Application of RLS adaptive filtering in signal de-noising

针对信号中混有噪声的问题,介绍了一种基于RLS算法的自适应信号消噪系统,并阐述了自适应滤波的原理以及RLS算法的步骤与流程。通过实例仿真,得到了基于RLS算法的自适应消噪系统仿真图。经过对比分析可知,RLS自适应滤波能较好地消除噪声,获得有用信号,从而验证了该方法的有效性和系统的合理性。     

A Numerical Gas Fracturing Model of Coupled Thermal,Flowing and Mechanical Effects

Gas fracturing, which overcomes the limitation of hydraulic fracturing, is a potential alternative technology for the development of unconventional gas and oil resources. However, the mechanical principle of gas fracturing has not been learned comprehensively when the fluid is injected into the borehole. In this paper, a damagebased model of coupled thermal-flowing-mechanical effects was adopted to illustrate the mechanical principle of gas fracturing. Numerical simulation tools Comsol Multiphysics and Matlab were integrated to simulate the coupled process during the gas fracturing. Besides, the damage evolution of drilling areas under several conditions was fully analyzed. Simulation results indicate that the maximum tensile stress, which occurs in the upper and lower of the injection hole, decreases with the increase of the tectonic stress coefficient (TSC). As the TSC increases, shear fractures increase, a crushed area is gradually formed and the seepage area increases rapidly. The influence of TSC on fracture expansion is concluded as follows: with the decrease of TSC, the relative width of fractures decreases whilst the depth increases. It indicates that thermal stress and pore pressure promote the expansion of tensile fractures but restrain the expansion of shear fractures. Therefore, a relatively lower injection gas pressure is required to obtain the same degree of fracturing with a coupled thermal gradient.     

一种基于Hadoop的大规模图直径算法

为提高具有百万个节点以上的大规模图处理效率,通过研究大规模图和分布式框架Hadoop,提出了GDH大规模图直径算法。算法通过每次计算出半径相同的图节点,直到最后一次迭代求出所有节点的半径,然后用节点半径之和除以节点数算出大规模图直径。算法的时空复杂度不大,并且与经典的直径算法相比,GDH算法的效率高些。经测试雅虎网站和脸谱网站的网页数据,发现该算法可清晰地分析Web图的网页节点和社交图的人际关系。     

整体现浇组合过梁配筋形式与力学性能研究

研究了非抗震作用下整体现浇组合过梁的配筋形式,通过本文建立的模型进行了整体现浇组合过梁配筋量的计算,利用试验验证了上述配筋形式的可行性,得到如下结论：1）过梁部分受拉区钢筋锚入连梁或框梁的锚固长度36 d（非抗震设计）满足要求,过梁部分受拉区配筋形式理论上可行;2）按照连梁或框梁部分与过梁部分分别计算的配筋量,当达到正常使用极限状态时,连梁或框梁部分受压区钢筋与过梁部分受拉区钢筋能够达到甚至超过屈服强度,而连梁或框梁部分受拉区钢筋则未达到屈服强度,将连梁部分受拉区钢筋面积减少20％左右时才能达到屈服强度;3）过梁部分受拉区钢筋面积需要增加40％左右才能保证设计的安全可靠度.     

Mechanism analysis of solvent selectivity and energy-saving optimization in vapor recompression-assisted extractive distillation for separation of binary azeotrope

