海底管道开沟机械的技术经济性能评定与选型

本文在对水下管道开沟机械的需求市场、实际应用和研制开发动向作深入调研的基础上，选择水下管道开沟机械特有的技术先进性、适用性、安全可靠性以及经济性评价指标，构造评价模型，对水下管道施工作业中广为应用的水力冲射开沟机械、海底管道犁、机械开沟机和土壤液化法埋管设备及其机型的技术经济性能作了较为详尽地分析对比及综合评价。在此基础上，笔者提出了水下管道开沟机械的一般选型原则和对我国海底管道开沟机械研究开发工     

高速摄影对散体振动的研究

以现代高速摄影技术和图像分析以及数据处理方法，针对高效振动磨机中弹性散体工质（如钢棒、球体等）的振动力学进行了深入的探讨和分析，为研究散体动力学和振动超细粉碎过程中的能量分布和传递规律以及能量与物质的相互转换机理奠定了基础，也为相关学科的发展提供了一种可以借鉴的方法。     

A Unified Variational Principle of Fluid Mechanics and Application on Solitary Subdomain or Point

-According to basic equations of fluid mechanics, this paper presents a unified variational principle of fluid mechanics (UVPFM) by using the optimization method of weighted residuals (OMWR). The advantages are as follows, the establishment of the functional and the variational principle is easy, it can change various problems of fluid mechanics derived by basic equations into a unified optimization problem, and the solution is the optimum one in some sense. According to the OMWR for the solitary subdomain, this paper uses UVPFM onto any solitary subdomain and gives the solution of the hydrodynamics equation which is suitable only for that solitary subdomain. According to the OMWR for solitary point, this paper uses UVPFM to any solitary point and gives the solution of the hydrodynamics equation (point solution) which is suitable only for that solitary point. As the solution for the solitary subdomain or solitary point is developed independently, the compatibility with other subdomain or other points, do     

The Structure of A Turbulent Jet in A Crossflow-Effect of Jet-Crossflow Velocity

A comprehensive numerical study on the three-dimensional structure of a turbulent jet in crossflow is performed. The jet-to-crossflow velocity ratio (R) varies in the range of 2 - 16; both vertical jets and inclined jets without excess streamwise momentum are considered. The numerical results of the Standard two-equation k-ε model show that the turbulent structure can be broadly categorised according to the jet-to-crossflow velocity ratio. For strong to moderate jet discharges, i.e. R> 4, the jet is characterized by a longitudinal transition through a bent-over phase during which the jet becomes almost parallel with the main freestream, to a sectional vortex-pair flow with double concentration maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless distance of around 20-60. The similarity coefficients are only weakly dependent on R. The cross-section scalar field is kidney-shaped and bifurcated, vvith distinct double concentr     

Tectonics of a fast spreading center: A Deep-Tow and sea beam survey on the East Pacific rise at 19°30′ S

Sea Beam and Deep-Tow were used in a tectonic investigation of the fast-spreading (151 mm yr^-1) East Pacific Rise (EPR) at 19°30 S. Detailed surveys were conducted at the EPR axis and at the Brunhes/Matuyama magnetic reversal boundary, while four long traverses (the longest 96 km) surveyed the rise flanks. Faulting accounts for the vast majority of the relief. Both inward and outward facing fault scarps appear in almost equal numbers, and they form the horsts and grabens which compose the abyssal hills. This mechanism for abyssal hill formation differs from that observed at slow and intermediate spreading rates where abyssal hills are formed by back-tilted inward facing normal faults or by volcanic bow-forms. At 19°30 S, systematic back tilting of fault blocks is not observed, and volcanic constructional relief is a short wavelength signal (less than a few hundred meters) superimposed upon the dominant faulted structure (wavelength 2–8 km). Active faulting is confined to within approximately 5–8 km of the rise axis. In terms of frequency, more faulting occurs at fast spreading rates than at slow. The half extension rate due to faulting is 4.1 mm yr^-1 at 19°30 S versus 1.6 mm yr^-1 in the FAMOUS area on the Mid-Atlantic Ridge (MAR). Both spreading and horizontal extension are asymmetric at 19°30 S, and both are greater on the east flank of the rise axis. The fault density observed at 19°30 S is not constant, and zones with very high fault density follow zones with very little faulting. Three mechanisms are proposed which might account for these observations. In the first, faults are buried episodically by massive eruptions which flow more than 5–8 km from the spreading axis, beyond the outer boundary of the active fault zone. This is the least favored mechanism as there is no evidence that lavas which flow that far off axis are sufficiently thick to bury 50–150 m high fault scarps. In the second mechanism, the rate of faulting is reduced during major episodes of volcanism due to changes in the near axis thermal structure associated with swelling of the axial magma chamber. Thus the variation in fault spacing is caused by alternate episodes of faulting and volcanism. In the third mechanism, the rate of faulting may be constant (down to a time scale of decades), but the locus of faulting shifts relative to the axis. A master fault forms near the axis and takes up most of the strain release until the fault or fault set is transported into lithosphere which is sufficiently thick so that the faults become locked. At this point, the locus of faulting shifts to the thinnest, weakest lithosphere near the axis, and the cycle repeats.     

