A photoreactor on the basis of a Xe2 excilamp

A photoreactor developed on the basis of a Xe₂ excilamp with a power of ～10 W (with a power density of 15 mW/cm² emitted from a surface of ～700 cm²), which can operate in liquids and gases at a pressure of up to 40 atm, and a multifunctional cell with an active volume of ～760 cm³ is described. Data on water photolysis in a natural gas exposed to VUV radiation with λ=172 nm are presented.     

An instrument for measuring the intensity and dose of cancerigenic ultraviolet radiation

An instrument for measuring the intensity and dose of cancerigenic radiation from the Sun and artificial sources has been developed. A 4H-SiC Schottky barrier photodetector is used as the sensor. The sensitivity spectrum of the photoelectric transducer lies in the region 240–300 nm and has a maximum at 260 nm. The quantum efficiency is ≈0.3 electrons/photon (at λ = 254 nm), and its temperature coefficient at T = 250–310 K is < 0.1%/°C. The dimensions of the device are 3 × 6 × 11 cm.     

Development of a holographic particle diagnostic system and its application to measurements of spray characteristics

Particle diagnostics involving three dimensional distributions are important topics in many engineering fields. The holographic system is a promising optical tool for measuring three dimensional features of particles. In this study, we developed a holographic particle diagnostic system with diffused illumination to measure the sizes and 3-D velocities of moving particles using automatic image processing. First, basic optical systems for pulse laser recording, continuous laser reconstruction, and image acquisition were constructed. One of inherent limitations of particle holography is its long depth of focus in particle images, which causes considerable difficulty in determination of particle positions in the optical axis. To solve this problem, three new auto-focusing parameters (AFPs) corresponding to particle sizes were introduced. The developed system was applied to spray droplets to validate its capabilities. Three dimensional positions of particles viewed from two sides were decided using AFPs and then three dimensional particle velocities were extracted using a particle tracking algorithm. Comparison of measured sizes and three dimensional velocities of particles with those obtained using a laser instrument, PDPA (Phase Doppler Particle Analyzer), showed that the developed holographic system produced consistent results.     

Laser-heated emission of electrons from a carbon-coated metal surface and its application to the emissive probe measurements

An electron source utilizing the CO(2) laser-heated electron emission from a carbon-coated metal surface has been experimentally studied. This type of emission may have the advantage that no potential gradient exists in the vicinity of the metal surface and emission from a surface of very small dimension and of arbitrary shape can be easily obtained. Experimental emission current characteristics for various target temperatures were given and discussed. An application to the emissive probe for measuring the plasma space potential is shown. The results obtained by the emissive probe are also checked independently by using the rf probe method.     

高压气淬真空炉控制系统的改造与应用

对HVQ系列热处理真空炉的控制系统进行局部硬件改造,分析并提出从PLC控制向计算机控制转化的硬件改造思路和软件设计过程,成功地实现了真空炉的计算机监测与控制。     

500fs紫外激光系统及其在闪烁体荧光特性测试中的应用

介绍了用于高速时间记录设备以及多种闪烁体材料时间响应特性测试的500 fs,248 nm超短脉冲紫外激光系统的构成及其主要技术参数.系统的核心部分是一个分布反馈染料激光器,即一个稀疏刻线光栅的动态像.像的长度和染料溶液的折射率决定了脉冲的最短宽度,并且通过改变动态光栅的间距就可以改变输出光谱.在实验条件下,分布反馈染料...     

可编程序控制器可靠运行分析及应用

在自动控制系统的应用中,可编程序控制器占据着举足轻重的地位.由于现场条件的限制(例如老设备的改造),有时上百米长的强电电缆和PLC的信号电缆不能有效的分隔开,甚至只能敷设在同一电缆沟或桥架槽内.高电压、大电流接通和断开时产生的强电干扰可能会在PLC输入线上产生很强的感应电压和感应电流,足以致PLC产生误动作.另外,干扰信号也可能经PLC的电源侵入PLC,造成PLC损坏,给安全生产构成了极大的威胁.为了很好的加强可编程序控制设备在生产运行中的可靠性能,在使用过程中需要对其采取必要的防范措施.     

