相似变换在大比例尺地形图的投影换带中的应用

在大比例尺地形图的使用过程中，会遇地形图的坐标系变换，需要把中央子午线为L1的坐标系的地形图转换成中央子午线为L2的坐标系的地形图，称之为地形图投影变换。目前许多地形图是以电子地图形式存在的，是通过AUTOCAD软件形成的。基于此，本文提出了适用于AutoCAD中地形图投影换带的方法：相似变换法。即在满足精度要求的情况下，利用相似变换原理，对AutoCAD中的地形图进行平移，旋转，缩放变换，最终将其变换到需要的坐标系内。     

陕西八卦庙金矿床NE向黄铁矿-石英成矿期成矿物质来源和成矿机制探讨:原位硫同位素证据

八卦庙金矿床位于秦岭造山带凤太铅锌多金属矿田北部,是陕西省规模较大的金矿床之一,已探明金储量约106 t.赋矿围岩是上泥盆统星红铺组浅变质泥质碎屑岩和碳酸盐岩,其成矿过程可划分为3期,分别是①顺层磁黄铁矿-石英成矿期;②NE向黄铁矿-石英成矿期;③裂隙硫化物-方解石成矿期.目前关于NE向黄铁矿-石英成矿期成矿物质来源和...     

注册测绘师制度实施有关问题研究

注册测绘师制度的实施有利于规范测绘行为,保证测绘成果质量,意义重大。本文针对注册测绘师制度推进过程中遇到的现实问题进行了调查研究。通过问卷和实地访谈,对注册测绘师签字文件种类,测绘资质单位需配备注册测绘师数量,注册测绘师事务所可行性,注册测绘师制度与现行管理项目关系,注册测绘师考试等相关问题进行了研究和思考,并提出了相关的对策建议,供有关方面在推进注册测绘师制度实施时参考。     

贵州铜仁暴雨和冰雹雷达回波特征对比分析

利用铜仁新一代多普勒天气雷达对贵州铜仁区域的局地暴雨和冰雹天气过程的雷达监测常用产品进行对比分析,得出了产生暴雨和冰雹天气时其雷达回波特征的差异性:(1)冰雹回波反射率因子及剖面在较高的高度上维持较大强度,且其剖面通常具有穹窿结构,暴雨回波中通常有多个对流回波柱,强回波核位于云体中下部。(2)局地暴雨天气通常为混合型降水回波的"准静止"状态和长时间的"列车效应",冰雹回波其外形结构多呈点状、块状、带状等特征,有时候还会出现钩状、弓形回波等特殊形状;(3)暴雨径向速度和冰雹径向速度都存在逆风区等特征,短时强降水发生在逆风区边缘地带、径向速度辐合最大的区域。冰雹径向速度变化范围较大,有强烈的风向、风速辐合过程,有时还会伴随中尺度气旋。(4)冰雹回波的垂直液态水含量和回波顶高都比暴雨大,在降雹前2-5个体扫范围内冰雹回波的垂直液态水含量值会出现明显的跳变,而暴雨回波其值比较平稳并且维持较低数值。(5)VWP在冰雹过程中从低层到高层存在垂直风切变,其切变越大,出现冰雹的可能性越大,而暴雨的西风气流风速远小于冰雹过程。     

南海北部新生代的构造运动特征

新生代以来,南海北部陆架陆坡区及其邻区的地壳构造运动是在统一的区域构造应力场和总体区域性张裂沉降背景之下发生的,构造运动具有多旋回振荡式发生的特点,并贯穿了晚白垩世末之后的整个新生代.它的发生与太平洋板块的构造运动密切相关,这是由于太平洋板块之下的软流层流动方向和强度的振荡式改变而引发的.     

中美县级土地整治政策对比研究

通过对比分析美国洛杉矶县住房供应规划中空闲地和低效利用地整治与我国县级城乡建设用地增减挂钩规划中农村空闲地和低效利用地整治在目的、空闲地和低效利用地确定、公共参与、与总体规划关系方面的差异,分析了我国目前县级城乡建设用地增减挂钩规划存在的不足,并进行了讨论。     

武汉遥测台网地震记录中小爆破的判据研究

主要研究武汉地区小当量爆破(即矿山爆破)事件与小震级(ML 2.0左右)地震事件的识别与判据.     

