多路信号采集及显示实验仪器设计

研究了基于MAX114多路信号采集及显示实验仪器系统的实现方案、组成结构及软件设计。应用单片机控制AD转换器件及液晶显示模块实现了对多种传感器的数据采集及信号测量,可简单实现对多种传感器信号的采集与处理;为传感器信号测量提供了一个平台。该实验仪器可以对4路模拟信号进行采样,采样精度为8位,转换速率可达1MSPS;同时该实验仪器具有对4路传感器模拟信号进行加工处理并具有液晶实时显示的功能。     

RGA10质谱计的改进及在K-Ar、Ar-Ar同位素定年中的应用

对 RGA1 0质谱计离子源、分析室、样品提纯系统及数据处理系统等方面进行了改进 ,并增加了 3 8Ar大小球分取装置 ,使该仪器灵敏度、真空度及仪器的综合指标比过去有了较大改善 ,仪器的稳定性及测试样品的速度有了很大提高。仪器改造后三年来的实验证明 :Ar同位素的分析效率提高了 2至 3倍。     

图像分析仪在粉体颗粒测试上的应用

介绍了一种功能强大的测试粉体颗粒形貌特征的仪器——图像分析仪。并探索了测试粉煤灰或相似粒径粉体的实验方法及一些仪器参数的确定。     

叶绿素监测仪器在水质自动监测应用中的优劣浅析

叙述了叶绿素在线自动监测仪器的工作原理及实验结果，肯定了该仪器在海水水质在线自动监测中的作用，并分析了该仪器在应用上相对于实验室方法的优缺点。     

IR-200A型红外测油仪的调试

根据红外测油仪测定水中矿物油的工作原理,在IR-200A型红外测油仪的调试过程中,给出了仪器的检出限、精密度、准确度,不同型仪器比对实验结果,校正系数测定结果及实际样品加标回收试验结果.实验表明,该仪器能够满足测定项目的要求.     

压力计测试系统的设计

介绍一种井下压力计测试系统组成及工作原理,结合软硬件结合的技术特点,阐述了井下仪器的软硬件设计、地面回放软件设计,并给出了实验测试及分析建议.该仪器适用于油、水井生产测井及试井.     

医学实验室分析仪器教学的探讨

在教学经费有限，实验仪器不足，仪器不断发展变化的情况下，为了提高检验仪器学实验教学的质量，作者就其教学途径进行了探索，经过多年实践，总结出以下经验；充分发挥检验系实验室现有分析仪器的作用；开设分析仪器模拟实验及分析仪器整形机分部化实验；利用本校、附近医院和分析仪器厂家的仪器进行示范教学；逐步引进虚拟现实技术。     

逾渗教学演示实验开发

介绍基于逾渗原理的演示实验开发,该实验主要使用自行研发的逾渗演示实验仪器进行实验操作,该实验仪器操作简便,通过使用发光二极管、导体球、电流表等主要元素能让学生更好的理解逾渗的形成过程及基本原理,此外还能提高学生的动手能力及团结协作意识,同时也为教育教学以及该领域理论的普及起到了积极的推动作用。该实验可用在中高等院校的教学演示实训项目。     

石油测井仪器可靠性快速评价方法

本文根据可靠性强化实验原理，提出了快速评价石油测井仪器可靠性的工作流程和实验方法。该方法先要确定石油测井仪器的可靠性控制点和极限工作条件，进而通过对可靠性控制点的局部评价，实现仪器整机可靠性的快速评价。在多种型号的自然伽玛测井仪设计和生产中应用了该方法，结果表明，设计阶段对关键部件的单一工作条件实验，能够实现仪器可靠性设计的快速评价；生产阶段对整机的综合工作条件实验，能够实现仪器整机可靠性的快速评价。该方法在实现石油测井仪器可靠性快速评价的同时，能够减少实验次数，缩短仪器设计和生产周期。     

自动阿贝折射仪的研究

提出了基于光的全反射原理,利用单色发光二极管作为光源和线阵CCD作为传感器,结合计算机图像处理技术,实现了WYA-Z自动阿贝折射仪的设计。并简要介绍了仪器的工作原理、光路系统、仪器组成、关键技术、设计要求及实验验证。实验结果表明:仪器的折射率测量范围:1.3000～1.7000,精度n_D:±0.0002,重复性n_D:±0.0001。该仪器不仅能自动测量液体的折射率,还能自动测量液体的浓度,因此具有广阔的市场前景。     

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.     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.     

