任意阵列形状的欠定多目标方位估计

随着人类社会对海洋认识和探索的深入,对水下监测和探测设备提出了更高的要求,探测阵列模型和阵列信号处理算法决定了监测和探测设备的复杂度。 针对特定水下多目标定位平台的复杂环境,建立了一种任意空间阵列数学模型,介绍了四阶累积量算法,分析了阵列信号处理中四阶累积量的阵列扩展特性。 基于四阶累积量的 MUSIC 算法的空间谱分析,建立了任意阵列形状的欠自由度多目标方位估计的理论基础。 计算机仿真结果表明了算法的正确性和有效性。     

汪家寨煤矿煤与瓦斯突出规律及其主控因素分析

汪家寨煤矿是严重的煤与瓦斯突出矿井,依据矿区实际瓦斯地质资料,运用瓦斯地质理论和构造演化理论,研究了区域和井田构造控制特征。分析认为该矿主要以中小型突出、倾出为主,压出为辅;随煤层埋深的增加突出强度增大;C409煤突出最为严重;突出多发生在煤巷掘进面及断层影响带。分析了埋藏深度、顶底板岩性、煤厚及其变化、软分层、地质构造等因素对煤矿煤与瓦斯突出的影响,认为断层及其影响带、厚煤尤其是其增厚部位是煤与瓦斯突出的易发区域,因此断层构造和煤层厚度及其变化控制着该矿突出的发生和分布规律,为煤与瓦斯突出的主控因素。研究成果为矿井突出防治工作提供了理论指导。     

Field study on the behavior of pre-bored grouted planted pile with enlarged grout base

This paper presents the results of field tests performed to investigate the compressive bearing capacity of pre-bored grouted planted (PGP) pile with enlarged grout base focusing on its base bearing capacity. The bi-directional O-cell load test was conducted to evaluate the behavior of full scale PGP piles. The test results show that the pile head displacements needed to fully mobilize the shaft resistance were 5.9% and 6.4% D (D is pile diameter), respectively, of two test piles, owing to the large elastic shortening of pile shaft. Furthermore, the results demonstrated that the PHC nodular pile base and grout body at the enlarged base could act as a unit in the loading process, and the enlarged grout base could effectively promote the base bearing capacity of PGP pile through increasing the base area. The normalized base resistances (unit base resistance/average cone base resistance) of two test piles were 0.17 and 0.19, respectively, when the base displacement reached 5% D_b (D_b is pile base diameter). The permeation of grout into the silty sand layer under pile base increased the elastic modulus of silty sand, which could help to decrease pile head displacement under working load.

     

基于客观分析的多源卫星叶绿素a浓度产品融合方法研究

本文基于Aqua/MODIS、Terra/MODIS和Envisat/MERIS多源卫星叶绿素a浓度产品,研究了客观分析融合方法,制作了西北太平洋海域(0°~50°N,100°~150°E)叶绿素a浓度融合产品,并从有效数据空间覆盖率和产品精度两个方面对融合方法进行了评价。与单传感器以及欧洲太空局发布的GSM模型业务化融合产品相比,客观分析融合产品空间覆盖率明显提高;与收集的2002-2012年间叶绿素a浓度实测数据比较,GSM模型业务化融合产品的匹配数据点为578个,偏差为-0.20 mg/m3,均方根误差为0.37 mg/m3,客观分析法融合产品的匹配数据点为1432个,偏差为-0.21 mg/m3,均方根误差为0.36 mg/m3。结果表明:本文研究的客观分析融合方法在保证融合产品精度的同时可显著提高产品的空间覆盖率,在海洋水色融合应用前景广阔。     

SIMS U-Pb dating of micro-zircons in the lunar meteorites Dhofar 1528 and Dhofar 1627

