Groundwater Microbial Communities Along a Generalized Flowpath in Nomhon Area,Qaidam Basin,China

Spatial distribution (horizonal and vertical) of groundwater microbial communities and the hydrogeochemistry in confined aquifers were studied approximately along the groundwater flow path from coteau to plain in the Nomhon area, Qinghai‐Tibet plateau, China. The confined groundwater samples at different depths and locations were collected in three boreholes through a hydrogeological section in this arid and semi‐arid area. The phylogenetic analysis of 16S rRNA genes and multivariate statistical analysis were used to elucidate similarities and differences between groundwater microbial communities and hydrogeochemical properties. The integrated isotopic geochemical measurements were applied to estimate the source and recharge characteristics of groundwater. The results showed that groundwater varied from fresh to saline water, and modern water to ancient water following the flowpath. The recharge characteristics of the saline water was distinct with that of fresh water. Cell abundance did not vary greatly along the hydrogeochemical zonality; however, dissimilarities in habitat‐based microbial community structures were evident, changing from Betaproteobacteria in the apex of alluvial fan to Gammaproteobacteria and then to Epsilonproteobacteria in the core of the basin (alluvial‐lacustrine plain). Rhodoferax, Hydrogenophaga, Pseudomonas, and bacterium isolated from similar habitats unevenly thrived in the spatially distinct fresh water environments, while Sulfurimonas dominanted in the saline water environment. The microbial communities presented likely reflected to the hydrogeochemical similarities and zonalities along groundwater flowpath.     

琼中地震台连续重力显著异常分析

2014年以来,琼中基准地震台连续重力观测数据出现较为显著的零漂转折加速和数据放大异常。经仪器观测系统检查、台站观测环境调查、数据分析等核实操作,分析认为:(1)零漂转折加速异常系观测环境影响所致;(2)数据放大异常系网络数据采集器故障所致。因此,2次异常均非地震地球物理异常。此类异常干扰判别可为其他重力台站观测数据分析提供参考。     

Adsorption of Complex Pollutants from Aqueous Solutions by Nanocomposite Materials

In view of water pollutants becoming more complex, both anionic and cationic pollutants need to be removed. The multi‐pollutants simultaneous removal is paid more and more attention. Hence, development composite materials for treatment complex wastewater are the aim of this study. In this research, iron–nickel nanoparticles deposited onto aluminum oxide (α‐Al₂O₃) and carbon nanotubes (CNTs) to form nanocomposite materials Fe–Ni/Al₂O₃ and Fe–Ni/CNTs, respectively, were used as adsorbents. The adsorption capacities of Fe–Ni/Al₂O₃ and Fe–Ni/CNTs for AO7, HSeO, and Pb²⁺ were observed to be 5.46, 8.28, 27.02, and 25.6 mg/g, 15.29 and 17.12 mg/g, separately. The composite materials with negative charges were superior in adsorption of anionic pollutants. Using orthogonal experimental design and analysis of variance to co‐treat dye AO7, HSeO and Pb²⁺ in aqueous solutions, seven testing factors were included: (1) adsorbent types, (2) amount of iron, (3) solution pHs, (4) AO7 concentrations, (5) Pb²⁺ concentrations, (6) HSeO concentrations and (7) reaction time. The experimental results showed that the removal of complex pollutants AO7, HSeO, and Pb²⁺ on Fe–Ni/CNTs could reach up to 90% in the optimal treatment conditions. When using Fe–Ni/CNTs as the adsorbent, the sorption isothermals were well fitted in the Freundlich isotherm, and R² could reach up to 0.98.     

山西临汾盆地及其周缘现今地震活动特征与地震危险性分析

依据地震地质构造和断裂带几何特征,将临汾盆地及其周缘划分为6个研究区域,运用近27年经过精确定位的区域台网地震资料,采用多个地震活动参数值的组合,结合震源深度分布、历史强震背景,分析临汾盆地及其周缘各研究区的现今活动状态。结果表明,现今应力水平较高的3个区域分别为洪洞—临汾凹陷、侯马凹陷和峨眉台地。其中,洪洞—临汾凹陷为1303年洪洞8.0级地震的破裂区,现今应力水平仍然较高,其中深部出现的小震活动稀疏段可能表明其正处于破裂区的恢复阶段;侯马凹陷至峨嵋台地北缘自有史料记载以来,没有记录到M6以上地震,现今地震活动特征显示其处于较高应力水平下的相对闭锁状态,属于未来强震的危险区段;灵石隆起、辛置凸起和襄汾凸起现今应力水平相对较低,以中小地震活动为主要特征,强震危险性较小。     

