多种采动影响区杆塔地基稳定性数值分析

煤炭开采中多种采动影响区包括老采空区、现采空区和未来采空区(规划区)等几种类型。本文对晋东南至南阳段1000kV特高压输电线路途经山西煤田采空区和规划区,评价规划区煤层开采对已建输电杆塔地基稳定性的影响,根据现场收集的资料,利用FLAC3D 数值方法对特高压线路N177输电杆塔下部3号煤层进行开采模拟,并在3号煤层已经开采条件下,进行9号煤层复采的数值模拟。结果表明, 9号煤层复采将对输电杆塔地基稳定性造成影响,地表最大沉降为1.15m,输电杆塔基础沿线最大倾斜为5.7,开采过程中如杆塔基础不采取抗变形措施,杆塔基础倾斜将会危及到特高压输电线路的稳定。     

双相横向各向同性介质分界面上弹性波反射与透射问题研究

从双相横向各向同性介质弹性波波动方程出发 ,利用边界上的 4个连续性条件 ,计算双相横向各向同性介质分界面上弹性波反射和透射系数 .计算表明 ,快纵波在双相横向各向同性介质分界面上 ,要产生反射快纵波、反射转换 qSV波、反射转换慢纵波和透射快纵波、透射转换qSV波、透射转换慢纵波 .反射转换慢纵波振幅和透射转换慢纵波振幅均较小 .频率、耗散和各向异性大小影响着快纵波反射系数的大小 .     

我国铁路水害及其评估模型研究

文章分析了我国铁路水害的特点,并用1980~1995年的断道时间和次数与同期的大雨、暴雨日数,分别建立了全国和成都、郑州、哈尔滨、沈阳4个铁路局的铁路水害统计模型,为定量评估气候异常对铁路交通的影响奠定了基础。     

1974年10月11日白光耀斑的光谱分析

１９７４年１０月１１日耀斑的光谱分析表明，连续发射和微波爆发几乎同时达到极大。在连续辐射极大时刻出现了高项巴耳末发射线和微弱的巴耳末跳跃，所有这些说明这个耀斑是Ｉ型白光耀斑。我们发现，在这个耀斑连续发射的极大时刻，ＣａＩＩＫ线的Ｋ１处强度大大增强，约达到连续辐射强度的一半，对应的辐射温度达到５７１６Ｋ。这个反常增强的持续时间小于４分钟。现有的半经验模型似不能给出这样的结果。色球压缩区也不能给出解释     

在磁场条件下恒星大气Stokes轮廓特征量的研究

本文根据偏振辐射转移方程组就形成于有磁场的恒星大气中的Stokes轮廓的一些特征量与磁场强度大小的关系从理论上进行了探讨。结果表明:在强场情形下,L,Q,U,V的绝对值在非常靠近Zeeman分裂量±Δλ_H处达到极大;Hale的测量方法给出了总的场强的很好量度。最后用合成轮廓作出了相应的检验。     

Microbial remains in some earliest Earth rocks: Comparison with a potential modern analogue

Carbonaceous matter (CM) from ca. 3.5 Ga hydrothermal black cherts of the Pilbara Craton of Western Australia and the Barberton Greenstone Belt of South Africa yielded transmission electron microscopy (TEM) images that are suggestive of microbial remains and possible remnants of microbial cell walls. These are compared to a potential modern analogue, the hyperthermophilic Methanocaldococcus jannaschii, derived from an active seafloor hydrothermal environment and cultured under similar conditions. A striking resemblance to the early Archaean forms was evident in wall structure and thermal degradation mode. Cell disintegration of the cultures occurred at 100 °C marking the limits of life. Complete disintegration, deformation and shrinkage occurred at 132 °C. A multidisciplinary approach to the characterisation of the CM was undertaken using organic petrology, TEM coupled with electron dispersive spectral analysis (EDS), high resolution TEM (HRTEM) to determine molecular ordering, and elemental and carbon isotope geochemistry. Reflectance measurements of the CM to determine thermal stress yielded a range of values corresponding to several populations, and pointing to different sources and processes. The δ¹³C values of Dresser Formation CM (−36.5 to −32.1‰) are negatively correlated with TOC (0.13–0.75%) and positively correlated with C/N ratio (134–569), which is interpreted to reflect the relative abundance of high R_o/oxidised/recycled CM and preferential loss of ¹²C and N during thermal maturation. TEM observations, inferred carbon isotopic heterogeneity and isotope fractionations of −27 to −32‰ are consistent with the activity of chemosynthetic microbes in a seafloor hydrothermal system where rapid silicification at relatively low temperature preserved the CM.     

