共查询到20条相似文献，搜索用时 93 毫秒
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青藏高原综合观测研究站的回顾与展望 总被引：1，自引：1，他引：0
中国科学院青藏高原综合观测研究站从１９８８年建站到１９９８年以来,在各个方面均取得了长足的发展,横向生产性项目的开展和完成不仅解决了部队和地方的实际问题,而且缓和了观测研究站在运行过程中所面临的经费严重不足的问题,同时也为我所冻土专业研究人员提供了在生产中实践的机会,在基础理论研究方面,承担了国家攀登计划项目,国家基金项目,中国科学院重点项目和中国科学院冰冻圈专项项目等的研究工作,在多年冻土变化, 相似文献
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根据新提供的Pb同位素组成及岩石地球化学研究成果，本文进一步证实了位于北秦岭北界的明港地区发育的早中生代安山玄武质火山角砾岩岩筒所携带的下地壳捕虏体属于南秦岭。所恢复的南秦岭下地壳剖面自下而上为：底侵成因的变辉长岩-基性麻粒岩(其中含有榴辉岩及辉石岩的透镜体)-酸性麻粒岩。秦岭造山带总体的岩石因模型为：南秦岭(扬子块体)向北拆离俯冲，北秦岭地壳向华北仰冲，华北岩石因呈楔状插入秦岭造山带，拆离面约在中、下地壳之间。南秦岭俯冲岩片延伸的范围在平面上有可能达到400km。 相似文献
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E. M. Korobova 《Geochemistry International》2017,55(13):1205-1282
In his last lifetime essay, “A Few Words about the Noosphere”, Academician V.I. Vernadsky (1944) wrote that all living organisms on the planet, including man, are integral to the biosphere of the Earth, its material and energy structure and cannot be physically independent of it even for a minute. However, the substrate that generates all living beings and is no less tightly bound to the biosphere has always been characterized by a significant geochemical heterogeneity, traced both in the vertical and in the lateral structure of all geospheres.
The present work is devoted to three most important aspects of modern geochemistry and biogeochemistry:
On the basis of theoretical concepts of biogeochemistry and geochemical ecology, formulated in the works of V.I. Vernadsky, A.P. Vinogradov, A.E. Fersman, B.B. Polynov, A.I. Perel’man, M.A. Glazovskaya, V.V. Kovalsky, E. Odum, B. Commoner, E.I. Kolchinskii and others, the author puts forward a hypothesis that there exist two qualitatively different stages in the evolution of the biosphere.The first stage is recognized as the period of natural evolution of the biosphere during which it evolves successively into a more complex and more biogeochemically specialized object. In the course of the geological time, this constantly results, on the one hand, in an increase in species diversity and the perfection of individual species, and, on the other hand, to directed improvement and a greater differentiation of the geochemical conditions of the environment. At this stage, the evolution of all systems of the biosphere that were controlled by the mechanisms of self-organization and self-regulation resulted in the establishment of a dynamic equilibrium, which was responsible for the cycling of all essential chemical elements and therefore providing ecologically optimal geochemical conditions in all ecological niches and for all species and biocenoses inhabiting the biosphere at any given moment.The beginning of the second stage is related to the appearance of reason and qualitative changes in the biosphere caused by the goal-directed activity of the human mind, as an entirely new geological force that appeared to be able not only to disrupt the functioning of natural mechanisms of self-regulation and selforganization, but also to transform the environment in the intersts of a single biological species, Homo sapiens. A direct consequence of this change was the uncontrolled transformation of the natural environment, during which the primary structure (geochemical background) created in the course of billions of years was eventually superimposed by a qualitatively new layer of anthropogenically-derived chemical elements and compounds, thus building an interference pattern of a new geochemical field with which practically all modern living organisms are now forced to interact.An outstanding feature of the new evolutionary stage of the natural environment, called by Vernadsky the noosphere, is that biogeochemical changes at this stage proceed at a rate which exceeds that required for the living matter to adapt to these changes. The result is the disruption of the existing parameters of the biological cycle, leading to the emergence of a significant number of endemic diseases of geochemical nature.The proposed approach was used to prove the anthropogenic genesis of existing geochemical endemic diseases and explain the mechanisms of their appearance. In addition, this approach allowed us to develop a new methodology for mapping zones of ecological and geochemical risk and noticeably simplify the procedure of monitoring distribution and prevention of all diseases of geochemical nature. 相似文献
- — evolution of the ecological and geochemical state of the environment under conditions of a virgin (anthropogenically untouched) biosphere;
- — structural features of the geochemical organization of the modern noosphere;
- — specificity of the interaction of living matter with the environment under increasing anthropogenic load.
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铀钍的地球化学及对地壳演化和生物进化的影响 总被引：10，自引：2，他引：8
本文论述了在含挥发份和贫挥发份条件下Ｕ、Ｔｈ的迁移行为及其对地球和行星演化的影响,并阐述了造成地球独特地质演化历史的原因。提出了Ｕ、Ｔｈ在地球中的迁移模式以及该模式对地壳形成、演化的控制作用和对生物发展演化的可能影响。 相似文献
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利用卫星遥感影像,结合实地调查和测年结果,对共和盆地层状地貌系统进行了解译、分析。研究表明,共和盆地层状地貌系统由山麓剥蚀面、洪积扇面、盆地面以及黄河阶地面构成,其空间结构、物质组成对发生于早更新世早期的青藏运动C幕和中更新世末期的共和运动反映清晰。青藏运动C幕使青藏高原主夷平面在高原差异性隆升中彻底解体,垂直变形量高达1700m。共和运动使黄河在0.11Ma进入共和盆地,其后黄河平均以3.5mm/a的侵蚀速率下切盆地,同时在盆地边部的山前古冲洪积扇以大致相近的速率被抬升,最终导致高差在2000m左右的层状地貌系统的出现。 相似文献
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The experimental variogram computed in the usual way by the method of moments and the Haar wavelet transform are similar in that they filter data and yield informative summaries that may be interpreted. The variogram filters out constant values; wavelets can filter variation at several spatial scales and thereby provide a richer repertoire for analysis and demand no assumptions other than that of finite variance. This paper compares the two functions, identifying that part of the Haar wavelet transform that gives it its advantages. It goes on to show that the generalized variogram of order k=1, 2, and 3 filters linear, quadratic, and cubic polynomials from the data, respectively, which correspond with more complex wavelets in Daubechies's family. The additional filter coefficients of the latter can reveal features of the data that are not evident in its usual form. Three examples in which data recorded at regular intervals on transects are analyzed illustrate the extended form of the variogram. The apparent periodicity of gilgais in Australia seems to be accentuated as filter coefficients are added, but otherwise the analysis provides no new insight. Analysis of hyerpsectral data with a strong linear trend showed that the wavelet-based variograms filtered it out. Adding filter coefficients in the analysis of the topsoil across the Jurassic scarplands of England changed the upper bound of the variogram; it then resembled the within-class variogram computed by the method of moments. To elucidate these results, we simulated several series of data to represent a random process with values fluctuating about a mean, data with long-range linear trend, data with local trend, and data with stepped transitions. The results suggest that the wavelet variogram can filter out the effects of long-range trend, but not local trend, and of transitions from one class to another, as across boundaries. 相似文献
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B. K. Maloney 《GeoJournal》1993,31(4):355-362
While botanists, archaeologists, historians and linguists have contributed to the debate on the origin of the coconut pollen analysts have been silent. This article attempts to integrate the results of recent palaeoecological research with findings from the other disciplines. 相似文献