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1.
本文讨论了互换性定律的族系,研究了非训练行为不准确现象,讨论了行为互换性的需求,推论了行为互换性定律的存在,建立了行为互换性的概念,创建了行为互换性定律的命题及其数学模型,详述了定律的内涵,分析了行为互换性与其他互换性的关系,讨论了行为互换性定律的对象范围、互换类型、自身特点和作用意义,对行为互换性定律进行了验证分析,讨论了行为互换性定律的应用,并给出了应用例子。  相似文献   

2.
某型车辆驾驶室内部噪声分析研究   总被引:2,自引:0,他引:2  
建立了某型车辆驾驶室结构的三维有限元模型,对驾驶室进行了试验模态分析,得到了模态参数,检验和修正了结构的三维有限元模型,对驾驶室结构进行了动态响应分析.采用边界元法进行了驾驶室内部声学特性研究,对驾驶员耳旁的声压和声学灵敏度进行了分析,得出了驾驶室内声场的声学特性,对驾驶室结构提出改进措施,有效地降低了车内噪声.  相似文献   

3.
标准化学科几何互换性定律的创建   总被引:1,自引:1,他引:0  
本文讨论了规律和定律的关系和特点,讨论了几何互换性的本质关系,推论了互换性定律的存在,创建了动配合互换性定律、定位配合互换性定律、紧配合互换性定律,建立了定律的命题、数学模型和关系模型,详述了每个定律的内涵,创建了支持互换性工程应用的几何互换性空间,讨论了互换性定律的应用,创建了广泛适用的互换性空间。  相似文献   

4.
本文讨论了互换性的新模式——功能互换性,阐述了功能互换性的概念和特点,创建了功能互换性的命题,解读了功能互换性命题的内涵及其数学模型,给出了功能互换性的关注情形,探讨了功能互换性的适用范围和作用意义,验证了功能互换性定律的有效性,说明了功能互换性定律的应用,并给出了指导功能互换性定律应用的实例。  相似文献   

5.
从整体上分析了企业标准化管理系统的内容,探讨了计算机应用于企业标准化管理的可行性。根据系统需求分析选择了以FOXBASE+为软件工具,从系统的内在关系入手,划分了功能模块,确立了系统软件结构,确定了数据库的结构。并对企业标准化管理软件作了详细描述,进一步阐述了在企业标准化管理中,应用计算机的具体作用及如何推广应用。  相似文献   

6.
经过两天的紧张工作,中国缩微摄影技术协会第三次全国会员代表大会已经圆满完成了各项议程。大会期间选出了第三届理事会,召开了三届一次理事会议,选举了常务理事、理事长、副理事长和秘书长,推举了名誉理事长,批准了十四位老同志为荣誉会员,聘任了副秘书长和各工作委员会的主任委员。  相似文献   

7.
麦绿波 《标准科学》2012,(2):6-10,16
本文创建了自然态劳动作业模型,对自然态劳动作业模型的特点进行了分析,创建了标准化的劳动作业模型,对标准化劳动作业模型的特点作了深入的分析,建立了工业生产的机群模型和流水模型,并进行了对比分析,对自然态劳动作业模型和标准化作业模型进行了对比分析,讨论了标准化作业的价值作用和效果。  相似文献   

8.
中国人在食品中完成了化学扫盲:从大米里我们认识了石蜡,从火腿里我们认识了敌敌畏,从成鸭蛋、辣椒酱里我们认识了苏丹红,从火锅里我们认识了福尔马林,从银耳、蜜枣里我们认识了硫磺,从木耳里我们认识了硫酸铜,从保鲜膜中我们认识了DEHA(己二酸二异辛酯),从有毒奶瓶中我们认识了双酚A,今天,从奶粉中又让我们知道了三聚氰胺,  相似文献   

9.
研究了一种新型多通道光电扭矩传感器,通过光电方法测量旋转轴的扭转角来获得动态扭矩,采用虚拟仪器的思想,基于LabVIEW测试平台实现了对扭矩值的实时显示.应用动态扭矩加载器对扭矩值进行了动态校准.该传感器系统减少了硬件设备,缩短了开发周期,提高了测量精度.  相似文献   

10.
《互联网时代》是以全球背景下的视野,聚焦了历史、聚焦了文化、聚焦了社会功能,通过十集的影像表达,缔造了一个时代所呈现的互联网巨大变革,满足了受众,创造了经济效益,开创了中国纪录片史上的又一个里程碑,同时创造了较高的社会现实意义。完成了近乎完美的中国映像,为中国纪录片占有国际地位奠定了社会基础。  相似文献   

11.
Modelling of the mechanical behavior of unidirectionally fiber-reinforced ceramic matrix composites (CMC) is presented by the example of SiC/SiC. The starting point of the modelling is a substructure (elementary cell) which includes on a micromechanical scale the statistical properties of the fiber, matrix and fiber–matrix interface and their interactions. The substructure is chosen in such a way that a macrostructure representative of the whole structure can be modelled from a suitable number of substructures. The typical damage behavior of ceramic composites is modelled by taking fiber and matrix cracks into account. Cracks are inserted into the substructure by reducing the elastic coefficients of the material. The fracture criterion used is a surface represented by a spheroid in the principal stress space. The crack direction is determined by the criterion of the energy release rate. Interfacial behavior is simulated by consideration of fiber–matrix debonding and frictional sliding. The numerical evaluation of the model is accomplished by means of the finite element method (FEM). The effect of important parameters such as the fiber volume fraction or the fiber Weibull-shape parameter on the nonlinear behavior of the substructure is examined. Finally, a macrostructure is modelled to show the effects of these important parameters on the mechanical behavior of the whole structure.  相似文献   

