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131.
The effect of inorganic surface treatments on the orientation of lithium disilicate crystals formed in Li2O·2.75SiO2 glass fibers was studied. Glass fibers 0.5 mm and 9μ in diameter were subjected to various surface treatments at room temperature and then heated between 550O and 800°C. It was observed that metal salt solutions applied to the fiber surfaces at room temperature decreased the degree of orientation during heating only if the metal entered the glass and formed nucleation sites within the fibers. Orientation could also be decreased by removing lithium from the glass surfaces. Comparison of the crystallization characteristics of untreated and AgNO3-treated fibers indicated that the crystallization behavior was controlled by either a growth process or a nucleation process, depending on whether the temperature was below or above 625°, respectively.  相似文献   
132.
Fracture Toughness Determinations by Indentation   总被引:13,自引:0,他引:13  
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133.
Whole, abrasion-pecled Russet Burbank potatoes were dipped in a solution containing 3% D-araboascorbic acid (erythorbic acid), 0.25% sodium acid pyrophosphate and 2% sodium chloride or water. They were drained and packed in 0.2% citric acid, 0.2% sorbic acid and 0.25% calcium chloride or water, sealed in plastic bags and stored at 3.8°C. Potatoes packed in the citric acid mixtures maintained a lower microbial load after 6 days storage when compared to bisulfite-treated or water-dipped potatoes. All potatoes maintained acceptable color through 18 days storage. Treatments did not alter shear force measurements of raw, peeled potatoes or perceived flavor and texture of cooked, mashed potatoes.  相似文献   
134.
The interfacing of computer-aided design (CAD) to computer-aided manufacturing (CAM) is a vital step in automated manufacturing. An essential operation is the recognition of features from the part design. This paper presents a methodology for the recognition of features from two-dimensional rotational objects. First, this work defines the term ‘feature’ as a set of connected lines in the profile of the object, which satisfy certain geometric properties. Then, the task of feature recognition is decomposed into a set of distinct functions. These recognize, classify, decompose and reconstruct, and identify face sets which satisfy the definition of features. A prototype is developed which implements these functions. The important characteristics of this methodology are: (1) all cylindrical features are recognized, and most of them identified according to the input formats of a desired CAPP system; and (2) the system is modular and flexible and its functions can be easily modified.  相似文献   
135.
基于天然砂分计筛余百分率,采用再生细骨料按照0~0.315 mm、0~0.63 mm、0~1.25 mm、0~2.5 mm和0~5.0 mm不同粒级逐级取代天然砂制作再生砂浆,测定其在0.55、0.60、0.65水灰比下7d、14d和28 d的抗折抗压强度和微观形貌.试验结果表明:再生砂浆试件的抗折抗压强度均大于空白试件,且随着再生细骨料逐级取代率的提高而增大;当再生细骨料100%逐级取代天然砂时,龄期为14 d时的再生砂浆的强度增长最大;28 d时,再生砂浆抗压强度的降低幅度随着水灰比的增加而增加,但抗折强度的降低幅度却随着水灰比的增加而减小;随水化龄期的增加,再生砂浆中水化产物不断增多,界面过渡区越来越密实.  相似文献   
136.
137.
An ethanolic extract of Cranberry exerted a significant antimicrobial effect on Saccharomyces bayanus and Pseudomonas fluorescens. The antimicrobial properties of cranberries were due to a number of factors. First, the low pH (2.6) inhibited many microorganisms per se, and its effect on the dissociation of benzoic acid made the inhibition more drastic. Secondly, after raising the pH to 5.2, cranberry juice still did not support the growth of S. bayanus. Growth did occur at pH 5.2 after 0.3% yeast nitrogen base was added. Thirdly, proanthocyanidins and flavonols were found to be the major microbial inhibitors other than benzoic acid. The results showed that proanthocyanidins provided 21.3% of the inhibition, the flavonols 18.5% and benzoic acid 15.6%.  相似文献   
138.
A single layer higher order dynamic topology neural net called HODYNE is described, targeted at natural language processing problems, HODYNE has an input layer of nodes containing concatenations of words from the input string, and grows nodes during training which are dependent on the training data. The training procedure also has some novel features. Results are presented on the problem of grammaticality determination. The results are encouraging, with almost perfect performance on unseen test sets derived from simple context-free grammars. An important aspect of this work is that the data sets used in training and testing are larger than is common in the research literature.  相似文献   
139.
Ground turkey breast and thigh muscle were extracted with various NaCl solutions with or without added CaCl2, MgCl2, or ZnCl2 (0.05%). Protein solubility was increased by CaCl2 and decreased by ZnCl2 in each muscle type. At 4% NaCl, MgCl2 increased thigh myosin solubility by 30%, compared to the control, whereas CaCl2 had no effect. At 2% and 4% NaCl, breast myosin was not affected by MgCl2 or CaCl2. Myosin was not detected for either muscle type when ZnCl2 was used. All three salts increased breast actin solubility but only MgCl2 increased thigh actin solubility. The CaCl2 resulted in the highest overall protein solubility and MgCl2 resulted in the highest thigh myosin and actin solubility at 4% NaCl.  相似文献   
140.
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