并联微操作机构的研究与应用

结合微操作机器人的特点，对并联机构的性能特征进行了综合比较。分析研究了几种典型微操作机器人的结构特色、技术性能、应用背景等。并就目前微操作机构的研究势态，归纳出了微操作机构亟待解决的一些问题。根据微操作机器人的共性，总结出了微操作机器人机构选择及设计的准则。     

生物工程中的微操作机器人系统

简述了微操作在生物工程中的作用，着重当前国内外微操作机器人系统的发展状况。在广泛调研的基础上提出了理想并切实可行的面向生物工程的微操作机器人系统的物理结构。     

面向精密作业的三自由度球基微操作器运动学分析

针对微操作及微装配需求,研制了一种采用四分压电陶瓷管驱动的球基微操作器,建立了不同驱动方式下球基的运动学模型,分析了球基微操作器实现空间3自由度转动的运动学问题,给出了Adams仿真实验与系统测试实验结果,验证了模型与分析的正确性.     

大范围多目标微操作的目标视觉跟踪实现策略

针对在微操作中显微视野远小于操作域,多目标的快速定位及清晰的整体轮廓与高分辨率细微结构视野同时获取比较困难的问题,提出了采用基于小波分频编码的变焦策略对合成的全局视野显微图像进行变焦,实现了显微图像空间区域的连续变化,保证了微操作目标始终呈现在不同空间分辨率的屏幕视野中,为在大范围显微图像中实现微操作目标的快速定位提供了崭新的手段.     

微操作中批量目标的自动视野转换

近年来,随着微操作研究的不断发展和深入,批量目标微操作成为当前的研究热点之一.由于显微镜视野范围狭小,微操作过程中需要不断进行物镜转换和调焦工作.本文研制的全自动微操作平台将调焦和物镜转换改造为电动方式,实现了自动调焦和物镜自动转换功能.针对细胞图像的特点,本文提出了基于扫描线的归一化方差聚焦测度方法,并在此基础上,设计了相应的聚焦平面搜索策略.针对显微镜物镜转化器的特点,本文设计了自动物镜转换结构和控制方法,实现不同放大倍数物镜的转换.最后本文在细胞图像处理的实验中,构建了具有分层递阶结构的全局视野,验证了自动调焦和物镜自动转换的准确控制,为批量目标操作的自动化奠定了基础.     

基于显微视觉与微力觉柔顺混合控制的微操作机器人

简单介绍了一种基于显微视觉和微力觉柔顺混合控制的微操作机器人的系统构成，并重点介绍了显微视觉系统和微力控制系统的组成及工作原理。阐述了显微视觉伺服系统和力觉柔顺控制在微操作机器人中的作用。同时，基于视觉与力觉混合控制技术，以微小轴孔零件装配任务为研究目标，进行了微装配试验，并取得较好效果。     

纳米SiO2/环氧树脂复合材料性能研究

以纳米SiO2作为增强材料，制备纳米复合材料，研究了不同的纳米SiO2含量对纳米复合材料性能的影响，采用透射电镜对纳米SiO2粒子的分布进行了表征，采用正电子湮没技术（PALS）测试了自由体积的尺寸及浓度。结果表明，当纳米粒子SiO2含量为3％时，自由体积浓度最小，纳米复合材料的性能最佳。     

基于虚拟显微镜技术的微操作工具Z方向定位方法研究

在前期研究工作的基础上提出了在微操作的拟实环境中基于虚拟显微镜技术用“试探法”求解微操作工具Z方向高精度定位问题,并针对其三个关键点－确定合理的模糊度判据、噪声处理、确定定位部位,进行了理论分析和实验验证,证明了该方法是可行的。     

纳米靶向技术在智能释药系统的应用

智能纳米靶向释药载体能对外界环境的温度、pH值、电、磁、化学物质等的刺激信号做出响应，并控制药物按设定目标释放。根据不同机理，纳米靶向技术分生物靶向、理化靶向及复合靶向3种。综述了纳米靶向技术在智能释药系统的最新应用研究进展。随着纳米技术的进一步发展和现有技术的不断完善，纳米载体智能释药系统在实际应用中会大规模采用，为人类战胜疾病作出贡献。     

纳米碳粒子的表面功能化

以纳米碳粒子为原料，用化学表面修饰技术使纳米碳粒子表面功能化，将乙二氨基、氨荒酸基、硫脲基、脒基等官能团以共价键方式偶联在纳米碳粒的表面，制备出不同类型的纳米高分子络合吸附剂．吸附剂的粒径为4～8nm，功能团在纳米碳粒子的表面含量为1.1mmol／g。纳米高分子络合剂对过渡金属离子的吸附速率高、吸附量大并具有很高的选择性．     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...