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111.
Shyh-Lung?HwangEmail author Pouyan?Shen Hao-Tsu?Chu Tzen-Fu?Yui Juhn?G.?Liou Nikolay?V.?Sobolev Ru-Yuan?Zhang Vladislav?S.?Shatsky Anton?A.?Zayachkovsky 《Contributions to Mineralogy and Petrology》2004,148(3):380-389
Kokchetavite, a new polymorph of K-feldspar (KAlSi3O8), has been identified as micrometer-size inclusions in clinopyroxene and garnet in a garnet-pyroxene rock from the Kokchetav ultrahigh-pressure terrane, Kazakhstan. Kokchetavite has a hexagonal structure with a =5.27(1) Å, c=7.82(1) Å, V=188.09 Å3, Z=1, and is found to be associated with phengite + /-cristobalite (or quartz) + siliceous glass ± phlogopite/titanite/calcite/zircon, occurring as multi-phase inclusions in clinopyroxene and garnet. It is concluded that kokchetavite could not be an exsolution phase in host minerals. Instead, it might be metastably precipitated from an infiltrated K-rich melt during rock exhumation. Alternatively, although less likely, kokchetavite might be derived from dehydration of K-cymrite, which, in turn, was formed at high pressures. In either case, kokchetavite is a metastable polymorph of K-feldspar. 相似文献
112.
滇黔桂盆地及邻区的二叠系包括船山统、阳新统和乐平统。船山统与阳新统之交的黔桂运动主幕不整合面、阳新统和乐平统之交的东吴运动主幕不整合面的不整合特征明显,同时因其代表了研究区沉积盆地性质发生较大变化的界面而成为较为典型的I型层序界面。滇黔桂盆地及邻区的二叠系以其明显的沉积相分异而引人注目:在连陆台地上发育含煤地层,而在连陆台地边缘及孤立台地上发育海绵生物礁,形成一个典型的“台-盆-丘-槽”的古地理格局。伴随着强烈的东吴运动第一幕,研究区西北部发生强烈的火山活动,形成分布范围较广的峨嵋山玄武岩;东南部的“钦防残留海槽”关闭,使研究区的古地理格局发生了较大变化。二叠系与三叠系之交发生的较为典型的台地淹没事件形成了一个较为典型的淹没不整合面。根据沉积物的时间演化序列和沉积相的空间展布形式所指示的规律,研究区的二叠系可以划分为以下三级层序:船山统与下伏石炭系顶部的地层构成一个三级层序(SQ19),阳新统包含四个三级层序(SQ20到SQ23),乐平统包括两个三级层序(SQ24和SQ25)。在层序地层框架内,系列古地理图和系列层序地层格架栅状图较为系统地反映了研究区二叠纪复杂而有序的时间和空间相变特征。主要的时间相变面即形成层序界面,具有明显的“跳相”和地层间断现象,由于在不同地点间断的时限不一致而造成“间断面穿时”;沉积环境的空间变化,以及伴随着时间变化中的相带迁移所造成的空间相变,其相应的相变面总是斜交时间面而造成“相变面穿时”;不同沉积阶段的层序具有不同的相序组构,并在空间上形成有序的变化,从而代表了不同的古地理背景。因此,层序地层研究的核心内容是“沉积物的时间演变序列和沉积相的空间展布形式所代表的规律性”,结合生物地层特征,这种规律性本身也可以作为地层划分和对比的标志。 相似文献
113.
Chung-Lin SHIE Long S. CHIU Robert ADLER Eric NELKIN I-I LIN Pingping XIE Feng-Chin WANG R. CHOKNGAMWONG William OLSON D. Allen CHU 《大气科学进展》2009,26(6):1071-1080
Accurate sea surface flux measurements are crucial for
understanding the global water and energy cycles. The oceanic
evaporation, which is a major component of the global oceanic fresh
water flux, is useful for predicting oceanic circulation and
transport. The global Goddard Satellite-based Surface Turbulent
Fluxes Version-2 (GSSTF2; July 1987--December 2000) dateset that was
officially released in 2001 has been widely used by scientific
community for global energy and water cycle research, and regional
and short period data analyses. We have recently been funded by NASA
to resume processing the GSSTF dataset with an objective of
continually producing a uniform dataset of sea surface turbulent
fluxes, derived from remote sensing data. The dataset is to be
reprocessed and brought up-to-date (GSSTF2b) using improved input
datasets such as a recently upgraded NCEP/DOE sea surface
temperature reanalysis, and an upgraded surface wind and microwave
brightness temperature V6 dataset (Version 6) from the Special
Sensor Microwave Imager (SSM/I) produced by Remote Sensing Systems
(RSS). A second new product (GSSTF3) is further proposed with a
finer temporal (12-h) and spatial (0.25ox0.25o)
resolution. GSSTF2b (July 1987--December 2008) and GSSTF3 (July
1999--December 2009) will be released for the research community to
use by late 2009 and early 2011, respectively. 相似文献
114.
