北祁连早古生代大地构造演化

早古生代北祁连是一个陆间微洋盆。震旦纪时,北祁连开始从华北板块中解体出来。主要裂谷作用发生于寒武世。北祁连地槽主要闭合期为晚奥陶世和早、中志留世。晚志留世和早泥盆世经历了复杂的消减作用。     

Transport and sedimentation of particles in a fluid flow

A simple two-dimensional random walk model is developed for the motion of a particle in a fluid flow. Some earlier results for the persistent injection of particles into the flow are extended, and the distribution of the maximum number of particles in suspension over the period (0,t) is derived.     

中国西北C-3植物的碳同位素组成与年降雨量关系初探

 本文对不同年降雨量环境下生长的藜、独行菜、魁蓟和平车前这4种常见C-3植物的δ¹³C进行了分析,发现这4种C-3植物的δ¹³C组成都表现出随年降雨量减少而变重的趋势,其中藜和独行菜的碳同位素组成对降水变化的响应相对要较其它2种植物强烈得多。藜、独行菜和魁蓟的δ¹³C组成与年降雨量有显著的线性关系,平车前碳同位素组成与年降雨量没有显著的相关性,表明藜、独行菜和魁蓟的δ¹³C组成可作为年降雨量的替代性指标,平车前的δ¹³C组成不能作为年降水的替代性指标。     

多维地震动各方向相关性对拱坝动应力的影响

本文将随机振动的虚拟激励法与拱坝-地基动力相互作用FE-BE-IBE时域模型结合，发展了一个可以考虑多维随机地震动作用下的拱坝动力响应计算模型，并用Monte Garlo方法对模型进行了验证，计算结果表明，地震动分量的相关性对结构的动力响应存在一定影响，合理考虑地震动各方向分量的相关性可以更好地计算实际地震作用下的拱坝动力响应。     

On the Bayesian analysis of the earthquake hazard in the North-East Indian peninsula

The Bayesian extreme-value distribution of earthquake occurrences has been used to estimate the seismic hazard in 12 seismogenic zones of the North-East Indian peninsula. The Bayesian approach has been used very efficiently to combine the prior information on seismicity obtained from geological data with historical observations in many seismogenic zones of the world. The basic parameters to obtain the prior estimate of seismicity are the seismic moment, slip rate, earthquake recurrence rate and magnitude. These estimates are then updated in terms of Bayes’ theorem and historical evaluations of seismicity associated with each zone. From the Bayesian analysis of extreme earthquake occurrences for North-East Indian peninsula, it is found that for T = 5 years, the probability of occurrences of magnitude (M _w = 5.0–5.5) is greater than 0.9 for all zones. For M _w = 6.0, four zones namely Z1 (Central Himalayas), Z5 (Indo-Burma border), Z7 (Burmese arc) and Z8 (Burma region) exhibit high probabilities. Lower probability is shown by some zones namely␣Z4, Z12, and rest of the zones Z2, Z3, Z6, Z9, Z10 and Z11 show moderate probabilities.     

Non-stationary random vibrations of a shear beam under high frequency seismic effects

Band-limited, non-stationary random vibrations of a shear beam are studied in order to investigate high frequency seismic effects on building structures. A solution for the evolutionary spectral density of the shear beam response to a time segment of band-limited white noise is given in a closed form. The root mean square (rms) and peak response of the shear beam are studied for two characteristic frequency bands: the conventional 1–4 Hz and higher frequency 4–16 Hz, characteristic for rockburst ground motion. Applying the criterion of equal excitation intensity with constant rms velocity, both responses are analyzed in detail and compared. The “switching off” fundamental mode for high frequency excitations results in characteristic overshoot of the stationary response level by the non-stationary rms response and an amplification of the response in the upper part of the shear beam.     

开挖边坡随机楔体稳定分析与加锚优化方法

随机楔体的破坏是岩石开挖边坡中常见的破坏类型之一，在对组成楔体的结构而调查统计的基础上，应用随机模拟的方法，生成开挖边坡的三维裂隙网络，进一步运用随机搜索方法与块体理论，搜索出边坡面上的随机楔体，进行楔体的稳定分析，采用风险设计的理论，建立系统锚杆的优化设计方法，将研究结果应用于小湾水电站进水口开挖边坡的稳定分析与锚固优化设计中，得到了较为可信的结果。     

A Report on a Biotite-Calcic Hornblende Geothermometer

This paper presents a biotite-calcic hornblende geothermometer which was empirically calibrated based on the gamet-biotite geothermometer and the gamet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560-800℃ (T) and 0.26-1.4 GPa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from the literature. Biotite was treated as symmetric Fe-Mg-AlVI-Ti quaternary solid solution, and calcic hornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer may rebuild the input garnet-biotite temperatures well within an uncertainty of ±50℃. Errors of ±0.2 GPa for input pressure, along with analytical errors of ?% for the relevant mineral compositions, may lead to a random error of ±16℃ for this thermometer, so that the thermometer is almost independent of pressure estimates. The thermometer may clearly discriminate different rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidence level. It is assume     

测量地应力的新方法

论述了用赤平投影学方法分析确定地应力的主方向，用Kaiser效应测量地应力大小。将两者有机结合起来可以克服Kaiser效应测量地应力时，主应力方向难以确定的最大缺点。通过和传统现场地应力测量方法比较，表明该法具有更为简单，更为经济，准确度高等优点，便于大量测量，以寻求工程地区地应力变化规律。     

3D裂隙网络随机模拟及其工程应用研究

岩体中存在的大量随机分布的裂隙对岩体的工程性质及稳定性有着极其重要的影响。传统的工程地质研究方法难以客观地描述其空间分布特征。应用概率与统计学的理论 ,通过统计分析得到裂隙的分布规律性 ,采用随机模拟的方法实现与统计分布相适应的裂隙网络是研究随机裂隙宏观特征的有效途径。通过模拟所得的 3D裂隙网络 ,进一步研究了裂隙的连通特征及工程开挖面上的稳定分析与加固措施优化的方法