乌鲁木齐河山区冰雪水资源及径流量丰枯频率

乌鲁木齐河山区冰和雪资源，对径流补给，其量不很大，但对河水稳定起着很大作用和影响，冰川近几十年来一直退缩，冰川厚度冰薄，但冰川和融雪对乌鲁木齐河径流一直起着调剂和“保证”作用，山区冰川水（补给11．3％），融雪水（36．1％），降水是其必要的补给。从360年重建年径流可知，平水年频率57．7％，偏丰和特丰年较少（17．4％，1．7％），偏枯年23．2％特枯年为0。     

THE MODELING IMPROVEMENT OF HURRICANE ANDREW BY THE TECHNIQUE OF IRREVERSIBLE THERMODYNAMIC OPERATORS*

Although incorporating the horizontal diffusion into the atmospheric governing equations is a part of the dynamics of a model,it is based on the computational consideration originally,which is to overcome the nonlinear aliasing or computational instability and smooth the physical fields at the same time.The generally used forms of the fourth-order diffusion,either linear or nonlinear,however,can not properly describe the real physical diffusion processes and thus affect the accuracy of forecasting and modeling.In this paper,based on the nature of the physical diffusion.the scheme of horizontal diffusion of the MM5 Version 3 is improved according to the second law of thermodynamics which controls the irreversable evolutionary direction of a many-body system and the potential ability of the improvement of the new scheme in modeling accuracy is revealed by introducing the technique suggested in this paper,via a theoretical case and the computational case of the hurricane Andrew that landed on Florida in 1992.     

Earthquake Hazard Assessment in the Oran Region (Northwest Algeria)

This paper deals with the probabilistic seismic hazard analysis carried out in the Oran region, situated in the Northwest of Algeria. This part of Algeriawas historically struck by strong earthquakes. It was particularly affected during theOctober 9, 1790 Oran earthquake of intensity X. The main purpose of this work is to assessseismic hazard on rocks in order to provide engineers and planners with a basic tool for seismicrisk mitigation. The probabilistic approach is used in order to take into account uncertaintiesin seismic hazard assessment. Seismic sources are defined in the light of the most recentresults obtained from seismotectonics analyses carried out in North Algeria.Source parameters such as b-values, slip rate and maximum magnitude are assessed for eachseismic source. The attenuation of ground shaking motion with distance is estimated byusing attenuation relationships developed elsewhere throughout the world (Sadigh et al., 1993; Ambraseys and Bommer, 1991). The two relationships agree well with the local data. Differentchoices of source parameter values and attenuation relationships are assigned weights in alogic tree model. Results are presented as relationships between values of peak groundacceleration (PGA) and annual frequency of exceedance, and maps of hazard for returnperiods of 200 years and 500 years. A maximum peak ground acceleration of 0.42 g is obtainedfor the Oran site for a return period of 500 years.     

ZC油田活性剂驱效果评价研究

通过实验物理模拟，确定HABS磺酸盐型阴离子表面活性剂作为化学驱三次采油的驱油剂，在ZC油田进行了为期一年的矿场先导性试验并做出效果评价，确证HABS表面活性剂驱在ZC油田起到了稳油控水、增产挖潜的作用，有明显的经济效益。     

密度计法试验土用量规定的讨论

通过对密度计法颗粒分析用土量的对比试验及各国有关标准的比较，可以认为国标的有关规定有待修改、完善。     

螺旋板载荷试验资料整理若干问题探讨

螺旋板载荷试验对获取地下水位以下土层的工程参数具有无可比拟的优势 ,但在试验资料的整理分析方面 ,尚有若干问题需要解决。在大量试验的基础上 ,对这些问题进行了有益的探讨。     

Short-range order of Fe2+ in sphalerite by 57Fe Mössbauer spectroscopy and magnetic susceptibility

An extensive study of natural and synthetic Fe-bearing sphalerites (Fe-content ranging from 0.005 afu to 0.250 afu) has been carried out through the combined investigations of the temperature dependence of the magnetic susceptibility and of the ⁵⁷Fe Mössbauer spectroscopic features. Magnetic susceptibility measurements evidence, in the low temperature regime, the presence of clustered Fe even in the most diluted samples, whereas all the Mössbauer spectra are described in terms of variable proportions of three components, namely one single and two doublets absorption, centred at the same isomer shift, relative to Fe ions and to different Fe clusters, respectively. The comparison of all the experimental results points out a self-affinity of Fe ions in sphalerite favoured by the superexchange interaction, which stabilises the formation of clusters even in diluted samples and may be related to both macroscopic inhomogeneous distribution and crystal zoning.     

参数法在悬臂式挡土墙底板尺寸设计中的应用

通过对悬臂式挡土墙设计特点的分析 ,提出了运用参数法进行墙趾板和墙踵板截面的设计计算 ,并进一步探讨了地基承载力对底板尺寸的影响。算例表明 ,该方法能简化设计过程 ,所得到的结果更加合理     

An estimate of probabilistic seismic hazard for five cities in Greece by using the parametric-historic procedure

A probabilistic procedure was applied to assess seismic hazard for the sites of five Greek cities (Athens, Heraklion, Patras, Thessaloniki and Volos) using peak ground acceleration as the hazard parameter. The methodology allows the use of either historical or instrumental data, or a combination of both. It has been developed specifically for the estimation of seismic hazard at a given site and does not require any specification of seismic sources or/and seismic zones. A new relation for the attenuation of peak ground acceleration was employed for the shallow seismicity in Greece. The computations involved the area- and site-specific parts. When assessing magnitude recurrence for the areas surrounding the five cities, the maximum magnitude, m_max, was estimated using a recently derived equation. The site-specific results were expressed as probabilities that a given peak ground acceleration value will be exceeded at least once during a time interval of 1, 50 and 100 years at the sites of the cities. They were based on the maximum peak ground acceleration values computed by assuming the occurrence of the strongest possible earthquake (of magnitude m_max) at a very short distance from the site and using the mean value obtained with the help of the attenuation law. This gave 0.24 g for Athens, 0.53 g for Heraklion (shallow) and 0.39 g Heraklion (intermediate-depth seismicity), 0.30 g for Patras, 0.35 g for Thessaloniki and 0.30 g for Volos. In addition, the probabilities of exceedance of the estimated maximum peak ground acceleration values were calculated for the sites. The standard deviation of the new Greek attenuation law demonstrates the uncertainty and large variation of predicted peak ground acceleration values.