Study of the characteristics of earthquake precursory anomalies of He and H2 Beijing No. 2 Cotton Mill well and their relation with earthquakes

This paper systematically summarized the relation of the abnormal change of He and H₂ dissolved gasses in deep hot-water well at Beijing No. 2 Cotton Mill and their relation with seismicity of the region. An empirical formula for the relation of the precursory anomaly of He and H₂ gasses with the magnitude and occurrence time of earthquake has been derived. Two events of magnitude greater than 5 in North China had been successfully predicted by using this formula. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 490–497, 1993.     

平行走滑断层相互作用的粘弹模型和减震作用

研究了二维粘弹性介质中平行走滑断层的相互力学作用及其地震活动性的影响。当一条断层发生滑动,将导致平行断层面上剪切应力减小,因此,可能推迟平行断层发生滑动,推迟时间在几年至几百年的范围内,这取决于发生滑动的断层与平行断层之间的距离,以及平行断层自身应力积累孕育地震过程经历的时间。     

云南水汞在连发地震前短临异常及震后变化特征

通过对1995年5月6日—1996年2月3日发生在云南境内及其中缅边境一带的4组5次M≥6．0级强震的研究,发现水汞在强震连发期都出现短临异常及震后变化;与2001年云南省内6组7次5．0—5．9级中强地震短临异常及震后变化进行比较,结果表明强震连发期水汞的短临异常特征表现为异常台站多、异常幅度大、异常范围广和多台站水汞在异常中发震。中强震连发期水汞的短临异常特征与此相反。表现为异常台站少、异常幅度小、异常范围小和多台站水汞在异常结束后发震。     

山西义兴寨金矿床金矿物颗粒的产出及其成矿动力学意义

山西义兴寨金矿床的金主要呈包体金和裂隙金两种产出状态.文章根据成矿地球化学动力学理论,论证了金元素在含矿断裂发生脆性破裂和脆-韧性扩张活动中析出的化学反应类型,以及受反应动力学条件的制约,形成矿石中金不同产出状态的规律.指出热液矿床中普遍存在的包体金为热液成矿早期阶段断裂发生脆性破裂和成矿流体沸腾,导致快速反应结晶的产物;而裂隙金和晶隙金为成矿晚期金等矿质在流体中残余富集,同时成矿断裂再次发生脉动破裂,即成矿热力学演化与有利的构造动力学因素耦合作用的结果.得出金矿物颗粒的产出状态具有成矿动力学意义的结论.     

内蒙撰山子金矿赋存规律及成矿预测

内蒙赤峰南部众多金矿床（点）多集中在槽区的地台一侧,而撰山子是赤峰地区产于槽区的唯一成型的金矿床。撰山子金矿赋存规律的研究,不但对该矿生产有指导意义,而且对该区槽区找矿工作也有十分重要意义。在研究金矿赋存规律的基础上,指出了找矿远景区。     

Distribution and fractionation mechanism of stable carbon isotope of coalbed methane

The stable carbon isotope values of coalbed methane range widely, and also are gener- ally lighter than that of gases in normal coal-formed gas fields with similar coal rank. There exists strong carbon isotope fractionation in coalbed methane and it makes the carbon isotope value lighter. The correlation between the carbon isotope value and Ro in coalbed methane is less obvious. The coaly source rock maturity cannot be judged by coalbed methane carbon isotope value. The carbon isotopes of coalbed methane become lighter in much different degree due to the hydrodynamics. The stronger the hydrodynamics is, the lighter the CBM carbon isotopic value becomes. Many previous investigations indicated that the desorption-diffusion effects make the carbon isotope value of coalbed methane lighter. However, the explanation has encountered many problems. The authors of this arti- cle suggest that the flowing groundwater dissolution to free methane in coal seams and the free methane exchange with absorbed one is the carbon isotope fractionation mechanism in coalbed methane. The flowing groundwater in coal can easily take more 13CH4 away from free gas and com- paratively leave more 12CH4. This will make 12CH4 density in free gas comparatively higher than that in absorbed gas. The remaining 12CH4 in free gas then exchanges with the adsorbed methane in coal matrix. Some absorbed 13CH4 can be replaced and become free gas. Some free 12CH4 can be ab- sorbed again into coal matrix and become absorbed gas. Part of the newly replaced 13CH4 in free gas will also be taken away by water, leaving preferentially more 12CH4. The remaining 12CH4 in free gas will exchange again with adsorbed methane in the coal matrix. These processes occur all the time. Through accumulative effect, the 12CH4 will be greatly concentrated in coal. Thus, the stable carbon isotope of coalbed methane becomes dramatically lighter. Through simulation experiment on wa- ter-dissolved methane, it had been proved that the flowing water could fractionate the carbon isotope of methane, and easily take heavy carbon isotope away through dissolution.     

