大直径硬岩环状取芯钻具的试验研究

在分析了国内外大直径基岩孔钻进取芯方法的基础上,提出了一套低能耗、高效率、低造价的大直径硬岩环状取芯钻具,设计制作了样机,并进行了样机试验.试验结果表明:该设计方案、工艺可行,达到了预期设计目标,为大直径硬岩取芯施工提供了一种新的机具.     

地震重现时间间隔概率分布函数选择的必要条件

地震重现时间间隔的分布规律研究对于短期和中长期地震预测、地震灾害预防和救援有着重要的理论和实际意义,如果能够确定地震重现时间间隔的概率密度函数(probability density function-pdf),则在统计学的意义上,能够对地震再次发生的概率进行评估和预测.在地震重现时间间隔的pdf研究中,一个核心问题是如何判断某个pdf是否能够有效地描述地震重现时间间隔分布特征.作者提出利用特征地震重现时间间隔数据的变化系数(COV)与其偏度(S),变化系数与其峰度(K)的相关关系对所选择的pdf的适用性进行判别.研究表明,常用的一些概率密度函数(对数正态分布、gamma分布、Weibull分布和指数分布)并不合适作为描述特征地震的重现时间间隔分布的数学模型.     

东秦岭寒武纪构造古地理概况

本文提出寒武纪以商丹断裂带为界,东秦岭地区北部属中朝板块南部陆缘区,为主动大陆边缘,以双列岛弧为特征;中部和南部属杨子板块北部陆缘区,由两隆(大陆区北缘和中秦岭微板块)—凹(南秦岭盆地)组成,为被动大陆边缘。     

The impact of sulfate reduction on the distribution of methylmercury in reservoirs in the city of Guiyang

In this paper, the relationship between sulfate reduction potential and mercury methylation potential was studied in the Aha, Baihua and Hongfeng reservoirs from Guiyang City. The methylmercury (MeHg) concentrations of lake water in the Aha Reservoir were greatly elevated as compared to those of the Hongfeng and Baihua reservoirs, which was correlated with its distinctly high SRB abundance, SO42-, and S2- concentrations. Among the three reservoirs, however, the highest MeHg was observed in in the top several centimenters of pore water profile in the Hongfeng Reservoir where the lowest S2- in pore water occurred. The distributions of MeHg in lake water and pore water showed the highest methylation potential occurred at water-sediment surface for the Aha Reservoir and the in the top several centimenters of sediments for the Hongfeng Reservoir. It is guessed that the highest mercury methylation only occurs at the sites with certain sulfide concentrations.     

The Synthetic Evaluating Method of Shale Oil sweet spot in the Jiyang Depression

<正>1 Introduction During the processes of shale oil-exploration in the Jiyang depression,more than 700 exploratory wells going through the mudstone layers appeared oilgas shows,while only 40 of them had commercial hydrocarbon flows in the end.Meanwhile,increasing oil-gas production of     

锡矿山超大型锑矿床流体成矿作用及矿床成因

本文对锡矿山流体包裹体,稳定同位素,活动性微量元素,硅化作用及元素存在相态和淋滤率进行了详细研究。揭示了其成矿流体来源于深循环大气降水,是一种中低温,低盐度的弱碱性流体,成矿物质来自于前泥盆系地层,主要是震旦,寒武系地层,区域地层可能经受过大规模的流体运移作用。得出了锡矿山锑矿是由深循环大气降水林滤基底地层的成矿物质后形成含矿流体沿主断裂向上运移至浅部,由于物理化学条件的改变导致锑沉淀成矿的结论。     

基于ACCRBF网络的多层砖房震害预测

针对传统震害预测方法逐栋抽样计算建筑物抗震性能的不足,本文提出了一种基于蚁群聚类径向基(ACCRBF)网络模型的建筑物震害预测方法。依据不同地震动峰值加速度下多层砖房的实际震害资料,对模型进行训练,在模型的输入和输出之间建立映射关系,并利用这种映射关系对未知样本进行分类,实现对多层砖房的震害分析和预测。模型的输入为反映结构的震害影响因子,输出为给定的地震动峰值加速度下结构震害等级。研究表明,基于ACCRBF网络模型的多层砖房震害预测结果与震害实例基本吻合,具有推广应用价值。     

Precise orbit determination of BeiDou constellation: method comparison

Chinese BeiDou navigation satellite system is in official service as a regional constellation with five geostationary earth orbit (GEO) satellites, five inclined geosynchronous satellite orbit (IGSO) satellites and four medium earth orbit (MEO) satellites. There are mainly two methods for precise orbit determination of the BeiDou constellation found in the current literatures. One is the independent single-system method, where only BeiDou observations are used without help from other GNSS systems. The other is the two-step GPS-assisted method where in the first step, GPS data are used to resolve some common parameters, such as station coordinates, receiver clocks and zenith tropospheric delay parameters, which are then introduced as known quantities in BeiDou processing in the second step. We conduct a thorough performance comparison between the two methods. Observations from the BeiDou experimental tracking stations and the IGS Multi-GNSS Experiment network from January 1 to March 31, 2013, are processed with the Positioning and Navigation Data Analyst (PANDA) software. The results show that for BeiDou IGSO and MEO satellites, the two-step GPS-assisted method outperforms the independent single-system method in both internal orbit overlap precision and external satellite laser ranging validation. For BeiDou GEO satellites, the two methods show close performances. Zenith tropospheric delays estimated from the first method are very close to those estimated from GPS precise point positioning in the second method, with differences of several millimeters. Satellite clock estimates from the two methods show similar performances when assessing the stability of the BeiDou on board clocks.     

Embedding eco-friendly and smart technology features in affordable housing for community happiness in Malaysia

GeoJournal - Two phases of study are involved in this research: first, the sales strategies for affordable houses embedded with eco-friendly and smart technology features; and second, the impact of...