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.     

连铸连轧生产线液压与润滑油监测的实践与探索

为提高钢铁冶金生产线的稳定性与可靠性,对广州珠江钢铁有限责任公司连铸连轧生产线液压与润滑油样理化性能、污染度、磨损颗粒进行了监测。通过监测可及时发现油液的劣化、污染和设备的磨损。由此保持系统较高的油品质量和清洁度,减少换油的次数与机器故障,改进了生产线的运行秩序并取得每年120万元以上的经济效益。     

始末速度不为零的S型加减速时间规划算法研究*

针对始末速度不为零的非对称S型加减速时间难以规划问题,把加速度曲线分为7个时间段,对关于加速度变化时间的方程组进行分析,化简为一元高次方程,并根据其变化的单调性构造其平方函数,使其转换为单一凸形函数,进而利用牛顿迭代求出其收敛值并根据效率最优原则和加速度、速度约束条件进行修正;对匀加速度时间的规划,直接根据其公式特点,转换为一元二次方程进行规划并根据效率最优原则和加速度、速度约束条件进行修正;对于匀速运动时间直接根据一元一次方程的解法进行规划。该算法解决了现有始末速度不为零的S型加减速时间规划过程复杂、繁琐问题,提供了一种简洁、高效的加减速时间规划算法。通过仿真与试验可知,本算法求解效率提高10.8%,插补效率提高1.32%,插补效果满足精度要求,同时证明了该算法简洁、高效、运行稳定、能够满足高速高精数控要求。     

缩口扩口复合成型工艺研究与应用

针对铁路车辆罐车零件锥管缩口、扩口的成型特点,用冲压成型缩口、扩口的力学分析及变形原理进行工艺计算与研究,找出该零件废品率高的原因。通过改进工艺毛坯（钢管）的外径与壁厚尺寸,用冲压成型缩口、扩口工艺理论及图表进行论证分析,并进行试制,取得了较好的效果。     

基于约束的复杂产品开发过程与活动路线分析

为实现在不同阶段、按不同层次和区域分析和控制产品开发微观过程的目的,提出一种基于“自组织-被组织”方法论规划和设计产品开发过程的方法。在面向过程的任务分层分解和基于约束的产品开发活动组织过程表达中,把与过程相关的约束和影响因素,通过节点间逻辑状态及其取值概率来反映和体现;应用图论中可达矩阵性质与原理定量分析产品开发活动序列及其组织路线,实现产品开发宏观过程管理和微观过程控制的有机结合,使产品开发活动的组织方式、状态演化和工作流程始终处于透明和可控的环境下观察和分析,帮助项目管理人员明确影响产品开发过程的主要路线和关键环节,克服传统方法综合多个要素、跨越整个过程建模和分析的困难。     

油管壁厚在线监测系统设计

在石油储运过程中,由于油管周围环境以及石油内某些化学物质的影响,油管内壁要受到不同因素的腐蚀和破坏,使壁厚变小,严重影响石油的运输。本文在综合评价各种管壁厚度监测系统及测试技术的基础上,确定了以超声波测试技术为基础,以计算机技术为核心的管壁厚度在线监测系统设计方案,详尽介绍了该系统各组成部分的硬件结构、工作原理,着重阐述了系统硬件设计。     

机械设计制造及其自动化发展方向解析

现代信息技术、科学技术的快速发展对机械设计制造领域也产生了深刻的影响,实现了机械设计制造的自动化发展,机械设备的性能得到提升,对人类社会生产发展提供了更多支持.为了能够更好的发挥出机械自动化对社会发展的作用,文章结合机械设计制造的内涵和发展意义,根据机械设计制造的特点和要求,就如何借助自动化技术来促进机械制造长远发展进...     

深海海底钻机收放系统动力学随机数值仿真方法研究

提出了一种随机不规则波浪激励下的收放系统动力学随机数值仿真方法。该方法以随机不规则波浪为输入,应用雨流计数法分析收放系统动态特性响应随机分布特征,获取不同水深和海况条件下收放系统动态响应统计规律。以深海海底钻机收放系统为例,对随机不规则波浪激励引起的母船摇荡-脐带缆-深海海底钻机摇荡进行分析,建立了计入海水阻尼的深海海底钻机收放系统动力学模型。然后,以随机不规则波浪的有义波高为特征值,产生随机不规则波浪激励,应用收放系统动力学模型分析计算系统动态随机响应,应用雨流计数法分析收放系统动态响应特性随机分布特征,并对不同水深和海况条件下的钻机摆动状况、升沉运动以及脐带缆张力等动态特性进行随机数值仿真分析与讨论。所提出的方法为随机不规则波浪激励下,海洋装备收放系统动态特性分析提供了新途径。     

