激光粒度测量计

1 引言 在许多工业中都需进行物料细磨,为了控制细磨工艺过程,和鉴定细磨物料质量(粉料内颗粒配比,比表面积和颗粒形状)都需要有一种高效粒度测量计。 传统的粒度测量采用筛分方法,在某些生产工艺中采用筛分方法是足够的,而对于另一些工艺过程粒度测量还需沉淀和测微显微镜进行配合。目前已有一种方便、小巧、高效的筛分机,它装有可调节的振荡频率和振幅的电磁振荡来代替机械振荡装     

超细磷酸钙粒度测定的方法研究

探讨了在用激光粒度分析仪测定超细磷酸钙粒度过程中，不同测试条件对超细磷酸钙粒度测试结果的影响。实验结果表明：当泵速为2200转／分，超声强度为10，超声时间为2min，加0。1g／mL六偏磷酸钠为分散剂时．即为测试超细磷酸钙粒度的最佳分散条件。     

如何判断和选择激光粒度分析仪

以往的粒度分析方法通常采用筛分或沉降法。常用的沉降法存在着检测速度慢 (尤其对小粒子 )、重复性差、对非球型粒子误差大、不适用于混合物料 (即粒子比重必须一致才能较准确 )、动态范围窄等缺点。随着激光衍射法的发明 ,粒度测量完全克服了沉降法所带来的弊端 ,大大减轻了劳动强度及加快了样品检测速度 (从半小时缩短到了 1分钟 )。激光衍射法测量粒度大小基于以下事实 :即小粒子对激光的散射角大 ,大粒子对激光的散射角小。通过散射角的大小测量即可换算出粒子大小。其依据的光学理论为米氏理论和弗朗霍夫理论。其中弗朗霍夫理论为大颗…     

国内外激光粒度仪结构与性能介绍

依据激光粒度仪的原理,分析国内外激光粒度仪的光学结构与性能特点,探讨了激光粒度仪的发展方向。     

超声衰减粒度仪在煤粉粒度测量中的应用

煤粉的粒度分布是影响煤粉所成物质的物理性质。然而对水煤浆煤粉粒度的测定,是个值得探讨的问题。本文介绍了超声衰减粒度仪测量原理,对比了激光粒度仪和超声衰减粒度仪的特点,并且通过实验说明超声衰减粒度仪在煤粉粒度测定中应用的优势。     

马尔文激光粒度分析技术在油田碎屑岩油藏注水水质分析中的应用及优势

水在石油开采中占有极其重要的地位。当油从地下排出时总是以一种油在水中的乳浊液形式出现的。经油水分离过滤后 ,用高压重新注入地下 ,以使珍贵的原油从岩石隙中开采出来。但如果水中带有大量悬浮物 ,它们就会阻塞注水井渗滤端面及渗流孔道而阻碍油的采出。所以 ,对油藏注水水质有严格的要求和标准。以往 ,各采油厂对水中悬浮颗粒的测定都采用的是计数器法 ,但该方法操作烦琐 ,需配电解液、超滤 ,并对仪器用标准粒子校正 ;需更换不同的孔管分段测量以获得粒度分布图 ;很难得到 1 μｍ以下的粒度分布数据。我们采用英国马尔文公司的激光粒…     

马尔文激光粒度分析仪测定高抗冲聚苯乙烯中橡胶粒度的分布

本文利用Malvern Mastersizer 2000激光粒度分析仪分析了,高抗冲聚苯乙烯(HIPS)产品分别以丁酮和甲苯做为分散剂,考察了数量平均粒径D(1,0)、表面积平均粒径D(3,2)、体积平均粒径D(4,3)的重复性和相对标准偏差.说明了该方法容易建立,精密度高,非常适合生产过程中的分析.     

激光粒度分析仪的数值计算

在介绍了激光粒度分析仪基本原理的同时，对光电探测器上的光能分布公式作了详细分析，提出了一种改进的计算光电探测器上能量的数值方法。并通过实际计算证明，这种方法能够改善颗粒尺寸分布的求解精度。     

用激光粒度仪考察介质对氢氧化铝粒度的影响

氢氧化铝是制备氧化铝的中间产物,控制它的粒度及其分布情况对于生产起到至关重要的作用。本实验采用不同的分散介质,考察其对粒度的影响,为测定氢氧化铝粒度提供一些数据和参考条件。     

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.     

