冲裁和整修复合的精密轮廓件的加工

介绍了一种高效加工板状零件精密轮廓的方法——复合整修法，分析了工艺问题、模具结构及其主要的尺寸参数。     

模具刃口轮廓误差综合测量

模具在现代工业生产中,以生产率高、成本低和节约原材料等特点,在各行各业中得到了广泛应用。在以刃口轮廓精度决定制成品精度的模具中,检测和提高模具刃口轮廓精度意义重大。目前,大部分模具生产企业采用样板测量,这种测量方法要事先制造样板,生产周期长,成本高,样板的制造精度影响模具刃口轮廓的测量精度。另外,样板测量只能定性测量,无法为模具刃口轮廓精度的提高提供数据。三坐标测量机测量精度高,但对生产现场的环境要求太高。因此,我们针对模具生产的特点,研究开发了能用于模具生产现场的测量仪,本测量仪测量精度高,通用性强。     

B15阀体轮廓度超差及解决方法

通过对B15节流阀体铝合金压铸件的工艺分析、模具设计结构分析、模具制造工艺分析以及生产过程监控,发现B15齿轮箱轮箱面轮廓度超差主要是模具结构设计不完善,引起铸件顶出不平衡以及模具加工工艺不合理,导致模具镶块尺寸达极限尺寸等因素影响,采取更改模具结构及优化模具制造工艺方法解决了节流阀体压铸件轮廓度超差问题,缩短模具制造周期及提高铸件合格率。     

模具刃口轮廓误差的综合测量

介绍了模具刃口轮廓误差综合测量的原理以及直线、圆弧、任意曲线刃口轮廓的最佳拟合数学模型及误差评定方法,并结合冲裁模测量实例分析了测量系统的性能。     

三坐标测量机测量腔盘模具曲线轮廓度关键点分析

给出了腔盘模具曲线轮廓度测量的3个关键点。即在分析测量基准与加工基准怎样重合的基础上,给出了坐标系建立方法。在建立过模具旋转中心的平面的基础上,确定了母线扫描路径。在考虑模具加工后轮廓与建模轮廓存在偏差的基础上,正确处理了实测值,给出了所测母线的曲线轮廓度。     

模具二维轮廓铣削加工刀具轨迹的仿真模型

开发了模具二维轮廓铣削加工刀具轨迹生成系统,此系统在模具加工车间使用,按实际使用的刀具半径进行编程,直接在机床外部计算出无干涉的加工轨迹,加工时不用引入刀具半径补偿,避免了加工干涉。系统还具有直观、简单的图形用户界面及刀具轨迹可视化功能,在模具的生产制造中有着一定的实用价值,而且对于其它类型工件二维轮廓加工也同样适用。     

基于模板配准的零件轮廓缺损检测

基于机器视觉的机器零件轮廓破损检测在产品质量检测中具有重要作用.根据在线检测速度的要求,对于利用模板轮廓进行零件轮廓缺损检测,提出了轮廓校正和轮廓极坐标表示方法,有效地解决了快速性和模板轮廓与被测轮廓采样点不一致的问题.实验结果表明了本文算法的有效性,为零件轮廓破损快速检测提供了有效途径.     

数控万能水切割机自动编程系统的基础问题研究

利用AutoCAD的二次开发工具ObjectARX2000开发水切割机的自动编程系统,重点分析了AutoCAD二维图形信息的提取、图形信息的排序处理和区分零件图形内外轮廓的具体方法,并以实例验证了该方法的可行性。     

注射模具并行工程的研究

本文分析了注射模具开发过程中市场调查，塑料制品设计，模具设计，模具原材料的购买，模具加工，装配，试模，用户信息反馈等各个环节的功能，作用及时效性，讨论了用并行工程的方法对塑料模具进行开发可行性。最后阐述了实行注射模并行工程所需的各种关键技术。     

目标识别在激光水平尺光点精度检测中的应用

对激光水平尺激光光点精度检测中的目标识别算法进行了深入探讨,提出了两种目标识别的方法,并对这两种方法进行了分析和比较。     

低温密封酸溶——高分辨电感耦合等离子体质谱法测定地质样品中50个微量元素的评价

The method based on the determination of trace elements in geological samples by sector high resolution inductively coupled plasma mass spectrometry with mixed acid digestion procedure has been evaluated. The evaluation show that the results of 29 elements including Li, Cr, Co, Ni, Cu, Zn, Ga, Rb, Y, Cs, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Tl, Bi, Th and U are satisfactory; V, Sr, Nb, Mo, In, Sb, Ba and Pb are acceptable; Sc, Cd, Hf, Ti, Mn, Fe, Ge and Sn have of large deviations, Be, Ta, Zr, As and Se are worse.     

