白光反射谱测薄膜厚度实验

本实验利用白光的反射谱采测薄膜的厚度,利用单色仪测量不同波长光的干涉光强度,把对条纹的测量转变为对不同波长干涉光强度的测量,既可以手动也可以利用数据采集系统自动采集和处理数据,使操作和测量更加简洁方便.     

用面阵CCD测量不规则平面物体的面积

文中介绍了利用面阵CCD测量不规则平面物体面积的原理和方法。对影响测量精度的各种因素进行了分析,比较了利用面阵CCD进行测量和利用线阵CCD进行测量的不同。通过实际测量,证明本方法具有测量速度快,测量精度高,适应性强等特点,具有广泛的应用前景。     

Minitab在C开关组件操作力矩测量系统分析与改进中的应用

该文旨在利用Minitab软件进行测量系统分析和改进。通过K公司C开关操作力矩超差,初步分析锁定测量系统为改进对象后,利用Minitab进行测量系统分析,发现问题,并改进测量系统,最终又通过Minitab软件进行测量系统的改进效果确认。     

基于光电编码器的转速测量系统设计与仿真

文章首先介绍了利用光电传感器进行转速测量的基本原理,在此基础上介绍利用光电编码器进行转速测量的信号特征和处理电路,并设计以AT89S51单片机为控制中心的编码器转速测量电路;详细分析软件实现的方法,并给出设计的汇编语言程序,利用Proteus软件进行仿真得到预期的测量结果。     

基于加工中心的在机测量系统

开发了利用加工中心和自行开发的测量软件实现的坐标测量系统。在加工中心主轴上安装触发式测头,利用加工中心的高精度行走机构,运行在机测量软件生成的测量主程序和典型几何特征的测量宏程序,对在机加工的工件进行坐标测量;测头接触工件时产生触发电信号,数控系统记录此时的机床三个坐标值作为测点数据,测量完成后将所有的测点数据传送回测量软件;利用编制好的算法对工件实现尺寸、形状和位置误差的计算与评价,使加工中心实现坐标测量机的功能。     

振弦式转矩、转速、功率测量装置

本装置利用振弦技术测量转矩,利用光电技术测量转速及利用微机技术进行信号处理和运算,使装置具有测量范围宽、抗干扰能力强、测量精度高、安装使用方便等优点,满足船舶、机车等动力主轴的转矩、转速、功率测量的要     

单目视觉位姿测量的线性求解

利用定位特征点在图像中的坐标求解空间位姿算法是单目视觉位姿测量技术中的关键.针对这个问题,在距离因子的基础上建立了非线性的位姿测量模型.利用代数变换方法将非线性测量模型转化成线性非齐次方程组.根据代数变换过程中变量之间的相互关系,建立方程组通解之间的乘积关系方程组.再次利用代数变换对乘积关系进行线性变换,并利用P4P问题中共面特征点姿态测量唯一解的特性,实现位姿测量的线性求解.通过数值仿真和实际测量两个试验对该位姿测量算法进行了精度验证,试验数据表明该方法可以有效抑制图像噪声干扰,提高位姿测量的精度.     

大型轴承径向游隙测量方法

根据径向游隙的测量原理,利用已有条件设计了一种利用轴承自重测量轴承径向游隙的简易方法。该方法可在保证测量载荷的情况下准确测量轴承径向游隙,结构简单、使用方便、测试效率及准确性较高,而且成本较低。     

校准件在检验夹具设计中的应用

通过具体实例，论述了校准件在检验夹具设计中的作用，总结了校准件应用于相对测量的主要优点：利用校准件能使难以测量的尺寸便于测量；利用校准件可使复杂的测量简化，提高检验效率；利用适当形式的校准件可简化检具精度要求的复杂性。同时还指出了校准件设计的注意事项。     

基于遗传算法的机器人最优测量构型研究

研究了机器人标定中最优测量构型的选择，采用奇异值分解方法获得了机器人位姿测量构型的观测指标。以该指标为优化的目标函数，利用遗传算法来选择机器人的一系列最优测量构型，以最小化参数估计中测量和建模误差的影响。实验结果表明，利用该方法获得的最优测量构型的标定结果优于随机选择的测量构型的标定结果。     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.     

COMPUTER SIMULATION OF CONTINUOUS ELECTROMAGNETIC STIRRING FOR MAKING RHEOLOGIC SEMI-SOLID SLURRY OF ZL112Y ALUMINUM ALLOY

To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and fluid velocity field in the alloy melt in a crucible tube in three coils. In the first section of the paper, eletromagnetic force field and fluid velocity field caused by single coil were simulated. The result of this simulation gives an average velocity of 3.2 cm/s and it is called critical velocity because a fluid velocity over it will cause a fine and spherical structure of solid primary a in a semi-solid melt. And, from this result, a reasonable temperature of semi-solid of the alloy and an electrical current intensity were established. The electrical current intensity of the result of this simulation corresponded to the current intensity used in a practice experiment, in which the primary α was obviously refined and sphericized. Based on this simulation of single coil electromagnetic stirring, in the second section of the paper, eletromagnetic force field and fluid velocity field caused by three coils were simulated. The result of the simulation shows that, 1） there is a semi-solid zone of 32 mm from bottom of the crucible tube to the upper; 2） the electrical current intensities of three coils of 400 A, 600 A, and 400 A, which were set to top range, middle range and bottom range of the tube, respectively, were the optimum parameters of electromagnetic current intensity under the condition of this investigation; and 3） under effect of these electromagnetic current intensity, the fluid velocities of the melt in the tube were 6.3 cm/s in top range, 3.75 cm/s in middle range, and 3.9 cm/s in bottom range of it, respectively.     

