首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
人们关注地球深部水对地球介质的力学和物理性质影响,以往实验研究大都用气体设备在几百MPa的低压力下进行的。为实现深部高压条件,本文用固体传压技术在1000-1300℃,1.0-2.0GPa温压条件进行橄榄石晶体内水溶解度实验研究。  相似文献   

2.
上地幔橄榄岩流变性研究新进展及其地球动力学意义   总被引:2,自引:1,他引:2  
本文系深部地幔流性研究进展综述文章之一,重点介绍了近年来国际地球物理学界在涉及橄榄岩上地幔流变性的下述三方面取得的进展:(1)化学环境因素对橄榄石高温塑性的影响;(2)高温高压下水在橄榄石晶体中的溶解度和赋存状态;(3)橄榄石多晶体的变形机制转变,并对由此得出的地球动力学意义作了讨论。  相似文献   

3.
固体传压高温高压岩石三轴实验中,固体传压介质是影响实验结果的重要因素,NaCl介质以它流动性好,围压均匀等特点,八十年代以来越来越受到人们青睐。本文用NaCl介质在〈3GPa固体传压三轴流变仪〉上进行了高温高压岩石流变特性的实验研究,并达到了较高的压力(〉2GPa)和温度(〉1200℃);本文同时利用NaCl介质对样品装样方式及温度、压力等相关测定方面进行了研究。  相似文献   

4.
高温高压实验是探索地球深部奥秘的重要手段,金刚石压腔(Diamonnd Anvil Cell,DAC)作为一种静态超高压实验装置,目前能够达到的温压条件可以涵盖整个地球范围.近年来,随着实验技术的发展和实验装备的不断改进,DAC可以与多种物性测量方法相结合,在模拟地球深部温度和压力的条件下,原位获得有关地幔矿物的物性数据.本文首先介绍了金刚石压腔装置及其特点,然后重点阐述了近五年来DAC在典型地慢矿物物性研究方面取得的进展:(1)水在橄榄石、辉石中的结合方式及其影响;(2)组成成分变化对橄榄石、石榴子石、斯石英、钙钛矿等矿物物性的影响.文章最后对金刚石压腔装置的改进,特别是压砧的发展进行了探讨.  相似文献   

5.
介绍“3 GPa固体传压三轴流变仪”的结构、性能及其实验方法与用途,阐述在此设备上进行的关于深部(上地幔高温高压条件下)岩石流变特性的实验以及岩石蠕变.应力松驰现象的研究.  相似文献   

6.
高压下岩石弹性波速度几种测量方法的比较实验研究   总被引:2,自引:0,他引:2  
在高压高温条件下测量岩石弹性波速是获得岩石在地球内部的各种力学和热力学数据的主要途径, 也是研究地球内部物质结构和组成的重要手段. 近年来, 用固体作为传压介质的高压高温岩石弹性波速测量方法发展较快, 然而目前各个实验室在高温高压条件下所测量出的岩石弹性波数据, 还没有进行过严格的对比. 为了对比各实验室的实验测量结果, 对3种测量方法进行了比较实验研究, 并与流体传压介质透射法的测量结果进行了对比. 实验表明, 3种测量方法在其适用压力范围内的测量结果都能相互对比. 其中Kern所使用的六面体样品脉冲透射法适用于压力温度较低的地壳类岩石样品的测量. 柱状样品脉冲反射-透射法在适用压力范围、加热温度和测量精度方面均有一定优势. 柱状样品脉冲透射法虽然在压力较低时测量精度较低, 但样品长度大, 组装简便, 适用于样品量大, 要求压力较高的实验. 因此在实际应用中, 后两种方法可进行相互校正和相互补充.  相似文献   

7.
人们对上地幔标志性矿物橄榄石的认识,基本上是经历一个从直流到交流,又从交流到阻抗谱的认识过程.本文主要通过对橄榄石电导率的影响因素出发,包括温度、压力、铁镁比值、氧逸度等因素的影响和制约.用目前国际高温高压学术界公认的阻抗谱技术探讨了橄榄石在高压下的相变,并在此基础上,进一步研究地球物理学家非常关心的热点问题-冷地幔的实验室的模拟,并作了充分的论证.  相似文献   