微波消解-电感耦合等离子体质谱法测定食品中18种元素

建立了食品中钠、镁、铝、钾、钙、钒、铬、锰、铁、镍、铜、锌、砷、硒、镉、锡、汞、铅的电感耦合等离子体质谱（ICP–MS）测定方法。样品经过微波消解,在线加入内标校正基体效应,通过修正方程校正质量数干扰,各元素校正曲线的相关系数均大于0.9995。对多种国家生物标准物质进行验证,测定值与标准值相符,相对标准偏差RSD（n=6）小于8.71%,加标回收率为71.8%～109.5%。     

The structure and function of auditory chordotonal organs in insects

Insects are capable of detecting a broad range of acoustic signals transmitted through air, water, or solids. Auditory sensory organs are morphologically diverse with respect to their body location, accessory structures, and number of sensilla, but remarkably uniform in that most are innervated by chordotonal organs. Chordotonal organs are structurally complex Type I mechanoreceptors that are distributed throughout the insect body and function to detect a wide range of mechanical stimuli, from gross motor movements to air-borne sounds. At present, little is known about how chordotonal organs in general function to convert mechanical stimuli to nerve impulses, and our limited understanding of this process represents one of the major challenges to the study of insect auditory systems today. This report reviews the literature on chordotonal organs innervating insect ears, with the broad intention of uncovering some common structural specializations of peripheral auditory systems, and identifying new avenues for research. A general overview of chordotonal organ ultrastructure is presented, followed by a summary of the current theories on mechanical coupling and transduction in monodynal, mononematic, Type 1 scolopidia, which characteristically innervate insect ears. Auditory organs of different insect taxa are reviewed, focusing primarily on tympanal organs, and with some consideration to Johnston's and subgenual organs. It is widely accepted that insect hearing organs evolved from pre-existing proprioceptive chordotonal organs. In addition to certain non-neural adaptations for hearing, such as tracheal expansion and cuticular thinning, the chordotonal organs themselves may have intrinsic specializations for sound reception and transduction, and these are discussed. In the future, an integrated approach, using traditional anatomical and physiological techniques in combination with new methodologies in immunohistochemistry, genetics, and biophysics, will assist in refining hypotheses on how chordotonal organs function, and, ultimately, lead to new insights into the peripheral mechanisms underlying hearing in insects.     

微波消解-电感耦合等离子体质谱法同时测定茶叶中42种元素

建立了电感耦合等离子体质谱法（IcP—Ms）标准模式和优化的碰撞池模式（CCT）结合同时测定茶叶中Li、Be、Mg、Al、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、As、Se、Sr、Mo、Ag、Cd、Sn、Sb、Cs、Ba、Tl、Pb、Bi和16种稀土元素共42种元素的方法。样品经过微波消解,以Ge、In、Re为内标消除基体干扰,通过碰撞池技术消除多原子质谱干扰测定上述元素。对于所测元素校准曲线的相关系数均大于0．9990,回收率范围为90％-110％,相对标准偏差为0．22％-3．97％,大部分元素检出限均小于0．5μg·kg^-1。该方法简便、省时、准确、灵敏度高,适用于实际样品的检测。     

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Huge clusters of embryonic stem cells in human embryos: A morphologic study

