面向企业的CAD／CAM／CAPP／PDM／ERP集成系统

分析了目前机械制造企业的CAD/CAX应用概况，提出了一种面向企业的CAD/CAM/CAPP/PDM/ERP系统的集成框架和实施内容，以适应现代企业的需要。     

基于Pro／E的模具CAD／CAM

Pro/E是功能强大的三维CAD/CAM软件,应用十分广泛,在模具设计与制造行业占有显而易见的优势.本文介绍基于Pro/E的模具CAD/CAM技术.以一爪盘的模具设计与制造为例,应用Pro/E软件的Pro/MOLDESIGN和Pro/MANUFACTURING模块进行模具设计与数控加工,阐述了Pro/E模具设计与数控加工的过程和方法.实践证明应用Pro/E软件进行模具设计与制造具有独特的优越性.     

HPLC／ESI／MS／MS测定鸡肉中咪唑类兽药残留

The determination and identification method for the thiabendazole (TBZ) , 5-OH thiabendazole(5-OH TBZ) and 2-Aminosulfone albendazole(2-Aminosulfone ALB) residues in chicken meat by HPLC/ESI/MS/MS was repored. The qualitative results are presented by the daughter ions from molecular ions [M H]^ of each target compound. The detective limit of the method is 0.01mg/kg for TBZ and 5-OH TBZ, 0.02mg/kg for 2-Aminosulfone ALB. The average recoverary is from 83% to 104% (n=10, the concentration of each compound is 0.02mg/kg to 1.0mg/kg).     

CAD／CAE／CAM的协同发展研究

随着电子计算机在机电产品的设计、分析、制造领域的深入应用,以CAD/CAE/CAM技术为代表的现代先进制造技术的出现改变了传统的设计、生产模式.21世纪的CAD/CAE/CAM系统将会朝着参数化、智能化、集成化、网络化方向发展.     

CAD／CAPP／CAM系统中的图形数据库开发

阐述零件图形数据库开发原理和方法,解决CAD/CAPP/CAM系统中零件设计和制造信息处理、传递的关键问题.将类零件设计和制造信息定义为设计特征、管理特征、工艺特征,借助交互式参数化设计方法进行特征识别,构造零件设计模型、管理模型、加工模型,从而建立供CAD/CAPP/CAM系统使用的类零件图形数据库.     

CAD／CAPP／CAM集成方法与应用

对CAD/CAPP/CAM集成方法的的小齿轮为例详细地阐述了CAD/CAPP/CAM集成系统的总体设计方案及运行过程.     

基于Pro／E椭圆齿轮的CAD／CAM技术

基于Pro/E软件提供的高级开发工具包Pro/TOOLKIT,利用Visual C++6.0的集成开发环境,采用多进程方式开发出椭圆齿轮参数化设计系统;利用Pro/NC加工模块以椭圆齿轮线切割加工为例,实现其数控加工的模拟过程.椭圆齿轮的CAD/CAM解决了椭圆齿轮设计中的复杂计算和三维实体造型难的问题,提高设计精度、缩短产品开发周期,保证了产品质量.     

GPIB／PXI／VXI仪器转向LXI的探讨

本文介绍了GPIB/PXI/VXI仪器的优势和不足,从易用性、灵活性和扩展性等几个方面阐述了GPIB/PXI/VXI仪器应转向LXI的理由,从而解决降低成本、缩小系统尺寸、简化集成、提高吞吐率.以及为硬件和软件的重复利用提供更多机会等问题,使网络切实地介入现代测量与测控的全过程,为开发各种系统提供了广阔空间和选择的余地.     

模具设计制造中CAD／CAE／CAM技术的应用研究

模具作为一种高附加值和高技术密集型的产品,其技术水平的高低成为衡量一个国家制造水平的重要标志,而模具工业的发展关键是模具技术的进步.本文着重介绍了模具CAD/CAE/CAM的现状,分析了模具CAD/CAE/CAM技术存在的主要问题,并探讨了其发展趋势.     

