煤岩构造变形与动力变质作用   总被引：1，自引：0，他引：1       下载免费PDF全文

琚宜文  林红  李小诗  范俊佳 《地学前缘》2009,16(1):158

煤岩是一种对温度、压力等地质环境因素十分敏感的有机岩,地质演化过程中的各种构造-热事件必然导致煤岩发生一系列物理与化学结构的变化,并形成不同类型的构造煤。在构造应力作用下,煤岩不仅发生脆性和韧性变形,而且还产生不同程度的动力变质作用。因而,关于煤岩构造变形与动力变质作用的研究不仅具有重要的科学意义,而且在煤层气资源评价以及煤与瓦斯突出危险性预测方面也具有重要的实际意义。文中在已有研究成果基础上,通过对构造煤系列Ro,max、XRD和NMR(CP/MAS+TOSS)等测试和实验方法的对比研究,深入分析了煤岩不同构造变形和动力变质特征,进一步探讨了构造应力下煤岩动力变质作用的机理。研究成果表明,在构造应力作用下,煤岩脆性变形主要是通过破裂面上快速机械摩擦转化为热能而引起煤岩化学结构与其成分的改变;而韧性变形煤主要是通过局部区域应变能的积累而引起煤岩化学结构的破坏,从而发生不同机制的动力变质作用。  相似文献   

The influence of volcanism on paleoclimate in the northeast of China： Insights from Jinchuan peat, Jilin Province, China   总被引：3，自引：0，他引：3  

Xumei Mao  Shenggao Cheng  Yetang Hong  Yongxuan Zhu  Fenglin Wang 《中国地球化学学报》2009,28(2):212-219

Just like contemporary sediments, peat itself is a good repository of information about climate change, the effects of volcanic activity on climate change have been truly recorded in peat, since it is a major archive of volcanic eruption incidents. A section of sand was identified as tephra from the Jinchuan peat, Jilin Province, China, for the grains look like slag with surface bubbles and pits, characterized by high porosity, and loose structure with irregular edges and corners. According to the peat characteristics of uniform deposition, the tephra was dated at 2002–1976 a B.P. by way of linear interpolation, so the time of volcanic eruption was 15 B.C.–26 A.D. (the calibrated age). While the geochemical characteristics of tephra in this study are quite the same as those of tephra from the Jinlongdingzi volcano at Longgang and from alkaline basaltic magma, with the contents of SiO₂<55%, and the similar contents to Al₂O₃ and Fe, but the contents of Na₂O>K₂O. We speculated that the tephra in this study came from the Longgang volcano group. Compared with 11 recorded volcanic eruption events as shown on the carbon and oxygen isotope curves of the Jinchuan peat cellulose, it is obviously seen that adjacent or large-scale volcanic eruptions are precisely corresponding to the minimum temperature and humidity. It seems that these volcanic eruptions indeed affected the local climate, leading to the drop of regional temperature and humidity. As a result, there was prevailing a cold and dry climate there, and all these changes can be well recorded in peat. So the comparison of volcanic eruption events with information about climate change developed from peat, can provide strong evidence for the impact of volcanism on climate change.  相似文献   

Aerodynamic Characteristics of the Crest with Membrane Attachment on Cretaceous Pterodactyloid Nyctosaurus     

WU Jianghao  LU Yi  Lü Junchang  JI Qiang 《《地质学报》英文版》2009,83(1):25-32

The Nyctosaurus specimen KJ1 was reconstructed under the hypothesis that there is a membrane attached to the crest; the so-called headsail crest. The aerodynamic forces and moment acting on the headsail crest were analyzed. It was shown that KJ1 might adjust the angle of the headsail crest relative to the air current as one way to generate thrust (one of the aerodynamic forces, used to overcome body drag in forward flight) and that the magnitude of the thrust and moment could vary with the gesture angle and the relative location between the aerodynamic center of the headsail crest and body’s center of gravity. Three scenarios were tested for comparison: the crest with membrane attachment, the crest without membrane attachment and the absence of a cranial crest. It was shown that the aerodynamic characteristics (increasing, maintaining and decreasing thrusts and moment) would have almost disappear in flight for the crest without membrane attachment and was non-existent without the cranial crest. It is suggested from aerodynamics evidence alone that Nyctosaurus specimen KJ1 had a membrane attached to the crest and used this reconstructed form for auxiliary flight control.  相似文献   

