Classification of Mineral Resources Associated and Accompanied with Coal Measures     

YUAN Guotai  HUANG Kaifen China National Administration of Coal Geology  Zhuozhou  Hebei 《《地质学报》英文版》2000,74(3):717-720

The paper discusses the concept of mineral resources associated with coal measures. A rational and scientific classification of such mineral resources becomes more necessary with the development of science and technology. A classification scheme is proposed based on compositions and physical properties and the utilization of these associated minerals.  相似文献   

江苏金坛新石器时代环境变迁研究   总被引：9，自引：0，他引：9  

张强  朱诚  宋友桂 《海洋地质与第四纪地质》2000,20(3):91-99

对江苏金坛三星村新石器遗址ＪＳ９８Ｔ０８２０号探坑南壁剖面进行采磁,对样品帮了粒度、地球化学、孢粉、微体古生物（有孔虫和介形类）等环境替代指标的测定与分析,并据此初步研究和恢复了该区新石器时代古定变状况,得出以下几点认识：（１０地球化学分析结果本区知全新世以来,气候有从暖湿向干冷变化的总趋势。（２）Ｐ２Ｏ５的含量在马家浜墓葬层和崧泽文化层可达生土层的５～６倍,充分反映了当时人类活动日益频繁,同时也  相似文献   

The orbit of the nearby low-mass binary Gliese 600     

A. A. Tokovinin  Yu. Yu. Balega  K.-H. Hofmann  G. Weigelt 《Astronomy Letters》2000,26(10):668-671

We have computed a combined spectroscopic-interferometric orbit for the nearby binary Gliese 600 discovered by us. The orbital period is 2.78 years, and the semimajor axis is 100 mas (0.1″). Its M0 V components are almost identical and have a mass of 0.5M _⊙. The mass ratio is uncertain because of the low radialvelocity semiamplitude (7 km s^?1) associated with the low orbital inclination (37°). The orbital parallax of the binary (52±11 mas) matches its dynamical and photometric parallaxes but differs significantly from the Hipparcos parallax (44.3±1.6) mas; the latter was probably distorted by the orbital motion that was not taken into account.  相似文献   

A laser beacon for monitoring the mesospheric sodium layer at La Palma     

L. Michaille  A. D. Cañas  J. C. Dainty  J. Maxwell  T. Gregory  J. C. Quartel  F. C. Reavell  R. W. Wilson  N. J. Wooder 《Monthly notices of the Royal Astronomical Society》2000,318(1):139-144

We report the results of the first laser beacon experiment at the astronomical site of La Palma (Canary Islands). A continuous wave low‐power laser (a few hundred mW) system has been set up. The laser, tuned on the sodium D₂ line at 589 nm, is launched close to the zenith angle. The emission of the mesospheric sodium layer is observed from a telescope located 160 m away from the laser. The layer is therefore resolved in altitude and the different features of its dynamics are investigated.  相似文献   

中国旅游资源分类系统与类型评价   总被引：153，自引：5，他引：148  

郭来喜  吴必虎  刘锋  范业正 《地理学报》2000,55(3):294-301

旅游资源是旅游业可持续发展的物质基础和旅游生产力增长的潜力所在。作为国家普查规范和技术导引,旅游资源普查必然依据一定的分类系统,通过不同类型地域的实践,在《中国旅游资源普查规范》（试行篇）基础上,新拟的旅游资源分类系统完善分类分级分态系统,工增加到３个景系,１０个景类,９８上景型。在表征资源单体规模时,以景域、景段、景元三个空间尺度等级来区别,并根据资源所处状态分为已开发态、待开发态和潜在势态三种  相似文献   

中国土地荒漠化分类系统探讨   总被引：31，自引：9，他引：22  

刘淑珍  柴宗新  范建容 《中国沙漠》2000,20(1):35-39

通过对前人研究土地荒漠化类型划分成果的学习消化并结合自己多年对土地荒漠化研究,提出我国土地荒漠化类型划分的原则和分类系统,以主导营力和表现形式为划分指标,不但将全国划分为流水作用、风力作用、化学作用和人为直接作用等4个类型,而且从不同类型中再细分出侵蚀劣地,侵蚀裸岩、裸土,堆积沙砾地,土壤劣化;风蚀劣地,风积半流动沙丘,风蚀裸地,土壤粗化、贫化;次生盐渍化、酸化、碱化地,三废污染,农药、化肥污染;废弃土、石、渣堆积,人工挖掘劣地等13个亚类,并对其分布、特征及形成等作了简要论述。  相似文献   

直方图分组数的确定   总被引：3，自引：0，他引：3  

赵荣军 《物探化探计算技术》1999,21(1):82-88

本文以概率统计知识为基础,提出一种直方图分组数的确定方法,并编制了计算机程序。利用该程序能够快速确定直方图的最优分组数、相应分组的频数序列、频率及累积频率,并且对数据进行正态分布检验  相似文献   

清流玮埔地区花岗岩的时代和岩石序列   总被引：5，自引：0，他引：5  

陈日明  陈兴高 《福建地质》1999,18(1):20-26

清流玮埔岩体曾是福建省印支期代表性岩体之一,出露有一定规模,前人把它作为单一的具片麻状构造黑云母二长花岗岩,在１：５万嵩口坪等４幅侵入岩调查中,全面采用侵入岩岩石谱系调查的新理论和新方法,对该岩体进行详细解体,划分出４１个侵入体,建立７个单元,将其归并为廖武坪序列,玮埔单元,盘兰溪序列,并确定了志留纪,三叠纪和晚侏罗纪３个时期的岩浆活动,在对该岩体的时代划分基础上,对不同时代岩石序列,岩石化学,地  相似文献   

浅谈火山构造的分级分类体系     

陈润生 《福建地质》1999,18(3):135-140

通过对前人有关火山构造分级分类方案的清理,归纳和总结,提出区域性火山构造分级分类体系及组合式火山构造分级分类体系,二者构成了一套较完整的火山构造分级分类系统。区域性火山构造体系划分的理论基础是火山作用的构造属性,火山活动与区域性全球性构造活化有关,共分四级四类;组合式火山构造体系是应用火山构造组合理论,低级火山构造通过并列式或叠置式组合方式,逐级组合归并为高级火山构造的分级分类方法,共分四级十五类  相似文献   

青藏高原多年冻土区地温监测结果分析   总被引：6，自引：0，他引：6  

王绍令  赵新民 《冰川冻土》1999,21(4):351-356

Ground temperatures monitored at four observation sites in permafrost regions on the Tibetan Plateau was analyzed. It was found that the ground temperature at the depth of 12～20 m increased 0.2～0.4 K and the permafrost thickness decreased 4～5 m from the base in Xidatan Site from 1975 to 1989; and the ground temperature at the depth of 6～15 m increased 0.2～0.4 K in Kunlun Pass Site from 1982 to 1997. Contrast observations show that a sand cover, 15～20 cm in depth, can result in a ground temperature decrease of 0.1～ 0.2 K in MS66 Site; and a removal of vegetation can result in a ground temperature decrease of some 0.2 K in Hoh Xil Site. The monitor demonstrates that many factors that control permafrost developing have duality, e.g., sand and vegetation are able to increase or decrease the ground temperature. These factors, in conjunction with permafrost behaviour, play different roles under different conditions. Therefore, it is necessary to study, understand and evaluate permafrost and its engineering geological properties taking the viewpoint of dynamic variation.  相似文献