CHARGING OF DUST GRAINS IN COMETARY PLASMA ENVIRONMENTS

The equilibrium potential of fluffy dust grains in plasma environments is modeled numerically for comet P/Halley. It is found that the dust grain acquires its largest negative potential and probability of disruption at about 50, 000km from the comet where the mass spectrum measured by the spacecraft took a great change.     

大功率多源充电法在黄山铜镍矿区的应用

在新疆305项目专题研究中,根据大功率充电法提供的资料,于黄山铜镍矿区设计的3个异常验证孔,见铜镍矿总厚度303.43m。获铜镍科研预测储量约60万t。     

Spacecraft potential control aboard Equator-S as a test for Cluster-II

The payload of Equator-S was complemented by the potential control device (PCD) to stabilise the electric potential of the spacecraft with respect to the ambient plasma. Low potentials are essential for accurate measurements of the thermal plasma. The design of PCD is inherited from instruments for Geotail and Cluster and utilises liquid metal ion sources generating a beam of indium ions at several keV. The set-up of the instrument and its interaction with the plasma instruments on board is presented. When the instrument was switched on during commissioning, unexpectedly high ignition and operating voltages of some ion emitters were observed. An extensive investigation was initiated and the results, which lead to an improved design for Cluster-II, are summarised. The cause of the abnormal behaviour could be linked to surface contamination of some emitters, which will be monitored and cured by on-board procedures in future. The mission operations on Equator-S were not at all affected, because of the high redundancy built into the instrument so that a sufficient number of perfectly operating emitters were available and were turned on routinely throughout the mission. Observations of the effect of spacecraft potential control on the plasma remained limited to just one event on January 8, 1998, which is analysed in detail. It is concluded that the ion beam lead to the predicted improvement of the particle measurements even outside the low density regions of the magnetosphere where the effect of spacecraft potential control would have been much more pronounced, and that the similar instruments for the four Cluster-II spacecraft to be launched in 2000 will be very important to ensure accurate plasma data from this mission.     

多参数物探测量在探测岩溶裂隙上的应用

本文所述工程实例开始设计应用视电阻率测深来探测工程区的岩溶裂隙发育情况。实际工作中,根据电阻率测深时各种参数的变化来进行综合资料解释,发现在测深时随着测量极距的变化而电位差未变这一反常现象,从而判断在该极距范围内为一等势体,改用充电法圈定等势体范围,很好地探明了工程区的岩熔裂隙发育情况。     

电火花震源系统充电技术研究

电火花震源是海洋工程地震勘探作业中一种较好的震源,但"十五"之前我国的电火花震源主要依靠进口,仪器维护费用高、周期长。"十五"期间国家海洋局第一海洋研究所研制了海洋电火花系统PSS500J,并取得了很好的应用效果。结合PSS500J研究成果,介绍了电火花震源的构架,分析了电火花震源充电技术的两种设计方案,对震源工作中安全保障提出了技术建议。     

井中激电在西霞矿区的应用

以西霞矿区ZK001孔的井中激电为实例,介绍了井中激电在该矿区的应用效果及推断解释方法。说明井中激电在对地面激电异常验证中可以判断、验证钻孔是否已揭露异常体及异常体的空间展布状况。     

Gas charging history of the Yingcheng Formation igneous reservoir in the Xujiaweizi Rift, Songliao Basin, China

Systematic analysis of fluid inclusions was carried out on 34 samples from the Yingcheng Formation igneous reservoir of the Xujiaweizi rift, Songliao Basin, China. On the basis of petrographic characterization, the results of the microthermometric analyses indicated that the Yingcheng Formation igneous reservoir trapped six clusters of pure aqueous inclusions, and only four of them have the coeval gas-bearing aqueous inclusions been detected in the analyses. So the Yingcheng Formation igneous reservoir experienced four gas charging events during its evolutionary history. Combined with the research results of burial history and cap rocks, the four gas charging events happened during the time interval from 120 to 85 Ma, and every charging time is no more than 10 Ma. The main gas charging is the third, which happened during the time interval from 105 to 95 Ma.     

最优尺度回归在储层孔隙度主控因素分析中的应用

本文以实测物性、粒度分析及铸体薄片鉴定为基础,结合对东濮凹陷濮卫地区沙二-沙四段储层孔隙度影响因素的分析,利用最优尺度回归方法,定量分析了储层孔隙度的主控因素。研究表明,最优尺度回归可以简便快捷地定量分析多因素对孔隙度的重要程度。分析结果显示各类影响因素重要性排序为:含油级别、层位、胶结物含量、储层与膏盐岩位置关系、压实减孔率及分选系数。成岩作用早期,分选性决定了储层的初始孔隙,压实作用是孔隙度减小的最主要的原因;成岩作用中后期,烃类充注是储层孔隙度得以保存的最主要的原因。     

大功率激发极化法在内蒙古马戈山南多金属矿区找矿中的应用

内蒙古东乌珠穆沁旗地区处于我国北方的一条重要成矿带上,但是在深部找矿方面没有新的突破.文章主要是对马戈山南地区多金属勘查中大功率激发极化法的应用进行总结.通过激电测深、激电中梯剖面测量,找出测量异常区进行合理解释后,指导勘探工程设计、圈定找矿远景区.以期能对相关区域的多金属勘查有一定参考和指导意义.