超声激励低渗煤层甲烷增透机理

超声激励增透煤层是一种不受甲烷储层地质条件和气源特性限制,具有普遍应用价值的增采技术.但由于煤岩致密、裂隙发育,煤岩孔隙度存在多尺度效应,受储层介质尺度效应影响的增透促吸机理尚不明确.本文通过CT观测实验和渗透率测定实验,对超声波作用下煤样不同尺度裂隙发展规律进行了分析,对比测定超声作用煤样渗透率变化规律,建立了超声增透煤层甲烷渗透率的修正公式.研究结果表明:CT观测实验很好地证明了超声的机械震碎作用;在声场衰减范围内,煤体损伤和机械震碎作用明显;超声波作用后的煤层渗透率有平均135%～169%的提高.研究工作为超声激励增加煤层的渗透率提供了实验基础.     

海南岛陆地区重力场变化与地震关系研究

研究反映测区重力场变化的两种方式:重力段差的时序变化图及测区重力场的平面变化图.结果表明,地震的孕育和发生伴随着重力场的变化.     

土洞对岩溶场地地震动参数影响研究

为研究土洞对岩溶场地地表地震动参数的影响,选取广西桂林市某岩溶场地,分析土洞的存在对地表地震动峰值和频谱的影响。依据场地地震反应分析理论,建立包含土洞与不包含土洞的有限元模型并进行地震反应分析,应用计算结果中1-3层土体表面中心点的地震动,作为原始信号输入,进行FFT(离散傅氏变换的快速算法)转换,得到场地各层土体表面中心点的频谱分析图。分析结果表明:(1)土洞的存在对地表峰值速度和峰值位移影响相对较小,对峰值加速度影响较大,且越上层土体地震动参数受土洞影响越大;(2)包含土洞的加速度频域分布峰值大于不包含土洞的岩溶场地,并且包含土洞与不包含土洞岩溶场地主要(卓越)频率分布在0-5Hz范围,分布较集中,峰值加速度对应的频率在2.5Hz附近。     

阿尔芬波总磁场存在漂移趋势时磁通门磁强计在轨标定的优化方法

高精度的磁场测量对深空探测具有重要意义,然而卫星上磁通门磁强计的磁补偿值会随着时间缓慢变化,需要进行在轨标定.近期,一种新的在轨标定方法被提出,即Wang-Pan方法.该方法发现阿尔芬波动存在一个线性度高的最优补偿曲线,利用多个波动的最优补偿曲线可计算出磁强计的磁补偿.然而,该方法没有考虑所选波动事件的总磁场存在漂移趋...     

Effects of variable attribute weights on landform classification

This paper focuses on the attribute weight issue and advocates use of modi?able attribute weights in terrain‐based environmental analysis and classi?cation. A question was asked: ‘How much will the result of a terrain‐based environmental analysis be affected if the weights of used terrain attributes are changed?’ The literature on landform classi?cation and the fuzzy k‐means method was reviewed in particular to help clarify the background and importance of this weight assignment issue. As an example, the effects of modifying attribute weights were evaluated for fuzzy k‐means landform classi?cation in a case study area. A total of 102 classi?cations were compared with each other and with a soil map, and comparison methods were speci?cally designed to evaluate the differences between these classi?cations. The results show that fuzzy k‐means landform classi?cation is sensitive to weight adjustments of adopted terrain attributes. The sensitivity is particularly high when the attribute weights started to be tuned away from the standard (i.e. uniform) weight of one. Better matching between landform classi?cation and a soil map may be produced when attribute weights are tuned. In all, we advocate the widespread adoption of an exploratory attitude in assigning attribute weights for environmental analysis and classi?cation. Copyright © 2006 John Wiley & Sons, Ltd.     

地下钻杆透层天线

对于有耗分层媒质中的垂直透层天线，建立了Ｈａｌｌｅｎ积分方程分析法的一般理论以及求取地面电场和电压的计算方法．作为应用实例，给出了地下３层媒质中钻杆天线上的电流积分方程，并对典型的地质参数进行了数值计算．所得结果和结论，与已知的理论结果和实验规律吻合。