12.
The method by which micrometer-sized particles are arranged, is described. An electrified pattern is drawn on a polished insulating substrate using a SEM with a CAD facility. The substrate is dipped in a suspension of particles. The particles adhere to the substrate and form the pattern corresponding to the electrified pattern by the electrostatic force. The arranged particles are fixed by coating with a fluoride polymer of thin film. The method is applicable to the production of an inflammable gas sensor.  相似文献   

13.
The transient scattering of Rayleigh-Lamb waves by a surface-breaking crack in a plate is investigated in both time and frequency domains by using the hybrid numerical method which combines the finite element discretization of the vicinity of the crack with the Green's function integral representation of the exterior scattered field. The frequency domain response is obtained by solving a set of large sparse unsymmetric complex matrix equations, elements of which are stored in a compacted data structure, by the biconjugate gradient method. The time domain solution is then obtained by using FFT. The source function generated by a steel ball impact is extracted by a direct integration technique. It is then used to simulate some available experimental results. Good agreement has been obtained. Numerical and experimental results show the effect of the crack more in the near field than far away.  相似文献   

14.
This paper presents a finite element topology optimization framework for the design of two‐phase structural systems considering contact and cohesion phenomena along the interface. The geometry of the material interface is described by an explicit level set method, and the structural response is predicted by the extended finite element method. In this work, the interface condition is described by a bilinear cohesive zone model on the basis of the traction‐separation constitutive relation. The non‐penetration condition in the presence of compressive interface forces is enforced by a stabilized Lagrange multiplier method. The mechanical model assumes a linear elastic isotropic material, infinitesimal strain theory, and a quasi‐static response. The optimization problem is solved by a nonlinear programming method, and the design sensitivities are computed by the adjoint method. The performance of the presented method is evaluated by 2D and 3D numerical examples. The results obtained from topology optimization reveal distinct design characteristics for the various interface phenomena considered. In addition, 3D examples demonstrate optimal geometries that cannot be fully captured by reduced dimensionality. The optimization framework presented is limited to two‐phase structural systems where the material interface is coincident in the undeformed configuration, and to structural responses that remain valid considering small strain kinematics. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

15.
This article concerns a proximal-point algorithm with time penalization. The case where the cost of moving from one position to a better one is penalized by the time taken by the agent for the decision-making is studied and the restriction employing the penalty method is incorporated. It is shown that the method converges monotonically with respect to the minimal weighted norm to a unique minimal point under mild assumptions. The gradient method is employed for solving the objective function, and its convergence is proven. The rate of convergence of the method is also estimated by computing the optimal parameters. The effectiveness of the method is illustrated by a numerical optimization example employing continuous-time Markov chains.  相似文献   

16.
The application of a Hadamard transform technique to microchip electrophoresis is described. The sample is electrokinetically injected into a separation channel and is then detected by diode laser-induced fluorometry. The sample and buffer solutions are introduced into the channel by controlling the high voltages applied to the solutions, according to a code determined by a Hadamard matrix. The S/N ratio of the signal in the electropherogram can be improved by a factor of 5 in comparison with that obtained by a conventional single-injection method, although an 8-fold improvement is theoretically predicted when a 255-order matrix is used.  相似文献   

17.
流线型回转体外形设计综述与线型拟合   总被引:1,自引:0,他引:1       下载免费PDF全文
杜月中  闵健  郭字洲 《声学技术》2004,23(2):93-97,101
综述了流线型回转体外形设计的主要方法:(1)具有精确数学表达式的几何组合外形曲线;(2)用源汇法设计回转体外形曲线;(3)用离散外形坐标型值表示的回转体线型。给出了流线型离散型值回转体线型的拟合解析表达式。这些外形设计方法与拟合解析表达式具有广泛的工程实用价值。  相似文献   

18.
主动测量信息的智能化处理与控制   总被引:2,自引:0,他引:2  
简德 《工程设计学报》2000,7(4):101-104
主动测量仪正朝着智能化和多参数测量的方向发展,传感器检测信号的滞后特性是产生动态误差的主要原因,本文提出了一种对被测信息进行智能化处理的方法,通过在线辨识传感器滞后时间常数Tm,再利用校正(补偿)的方法减少或消除滞后时间常数Tm的影响,从而减少或消除动态误差,实现测量与控制熔为一体、主动测量技术的自动化。  相似文献   

19.
不规则压延件展开毛料的几何计算法   总被引:3,自引:1,他引:2  
不规则压件展开毛料的几何计算,可分为二步:展开和修正。  相似文献   

20.
In this paper a practical approach to design, based on the concept of selection, is presented. The approach involves: first, the generation of alternative concepts using ideation tecniques; second, the selection of the ‘most-likely-to-succeed’ concepts for further development into feasible alternatives; third, the formulation and solution of selection-decision-support problems to rank the feasible alternatives in order of preference using multiple attributes.The method presented in this paper is a combination of the methods proposed by Pugh and by Mistree and Muster. The former method is appropriate for use in concept selection, which is characterized by many alternatives and essentially insight-based ‘soft’ information. The latter method is appropriate when there are few alternatives and a mix of science-based ‘hard’ and insight-based ‘soft’ information. The method presented by Mistree and Muster is therefore used to formulate and solve the selection-decision-support problem. The design example used in this paper is a modified version of that used by Pugh.  相似文献   

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