棉铃虫种群消长及影响因子

耕作制度的改变,为棉铃虫种群数量上升提供了良好的食物源和生态环境;大面积使用化学农药,不仅削弱了天敌的控害作用,也提高了棉铃虫的抗药性;气候变暖,适宜于棉铃虫数量上升。因此,棉铃虫种群增加,棉花、玉米、小麦、豆类、瓜菜等受害也明显加重。要控制棉铃虫的发生程度,首先要防治棉田外一代幼虫和卵,减少一代种群数量;对二代棉铃虫,宜有选择地使用化学农药和生物农药进行防治,并充分发挥天敌的自然控制力,以减少种群数量;三代、四代棉铃虫主要危害作物繁殖器官,直接影响作物的产量和品质,以物理诱杀和玉米诱集带集中诱杀为主,既可控制其危害,又对其天敌无负面影响;五代棉铃虫虽对当年作物产量影响不大,但其种群数量直接影响下一年一代发生量,因此应及时喷施病毒类等生物性药剂,降低其越冬种群,同时也保护自然天敌安全越冬。     

藏北赤布张错南部帮麦锑金矿点的地质特征及意义

在1:25万赤布张错幅区域地质调查中发现了帮麦锑金矿点,本矿点属于美多-尕尔巴阔尔锑、汞、砷成矿带.介绍了帮麦锑金矿点的地质概况和矿化特征,并与该矿带中规模最大、最典型的美多矿床作了比较,认为帮麦锑金矿点在矿种类型和时空分布上有别于美多-尕尔巴阔尔锑、汞、砷成矿带上其他已知的矿床或矿点,说明该矿带向北西延伸部分表现出了新的特点:矿体主要赋存于北西向断裂带内,金的含量增加,矿体与硅质岩关系不大,在成矿时间上可能早于美多等赋存于北东向断裂中的矿床.     

中国煤层气勘探开发进展综述

综述了中国煤层气勘探开发利用现状,尤其是"十五"期间中国煤层气取得的进展.总结了中国煤层气资源勘探开发成果:基础研究和应用研究齐头并进;勘探方向更加明确;煤层气勘探开发关键技术类型多样,试验推广应用范围扩大;十大重要勘探成果初露煤层气产业化曙光.国家级沁南潘河煤层气开发示范项目、晋城寺河煤层气开发项目、沁南枣园煤层气开发试验项目、阜新煤层气开发试验项目的建成和投产,标志着中国开始进入煤层气商业化开发阶段.     

定向羽状水平井在晋南沁水盆地煤层气开发应用中存在的问题

定向羽状水平井是指通过定向井、多分支水平井技术,由地面垂直向下钻至造斜点后以中、小曲率半径侧斜钻进目的煤层主水平井,再从主井两侧不同位置水平侧钻分支井,进而形成像羽毛状的多分支水平井.这一技术是一项复杂的系统工程,目前在中国煤层气领域还处在研究和试验阶段,尚未形成一系列成熟的工艺与技术.