogeneous mantle may be approximated as a quasi-steady state problem in which time-dependent concentration patterns produced by melting of heterogeneous source regions are superimposed on a reference steady-state concentration distribution established by melting of the ambient or background mantle. Chromatographic fractionation is especially important for the matrix melt and solid when chemical heterogeneities are involved during melting and melt migration in the mantle, giving rise to significant phase-shift between two incompatible trace elements in the matrix melt and scattered correlations among incompatible trace elements in residual peridotites. Mixing is the chief mass transfer process in the dunite channel where the chromatographic effect is negligible for most of the incompatible trace elements. The lack of chromatographic fractionation among incompatible trace elements and isotopic ratios in MORB suggests either most MORB are channel melts or mixing in magma conduit and chamber is very efficient such that the phase-shift is averaged out during magma transport and storage processes. Advection brings melt produced by smaller-degree of melting in the deeper part of the melting column to the overlying melting region, increasing the incompatible trace element abundance in the matrix and the channel. This advection-induced self-enrichment is especially important when heterogeneous sources are involved and may account for some of the enriched incompatible trace element patterns observed in residual peridotite that were previously interpreted to be a result of mantle metasomatism. Systematic studies of high-resolution spatially correlated mantle samples may help to constrain the melting history and the size and nature of chemical heterogeneities in the mantle.     

晚三叠世松潘甘孜和川西前陆盆地的物源对比：构造演化和古地理变迁的线索

为了研究龙门山褶皱冲断带两侧的松潘甘孜和川西前陆盆地在大地构造和沉积学方面存在的联系,笔者等分别在松潘甘孜东缘马尔康—理县地区和川西前陆盆地都江堰地区进行了采样和碎屑锆石的LAICPMS UPb定年工作。269颗锆石的定年结果显示,中—晚三叠世拉丁期—诺利期松潘甘孜复理石盆地东缘沉积地层中的碎屑锆石年龄主要集中在250~280 Ma、1800~1900 Ma和2400~2500 Ma、200~245 Ma、400~450 Ma,对应的物源主要为东昆仑岛弧、华北陆块基底、义敦岛弧以及北秦岭。与之相比,川西前陆盆地诺利期—瑞替期的须家河组地层中的碎屑锆石年龄大致主要集中在1800~1900 Ma和2400~2500 Ma、720~850 Ma、950~1200 Ma、400~450 Ma。该统计结果总体上继承了松潘甘孜数据体的特征,揭示出须家河组物源来自西部——松潘甘孜褶皱带的再旋回沉积和龙门山前陆冲断带。     

祁连山近期七一冰川融水径流特征分析

利用2006年8月1日-9月30日的实测水文数据,对"七一"冰川融水径流产汇流特征进行了分析,并揭示出该冰川日消融特征.通过对冰川融水量的估算以及径流模数的计算,并与过去的观测结果进行对比,表明近些年来"七一"冰川消融强度和消融量都在增大,而且2006年消融量为近几年观测的最大值.虽然不同年份消融量不一样,但"七一"冰川总的趋势是一直处于萎缩状态,随着全球变暖,"七一"冰川的萎缩可能将继续下去.通过对设立在沿冰川下游方向两个不同的水文断面进行对比分析,结果表明"七一"冰川融水径流在向下游运动过程中有部分水入渗为河谷潜流,观测期内两个相距不到2 km的水文断面间渗漏损耗占近1/3左右.     

川西108国道高位崩塌成因与运动特征

2007年5月25日于川西108国道某段发生的高位崩塌造成了重大人员伤亡和财产损失。综合地质调查、三维激光扫描技术、爆破振动效应分析以及历史崩塌与降雨关系的统计分析,得出了地形高陡、岩体破碎及降雨诱发等是崩塌产生的主要原因,爆破振动对其也有轻微间接影响。根据边坡形态及塌落高度,运用运动学原理及能量法还对崩塌体的撞击速度及冲击力进行了计算分析。     

南水北调西四环暗涵工程穿越桥梁监控量测技术应用

南水北调西四环暗涵工程为京石段控制性工程,下穿北京市西四环路桥梁30余座,桥梁的安全至关重要。在暗涵施工过程中对桥梁实施了有效的监控量测技术,通过自动化监测和常规监测手段获取数据,然后对监测数据进行详细分析、对比,以研究暗涵下穿桥梁施工过程中桥梁的受力变形协调过程。结果表明:墩柱差异沉降小于允许沉降的80%;墩柱倾斜值小于允许值的30%。监控工作做到了过程预警、过程控制,规避了工程风险,对类似工程具有借鉴意义。