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1.
长江源区自然环境恶劣,生态脆弱,资源较缺乏,居民生活贫困,区域经济的发展和生态环境的保护面临着严峻的挑战。综合分析源区的现状和有利条件,认为旅游资源具有得天独厚的优势,如果加强基础设施建设,逐渐使牧民从散居到聚居,以旅游业为龙头,带动第三产业的发展,促进居民生活方式的多元化,提高居民生活质量和思想素质,树立环保意识,逐渐摆脱对草地的过分依赖,自觉保护生物多样性,优化和重建生态环境,从而实现人和自然的协调发展,步入可持续发展的轨道。  相似文献   

2.
本文从研究实验室的研究方向,组织和人员,仪器设备和实验条件,国内外交流和合作,主要研究成果,学术活动,学术委员会工作情况,系统介绍本实验室。  相似文献   

3.
中国蛇绿岩的分布、时代及其形成环境   总被引:23,自引:22,他引:23  
中国蛇绿岩分布很广,主要在中国的西部,西南部和北部,中部和南部较少,蛇绿岩形成的时代可分为元古宙,早古生代、晚古生代和中-新生代四个时期,中国元古宙蛇绿岩分布零星。星生宙蛇绿岩主要分布在古亚洲洋,秦祁昆洋,古特提斯洋,新特提斯洋和和环太平洋等5个区域,古亚洲洋蛇绿岩位于塔里木和华北地块之北的中国北方,秦祁昆洋位于塔里木、华北和扬子地块之间,古特提斯洋和新特提斯洋位于中国的西南地区,环太平洋带有东北和台湾的蛇绿岩,中国蛇绿岩的地和玻安岩产出,指示产于消减带之上的构造环境,在这些蛇绿岩中也有MORB产出,可能是弧后盆地环境的,也可能有正常大洋岩石圈碎片的残留。古特提斯蛇绿岩MORB发育,而减少与消减作用有关的岩石组(IAT和玻安岩),推测形成在陆间洋盆环境。  相似文献   

4.
乌鲁木齐城市灾害特征及减灾对策   总被引:1,自引:0,他引:1  
论述了乌鲁木齐城市灾害的主要类型,特征,成因及经济损益分析,并就减灾问题提出预防对策,乌鲁木齐市地处欧亚大陆的中心,东,南,西三面环山,北面是广阔的冲积平原;复杂的地质,地貌和地形,多变的气候,加上脆弱的生态环境,为各种灾害的发生提供了重要条件,乌鲁木齐每年都不同程度地发生各类灾害,随着城市人必集和社会发展,生命线工程,城市基础设施和社会财富的增加,城市灾害所带来的损失和灾难将会以更大的比例增长,因此,研究如何防御和减轻自然灾害和人为灾害对城市的破坏,已成为一个重大的社会问题。  相似文献   

5.
水库洪水调度系统设计与开发   总被引:19,自引:0,他引:19  
郭生练  彭辉等 《水文》2001,21(3):4-7
论述了水库洪水调度系统设计与开发的目标,介绍了洪水预报和水库调度的系统结构和功能,运行环境、关键技术、规范化和标准化设计,提出了解决问题的途径和方法,采用软件编程技术,开发出了先进,实用、可靠和界面友好的应用软件,并已在全国31座水库运行,效果良好。  相似文献   

6.
贵州广顺二叠系化学地层的划分及沉积环境分析   总被引:2,自引:2,他引:2  
南君亚  周德全 《矿物学报》1996,16(2):223-230
本文以贵州省广顺二叠纪坝子头-茶叶剖面作了基准剖面,通过野外观察和室内岩相分析,根据岩石的成岩作用,颜色,微相特征及岩层的厚度和叠置关系,进行了层序的划分。在此基础上,以该剖面59个岩层的17个微量元素(As,B,Ba,Co,Cr,Cu,Ga,Mn,Mo,Ni,Pb,Sn,Sr,Ti,V,Zn和Zr)为变量,用因子分析和群分析进行了化学地层单元的划分,通过化学地层和层序地层划分结果的对比,结合化学  相似文献   

7.
利用扫描电镜和X射线衍射仪对滑坡滑带土的研究   总被引:14,自引:0,他引:14  
利用扫描电子显微镜(SEM)和X射衍射仪(XRD)研究了三峡库区,黄河小浪底等地40个滑坡滑带土的结构及物质组合,指出当滑坡处于滑动阶段时,滑带土表居可见粘土矿物定向排列,普遍可见擦痕(弧型,线型,紊乱型),微裂隙和微空隙发育,微生物较多,当斜坡处于稳定阶段时,岩层软弱带可见粘土矿物无定向排列,表面无擦痕,常见树枝状结构。滑带土的物质组合主要为:蒙脱石,蛭石,伊利石,高岭石,绿泥石,方解石,石英,长石和微生物,而蒙脱石,蛭石和微生物含量是滑坡滑动的一个重要因素。据微结构的变化和物质组合可以分析滑坡的活动次数,活动阶段和形成机理,为滑坡治理和稳定性评价提供依据。  相似文献   

8.
康滇地区昆阳群和合理群地层构造及找矿靶区研究   总被引:1,自引:0,他引:1  
戴恒贵 《云南地质》1997,16(1):1-39
笔者在前人工作的基础上,对云南东部“昆阳群”和四川西昌-会理-会东地区的“会理群”进行探讨,采以点,线,面相结合,岩石地层学,生物地层学和同位素代学相结合的工作方法,研究了这套地层所层序,划分和对比问题,然后分析区域构造特征和展布格局,特别强调逆冲推覆断裂的重要性,最后,对成矿规律和找矿靶区提出一些新认识和新看法。  相似文献   

9.
本文从“研究内容和研究方向,学术思想,科研成果和学术水平,研究生培养,国际交流和对外开放,人员和设备条件,实验室机构”七个方面详尽介绍国家地质灾害防治与工程地质环境保护专业实验室。  相似文献   

10.
按照中央的部署,2006年建设工作的总体要求是以邓小平理论和“三个代表”重要思想为指导,认真贯彻党的十六大、十六届五中全会和中央经济工作会议精神,坚持用科学发展观统领全局,继续落实中央宏观调控政策措施,加快改革和创新,转变城镇发展模式,整治村容村貌,提高城镇化发展的质量和效益,努力改善居民住房、交通和环境条件,促进社会和谐,为顺利实施“十一五”规划开好局、起好步。要坚持用发展和改革的办法解决前进中的问题,扎扎实实地做好各项工作。  相似文献   

11.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

12.
13.
Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.  相似文献   

14.
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.  相似文献   

15.
从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返   总被引:4,自引:1,他引:4       下载免费PDF全文
位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压,而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩,榴辉岩及其他直接围岩皆呈包体存在于其中,并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体,表明新元古代花岗岩的组成物质也经受过超高压变质作用,且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次(或阶段)却少于榴辉岩。椐上述可得如下推断:超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部(俯冲板块前部)形成的;榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的,其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升,遭受剥蚀。  相似文献   

16.
某高速公路下伏煤矿采空区稳定性分析   总被引:10,自引:0,他引:10  
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。   相似文献   

17.
摩擦桩基桩土间极限摩阻力取值问题探讨   总被引:1,自引:0,他引:1  
陈银生 《世界地质》1999,18(1):54-59
通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。  相似文献   

18.
19.
The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.  相似文献   

20.
We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.  相似文献   

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