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81.
In computer and electronic manufacturing, it is very important to be able to automatically check whether the surface mounted devices (SMD) are correctly placed on the printed circuit boards. The inspection of these boards has to be done on a shop floor, where statistical characteristics of the noise vary so much that, in essence, we only have interval estimates for this noise.We show that under this interval uncertainty, the optimal image processing technique consists of using Haar wavelets. Wavelets indeed lead to much better results than previously used Fourier transform techniques.On a more fundamental level, our result is a step towards solving an important problem related to wavelets: that wavelet transforms often empirically work much better than other methods, but there are very few theoretical explanations of this efficiency. Our results shows that, probably, such a theoretical explanation can be obtained if we take interval uncertainty into consideration. 相似文献
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Koji Watari Maria Cecilia Valecillos Manuel E. Brito Motohiro Toriyama Shuzo Kanzaki 《Journal of the American Ceramic Society》1996,79(12):3103-3108
Small amounts of Li2 O result in sintering in the AIN-Y2 O3 -CaO and AIN-CaO systems at firing temperatures <1600°C. The effect is ascribed to reduction of the liquidus temperature. Furthermore, Li2 O is removed by volatization at temperatures from 1300° to 1600°C, and its content decreases several ppm from the initial 0.3 wt%. Li2 O-doped AIN specimens containing Y2 O3 and CaO additives are well densified by firing at 1600°C for 6 h, and their thermal conductivity is 135 W. m−1. K−1 .The effect of Li2 O addition on sintering and thermal conductivity also is discussed through thermo-dynamic considerations. 相似文献
84.
JM Koelman HJ Noteborn de Goey LP BJ Verhaar JT Walraven 《Canadian Metallurgical Quarterly》1985,32(11):7195-7198
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Analysis of amino acids is complicated by treatment with ampicillin. High voltage electrophoresis, which is convenient for the qualitative assessment of metabolic diseases, yields smears of ampicillin that mask the bands of citrulline, homocitrulline, phenylalanine, cystine, and homocystine. The addition of penicillinase prior to high voltage electrophoresis eliminates ampicillin and other penicillins and reveals these key amino acids. 相似文献
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SUMMARY Poly(amide-ester)s, poly(amide-carbonate)s and poly(amide-thiocarbonate)s derived from the diphenols-amides N-(2,6-dibromo-4-nitrophenyl)-4,4-bis(4-hydroxyphenyl)-pentanamide (I) and N-(2,6-diiodo-4-nitrophenyl)-4,4-bis(4-hydroxyphenyl)-pentanamide (II) and terephthaloyl chloride (a), isophthaloyl chloride (b), and adipoyl chloride (c), and phosgene (d) and thiophosgene (e) respectively, have been synthesized under phase transfer conditions using several quaternary ammonium salts as phase transfer catalysts. Benzyltriethylammonium chloride (BTEAC) was effective in practically all cases due to the hydrophilicity of this catalyst. Poly(amido-ester)s derived from II and aromatic diacids were insoluble in all the organic solvents, and the effectivity of the process was evaluated by the increase of the yields with respect to the essays without catalysts. Received: 26 January 1999/Revised version: 17 May 1999/Accepted: 17 May 1999 相似文献
90.
Eight ruminally cannulated Holstein cows that were part of a larger lactation trial were used in 2 replicated 4 × 4 Latin squares to quantify effects of supplementing protein as urea, solvent soybean meal (SSBM), cottonseed meal (CSM), or canola meal (CM) on omasal nutrient flows and microbial protein synthesis. All diets contained (% of dry matter) 21% alfalfa silage and 35% corn silage plus 1) 2% urea plus 41% high-moisture shelled corn (HMSC), 2) 12% SSBM plus 31% HMSC, 3) 14% CSM plus 29% HMSC, or 4) 16% CM plus 27% HMSC. Crude protein was equal across diets, averaging 16.6%. The CSM diet supplied the least rumen-degraded protein and the most rumen-undegraded protein. Microbial nonammonia N flow was similar among the true protein supplements but was 14% lower in cows fed urea. In vivo ruminal passage rate, degradation rate, and estimated escape for the 3 true proteins were, respectively, 0.044/h, 0.105/h, and 29% for SSBM; 0.051/h, 0.050/h, and 51% for CSM; and 0.039/h, 0.081/h, and 34% for CM. This indicated that CSM protein was less degraded because of both a faster passage rate and slower degradation rate. Omasal flow of individual AA, branched-chain AA, essential AA, nonessential AA, and total AA all were lower in cows fed urea compared with one of the true protein supplements. Among the 3 diets supplemented with true protein, omasal flow of Arg was greatest on CSM, and omasal flow of His was greatest on CSM, intermediate on CM, and lowest on SSBM. Lower flows of AA and microbial nonammonia N explained lower yields of milk yield and milk components observed on the urea diet in the companion lactation trial. These results clearly showed that supplementation with true protein was necessary to obtain sufficient microbial protein and rumen-undegraded protein to meet the metabolizable AA requirements of high-producing dairy cows. 相似文献