膏溶角砾岩侧限膨胀特性试验研究

研究了膏溶角砾岩的侧限膨胀特性及其影响因素。这种岩石受到扰动后可吸水发生膨胀变形使其结构发生变形甚至破坏。通过GDG高压固结仪采用平衡加压法和充分膨胀法研究了侧限情况下岩石的膨胀力指标, 解释了充分膨胀法膨胀力指标大于平衡加压法膨胀力指标的原因。通过试验研究了供水充足条件下膏溶角砾岩侧限自由膨胀变形演化规律, 阐述了膏溶角砾岩侧限膨胀变形的影响因素。岩石试样采自山西石太客运专线太行山隧道, 试验结果表明, 膏溶角砾岩的膨胀特性不同于常规的膨胀岩, 其轴向膨胀变形随含水率增加而增加, 随密度增大而减小。     

Numerical simulation of migration–accumulation of oil resources

Numerical simulation of oil migration and accumulation is to describe the history of oil migration and accumulation in basin evolution. It is of great value to the evaluation of oil resources and to the determination of the location and amount of oil deposits. This thesis discusses the characteristics of petroleum geology and permeation fluid mechanics. For the three-dimensional problems of Dongying hollow of Shengli Petroleum Oil Field, it puts forward a new model and a kind of modified method of upwind finite difference fractional steps implicit interactive scheme. For the famous hydraulic experiment of secondary migration–accumulation, the numerical simulation test has been done, and both the computational and experimental results are basically identical. For the actual problem of Dongying hollow, the numerical simulation test and the actual conditions are basically coincident. Thus, the well-known problem has been solved.     

Experimental investigation of the elastic modulus of a fractal system—A model of fractured rocks

The elastic properties of a physical model representing a damaged rock matrix were studied using a square lattice deformed under tensile stress. The elastic modulusM of such a system varies in agreement with percolation theory as|x–x _c | ^f , wherex is the damage parameter andx _c the threshold value of the damage parameter,f3.6. Atxx _c the scale dependence ofM can be expressed asML ^–f/v , whereL is the size of the sample andv the correlation exponent in percolation theory.The experimental results are of interest in assessing elastic properties in earthquake focal zones and fault zones in general.     

中国三个大地震的震源参数及讨论

大地震的震源机制及地震矩、应力降等参数,不(又对认识地震的破裂过程,而且对预报强地面运动都是非常重要的。一些文章对板内地震应力降的特点、地震矩与高频源谱的关系及区域特征的讨论,使我们可直接由长周期体波或面波得出的地震矩M₀估计出不同地区中大地震的高频源谱,以供强地面运动预报参考。 由于对发生在中国板内的1976年11月6日盐源地震（M_s=6.5）和1976年11月15日宁河地震（M_s=6.3）的震源参数还没有详尽的报道;另外,对1973年7月14日     

Seismic activity associated with the subducting motion of the Philippine Sea plate beneath the Kanto district, Japan

The Pacific plate and the Philippine Sea plate overlap and subduct underneath the Kanto region, central Japan, causing complex seismic activities in the upper mantle. In this research, we used a map selection tool with a graphic display to create a data set for earthquakes caused by the subducting motion of the Philippine Sea plate that are easily determined. As a result, we determined that there are at least four earthquake groups present in the upper mantle above the Pacific plate. Major seismic activity (Group 1) has been observed throughout the Kanto region and is considered to originate in the uppermost part of mantle in the subducted Philippine Sea plate, judging from the formation of the focal region and comparison with the 3D structure of seismic velocity. The focal mechanism of these earthquakes is characterized by the down-dip compression. A second earthquake layer characterized by down-dip extension (Group 2), below the earthquakes in this group, is also noted. The focal region for those earthquakes is considered to be located at the lower part of the slab mantle, and the Pacific plate located directly below is considered to influence the activity. Earthquakes located at the shallowest part (Group 3) form a few clusters distributed directly above the Group 1 focal region. Judging from the characteristics of later phases in these earthquakes and comparing against the 3D structure of seismic velocity, the focal regions for the earthquakes are considered to be located near the upper surface of the slab. Another earthquake group (Group 4) originates further below Group 2; it is difficult to consider these earthquakes within a single slab. The seismic activities representing the upper area of the Philippine Sea plate are Group 3. This paper proposes a slab geometry model that is substantially different from conventional models by strictly differentiating the groups.