设计减振装置消除车削振动及噪声

设计减振装置并增加辅助支承,提高了工件系统的刚度,可以消除车削振动及噪声。     

基于CAE分析的注塑模具浇口位置研究

应用CAE中的Moldflow软件中的充填、冷却、流动及翘曲分析技术,对注塑模具设计中的浇口位置选择作了详细的分析研究.在进行注塑模具设计时,首先在理论上优化浇口位置,可以改变传统的通过试模修模来改进模具的方法,从而节省时间.降低模具设计与制造成本.     

利用Autolisp语言实现常用轴段的设计与绘图

为了使轴类零件的设计与绘图更规范化,提高设计效率,开发常用轴段的设计与绘图程序。     

V.R.C.机器人机身旋转电液伺服阀控马达系统仿真研究

介绍了V．R．C．机器人机身旋转电液伺服控制系统的原理，建立了系统数学模型，用MATLAB进行仿真。结果表明系统设计合理，具有满意的稳定性能。     

一种简明易用的结构优化的包络函数

利用包络函数可以使数目庞大的多个约束转化为一个约束或少数几个约束,目前流行的是K-S熵包络函数。介 绍K-R.M.S.均方根包络函数,与熵包络函数相比,这种包络函教具有表达简捷、意义明确、方便易用的优点。     

分析MasterCAM裁剪命令的使用特点

一般MasterCAM软件操作者都觉得这个软件中的裁剪命令不是很好用,其裁剪结果不好判断,应用规律难以掌握,特别是关于三个物体的裁剪比较难.其实不然,就笔者所使用的一些CAD软件中--比如AutoCAD,UG,Pro/E等--还偏属这个软件的裁剪功能最强大,现详细分析如下.     

视频编解码器中去方块滤波器的实现

基于块的混合编码是H.261、H.263、H.264、JPEG、MPEG的基本编码方案,然而在量化系数比较大的情况下会产生明显的方块效应.对H.263+中的针对DCT变换的去方块滤波器和H.264中针对整数变换的去方块滤波器进行分析、比较并实现.结果表明,该滤波器对解码图像质量有明显的改善.     

S7-300在啤酒工业C.I.P中的应用

C．I．P（Clearing In Plac）是食品行业采用一系列的清洗济和消毒剂，对生产食品的设备、管道等，在无须进行拆卸和安装下进行周期性自动清洗和消毒的系统。与传统手工清洗相比，卫生、方便、工作效率高。     

G.O.-AMSAA模型在数控系统可靠性增长中的应用

数控磨床是工业制造的基础,因此,数控磨床的可靠性关系到生产效率的高低,针对数控磨床的可靠性提高,对采集的国内某型号数控磨床故障数据进行分析,通过所建立的功能树结构图发现数控系统可靠性的提高对该磨床整机可靠性提高起到关键作用,因此,找出该型号数控系统的薄弱环节并且对这些薄弱环节提出了一些改进措施。对改进完的数控系统进行G.O.-AMSAA模型线性拟合,通过对采取改进措施前、后的拟合曲线进行对比,对比结果充分的证明了G.O.-AMSAA模型在提高数控系统可靠性中的作用。     

二烷基二硫代磷酸钕作为锂基脂添加剂的极压抗磨作用机理

合成了二正十六烷基二硫代磷酸阴离子与稀土离子（Ｎｄ＾３＋）的中性络合物，考察了具有类似配体结构的稀土和过渡金属（Ｚｎ）络合物对锂基脂摩擦学性能的影响，通过Ｘ光光电子能谱对添加剂的作用机理进行了研究。     

用普通水玻璃砂铸造高精度齿条工艺方案的优化

齿条的齿部尺寸精度和表面平整度要求较高,采用普通水玻璃砂手工生产方式铸造难度很大,试制过程往往解决了一些问题又出现一些新的问题,在不断的实践摸索中,我们终于找到最优工艺方案。采用该方案生产出2640件齿条,全部符合质量要求。     

Direct electron imaging in electron microscopy with monolithic active pixel sensors

A new imaging device for dynamic electron microscopy is in great demand. The detector should provide the experimenter with images having sufficient spatial resolution at high speed. Immunity to radiation damage, accumulated during exposures, is critical. Photographic film, a traditional medium, is not adequate for studies that require large volumes of data or rapid recording and charge coupled device (CCD) cameras have limited resolution, due to phosphor screen coupling. CCD chips are not suitable for direct recording due to their extreme sensitivity to radiation damage. This paper discusses characterization of monolithic active pixel sensors (MAPS) in a scanning electron microscope (SEM) as well as in a transmission electron microscope (TEM). The tested devices were two versions of the MIMOSA V (MV) chip. This 1M pixel device features pixel size of 17 x 17 microm(2) and was designed in a 0.6 microm CMOS process. The active layer for detection is a thin (less than 20 microm) epitaxial layer, limiting the broadening of the electron beam. The first version of the detector was a standard imager with electronics, passivation and interconnection layers on top of the active region; the second one was bottom-thinned, reaching the epitaxial layer from the bottom. The electron energies used range from a few keV to 30 keV for SEM and from 40 to 400 keV for TEM. Deterioration of the image resolution due to backscattering was quantified for different energies and both detector versions.     