8031单片机在工业硅酸根浓度测量仪表中的应用

本文对由８０３１单片机,模数转换芯片,时钟芯片,串行通讯芯片,并通过扩展接口芯片外接液晶显示器,触摸键盘以及微型打印机构成一个多功能的单片机应用系统,并将其如何应用在工业硅奶浓度测量仪表中等情况进行介绍。     

An electric-discharge excimer radiation source on a set of Cl 2 * (258 nm) and ArCl (175 nm) bands

An excimer radiation source with transverse volume discharge pumping that operates simultaneously on a set of bands of 258 nm (Cl ₂ ^* ) and 175 nm (ArCl) is described. A spark UV preionization was used for the perionization of a discharge volume of 18×2.2.×1.0 cm³. The discharge was initiated in the mixtures Ar/Cl₂=(5–30)/(0.1–0.8) kPa. The source was optimized over the composition and pressure of the Ar/Cl₂ mixture. The service life of the excimer source on the electron-vibrational transitions Cl ₂ ^* and ArCl in the gas-static regime with a passive volume of 101 was of the order of 10⁴ pulses.     

转轴强度计算的相对当量弯矩法及其应用

对现有转轴强度计算的几种主要方法作了简评,为弥补这些方法的不足,提出了相对当量弯矩法.即转轴大多为阶梯轴,每一轴段的相对当量弯矩Mv定义为该轴段的最大当量弯矩Mcamax与该轴段直径d或平均直径d之比.在阶梯形转轴上,其最大相对当量弯矩Mvmax与最小相对当量弯矩Mvmin之比应不大于2.0.如果不满足,则应修改结构设计,其主要途径是重新设计轴上传动件的受力方向以改善当量弯矩在轴上的分布或适当改变轴径等.按该方法设计的转轴,各部位材料能充分发挥潜力,避免材料浪费.该珐能简捷地判断转轴结构设计的合理性,从而提高转轴的设计质量.转轴的强度计算宜以弯扭合成应力法和疲劳强度计算法为主导方法.但是为防止非危险截面尺寸过大而造成材料浪费,在轴的结构设计之后,按相对当量弯矩法对转轴进行校核计算,以判断结构设计的合理性.     

自适应的模糊增强算法及其在工程扫描图中的应用

由于噪声等原因,工程图在输入计算机时会使图象质量下降,造成图象中诸如细线、角点等重要的细节信息丢失和破坏。采用模糊理论,可以处理模糊信息的模糊增强算法能够有效地消除噪声和保护细节特征,使图象质量得到改善。但是图象转折点xc的合理选择是保证模糊增强效果的关键。因此,提出一种自适应模糊增强算法能够根据不同的图象自动选择最佳的转折点。实验证明,本算法具有较好的增强效果。     

An improved thermal reynolds equation and its application to the analysis of an elastohydrodynamic inlet zone

A thermal Reynolds equation with an exponential viscosity temperature variation is developed for contacts between surfaces with different velocities. The temperatures of the surfaces are equal. The equation is used to calculate the lubricant film in the inlet zone of elastohydrodynamically lubricated rolling contacts in the presence of slip.     

DKJ电动执行器在套筒窑的应用及维护

阐述了DKJ电动执行器的工作原理,介绍DKJ执行器组成的控制系统在梅山套筒窑的应用情况,总结DKJ电动执行器的故障诊断及维护方法。     

Development of a contact-type probe for measurements of ultra-fine-pitch gears and application to pseudo roughness evaluation

Gears used in actuators for robot articulations are showing a trend toward having smaller modules. Thus, profile measurements of small module gears are strongly desired. Our aim was to develop a probe artifact that enables ultra-fine-pitch cylindrical gears to be measured, by minimizing the size of the probe head. The configurations of the contact-type probe and holder were designed under consideration of interference with an adjacent tooth during profile measurements of an objective tooth. After manufacturing the artifact, a 0.1-module spur gear was measured as a trial, and reasonable results were obtained. In addition, a calibration plate for roughness was measured using the developed probe artifact. The evaluated roughness showed a strong correlation with the “true roughness”. Therefore, the developed probe can be expected to enable “pseudo” roughness to be evaluated.     