Imaging applications of synchrotron X-ray phase-contrast microtomography in biological morphology and biomaterials science. I. General aspects of the technique and its advantages in the analysis of millimetre-sized arthropod structure

Synchrotron‐generated X‐rays provide scientists with a multitude of investigative techniques well suited for the analysis of the composition and structure of all types of materials and specimens. Here, we describe the properties of synchrotron‐generated X‐rays and the advantages that they provide for qualitative morphological research of millimetre‐sized biological organisms and biomaterials. Case studies of the anatomy of insect heads, of whole microarthropods and of the three‐dimensional reconstruction of the cuticular tendons of jumping beetles, all performed at the beamline ID19 of the European Synchrotron Radiation Facility (ESRF), are presented to illustrate the techniques of phase‐contrast tomography available for anatomical and structural investigations. Various sample preparation techniques are described and compared and experimental settings that we have found to be particularly successful are given. On comparing the strengths and weaknesses of the technique with traditional histological thin sectioning, we conclude that synchrotron radiation microtomography has a great potential in biological microanatomy.     

ESTIMATION OF THE NUMBER OF CORRELATED SOURCES WITH COMMON FREQUENCIES BASED ON POWER SPECTRAL DENSITY

Blind source separation and estimation of the number of sources usually demand that the number of sensors should be greater than or equal to that of the sources,which,however,is very difficult to satisfy for the complex systems.A new estimating method based on power spectral density (PSD)is presented.When the relation between the number of sensors and that of sources is unknown, the PSD matrix is first obtained by the ratio of PSD of the observation signals,and then the bound of the number of correlated sources with common frequencies can be estimated by comparing every column vector of PSD matrix.The effectiveness of the proposed method is verified by theoretical analysis and experiments,and the influence of noise on the estimation of number of source is simu- lated.     

INFLUENCE OF ROLL DIAMETERS ON DEFORMATION BEHAVIOUR OF HIGH TEMPERATURE SUPERCONDUCTING TAPE

During plastic process,the material flow is strongly influenced by the contact area between deformed workpiece and die.In rolling process,difference of roll diameter makes the contact area between roll and deformed tape different,which leads to different material flow and the distribution of powder density.A numerical modelling of the first rolling process for 61-filament high temperature superconducting tape is constructed and the influences of roll diameters on deformation behavior of the tape are discussed.It can be found that the BiSrCaCuO(BSCCO)powder in the center of the tape has higher relative density than those in the periphery of the tape during rolling process.With the increase of roll diameter,the length of the contact arc in the roll gap expands which lead to the in- creasing of transversal strain and the decreasing of the related longitudinal strain.It makes the value of longitudinal strain ratio decrease gradually,which decreases the possibility of occurrence of the transversal shear band,simultaneously it increases the risk of occurrence of longitudinal crack.     

DETECTION METHOD OF SPOT WELDING BASED ON MULTI-INFORMATION FUSION AND FRACTAL

A novel detection method of support vector machine （SVM） based on fractal dimension of signals is presented. And models of SVM are made based on nugget size defects of spot welding. Classification using these trained SVM models is done to signals of spot welding. It is shown from effect of different SVM models that these models with different inputs. In detection of defects, these models with inputs including sound signal have a high percentage of accuracy, the detection accuracy of these models with inputs including voltage signal will reduce. So the SVM models based on fractal dimensions of sound are some optimal nondestructive detection ones. At last a comparison between SVM detection model and ANNS detection model is researched which indicates that SVM is a more effective measure than Artificial neural networks in detection of nugget size defects during spot welding.     

利用裂解气相色谱-质谱联用技术分析纸浆漂白过程中木素结构的变化

利用裂解气相色谱-质谱联用（PyGC-MS）技术分析竹子硫酸盐浆原浆，氧脱木素后纸浆，二氧化氯漂白后纸浆中残余木素。实验结果表明，二氧化氯漂白浆残余木素的热稳定性高于未漂浆和氧脱木素浆残余木素，未漂浆和氧脱木素浆残余木素的热稳定性十分接近，不同温度点的热失重相差甚微。经过氧脱木素和二氧化氯漂白后，木素结构均受到一定程度破坏，其中氧脱木素由于处理条件剧烈，导致木素结构稳定性最差，因此氧脱木素浆残余木素的低沸点裂解碎片的含量最高。     

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.     

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post‐translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post‐translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ～1 ng/mL. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:685–732, 2011