Mass spectrometry analysis of the influenza virus

The role of mass spectrometry to probe characteristics of the influenza virus, and vaccine and antiviral drugs that target the virus, are reviewed. Genetic and proteomic approaches have been applied which incorporate high resolution mass spectrometry and mass mapping to genotype the virus and establish its evolution in terms of the primary structure of the surface protein antigens. A mass spectrometric immunoassay has been developed and applied to assess the structure and antigenicity of the virus in terms of the hemagglutinin antigen. The quantitation of the hemagglutinin antigen in vaccine preparations has also been conducted that is of importance to their efficacy. Finally, the characterization and quantitation of antiviral drugs against the virus, and their metabolites, have been monitored in blood, serum, and urine. The combined approaches demonstrate the strengths of modern mass spectrometric methods for the characterization of this killer virus. [This article was published online 10 September 2008. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 7 November 2008.]     

软体足式机器人驱动、建模与仿真研究综述

软体足式机器人因其优越的移动性能及面对复杂地形的通过能力受到越来越多研究者的关注。由于受到材料性质、驱动方法及制造工艺等多方面的限制,如何实现软体足式机器人的创新结构设计,提升软体机器人的运动速度和负载能力是目前亟待解决的问题之一。综述从仿生结构与驱动方法的角度对目前软体足式机器人的研究发展进行了系统阐述。由于软体机器人多为连续变形结构,加之软材料的物理非线性和软结构变形的几何非线性,力学建模与仿真一直是软体机器人研究领域的瓶颈。梳理了目前软体机器人的主要建模理论,总结了软体机械臂的建模与控制方法,进一步将其拓展到软体足式机器人的系统建模中。介绍了传统商业软件的应用与物理仿真引擎开发的进展,分析了软体机器人虚拟仿真的主要方法,展望了软体足式机器人的应用场景与未来研究方向。     

DESIGN AND ANALYSIS OF NOVEL ACTIVE ACTUATOR TO CONTROL LOW FREQUENCY VIBRATIONS OF SHAFT SYSTEM

Aiming at providing with high-load capability in active vibration control of large-scale rotor system, a new type of active actuator to simultaneously reduce the dangers of low frequency flexural and torsional vibrations is designed. The actuator employs electro-hydraulic system and can provide a high and circumferential load. To initialize new research, the characteristics of various kinds of active actuators to control rotor shaft vibration are briefly introduced. The purpose of this paper is to introduce the preliminary results via presenting the structure, functions and operating principles, in particular, the working process of the electro-hydraulic system of the new actuator which includes a set of high speed electromagnetic valves and a series of sloping cone-shaped openings, and presenting the transmission relationships among the control parameters from control signals into the valves to active load onto shaft. The course of the work is dynamic, and a series of spatial forces and moments are put on the shaft to get an external resultant force to reduce excitations that induce vibration of shafts. By checking states of vibration, the actuator can control the impulse width and the interval of injection time for applying different control force to a vibration shaft in two circumference directions through the regulating action of a set of combination directional control valves. The results from simulating analysis and experiment show evidence of that this design can satisfy the case of active process of decreasing of flexural and torsional vibrations.     

不同因素对汽车传动离合器接合过程影响分析

离合器是汽车传动系统的重要组成部分,其接合过程直接影响到车辆起步性能和动力传递,并影响系统各单元的使用寿命.针对离合器接合过程的特点,对滑摩状态和接合状态进行动力学分析,建立系统的动力学模型;从滑摩功和冲击度两个方面对离合器接合过程进行评价,获取影响换挡品质的评价指标因素;根据动力模型和数学模型,基于Simulink建...     

