带压密封技术规范讲座——泄漏与密封

本次讲座介绍泄漏的分类、危害及密封方法分类简介等. 泄漏所发生的部位是相当广泛的,几乎涉及所有的流体输送与储存的物体上.泄漏的形式及种类也是多种多样的,而按照人们的习惯称呼多是漏气、漏汽、漏风、漏水、漏油、漏酸、漏碱、漏盐;法兰漏、阀门漏、油箱漏、水箱漏、管道漏、弯头漏、三通漏、四通漏、变径漏、填料漏、螺纹漏、焊缝漏、丝头漏、轴封漏、反应器漏、塔器漏、换热器漏、暖气漏、船漏、车漏、管漏、坝漏、屋漏等等.但流体生产工业中对泄漏术语则有其特定的含义.     

由底盘技术发展看刃具发展前景

引进国内外刀具的使用情况1.底盘厂目前使用国外刀、辅具的情况底盘厂加工中心上所选用刀辅具的国外厂商有:SandvikCormant、Kennametal、WidiaValenite、Iscar、Guhring、Seco、Walter、Titexplus、Beck、Bass、Kyocera、住友、Nikken、Plansee。所选用刀、辅具的种类有:铣刀、车刀、镗刀、锪刀、铰刀、钻头、丝锥、倒角刀及各种刀柄等。这些刀、辅具基本上能够代表着目前     

ICP-OES测定化探样品中21种元素谱线的选择

对采用ICP-OES法测定化探样品中Al、Ca、Fe、Mg、Na、K、Cr、Ti、Nb、V、Be、Co、Ni、Cu、La、Li、Ba、Mn、P、Sr、Zn等21种元素时谱线的选择进行了研究,在充分考虑了各元素的谱线干扰特点、背景校正的合理位置、曲线拟合的线性关系、谱线的强度大小、待测元素的含量范围、能否有效扣除谱线背景干扰和峰形的对称程度的因素后确定21种元素的分析谱线。用选定的分析谱线测得的21种元素的精密度(RSD)均小于5.8%,并且方法检出限低,满足地球化探样品分析的要求。     

《现代科学仪器》期刊简介——中国科技核心期刊、RCCSE中国核心学术期刊

科研工作者,购置仪器的管理人员,大专院校和科研院所的师生,企事业单位的技术工程师等。涉及医疗卫生、制药、农业、地矿、机械、电子、石油、化工、冶金、能源、交通、环保、建筑、轻工、商检、技术监督等领域。     

3WZK-15型框架式喷雾机

3WZK-15型框架式喷雾机广泛适用于市政、园林、绿化带、草坪、苗圃、棚架作物、温室、花木果树的病虫害防治;武装部队战地、训练场地、野营宿舍、水灾、震灾地区的卫生防疫、消毒;车站、医院、宾馆、泳池、废物处理场、屠宰场、水产交易场、粮库、动物园等场所的清洗、消毒。具有作业效率高、使用灵活、操作简单等优点。     

环保型高性能半合成切削液的研制与应用

通过筛选性能优良的基础油、润滑剂、防锈防腐蚀剂、乳化剂、硬水稳定剂等添加剂,研制出不含矿物油、硫、磷、氯、硼、苯酚、甲醛、仲胺、重金属、亚硝酸钠等有毒有害物质的环保型半合成切削液。性能测试表明,研制的半合成切削液具有优异的理化性能、稳定性、润滑性和防锈防腐蚀性。实际应用表明,研制的半合成切削液能用于难加工材料如高温合金钢、镍合金、钛合金以及各种铝合金的车、镗、铣、钻、攻丝、拉削、攻螺纹等多种切削加工,可延长刀具寿命,提高加工效率。     

我国紧固件产品质量状况综述

紧固件是一种公认的量大面广的通用基础件，包括螺栓、螺钉、螺柱、螺母、自攻螺钉、木螺钉、垫圈、挡圈、销、铆钉、连接副和组合件及其他12大类，广泛用于机床、通用机械、汽车、拖拉机、农业机械、工程机械、电力工程、发电及输变电设备、石油化工、桥梁、轨道车辆、军用车辆、冶金机械、重型、矿     

《现代科学仪器》征稿启事

《现代科学仪器》是在国家有关领导人和著名科学家的指导和大力支持下诞生的。它是中国科技核心期刊,是国内最重要的以介绍和评论国内外仪器为主的综合性科技期刊。读者对象为各行各业实验室、试验室、研究室应用与维护仪器的科技人员及购置与管理仪器设备的人员;从事高技术及其产品研制生产的科技人员;各级有关管理决策人员;大专院校师生等。涉及物理、化学、生物、医疗卫生、制药、农业、地矿、机械、电子、石油、化工、冶金、能源、交通、环保、建筑、轻工、商检、     

