影响断层带再活动的一些因素的实验研究

很多地震发生在活动断层上。但断层带是否活动并不是一成不变的。目前,在没有大量实测资料的情况下,我们往往还要推断哪些断层是易于活动的。实验与计算结果表明,影响断层再活动的因素为力的方向、力的大小,断层带厚度,断层带物质的力学性质等。这些结果将有助于我们推测活断层。     

金属矿地球物理勘探的三十年

本文给出了三十年来各种地球物理方法在我国普查和勘探金属矿工作中的应用。叙述了一些成功和不成功的事例、经验和教训。 根据我国金属矿地区的地形、地质和成矿条件,提出今后技术发展的方向,强调对新方法的基本研究。     

The Generalized Equation of Consolidation Theory and Its Application

This paper presents a generalized equation of the consolidation theory ,which is applicable to the arbitrary rheological models .The unknown constants of the equation can be determined through the experimental data by semi-analytical and semi-empirical methods .Thus,a new method for settlement calculation is provided     

COULOMB STRESS CHANGE ON ACTIVE FAULTS IN SICHUAN-YUNNAN REGION AND ITS IMPLICATIONS FOR SEISMIC HAZARD

Coulomb stress change on active faults is critical for seismic hazard analysis and has been widely used at home and abroad. The Sichuan-Yunnan region is one of the most tectonically and seismically active regions in Mainland China, considering some highly-populated cities and the historical earthquake records in this region, stress evolution and seismic hazard on these active faults capture much attention. From the physical principal, the occurrence of earthquakes will not only cause stress drop and strain energy release on the seismogenic faults, but also transfer stress to the surrounding faults, hence alter the shear and normal stress on the surrounding faults that may delay, hasten or even trigger subsequent earthquakes. Previously, most studies focus on the coseismic Coulomb stress change according to the elastic dislocation model. However, the gradually plentiful observation data attest to the importance of postseismic viscoelastic relaxation effect during the analysis of seismic interactions, stress evolution along faults and the cumulative effect on the longer time scale of the surrounding fault zone. In this paper, in order to assess the seismic hazard in Sichuan-Yunnan region, based on the elastic dislocation theory and the stratified viscoelastic model, we employ the PSGRN/PSCMP program to calculate the cumulative Coulomb stress change on the main boundary faults and in inner blocks in this region, by combining the influence of coseismic dislocations of the M≥7.0 historical strong earthquakes since the Yongsheng M7.8 earthquake in 1515 in Sichuan-Yunnan region and M≥8.0 events in the neighboring area, and the postseismic viscoelastic relaxation effect of the lower crust and upper mantle. The results show that the Coulomb stress change increases significantly in the south section of the Xianshuihe Fault, the Anninghe Fault, the northern section of the Xiaojiang Fault, the southern section of the Longmen Shan Fault, the intersection of the Chuxiong-Jianshui Fault and the Xiaojiang Fault, and the Shawan section of the Litang Fault, in which the cumulative Coulomb stress change exceeds 0.1MPa. The assuming different friction coefficient has little effect on the stress change, as for the strike-slip dominated faults, the shear stress change is much larger than the normal stress change, and the shear stress change is the main factor controlling the Coulomb stress change on the fault plane. Meanwhile, we compare the Coulomb stress change in the 10km and 15km depths, and find that for most faults, the results are slightly different. Additionally, based on the existing focal mechanism solutions, we add the focal mechanism solutions of the 5 675 small-medium earthquakes(2.5≤M≤4.9)in Sichuan-Yunnan region from January 2009 to July 2019, and invert the directions of the three principal stresses and the stress shape factor in 0.1°×0.1° grid points; by combining the grid search method, we compare the inverted stress tensors with that from the actual seismic data, and further obtain the optimal stress tensors. Then, we project the stress tensors on the two inverted nodal planes separately, and select the maximum Coulomb stress change to represent the stress change at the node. The results show that the cumulative Coulomb stress change increase in the triple-junction of Sichuan-Yunnan-Tibet region is also significant, and the stress change exceeds 0.1MPa. Comprehensive analysis of the Coulomb stress change, seismic gaps and seismicity parameters suggest that more attention should be paid to the Anninghe Fault, the northern section of the Xiaojiang Fault, the south section of the Xianshuihe Fault, the southern section of the Longmen Shan Fault and the triple-junction of the Sichuan-Yunnan-Tibet region. These results provide a basis for future seismic hazard analysis in the Sichuan-Yunnan region.     

