真空烧结温度对多孔钛影响的研究

以碳酸氢铵做造孔剂,采用真空烧结法制备出生物多孔钛．研究了烧结温度对多孔钛显微形貌、显气孔率、抗压强度的影响．研究表明,提高烧结温度,有利于Ti晶体的发育,并提高制品抗压强度．     

基于VPN的株洲某污水泵站远程监控系统的设计与实现

为顺应系统远程监控的发展趋势,以株洲某污水泵站为背景工程,分析了该泵站和上位机的系统配置,并采用虚拟专用网(VPN)技术,把PLC工业控制和远程通讯结合起来,实现了该远程控制系统。同时介绍了VPN网络的定义及其技术特点,阐述了整个系统的结构及VPN网络在其中的关键作用。现场运行情况证明了该方案具有较强的可行性。     

Study on the characteristics of erbium-doped waveguide ring laser

A theoretical model of the erbium-doped waveguide ring laser is established according to the theory of erbium-doped waveguide amplifier and the transmission matrix of waveguide directional coupler. The influence of bend radius, coupling coefficient and doped erbium ion concentration on the characteristics of waveguide ring laser is investigated. It is shown that due to the co-action of waveguide bend loss and other relevant loss there is an optimal bend radius which can provide simultaneously low threshold pumping power and high laser light output power. As one part of the resonator’s loss, the laser light coupling coefficient of directional coupler has an impact on the laser property. The analysis indicates that the laser achieves the high output power when the coupling coefficient is about 0.2. The threshold pumping power is the minimum when the doped erbium ion concentration is 0.85×10²⁶ m⁻³. Increasing the concentration of doped erbium ions will enhance the output power of laser light as long as the concentration doesn’t introduce remarkable up-conversion effect. The results give a good theoretical basis for the design and fabrication of erbium-doped waveguide ring laser devices. Supported by the National Natural Science Foundation of China (Grant No. 60807015), the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 200801411037), the Young Teacher Cultivation Foundation of Dalian University of Technology (Grant No. 893210) and Doctor Start-up Foundation of Dalian University of Technology (Grant No. 893322)     

CO2 gasification of wood charcoals derived from vacuum and atmospheric pyrolysis

The gasification of biomass derived char obtained via vacuum and atmospheric pyrolysis of Populus tremuloides has been studied in the ranges of 725–960°C and 0.1 to 6 MPa. CO₂ was used as the oxidizing gas. The results show that char reactivity is influenced by the preheating rates and that pressure effects are significant between 850°C and 950°C. A correlation based on the expression: df/dt = k₀{exp(-E/RT)}(1 - f)^af^βP^yCO₂ was used to fit the experimental data. In general, vacuum pyrolysis derived char showed a higher reactivity than atmospheric pyrolysis chars. An explanation based on a higher oxygen content of the vacuum pyrolysis char is suggested.     

蒸汽喷射真空泵的影响因素及测试罩的应用

实际生产中的影响因素很多 ,诸如蒸汽压力、蒸汽干燥度、冷却水量、冷却水温、冷却水喷嘴堵塞、真空泵泄漏、拉瓦尔蒸汽喷嘴堵塞、泵前工艺设备冷却效果不好等等。但主要的是冷却量、拉瓦尔蒸汽喷嘴和泵前工艺设备的冷却。测试罩安装在真空泵的吸入真空管道上 ,在测试罩上选择不同直径的空气流量喷嘴 ,可以测得真空泵的空气流量喷嘴、抽气量、真空度之间的关系 ,从而可指导正确操作。     

塔架式抽油机的远程控制系统

针对传统的抽油机远程控制系统存在的弊端,提出了新型的控制层结构,设计了三层架构的远程控制系统;设计即时通信系统应用于远程控制系统中,详细地分析其服务器、电脑客户端和移动客户端的构架,实现管理层和控制层之间的信息交互;设计了基于WiFi的网络通信模块与上位机进行通信,介绍远程控制终端的核心控制模块,实现对电机的控制。经过测试,系统具有即时性、高可靠性以及快速性,确保对抽油机的有效控制,具有一定的工业价值和推广价值。     

支持向量机的无杆抽油机示功图自动识别技术

针对抽油机示功图人工目测误差大、效率低的现状,研究了基于支持向量机理论的示功图自动识别技术。提出了基于支持向量机理论对示功图进行自动识别的可能性,提供了基于支持向量机理论的示功图自动识别步骤,并对无杆抽油机正常、供液不足、游动凡尔泄漏以及油管漏失4种工况下的示功图进行了自动识别研究。识别结果表明:基于支持向量机理论的示功图自动识别方法能对以上4种工况的示功图进行准确有效的识别。     

一种高效节能真空电熨斗的研究

为了提高电熨斗的安全性,同时降低其能耗,设计了一种高效节能的真空电熨斗,该电熨斗通过保温装置及真空导热装置,可以实现快速导热及长时间非通电状态下工作,具有安全可靠,高效节能,使用方便,成本低廉的特点,具有良好的市场推广前景。     

Intensification of low-grade methane enrichment in nitrogen mixture by CH4/CO2 displacement

To solve the problem of CO₂ uncompleted desorption in the process of CO₂ displacement enhancing the adsorption separation of CH₄/N₂, a small amount of product gas CH₄ was used as purge gas to improve the CO₂ desorption. CH₄/CO₂ mixture gas obtained from desorption step was recycled as the displacement gas to enhance the enrichment of low-grade methane in nitrogen mixture. In this work, the research conducted the experiments for CH₄/N₂ separation using CH₄/CO₂ displacement intensification adsorption and the laboratory-made coconut shell activated carbon as sorbent. The mathematical models were built in gPROMS and the accuracy of models was verified by comparison of simulations and CH₄/N₂/CO₂ breakthrough experiments. The performance of enrichment of low-grade methane with displacement intensification using different displacer was compared. The result showed that the process with CH₄/CO₂ displacement had higher purity product than CO₂ displacement. The CH₄/ CO₂ mixed gas replacement enhanced vacuum pressure swing adsorption cycle experiment was carried out, which can jointly enrich 14% CH₄/ N₂ and 53% CH₄/CO₂ to 98.8%, and at the same time obtain a recovery rate of 77.8%.     

Optimization of spraying process and laser treatment of CoNiCrAlY

This article describes the investigation of a new generation of vacuum plasma sprayed CoNiCrAlY coatings on NiCr20Ti in the sprayed as well as the laser-treated condition. The aim of the study was the improvement of MCrAlY coating properties by modifying the microstructure through laser remelting with 5-kW Co₂: lasers. Parameter analysis and optimization was carried out for the vacuum plasma spraying process, as well as for the laser remelting technique. The effect of the laser treatment on microstructure, quality of the coatings, and oxidation as well as hot gas corrosion behavior are reported.