LF精炼过程中吹氩畅通的技术措施

对ＬＦ精炼过程中如何保证吹氩畅通的实用技术措施进行了分析和总结，提出了进一步改进的措施。     

Potential of VHF-plasmas for low-cost production of a-Si: H solar cells

Compared to the use of the standard glow discharge technique the production of amorphous silicon solar cells by the very high frequency glow discharge (VHF-GD) bears yet additional cost reduction potentials:Using VHF-GD at excitation frequencies higher than 13.56 MHz, a more efficient dissociation of silane gas is obtained; thus, higher deposition rates are achieved; this reduces considerably the deposition time for intrinsic amorphous and microcrystalline silicon layers.Furthermore, by itself and even more so, in combination with argon dilution, VHF-GD technique improves silane utilisation and leads, thus, to further cost reduction.Finally, by combining the VHF-GD technique and the “micromorph” concept “real” tandem cells (i.e. a superposition of two cells with distinctly different band gaps) can be deposited at low temperatures without the use of expensive germane gas.     

Ar~ 激光诱导微血栓形成及阿司匹林作用的研究

应用氩离子激光建立Ｗｉｓｔａｒ鼠微动脉、微静脉血栓形成模型，对不同剂量阿司匹林对血栓形成的影响进行了研究。发现阿司匹林的抗血栓形成作用与所用剂量密切相关，在超低剂量用药时，呈现出促进血栓形成的作用     

Si1-xGex单晶用热系统改进

阐述了对原GaAs单晶拉制用LEC单晶炉热系统进行改造使其适于Si1-xGex单晶生长的过程。借助数值模拟的方法分析了晶体生长区域内的温度分布情况,并通过分析发现了原有热系统的不足。重新对原热系统进行了改造,添加了起到保温和氩气导流作用的热屏和上保温装置,使原来的敞开式热场变为密闭式热场,满足了SihGe;单晶拉制的要求。通过具体实验和数值模拟结合,分析了氩气流场及不同流场对晶体生长的影响,发现并改进了单晶炉的氩气供给装置存在的问题。     

Influence of argon modified atmosphere packaging on the growth potential of strains of Listeria monocytogenes and Escherichia coli

Modified atmosphere packaging (MAP) based on carbon dioxide (CO₂) – nitrogen (N₂) gas mixtures has been applied to maintain the safety and quality of ready-to-eat (RTE) meat products. The use of argon (Ar) gas as a supplement to CO₂–N₂ mixtures or as substitute for N₂ is a current approach to enhance the effectiveness of MAP. As there is limited information on the effect of Ar MAP on the growth behaviour or the survival of pathogenic bacteria in RTE foods, the aim of the present study was to assess the influence of Ar in MAP on the growth of Listeria monocytogenes and Escherichia coli strains under different conditions. For this purpose, a CO₂–N₂ (20:80) atmosphere was compared with a CO₂–N₂–Ar (30:30:40) and CO₂–Ar (30:70) atmosphere based on the assessment of bacterial growth (δ) on a gelatin-agar medium and ham. Additionally, a shelf life monitoring study was performed to evaluate the effect of these treatments on the background microflora of ham. The findings suggest that under the CO₂–N₂ MAP the product matrices supported the growth (δ > 0.5 log CFU g⁻¹) of L. monocytogenes throughout an observation period of 21 days at 4 ± 2 °C. On the contrary, both MAP containing Ar were equally able to reduce the δ below 0.5 log CFU g⁻¹. In this regard it was irrelevant whether L. monocytogenes was inoculated in depth (per slice) or at the surface (top slice) of the ham. Regarding the influence of the different gas atmospheres on E. coli all gas mixtures applied had the capacity to reduce the δ of E. coli below −0.5 log CFU g⁻¹. Further, shelf-life extension could not be managed with the gas atmospheres considered.     

氩提取率与制氩系统及上塔工况的关系

在空分设备操作时,为提高氩提取率,往往采取加大氩馏分抽取量的方法。结合内压缩流程空分设备,详细分析了氩馏分抽取量过大,对上塔和制氩系统工况的影响;简述了提高氩提取率的正确操作方法。     

Growth of faceted, ballas-like and nanocrystalline diamond films deposited in CH4/H2/Ar MPCVD

The influence of Ar addition to CH₄/H₂ plasma on the crystallinity, morphology and growth rate of the diamond films deposited in MPCVD was investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. X-Ray diffraction patterns indicate that diamond films of strong (111) and weak (400) texture are produced in these samples. Faceted diamond gradually turns into ballas-like diamond with graphitic inclusions when the Ar concentration increases to above 30 vol.%, as indicated by Raman spectra. As the Ar concentration goes above 90 vol.%, nanocrystalline diamond films are formed, characterized by a 1150-cm⁻¹ peak in the Raman spectra and morphology observation. Diamond growth by CH₃ or by C₂ mechanism is proposed to interpret the change in the growth rate of diamond films with the variation of Ar content in the plasma.     

Gas absorption and discharge behaviors of lead-lithium

The absorption of rare gas in the lead-lithium has been quite low and the gas is used as a cover-gas to control the environment of experiment. In our previous thermo-fluid experiment by using lithium-lead, it was found the cover gas pressure enclosed in the very leak tight container of lithium-lead was decreased with time, that is, the gas-absorption of the solid lithium-lead occurred at room temperature under atmospheric pressure. The variation of pressure exceeded the retention of argon in lead-lithium which is expected by the published data. Therefore, we aim to confirm those phenomena under well-controlled experimental condition by using argon, nitrogen and helium. According to the results of gas exposure tests, the absorption of argon in the lead-lithium is comparable with that of helium even at the solid state. For the molten state of lead-lithium, the absorption of argon could be larger than that of helium. It is also observed from the TPD-MS analysis that the argon tends to desorb when the phase change of lead-lithium occurs. If the retention of argon in the lead-lithium cannot be ignored, the problem of Ar-41 activity should be taken into consideration as well as the problem of argon bubble in the lead-lithium.     

Effects of argon and oxygen addition to the CH4-H2 feed gas on diamond synthesis by microwave plasma enhanced chemical vapor deposition

In order to investigate the effects of argon and oxygen on diamond synthesis, the behaviors of diamond deposition using microwave plasma chemical vapor deposition method have been studied by varying the concentrations of argon and oxygen in the methane-hydrogen gas mixture. Diamond films were deposited on silicon wafer under the conditions of substrate temperatures: 1073 1173 K, total reaction pressure: 5333 Pa (40 Torr), methane concentrations: 0.5 5.0%, and they were characterized by scanning electron microscopy, Raman spectroscopy and optical emission spectroscopy. The deposition rates of diamond films were enhanced by adding argon into the methane-hydrogen system, but nondiamond carbon phases in the films also increased. It resulted from the increase of hydrocarbon radicals in the plasma. As oxygen was added, the quality of deposited diamond films was improved due to the decrease of C₂ radicals and increase of OH radicals in the plasma. Simultaneous addition of 0.3% oxygen and 20% argon has been able to effectively suppress the formation of nondiamond carbon components and increase the deposition rate of diamond films. It appears that the ionized argon (Ar⁺) and excited argon atoms (Ar*) may activate the various chemical species and promote the reactions between the gas phase species and oxygen in the plasma.     

43000m~3/h空分设备制氩系统的调试及操作优化

详细叙述兴化43000 m3/h空分设备制氩系统的调试过程。根据空分设备运行数据,结合其内在设计结构,采用边调试、边分析、边优化的方法,完成了制氩系统的调试,并提出了从设计上需对空分设备采取的改进措施。