氦独来独往,在地球上,它的主要存在形式是单独离散的氦原子,即氦气;氦轻盈飘逸,它的密度很小,是除了氢气以外密度最小的物质;氦与世无争,几乎不与任何元素发生化学反应. 氦还是人类在地球以外发现的首个化学元素,人们通过对太阳光进行光谱分析发现了它.氦的名字取自希腊神话中的太阳神——赫里阿斯,也是为了纪念它与众不同的发现地——太阳.

冰:一种美丽的矿物标本 冬季,冰由大气中的水蒸气凝结成雪花、霜、冰雹,甚至是一定高度的永久积雪.在广袤的高纬度或高海拔地区,冰是池塘、湖泊、河流的覆盖层.特别是在南北两极和珠穆朗玛峰上,冰存在于冰川、永久冻结带(永久冰冻的下层土壤)和冰山中,部分形成冰盖(覆盖5万平方千米以上陆地的连续冰川冰)下的永久冰.当冰川到达海洋时,由洋流带入低纬度.地区,形成冰山.这些是自然冰的各种存在形式.

从地下流体观测井-含水层系统对降水的响应特征、对气压和潮汐的响应特征、含水层水文参数的计算对比以及水-岩作用平衡状态4个方面,研究了云南红河地区5 口地下流体观测井-含水层系统特征.结果表明:不同井-含水层系统对外界扰动(影响因素)的响应能力有所差别,其中高大井对地壳应变响应的灵敏性最强,其次是开远井、建水井,石屏井和蒙自井最弱,响应能力主要与井-含水层水力参数、承压性和水-岩平衡状态等因素有关.

The North China Plain (NCP) has the greatest area of severe land subsidence, accounting for more than 80% of the total area of severe land subsidence in China. The situation of prevention and control of land subsidence is urgent. Targeted researches are needed to carry out to provide scientific basis for effective prevention and control of land subsidence. A relatively complete land subsidence monitoring network is established in the NCP, and the current status and evolution of land subsidence are basically grasped. However, due to the limitation of the complex influencing factors and large variation in time and space of aquifer systems, the researches on groundwater-derived deformation characteristics and mechanism of soil layers are relatively weak so far, restricting the scientific evaluation of the development trend of land subsidence and its forecast and early warning. Based on summarizing the research progress of land subsidence at home and abroad, and analysing the current situation and development trend of land subsidence in the NCP with monitoring data of high temporal and spatial resolutions, the research directions of land subsidence under the influence of groundwater level changes are proposed. The land subsidence in the NCP was alleviated, and was effectively controlled in the downtown areas of the major cities such as Tianjin, Cangzhou and Hengshui. However, on the whole, the land subsidence in the NCP, especially in the Hebei Plain, is still in a relatively rapid development stage, because the exploitation of groundwater in the agricultural irrigation areas cannot be effectively controlled. Future researches on land subsidence in the NCP should focus on the land subsidence mechanisms and prediction and early warning, the law of soil deformation driven by groundwater level rise and its impact on the environment, the attributes of groundwater resources in the subsidence areas, and the relationship between geothermal development and land subsidence.

为探明诱发唐山矿冲击地压的主要因素,采用层次分析法构建了包含3个层级的计算矩阵,其中最顶层为主控性指标层,中间层包括地质力学因素、回采工艺过程和巷道支护3个方面,最低层包含埋藏深度、地质构造等14个影响因素,根据计算结果对这些因素进行影响程度排序.研究结果表明:影响唐山矿冲击地压发生的主要因素有水平应力、地质构造、工作面布置、推进速度,这4个指标的权值和为0.619,符合冲击地压主控性指标要求.

依据生活的水环境不同,鱼类可分为淡水鱼、咸水鱼以及部分有洄游习性的鱼.一般来说,陆地上的河流湖泊是淡水环境,盐度小于0.05％;海洋是咸水环境,盐度大于1.6％;盐度在这二者之间的过渡水域被称为半咸水环境.此外,也有部分干旱地区或高原地区的湖泊由于长年的蒸发量大于淡水补充量,其水域也形成了咸水环境,如青海湖.还有部分海域由于有大量的淡水河流或者冰川水补给,水体盐度远小于1.6％,从而形成了淡水海的环境,如波罗的海.那么,鱼是如何适应不同盐度的水体环境生存的?

