ENVIRONMENTAL SUSTAINABILITY AND SCENARIOS OF URBANIZATION IN ARID AREA——A Case Study in Wuwei City of Gansu Province

1IN T R O D U C T IO N The western China isfacinggrowing problems of eco- logicaland economic development. The disparitiebse- tween the socio-economy of the western and eastern China were enlarging, and the major ecologicalprob- lems stilelvolve as past(H…     

黄金的成色

黄金的成色并不是一成不变的，它成色的高低是与成矿温度、成矿阶段、深度、时代、变质程度、水溶液及风化作用等有一定关系，我们从这些关系中可以寻找到我们找矿的捷径和依据。     

Evidence for interacting loop process in a phase of the May 16, 1981 flare

The behaviour of the flare in the period of enhancement and maximum of hard X-ray, microwave and decimetric type IV continuum is analysed. The elongation of the H ribbons and microwave source disclose that the energy release site was shifting through a system of loops with a velocity less than 200 km s^-1, and that the energy was carried down the field lines with a velocity of about 1000 km s^-1, implying the thermal conduction front mechanism of energy transport. Several processes of energy release are considered and it is concluded that an explanation in terms of succeeding interactions of neighbouring loops, involving fast reconnection of their poloidal components is in best agreement with the observations.Proceedings of the Second CESRA Workshop on Particle Acceleration and Trapping in Solar Flares, held at Aubigny-sur-Nère (France), 23–26 June, 1986.     

Emission features in the solar corona after the perihelion passage of Comet 1979 XI

On the coronograph spectrophotographic records taken on 31.372 UT, August 1979, some faint emission features were found which can be ascribed to Siii and Niii. These emissions were obviously a transient phenomena which were detected only 10 hr after the supposed fall of Comet 1979 XI in the Sun's photosphere. It cannot be excluded that the appearance of Si and Ni lines was triggered by the evaporation of dust particles with a high abundance of heavier elements in the solar corona. This assumption is also supported by intensity distribution of the Fex coronal line around the Sun's limb. The maximum coincide with the position angle of the projected path of the comet.     

内蒙古敖包吐萤石矿床的Sr、Nd、Pb同位素地球化学特征

敖包吐萤石矿床是内蒙古北部苏莫查干地区单一萤石矿集区中的一个代表性矿床,产于早二叠世大石寨组火山-沉积岩与早白垩世敖包吐花岗岩的接触带上。文章通过分析该矿床岩、矿石的微量元素和稀土元素,揭示出萤石的成矿作用可分为2个阶段,即交代作用和充填作用。交代作用过程中大石寨组的结晶灰岩可能为萤石的形成提供了部分Ca来源,萤石矿石的稀土元素配分模式与海水基本类似,具有Ce负异常;成矿作用后期主要表现为充填作用,形成颗粒粗大的萤石,表现为重稀土元素富集的特征,并随着萤石的沉淀析出,稀土元素总量逐渐下降,反映出成矿流体经历了较长期的演化过程。各地层单元、花岗岩体和萤石矿石的Sr、Nd、Pb同位素研究表明,萤石的放射性同位素组成具有壳、幔源混合的特点,成矿物质来源具有多源性。早白垩世敖包吐花岗岩可能是萤石中F的主要来源,而大石寨组的结晶灰岩则可能提供了Ca。另外,Pb、Nd同位素的极大不均一性,有可能是成矿流体在运移过程中对艾力格庙群放射性组分的选择性吸收的结果。萤石成矿作用与钾玄岩的时空关系暗示了萤石的成矿过程可能是中国东部岩石圈减薄和下地壳的置换地质事件的结果。在构造转型的过程中,燕山中期富碱的酸性花岗岩浆的活动分异出富含F的成矿流体,与幔源流体混合,沿区域重新活化的深大断裂和大石寨组的层间破碎带上升,交代其间的灰岩透镜体,从而形成敖包吐中型萤石矿床。     

相山铀矿田成矿物质来源探讨

铀源分析是铀矿床成因研究中的关键问题.在分析区域铀丰度特征的基础上,根据区域成矿物质在地质历史过程中的时空演化,结合相山矿田矿石铅同位素组成及岩、矿石微量元素地球化学对矿田铀源分析的指示,认为下寒武统地层为区域铀源层,相山火山盆地是区域成矿物质的"汇"区,岩浆及期后热液是铀的载体,即岩浆作用实现了铀从"源"到"汇"之间的物质转移.在岩浆演化过程中,铀向气液转移,为铀成矿提供了物质基础,岩浆期后流体-岩石相互作用,也促使了基底片岩、流纹英安岩中的部分铀进入成矿溶液.     

海带育苗水系微生物的监测与控制

现场及实验室试验表明,近岸水中细菌丰度因时因地有较大差别,近岸水在潮周期中以高潮前后细菌量较低;海水在沉淀贮存过程中细菌丰度有明显变化,且与海水中营养物含量、贮存温度等有关;海水经沙滤后能减少细菌90％左右;回水中脱落苗进入贮水池,是贮水池中细菌数量增长10余倍的主要原因。     

气溶胶的光学厚度与反射率比的处理方法

气溶胶光学厚度与气溶胶反射率比都是大气校正所需的重要大气参数，同时也是海洋水色卫星主要的数据产品，它们的测量精度将直接到卫星数据产品正演的精度和卫星数据产品的应用。文章在简述气溶胶光学厚度与气溶胶反射率比的基本测量原理和处理方法的基础上，结合多次试验数据结果进行简要的评价。     

普里兹湾陆缘水边界的变化

利用１９９８年１１月－１９９９年２月中国第１５次南极考察资料,讨论了普里兹湾附近陆缘水边界（ＣＷＢ）两侧的水团分布,以及ＣＷＢ的中心位置、锋面宽度、锋面强度、锋面的垂直深度和垂直厚度等物理特征的空间变化。并与１９９２年１２月－１９９３年２月中国第９次南极考察资料进行了比较,说明了ＣＷＢ的时间２变化。同时,还进一步分析了ＣＷＢ两侧海水运动的各向异性,以及动力高度场的形势,指出了动力高度槽,ＣＷＢ锋面     

Several significant hydrographic characteristics and their formation mechanism in the South China Sea during the spring and summer of 1998

INTRODUCTIONTheSCSisthelargestmarginseainthewestoftheNorthPacificOcean .Theprevailingwindinwinterisnortheast,whileinsummeritissouthwest .Itisstilluncertainthathowthecirculationandtemperature -salinityfieldassociatewiththemonsoonforcingandaccompanywithseveralkindsofvariationsbeforeorafterthesummermonsoonburst .DuringSECMEXin 1 998,twointensiveobservationperiods (IOP)havebeencarriedoutntheSCS (Fig 1 ) :IOP1 ,from 1 0Aprilto 5May ;IOP2 ,from 1 2JunetoJuly 6 ,inordertounderstandthe…