The effect of basic nitrogen compounds on the tribological performance of sulphurised olefin

The effect of the molecular structure of basic nitrogen compounds on the lubricating properties of sulphurised olefin has been investigated using a Timken tester. X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Analysis (EDAX) were used to study the chemical states of sulphur and nitrogen on the rubbed surfaces and the reaction rates of sulphur and iron separately. It was found that the antiwear and friction reduction properties of sulphurised olefin are greatly influenced by the different molecular structures of the basic nitrogen compounds. A composite additive package containing basic nitrogen compounds with sulphurised olefin can produce either synergistic or antagonistic effects, due to the influence of the different molecular structures of the basic nitrogen compounds. XPS analysis revealed that a tribochemical protective film containing nitrogen and sulphur was formed on the rubbed surface. EDAX analysis indicated that the reaction rates between elemental sulphur and iron were influenced by the different molecular structures of the basic nitrogen compounds. It was found that the apparent reaction rates of elemental sulphur and iron are related to the tribological characteristics of the additive package.     

一种高精度求解多轴机器人逆运动学的方法

提升多轴机器人逆运动学的求解精度与速度是保证机器人轨迹规划与实时控制性能的基础，也是机器人领域密切关注的难题。提出一种高精度、高效率地求解3至6R串链机器人逆运动学的方法。首先，将用于描述机器人位置与姿态的旋转变换阵与单位四元数采用半角正切的形式表达，建立与关节角度无冗余的机器人位姿方程。其次，分析Dixon结式求解多元高阶多项式的方法，将其应用于求取3R与一般6R机器人的逆运动学解析解。利用多项式环的特性处理矩阵，能够有效避免计算奇异性的产生。通过分析以矢量表达的Dixon矩阵，消去矩阵中的一些无效项，降低矩阵的阶数，避免阶次组合爆炸问题的发生。仿真实例表明，任意可达姿态下，6R机器人的逆运动学解一般能达到8组，这一多解的性能提升机器人的灵巧度。一般6R机器人逆解的单次计算时间不高于4ms，位置及姿态误差(相对)均小于10^-15，验证所提出的逆解方法的实时性和精密性。本文所做工作为精密操作机器人的运动学研究提供了理论依据。     

基于刚柔耦合的高方平筛动力学建模与振动模态分析

针对高方平筛和其上固结的柔性吊杆组成的动力学系统,进行了刚柔耦合的动力学建模和振动模态分析。将筛体—偏重块系统和吊杆分别作为刚体和弹性的可变形体,建立了筛体稳态圆振动方程和吊杆悬臂梁力学模型,总结出系统固有频率的计算方法。在此基础上,采用有限元方法对系统进行了模态计算和动力学响应分析。结果表明,理论模型能够很好地反映筛体与吊杆之间的动力学耦合关系;以理论分析为基础的载荷和边界条件的设置,使有限元仿真结果较准确地模拟了系统实际的振动特性。     

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

The multitooth meshing state of harmonic drive (HD) is an important basic characteristic of its high transformation precision and high bearing capacity. Meshing force distribution affects the load sharing of the tooth during meshing, and theoretical research remains insufficient at present. To calculate the spatial distributed meshing forces and loading backlashes along the axial direction, an iterative algorithm and finite element model (FEM) is proposed to investigate the meshing state under varied transmission loading. The displacement formulae of meshing point under tangential force are derived according to the torsion of the flexspline cylinder and the bending of the tooth. Based on the relationship of meshing forces and circumferential displacements, meshing forces and loading backlashes in three cross-sections are calculated with the algorithm under gradually increased rotation angles of circular spline, and the results are compared with FEM. Owing to the taper deformation of the cup-shaped flexspline, the smallest initial backlash and the earliest meshing point appear in the front cross-section far from the cup bottom, and then the teeth in the middle cross-section of the tooth rim enter the meshing and carry most of the loading. Theoretical and numerical research show that the flexibility is quite different for varied meshing points and tangential force amplitude because of the change of contact status between the flexspline and the wave generator. The meshing forces and torsional stiffness of the HD are nonlinear with the torsional angle.