陕西周户长地区金矿成因初探

陕西周(至)户(县)长(安)金成矿区位于华北板块与扬子板块的结合地带，已发现大型金矿床2处，中小型矿床(点)20余处。它们分属金牛坪-库峪贵、多金属成矿带和沙梁子-丰北河贵金属成矿带。本区金矿成矿物质来源可能与围岩有关；硫来源较为复杂，总体表现为混合硫特征；成矿流体总体表现为混合流体特征；成矿物化环境为中低温、低压、弱酸性的浅部还原条件。本区金矿矿床类型属于蚀变岩型和石英脉型。     

胶东地区裸露含金构造的地球化学评价

为评价裸露含金构造,提出了一种新的地球化学评价方案,包括纵向采样布局和数据解释的对应分类法.用新的采样布局代替常规布局,能以较少的成本获得较多的经济效益,在平度地区以2 439个样品发现了84条有价值的含金构造.对应分类法继承和改善了常规方法,能用较简单步骤和单一图件更有效地揭示数据中的核心信息.在纪山地区,据此单一图件提供了不同元素组合类型、不同地球化学单元类型、单元的等距性、单元的分带性、已知矿单元的各种地球化学特征和靶区等,特别是显示了区内一个典型地球化学分带序列.对应分类法还可用于其它领域.     

Analysis of chlorophyll diagenesis—II. Solvent effects on metal incorporation into chlorophyll diagenetic products

We are attempting to quantify selected transitions in the diagenetic pathway of chlorophyll in deep ocean sediments. To analyze the aromatization from phorbides (less stable) to porphyrins (more stable), we used a model system which closely resembles the compounds identified in oceanic sediments. Kinetic parameters were determined for the incorporation of copper into deoxomesopyropheophorbide a methyl ester (DOMPP) and deoxophylloerythrin methyl ester (DPE) in a series of solvents ranging from highly polar and protic to non-polar and aprotic, representing varying sedimentary environments. In the reaction of copper with these two compounds, the activation parameters for the reaction with DOMPP indicate that DOMPP is more sensitive to the environment than DPE. Also, over the temperature range studied, DOMPP always reacted faster than DPE under similar conditions. These two observations lend support to our previous hypothesis that the phorbide to porphyrin transition includes the metallophorbide as a short-lived intermediate in the reaction sequence.     

国外航空电磁法现状和我国现阶段航电的发展

本文介绍了93航空电磁法国际研讨会概况及国外航电的现状。在分析了我国航电现状的基础上,探讨了我国航电现阶段的发展问题。     

Analysis of chlorophyll diagenesis—I. Kinetics of the phorbide to porphyrin transition

The objective of this project is to quantify selected transitions in the diagenetic pathways of chlorophyll in deep ocean sediments, initially the aromatization from phorbides (unstable) to porphyrins (stable), using a model system which closely resembles the compounds identified in oceanic sediments. We determined the kinetic parameters for the aromatization of deoxomesopyropheophorbide a methyl ester (DOMPP) to deoxophylloerythrin methyl ester (DPE) in the presence of Cu(II) in a series of solvents ranging from highly polar and protic to nonpolar and aprotic, representing varying sedimentary environments. With Cu(II) in ethanol, the aromatization occurs through a pathway which involves a relatively slow initial formation of CuDOMPP, rapid aromatization to CuDPE, and finally an equilibrium reaction in the presence of clay which induces demetalation to form the free base DPE. Based on our model studies, only DOMPP, CuDPE and some DPE would be detected in significant quantities in more polar, protic sedimentary environments on a geologic time scale, although the story might be different with changed environment polarity. Our model studies may ultimately reconcile laboratory observations with those based on DSDP cores which appear to indicate that the diagenetic sequence proceeds from phorbide to free base porphyrin, followed by metalation of the porphyrin.     

Calci-microbialite as a potential source rock and its geomicrobiological processes

The calci-mircobialite is a special carbonate buildup, which is formed due to the activities of different kinds of microbes. Abundant microfossils preserved in the microbialite show the high-level productivity during deposition, while characteristic sedimentary minerals and geochemical compositions suggest an anoxic marine environment for organic burial. The high-level productivity and anoxic sedimentary environment favor the efficient preservation of organic matter and thus the formation of source rocks. On these points, microbialites could be one of the potential hydrocarbon source rocks, awaiting further geobiological investigation and exploration. Precambrian and some of the great transitional stages in Phanerozoic are critical periods when microbialites were well developed. Widespread microbialites have been found in North and South China. Bitumen observed in many outcrops of Precambrian and late Devonian microbialites further raises the possibility of the calci-microbialite as a potential hydrocarbon source rock. __________ Translated from Earth Science-Journal of China University of Geosciences, 2007, 32(6): 797-802 [译自: 地球科学-中国地质大学学报]     

沉降观测周期的确定方法

本文结合实例介绍了沉降观测周期的简便确定方法，并提出了特殊情况下确定沉降观测周期的不同方法。     

最短路径算法的改进方法研究

研究了最短路径算法的改进方法,主要体现在数据结构方面的改进,实现了Dijkstra和A*两种原始算法,在限制搜索区域方面实现了矩形限制区域、限制方向和基于层次搜索机制,通过比较得到了实际应用中非常有用的一些结论.     

估算异性岩石不连续面峰值剪切强度的经验公式

长江三峡库区广泛发育着两侧岩性不同的不连续面（称为异性不连续面）,研究其峰值剪切强度可为相关岩体的稳定性分析和评价提供理论依据。采用高强石膏浇注3组不同形貌且上、下壁面强度不同的不连续面试件,并在不同常法向应力下进行剪切试验。引入不连续面壁组合系数λ来综合量化不连续面壁的抗压强度和基本摩擦角对异性不连续面峰值剪切强度的影响,λ越小,上、下不连续面壁强度差异越大。异性不连续面的峰值剪切强度随λ的增加呈非线性增加,且在高法向应力下更为显著。在Barton公式的基础上,通过多元回归分析建立了估算异性不连续面峰值剪切强度的经验公式。采用天然和人工锯齿形异性不连续面的直剪试验结果对新公式做了进一步验证,试验剪切强度与新公式预测值吻合较好。简要分析了新公式在软硬互层岩质边坡稳定性评价中的应用。最后,讨论了Wu公式的适用性以及新公式的优点和不足。     

基于图像分割的地铁隧道渗漏水快速检测

地铁隧道具有线路长、地质环境复杂、环片数量多、检测作业时间短等特点.隧道结构渗漏水病害检测是保障地铁隧道安全的重要工作,传统人工巡查检测方法检测速度慢,需耗费大量的人力物力,不能满足地铁更好运营需求.为提高隧道渗漏水检测效率,更好地适应轨道交通运营需求.本文依托高速移动三维激光扫描技术获取点云数据,提出局部图像分割方法,获取隧道渗漏水病害信息.首先通过空间变换法将三维点云数据转换为二维正射影像,采用图像二值化处理算法增强隧道渗漏水病害区域的边缘信息;然后利用区域描述算法对图像内的渗漏水区域进行分析,获取渗漏水病害区域的大小和里程信息,从而达到自动化识别隧道结构病害.研究结果表明,本文方法可快速检测地铁隧道内渗漏水病害的位置、面积等信息,节约检测时间和检测成本的同时保证了检测结果的准确性.