Background: Nothing is known about huge clusters (HC) of embryonic stem cells (ESC) in human fetal organs (HFO). Aim: To know the status of HC‐ESC in HFO. Methods: Morphology and immunohistochemistry (IHC) in 32 HFO of 7–40 gestational weeks (GW). Results: HC‐ESC were seen in many HFO including central nervous system, spinal cords, spine, soft tissue, bone, skin, thyroid, lung, liver, pancreas, gall bladder, extrahepatic bile duct, adrenal, kidney, bladder, foregut, midgut, hindgut, female and male genital organs, and neurons. HC‐ESC's were composed of two populations depending on constituting cells. One were large cells with ample acidophilic cytoplasms with vesicular nuclei and nucleoli. The other were small cells with scant cytoplasm with hyperchromatic nuclei without nucleoli, resembling lymphocytes. The HC‐ESC were frequently showed neuronal differentiation. HC‐ESC were positive for NCAM, synaptophysin, NSE, chromogranin, PDGFRA, AFP, ErbB2, bcl‐2, KIT, MET. They were negative for CD45, CD3, CD20, EMA, CEA, CA19‐9, cytokeratin (CK) 7, CK8, CK18, CK19, MUC1, MUC2, MUC5AC, and MUC6. The mean Ki‐67 labeling index (LI) was 13% ± 7%. HC‐ESC showed a little glycogen but lacked mucins. These HC‐ESC were seen in 7–25 GW, and they were rarely seen in 26–40 GW. Conclusions: The morphology, IHC, and ontogeny of HC‐ESC were described. Microsc. Res. Tech. 77:825–831, 2014. © 2014 Wiley Periodicals, Inc.     

Epibiotic microorganisms on copepods and other marine crustaceans

Although the occurrence of microbial (algal, protozoan, bacterial, and fungal) epibionts on marine crustaceans and other invertebrates has been documented repeatedly, the ecological context and significance of these relationships generally are not well understood. Recently, several studies have examined the population and community ecology of algal and protozoan epibionts on freshwater crustaceans. Even so, the study of microbial epibionts in aquatic environments is still in its infancy. In this review, we summarize associations of microalgae, protozoans, and bacteria with marine crustaceans, especially copepods. We note differences and commonalities across epibiont taxa, consider host-epibiont cycling of nutrients, generate hypotheses relevant to the ecology of the host and the epibiont, and suggest future research opportunities. Microsc. Res. Tech. 37:116–135, 1997. © 1997 Wiley-Liss, Inc.     

Assessment of PM-EDM cycle factors influence on machining responses and surface properties of biomaterials: A comprehensive review

Powder mixed-electro discharge machining (PM-EDM) is recently evolving machining technique which can simultaneously remove and modify the machined surface through thermo-electrical process. It is a modified form of EDM in which the conductive powder elements are added in the dielectric liquid to enhance machined surface characteristics and machining responses. The commonly used biomaterials such as 316L stainless steel, Ti-based alloy, Ni–Ti, Mg alloy, and Co–Mo–Cr alloy have excellent mechanical characteristics while the biofunction of these materials are not in satisfactory level. Due to higher hardness, brittleness, and heat resistant natures of the biomaterials, it is very challenging to machine them with conventional machining. Both the system efficiency and modified surface properties depend on the associated electrical and non-electrical factors of PM-EDM cycle. This review focuses on the influence of process factors such as current, pulse duration, tool-polarity, duty cycle, potential voltage, types of liquid, and added powder concentration on performance outputs including material removal and tool wear rate, coating thickness, coarseness, microhardness, coating adhesion bonding, biocompatibility, and resistant to corrosion. This study also discusses influence of various powders on machining and modified surface characteristics of biomaterials. The future research scopes and challenges of PM-EDM process are included in this study thoroughly.     

A review of ultrafine particles as antiwear additives and friction modifiers in lubricating oils

This paper gives an overview of developments in the use of ultrafine particles in lubricating oils to reduce wear and friction. Work on several types of particles, such as graphite, MoS₂, PTFE, BN, fullerene, and Cu, as well as more novel and unusual particles used as lubricant additives, is reviewed. The paper summarises the results of a number of workers in this field. The tribological mechanism by which ultrafine particles operate is considered, and some conclusions, including possible future directions for research, are drawn.     

碳纤维山地自行车架生产工艺的发展现状与发展趋势

碳纤维自行车架具有质量轻、强度高、刚度好、抗振性强等优点,是竞技山地车架发展的趋势。目前,碳纤维山地自行车架的生产多以RTM工艺为基础,国内外在设计和生产方面进行了大量创新,研究出诸如OCLV、IsoTruss、IsoGrid和ExoGrid以及ALMA、OIZ和Arantix等专利技术和产品,也暴露出了一些问题。未来几年,碳纤维山地自行车架的生产工艺在吸收、引进各种先进技术的同时,将有望进一步提高整体性能和降低生产成本。