《振动、测试与诊断》征稿简则

一、刊登内容有关振动利用、动态测试和故障诊断的标准、测试理论、测试手段的论文和专题报告,包括实验测试技术、测试仪器的研制方法、系统组成、信号分析、数据处理、参数识别、故障诊断以及有关装置的设计、使用、控制、标定和校准等。不拘泥于行业(如机械、交通、农业、生物、能源、航空、航天、航海、建筑、地震等)和测试项目(如振动、冲击、力位移和噪声等)。     

《振动、测试与诊断》征稿简则

一、刊登内容有关振动利用、动态测试和故障诊断的标准、测试理论、测试手段的论文和专题报告,包括实验测试技术、测试仪器的研制方法、系统组成、信号分析、数据处理、参数识别、故障诊断以及有关装置的设计、使用、控制、标定和校准等。不拘泥于行业(如机械、交通、农业、生物、能源、航空、航天、航海、建筑、地震等)和测试项目(如振动、冲击、力位移和噪声等)。     

Fixed-point and stratified analysis of the fine structure and composition of five gallstones with Fourier transform infrared (FT-IR) specular reflection spectroscopy

By investigating the identities, amounts, and distributions of the major components of human gallstones, the formation mechanism of calculi may be elucidated. Using FT-IR specular reflection spectroscopy, the compositions of five common types of gallstones, including cholesterol calculus, bile pigment calculus, cholesterol-bilirubin calculus, mixed calculus, and black stones, were positionally, qualitatively, and quantitatively analyzed. Several organic and inorganic substances were found in human gallstones, including cholesterol, calcium bilirubinate, calcium carbonate, calcium phosphate, and calcium stearate. Among them, cholesterol and calcium bilirubinate were the main components. The amounts of these substances varied in different types of gallstone. The distributions of cholesterol and calcium salts (with the exception of calcium bilirubinate) were also closely associated with location. In the various calculi, the amounts of cholesterol and calcium bilirubinate in the cores, the layered structures outside the cores, and the outer shells were higher than those of other substances. The identities of the major components of calculi were similar in different types of gallstones, but their amounts and distributions were significantly different. The analytical method used in this study, which was able to accurately determine the location, quality, and quantity of the major components of gallstones, would be an effective tool to study the formation mechanism of calculi.     

ICP-MS顺次分析鸡蛋壳中微量元素

本研究基于顺次电离质谱分析技术,发展了一种直接质谱分析方法分析鸡蛋蛋壳中微量元素。在仅需少量样品预处理的条件下,分别用水和5%稀硝酸作为洗脱液,对鸡蛋壳中水溶性微量元素组分和酸溶性微量元素组分进行顺次提取,然后在线传输至ICP-MS进行分析。该方法可在10 min内实现单个样品中15种微量元素水溶性组分和酸溶性组分的顺次分析,具有仅需少量样品预处理、分析速度快、样品消耗量小等优点。采用顺次电离质谱分析方法考察了赣州土鸡蛋、赣州营养鸡蛋、赣州草鸡蛋、毛庵村毛氏土鸡蛋、吉安泰和土鸡蛋的蛋壳小头、中部和大头3个部位上15种微量元素的水溶性和酸溶性组分信息。结果表明,鸡蛋蛋壳上微量元素的含量、形态和分布可构成一个完整的“指纹谱”,不同种类鸡蛋壳的微量元素“指纹谱”具有显著区别,该“指纹谱”在鉴别鸡蛋种类、判定鸡蛋质量方面具有潜在的应用价值。     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

Effects of polydatin on the proliferation,migration, and invasion of ovarian cancer

To investigate the effects of polydatin on the proliferation, migration, and invasion of ovarian cancer, the change of proliferative ability, migration ability, and invasive ability of human ovarian cancer cell OVCAR-3, A2780, and HO-8910 was detected by using polydatin and up-regulating PI3K. The anticancer activity and mechanism of polydatin in ovarian cancer were analyzed. Polydatin could effectively inhibit the proliferation, migration, and invasion of OVCAR-3, A2780, and HO-8910, and inhibit the expression of PI3K protein. After the expression level of PI3K protein was up-regulated, the inhibitory effect of polydatin on the proliferative ability, migration ability, and invasive ability of OVCAR-3, A2780, and HO-8910 significantly decreased, suggesting that PI3K was the target of polydatin. Therefore, we concluded that polydatin could inhibit the proliferation, migration, and invasion of ovarian cancer cells by inhibiting the expression of PI3K protein, which provides an experimental basis for polydatin in the treatment of ovarian cancer.     

