云南大丫口祖母绿颜色环带成因对多阶段成矿的指示意义

云南大丫口祖母绿常出现颜色环带,且伴随明显成分变化,而目前颜色环带的成因仍存争议,相关的多阶段成矿假说尚缺少明确证据。文章通过电子探针和激光剥蚀电感耦合等离子质谱仪对大丫口祖母绿的颜色环带及黑色矿物包裹体进行主微量元素成分分析,并对不同类型岩脉祖母绿中流体包裹体进行显微测温分析,进而探讨祖母绿颜色环带成因与多阶段成矿的联系。成分测试结果表明,从浅绿白核部至绿色边部,V(970×10^-6→10 077×10^-6)、Rb(9.6×10^-6→27.4×10^-6)、Cs(535×10^-6→3 108×10^-6)、Fe(1 376×10^-6→2 199×10^-6)和Ga(4×10^-6→14.7×10^-6)等微量元素的含量急剧增加。结合绿色晶体边部中同生黑色富钒电气石包裹体的分布,有力证明了大丫口祖母绿颜色分带的形成与晶体的多阶段成矿有关。流体包裹体测试结果表明,含矿长石-方解石脉、含矿石英脉和伟晶岩-变粒岩接触带中矿物的流体包裹体盐度范围分别为3.39%~10.36%(NaCl_eq)、5.71%~12.29%(NaCl_eq)和8%~18.72%(NaCl_eq),指示了伟晶岩脉中祖母绿的多阶段结晶,且表明随结晶阶段演变,成矿流体的盐度逐渐升高。同时,成矿流体盐度升高也是晚期云英岩化阶段致色元素含量剧增的原因。     

青藏高原近地面层特征的初步分析

利用西藏日喀则、那曲１９９３年７月至１９９４年４月近地面层梯度观测资料，采用近地面层相似理论方法，计算了观测期间地面粗糙度、平均曳力系数、平均动量通量、平均感热通量和平均湍流系数，讨论了它们与稳定度的关系，给出了日变化个例。     

直接/间接作用模式下一株短小芽孢杆菌对蒙脱石层间域特性的影响研究

为探讨直接/间接作用模式下土壤常驻菌对蒙脱石层间距、层电荷及层间介质的影响,从绵阳地区紫色土壤中分离选取1株短小芽孢杆菌,利用透析袋,建立土壤菌与蒙脱石"接触"与"非接触"体系进行相互作用实验。作用5 d后的结果表明,蒙脱石样品层间距变小,样品M-1和M-2的d001值从1.486 nm分别减小到1.246 nm和1.257 nm,单位半晶胞层电荷数减少,且ξMMTξM-2ξM-1,FTIR分析显示作用后蒙脱石样品出现来自蛋白质酰胺Ⅱ带及蛋白质分子甲基的新特征峰,层间水分子3434 cm-1、1637 cm-1处的峰发生偏移,此外阳离子交换容量也发生明显改变。土壤菌的生物作用能改变蒙脱石的层间距、层电荷及层间介质,使其结构和性质发生改变。对比2种作用方式与作用后蒙脱石层间域特性的改变分析可知,接触作用对蒙脱石层间域特性的改变效果强于非接触作用。     

《中日亚洲季风机制合作研究计划》青藏高原观测研究概况

详细介绍了自１９９３年开始以来《中日亚洲季风机制合作研究计划》在青藏高原上观测研究的一些基本情况。包括三个部分：观测仪器的特点、观测环境的气候特征和观测项目（要素）；观测资料的特点；部分观测资料的初步分析结果介绍     

陕甘宁地区植被恢复对气候变化和人类活动的响应(英文)

The "Grain for Green Project" initiated by the governments since 1999 were the dominant contributors to the vegetation restoration in the agro-pastoral transitional zone of northern China. Climate change and human activities are responsible for the improvement and degradation to a certain degree. In order to monitor the vegetation variations and clarify the causes of rehabilitation in the Shaanxi-Gansu-Ningxia Region, this paper, based on the MODIS-NDVI and climate data during the period of 2000-2009, analyzes the main charac-teristics, spatial-temporal distribution and reasons of vegetation restoration, using methods of linear regression, the Hurst Exponent, standard deviation and other methods. Results are shown as follows. (1) From 2000 to 2009, the NDVI of the study area was improved progres-sively, with a linear tendency being 0.032/10a, faster than the growth of the Three-North Shelter Forest Program (0.007/10a) from 1982 to 2006. (2) The vegetation restoration is characterized by two fast-growing periods, with an "S-shaped" increasing curve. (3) The largest proportion of the contribution to vegetation restoration was observed in the slightly improved area, followed by the moderate and the significantly improved area; the degraded area is distributed sporadically over southern part of Ningxia Hui Autonomous Region as well as eastern Dingbian of Shaanxi province, Huanxian and Zhengyuan of Gansu province. (4) Climate change and human activities are two driving forces in vegetation restoration; more-over anthropogenic factors such as "Grain for Green Project" were the main causes leading to an increasing trend of NDVI on local scale. However, its influencing mechanism remains to be further investigated. (5) The Hurst Exponent of NDVI time series shows that the vegetation restoration was sustainable. It is expected that improvement in vegetation cover will expand to the most parts of the region.     

平差值函数的权倒数与推算路线无关

在三角网的条件平差中，往往还要评定网中最弱边的精度，即求出最弱边的相对中误差。三角网中最弱边可从不同的已知边求得，也可由同一已知边起算，经过不同的推算路线求得。这就产生一个问题：沿不同推算路线求出同一最弱边的权倒数是否相同？本文就这类问题予以探讨。     

气候变化背景下钙华退化影响因素及其保育措施研究进展

为厘清黄龙钙华退化受气候变化调控规律,探究影响钙华沉积的生物与非生物因素对气候变化产生的响应,通过对钙华相关研究的专著及文献进行分析,从直接影响气候变化的水文因素和大气二氧化碳浓度出发,探索其对钙华退化的影响,表明水文过程及气候变化引起的极端事件是导致钙华退化的主要原因:(1)适宜的气候加速钙华沉积,极端的气候则会引起...     

川滇菱块MS≥6.0地震时空对称特征及趋势判断

正文章编号院1001-8662渊2020冤01-0011-10     

顾及偏态的IQR法则在GPS时间序列异常值探测中的应用

引入非正态数据分布偏态因子MC值对GPS时间序列的偏态性进行度量,并构造相应的函数,改进标准IQR法则中异常值的探测区间。利用Sopac提供的CHAN站时间序列进行实验,剔除异常值后进行插补,人工添加不同量级、不同密度的异常值。分别对比两种方案的探测结果,证实顾及偏态的IQR法则较标准IQR法则算法更严谨、探测效果更好。     

亟待解开楼兰古国消失的世纪之谜

漫漫黄沙所湮没滔滔水涸所造成屡屡战事所损毁楼兰,西域古国名。楼兰是中国西部的一个古代小国,国都楼兰城。西南通且末、精绝、拘弥、于阗,北通车师,西北通焉耆,东通敦煌,扼丝绸之路的要冲。历史上,楼兰是西汉时西域三十六国之一。张骞