以清洁发展机制(CDM)广西珠江流域治理再造林项目为例,对项目及其5种造林模式临时核证减排量(temporary certified emission reduction,缩写为tCER)和长期核证减排量(long-term certified emission reduction,缩写为lCER)成本的动态变化进行了初步研究。结果表明:从项目期初到期末,整个项目及5种造林模式人工林的tCER成本均逐渐降低,其中项目成本由第一承诺期末的40.33 ¥/t CO2降至最后承诺期末的13.34 ¥/t CO2;lCER成本先降低后升高,在第一承诺期末均降至最小值,项目成本由第一承诺期末的40.33 ¥/t CO2增加至最后承诺期末的105.27 ¥/t CO2;各造林模式tCER和lCER成本均以枫香+杉木、枫香+马尾松较高,马尾松+荷木、马尾松+栎类较低,桉树最低;贴现率对项目tCER和lCER、桉树tCER、枫香+杉木lCER成本影响均较大,而对马尾松+栎类tCER和lCER成本影响均较小;对桉树一个轮伐期内的tCER成本进行了敏感性分析,单位面积碳贮量的变化对其影响较大;考虑木材收益时,项目期末tCER净现值为13.11 ¥/t CO2,从中反映了该CDM项目实施是可行的。 相似文献
115.
我国地面气温参考站点遴选的依据、原则和方法 总被引:17,自引:0,他引:17
由于城市化和观测环境变化的影响,我国现有国家级气象台站网观测的地面气温资料许多已不能满足气候变化检测研究的要求。利用我国全部气象观测站网的台站信息,对地面气温资料序列质量进行了系统评价,遴选出可用于气温变化研究的参考站点。这项工作建立了地面气温参考站点遴选的原则、方法和步骤,并据此确定了138个地面气温参考站。这些台站可代表背景地面气温场,其长期气温观测资料可用作城市台站或国家级台站城市化增温评价的参考,也可直接用于我国地面气温变化的检测分析。 相似文献
116.
Xing Chen Wangsheng Chu Dongliang Chen Zhonghua Wu A. Marcelli Ziyu Wu 《Chemical Geology》2009,268(1-2):74-80
The local and geometrical structure around gold (III) e.g., Au3+ ions in aqueous solution with different OH−/Cl− molar ratios, has been investigated by X-ray absorption spectroscopy (XAS). X-ray absorption near-edge structure (XANES) spectra of [AuCln(OH)4−n]− solutions have been calculated and the multiple-scattering spectral features have been attributed to Cl d-states, axial water molecules and the replacement of Cl− ligands by OH− ligands. A square–planar geometry for [AuCln(OH)4−n]− with two axial water molecules has been identified. Moreover, a spectral correlation between XANES features and the type of planar atoms has been identified. By extended X-ray absorption fine structure spectra (EXAFS), the planar Au bond distances in the solutions have also been determined, e.g., 2.28 Å for Au–Cl and 1.98 Å for Au–O, respectively. The same EXAFS analysis provides evidence that the peak at about 4.0 Å in solutions with the lowest OH−/Cl− molar ratio arises from collinear Cl–Au–Cl multiple-scattering contributions. For the first time, a complete detailed reconstruction of the hydration structure of an Au ion at different pH values has been achieved. 相似文献
117.
118.
119.
2019年12月26日湖北应城发生M4.9有感地震,其震感波及武汉大部分地区。为了分析该地震的发震构造及余震活动性,本文利用波形拟合方法测定了不同速度模型下该地震的震源机制解和矩心深度,并用Bootstrapping抽样反演技术评价反演结果;此外,利用模板匹配技术匹配主震和目录余震波形,获取了更为完整的余震目录。结果显示,应城地震以走滑为主,矩心深度7.5km左右,矩震级MW4.67;应城地震有1个前震和17个余震,余震序列缺少M2~4事件,表明应城地震为孤立型地震,M2以下地震的b值为0.8。 相似文献
120.
The method of wave-function expansion in elliptical coordinates,elliptical cosine half-range expansion and Mathieu function were applied to obtain an exact analytical solution of the dynamic stress concentration factor(DSCF)around an elliptical cavity in a shallow,semi-elliptical hill.An infinite system of simultaneous linear equations for solving this problem was established by substituting the wave expression obtained by the Mathieu function including the standing wave expression of elliptical lining given herein into the boundary condition obtained by the region-matching method.The finite equations system with unknown coefficients obtained by truncation were solved numerically,and the results in the case of an ellipse degenerating into a circle were compared with previous results to verify the accuracy of the method.The effects of different aspect ratios,incident wave angles and aperture ratios on the dynamic stress concentration around the elliptical cavity were described.Some numerical results,when the elliptical hill was changed into a circular one,were analyzed and compared in detail.In engineering,this model can be regarded as a semi-cylindrical hill with an elliptical cylindrical unlined tunnel under the action of SH waves,and the results are significant in aseismic design. 相似文献