西北低煤阶盆地生物成因煤层气成藏模拟研究

在美国粉河、澳大利亚苏拉特等低煤阶盆地煤层气勘探取得突破以前,一直认为具有商业价值的煤层气资源主要存在于中煤阶的煤层中,煤阶太低,一般含气量不高,不具有勘探价值。但是近几年来的发现证实,低煤阶盆地煤层厚度大,渗透率高,资源丰度大,含气饱和度高,同样可获得商业性气流,而且从其气体的成因来看,其中有很大一部分是生物成因的煤层气。利用煤层气成藏模拟装置对低煤阶含煤盆地的煤岩样品开展成藏模拟,从实验角度证明了中国西北地区虽然煤层煤阶较低,热成因气较少,但是却存在着具有商业价值的二次生物成因的甲烷气,再加上含煤层系众多,煤层厚度大,资源丰度极高,仍具有巨大的勘探潜力。      

连续梁的简便计算

利用三转角方程，对连续梁的内力进行精确的计算，该方法简捷明了，便于应用。     

工业建筑多层框架的活荷载不利布置

以设防烈度为8度的框架厂房为例，详细分析了活荷载不利布置对框架梁、柱内力的影响，得出何时需要考虑活荷载不利布置、何时不需要考虑活荷载不利布置的结论，可供工程设计参考。     

Use of radial forces for fault detection in tapping

A model-based method for fault detection in tapping based on torque and radial forces is proposed. The method allows the identification of faults typical of a tapping operation including axial misalignment, tap runout, tooth breakage both singly and together. The validation experiments have been run on aluminum 356 workpieces for different combinations of process faults. Results have shown that the model predictions are in good agreement with the experimental radial force and torque signals under various fault conditions.     

Evidence of High Vertical Wave-Number Behavior in a Continuously Stratified Reservoir: Boadella, Spain

High vertical wave-number modes clearly dominate the internal wave field during the stratification period in Boadella reservoir in northeast Spain. In this period, the extraction of hypolimnetic water, due to summer irrigation, brought the surface level down by 6 m in one month and the epilimnetic water progressively occupied the whole water column. The temperature profile, with the exception of a few meters at the surface layer, presented an almost constant temperature gradient of about 0.7°C/m. The period of the main vertical mode is 24 h with an amplitude of around 1 m. Thermistor chain records and meteorological data allow us to deduce that this mode is, at least, a third vertical mode forced by the wind, which normally has a typical periodicity of 24 h. However, when the wind changes direction from south to north, the circulation cells developed due to this forced nonstationary oscillation are destroyed. When this occurs, the Bulk Richardson number is Rib ～ 1. Similar vertical structures as a response to wind forcing should be expected in similar systems, although this has not been reported in the literature.     

矩形垂直筛板的流体力学性能研究

在600mm的有机玻璃冷模塔中,用水-空气体系测定矩形垂直筛板的塔板压降、漏液和雾沫夹带等流体力学性能,确定了合理的塔板结构,使其具有较高的气液通量和较宽的操作范围,空塔动能因子最大可达3.0kg1/2(m1/2.s)-1,液流强度可达21.6m3/(m.h)。并对不同气液流量下塔板的流体力学实验数据进行关联和分析,得出了矩形垂直筛板的干板压降计算关联式以及漏液率随液流强度和空塔动能因子的变化关系,为矩形垂直筛板的设计提供了依据。与新垂直筛板相比,矩形垂直筛板具有更低的塔板压降。     

Multiplicative cases from additive cases: Extension of Kolmogorov–Feller equation to parametric Poisson white noise processes

In this paper the response of nonlinear systems driven by parametric Poissonian white noise is examined.As is well known, the response sample function or the response statistics of a system driven by external white noise processes is completely defined. Starting from the system driven by external white noise processes, when an invertible nonlinear transformation is applied, the transformed system in the new state variable is driven by a parametric type excitation. So this latter artificial system may be used as a tool to find out the proper solution to solve systems driven by parametric white noises. In fact, solving this new system, being the nonlinear transformation invertible, we must pass from the solution of the artificial system (driven by parametric noise) to that of the original one (driven by external noise, that is known). Moreover, introducing this invertible nonlinear transformation into the Itô’s rule for the original system driven by external input, one can derive the Itô’s rule for systems driven by a parametric type excitation, directly. In this latter case one can see how natural is the presence of the Wong–Zakai correction term or the presence of the hierarchy of correction terms in the case of normal and Poissonian white noise, respectively. Direct transformation on the Fokker–Planck and on the Kolmogorov–Feller equation for the case of parametric input are found.     

HYDRODYNAMIC FORCE ON SMOOTH HORIZONTAL CYLINDER IN UNIFORM OSCILLATORY FLOW

ＨＹＤＲＯＤＹＮＡＭＩＣ　ＦＯＲＣＥ　ＯＮ　ＳＭＯＯＴＨ　ＨＯＲＩＺＯＮＴＡＬ　ＣＹＬＩＮＤＥＲ　ＩＮ　ＵＮＩＦＯＲＭ　ＯＳＣＩＬＬＡＴＯＲＹ　ＦＬＯＷＨＹＤＲＯＤＹＮＡＭＩＣＦＯＲＣＥＯＮＳＭＯＯＴＨＨＯＲＩＺＯＮＴＡＬＣＹＬＩＮＤＥＲＩＮＵＮＩＦ...     

文克尔地基上中面x方向受力的矩形薄板的振动

建立文克尔地基上x=0与x=a两对边受面内均布拉(压)力作用的矩形薄板自由振动和强迫振动的微分方程并求得其通解。给出振型函数的表达式，用广义函数的富里叶展开，讨论板在不同形式载荷作用下的强迫振动响应。文中导出的各种情况下的影响函数，亦可用于求解相应情况下矩形薄板的静力弯曲与稳定性问题。