New paleomagnetic results from Ceno-Mesozoic volcanic rocks along southern rim of the Tarim Basin,China*

Paleomagnetic samples were collected from four localities located in the southern rim of the Tarim basin. The samples were taken from volcanic rocks erupted between Jurassic and Quaternary. Detailed analysis of all samples has been carried out with progressive thermal demagnetization. A characteristic remanence (ChRM) with higher unblocking temperature has been isolated from all samples. The pole position from the middle Jurassic is at 52.5°N, 187.9°E(dp = 3.7°,dm =6.5°); the directions of the ChRM of Cretaceous correspond to a paleopole at 69.7°N, 211.6°E (dp = 9.8°,dm = 15.9°); the Quaternary pole from the Pulu site is at 79. 9°N, 183.1°E(dp = 1.6°.dm =2.4°). On the basis of these new paleomagnetic data, tectonic evolution of Tarim block is presented.

     

用尾波干涉法监测介质波速变化研究进展

Multiply scattered waves are sensitive to media changes owing to the effect of repeated sampling,superposition and amplification. Based on this characteristic,small-medium changes could be detected by using coda wave interferometry. In recent years,coda wave interferometry has been widely used in estimating velocity variation with high precision in areas such as seismology and non-destructive testing. This paper systematically presents the principle and research status of coda wave interferometry,and especial focus is placed on the research of media velocity variations by using repeating earthquakes,artificial sources,and ambient noise. Applications of coda wave interferometry can contribute to the more subtle understanding of dynamic evolution process in the medium.     

湖北宜昌×××条带状磷块岩选矿试验研究

×××磷矿属海相沉积型磷块岩矿床,主要具有胶状泥晶结构和磷质砂屑结构,以条带状构造为主。采用单一反浮选选矿工艺,使用硫酸为抑制剂、中化地质矿山总局地质研究院研制的K-02为捕收剂,在常温条件下取得较好的选矿工艺指标。进行了实验室重液浮沉试验。     

云南拱丁金矿中富银黄铜矿的初步研究

富银黄铜矿发现于云南省沧源佤族自治县斑洪乡拱丁金矿石英脉内,该矿是以金(银)为主的多金属硫化物矿床。共生矿物有自然金、银金矿、自然银、银黝铜矿及辉锑铅银矿等。     

Propagation and localization of wave in multi‐span Timoshenko beams on elastic foundations under moving harmonic loads

Wave propagation and localization in ordered and disordered multi‐span beams on elastic foundations due to moving harmonic loads are investigated by using the transfer matrix methodology. The transfer matrix, as a function of the frequency and velocity of the moving harmonic load, of the periodic beam is formulated in a coordinate system moving with the load. The expressions of critical velocities, cut‐off frequency of an associated uniform beam without discrete spaced supports, are determined through the analysis of the wavenumbers, and the dynamic responses of the beam are also examined. For the ordered and disordered case, the propagation constants and localization factors are respectively employed to identify the velocity and frequency pass bands and stop bands in order to examine whether the perturbation can propagate along the structure or not. The effects of the periodicity, disorder level, excitation frequency, and moving velocity are studied in detail. The validity of the obtained results is confirmed by evaluating the transverse deformation of the beams through the finite element simulations. Copyright © 2017 John Wiley & Sons, Ltd.     

北京市典型山洪流域暴雨洪水分析

依据北京市1980~2012年间降水摘录资料和洪水摘录资料,选择张家坟流域为典型山洪流域,分析不同量级洪水的雨量、洪量、峰现时间及洪水过程与暴雨之间的关系。分析方法和分析结果为山洪流域的洪水预报提供了一定的借鉴。     

自组织特征映射神经网络在厄尔尼诺事件检验中的应用

对厄尔尼诺事件多因素成因进行了分析。利用自组织特征映射（SOFM）神经网络方法对1973～1994年的全球7级以上地震次数、日食条件、海温距平数据建立了SOFM网络检验模型。对1995~2000年厄尔尼诺事件进行了检验,检验的准确率为83.3% 。     

"黑色"非晶形三价铁羟基氧化物及其对有害物质的吸附

利用硝酸铁与氨水之间的水解反应,生成了一种新的"黑色"非晶形三价铁羟基氧化物 (FeOOH).该物质在室温下稳定,有较高的硬度,其比表面积约为 300 m2/g,零电荷点 (PZC)在 pH 7～ 8之间.根据 M(o)ssbauer谱的鉴定,它具有四方纤铁矿(β-FeOOH)的结构特征. FeOOH和它与各溶质的表面配合物的 X射线光电光谱结果表明, FeOOH与 Pb、 Zn和GrO(4/2-)之间的反应是物理吸附,而与PO(4/3-)和AsO(4/3-)之间的反应是化学吸附. 3个阴离子及 2个阳离子的吸附等温式结果表明,该三价铁羟基氧化物的吸附能力比常见的铁羟基氧化物强 3倍.磷酸盐与砷酸盐之间的竞争反应结果表明,磷酸盐与 FeOOH的反应比砷酸盐强烈.     

Evaluating the effect of active ions on the early performance of soft clay solidified by modified biomass waste-rice husk ash

Acta Geotechnica - Soft clay generally cannot be directly used as subgrade material due to its poor engineering characteristics. The application of rice husk ash (RHA) for the solidification of...     

The Electrical Conductivity of Gabbro at High Temperature and High Pressure

The electric conductivity of gabbro has been measured at 1.0 - 2.0 GPa and 320-700℃, and the conduction mechanism has been analyzed in terms of the impedance spectra.Experimental results indicated that the electric conductivity depends on the frequency of alternative current. Impedance arcs representing the conduction mechanism of grain interiors are displayed in the complex impedance plane, and the mechanism is dominated at high pressure.These arcs occur over the range of 102 - k× 105 Hz (k is the positive integer from 1 to 9). On the basis of our results and previous work, it is concluded that gabbro cannot form any high conductivity layer (HCL) in the middle-lower crust.