洞体形变在丽江7级大震前作了正确的中短期预报

洞体形变在丽江７级大震前作了正确的中短期预报陈德福１）何世海２）李旭东１）（１）国家地震局地震研究所，武汉４３００７１２）国家地震局分析预报中心，北京１０００３６）我国的应变型（不跨断层）洞体形变观测，包括地倾斜、重力、应变以及水位固体潮汐等项目，使...     

回顾冶金地质钻探的发展和今后的展望

回顾了冶金地质钻探的发展历程，划分为４个阶段，对前３个阶段的主要技术进步作了概括性的论述。并对今后的发展提出了几点看法。     

Ellerman Bombs,Type Ⅱ White—light Flares and Magnetic Reconnection in the Solar Lower Atmosphere

Ellerman bombs and type Ⅱ white-light flares share many common features despite the large energy gap between them.Both are considered to result from local heation in the solar lower atmosphere.This paper presents numerical simulations of magnetic reconnection occurring in such a deep atmosphere,with the aim to account for the common features of the two phenomena.Our numerical results manifest the following two typical characteristics of the assumed reconnection process:(1)magnetic reconnection saturates in-600-900s,which is just the lifetime of the two phenomens;(2)ionization in the upper chromosphere consumes quite a large part of the energy released through reconnection,making the heation effect most significant in the lower chromosphere.The applicationof the reconnection model to the two phenomena is discussed in detail.     

THE EFFECT OF DRAINAGE ON CHEMICALELEMENTS CONTENT OF MARSH

I INTRODUCTIONWetland has very important effect on retainingwater and against drought, regUlating climate, controlling soil erosion and so on ac. Today men often attachimportance to economic effect of wetland reclamation,but neglect and destroy other functions and effectswhich result in blind wetland development, a lot ofwetland degeneration. The area of freshwater wetland inthe 1950s was 134 x 10'ha, but in the 1970s 70% hadchanged into farmland (MITSCH, 1993). The area ofwetland in d…     

作为决策支持工具的地理信息系统的演变

地理信息系统(GIS)界是由多种人组成的集体。林学家、地理学者、地方政府机关、公共服务部门和科学研究工作者都在探讨这同一领域,但方向有所不同。联系的纽带是他们都涉及到空间参照数据,即地球表面上具体地区的属性。     

K-H Instability of Dust Plasma

Areview about K-H instability related to comet tail is presented.The effect of dust graing on KHI is theoretically analysed and relations of critical shear to excit KHI with the properties of dust grains both for sheared ion flow and for sheared dust flow re put out.Their possible application in comet tail is suggested.     

甲午海战后的清朝海军

清海军自甲午战败后,恢复十分缓慢。宣统元年(1909年),清政府为维护其风雨飘摇的统治,着手加强陆海军力量,决定第一年拨给海军开办经费700万两,以后每年拨绘经费500万两。同时,决定设立筹办海军事务处,任命郡王衔贝勒载洵和提督萨镇冰为筹办海军大臣,负责海军的整建工作。载洵是清代第一位海军大臣醇亲王奕谭的第6个儿子,光绪皇帝的弟弟。光绪死后,载洵另一个哥哥载沣