当前我国地震预报面临的主要科学问题及其建议

论述了我国目前在长期、中期和短临预报中所面临的主要科学问题，提出了从哪些方面进行突破的建议。     

Nonlinear earthquake response analysis and energy calculation for seismic slit shear wall structures

Based on the concept of structural passive control, a new type of slit shear wall, with improved seismic performance when compared to an ordinary solid shear wall, was proposed by the authors in 1996. The idea has been verified by a series of pseudo-static and dynamic tests. In this paper a macro numerical model is developed for the wall element and the energy dissipation device. Then, nonlinear time history analysis is carried out for a 10-story slit shear wall model tested on a shaking table. Furthermore, the seismic input energy and the individual energy dissipated by the components are calculated by a method based on Newmark-β assumptions for this shear wall model, and the advantages of this shear wall are further demonstrated by the calculation results from the viewpoint of energy. Finally, according to the seismic damage criterion on the basis of plastic accumulative energy and maximum response, the optimal analysis is carried out to select design parameters for the energy dissipation device.     

Early Yanshanian post-orogenic granitoids in the Nanling region Petrological constraints and geodynamic settings

Early Yanshanian magmatic suites predominate absolutely in the Nanling granite belt. They consist mainly of monzogranite and K-feldspar granite. There occur associations of early Yanshanian A-type granitoids (176 Ma-178 Ma) and bimodal volcanic rocks (158 Ma-179 Ma) in southern Jiangxi and southwestern Fujian in the eastern sector of the granite belt and early Yanshanian basalts (177 Ma-178 Ma) in southern Hunan in the central sector of the belt. Both the acid end-member rhyolite in the bimodal volcanic rock association and A-type granitoids in southern Jiangxi have the geochemical characteristics of intraplate granitic rocks and the basic end-member basalt of the association is intraplate tholeiite, while the basaltic rocks in southern Hunan include not only intraplate tholeiite but also intraplate alkali basalt. Therefore the early Yanshanian magmatic suites in the Nanling region are undoubtedly typical post-orogenic rock associations. Post-orogenic suites mark the end of a post-collision or late orogenic event and the initiation of Pangaea break-up, indicating that a new orogenic Wilson cycle is about to start. Therefore it may be considered that the early Yanshanian geodynamic settings in the Nanling region should be related to post-orogenic continental break-up after the Indosinian orogeny and the break-up did not begin in the Cretaceous.     

岫岩-海城5.4级地震前小震震源机制解与记录特征分析

采用Pn、Pg初始波初动符号，利用乌尔夫网上半球投影，用作图方法求解了岫岩－海城震区（1999年1月－1999年11月29日）主震前辽宁数字地震台网记录（ML≥2.5)的41个小震的震源机制参数。结合前震记录的某些特征，对主震前应力方向的时空变化，震源错动性质进行分析和讨论。     

GPS导航技术在伊拉克战争中的应用

论述了GPS导航定位技术在伊拉克战争中的作用，着重分析了GPS在精确制导武器中的应用形式和效果，并预测了美国在GPS应用方面未来将要进行的努力。     

A Further Study on the Mechanism of Airdecking

Airdecking is used in mining for two quite different applications. One is to enhance the fragmentation by amplifying the induced fracturing and the second is for pre-split blasting in which the borehole fracturing is reduced. This paper deals with the first of these effects. A forth coming paper will describe pre-splitting by airdecking. The use of air decks to enhance rock fragmentation and so to reduce explosive costs has been the practice for quite long time. Although a number of studies has been conducted to verify the advantages of blasting with air decks and to investigate the mechanisms involved, the proposed mechanisms still cannot explain clearly the phenomena observed in practice and the design approach adopted for this kind of blasting is still primary based on rules-of-thumb. In this paper, the theory of shock tubes is adopted to (a) investigate the processes of the expanding detonation products, (b) study the interactions between the explosion products and the stemming or bottom of blasthole, and (c) to decide the distribution of the changing pressure of explosion products along blasthole. Numerical simulation and theoretical analyses are then performed to study the physical process of blasting with air decks. Finally, a reasonable value for the airdecking ratio is decided theoretically. It is shown that the pressure-unloading process caused by the propagation of the rarefaction wave and the reflected rarefaction waves in the detonation products plays an important role in the enhanced fragmentation of rock when blasting with air decks. The unloading process can induce tensile stresses of rather high magnitude in the rock mass surrounding blasthole. This favors fracturing of the rock. The reflected shock wave with a magnitude of gas pressure higher than that of the average detonation pressure in a fully charged blasthole acts as the main energy source to break the rock in the air deck and stemming portions. The second and succeeding strain waves induced by the unloading or reloading of the pressurewithin the blasthole also contribute to form the initial fracture network in the rock around the blasthole. It is also revealed that there exists a reasonable range of values for the airdecking ratio. For ANFO, this value varies from 0.13-0.40.     

1997年4月6日、11日、16日新疆伽师4次6.3～6.6级地震烈度分布及震害特征

1997年4月6日、11日、16日新疆伽师继1月21日和3月1日3次6级以上地震之后又连续发生了4次6级以上地震。极震区烈度达Ⅷ度．极震区内的英买里乡所有Ⅰ类房屋几乎全部倒塌或严重破坏；江巴孜乡、和夏阿瓦提乡、克孜勒苏乡和巴仁镇的大部分房屋倒塌或严重破坏。在地下水位高、土质松散地区出现大面积喷水冒砂与地裂缝。根据震害评估与宏观考察资料，介绍了各烈度区的震害特征。     

砷的仪器分析方法新进展

砷是自然界中广泛存在的一种物质在工业，农业，医药等方面应用很广。笔者着重介绍了近几个来砷的仪器分析方法新进展，主要有光度法，电化学法，原子吸收法等。     

辽宁水泉金矿综合信息找矿模型及预测

通过对辽宁水泉金矿的基础地质研究和综合找矿信息分析，并根据该矿区资源危机，缺乏后备金矿储备的实际情况建立了水泉金矿综合信息找矿模型。对远景成矿靶区进行了初步圈定，为详细地质勘查、扩大金矿资源提供了依据。     

金伯利岩中新发现的两种Zr-Ti、REE-Ti氧化物矿物──上地幔含大阳离子Cr、Ti、Fe氧化物矿物研究之四

在研究沂蒙矿、蒙山矿等地幔矿物时，新发现了两种Zr－Ti、REE－Ti氧化物矿物。Zr－Ti氧化物新相6个样品点的探针成分分析（wt％）：TIO227.756～46.811，ZrO231.724～58.092，TFeo2.75～5．82，CrO31．728～4．765，Nb2O51．353～4．357，Ta2O50．155～2.814，SiO20．894～13．749，主次元素的成分变化幅度均较大，但以氧为4计算的阳离子总数均为2，因此分子式可简写为（Ti，Zr，Si，Fe）2O4或（Ti，Zr）2O4，与人工化合物ZrTiO4相似。REE－Ti氧化物矿物新相的成分也较复杂，主要元素为REE（Ce，Nd，La，Sm，Pr…）及Ti，次要元素有Nb，根据五个样点的探针分析结果，简化的分子式（Ce…）2（Ti…）3O9，与人工化合物Ce2Ti3O8.7类似，属等轴晶系。两个新矿物相均产于蒙山矿中的微裂隙和熔融交代海绵边中，呈斑点状、蠕虫状、微脉状，组成元素复杂，不同颗粒分析点成分有差异，且在同一微脉中成分也有变化，反映了这两种新矿物相是非平衡的交代一结晶产物。从矿物的产出关系和成分的特征来看，它们的形成与地幔流体交代作用有关。