注塑模CAD／CAE／CAM的发展和应用

常用塑料如聚氯乙烯、聚乙烯、聚苯乙烯、ABS等,在20世纪40年代才问世,注塑模具的历史也不过50余年,但发展速度却异常迅速,塑料制品已经成为工业部门和日常生活中不可缺少的重要组成部分。塑料工业对模具的迫切需要正是注塑模CAD/CAE/CAM(计算机辅助设计、工程分析和制造)发展的原动力,而近30年塑料流变学、几何造型技术、数控加工以及计算机技术的突飞猛进更为注塑模CAD/CAE/CAM系统的开发创造了条件。 一、技术特点 注塑模CAD/CAM的重点在于注塑制品的几何造型、模具设计、绘图和数控加工数据以及指令的生成,而     

Cylindrical specimens for KIC of rocks

Stress intensity factors for pairs of diametrically opposite radial cracks on the inside of a jacketed pressurized hole in a thick cylinder have been calculated by using finite element technique. Burst tests on thick cylinder rock samples under above conditions have been performed and the K_IC values for Antrim Shale and Limestone determined. The method is very convenient for rocks whose samples are often available in form of cylindrical bars drawn as cores from underground drilling.     

Electron and light microscopy studies on the domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I ferroic boracites

The domain structures of Zn₃B₇O₁₃Cl, Zn₃B₇O₁₃Br and Zn₃B₇O₁₃I boracite single crystals were studied by means of polarized light in conjunction with electron microscopy. Single crystals of the three compositions were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 900 °C and were examined by polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For both PLM and SEM, the same as‐grown samples were used without having to resort to metallization of the crystal faces. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of these ferroelectric/ferroelastic materials previously observed between the crossed polars of an optical microscope. X‐ray diffraction analysis of the pulverized crystals was performed for this triad of halogen boracites containing zinc as a common metal.     

GT/CAD/CAPP/PDM/ERP系统集成研究

研究ETO生产方式下以成组技术为基础的CAD/CAPP/PDM/ERP的集成方法,包括面向CAD/CAPP/PDM/ERP的集成的成组信息编码,基于成组编码的CAD/PDM集成、CAPP/PDM集成和PDM/ERP集成.提出了基于成组技术的CAD/CAPP/PDM/ERP集成框架,研究了贯穿于CAD、CAPP、PDM与ERP系统的统一的成组编码方案和信息编码方案.     

基于太赫兹光谱的人参和西洋参鉴别

为了快速区分人参和西洋参,依据两者所含的人参皂苷在太赫兹波段具有不同指纹光谱,提出了一种基于人参皂苷的太赫兹光谱鉴别人参和西洋参的方法。采用MATLAB软件识别人参和西洋参的太赫兹光谱,同时根据太赫兹光谱特征并通过标准的主成分分析(PCA)区分出人参、西洋参。实验结果表明,基于太赫兹光谱的主成分分析可精确区分出人参、西洋参,并且还可以应用于其他类似物质的区分中。     

Analysis of the Rk surface roughness parameter proposals

European manufacturers have proposed a set of surface roughness parameters based on an examination of the variation in slope of the bearing ratio curve of a surface profile. It is shown, that the proposed procedure provides no useful information, and indeed is misleading, since the bearing ratio curve of even a normally-distributed random surface profile exhibits the expected variation in slope when plotted on rectangular coordinates. On the other hand, the desired information is readily obtained by a similar examination of the cumulative height distribution of a surface profile (the unity complement of the bearing ratio) when it is plotted on normal probability coordinates.     

永磁同步电机积分滑模观测器控制

对永磁同步电机观测器控制进行研究,针对传统滑模观测器存在控制精度低、系统抖振较大的不足,设计了一种永磁同步电机积分滑模观测器控制。积分滑模控制具有控制精度高、系统抖振小的特点。积分滑模观测器可以有效提高电机控制精度,增强控制系统抗干扰能力。采用饱和函数代替符号函数进行滑模控制律设计,降低控制系统固有抖振,使滑模控制动态性能提高。通过仿真验证了积分滑模观测器控制策略的可行性。     

