电源对介质阻挡放电（DBD）激发准分子（XeCl）辐射的影响

本文对电源参数如电压幅值，频率及正负电压对介质阻挡放电激发准分子XeCl紫外（308nm)辐射的影响进行实验研究，结果表明，UV辐射随电压幅度的增加而增加，但效率下降，提高频率，增加了放电次数，导致UV辐射的增强；此外，在较高的频率下，电压上升沿变陡，使得电子获得的能量主要用于原子的激发和电离，正、负电压放电的不对称源于电极结构的不对称而引起的放电过程的差异，负电压内电极可向放电管中馈入更多的能量；比较发光光谱可判断生成准分子的等离子体化学过程中没有明显的差别。     

梳状电极结构对大气压表面放电的影响

研究了梳状电极结构对大气压表面放电的影响,发现频率固定时放电电流随着外加电压的增加而增加,而电压固定时在某个频率范围内放电电流有最大值;在相同的电压和频率下较宽的电极条宽可以产生较大的放电电流,而电极条间距对放电电流几乎没有影响;用整块金属板做接地电极相比于梳状接地电极可以产生较大的放电电流;另外,较厚的高压电极可以在介质板表面产生更明亮、厚度更大的放电等离子体.     

一种新型的紫外光源--准分子紫外灯

非相干性紫外或真空紫外光源的应用已成为众多工业部门中一项基础性和关键性的技术.本文着重介绍一种使用介质阻挡放电激发紫外或真空紫外辐射的新型光源--准分子紫外灯,包括准分子的形成以及光源的紫外辐射效率.最后,对影响准分子辐射的因素如气压、气体组成、温度及电源频率和电压进行了初步的分析.     

基于放大单元实验的新型荫罩式PDP放电特性研究

设计制作了封闭的新型荫罩式等离子显示屏（SM-PDP）放大单元实验屏，对SM—PDP放电特性进行了研究。设计了相应的驱动电路，且驱动波形频率、占空比等参数可调。建立了放大单元的光辐射特性测试系统，研究了SM—PDP维持期的放电过程，扫描电极宽度对维持电压、红外辐射和放电效率的影响。结果表明，SM—PDP的放电过程为非均匀场中的对向放电过程，扫描电极变宽，维持电压降低，红外辐射沿电极扩展，但是放电效率降低。     

阻抗匹配对大气压氮气介质阻挡放电的影响

在介质阻挡放电装置中,使用阻抗匹配网络后,当气体间隙为3mm时,在大气压氮气中获得了均匀介质阻挡放电等离子体,放电模式为汤森放电.在其他放电参数不变的情况下,放电电流和放电功率随着外加电压峰峰值的增大先非常缓慢增加,然后当放电面积铺满整个电极后呈线性增加.而放电电流和放电功率随驱动频率的增加呈现出非常明显的谐振现象,实验所得到的最佳匹配频率和Chen给出的理论计算结果存在差异.     

大气压双频容性耦合Ar/O_(2)等离子体特性研究北大核心CSCD

文章利用二维流体模型对双频调制大气压Ar/O_(2)放电特性进行了研究,着重讨论高低频电压、低频频率等不同匹配方式对等离子体参数的影响,并且通过对电子加热模式、电子密度、中性粒子密度、正离子能量以及正离子总通量等分析了大气压Ar/O_(2)放电双频调控机制。结果表明,低频源电压的改变使得电子加热模式由α模式转变为DA/α混合模式,且等离子体密度、正离子总通量及离子能量均随着低频电压的升高而增大,发生了解耦现象。与低频源电压不同,高频源电压和低频源频率对电子加热模式不产生影响。此外,高频源电压对等离子体密度及正离子总通量影响较大,对刻蚀工业中易对材料造成损伤的离子能量影响很小;而低频源频率对工业中影响影响较大的离子能量和离子总通量影响较大,对等离子体密度影响较小,实现了等离子体密度和离子能量的独立控制。     

大气压双频Ar/O_(2)放电等离子体特性的数值模拟北大核心CSCD

文章采用等离子体流体理论模型,研究了双频容性耦合放电中高频源频率对大气压氩气与氧气混合气体放电等离子体的各类粒子密度与各项等离子体参数的影响。通过模拟不同高频源频率的放电,得到了放电空间中各类粒子的密度、电子温度、电场等参数的一维时空分布,进一步了解了双频放电中高频源频率对等离子体特性的影响作用。研究结果表明:当放电电压固定时,随高频源频率的升高,电子密度逐渐增大;电子温度、电场与电势有下降的趋势;各类氩离子密度与氩原子的亚稳态密度随高频源频率的升高而增大;随高频源频率的升高,各类氧离子密度增大,氧原子密度先减小后增大,氧分子的亚稳态密度先增大后减小。电子压力加热、电子欧姆加热、电子加热和能量损失受高频源频率的影响均逐步升高。此外,有效电流密度与有效功率密度随高频源频率的升高大体增加。     

容性耦合等离子体腔室放电特性仿真研究

容性耦合等离子体射频放电广泛应用于IC制造中的薄膜沉积、刻蚀工艺中,等离子体中的电子密度和平均电子温度直接影响离化及激发反应速率,其在放电腔室中径向分布的均匀性严重影响刻蚀和薄膜沉积的均匀性。以某12寸腔体为研究对象,采用Comsol软件仿真研究了功率电极电压、腔室气压和极板间距对等离子体的电子密度和平均电子温度的影响规律。仿真研究发现:在研究的气压、电压、极板间距范围内,电子密度和平均电子温度随电压的增加而增加,其均匀性随电压的增加而变差;电子密度随气压的增加而增加,平均电子温度随气压的增加而降低,电子密度的均匀性随气压的增加而改善,电子温度的均匀性随气压的增加先变差再变好;电子密度随极板间距的增加而增加,平均电子温度随极板的增加而降低,电子密度和平均电子温度的均匀性随极板间距的增加而变好。研究结果对指导等离子体参与的IC工艺腔室结构设计及工艺控制具有重要意义。     

荫罩式等离子体显示板条纹分布变化的研究

采用基于粒子-蒙特卡罗模型的OOPIC-PRO软件对荫罩式等离子体显示板(PDP)的放电进行模拟,研究扫描电极宽度、氖氙混合气体比例、气压等参数变化对主放电区域及条纹分布的影响,并与高速ICCD相机拍摄的条纹分布进行比较分析。模拟和实验结果表明:随着电极宽度增加,主放电区域增大,条纹区域减小,放电效率降低;随着氙比例和气压的升高,主放电区域减小,条纹区域增大,放电效率提高。研究结果揭示了PDP放电单元中条纹区域的粒子能量适宜激发产生辐射紫外光子的氙谐振态和激发态粒子,这对提高PDP的放电效率乃至发光效率尤为关键。     

一种新型的紫外光源—准分子紫外灯

非相干性紫外或真空紫外光源的应用已成为众多工业部门中一项基础性和关键性的技术,本着重介绍一种使用介质阻挡放民激发紫外或真空紫外辐射的新型光源－－准分子此外灯,包括准分子的形成以及光源的紫外辐射效率,最后,对影响准分子辐射的因素如气压,气体组成,温度及电源频率和电压进行了初步的分析。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.