Energy Saving in Ultra High Vacuum Systems

In UHV, bakeout is employed to reach very low pressure. We have tested two bakeout systems: resistance and IR lamp heaters and we have realised that with IR Lamps we have energy and time saving.     

表面系统的表征

需要对表征工程表面的参数进行简化，使之合理化，近年来新提出的参数越来越多，而其必要性并未得以论证，本文建议表面的表征应与其功能相结合，并首次提出用以表征多表面系统的理论框架。     

油中水滴真空蒸发动态特性研究

为了获取油液真空蒸发脱水的动态特性,采用“假想薄膜理论”,考虑了Stefan流、水滴瞬态加热等因素,建立了油中水滴的蒸发过程的质量守恒、能量守恒方程以及水滴运动的耦合方程;分析了油液真空蒸发脱水这一复杂的耦合过程中油中水滴表面蒸发特性,水滴在油中的传质、传热效能及其影响因素;结果表明油液环境介质利于水滴与环境的传热,且真空压力对水滴蒸发的效能具有较大的影响,对深入研究真空滤油机的油水分离机理奠定前期基础.     

Deformations of Working Elements in Oil Free Scroll Vacuum Pumps

The mechanical and thermal causes of deformations of the orbiting and the fixed elements of oil free vacuum pumps are considered. Basic data for deformation calculation are geometric dimensions of the pump and dependence of working chamber volume on the orbiting scroll element rotation angle. Gas temperature and pressure values in each vacuum pump chamber are obtained with the help of a working process mathematical model. Deformation calculation is carried out by the finite element method realized in the software ANSYS. It is shown that deformations caused by pressure‐induced mechanical forces do not have considerable influence on the change of radial clearances between the scrolls. They may not be taken into account for pumping characteristics calculation. Thermal‐induced deformations are much greater, and the change of the clearances due to this cause may be 25 % and even larger.     

食品接触材料中橄榄油总迁移量的风险分析

抽取8种材质273批食品接触材料及制品,对其进行适宜性判定、水分敏感性确认以及橄榄油总迁移量测试,分析不同材质食品接触材料的检出风险。结果表明,在适宜性判定方面,PVC材质适宜性判定不通过率为100%;PE、PET、氯乙烯-偏氯乙烯共聚树脂和纸铝塑盖膜材质的适宜性判定全部通过;TPE、PP及金属涂层材质则由于添加剂的干扰出现适宜性判定部分不通过。在水分敏感性方面,PET和纸铝塑盖膜试样均为水分敏感性试样,需要进行水分含量调节的概率为100%;TPE材质因添加剂、暴露时间等因素不同,需要进行水分含量调节的概率为48%;其他几种材质不需要进行水分含量调节。在迁移试验检出方面,TPE、PP和纸铝塑盖膜材质的检出风险较高,分别为86%, 58%, 50%;PE、PET、金属涂层材质检出率为7%, 9%, 9%,有一定的检出率,但是总体迁移风险不高;氯乙烯-偏氯乙烯共聚树脂材质加校正因子后符合限量要求。在迁移试验前,应优先做适宜性判定、水分敏感性确认及调节,确保测试结果的准确性与有效性,为食品接触材料及制品的安全管理和质量控制提供数据支持。     

超高真空技术在表面处理系统中的应用

超高真空的获得与测量技术于1950年左右在加拿大和美国问世.今天,伴随着半导体设备、平板显示器、磁和光磁存储器设备等制造业的发展,每隔一个月就要求推出新型有效的生产体系.在这些表面设备的生产系统中,许多都要求局部超高真空或要求整个工艺处理过程置于超高真空环境中.设计一个优质、高效的超高真空系统及操作工艺是达到理想效果的关键.在这里,我们只有科学理解气体分子和特殊表面物化结构间的相互作用,才能很好地解决各种工程问题.具备了关于等离子体和超高真空室壁及内部装置的表面间的相互作用的经验,就可以很好的解决等离子体的控制问题.近年来,显示器件使用的某些有机材料的开发应用,给超高真空技术提出了新的挑战.消费产品的大批量生产推动和改进了高效超高真空系统的设计.     

