初级分段不连续型直线电机定位力分析与参数优化

以一种应用于环形线运输系统的初级分段不连续型直线电机为研究对象。分段不连续型初级结构的优势在于节约成本、减小损耗且电机系统更具柔性化,但此结构导致动子在段间切换受到很大端部力,造成电机运行时推力波动较大。针对该问题,提出了一种次级辅助极与初级端齿相结合的优化方案。分析电机在空载运行时所受的定位力并进行解析,对比动子在初次级耦合以及段间切换这两种情况下所受的定位力。首先对电机的主要结构参数进行优化,结合响应面法建立多目标响应面模型;然后通过遗传算法进行寻优,通过仿真对优化前后的定位力进行对比;最后基于实体样机进行测试验证,结果表明添加辅助结构下的电机模型可有效抑制定位力与推力波动。

基于二值不连续型39条码的机房管理系统设计

针对学生上机低效繁琐的人工登记方式，设计一种基于条码输入模式的机房登记管理系统。利用二值不连续型３９条码的特点以及数据库与其它高级语言之间的信息交换，实现了条码图形的打印，通过上机试运行证明该系统具有良好的运行性能。

油气藏形成与分布:从连续到不连续——兼论油气藏概念及分类

根据对常规与非常规油气藏成藏特征的综合研究,探讨了油气藏的概念、分类及其形成和分布的基本规律。重新厘定的油气藏概念为:储层中连续的油气聚集,具有独立或统一的压力系统。按照油气藏的聚集方式或分布样式将其划分为连续型、准连续型和不连续型油气聚集,认为含油气盆地中油气藏的形成往往是一个由连续到不连续的过程,在此过程中形成了以上3种类型的油气聚集。1连续型聚集:形成于烃源岩内,典型代表为页岩油气藏和煤层气藏。其主要特点是:储层致密—超致密,渗透率在纳达西—毫达西之间;油气呈游离态、吸附态、溶解态等多相态形式存在;一个连续型聚集实际上仅由一个油气藏构成,其油气在有效烃源岩分布范围内广泛而连续分布,缺乏明确边界,不存在边水和底水;油气主要是原位或就近聚集成藏,无需经过显著运移;油气聚集基本不受圈闭控制。2准连续型聚集:主要形成于邻近烃源岩的致密储层中,大多数致密油气藏属于此类。其特点是:油气呈大面积准连续分布,一个准连续聚集由多个彼此相邻的中小型油气藏组成;油气聚集缺乏明确边界,边、底水无或仅局部分布,无区域性油气水倒置;油气为大面积弥漫式充注,初次运移直接成藏或短距离二次运移成藏;油气运移聚集主要为非浮力驱动,非达西流运移;油气聚集基本不受背斜圈闭控制,而主要受非背斜圈闭特别是岩性圈闭控制。3不连续型聚集:又称为常规圈闭型油气聚集,主要形成于常规储层中,少数致密油气藏、煤层气藏甚至页岩油气藏亦属此类。其特点是:油气藏呈孤立分散不连续分布;油气藏边界明确,通常具有完整边、底水;油气藏形成一般需要经过二次运移,浮力是油气运移成藏的主要动力;油气藏形成严格受包括构造圈闭在内的各种圈闭控制。在含油气盆地中,上述3种油气聚集可同时存在,且往往形成于一个共同的烃源灶,其相互之间存在着密切联系,并具有各自独特的分布规律。因此,在油气勘探中,应当将三者作为一个统一体进行通盘考虑和研究,从而最大限度地提高勘探成效。

有不连续项的微分方程的左定谱问题

主要研究如下不连续型微分方程的左定谱问题：{-（py＇）＇（t）＋（qy）（t）=λ（ωy）（t,t≠）θ,Y（θ^＋）=（E＋K）Y（θ^-）,AY（a）＋BY（b）=0.通过对不连续点处的条件和边界条件的分析来构造合适的Hilbert空间，从而得到自伴算子的一些谱性质．

论致密大油气田成藏模式

根据对国内外致密油气聚集成藏特征的分析,提出致密大油气田存在3种成藏模式,即连续型(深盆气型)、准连续型和不连续型(常规圈闭型)。与连续型油气藏相似,准连续型油气聚集也表现为:油气分布面积较大,无明确边界,也无边底水;源、储邻近,广覆式分布;油气运移主要为非浮力驱动,运移动力主要为异常压力、扩散作用力和毛细管压力,浮力作用受限;运移的方式主要为非达西流,以涌流和扩散流为主。所不同的是:准连续型油气聚集由多个彼此相邻的中小型油气藏组成,油气呈准连续分布;油、气、水分布比较复杂,无显著油、气、水倒置;油气充注以大面积弥漫式垂向排驱为主,初次运移直接成藏或短距离二次运移成藏;储层先致密后成藏或边致密边成藏,且非均质性较强;圈闭对油气聚集成藏具有一定控制作用。研究认为,以深盆气或盆地中心气为代表的连续型油气藏与典型的不连续型常规圈闭油气藏,分别代表了复杂地质环境中致密油气藏形成序列中的两种端元类型,二者之间应存在不同的过渡类型。准连续型油气藏就是这样一种过渡类型的致密油气聚集,并且可能是致密储层中大油气田形成的主要方式。事实上,典型的连续型油气聚集应是那些形成于烃源岩内的油气聚集(如页岩气和煤层气),典型的不连续型油气聚集则是那些形成于烃源岩外近源-远源的常规储层中、受常规圈闭严格控制并且具有边底水的油气聚集;而形成于烃源岩外并且近源的致密油气藏则主要为准连续型油气聚集,其次为非典型的不连续型(常规圈闭型)油气聚集,而像盆地中心气或深盆气那样的连续型聚集则较为少见。