Octane and p-xylene are common components in crude gasoline, so their separation process is very important in petroleum industry. The azeotrope and near azeotrope are often separated by extractive distillation in industry, which can realize the recovery and utilization of resources. In this work, the vapor–liquid equilibrium experiment was used to obtain the vapor–liquid equilibrium properties of the difficult separation system, and on this basis, the solvent extraction mechanism was studied. The mechanism of solvent separation plays a guiding role in selecting suitable solvents for industrial separation. The interaction energy, bond length and charge density distribution of p-xylene with solvent are calculated by quantum chemistry method. The quantum chemistry calculation results and experiment results showed that N-formylmorpholine is the best solvent among the alternative solvents in the work. This work provides an effective and complete solvent screening process from phase equilibrium experiments to quantum chemical calculation. An extractive distillation simulation process with N-formylmorpholine as solvent is designed to separate octane and p-xylene. In addition, the feasibility and effectiveness of the intensified vapor recompression assisted extraction distillation are also discussed. In the extractive distillation process, the vapor recompression-assisted extraction distillation process is globally optimal. Compared with basic process, the total annual cost can be reduced by 43.2%. This study provides theoretical guidance for extractive distillation separation technology and solvent selection.     

钳位型分裂Y源逆变器

Y源逆变器具有高电压增益的优点,但是其电压增益中的调制因数和直通占空比相互制约,影响其电压质量和直流母线利用率,漏感的存在也使Y源逆变器流经耦合电感的电流在状态转换过程中发生突变,导致功率开关管产生明显的电压尖峰。分裂Y源逆变器SYSI(split Y-source inverter)工作过程中由于不需要引入直通状态,可以有效解决上述问题,为此提出一种钳位型分裂Y源逆变器CSYSI(clamped split Y-source inverter),不仅可以同向调节调制因数和升压占空比,消除开关管电压尖峰,而且通过加入电压钳位单元,进一步提升了电压增益。对该逆变器进行了详细的理论分析,并进行MATLAB/Simulink仿真与样机实验,验证了其合理性。     

油气输导机制及输导体系定量评价研究

为了减少输导体系多解性和更客观、准确地对其进行评价,该文对我国各主要含油气盆地输导体系进行了系统分析与总结,提出了基于油气输导机制的输导体系分类方案,将输导要素划分为3大类:第一类为必要的输导要素(包括输导空间、输导动力和输导流体);第二类为描述输导体系重要特性的输导要素(如输导方向、输导能力);第三类为补充说明输导体系的输导要素(如输导体系的规模与层次、形成与作用时期等)。提出的基于输导机制的输导体系命名原则为:输导体系规模与层次+形成与作用时期+输导能力+输导方向+输导动力+输导空间。同时根据各输导要素对油气运聚成藏的贡献,建立了各类输导要素优劣的定量评价标准与赋值原则。总结了成藏期古输导体系恢复方法和步骤,其中古孔隙和古构造的恢复是成藏期输导格架建立的关键。这为输导体系定量评价奠定了基础,从而可以更好地根据输导体系预测潜在油气藏,提高勘探成功率。     

基于BP神经网络的矿井小构造预测

阐述了矿井小断层水平延展长度预测BP网络模型的构建、训练及模拟方法,在总结小断层落差、断层的走向、断层的倾角及断层的倾向等影响因素的基础上,结合赵官井田主采7#煤层典型样本数据,运用Matlab软件来建立网络预测模型,并对该煤层2713和2712 2个工作面的小断层水平延展长度进行预测,发现该网络模型的预测结果与实测结果更接近。     

化学工程领域全日制专业学位研究生实践能力培养的研究

实践性是全日制专业学位研究生教育的基本特点。结合本校现阶段化学工程领域全日制专业学位研究生培养中存在的问题,从专业课程教学改革与实践、发展和完善相对开放的实验体系以及提高指导教师自身素质等方面,探讨了化工类专业学位研究生实践能力培养模式的构建。     

高熵合金涂层研究进展

制备各类涂层对材料表面进行强化是提高材料服役性能的重要途径,可根据服役环境要求,在不影响基体性能的前提下,通过调控工艺改变涂层成分、组织结构,从而改善其性能,延长部件的使用寿命.高熵合金及其涂层是近年来材料领域的研究热点,具有优异的强度、韧性、耐蚀性、耐磨性等特点,在表面工程领域的应用发展迅速.通过设计不同体系的高熵合...