超高真空陶瓷管内壁镀膜的方块电阻测量

使用一种新的感应线圈方法对超高真空陶瓷管内壁导电膜的方块电阻进行了测量,其优点在于不用直接接触膜层就能测量到管内深处不易放置探针的地方的方块电阻;可进行在线测量而不破坏管内真空.解决了应用中的难题,具有较高的实用价值.     

Interstitial Hardening of the Surface of Titanium Alloys by Vacuum Heat Treatment

We have determined the kinetic parameters of interaction of VT1-0, VT5, OT4-1, and VT16 alloys with a rarefied gaseous medium. We have established the interrelation between the parameters of chemical heat treatment (T, τ, and p, the interstitial hardening of surface layers of the metal, and its phase and structural state. The conditions of saturation (T, τ, and p) being equal, hardened layers differing in the microhardness and thickness of the layer H and l are formed on titanium alloys of different structural classes. Single-phase VT1-0 and VT5 α-titanium alloys as well as OT4-1 pseudo-α-alloy are the most sensitive to the conditions of gas saturation: the hardness and its gradient in the hardened layer grow significantly. As the β-phase content increases (VT16), changes in the parameters of chemical heat treatment affect less the hardness of the surface layer, but the depth of the hardened zone grows with temperature T and time τ. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 2, pp. 63–70, March–April, 2005.     

减二线馏分油中炼厂常用钢材的动态冲刷腐蚀行为

为了更好地解决炼厂在流动条件下减二线馏分油对管路的腐蚀问题,研究了流动条件下Q235碳钢和Cr5Mo合金钢的耐环烷酸和硫冲刷腐蚀性能,并与炼厂常用钢材渗铝碳钢和304不锈钢进行比较。结果表明:Cr5Mo钢的腐蚀速率明显小于Q235钢的,酸值越大两者的腐蚀差别越明显(酸值>5 mg KOH/g);随着酸值和硫含量的增大,Q235钢腐蚀速率有明显增大的趋势; Cr5Mo钢的腐蚀速率随着酸值的增大基本保持不变,甚至有一定的下降;相比于Q235(腐蚀速率6.3 mm/a)和Cr5Mo钢(腐蚀速率1.5 mm/a),渗铝碳钢和304不锈钢表现出优异的耐冲刷腐蚀性能,渗铝碳钢腐蚀速率为0.2 mm/a,而304不锈钢几乎没有失重。     

表面改性对含油纳米制冷剂中颗粒油相迁移特性的影响

普通含油纳米制冷剂在沸腾时颗粒容易在富油层中团聚,导致油相迁移率极低,无法保证纳米颗粒随制冷剂-油在制冷系统中稳定循环。表面改性可抑制颗粒团聚,故有望提高油相迁移率。本文采用吸光度法测量了不同改性纳米颗粒在含油制冷剂沸腾时的油相迁移率,并研究改性剂碳链长度、纳米颗粒与改性剂之间的嫁接方式对油相迁移特性的影响。实验所用含油纳米制冷剂为Ti O2/R141b/NM56,表面改性剂种类包括C1TMS、C3TMS、C8TMS、C16TMS和CTAB。结果表明:5种改性剂均可提高油相迁移率,C16TMS改性效果最好,其油相迁移率最高增加了131.2%;随着改性剂碳链长度从1增加到16,改性效果增加了5.48%~20.11%;共价键嫁接的方式比通过静电吸引的方式改性效果更好。     

罗茨油环机组在真空感应炉上的应用

真空感应炉真空机组中的前级泵，历来使用滑阀泵。但因原材料的灰份多，泵油很容易污染，致使泵卡死。在３０００磅真空感应炉上改用浙江真空设备集团有限公司生产的罗茨油环机组机替滑阀泵，取得了较好的效果。     

Thermal Migration of Melted Zones over the Silicon Surface under Thermal Shock

Technical Physics Letters - In this paper, we examine the issues of the formation and propagation of melted zones during electric explosion of thin aluminum films on the oxidized silicon surface. A...     

