逆向工程中自由曲面重构的算法探讨

介绍常用的自由曲面反求的几种算法和特点及归类 ,探讨目前曲面重构过程中的难点、热点问题。     

基于正交-交互式遗传算法的产品造型设计

为提高概念设计的效率,提出一种基于正交-交互式遗传算法的产品造型设计方法.在获取、表征造型特征的基础上,采用正交分析来精简遗传种群空间,提高收敛速度;同时,以共识满意度作为适应度函数,优化评价机制,达到减小主观评价误差的目的.另外,可视化的界面有利于特征偏好选取,减轻用户交互的心理负担.实例研究表明,与普通交互式遗传算法相比,正交-交互式遗传算法能以较少的交互代数达到较高的适应值,具有更好的可行性和实用性.     

CAPTURE EFFECT OF ELECTRORHEOLOGICAL SUSPENSIONS IN FLOW FIELD

According to the results of experiments and theoretical analysis,a phenomenon called “capture effect” is put forward,which could be used to describe the particles dynamic behavior of electrorheological (ER) suspensions. Then a “structure-force” mathematical model is established to explain this effect based on electrostatic energy density equation. The analysis results show that the dynamic coupling process of ER suspensions under an external electric filed is the function not only of the electric intensity,but also of the dielectric properties and the structure form.     

基于“三针法”的内螺纹测量装置的研究与设计

基于"三针法"螺纹测量原理,研究了内螺纹主要参数之间的相互关系,设计了可测量普通螺纹、梯形螺纹、锯齿形螺纹等内螺纹的中径、牙型角和螺距的测量装置。     

智能单据自动扫描识别分类装置

介绍了一种基于单片机控制的智能单据自动扫描识识别分类装置.该装置综合运用了OCR符号识别技术、数据库技术、单片机控制技术及机械传动设计,实现单据的自动扫描和归类纠错管理,并可根据具体使用情况进行二次开发.     

注塑模具CAPP零件信息的描述与处理

提出了注塑模具CAPP关于零件信息描述及处理的一种实用方法。对结构类零件建立了编码系统进行信息描述，利用塑件形状特征对成型类零件进行信息描述。介绍了注塑模具零件相似度计算、检索和工艺生成的方法。     

矿用对旋轴流式主通风机叶轮有限元分析

通过建立有限元分析模型,对叶轮的主要零部件进行应力、变形分析,据其结果考虑减少应力集中和强度裕量,改进叶轮结构.样机试验表明,叶轮质量减小了26%,降低了风机的噪声和振动,改善了配套电机轴承的受力状况,提高了使用寿命.该分析方法在同类产品中有应用的可能性.     

金属材料磨损失效及防护

文章从金属材料磨损失效的危害出发,结合金属材料的磨损原理,分析了金属材料磨损失效的基础形式,并结合具体的问题给予了可行性的建议。     

Unexpected Sole Enol‐Form Emission of 2‐(2′‐Hydroxyphenyl)oxazoles for Highly Efficient Deep‐Blue‐Emitting Organic Electroluminescent Devices

Considerable efforts have been devoted to the development of highly efficient blue light‐emitting materials. However, deep‐blue fluorescence materials that can satisfy the Commission Internationale de l'Eclairage (CIE) coordinates of (0.14, 0.08) of the National Television System Committee (NTSC) standard blue and, moreover, possess a high external quantum efficiency (EQE) over 5%, remain scarce. Here, the unusual luminescence properties of triphenylamine‐bearing 2‐(2′‐hydroxyphenyl)oxazoles ( 3a–3c ) and their applications in organic light‐emitting diodes (OLEDs) are reported as highly efficient deep‐blue emitters. The 3a ‐based device exhibits a high spectral stability and an excellent color purity with a narrow full‐width at half‐maximum of 53 nm and the CIE coordinates of (0.15, 0.08), which is very close to the NTSC standard blue. The exciton utilization of the device closes to 100%, exceeding the theoretical limit of 25% in conventional fluorescent OLEDs. Experimental data and theoretical calculations demonstrate that 3a possesses a highly hybridized local and charge‐transfer excited state character. In OLEDs, 3a exhibits a maximum luminance of 9054 cd m^?2 and an EQE up to 7.1%, which is the first example of highly efficient blue OLEDs based on the sole enol‐form emission of 2‐(2′‐hydroxyphenyl)azoles.     

Predictor-based control for an inverted pendulum subject to networked time delay

The inverted pendulum is considered as a special class of underactuated mechanical systems with two degrees of freedom and a single control input. This mechanical configuration allows to transform the underactuated system into a nonlinear system that is referred to as the normal form, whose control design techniques for stabilization are well known. In the presence of time delays, these control techniques may result in inadequate behavior and may even cause finite escape time in the controlled system. In this paper, a constructive method is presented to design a controller for an inverted pendulum characterized by a time-delayed balance control. First, the partial feedback linearization control for the inverted pendulum is modified and coupled with a state predictor to compensate for the delay. Several coordinate transformations are processed to transform the estimated partial linearized system into an upper-triangular form. Second, nested saturation and backstepping techniques are combined to derive the control law of the transformed system that would complete the design of the whole control input. The effectiveness of the proposed technique is illustrated by numerical simulations.