天文经纬度归心实用算式推证

文中分析天文经纬度归心公式中各变量的特点,推导基于2000国家大地坐标系统简单实用的归心计算公式,进一步给出由已确定变量推求归心元素测量精度的数学关系式。验证实用公式计算的归心改正数满足专用工程天文经纬度的计算精度需求。     

工业构件密集点云数据与CAD模型的配准

针对工业构件人工检测安装效率低的问题,该文提出基于三维激光扫描的点云数据与CAD模型的配准方法。该方法是预先在两模型中找出公共点进行粗配准,把粗配准后的两模型用迭代最近点(ICP)算法进行精确配准,并通过提取公共特征点进行匹配的精度检测。实验表明,通过该方法实现了点云与CAD模型的配准,有效地提高了工业逆安装效率。     

大分子烃类拉曼光谱特征及在烃包裹体研究中的意义

拉曼光谱分析发现,无论大分子烃类含碳数如何不同,分子结构如何复杂,大分子烃类的拉曼谱图有很多相同性,即烃类的拉曼谱图只受烷烃骨架、环烷基和苯环等的影响,并由此形成了四类大分子烃类的拉曼谱图：烷烃类、复杂烷烃类（以环烷基为主）、结构平坦相连的芳香烃类和结构复杂的芳香烃类。烃是石油的主要组分,因此,被包裹在矿物中的石油——烃包裹体的拉曼谱图也只有四种：发强荧光烃包裹体、含沥青烃包裹体、含低碳数芳烃包裹体和烷烃包裹体。激光拉曼对烃包裹体组分有个总体特征的体现,用激光拉曼分析烃包裹体组分中具体烃的种类是不科学的。但通过烃包裹体的拉曼谱图特征,可以研究烃包裹体组分特征、古油藏成熟度及油气演化程度等信息。     

振动切喷技术在重庆草街航电枢纽工程中的应用

在振动切刀下部安装有定喷的喷嘴,振动切槽之前,超前进行定喷,将振动切槽与定喷两种工艺综合成一种工艺,构成一种新的薄防渗墙的施工工艺——振动切喷技术。介绍了该新技术在重庆草街航电枢纽工程中的应用情况,实践证明,此工艺提高了防渗墙的施工效率与成墙质量。     

利用叠前地震数据预测火山岩储层裂缝

通过对叠前弹性波阻抗反演及各向异性理论的研究,归纳出一种通过叠前地震数据来预测火山岩裂缝的方法思路:首先引入叠前弹性波阻抗反演,利用其分辨率高的优点来寻找火山岩储层,然后分析裂缝引起的地震波动力学属性随方位角的变化特征,通过各向异性来预测裂缝的方向和发育程度,综合判断火山岩储层裂缝的分布情况。该方法以"面向储层找裂缝"为原则,在分辨率和预测准确性上都有其理论优势,将该思路在试验区域进行尝试,取得了较好的效果。     

泌阳凹陷下第三系湖相白云岩形成条件

中国中、新生代大多数湖盆湖相碳酸盐岩以灰岩沉积为主,但部分湖盆像南-襄盆地泌阳凹陷则主要沉积白云岩,其累计厚度达 90 0余米,而白云岩层系的厚度 (包括白云质、灰质泥岩,白云质粉、细砂岩等夹层 )可达 2 2 0 0m,并成为良好的生油岩系,形成小而肥的南阳油田。本文着重探讨如此巨厚的白云岩形成的古气候、古水体的物理化学性质和古环境条件。在目前湖相碳酸盐岩研究仍处于湖泊沉积学研究的极薄弱领域,湖相白云岩形成条件更是涉及较少的情况下,愿本文的研究能起到抛砖引玉的作用.     

金沙江攀枝花段水系沉积物中重金属的分布特征及污染评价

对攀枝花地区金沙江水系沉积物中九个重金属元素的地球化学特征及空间分布特征进行了分析研究,并对各重金属的污染程度进行了初步评价。研究发现,重金属在支流与金沙江交汇点下游处含量高于上游处,这说明金沙江有一定的自净化能力。通过分析可知,重金属的污染程度为:Cu>V>Ti>Mn>Cr>Zn>As>Co>Pb,其中Cu、V、Ti、Mn污染严重,Pb为轻度污染。污染最严重的地区是攀钢冶金区、攀钢选矿区、攀钢采矿区以及攀钢尾矿坝。     

Deflation rates of different clastic sediments in the arid regions of China

By wind tunnel experiment, we studied the deflation rates of 8 different clastic sediments in the arid regions of China, discussed the sources of aeolian sand and their influence on the development of sand dunes and formation of sand deserts from the view of dynamics of wind erosion. The average deflation rates of 8 typical clastic sediments in the arid regions of China can be arranged in the order of lacustrine sand > alluvial sand > weathered sandstone and shale > pluvial sediments > fluvioglacial sand > weathered granite > slope deposit > glacial sediments. The deflation rates exhibited strong positive correlations with the erodible particle (0.063–2mm) content and sorting features. In contrast, the deflation rates had obvious negative correlations with the contents of silt clay (<0.063 mm) and gravel (>2 mm). According to the deflation rates, the 8 typical clastic sediments can be divided into four categories: (1) lacustrine and alluvial sand, which are readily prone to wind erosion, assumed to be the main source of aeolian sand; (2) weathered sandstone and shale, pluvial sediments and fluvioglacial sand with considerable deflation rates, might be the secondary source of aeolian sand; (3) weathered granite and slope deposit having the lower deflation rates, could supply a little aeolian sand; and (4) glacial sediments with a strong anti-erodibility, could hardly offer any aeolian sand. In addition to the strong wind conditions, the exposure of extensive lacustrine sand induced by the desiccation of inland lake basin, as well as the pre-sorting of clastic sediments by flowing water should be the key factors influencing the development of sand deserts in China. The possible reason the sand deserts in China being mostly distributed around the inland lake basins and along riverbanks could be better understood through sand source analysis.     

NUMERICAL STUDY OF THE ABNORMAL TRACK OF TYPHOON MAGGIE

Typhoon Maggie (1999) interacted with another tropical depression system and moved along a west-southwest track that is somewhat abnormal during its pre-landing stage. Two numerical experiments are carried out in this paper to study the effect of the interaction on the track of typhoon Maggie using the mesoscale numerical weather prediction model system with a tropical cyclone bogusing scheme developed by Center for Coastal and Atmospheric Research, the Hong Kong University of Science and Technology. Results show that the cyclone system interacting with Maggie is the main factor for the abnormal track of Maggie.     

松辽盆地湖相泥岩地层有机碳分布特征及层序分析

松辽盆地湖相泥岩地层中有机碳呈有规律的分布。在纵向上,特定的地层沉积单元常显示出底部有机碳含量高而向上含量逐渐减小的变化趋势。这种变化规律与相对湖平面的升降及沉积物的供给有关,并且可以在电阻率和声波时差叠覆曲线上以不同程度的幅度差表现出来。根据这种叠覆的测井曲线对松辽盆地英台地区嫩江组泥岩地层中的有机质丰度以及地层层序进行了分析。英台地区嫩江组一、二段泥岩地层以嫩一段和嫩二段下部地层的有机质丰度较高。从泥岩层序对比及测井曲线幅度差分析,该时期英台地区沉积物源来自于北部,其南部烃源岩有机质含量要高于北部。以嫩江组为主要烃源岩的黑帝庙油层的勘探也证实了这一点.