Research on EPS application to very wide highway embankments in permafrost regions

In order to maintain the thermal stability of very wide highway embankments in permafrost regions, the thermal isolation material EPS is often utilized. To examine the effects of this insulation on the China National Highway (G214), two-dimensional finite element analysis of temperature fields was conducted for varying widths of highway embankments with and without EPS insulation. The numerical results show that in permafrost regions the effect of thermal aggregation on asphalt pavement is more obvious when highway embankments are wider, and, specifically for the G214 highway, the insulation should be more than 25 cm thick for 24-m-wide embankments. However, considering other factors such as the structural rationality of the embankments and high engineering costs, it might not be feasible to install EPS insulation in 24-m-wide embankments of the G214 highway when the height of the embankments is less than 3.65 m.     

U-series disequilibria in Kick’em Jenny submarine volcano lavas: A new view of time-scales of magmatism in convergent margins

We present data for U and its decay series nuclides ²³⁰Th, ²²⁶Ra, ²³¹Pa, and ²¹⁰Po for 14 lavas from Kick’em Jenny (KEJ) submarine volcano to constrain the time-scales and processes of magmatism in the Southern Lesser Antilles, the arc having the globally lowest plate convergence rate. Although these samples are thought to have been erupted in the last century, most have (²²⁶Ra)/(²¹⁰Po) within ±15% of unity. Ten out of 14 samples have significant ²²⁶Ra excesses over ²³⁰Th, with (²²⁶Ra)/(²³⁰Th) up to 2.97, while four samples are in ²²⁶Ra-²³⁰Th equilibrium within error. All KEJ samples have high (²³¹Pa)/(²³⁵U), ranging from 1.56 to 2.64 and high ²³⁸U excesses (up to 43%), providing a global end-member of high ²³⁸U and high ²³¹Pa excesses. Negative correlations between Sr, sensitive to plagioclase fractionation, and Ho/Sm, sensitive to amphibole fractionation, or K/Rb, sensitive to open system behavior, indicate that differentiation at KEJ lavas was dominated by amphibole fractionation and open-system assimilation. While (²³¹Pa)/(²³⁵U) does not correlate with differentiation indices such as Ho/Sm, (²³⁰Th)/(²³⁸U) shows a slight negative correlation, likely due to assimilation of materials with slightly higher (²³⁰Th)/(²³⁸U). Samples with ²²⁶Ra excess have higher Sr/Th and Ba/Th than those in ²²⁶Ra-²³⁰Th equilibrium, forming rough positive correlations of (²²⁶Ra)/(²³⁰Th) with Sr/Th and Ba/Th similar to those observed in many arc settings. We interpret these correlations to reflect a time-dependent magma differentiation process at shallow crustal levels and not the process of recent fluid addition at the slab-wedge interface.The high ²³¹Pa excesses require an in-growth melting process operating at low melting rates and small residual porosity; such a model will also produce significant ²³⁸U-²³⁰Th and ²²⁶Ra-²³⁰Th disequilibrium in erupted lavas, meaning that signatures of recent fluid addition from the slab are unlikely to be preserved in KEJ lavas. We instead propose that most of the ²³⁸U-²³⁰Th, ²²⁶Ra-²³⁰Th, and ²³⁵U-²³¹Pa disequilibria in erupted KEJ lavas reflect the in-growth melting process in the mantle wedge (reflecting variations in U/Th, daughter-parent ratios, fO₂, and thermal structure), followed by modification by magma differentiation at crustal depths. Such a conclusion reconciles the different temporal implications from different U-series parent-daughter pairs and relaxes the time constraint on mass transfer from slab to eruption occurring in less than a few thousand years imposed by models whereby ²²⁶Ra excess is derived from the slab.     

对国有地勘单位人力资源管理的对策建议

近年来,国有地勘单位在改革发展中,人力资源管理方面普遍存在职工观念滞后、冗员较多、员工积极性不高、人才流失等问题。以总局管理下的某地勘单位为例,对国有地勘单位人力资源现状及存在的主要问题进行了梳理,总结提出了在当前环境下加强人力资源管理的对策及建议：强化人力资源管理意识,营造适宜人才发展的良好氛围;完善用人机制,加大人力资本投入;实施人力资源综合发展战略,设计合理的人才培训计划;深入体制改革,激发员工创新的积极性。