包装纸表面有机污染物向食品迁移性能分析

目的模拟苯酚(Phenol)、2,6-二异丙基萘(2,6-DIPNs)及邻苯二甲酸二丁酯(DBP)等3种有机污染物穿过纸张向所包装食品迁移的过程,同时测定以上3种有机污染物在纸张与空气之间的分配系数(Kp,a)。方法根据纸张具有孔隙结构的特点,引进线性阻滞系数(Rm)的概念对菲克第二定律(Fick′s law)进行修正,将修正后的迁移方程解与迁移实验结果进行对比,得到有机污染物在纸质包装材料中的扩散系数(Dp)值。结果在75℃与100℃的条件下,Dp值的数量级介于10-5~10-4之间,与已有的研究结果相符合。结论与Dp一样,Rm也是描述纸质包装材料中有机污染物迁移性能的重要参数之一。     

Systems Approach to the Metrological Estimation of Surface Quality

A new stage of scientific and technical progress has led to more complex surface geometries being used in advanced engineering.     

响应曲面法橄榄油微胶囊化工艺优化研究

目的通过响应曲面试验确定制备橄榄油微胶囊的最佳工艺。方法以大豆分离蛋白和黑木耳多糖为新型壁材,橄榄油为芯材,亚麻籽胶为乳化剂,采用乳液聚合-冷冻干燥法制备橄榄油微胶囊,其实验指标为包埋率,并利用透射电镜观察微胶囊的形态。结果在固形物质量分数为15.4%、壁芯材体积比为5︰1、乳化剂的质量分数为0.24%的条件下,包埋率可达到77.22%。通过透射电镜观察微胶囊形态可知,橄榄油微胶囊基本呈圆球形,分布均匀,包埋效果较好。结论响应曲面试验可以很好地对橄榄油微胶囊的制备工艺条件进行优化,制备的橄榄油微胶囊对橄榄油的抗氧化作用有着加强效果。     

The Use of a Floating Electromagnetic Level Gauge in Surface Oil Tanks

A level gauge for measuring the level of oil in vertical surface tanks, which is highly reliable and accurate and has a comparatively simple construction, is described. The construction of the electric circuit of the level gauge and data of an experimental structure and its accuracy characteristics are presented.__________Translated from Izmeritel’naya Tekhnika, No. 5, pp. 43–47, May, 2005.     

LC-DAD-FLD法测定金属包装彩印面3种光引发剂的迁移量

为了评估金属包装彩印面的光引发剂迁移风险,建立了一种基于液相色谱(LC-DAD-FLD)分析金属包装彩印面中BP、4-MBP和2-ITX 3种光引发剂迁移量的检测方法。并对DAD的检测波长、FLD检测的激发波长和发射波长等参数进行了优化,对食品模拟液和迁移条件进行了选择。实验结果表明,对液相色谱条件进行优化后,3种光引发剂BP、4-MBP和2-ITX的检出限分别为0.05,0.05,0.003 mg/L,加标回收率为90.88%~106.83%,精密度小于7.90%。可见,所提方法满足Eu PIA对于BP、4-MBP和2-ITX的特定迁移限量要求。     

Fermi Surface and Electronic Structure of Incommensurate Charge-Density Wave Systems

We study the single-particle spectra of a model that shows an incommensurate charge-density wave (CDW) instability arising from the competition between phase separation and long-range Coulomb interactions. Starting from an open Fermi surface, we find that the resulting CDW is oriented along the (1, 0) and (or) (0, 1) direction, which allows for a purely one-dimensional (1D) or a two-dimensional (2D) eggbox type charge modulation. In both cases, the van Hove singularities are substantially enhanced, and the spectral weight of Fermi surface states near the M points tends to be suppressed. Remarkably, a leading edge gap arises near these point, which, in the eggbox case, leaves finite arcs of the Fermi surface gapless.