箭竹生长及开花的气象条件研究

通过对我国历史上箭竹开花及王朗自然保护区箭竹生长气象条件的研究认为，箭竹开花多在冬暖夏凉的年份；箭竹的生长量可由气象因素的变化来进行预测。研究结果可为保护大熊猫提供一定的气象依据。     

Process and mechanism for oil and gas accumulation,adjustment and reconstruction in Puguang Gas Field,Northeast Sichuan Basin,China

With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Ch...     

华南基底变质岩的Sm-Nd同位素及其对花岗岩类物质来源的制约

华南地区存在两种类型变质基底。Sm-Nd同位素数据的研究结果表明,它们可分别代表华南两种类型元古代地壳端员。华夏地块区副变质岩代表成熟度较高的(早)元古代地壳端员,~(147)Sm/~(144)Nd=0.1198,~(143)Nd/~(144)Nd=0.511822;江南古岛弧区副变质岩代表成熟度较低的(中—晚)元古代地壳端员,~(147)Sm/~(144)Nd=0.1246,~(143)Nd/~(144)Nd=0.512170。根据上述数据得出了华南元古代地壳Sm-Nd同位素演化域,进而对华南不同时代花岗岩类的物质来源作了进一步的讨论。     

重庆玉峡锶矿床中分散元素锶的超常富集机制

重庆玉峡锶矿床位于华蓥山构造带的南段。含矿岩系为下三叠统嘉陵江组二段一亚段的含藻含膏白云岩,含矿层位自下而上有三个矿层。矿层呈似层状、透镜状赋存于西山背斜北段的背斜转折端及相邻两翼的层间虚脱部位。矿石矿物有天青石、菱锶矿、钡天青石,脉石矿物为白云石、...     

New records of Jurassic petrified wood in Jianchang of western Liaoning,China and their palaeoclimate implications

Diverse and rich fossil wood records have been documented from the Mesozoic of Liaoning Province, NE China. The Tiaojishan Formation(mainly distributed in Beipiao, Chaoyang, Fuxin and Jianchang regions) is one of the most significant horizons for the Jurassic petrified wood in Liaoning Province. Previously, wood fossils of this formation were mainly reported in Beipiao and Chaoyang regions, whereas fossil wood record was merely known in Jianchang region. Here we describe new fossil wood specimens from the Tiaojishan Formation in Jianchang County, western Liaoning. Two fossil wood taxa, i.e., Protaxodioxylon jianchangense Tian et Wang sp. nov. and Xenoxylon peidense Zheng et Zhang were recognized on the basis of anatomical features. These fossil wood records add new data for understanding the fossil wood diversity, floral composition and palaeoclimate of the Tiaojishan Formation. The occurrence of Xenoxylon and Protaxodioxylon implies a cool temperate, wet and seasonal climate condition with interannual variations during the Middle to Late Jurassic transition in western Liaoning region.     

量子化学从头计算法研究高岭石氢原子的位置

用量子化学从头计算法（ab initio）计算高岭石内层氢原子和外层氢原子的位置,计算出的内层氢原子平衡位置为：氢氧键与ab平面的夹角为-19.4°,氢氧键长0.098 28nm;外层氢原子平衡位置为：氢氧键与ab平面的夹角为64.4°,氢氧键长0.101nm。     

Silicon Isotope Geochemistry of Micro—Fine Disseminated Gold Deposits in SW Guizhou and NW Guangxi,China

Quartz was studied with respect to its silicon isotopic composition and cathodoluminescence in micro-fine disseminated gold deposits in SW Guizhou and NW Guangxi.The results showed that quartz in wall rocks.ores and that in association with hydrothermal silicification are distinctive in silicon isotopes and cathodoluminescence characters.Quartz in association with primary silicification is non-luminescent while that in wall rocks and associated with secondary silicification exhibits striking luminescence.Based on the dynamic fractionation of silicon isotopes,it is suggested that the mineralization was accompanied by rapid transport of aprimary siliceous fluid along the major deep fault system into subordinate faults before ore components deposited in favorable strata via penetration and metasomatism.Therefore,a deep origin is implicit for gold deposits of this type.     

中国科学院地理研究工作方向和任务的初步设想(在1965年中国科学院地理工作会议上的报告)

竺可桢同志1965年在中国科学院地理工作会议上所作的报告,全面分析了我国地理工作的现状和任务,阐明了分工和实现这些任务的措施。竺可桢同志的报告虽然已经过去了近二十年,但现在看起来,仍然有很大的指导意义,本刊特予以刊登,供大家学习参考。虽然报告中有些提法是针对当时情况的,地理研究机构和名称也有调整和变动,但为了保持这个历史性文件的完整,本刊未加更动。     

基于位移强度概念分析大坝变形规律

为改变以单个监测点为研究对象分析大坝变形规律的方法,提出位移强度概念,并以此作为分类标准,借鉴决策树算法,根据大坝所有监测点的坐标建立模型,计算并分析大坝在某一方向上的整体变形规律。