理论上,通过平移与旋转运动联合观测的六分量地震记录,在单物理点上即可实现浅层横波速度结构的反演.本文主要目的为结合正演模拟设计六分量面波数据处理的流程,并将此单物理点方法应用至广州市区所采集的数据当中.本次研究在正演模拟的阶段中,通过时频域滤波方法实现了基阶面波数据的提纯,设计了使用单物理点的六分量数据实现浅层横波速度结构反演的流程;在实际应用阶段,通过数据的波形和偏振分析,介绍了甲烷气爆震源激发下的六分量波场特征,并分析出基阶面波所在的时频区域,结合时频域滤波、基阶面波相速度反演得到了试验区的横波速度结构.其结果与区域地质调查结果有较好的对应性,说明此六分量地震观测方法在工程地震领域的应用是可行的.

With the development of rotational seismology, the observation of seismic rotational components deserves more attention in shallow engineering geological prospecting. In shallow seismic exploration, methane detonation source and electric spark source as new sources, and the characteristics of rotational motion under the excitation of these two vibroseises are worth studying. Based on the six-component seismic observation experiments of methane and electric spark sources in Guangzhou city and combining the experiments with numerical simulation of translational and rotational motions in a shallow 2-dimensional model, this paper proves that it’s feasible to capture the rotations induced by shallow engineering vibrations. By analyzing spectrum characteristics and particles polarization of the seismic data in different frequency bands and different frequency characteristics of these two sources, this paper compares the similarities and differences between translational and rotational components, and finds that rotational components can provide additional information different from the translational component and high frequency signals are more prominent in rotational components. Besides, river channel greatly diminishes the energy of surface waves below 10 Hz of observed data. These analyses indicate the characteristics and possible applications of surface waves in rotational components are so different from the ones in translational components.

煤炭地下气化技术是煤炭开采方式变革的前沿技术,在提高煤炭资源利用率、降低开采成本、安全环保等方面具有较大优势.本文从地质角度出发,对阿拉达布斯煤田伊和达布斯矿区应用煤炭地下气化技术的适宜性、存在的局限性及在未来开发生产过程中气化产品利用方式的选择进行了探讨.认为伊和达布斯矿区从地质角度分析采用地下气化技术开采是适宜的,虽存在一定的局限性,但只要选择合适的煤炭地下气化技术和最优的气化产品利用方式,此项技术在本矿区的采用会获得较好的经济效益.

The mechanical properties of micro- or nano-scale hydrate are of great significance to reveal the interaction between hydrate and sediment skeleton in pores under the external loads and to evaluate the macroscopic mechanical behavior of hydrate deposits in nature. In this paper, the tetrahydrofuran (THF) hydrate samples are analyzed by the atomic force microscope and the silica (SiO2) microspheres colloidal probe with a diameter of 5 μm. The relationship between the press-in depth, contact time, and contact force is obtained at the temperature in the range from −30°C to −10°C and at driving speed of 0.5–20 μm/s. The adhesion force between SiO2 microsphere and THF hydrate is also measured. The result shows that the plastic deformation of the THF hydrate occurs during the indentation, and the phase transformation induced by the indentation can further enhance this plastic behavior. At the same temperature and contact force, a greater press-in depth was observed at a lower indentation rate or higher temperature. The THF hydrate exhibited greater plasticity and lower strength. The yield stress of the THF hydrate has a threshold, which can be one of the important reasons for strain hardening and strain softening of macroscopic hydrate sediments. According to the modified power-rate rheological (PLR) viscoelastic model, the viscoelasticity of a THF hydrate is significant at a low driving rate and relatively high temperature. The adhesion force between the microsphere and THF hydrate was caused by the liquid-like layer and decomposed liquid on its surface, and it was 1.1–2.5 μN, which was closely related to the contact area before they separated.

L-System不仅可以模拟单株植物,而且可以模拟一片森林。由于森林中的树木形状不仅受内部信息的影响,还受外界多种因素影响。所以森林仿真是一个多参数的问题,遗传算法是解决多参数的问题有力工具。文章中使用遗传算法优化森林中树木的仿真。