动态分段思想在MapInfo中的实现   总被引：13，自引：0，他引：13  

赵玲  谢树春  汤井田 《测绘学报》2005,34(2):175-178,184

动态分段是一种新的线性特征的动态分析、显示和绘图技术.目前该技术已经成功地应用在以Arc/Info为代表的采用"弧段-结点"数据模型的GIS软件中,但是在采用"面向实体"数据模型的GIS软件中实现动态分段的研究却很少.本文在分析Arc/Info中动态分段数据结构的基础上,探讨如何在MapInfo中实现动态分段思想.  相似文献   

面向对象的三维动态实物模型建模技术     

童晓冲  吴云东  汪滢 《测绘工程》2005,14(3):50-53

总结了面向对象三维建模思想,对模型的组成、结构和框架进行了详细的分析,提出了面向对象的三维动态模型的概念,并建立了模型的数据构成方式,还在此基础上对此结构进行了简化,对由此数据结构产生的文件进行了深入系统的剖析,并给出了实验系统的演示效果.  相似文献   

RADARSAT影像在土地利用动态监测中的应用     

曹银璇  张继贤  燕琴  赵争 《测绘科学》2005,30(4):57-59

为了改变以往土地管理部门对土地管理的传统方式,节省在常规管理中耗费的大量人力和物力,遥感技术作为新兴发展的科学技术,已应用于动态监测土地利用的变化。本文将具体论述如何利用微波遥感技术监测土地利用的动态变化。  相似文献   

广义非线性动态处理模型及其解算方法   总被引：2，自引：2，他引：0  

李述山  陶华学 《测绘科学》2005,30(5):20-21

本文针对当今各国高层领导和科学家十分关注并大力倡导的“数字地球”、“数字国家”、“数字城市”、“数字矿山”等科学工程构建中遇到的大量的多源、多维、多类型、多时态、多精度并具有非线性特征的联合数据处理问题的特点,建立了一个广义非线性动态联合数据处理模型及其相应的广义非线性最小二乘模型。针对该模型规模大、维数高的特点,借鉴多变量函数寻优的“变量轮换法”或“因素交替法”的思想、结合无记忆牛顿法,建立了一个解算算法,该算法将大规模的优化问题分解为两个较低规模的优化问题进行解算,降低了问题的规模,借助无记忆牛顿法,减少了存储量,特别适合大规模问题的解算。  相似文献   

土地利用动态遥感监测数据库标准探讨   总被引：3，自引：1，他引：2  

马晶  曹银璇  燕琴 《测绘科学》2005,30(5):100-101

为了将土地利用动态遥感监测技术和成果进一步普及和应用,规范土地利用动态遥感监测数据库建设,依据国土资源信息化标准建设的总体部署和要求,参考相关标准和规程,结合土地利用动态遥感监测业务特点,制定了土地利用动态遥感监测数据库标准草案。  相似文献   

远洋渔船动态监控系统研究   总被引：5，自引：0，他引：5  

季民  靳奉祥  李云岭  邵全琴 《测绘科学》2005,30(5):92-94

针对远洋渔业生产中的渔船监控问题,以卫星通讯、GIS、GPS、数据库等技术手段为支撑,进行了远洋渔船GPS动态监控系统的研究和开发工作。本文在介绍了系统总体框架的基础上,系统阐述了通讯文件的解包和数据质量的控制过程,并对渔船的动态监视和轨迹分析功能进行了论述。  相似文献   

乳头状肾细胞癌的CT表现与手术病理对照     

邹建华  郑巧  陈伦刚  陈文  付传明 《CT理论与应用研究》2013,(4):693-698

目的：分析乳头状肾细胞癌的cT影像,探讨其相对特异的CT表现。方法：回顾性分析10例经病理证实的乳头状肾细胞癌的临床、手术及CT资料。结果：全部病例均为单发肿块,位于右。肾7例,位于左肾3例,CT平扫肿瘤呈圆形或椭圆形,边缘清楚或欠清楚。病变长径1．0～4．5cm,平均2．5cm。瘤体小时（冬3cm）密度较均匀,无囊变和坏死：瘤体较大时（≥3cm）常出现坏死、囊变。肿瘤强化程度较低,三期呈渐进性轻度增强,特别是排泄期密度略降低。结论：与其他亚型。肾癌相比,乳头状肾细胞癌的cT表现有一定特征,多呈渐进性轻度强化,其确诊可为手术方式的选择提供依据。  相似文献