About half of the lunar meteorites in our collections are feldspathic breccias. Acquiring geochronologic information from these breccias is challenging due to their low radioactive-element contents and their often polymict nature. We used high-spatial-resolution (5 μm) NanoSIMS (nanoscale secondary ion mass spectrometry) U-Pb dating technique to date micro-zircons in the lunar feldspathic meteorites Dhofar 1528 and Dhofar 1627. Three NanoSIMS dating spots of two zircon grains from Dhofar 1528 show a discordia with an upper intercept at 4354 ± 76 Ma and a lower intercept at 332 ± 1407 Ma (2σ, MSWD = 0.01, p = 0.91). Three spots of two zircon grains in Dhofar 1627 define a discordia with an upper intercept at 3948 ± 30 Ma and a lower intercept at 691 ± 831 Ma (2σ, MSWD = 0.40, p = 0.53). Both samples likely experienced shock metamorphism caused by impacts. Based on the clastic nature, lack of recrystallization and the consistent U-Pb and Pb-Pb dates of the zircons in Dhofar 1528, the U-Pb date of 4354 Ma is interpreted as the crystallization age of its Mg-suite igneous precursor. Some of the Dhofar 1627 zircons show poikilitic texture, a crystallization from the matrix impact melt, so the U-Pb date of 3948 Ma corresponds to an impact event, likely the Imbrium basin-forming event. These data are the first radiometric ages for these two meteorites and demonstrate that in situ (high spatial resolution) U-Pb dating has potential for extracting geochronological information about igneous activities and impact events from lunar feldspathic and polymict breccias.     

Trace elements and stable isotopic geochemistry of an Early Cambrian chert-phosphorite unit from the lower Yurtus Formation of the Sugetbrak section in the Tarim Basin

A chert-phosphorite unit from the Sugetbrak section in the Tarim Basin was analyzed for rare earth elements (Ce, Eu), redox sensitive proxies, and carbon isotopic compositions (δ¹³C_carb and δ ¹³C_org) in the lower Yurtus Formation of the Early Cambrian period. Redox sensitive element ratios (Th/U, V/Cr, Ni/Co, and V/Sc) were employed to determine the palaeoenvironmental conditions during this period. The ratios indicated that the depositional environment of the chert-phosphorite-black shale unit ranged from suboxic to anoxic. Negative Ce and positive Eu anomalies in the chert-phosphorite assemblages of the studied Yurtus Formation indicated the existence of a redox-stratified ocean, similar to that of South China. Overturn or upward expansion of the deep water-mass probably reached the shallow marine zone after the formation of the Yurtus phosphorites. The characteristics of the negative Ce anomaly may be due to phosphoritic inheritance from the Ce-depleted signature of the overlying water column. Subsequent hydrothermal inputs and reduced detrital supplies of the deep water caused by the upwelling affected certain redox sensitive elements in the sedimentary basin. δ ¹³C_carb and δ¹³C_org negative excursions in the Yurtus chert-phosphorite unit may be related to a transgression phase when episodic basinal upwelling moved ¹²C- and P-rich waters from the pelagic basin floor to the continental shelf. Although carbon isotopic compositions in the Yurtus chert-phosphorite assemblages may have suffered from diagenetic alteration, they can be used to probe diagenetic conditions. Multi-proxy geochemical studies indicated that the δ ¹³C_carb values of the Yurtus chert-phosphorite assemblages might be considered reflections of a predominantly suboxic environment that was subsequently affected by hydrothermal inputs due to the upwelling.     

鲁23井“动水位”观测的分析

本文介绍了鲁23井“动水位”观测情况。提出了一个分析有泄流的“动水位”的新方法,即把流量换算成水位,以等效静水位来表示“动水位”与流量。由于把“动水位”与流量用一个量来计算,从而为“动水位”观测定量的、统一的分析研究提供了新的方法。这对提高“动水位”井的监测预报地震能力起一定的作用。 本文还以鲁23井“动水位”观测资料为例,利用新方法进行处理的观测分析结果与理论研究结果是一致的。     

运城市水资源开发利用现状及保护对策

本文以运城市基础工作为起点,分析了地下水超采引起的一系列问题,提出了加强地下水资源保护的对策和措施.     

内蒙古北山地区阿民乌素公婆泉组变质火山岩年代学、地球化学特征及地质意义

内蒙古北山地区阿民乌素一带公婆泉组变质火山岩主要由钠长阳起岩、斜长阳起岩和斜长阳起片岩组成.三者主量元素显示相对高钠w(Na2O)=0.32％～2.46％,低钾w(K2O)=0.08％～0.38％、钛w(TiO2)=0.93％～1.03％,略富镁 w(MgO)=9.61％～12.04％、钙 w(CaO)=9.96％～1...