A method for fabricating protein patterns on the octadecyltrichlorosialne(OTS) surface through paper swabbing

A simple protein patterning procedure was developed for fabricating clean protein patterns ranging from nanometer to sub-millimeter scale. A carboxylic acid-terminated chemical pattern was fabricated first through the local probe oxidation on the octadecyltrichlorosilane (OTS) film under 100% relative humidity at the first. After incubating the chemical pattern in a protein solution, the sample was swabbed with a piece of ChemWipe paper to selectively remove the non-specifically adsorbed protein. After the swabbing, only the specifically immobilized protein remained on the surface, forming a protein pattern on the chemical template with a very clean background. In our approach, an anti-fouling surface or vigorous rinsing is not required, which simplifies the protein patterning process. As a demonstration of the capability of this protein patterning approach, we fabricated the lysozyme and catalase patterns on the OTS surface. Both patterns were clean and bioactive.     

In situ measurements and transmission electron microscopy of carbon nanotube field-effect transistors

We present the design and operation of a transmission electron microscopy (TEM)-compatible carbon nanotube (CNT) field-effect transistor (FET). The device is configured with microfabricated slits, which allows direct observation of CNTs in a FET using TEM and measurement of electrical transport while inside the TEM. As demonstrations of the device architecture, two examples are presented. The first example is an in situ electrical transport measurement of a bundle of carbon nanotubes. The second example is a study of electron beam radiation effect on CNT bundles using a 200 keV electron beam. In situ electrical transport measurement during the beam irradiation shows a signature of wall- or tube-breakdown. Stepwise current drops were observed when a high intensity electron beam was used to cut individual CNT bundles in a device with multiple bundles.     

Effects of dopamine concentration on energy transfer between dendrimer–QD and dye-labeled antibody

The Unified Parkinson's Disease Rating Scale (UPDRS) is currently used to assess Parkinson's disease, and is a key method for determining the progression of disease based on the gross findings of patients. However, this method cannot quantify the extent of disease of patients, which means the administration of drugs cannot be determined on a real-time basis. Thalamotomy also causes discomfort and pain to the patients, and adversely affects treatment as it is performed following the onset of symptoms. Accordingly, the dopamine concentration, which is one of the key factors in determining this disease, needs to be detected quantitatively at ordinary times. Hence, the development of a bio-kit or a bio-sensor is essential for effectively prescribing the correct dopamine concentration in a customizable manner. In this study, the effect of dopamine level on this phenomenon was observed using the Forster resonance energy transfer (FRET) phenomenon generated between a donor and acceptor. By confirming the photoluminescence (PL) and lifetime data, it was demonstrated that the degree of energy transfer increased with increasing dopamine concentration. To apply this phenomenon to an optical sensor, a glass surface was modified with a quantum dot (QD)-encapsulated dendrimer, and analyzed using the contact angle and ATR-FTIR. The topology of surface was determined by an atomic force microscope (AFM).     

Microstructure of a newly developed gamma' strengthened Co-base superalloy

The microstructure of a newly developed Co-base superalloy with enhanced high-temperature strength has been investigated using transmission electron microscopy (TEM) and three-dimensional atom probe (3DAP) techniques. It mainly consists of a typical gamma/gamma' (FCC/L1(2)) structure and a plate-shaped AB3-type (Ni,Co,Cr)3(Ti,Al) intermetallic compound with hexagonal structure (a approximately 5.1A and c approximately 12.5A). gamma' is formed with a bimodal distribution and fine gamma' has a cuboidal morphology. Cr and Co are enriched in the gamma phase, while Ti, Al and Ni are enriched in the gamma' phase. W and Mo are more or less uniformly distributed in both gamma and gamma'. Chemical composition analysis by 3DAP suggests that the plate-shaped phase has a higher Ti and lower Al content compared to that of gamma' phase, and the concentration of Ti, Co and Ni has a periodic variation along c-axis with a period of 12.5A in the plate-shaped phase.     

Vector field electron tomography of magnetic materials: theoretical development

The theory of vector field electron tomography, the reconstruction of the three-dimensional magnetic induction around a magnetized object, is derived within the framework of Lorentz transmission electron microscopy. The tomographic reconstruction method uses as input two orthogonal tilt series of magnetic phase maps and is based on the vector slice theorem. An analytical reconstruction of the magnetic induction of a single magnetic dipole is presented as a proof-of-concept. The method is compared to two previously reported approaches: a reconstruction starting from the gradient of the magnetic phase maps, and a direct reconstruction of the magnetic vector potential. Numerical examples as well as estimates of the reconstruction errors for a range of magnetic particle shapes are reported.     

In situ environmental TEM studies of dynamic changes in cerium-based oxides nanoparticles during redox processes

We apply in situ environmental transmission electron microscopy (ETEM) to study the dynamic changes taking place during redox reactions in ceria and ceria-zirconia nanoparticles in a hydrogen atmosphere. For pure ceria, we find that a reversible phase transformation takes place at 730 degrees C in which oxygen vacancies introduced during reduction order to give a cubic superstructure with a periodicity of roughly twice the basic fluorite lattice. We also observe the structural transformations taking place on the surface during reduction in hydrogen. The (110) ceria surface is initially constructed with a series of low-energy (111) nanofacets. Under strong reduction, the surface slowly transforms to a smooth (110) surface which was not observed to change upon re-oxidation. The surface transformation allows the reduced surface to accommodate a high concentration of oxygen vacancies without creating a strong perpendicular dipole moment. In the ceria-zirconia system, we are able to use ETEM to follow the redox activity of individual nanoparticles and correlate this property with structure and composition. We find considerable variation in the redox activity and interpret this in terms of structural differences between the nanoparticles.