有源功率因数补偿

讨论功率因数补偿常用的方法、特点及实现方法。

基于碎点法的动态断裂分析

工程中的冲击防护结构在撞击、爆炸等冲击载荷下可能发生动态断裂并最终破坏,抑制结构的动态断裂是提升结构防护能力的重要手段,为此需要准确预测结构在动态载荷下的断裂行为.数值仿真是预测动态断裂的重要手段,然而当前工程中常用的有限元法在模拟断裂方面仍存在网格畸变和难以显式引入裂纹等问题.碎点法是近年来提出的一种不连续型伽辽金弱形式无网格方法,适合模拟断裂问题,本文提出一种显式动力学格式的碎点法并将该方法应用于动态断裂分析.一方面,碎点法参考弱形式无网格类方法,将求解域离散为空间中的节点和子域,并基于支持域内的节点群构造子域的位移试函数,因此该方法的子域具有抵抗畸变的能力.另一方面,碎点法参考间断伽辽金有限元法,使用分片连续的位移试函数,并引入内部界面数值通量修正保证方法的一致性和稳定性,因此该方法易于在结构中显式引入裂纹.本文首先介绍碎点法的核心思想和离散形式,接着推导了动力学碎点法弱形式动量方程,然后建立了碎点法的显式动力学求解格式,最后通过算例验证动力学碎点法预测应力波传播和动态断裂行为的能力.

Design and Realization of CPW Circuits Using EC-ANN Models for CPW Discontinuities

Novel accurate and efficient equivalent circuit trained artificial neural-network （EC-ANN） models,which inherit and improve upon EC model and EM-ANN models＇ advantages,are developed for coplanar waveguide （CPW） discontinuities. Modeled discontinuities include ： CPW step, interdigital capacitor, symmetric cross junction, and spiral inductor, for which validation tests are performed. These models allow for circuit design, simulation, and optimization within a CAD simulator. Design and realization of a coplanar lumped element band pass filter on GaAs using the developed CPW EC-ANN models are demonstrated.

Some Challenges of Deep Mining

An increased global supply of minerals is essential to meet the needs and expectations of a rapidly rising world population. This implies extraction from greater depths. Autonomous mining systems, developed through sustained R＆D by equipment suppliers, reduce miner exposure to hostile work environments and increase safety. This places increased focus on ＂ground control＂ and on rock mechanics to define the depth to which minerals may be extracted economically. Although significant efforts have been made since the end of World War II to apply mechanics to mine design, there have been both technological and organizational obstacles. Rock in situ is a more complex engineering material than is typically encountered in most other engineering disciplines. Mining engineering has relied heavily on empirical procedures in design for thousands of years. These are no longer adequate to address the challenges of the 21st century, as mines venture to increasingly greater depths. The development of the synthetic rock mass （SRM） in 2008 provides researchers with the ability to analyze the deformational behavior of rock masses that are anisotropic and discontinuous-attributes that were described as the defining characteristics of in situ rock by Leopold Mfiller, the president and founder of the International Society for Rock Mechanics （ISRM）, in 1966. Recent developments in the numerical modeling of large-scale mining operations （e.g., caving） using the SRM reveal unanticipated deformational behavior of the rock. The application of massive parallelization and cloud computational techniques offers major opportunities： for example, to assess uncertainties in numerical predictions： to establish the mechanics basis for the empirical rules now used in rock engineering and their validity for the prediction of rock mass behavior beyond current experience： and to use the discrete element method （DEM） in the optimization of deep mine design. For the first time, mining-and rock engineering-will have its own mechanics-based Ulaboratory.＂ This promises to be a major tool in future planning for effective mining at depth. The paper concludes with a discussion of an opportunity to demonstrate the application of DEM and SRM procedures as a laboratory, by back-analysis of mining methods used over the 80-year history of the Mount Lvell Copper Mine in Tasmania.

