恶劣条件下直流变频压缩机润滑油位变化的实验研究

针对直流变频自由拖5 HP外机进行实验,以四台低静压风管机室内机为实验对象,在各种恶劣工况条件下研究润滑油变化时,系统应采取何种相应控制手段,并从系统控制方面进行精细的设计,确保直流变频压缩机润滑油的可靠性。     

1400mm轧机工艺润滑油中添加剂的测定

在有色金属加工中，工艺润滑油中添加剂的含量与产品质量密切相关。采用高氯酸催化乙酸酐乙酰化法可准确测定轧铝油中添加剂的浓度，此方法在较低温度下进行，速度快，可满足轧机轧制油添加剂的工业分析。     

Nonverbal Communication and Foreign Language Teaching

Ⅰ　　Ｃｏｍｍｕｎｉｃａｔｉｏｎｉｓｎｏｔａｎｏｂｊｅｃｔｗｅｃａｎｈｏｌｄｉｎｏｕｒｈａｎｄ -ｉｔｉｓａｎａｃｔｉｖｉｔｙｉｎｗｈｉｃｈｗｅｐａｒｔｉｃｉｐａｔｅ (Ｐｅａｒｓｏｎ ,1991) .Ｃｏｍｍｕｎｉ ｃａｔｉｏｎｉｓｕｓｕａｌｌｙｄｅｖｉｄｅｄｉｎｔｏｔｗｏｐｒｉｍａｒｙｃａｔｅｇｏｒｉｅｓ :ｖｅｒｂａｌａｎｄｎｏｎｖｅｒｂａｌ(Ｂｒｏｏｋｓ ,1974 )ｉｎｔｅｒｍｓｏｆｉｔｓｅｌｅｍｅｎｔｓ.Ｖｅｒｂａｌｃｏｍｍｕ ｎｉｃａｔｉｏｎ(ＶＣ)ｍｅａｎｓｃｏｍｍｕｎｉｃａｔｉｏｎｗｉｔｈｌａｎｇｕａｇ…     

Disfiguring organic residues on industrially produced sheet metal coupons simulating copper and brass works of art by Donald Judd: Attenuated total reflectance Fourier transform infrared spectroscopy analysis and treatment recommendations

Abstract

The Minimalist work of Donald Judd exemplifies modern and contemporary works of art that utilize the appearance of bare metal as an integral component of the artist's intent. Decades after fabrication, disfiguring patterns have appeared on the surfaces of many such works. These patterns are not related to the formation of tarnish or other corrosion effects caused by improper storage, display, or transportation and handling; rather, they are associated with the initial processing of the metal sheets and subsequent fabrication of the art objects. Due to the challenges of obtaining analytical data directly from works of art, the authors present results from industrial sheet metal coupons prepared to simulate materials and techniques used in Donald Judd's copper and brass artworks. Attenuated total reflectance Fourier transform infrared spectroscopy carried out on each side of 55 coupons indicated the presence of organic materials such as long-chain aliphatic hydrocarbons, esters, and ethers, consistent with the types of compounds used in industrial lubricants. In addition to conducting the first systematic instrumental analysis of these residues, the authors propose the use of specific solvents for their removal as an alternative to abrasive methods, which cause removal of original surface from the objects.     

金属切削机床润滑油的使用期限

对润滑油在金属切削机床的使用期限进行检测对比发现,润滑油的质量按油中金属杂质的含量确定,机床各机构的技术状况根据机构的实际状况以及油中金属杂质含量的变化作出评价。润滑油中金属杂质的含量对不同型号的机床是不一样的,它取决于注入润滑油系统的油量V和变速箱齿轮的总齿数Z。对于被测定的各种型号的机床,Z/V的比值是一定的。试验结果表明,对被试验的各型普通机床,与现行标准比较,润滑油的使用期限可增加一倍。     

A study of stearyl alcohol bloom on Dan Hill PVC dolls and the influence of temperature

A study was conducted to investigate white bloom found on more than 130 polyvinyl chloride (PVC) dolls from the 1980s and 1990s produced by the Danish factory Dan Hill Plast A/S. The bloom was discovered on the dolls after 10 years of storage in a climate controlled facility with average temperature at 11–12°C and a relative humidity at 50?±?5%. Analysis of the dolls and the bloom was carried out using Fourier transform infrared spectroscopy, which revealed that the bloom consisted primarily of stearyl alcohol. Subsequent analysis with gas chromatography–mass spectrometry showed a minor presence of cetyl alcohol. It is proposed that the alcohol had been added as a lubricant to aid flow during processing. The stearyl alcohol was almost completely reabsorbed into the PVC dolls following one month storage at room temperature, suggesting that low temperature storage played a decisive role in the appearance of the bloom. It is likely that a decrease in temperature has led to a decrease in compatibility of the stearyl alcohol in the PVC compound, thus promoting its exudation. This paper also discusses an extreme bloom of white crystals on other PVC dolls of unknown provenance.