康定地热田位于四川盆地西缘山地和青藏高原的过渡地带,属于高热流背景上的深循环高温地热系统。本文以康定地热田地下热水为研究对象,通过采集地热田内的主要两个热显示区（榆林河和雅拉河地区）的温泉和地热井的地下热水样,进行水化学和稳定同位素测试分析,研究其地下热水的补给来源和热储温度。雅拉河地下热水的水化学类型主要为HCO 3 -Na型水,榆林河地下热水的水化学类型主要为HCO 3 ·Cl-Na型水,均显示了深部地下热水沿断裂上涌与浅部冷水混合的特点。根据地下热水同位素的结果分析计算,康定地热田地下热水的起源均来自大气降水,雅拉河地下热水的补给高程为5 600~5 900 m,榆林河地下热水的补给高程为5 300~6 300 m,来源于南部的贡嘎山的可能性较大。榆林河地下热水具有明显的氧-18漂移现象,其原因为较高的热储温度,二氧化硅温标和阳离子温标的结果证明了这个判断,雅拉河地下热水的热储温度为172~188℃,榆林河地下热水的热储温度为192~288℃。

The Ordovician limestone aquifer of the Yanzhou coalfield in southwest Shandong Province is the main source of mine filling water and one of the main water supply sources,and hence the chemical characteristics and formation mechanism of the Ordovician limestone water can provide the basis for groundwater resource utilization and deep coal mining risk assessment.After sampling and analyzing of the groundwater,the authors found that the major chemical type of groundwater is SO4-Ca-Mg type.The SO42-values are from 537 mg/L to 2 296 mg/L,and the average concentrations of Ca2+ and Mg2+ are 455.7 mg/L and 116.6 mg/L respectively.The pH values range from 6.9 to 8.0.The TDS (total dissolved solids) values vary from 961 mg/L to 3 555 mg/L,increasing linearly with the increase of concentrations of Ca2+ and SO42-.These data indicate that the increase of TDS mainly comes from Ca2+ and SO42-.The saturation index (SI) data show that groundwater is oversaturated with dolomite and calcite,and undersaturated (SI＜0) with gypsum for most of the samples.In addition,the saturation index of gypsum is positively correlated with TDS of groundwater.These results suggest that the interaction between water and rock occurs during the transition of groundwater in limestone aquifer,mainly including dissolution of gypsum,precipitation or dissolution of dolomite and calcite,and ion exchange.

Major-ion compositions of groundwater are employed in this study of the water-rock interactions and hydrogeochemical evolution within a carbonate aquifer system. The groundwater samples were collected from boreholes or underground tunnels in the Ordovician limestone of Yanzhou Coalfield where catastrophic groundwater inflows can be hazardous to mining and impact use of the groundwater as a water supply. The concentration of total dissolved solid (TDS) ranged from 961 to 3555mg/l and indicates moderately to highly mineralized water. The main water-type of the middle Ordovician limestone groundwater is Ca-Mg-SO4, with SO42- ranging from 537 to 2297mg/l, and average values of Ca2+ and Mg2+ of 455.7 and 116.6mg/l, respectively. The water samples were supersaturated with respect to calcite and dolomite and undersaturated or saturated with respect to gypsum. Along the general flow direction, deduced from increases of TDS and Cl-, the main water-rock interactions that caused hydrogeochemical evolution of the groundwater within the aquifer were the dissolution of gypsum, the precipitation of calcite, the dissolution or precipitation of dolomite, and ion exchange. Ion exchange is the major cause for the lower mole concentration of Ca2+ than that of SO42-. The groundwater level of Ordovician aquifer is much higher than that of C-P coal-bearing aquifers, so the potential flow direction is upward, and the pyrite in coal is not a possible source of sulfate; additional data on the stable sulfur and oxygen isotopic composition of the sulfate may be helpful to identify its origin. Although ion exchange probably accounts for the higher mole concentration of Na+ than that of Cl-, the dissolution of aluminosilicate cannot be ruled out. The data evaluation methods and results of this study could be useful in other areas to understand flow paths in aquifers and to provide information needed to identify the origin of groundwater. Copyright (c) 2012 John Wiley & Sons, Ltd.