Extrinsic and intrinsic mode of hydrogen occurrence in natural olivines: FTIR and TEM investigation

Olivine crystals from two mantle nodules in kimberlites (pipe Udachnaya and pipe Obnazennaya, Yakutiya, Siberia) were investigated using EMP, TEM, AEM and FTIR techniques to determine the mode of hydrogen occurrence in olivine. Olivine contains three types of nanometer-sized inclusions: “large” inclusions of hexagonal-like shape up to several hundred nm in size (1), lamellar defects (2) and small inclusions of hexagon-like shape up to several 10?nm in size (3). Lamellar defects and small inclusions are considered to be a “hydrous” olivine. All three types of inclusions contain OH^? or water, but they are different with respect to their phase composition. In “large” inclusions (1) hydrous magnesium silicates, such as serpentine?+?talc (“kerolite”?) and 10-Å phase?+?talc were identified. Lamellar defects (2) and small inclusions (3) are depleted in Mg and Fe compared to the olivine matrix, while the silica content is the same as that of olivine. Modulations in the periodicity of the olivine structure are observed in SAED patterns and HREM images of (2) and (3). The superperiodicity can be referred to OH^?-bearing point defect ordering in the olivine structure. If this is the case, the material of both lamellar defects and small inclusions can be assumed to be a “hydrous olivine” Mg_{2– x} v _x SiO₄H_{2 x} with a cation-deficient olivine crystal structure. Thus, both an extrinsic mode of hydrogen occurrence in olivine, such as nanometer-sized inclusions of OH^?-bearing magnesium silicates, and an intrinsic mode of hydrogen incorporation into the olivine structure, such as “hydrous olivine” in itself, were found. The data obtained here show that the OH absorption bands observed in olivine spectra at 3704(3717) and 3683(3688) cm^?1 can be unambiguously identified with serpentine; the band at 3677(3676) cm^?1 can be associated with talc. The absorption bands observed at 3591 and 3660?cm^?1 in olivine match those of the 10-Å phase at 3594, 3662 and 3666?cm^?1.     

The late-and post-Variscan tectonic evolution of the Western Border fault zone of the Bohemian massif (WBZ)

 Paleostress analysis and evaluation of the stratigraphic unconformities reveal an extremely polyphase development of one of the most prominent fault zones of Central Europe, usually known as the Franconian Line (FL). Because the FL is just one fault zone, although it is the most important fault zone within a complex fault system, a more appropriate term is used herein: Western Border fault zone of the Bohemian massif (WBZ). The reconstruction of the paleostress history was carried out by analysing sequences of individual strain increments that belong to the same stratigraphic “units” (e.g., late-Variscan granites, Tertiary basalts). A succession of at least 15 paleostress directions and tectonic regimes have been determined since late-Variscan time. Received: 7 July 1996 / Accepted: 24 October 1996     

Development of composite planar fabric in mylonites along the Median Tectonic Line, southwest Japan

Abstract Mylonites along the Median Tectonic Line, southwest Japan commonly contain shear bands comprising S(-C)-Ss fabrics. This paper stresses the lithologic control on the orientation, dimension and development of shear bands by comparing the microstructure of the shear bands in different rock types (P mylonites, F mylonites, micaceous phyllonite and quartzose phyllonite). There is no significant change of the α angles (average 21–24°) between Ss and S toward the centre of the shear zone (viz. increasing the intensity of mylonitization) and it is different from the S-C relationship in a narrow sense.
The generation of the composite planar fabric can be classified into four different strain partitioning models: S only type without any slip surface (model A); S-C type (model B); S-Ss type with Ss-slip precedence (model C), and S-Ss type with S-slip precedence (model D). Model C is proposed in this paper and is similar to the model for the generation of Riedel shears in brittle shear zones. An unstable slip between porphyroclasts and the matrix during ductile flow can easily initiate shear bands. Formation of a composite planar fabric is initiated according to model A, followed by model C in conditions of increasing strain, and then model D when the angle between S and the shear zone boundary becomes small enough (α/2 = 10°) to produce S-slip. Thus the generation of the shear bands probably begins in the early stages of shear deformation and continues until the latest stages.     

Experimental study on the performance of the multiple-layer breakwater

Based on the idea of disturbing the water motion in the upright direction, a new kind of multiple-layer breakwater is proposed in this article, which mainly consists of several horizontal plates. The breakwater's performance of dissipating waves has been investigated in detail in the regular wave tests. The factors identified with the characteristics of the breakwater are discussed, such as the relative width, the wave steepness and the models geometrical parameters (the width and the gap). The comparison and analysis of the transmission and reflection coefficients with respect to different factors are presented. The model test results indicate that the multiple-layer breakwater has the good characteristic of dissipating waves. Further more, only in a little extent can it reflect the waves. The multiple-layer breakwater proposed in the paper is very significative to promote the open type breakwater to be the permanent wave attenuator in the application.