海南岛玻璃陨石(雷公墨)裂变径迹年龄的测定

引言许多绝缘固体如塑料、玻璃和天然矿物常常可以记录带电粒子的径迹(这些未经化学蚀刻的径迹可称为潜迹),这是带电粒子在绝缘固体内沿着自己运动的轨迹所造成的辐射损伤区。在天然矿物中所记录的裂变径迹是这类固体核径迹中的一种,它是直径大约50(?),长约20微米的柱形辐射损伤区,最初只能用高倍的电子显微镜才能观察到。     

东亚地区沙尘气溶胶影响硫酸盐形成的模式评估

利用STEM-II三维区域大气化学模式,耦合沙尘气溶胶表面相过程,研究了1994年3月1日至14日间东亚地区沙尘气溶胶对硫酸盐形成的影响。结果表明,SO2气体在沙尘气溶胶表面上进行的非均相氧化过程是硫酸盐形成的一条重要途径,由这条途径提供的硫酸盐占其总浓度的20%～50%。 并发现在模拟时段,沙尘暴过程主要影响沙尘源地下游的中国东部地区硫酸盐的分布,使得那里的硫酸盐浓度增加60%以上。     

里下河地区梅雨量的可能异常和变化规律

本文利用50年代以来的观测资料,分析了里下河地区梅雨期降水量的基本特征,对若干年一遇的可能梅雨量异常和变化规律进行了初步研究。得出里下河地区梅雨量具有5年和3年周期的变化,并且阜宁的降水量是异常小中最小的,兴化的降水量是异常大中最大的。     

福建省花卉产业发展SWOT分析及对策研究

福建省的花卉产业发展存在着一定的优势(Strengths)、劣势(Weaknesses)、机遇(Opportunities)、威胁(Threats)因素,优势和劣势、机遇和威胁之间也存在着相互转化的互动关系,利用福建省近几年的花卉产业发展资料,运用SWOT法分别对福建省花卉产业发展的优势、劣势、机会和威胁进行具体分析,结合福建省的实际情况,在花卉生产管理、区域特色优势品种规划、花卉生产和经营思路、花卉基地、花卉协会的行业指导、花卉发展环境等方面提出了一些的具体对策和建议.     

关于黄土碳酸盐与气候环境关系探讨

黄土中碳酸盐与气候环境密切相关。从碳酸盐的成因看，干冷的气候利于原生碳酸盐的保存，而温湿的气候使大量的次生碳酸盐产生。碳酸盐的存在形式与降水量多少有关，降水量大可形成结核层和钙板等，而降水量小则形成各种胶膜。胶膜中各种不同形态的方解石胶膜又可反映不同的气候条件。黄土一古土壤中形成的碳酸盐实际上在古土壤期形成的碳酸盐要高于黄土期形成的，只是由于古土壤期强烈的风化淋溶作用，大量的碳酸盐从古土壤中淀积到下伏的黄土层中。黄土中CaCO3的淀积可分为连续淀积和不连续淀积两类。依据淀积深度和降水量的关系，可建立二者定量的关系。从黄土碳酸盐的不同方面，得到其与气候环境关系较为全面的认识。     

A new solution for a partially penetrating constant‐rate pumping well with a finite‐thickness skin

A mathematical model describing the constant pumping is developed for a partially penetrating well in a heterogeneous aquifer system. The Laplace‐domain solution for the model is derived by applying the Laplace transforms with respect to time and the finite Fourier cosine transforms with respect to vertical co‐ordinates. This solution is used to produce the curves of dimensionless drawdown versus dimensionless time to investigate the influences of the patch zone and well partial penetration on the drawdown distributions. The results show that the dimensionless drawdown depends on the hydraulic properties of the patch and formation zones. The effect of a partially penetrating well on the drawdown with a negative patch zone is larger than that with a positive patch zone. For a single‐zone aquifer case, neglecting the effect of a well radius will give significant error in estimating dimensionless drawdown, especially when dimensionless distance is small. The dimensionless drawdown curves for cases with and without considering the well radius approach the Hantush equation (Advances in Hydroscience. Academic Press: New York, 1964) at large time and/or large distance away from a test well. Copyright © 2007 John Wiley & Sons, Ltd.