核磁共振技术在岩石物理与孔隙结构表征中的应用

随着石油与天然气工业的勘探开发重点从常规储层转向非常规储层,全面认识非常规储层岩石物性和微观结构对实施高效的建产、增产、稳产措施具有重要的意义。面对油气储集空间多样化、流体在岩石多孔介质中渗流作用机理复杂化等问题,传统岩石物性测试和岩石静态微观结构描述已经不能满足油气渗流、储层增产的研究需要。核磁共振技术(NMR)具备无损、无害的特点,通过共振信号直接反映岩石孔隙流体分布和间接反映岩石孔隙结构变化,在岩石物理测试、孔隙结构表征和孔隙流体识别等方面具有突出优势。从方法基本原理出发,着重介绍了核磁共振技术在岩石物理学和孔隙结构表征领域的应用进展、归纳了应用中现存问题并展望了该项技术未来发展方向。     

可用作虚轴坐标测量机的全解耦并联机构运动学分析

针对提出的一平移两转动全解耦并联机构易产生奇异位置及工作空间较小等不足，通过改变支链两移动副的位置，得到了一种改进型全解耦性质、自由度及运动输出保持不变的一平移两转动并联机构；给出了其运动位置的正逆解析解，得到并分析了工作空间形状及大小；与原机构在正逆解数、解耦性与工作空间形状及大小等进行了比较，证实改进型机构为一种优选机型，更适合于用作虚轴坐标测量机、机床及其他运动平台的实用机型。     

Core-flood experiment for transport of reactive fluids in rocks

Investigation of the transport of reactive fluids in porous rocks is an intriguing but challenging task and relevant in several areas of science and engineering such as geology, hydrogeology, and petroleum engineering. We designed and constructed an experimental setup to investigate physical and chemical processes caused by the flow of reactive and volatile fluids such as supercritical CO(2) and/or H(2)S in geological formations. Potential applications are geological sequestration of CO(2) in the frame of carbon capture and storage and acid-gas injection for sulfur disposal and/or enhanced oil recovery. The present paper outlines the design criteria and the realization of reactive transport experiments on the laboratory scale. We focus on the spatial and time evolution of rock and fluid composition as a result of chemical rock fluid interaction and the coupling of chemistry and fluid flow in porous rocks.     

提高机械设计制造及其自动化的有效途径

随着我国科学技术水平的不断进步,制造行业也取得了非常大的发展,而机器设计制造及其自动化也有了很大的进步。机械设计制造及其自动化不仅具备传统工艺的特点,还结合了当代先进科学技术的优点。近些年来,我国机械制造制动化技术逐步取代了传统工业中较为落后的操作技术,对于提升企业的实际生产效率有着非常关键的作用。本文先是概述了机械制造及其自化的含义与特点,其次简述了机械设计制造及其自动化的优势与所需遵守的原则,然后分析了我国机械设计制造及其自动化的现状,最后探究了提高机械设计制造及其自动化水平的方法。     

游隙对滚滑轴承内部载荷及应力影响的研究

滚滑轴承是一种新型轴承,可应用于风力发电机齿轮箱。根据滚动轴承基本原理和接触力学原理,建立滚滑轴承有限元模型,研究滑块与内外套圈滚道之间的游隙对滚滑轴承内部载荷及应力的影响,得到不同游隙时不同大小载荷工况下典型工作位置处滚滑轴承的内部载荷与应力分布规律。在研究中,提出滚滑轴承临界载荷的概念。研究结论可以为滚滑轴承的基础理论研究和参数优化提供参考。     

气动轻量型机械臂伺服控制系统和碰撞检测方法研究

针对服务型机器人对系统的柔性、安全性提出的高要求,开展了气压驱动轻量型机械臂的伺服控制系统和碰撞检测方法研究。设计制作了二自由度轻量型机械臂样机,建立了机械臂的运动学和动力学方程,对系统的摩擦力矩进行了辨识。采用PID与加速度反馈和摩擦力前馈补偿控制策略,解决了机械臂关节旋转过程中的低速爬行问题。研究了基于被动柔顺控制和动力学方程的碰撞检测方法,实现了机械臂的防碰撞功能,提高了系统的安全性。通过对实验样机的试验测试,验证了机械臂的位置伺服控制策略和碰撞检测方法的有效性。     