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.     

MODELING METHOD FOR PRODUCT STRUCTURE MAPPING BASED ON REVERSE SOLVING OF LOCUS AND MOTION

Aiming at the problem of structure design in reverse-design of mechanism, a structure mapping method based on reverse solving of locus and motion (RSLM) is presented. The mechanism scheme meeting the requirements of geometric and structural features is obtained through RSLM. The element instance subsets related to component are established based on the element type mapping, pair structure type mapping and design knowledge mapping between components and elements layer by layer. The assembly position mapping of elements is established based on the topological structure information of mechanism scheme, and the product modeling of structure mapping is realized. The algorithm program and prototype system of product structure mapping based on RSLM are developed. Application samples show that the method implements the integration of scheme design, assembly design and structure design, and modeling for product structure mapping based on RSLM. The feasibility of assembly is analyzed in scheme design that contributes to reducing the design error, and raising the design efficiency and quality.     

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.]     

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.     

45钢电子束扫描相变硬化组织和硬度的研究

电子束表面处理可以提高钢铁材料的表面硬度和力学性能。研究电子束扫描对45钢硬化层组织和性能的影响,探讨电子束功率、扫描速度等工艺参数对硬化层组织和性能的影响。采用扫描电镜分析45钢电子束表面强化层的显微组织,用显微硬度计进行硬度测试。结果表明,45钢经电子束扫描处理后,硬化层的组织为针状和板条状马氏体,组织比常规调质处理更加均匀、细小,试样表面的平均硬度达58 HRC,比淬火加低温回火处理的硬度高3～5 HRC,是调质处理的两倍,从处理表面往下沿深度方向硬度逐渐减小。电子束工艺参数对硬化层组织和性能有较大影响,硬化层宽度和深度随着电子束功率的增加而增加,随着扫描速度的增加而减小;硬化层的最高硬度随着电子束功率密度的增加而增加,随着扫描速度的增加而减小。     

连杆的稳定承载能力有限元计算

利用有限元分析软件ANsYS10.0,对外形及其受力都比较复杂的内燃机连杆稳定承载能力进行了较为精确的线性及非线性分析.得出了连杆弹性屈曲时的屈曲模态ω(x)=Asin（nπx）/l前4阶屈曲模态及非弹性屈曲时稳定临界载荷.为工程实践中外形和受力复杂的受压杆件稳定承载能力的精确分析计算提供了可行、有效的方法和分析数据.     

一种角位移电涡流传感器的原理及应用

设计并实现了一种小角度双E形电涡流角位移传感器，可用于加速度计及陀螺仪闭环控制的校正回路。运用涡流等效原理，从理论和计算上分析了其原理，分析了其反力矩的形成，推导了电涡流传感器的输出方程。对该传感器的输出特性和频率响应特性的实验结果作了分析，结果表明了其可行性，对设计和应用同类传感器有一定的指导意义。     

增压器涡轮叶片疲劳蠕变寿命预测方法

根据径流式增压器涡轮的结构与工作特点,分析了涡轮叶片的载荷与应力空间分布特征;针对增压器涡轮由疲劳与蠕变交互作用引起的叶根断裂失效模式,研究了增压器涡轮叶片叶根的载荷与应力变化历程,建立了涡轮叶片叶根的载荷与应力描述方法;然后建立了增压器涡轮叶片叶根疲劳蠕变寿命预测方法及模型,并运用建立的模型对增压器涡轮叶片叶根进行了寿命评估。     

电机群网络管控一体化PLC-SCADA设计及应用

针对电机数量众多、时序复杂、传动要求高、地域分布分散等工业生产过程,利用PLC、SCADA、变频器在工控领域中的优点,设计了一种基于网络和PROFIBUS-DP、RS-485总线技术的电机群网络管控一体化的PLC-SCADA系统。借助网络和总线实现对电机群传动系统的管理和控制。通过在纺织印染机构多单元电机传动中的应用,实践证明该控制方案可靠、有效。