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161.
Prediction and verification of earthquakes induced by the Xiluodu hydropower station reservoir 下载免费PDF全文
Research has been conducted on reservoir-induced earthquakes in China since the Xinfengjiang reservoir-induced earthquakes in the 1960s. Regulations now require the risk of reservoir-induced earthquakes to be evaluated in the pre-research stage of all hydropower projects. Although nearly 40 cases of reservoir-induced earthquakes have been reported in China, analyses comparing the changes in seismic activity following reservoir impoundment with predictions are rare. In this study, we compared seismic activities observed in the reservoir area before and after the impoundment of the Xiluodu hydropower station in terms of the spatial distribution, frequency, and focal depths of the earthquakes, and clarified the correlation between their frequency/timing and reservoir level after impoundment. We then concluded that the seismic events in the head region were karst-type earthquakes, while those in the second segment of the reservoir were tectonic earthquakes. The spatial distribution of the earthquake epicenters and the seismic intensities validated some of the results for the reservoir-induced seismic risk assessment for the Xiluodu hydropower station, indicating that the proposed earthquake triggers and predictive models are reasonable. This study can provide a valuable reference for investigating the mechanism (s) of reservoir-induced earthquakes, revising reservoir-induced earthquake hazard assessment codes, and predicting the hazard zones of reservoir-induced seismicity under similar conditions. 相似文献
162.
为解决长久以来因科普宣传和地震信息来源纷杂、发布渠道分散、形式内容多样而造成的信息不统一、不规范的现实问题,结合多媒体网络信息技术,设计和实现了一套基于DMB的地震信息综合发布系统。阐述了该系统的整体构架、技术特点、模块功能及部署运行后出现问题的解决思路,并对该系统的优势进行了分析。 相似文献
163.
高铁高砷地下水严重威胁饮水质量,曝气-砂滤法因处理效果好且成本低在农村地区得到广泛应用。砂滤过程石英砂表面富集铁和砷后需定期更换,然而废弃石英砂堆置具有砷释放风险。本文以江汉平原某水厂砂滤池废弃石英砂为研究对象,采用激光剥蚀-等离子体质谱(LA-ICP-MS)、拉曼光谱(Raman)、X射线衍射(XRD)和分步化学提取等手段,研究了砂样中的Fe和As含量及形态分布。结果表明,砂粒表面形成了一层厚度为20100 μm的高铁砷薄层,薄层内部Fe和As含量显著高于两侧,Fe和As分布高度相关(R2=0.985)。砂样表面铁矿物以无定型/弱结晶型为主,同时检出赤铁矿和臭葱石等矿物。砂样中Fe和As总含量分别为20.1 mg/g和53.4 μg/g。砂样表面铁主要以易溶解态、碳酸盐结合态和易还原态为主,As主要吸附在铁矿物上。研究区降雨充沛,当废弃石英砂遭遇雨水冲刷或淹没时,可能导致铁砷薄层中As解吸或随Fe矿物还原溶解而释放。 相似文献
164.
黄沅 《地球科学与环境学报》1997,(2)
本研究对地球起源与海陆成因及变迁等问题进行论证,以物质运动基本原理(物质集中、能量释放)提出:“地球中间膨胀(释能)造陆、大陆向两极移动”的新学说(1982年)。认为地球成因与演变同其它天体一样,是在星际物质集中下发生的能量释放过程。由于地球水分子多,能量释放缓慢亦使陆地生成缓慢,陆地是其后产生的。陆地主要生成在地球自转离心力、日月引力、地球张力(内能膨胀)的最强区。这样不仅使地球会演变成椭球体,同时膨胀区大陆在向两极方向移动中,便发生海陆变迁与地表形变。 相似文献
165.
166.
