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The quality of a sanded wood surface is represented by its roughness, which can be separated from the originally measured data by a procedure of filtering. Past experience has shown that the robust Gaussian regression filter (RGRF) is suitable for wood surfaces because it does not introduce distortions into the roughness profiles. The filter works iteratively until a user-defined convergence condition is met. The iterations stop when the difference between two consecutive profile median values becomes smaller than a given tolerance. This paper examines the convergence of RGRF when applied to wood surfaces sanded with various grit sizes in order to establish the tolerance value, which leads to convergence with the minimum number of iterations. This study was based on monitoring the variation of roughness parameters with the number of iterations for a range of tolerance values. A tolerance of 0.01 μm was found acceptable for filtering sanded wood surfaces. 相似文献
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Bovine tuberculosis (TB) causes severe economic losses in livestock due to low production, animal deaths and condemnation of carcasses. It is also an important constraint in international trade of animals and animal products. A scientific committee in Great Britain in 1997 concluded that the development of a cattle vaccine would be the best option for long-term control of TB. However, vaccination of cattle currently is not accepted because the vaccine interferes with the skin reaction to the tuberculin test in the field. Efficacy of M. bovis BCG in protecting bovine and other animal species against tuberculous infection has received much study. Vaccination of cattle prevents the spread of the disease in populations by reducing the number and size of the lesions, and the load of bacteria (rather than by preventing infection). We review the literature about the efficacy of BCG in protecting cattle and other animal species against infection with field strains of M. bovis and discusses its potential use in programs of TB control in high-prevalence populations. 相似文献
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Zenovia Olteanu Elena Truta Stefania Surdu Ciprian Manzu Gurau Milian Craita Rosu Titu Zamfirache 梁月 《国际沙棘研究与开发》2010,8(3):45-48
沙棘（Hippophae rhamnoides）是一种可广泛生长于欧亚地区,包括罗马尼亚的小果实灌木。沙棘具有药用及营养价值,同时可以改善区域的微气候环境。人们已经研究了罗马尼亚沙棘的生物化学组分及相关数据,所以我们分析了不同沙棘叶的甘树脂,一个重要的生化参数可以为植株的一项基本新陈代谢——光合作用提供信息。结果表明根据品种及特定环境因素的不同,产生了多样性。 相似文献
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E Reddington A Sapienza B Gurau R Viswanathan S Sarangapani ES Smotkin TE Mallouk 《Science (New York, N.Y.)》1998,280(5370):1735-1737
Combinatorial screening of electrochemical catalysts by current-voltage methods can be unwieldy for large sample sizes. By converting the ions generated in an electrochemical half-cell reaction to a fluorescence signal, the most active compositions in a large electrode array have been identified. A fluorescent acid-base indicator was used to image high concentrations of hydrogen ions, which were generated in the electrooxidation of methanol. A 645-member electrode array containing five elements (platinum, ruthenium, osmium, iridium, and rhodium), 80 binary, 280 ternary, and 280 quaternary combinations was screened to identify the most active regions of phase space. Subsequent "zoom" screens pinpointed several very active compositions, some in ternary and quaternary regions that were bounded by rather inactive binaries. The best catalyst, platinum(44)/ruthenium(41)/osmium(10)/iridium(5) (numbers in parentheses are atomic percent), was significantly more active than platinum(50)/ruthenium(50) in a direct methanol fuel cell operating at 60 degreesC, even though the latter catalyst had about twice the surface area of the former. 相似文献
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