8.
地幔深部的矿物具有显著的含水能力,含水量从几十到几万ppm(part per million)不等.由于地幔体积巨大,地球深部的水可能远大于地表水的总量.研究水在地幔矿物岩石晶体中的赋存机制及其影响是目前矿物学和地球物理学界的研究热点之一.一方面,俯冲板块向下运动,其中的蛇纹石在高温下分解,产生一系列的高含水硅酸盐矿物(如相A、粒硅镁石和斜硅镁石),这些矿物是潜在的"搬运工",将水进一步带入地幔深部,乃至转换带中;另一方面,橄榄石在转换带中的高压相(瓦兹利石和林伍德石)具有较高的储水能力,使得转换带成为了地球深部最重要的储水层,并且水也对地幔转换带的物理化学性质产生了显著影响.本文主要讨论以下两方面内容:(1)含水的硅酸盐矿物晶体结构,为微观上认识地球深部水的赋存机制和循环过程提供实验依据;(2)水对硅酸盐矿物热力学状态方程的影响,为约束地球动力学过程以及水的影响提供重要参数.  相似文献   

9.
高温高压下弹性波速测量是研究地球深部物质状态、性质和运动等问题的一种重要手段.现今人们认为,脱水是引起地球内部地震波速度异常的主要原因之一(Kern,1982;Ito,1990;Christensen,1989;Popp,Kern,1993;宋茂双等,1996;周文戈,1998;赵志丹等,1996).地球物理、地球化学和岩石学等资料表明,云母、闪石和蛇纹石等含水矿物的脱水作用是地球深部水的主要来源(Ulmer,Tromsdorff,1995;Ito,Tatsumi,1995;Newton,1989).蛇纹石是地幔的主要矿物——橄榄石和辉石的主要蚀变矿物,含H2O量达13%(wt),远远高于其它含水矿…  相似文献   

10.
为了了解含水含铁橄榄石在地球深部的物性变化特征,探讨深部低速层的成因和地球内部结构,应用基于密度泛函数理论(DFT)第一性原理模拟方法,系统的计算了高压下,水和铁组分对橄榄石及其高压多形相(瓦兹利石(wadsleyite,β-相橄榄石)和林武德石(γ-橄榄石,ringwoodite))弹性、体积、相变等物性的影响.  相似文献   

11.
12.
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.  相似文献   

13.
14.
正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and  相似文献   

15.
Foreword     
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.  相似文献   

16.
正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study  相似文献   

17.
18.
Copyright     
  相似文献   

19.
正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases  相似文献   

20.
Dissolved total carbohydrates (DTCH), dissolved free monosaccharides (DFMS), dissolved organic carbon (DOC), biodegradable DOC (BDOC), and humic substances (HS) were measured in White Clay Creek (WCC), a stream in southeastern Pennsylvania Piedmont, USA. Samples were collected over different seasons and under baseflow and stormflow conditions. DOC concentrations ranged from 1.0 to 12.8 mg/L C with the highest concentrations associated with stormflows. Carbohydrates ranged from 0.42 to 12.4 μM and accounted for 2.9 to 12.7% of the DOC. Humic substances represented the major DOC fraction, accounting for 55 to 72% of the DOC pool under all flow conditions. The humic fraction had a lower carbohydrate content (4.4%) than the non-humic fraction of DOC (7.2%). Stormflow DOC was enriched in carbohydrates relative to baseflow DOC, but the percentage of humic-C changed little. Carbohydrates were primarily present as dissolved polysaccharides (55%), but a significant fraction was bound to humic substances (40%), while a small proportion was present as monosaccharides (5%). The major monosaccharides in stream water, listed in order of decreasing concentration, included glucose, galactose, rhamnose, xylose, arabinose, mannose, and fucose. On average (30.6 ± 7.4)% (n = 44) of the stream water DOC was biodegradable, and carbohydrates accounted for 9.9 to 17.7% of the BDOC.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号