理想材料零件的数字化设计制造方法及内涵

提出了理想材料零件的新概念 ,它是指按零件的最佳使用功能要求来设计 ,由呈梯度变化的组织成分和一定规律分布的细结构的材料与均质材料所组合构成的新型材料零件。提出并阐明了理想材料零件的数字化的并行设计制造 (简称数字化设计制造技术 )的方法和理论基础 ;它以材料与零件的一体化、集成化设计制造为主要特点 ,可根据零件功能要求进行零件的外部几何拓扑形状和内部材料组织细结构的并行设计 ,并采用增材制造和去材制造相结合的制造技术 ,按数字化设计的信息 ,一次完成零件内部组织结构和三维形体的制造。指出数字化设计制造将会使人们长期以来设想的按力学、电磁学性能来高效地设计制造新材料零件变为现实 ,在不远的将来定能像设计和建造房屋那样 ,按照所需功能设计制造理想材料零件。     

起重机金属结构的接地检验

在起重机安装和检验过程中,经常存在金属结构接地不规范和检验尺度不统一。为了澄清接地的概念,避免因接地不当造成的起重机安全事故,本文分析了低压配电系统三类接地方式的特点及其应用情况,阐述了保护接地和保护接零的工作原理,纠正了保护接零和重复接地的概念及其适用场合,提供了一些起重机金属结构接地检验的技巧和检验中需要注意的内容,为起重机安装和检验提供有益的参考。     

Friction and wear characteristics of organic thiophosphoro derivatives — a critical appraisal

The friction- and wear-reducing characteristics of a number of oil soluble sulphurised and phosphosulphurised derivatives for automotive and industrial applications have been reviewed. A critical appraisal of the suggested causes and mechanism of friction reduction and antiwear characteristics has been made. A review of the investigations carried out so far indicates that the creation of in situ films of simple inorganic salts, such as molybdenum disulphide, iron sulphide or phosphates of low shear strength and lamellar structures, does not appear to be the primary cause of low friction and wear. The authors have, therefore, undertaken a programme to synthesise and study the chemistry and tribochemical reactions in relation to friction and wear characteristics of hydrocarbon-soluble thiophosphoro derivatives of alkyl phenol, alcohols and fatty esters, in order to establish relationships between the reactivity, chemical nature and crystal structure of films formed on rubbing surfaces, and antifriction and antiwear characteristics. Molybdenum salts of various phosphorothio derivatives of pentadecylphenol and lauryl oleate of specific structures have been synthesised, and the friction and wear properties of their blends in mineral oil base stock have been studied. It can be clearly inferred from the results that type of bonding between sulphur, phosphorus and molybdenum, and reactivity of these derivatives with rubbing surfaces, determine their friction-reducing and antiwear characteristics. Their reactivity with iron and the nature of films formed are under investigation.     

学习的永恒维度与永恒评价指标

当代人以知识与技能为中心维度看学习、评价学习结果,将知识与技能以外其它智能与品质置于从属位置。《论语》“学而”篇第七章构造出人伦四大支柱,以人伦四大支柱为中心维度看学习、评价学习结果。以知识与技能为中心维度看学习、评价学习结果,是对学习本质的严重矮化;以人伦四大支柱为中心维度看学习、评价学习结果,才标出学习本质的应然高度,才指明学习的应然本质。从世界教育认识体系中纵向与横向地看,中国儒家对学习的认识具有超越时代、超越空间的普适性意义,人伦四大支柱是学习的永恒维度与永恒评价指标。     

Test procedure of cladded alloys for resistance against high temperature abrasive wear

This article discusses the development of procedure and assembly for testing metals and alloys for abrasive wear at ambient and higher temperatures of up to 600°C. The procedure can be applied both to evaluate the operating properties of alloys used to clad of machine parts and tools of metallurgical and refractory purposes, and to test various metal and composite materials. The wear of alloys as a function of temperature, the pressure on specimen, and its shape, as well as of the composition and dispersity of abrasive mass have been determined. Hardness and wear resistance of some experimental and commercial alloys have been presented, and the influence of alloy doping and modifying on their wear resistance at higher temperatures has been established.     

Technical state space of unique mechanical systems

The dynamics of technical states of unique mechanical systems is given in the form of a model consisting of mutually conditioned and interacting elements reflecting continuous and discrete degradation processes. The model elements representing each state and process are a formalization of knowledge and are characterized by a structure and a set of properties and parameters. This ensures efficient use of information technologies and artificial intelligence methods and facilities for the investigation and substantiation of properties and parameters characterizing a technical state, causing its change, and enabling predictions.