An anisotropic damage-based plastic yield criterion and its application to analysis of metal forming process

Based on the continuum damage mechanics (CDM), both the total damage growth force and the damage equivalent stress has been firstly derived. Material and damage are considered to be anisotropic in this theoretical model. A new damage-based plastic yield criterion, where the damage equivalent stress is taken as the yield function, and the corresponding damage evolution equation has been established. A relation between the damage variable and the plastic deformation has been proposed. This relation can be applied to obtain the damage history in terms of Moiré photo-mechanics technology in this work. In addition, from the anisotropic damage-based plastic yield criterion presented, the large-scale finite element codes ABAQUS/Explicit in conjunction with the damage experimental results has been then used to calculate some mechanical variable fields in metal forming process. It has finally been verified that the position corresponding to the maximum value in damage equivalent stress field accurately coincides with the initial place of macro-crack given by Erichsen cupping tests carried out by authors.     

Experimental investigation of a cavitating Venturi and its application to flow metering

An experimental investigation has been carried out to evaluate the performance of a cavitating Venturi flow. For that purpose, a closed loop circuit with a centrifugal pump and a transparent asymmetric converging-diverging test section has been built which allows to set the pressure level and the flow rate. The system is instrumented with several pressure sensors and temperature probes that are continuously monitored during the tests. The experiments have consisted in generating non-cavitating and cavitating flows inside the Venturi under controlled conditions. The obtained results, which have been characterized as a function of the Venturi's discharge coefficient, pressure ratio and pressure loss coefficient, are in good agreement with previous studies carried out with standard Venturi geometries, specially under non-cavitating flows. The Venturi's performance under cavitation flows has been found to be dependent on the Venturi's inlet pressure and similar to a chocked flow condition with constant volumetric flow rate. On the basis of these observations and the analogous behaviour with compressible gas nozzles, a new flow coefficient has been derived which remains constant at any cavitating regime. Thus, this coefficient permits to use a Venturi as a flow meter on cavitation conditions.     

An elastic-plastic constitutive equation for transversely isotropic materials and its application to the bending of perforated circular plates

Extending Hencky's interpretation for Mises' yield condition to anisotropic materials, it is first assumed that the plastic deformation occurs when the elastic distortion energy attains to a certain constant value. Then, the shearing stress and the shearing strain intensities are defined in terms of the elastic and the plastic distortion energy. By assuming the deformation theory of plasticity along with the hydrostatic pressure insensitivity of material response, trigonometric representations of stress and strain are derived in order to formulate an elastic-plastic constitutive equation for transversely isotropic materials. Yield conditions and the corresponding yield loci for the relevant materials are also discussed. As an application of the resulting constitutive equation, elastic-plastic bending of perforated circular plates is analysed by modelling them by equivalent homogeneous transversely isotropic plates.     

An ensemble local means decomposition method and its application to local rub-impact fault diagnosis of the rotor systems

Targeting the shock characteristics of the vibration signal of a rotor system with local rub-impact fault, a local rub-impact fault diagnosis method of rotor system based on ELMD (ensemble local means decomposition) is proposed in this paper. The local mean decomposition (LMD) is a newly self-adaptive time-frequency analysis method, by which any complicated multi-component signal could be decomposed into a set of product functions (PFs) whose instantaneous frequencies in theory have physical significance. Unfortunately, mode mixing phenomenon which makes the decomposition results devoid of physical meaning is common when LMD is performed in practice. Targeting this shortcoming, the filter bank structure of white noise by LMD is obtained by numerical experiments, and then an improved method based upon noise-assisted analysis, ensemble local mean decomposition, is put forward. In ELMD, firstly, different white noise is added to the targeted signal; secondly, LMD is used to decompose the noise-added signal into product functions (PFs); finally, the ensemble means of corresponding PF components derived from LMD is regarded as the final decomposition result. The analytical results from simulation signal and experimental rotor local rub-impact signal demonstrate that the ELMD approach can be used to overcome the mode mixing of the original LMD method effectively.     

An application of screw theory to the kinematic analysis of a Delta-type robot

This paper reports on the kinematics of a translational parallel manipulator whose topology is close to the architecture of the famous Delta robot. The displacement analysis is presented in closed-form solution by applying a new strategy based on the unknown coordinates of a point embedded to the moving platform. The input-output equations of velocity and acceleration of the robot are systematically obtained by resorting to reciprocal-screw theory. The singularities of the mechanism are explained through the input-output equation of velocity. Finally, a numerical example is provided to show the application of the method.