智能机床发展现状与技术体系框架

智能机床成为机床装备发展的趋势。在介绍国内外智能机床的研究现状的基础上,分析目前智能机床技术研究的三个问题,提出智能机床的狭义和广义定义;给出智能机床的包括人计机的协同性、整体与局部的协调性、智能的恰当性与无止性、自学习及其能力持续提高性、自治与集中的统一性、结构的开放性和可扩展性、制造和加工的绿色性、智能的贯穿性八个智能技术特征;阐述包括以人为中心的人计机动态交互功能、三个基本功能——执行智能功能、准备智能功能、维护智能功能的智能功能特征,以及功能之间的相互关系;建立八个理论与技术的智能机床技术理论框架,包括人计机一体化融合理论与技术、多源信息的感知理论与技术、智能决策理论与技术、智能执行理论与技术、智能维护理论与技术、智能机床综合能力评价理论与技术、智能机床标准化技术、智能机床支撑技术等,形成了智能机床的技术体系框架,同时指出上述内容将随着技术的进步和应用的深入不断充实和丰富。     

Distribution curves of sectional areas through some families of convex particles

We outline the results of a computer program which calculates frequency distributions of functions of cross-sectional regions of convex planar-faced polyhedra, ‘sphero-polyhedra’, and populations of perturbed polyhedra. This is done by ‘cutting’ a computer representation of the figure by a large number of random planes. The procedure is applied to cubes, dodecahedra, truncated octahedra, and approximate β-tetrakaidecahedra. Certain aspects of the shape of the object, e.g. sharpness of corners, angularity, compactness, and degree of symmetry are related to aspects of the shape of the distribution curves, e.g. beginning and ending points of the curves, rate of rise of the peak, relative location of the peak, and height and width of the peak.     

Discussion on advanced manufacturing

Advanced manufacturing consists of continuity of manufacturing, its broad sense, and the core of the manufacturing process. The technology of continuous manufacturing is discussed according to both historical and modern perspectives. The relationship between human development and manufacturing technology is also discussed. Manufacturing is a continuously evolving topic. It is not only the foundation and means of imagination, conception, the science, and the technology of material change, but also the expression of national economy, national defense, and the support industries. The broad sense of manufacturing theory, which extends the concept of manufacturing, is an important development in the 20th century. The sense is analyzed in connection with design, material forming theory, synthesis of manufacturing technology, manufacturing modes, life cycle of product, hardware and software, and support environment, etc. At the same time, the core action and the development of the theory and technology of process is also discussed. At the end of this paper, the development directions of mechanical manufacturing science and technology are mentioned.     

A review of studies on estimating the discharge coefficient of flow control structures based on the soft computing models

The discharge coefficient (Cd) plays a vital role in the accurate design and safety of weirs, spillways, and dams. In the last decade, Soft Computing(SC) models, which showed excellent capabilities for non-linear mapping between parameters, were widely used to estimate the discharge coefficient of flow control structures. This study provides a comprehensive review of the application of SC models for estimating Cd of different flow control structures such as ogee spillways, orifices, side weirs, etc. In addition, the most common empirical relations which are obtained from laboratory experiments are discussed briefly. The findings revealed that weir length/flow depth ratio, weir length/channel width ratio, weir height/flow depth, and Froude number are widely used to estimate Cd in the side weirs. Besides, the ratio of orifice crest height to height of side orifice, the ratio of main channel width to length of side orifice, ratio of main channel width to height of side orifice, and ratio of the height of side orifice to upstream flow depth were extensively employed to calculate Cd of orifice structures. The common parameters for measuring Cd of labyrinth weirs are, discharge over a labyrinth cycle, weir height, channel width, apex constant, upstream head, discharge over the weir, effective length, convergence constant, sidewall angle, and Froude number. In the weir-gate structure, some factors such as contraction coefficient of the gate, head loss, and weir height are key parameters for the accurate evaluation of Cd. The trends of SC models, features of popular models, and the background of models are discussed briefly in this paper. Also, research gaps and possible directions for new studies are suggested.     

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。     

Influence of Certain Vapors and Liquids on the Frictional Properties of Molybdenum Disulfide

The influence of certain vapors and liquids on the coefficient of friction of molybdenum disulfide has been studied under boundary conditions. The vapors investigated were those of water, butanol, benzene, and heptane. The liquids used were water, glycol, glycerol, dodecanol, dodecylamine, dodecane, hexadecane, ocladecane, white paraffin oil with and without additions of nonanoic acid and nonyl alcohol, and commercial mineral oil. The tests were performed on various friction testing machines, viz., on the LFW-1, LFW-2, Almen-Wieland, and Reichert machines. The test results show that the coefficient of friction of molybdenum disulfide is lowest in absence of the vapors or liquids studied, and under these conditions is independent of load. With increasing polarity of the vapor or liquid the coefficient of friction of molybdenum disulfide increases.