NaCl在DMF和1,2-丙二醇混合溶剂中电导的研究

在283~308K温度范围内测定了NaCl在DMF和1,2-丙二醇混合溶剂中的电导率,根据公式求得NaCl的摩尔电导率值,应用Kohlrausch经验规则,使用Origin软件进行线性拟合,作图外推求得NaCl在DMF和1,2-丙二醇混合溶剂中的无限稀释摩尔电导率λ0值,并讨论了NaCl溶液的电导率、摩尔电导率、无限稀释摩尔电导率与温度和浓度的关系。     

A series solution for surface motion ampli-fication due to underground group cavities: Incident P waves

Introduction In recent years some big cities in China commonly build subways in central urban areas to improve crowded surface transportation, and the subways usually are large-scale group cavities composed by two parallel cavities. Construction of large-scale group cavities will certainly affect the design ground motion near the cavities, and further affect seismic safety of the existing build-ings nearby. So it is of significance to estimate this effect on seismic design of the buildings. H…     

大同晚期强余震前震源机制解的一致性特征

取层状介质中一点源位错模型，由计算综合地震图得到P、S各自最大振幅，通过其最大振幅比值与观测资料拟合的方式来确定震源机制。大同遥测地震台网较好地记录了大同地震序列的大量小震。经系统地查阅台网和周围其他台站1990-2002年的全部记录，读取垂直向的P、S最大振幅数据，反演计算得到620个小地震的震源机制解。这些解的优势取向和华北构造应力场的方向相同。定义各个震源机制解的P、N、T轴和构造应力场的3个应力主轴在3维空间的夹角之和为一致性参数，发现在1991年和1999年发生的晚期强余震前2-8个月，一致性参数出现显著的下降。我们认为，这是具有短期预测意义的现象。     

正交加肋地基板在谐荷载作用下的动力响应

将加肋地基板作为板-梁耦合系统，考虑弹性地基模型，建立土—基础耦合系统的运动微分方程，通过富氏积分变换及其逆变换，演绎出双向正交加肋钢筋混凝土地基板在设备谐激力作用下的振动响应的半解析解法。结果说明，在土建设计中，为了减少振动对环境的有害影响，应考虑动力设备基础的隔振和减振问题。数值算例也表明，本方法有较好的计算精度。     

2003年伽师6.8级地震序列特征和震源机制的初步研究

在位于1997-1998年新疆伽师9次6级地震分布区域的东南端，2003年2月24日又发生6．8级地震。结合伽师6．8级地震序列震源机制解结果，对该地震序列的基本特征和震源区应力降等进行了对比分析。结果表明，6．8级地震断层是在北西向的区域应力场挤压作用下产生的倾滑逆断层，震源以单侧破裂为主，破裂方向与极震区走向，以及北西向的主压应力方向一致。震前震源区应力显著增强，震后应力释放较为彻底。中强余震震源机制解与主震有明显差异，表现出震源区应力场处于不稳定的调整阶段，余震震源机制的差异为震后地震趋势的判定提供了依据。     

Experimental evaluation of piecewise exact solution for predicting seismic responses of spherical sliding type isolated structures

The use of base isolation for enhancing seismic resistibility has been proven as an efficient method in experimental and theoretical studies. It is usual to insert a flexible device in the horizontal direction to permit the most of relative deformation of a structure at this level. Because the rigidity of the superstructure is much higher than that of the base isolator underneath the structure, the behavior of the superstructure can be idealized as a rigid body during earthquakes. In general, hundreds of degrees of freedom and a step‐by‐step time history analysis are the basic requirements for calculating the seismic response of a base‐isolated structure under earthquakes. In order to develop a simple tool which can be easily adopted for calculating the seismic responses of the spherical sliding type isolated structures, a piecewise exact solution for predicting the seismic responses of base‐isolated structures has been derived in this study. The comparison between the experimental results conducted at the National Center for Research on Earthquake Engineering (NCREE) in Taiwan and the analytical results obtained from the piecewise exact solution show that the formulation derived in this study can predict the seismic responses of the base‐isolated structure with a very high accuracy. Copyright © 2005 John Wiley & Sons, Ltd.     

GPS time-series and its response to M S=8.1 Kunlunshan earthquake

In this paper, observation data in 25 GPS reference stations of China have been analyzed by calculating GPS position coordinate time-series with GIPSY. Result shows there is an obvious trend variation in such time-series. The trend variations of time series along the longitude and latitude coordinate reflect the motion of each position in the global-plate, in which the trend variation in the vertical direction reveals some large-scale construction information or reflects the local movement around the positions. The analysis also shows that such time-series have a variation cycle of nearly 1.02 a, but the reason still remains to be further studied. At the end of this paper, response of the time-series of M _S=8.1 Kunlunshan earthquake was analyzed, and the seismogenic process of M _S=8.1 Kunlunshan earthquake, according to the time proceeding and the feature of anomaly, was divided into 3 phases—changes in blocks with forces, strain accumulation, quick accumulation and slow release of energy. At the initial stage of seismogenic process of M _S=8.1 earthquake and at the imminent earthquake, coseismic process as well as during the post earthquake recovery, anomaly in vertical direction is always in a majority. The anomalous movement in vertical direction at the initial stage resulted in a blocking between faults, while at the middle stage of seismogenic process, the differential movement between blocks are in a majority, which is the major reason causing energy accumulating at the blocking stage of faults. Foundation item: National Natural Science Foundation of China (40074024 and 40304002).     

~(40)Ar-~(39)Ar Age and Geological Significance of the Sawur Gold Belt in Northern Xinjiang, China

1 IntroductionThe Sawur gold belt is an eastward extending section ofthe Zarma-Sawur gold-copper belt in Kazakhstan, locatedin the Sawur Mountain, northern Xinjiang, and mainlycomprises two large- to medium-sized gold deposits,accompanied by five small gold deposits and a series ofgold ore spots (Yin et al., 1996, 2003; Wang et al., 1999; Liet al., 2000; Liu et al., 2003; Shen et al., 2004a). TheKuo'erzhenkuola and Bu'erkesidai gold deposits are thebiggest and most important ones in this …     

The structure of SrTiOGeO4 and its solid solution with CaTiOGeO4

Solid solubility and structural phase transitions in (Ca _x Sr_1-x )TiOGeO₄have been studied by means of in situ high temperature X-ray powder diffraction. The displacive A2/a–P2₁/a phase transition analogous to titanite has been followed across the solid solution. Strain analysis indicates a transition temperature of T _c=594 ± 10 K for SrTiOGeO₄ and the additional occurrence of an isosymmetric anomaly at T _i =800 ± 25 K, in analogy to the isomorphous compound CaTiOGeO₄. Lattice parameters as a function of temperature and composition have been determined by X-ray powder diffraction between room temperature and a maximum temperature of 1123 K. The e ₁₁ and e ₁₃ components dominate the strain tensor. All compositions across the solid solution exhibit close to tricritical phase transitions P2₁/a–A2/a. The critical temperature remains almost unaffected by substitution of Sr for Ca, but the magnitude of the spontaneous strain drops significantly with even small amounts of Sr present.