The biologically mediated weathering of the ocean crust has received increasing attention in recent decades, but the rates and the possible mechanism of elemental release during microbe–basalt interactions occurring below the seafloor have not been studied in detail. In this study, we established an experimental weathering study of seafloor natural basaltic glass comparing the effect of microbial activity (Pseudomonas fluorescens) in P-rich and P-poor media with parallel controls containing either nonviable cells or organic acid. The changes in the chemical parameters, including pH, bacterial densities, and ion concentrations (Ca, Mg, Si, Mn, Al, Fe, and P) in the solution, were examined during the different batch experiments. The results showed that the pH decreased from 7.0 to 3.5 and the bacterial density increased from 105 to 108 cells/ml during the first 120 h, and the cell numbers remained constant at 108 cells/ml and the pH increased from 3.5 to 6 between 120 h and 864 h in the P-bearing reactors containing bacteria. In contrast, during all the experimental time, the pH remained close to neutral condition in the abiotic control systems and the dissolution rates increased markedly with a decrease in pH and became minimal at near-neutral pH in P-bearing reactors containing bacteria, where Ca, Si, and Mg release rates were 2- to 4-fold higher than those obtained in chemical systems and biotic P-limited systems. Furthermore, the surfaces of the natural volcanic glass from the biotic systems were colonized by bacteria. Simultaneously, the etch pits were observed by Scanning Electron Microscope, which further indicate that the bacteria may promote the mineral dissolution for energy gain. Some elements (e.g., Fe, Mn, and Al) releasing from natural volcanic glass are likely an important source of the elemental budget in the ocean, and thus the element release and its possible mechanism conducted in this experimental study have potential implications on the biogeochemical cycling process in the Mid-Oceanic Ridge setting. 相似文献
167.
The Chang'E-1 and Chang'E-2 missions have successfully obtained a huge amount of ltmar scientific data, through the seven onboard instruments including a CCD stereo camera, a laser altimeter, an interference imag- ing spectrometer, an X-ray spectrometer, a microwave radiometer, a high-energy particle detector and a solar-wind ion detector. Most of the Chang'E data are now publicly available to the science community, and this article serves as an official guide on how these data are classified and organized, and how they can be retrieved from http://159.226.88.59:7779/CE1OutENGWeb/. This article also presents the detailed specifications of various instru- ments and gives examples of research progress made based on these instruments. 相似文献
168.
熔融制样X射线荧光光谱法测定铜矿石中16种主次量元素 总被引:1,自引:1,他引:0
铜矿石类型繁多,矿石赋存状态各异,成分复杂。在现有的铜矿石熔融制样X射线荧光光谱(XRF)分析方法中,选取标准物质个数和矿石类型少、分析范围宽,与实际样品类型相差太大,且制备的熔融片质量不高。本文选用铜含量既有良好浓度变化范围,又符合铜矿石常见含量的包括铜金银铅锌钼铜镍等各类矿石的24个标准物质,以四硼酸锂-偏硼酸锂-氟化锂为混合熔剂,熔剂与样品质量比为30:1,以溴化锂为脱模剂,改进样品预处理方式,将通常采用样品预氧化后或熔融中加入脱模剂的方式,改进为加入脱模剂后再用混合熔剂完全覆盖的方法制备了高质量的熔融片,建立了XRF测定铜矿石中铜锌铅硅铝铁钛锰钙钾镁钼铋锑钴镍16种元素的分析方法。分析铜矿石国家标准物质GBW 07164、GBW 07169,各元素的精密度(RSD)为0.1%~5.4%。分析国家标准物质GBW 07163(多金属矿石)、GBW 07170(铜矿石)的测定值与标准值相符;分析实际铜矿石样品,铜锌铅钼铋锑钴镍的测试结果与电感耦合等离子体发射光谱法和其他方法的测定值相符。本文方法扩大了基体的适应性,提高了实际应用价值。 相似文献
169.
针对宁夏中部干旱带压砂地土壤肥力下降、灰绿板岩矿质元素淋溶释放规律不明等问题,通过室内模拟灰绿板岩冻融干湿循环交替试验,采用修正的Elovich方程、抛物线方程、双常数速率方程、一级动力学方程对各矿质元素的累积释放曲线进行拟合,研究不同粒径板岩在冻融干湿循环作用下的释放动力学特征及最优动力学方程。结果表明:两种粒径灰绿板岩淋溶液中矿质元素淋溶总量随循环次数增大而增大,1 cm粒径灰绿板岩矿质元素累积淋溶总量、淋溶速率在不同循环次数下均大于3 cm粒径。灰绿板岩矿质元素淋溶释放是多因素共同控制的物理、化学过程,其释放过程可大致分为快速反应阶段和反应趋于平衡阶段;压砂地土壤中Ca、K、Mg、P元素的供给量运用修正的Elovich方程预测结果较好,抛物线方程更适用于描述S元素的释放规律。研究结果可为宁夏中部干旱带旱作农田土壤肥力调控提供决策参考。 相似文献
170.