A discontinuous dynamic recrystallization model incorporating characteristics of initial microstructure

In order to describe and predict the kinetic process of discontinuous dynamic recrystallization （DDRX） during hot workingfor metals with low to medium stacking fault energies quantitatively, a new physically-based model was proposed by considering thecharacteristics of grain size distribution, capillary effect of initial grain boundaries （GBs） and continuous consumption of GBs. UsingIncoloy 028 alloy as a model system, experiments aiming to provide kinetic data （e.g., the size and volume fraction of recrystallizedgrain） and the associated microstructure were performed. Good agreement is obtained between model predictions and experimentalresults, regarding flow stress, recrystallized fraction and grain size evolution. On this basis, a thermo-kinetic relationship upon thegrowth of recrystallized grain was elucidated, i.e., with increasing thermodynamic driving force, the activation energy barrierdecreases.

Three-roller continuous setting round process for longitudinally submerged arc welding pipes

In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process can be divided into three stages:loading stage,roll bending stage and unloading stage.Based on the discretization idea,the mechanical model of the primary statically indeterminate problem of the longitudinally submerged arc welding pipes at the roll bending stage was established,and the deformation response was obtained.The simulation and theoretical results show that there are three positive bending regions and three reverse bending regions along the circumference of the pipe.The loading force of each roller shows growth,stability and downward trend with time.The error between the theoretical fitting curve and the simulated data point is very small,and the simulation results verify the reliability of the theoretical calculation.The experimental results show that the residual ovality decreases with the increase of the reduction,and the reduction of the turning point is the optimum reduction.In addition,the residual ovality of the pipe is less than 0.7%without cross-section distortion,which verifies the feasibility of this process.

The Roughness of Model Function to the Basis Functions

The roughness of the model function f（x） to the basis functions has been identified. When the model function is continuous segment, its roughness does not depend on the behavior of the first segment, but depends on ＂h＂, the shift in the slope of two consecutive segments. If the distribution of design is uniform, f（x） is continuous segment function, and h is constant, then the maximum roughness is h2/192 obtained at the midpoint of the observations. Suppose that we have a sequence of designs {Pn（x）} then its corresponding distribution {Fn （x）} converges weakly to some distribution F（x）. Let D（f） be a set of discontinuous points off（x）, it is possible to take the limit of the roughness if D（f） has zero （dF）-measure. The behavior of maximum roughness of the discontinuous segment function has been studied by using grid points.

An effective genetic algorithm to VDA with discontinuous “on-off” switches

With more and more improvements of atmosphere or ocean models,a growing number of physical processes in the form of parameterization are incorporated into the models,which,on the one hand,makes the models capable of describing the at-mospheric or oceanic movement more precisely,and on the other hand,introduces non-smoothness in the form of "on-off" switches into the models."On-off" switches enhance the nonlinearity of the models and finally result in the loss of the effec-tiveness of variational data assimilation(VDA) based on the conventional adjoint method(ADJ).This study,in virtue of the optimization ability of a genetic algorithm(GA) for non-smooth problems,presents a new GA(referred to as GA NEW) to solve the problems of the VDA with discontinuous "on-off" processes.In the GA-NEW,adaptive selection and mutation oper-ators,blend crossover operator,and elitist strategy are combined in application.In order to verify the effectiveness and feasi-bility of the GA NEW in VDA,an idealized model of partial differential equation with discontinuous "on-off" switches in the forcing term is adopted as the governing equation.By comparison with the ADJ,it is shown that the GA NEW in VDA is more effective and can yield better assimilation retrievals.In addition,VDA experiments demonstrate that the performance of a GA is greatly related to the configuration of genetic operators(selection,crossover and mutation operators) and much better results may be attained with more proper genetic operations.Furthermore,the robustness of the GA NEW to observational noise,model errors and observation density is investigated,and the results show that the GA NEW has stronger robustness than the ADJ with respect to all the three observation noises,model errors,and sparse observation.

Numerical modeling of simultaneous hydraulic fracturing in the mode of multi-well pads

In order to investigate propagation regularity of hydraulic fractures in the mode of multi-well pads, numerical modeling of simultaneous hydraulic fracturing of multiple wells was conducted. The mathematical model was established coupling rock deformation with fluid flow in the fractures and wellbores. And then the model was solved by displacement discontinuity method coupling with implicit level set method. The implicit method was based on fracture tip asymptotical solution and used to determine fracture growth length. Simulation results showed that when multiple wells were fractured simultaneously, adjacent fractures might propagate towards each other, showing an effect of attraction other than repulsion. Fracture spacing and well spacing had significant influence on the propagation path and geometry of multiple fractures. Furthermore, when multiple wells were fractured simultaneously, stress reversal regions had a large area, and stress reversal regions were distributed not only in the area between fractures but also on the outside of them. The area of stress reversal regions was related to fracture spacing and well spacing. Results indicated that multi-well fracturing induced larger area of stress reversal regions than one-well fracturing, which was beneficial to generating complex fracture network in unconventional reservoirs.

Generalized Tricomi Problem for a Quasilinear Mixed Type Equation

In this paper,the Tricomi problem and the generalized Tricomi problem for a quasilinear mixed type equation are studied.The coefficients of the mixed type equation are discontinuous on the line,where the equation changes its type.The existence of solution to these problems is proved.The method developed in this paper can be used to study more difficult problems for nonlinear mixed type equations arising in gas dynamics.