MHD simulation of high-current subsonic vacuum arc under different distributed axial magnetic fields

Based on two-temperature magnetic hydrodynamic (MHD) model, the influence of saddle-shaped distributed axial magnetic field (AMF, linearly increases along radial position) and bell-shaped distributed AMF (linearly decreases along radial position) on plasma loss and heat flux density to anode in subsonic high-current vacuum arc (HCVA) is simulated and analyzed. According to the simulation results, the saddle-shaped AMF can more effectively inhibit plasma loss from arc column than that of bell-shaped AMF. Comparisons between simulation results and experimental results further verify the correctness of model and simulation.     

理学SMX-10/11型X荧光光谱仪的改进

对理学SMX-10／ll型X荧光光谱仪真空系统、样品定位系统及热交换器冷却水循环路径等易发生故障部位进行改进，并在11型仪器上增加了S元素分析通道。生产应用表明，改进效果良好，简化了分析工艺。降低了分析成本，提高了仪器的稳定性。     

Bioeffects of Low Energy Ion-Beam Implantation and Vacuum Treatment on M1 Arabidopsis Thaliana

Vacuum treatment and ion-beam bombardment are two major processes in the low energy ion-beam implantation. To accurately study the contributions of these two major factors to the bioeffects separately, the M1 generation variation of Arabidopsis thaliana with ion-beam implantation and vacuum treatment were compared through a series of key plant development parameters including morphological observation, biochemical assay and RAPD （random amplified polymorphic DNA） analysis. The results showed that ion-beam implantation had obvious effect on almost all of these parameters, and the vacuum treatment had some impacts on several morphological parameters such as the bolting time and the length of the primary stem. Taking the results together, the indication is that vacuum treatment has some slight contributions to the bioeffects of ion-beam implantation while ion-beam bombardment itself is the major creator of the bioeffects.     

铸造Ti—0.2Pd合金SF—1000双级风机叶轮的研制

Ｔｉ－０．２Ｐｄ合金ＳＦ－１０００双级风机叶轮是大型盐酸再生设备的主要部件，采用整体铸造方法制造，无论在技术上还是经济上都是十分有利的。本文主要介绍采用加工石墨，铸铁组合型，真空电弧凝壳熔炼铸造工艺，成功地研制出整体铸造风机叶轮。     

Crossflow microfiltration of gum arabic solutions: Comparison of the classical system with the co-current permeate flow system

Gum arabic is a natural gum exuded mainly by the trees Acacia senegal , currently used in the food industries for its emulsifying, thickening and stabilizing properties. Its present processing includes various operations providing a quite turbid product. Crossflow microfiltration could be interesting for the clarification and the cold-pasteurization of the gum arabic solutions. Several experiments were therefore made with the crossflow microfiltration unit at ENSIA, using two different systems: the classical one (without permeate circulation), and the co-current permeate flow system (CCPF) allowing the exploration of the low transmembrane pressures range. With gum arabic solutions of 0.17g solids g⁻¹ solution and 70°C, the best results after 60 min of filtration (105.7 L h⁻¹ m⁻², 4.4% of solids retention and 83.4% of clarification) were obtained with the CCPF system at low transmembrane pressure and high crossflow velocity (0.3 bar and 7.5ms⁻¹).     

Air Filtration and Radon Decay Product Mitigation

Air cleaning as a means of mitigating the risks arising from exposure to indoor radon progeny has been evaluated in a single-family house in the north eastem US. using an automated, semi-continuous activity-weighted size distribution measurement system. The measurements included radon concentration, condensation nuclei count, and activity-weighted size distribution of radon decay products. Measurements were made in the house with and without an operating air filtration system and with various particle sources common to normal indoor activities operating. Aerosols were generated by running water in a shower, candle burning, cigarette smoking, vacuuming, opening doors, and cooking. Using a room model, the changes in attachment rates, average attachment diameters, and deposition rates of the unattached fraction with and without the air cleaning system were calculated. In the presence of active aerosol sources, the air filtration unit typically reduced the concentration of particles within the hour following the end of particle generation. After candle burning, cigarette smoking, and vacuuming in the bedroom, the reductions of PAEC by air filtration are about 60% with the air filtration system operating in the bedroom. During cooking in the kitchen, the reductions of PAEC in the bedroom with the air filtration system were about 40%. However, for all cases the dose reductions were smaller than the particle and PAEC reductions. For those particles that were generated within the bedroom, there was a 20% to 50% reduction in dose. In the case of cooking where the door was open and particles infiltrated from the rest of the house, the dose reduction was only 5% on average and appears to be insignificant. Thus, the dose reductions were h e r than the reductions in activity concentration, but there were no cases where the estimated dose actually increased.     

皮革真空鞣制新技术与设备的研究

本文对皮革在真空状态下鞣制进行了试验研究，使鞣制过程的物理—化学氛围得到改善，大大缩短了鞣制时间，废液排放量减少一半以上。     

能量"三环节"理论在原油蒸馏装置扩能改造中的应用

中国石化扬子石化股份有限公司炼油厂在第一套常减压蒸馏装置扩能改造中，使用了多项节能技术以实现能量的优化利用。本文以标定数据为基础，运用能量“三环节”理论对该装置的用能状况进行了计算和分析，从能量利用角度对装置的扩能改造效果进行了评价，并为装置的进一步优化能量利用提出了相应措施。     

湘潭新大粉末冶金设备制造有限公司的一体化真空烧结炉

简要介绍了湘潭新大粉末冶金设备制造有限公司研制的一体化真空烧结炉的炉子结构、脱蜡系统、工艺气体的引入系统、设备的控制系统以及炉子性能的鉴定结果。     

高压锅炉补给水系统管道的腐蚀

讨论了锅炉补给水管道的腐蚀情况 ,指出溶解氧和二氧化碳是产生腐蚀的主要原因 ,其腐蚀速率为0 .4 2mm/a。确保真空除气系统正常运行和二级除盐水箱的密封效果是控制腐蚀的主要手段。在此情况下 ,该管线尚可运行 7年