Characterization of cast Al86Mn3Be11 alloy

An Al₈₆Mn₃Be₁₁ alloy cast into copper mould was subjected to metallographic investigation. The as-cast microstructure consisted of a quasicrystalline icosahedral phase (i-phase), Be₄AlMn phase and, occasionally, a hexagonal phase. Al-rich solid solution represented the dominant phase. The chemical compositions of phases were determined using AES. The composition of the Be₄AlMn slightly deviated from the stoichiometric composition, whereas the composition of the i-phase was approximately Al₅₂Mn₁₈Be₃₀, containing an appreciable amount of Be. The average composition of the hexagonal phase was Al₆₆Mn₂₁Be₁₃. Deep etching and particle extraction provided a deep insight into the three-dimensional morphology of the i-phase and the hexagonal phase, whereas Be₄AlMn was slightly attacked by the etchant. The i-phase was present predominantly in the form of dendrites and a rodlike eutectic phase. The hexagonal phase was primarily in the form of hexagonal platelets, whereas Be₄AlMn was rather irregular in shape. The morphology of the i-phase can be explained by predominant growth in 3-fold directions and the lowest energy of the 5-fold planes, leading to the faceting and adopting a pentagonal dodecahedron shape. The brightnesses of phases in the backscattered electron images were rationalized by determining their backscattering coefficients. TEM investigation showed considerable phason strain in the i-phase, and the polycrystalline nature of the Be₄AlMn phase.     

Investigation on the impact behavior of Al2O3-SiC-MgO nanoceramic/metal laminated composite

Lightweight laminated composites containing a ceramic front layer and a metallic backing layer were used in order to protect people, moving equipment, and mobile vehicles from high velocity impact and the increased mobility of mobile vehicles. In this study, by adding10 vol% SiC and 500 ppm MgO nanoscale particles on the microstructure of Al ₂ O ₃ matrix and applying optimum sintering conditions, ceramic performance against high-speed projectile impact was improved. To perform this investigation, a number of target samples with two different types of front layers (alumina and Al ₂ O ₃-SiC-MgO nanocomposite ceramic) were produced. Impact tests were conducted on these samples using 7.62 mm projectiles with a velocity of 820 ± 15 m/s. The amount of bulge and bending of the backing layer caused by impact tests was measured. The results of the impact tests on the samples made of Al ₂ O ₃-SiC-MgO nanocomposite ceramics and alumina were also compared and analyzed. The results indicate that the substitution of Al ₂ O ₃-SiC-MgO ceramic layer — which is proffered in this paper — instead of pure alumina ceramic layer, decreases the areal-density of the samples by at least 30% and improves mechanical properties by about a 60% increase in flexural strength and 100% growth of the energy distribution factor, which impressively increases impact energy absorption.     

Electron microscopy of crack/particle interactions in Al2O3/SiC nanocomposites

Crack/particle interactions in alumina/silicon carbide nanocomposites have been investigated by scanning electron microscopy and transmission electron microscopy, with cracks induced by Vickers microindentation. Intergranular cracks are frequently deflected into grains by SiC particles on grain boundaries inclined to the average direction of crack propagation. This mechanism is proposed to explain the change in the fracture mode from intergranular fracture for monolithic alumina to predominantly transgranular fracture for the nanocomposites. Neither stress-induced microcracking around SiC particles nor significant crack deflection by intragranular particles was found to occur in the nanocomposites. It is argued that an addition of nanoparticles may not be a promising approach for increasing the toughness of alumina.     

Near-field second harmonic imaging of the c/a/c/a polydomain structure of epitaxial PbZrxTi1–xO3 thin films

Near-field optical second harmonic microscopy has been applied to imaging of the c/a/c/a polydomain structure of epitaxial PbZr _x Ti_{1– x} O₃ thin films in the 0 <  x  < 0.4 range. Comparison of the near-field optical images and the results of atomic force microscopy and X-ray diffraction studies show that an optical resolution of the order of 100 nm is achieved. Symmetry properties of the near-field second harmonic signal allow us to obtain good optical contrast between the local second harmonic generation in c- and a-domains. Experimentally measured near-field second harmonic images have been compared with the results of theoretical calculations. Good agreement between theory and experiment is demonstrated.