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961.
In this paper, a new Chinese character recognition (CCR) approach is proposed based on the fuzzy clustering analysis theory. Chinese characters (CCs) have various similar radicals and stroke components, which make it difficult to recognize features in the CCR process. At the same time, the recognition accuracy and the efficiency are lower when the objects to be recognized are complex. In order to solve these problems, a fuzzy clustering analysis method is introduced to enhance the computing efficiency. At first, the CCs including learning samples and testing samples are transformed into binarization templates in the form of matrixes. Then, the minimum distance algorithm is applied to calculate ‘distances’ between the testing sample templates and the learning sample templates. At last, the character recognition can be achieved by searching the minimum distance from the results. The experiment results of the CCR process can prove the effectiveness and accuracy of the new method. 相似文献
962.
R. E. F. Einerhand W. H. M. Visscher E. Barendrecht 《Journal of Applied Electrochemistry》1988,18(6):799-806
The determination of the amount of hydrogen produced during the electrodeposition of zinc from alkaline zincate solutions was carried out using the rotating ring-disc electrode (RRDE) technique. The experimental conditions for which the RRDE technique offers reliable results are discussed. Hydrogen production during zinc deposition was studied for a range of cathodic (disc) current densities (20–500 A m–2) and electrolyte compositions (1–7 M KOH, 0.01–0.2 M zincate). It was found that an increasing amount of hydrogen was formed with increasing (disc) current density and decreasing KOH and zincate concentration. The impact of hydrogen formation during the charging process on nickel oxide/zinc secondary battery performance is expected to be small. It is concluded that in battery electrolytes (8 M KOH, 1 M zincate) hydrogen is formed chiefly by corrosion of the zinc electrode rather than by electrochemical formation during the electrochemical reduction of zinc. 相似文献
963.
The role of Zn atmosphere on the microstructure development of Mn-Zn ferrite prepared by alcholic dehydration was investigated. Discontinuous grain growth and intragranular porosity were observed throughout the specimen when a low oxygen partial pressure was employed during sintering. The microstructure of Mn-Zn ferrite sintered in air resembled a mixture between Mn ferrite (uniform grain size) and Zn ferrite (exaggerated grain growth). Exaggerated grain growth was also observed on the surface of Mn ferrite sintered in the presence of a Zn-rich atmosphere. The presence of Zn vapor phase enhanced the grain growth kinetics. The overall results indicate that a strict control of atmosphere is required in order to achieve a uniform pore-free microstructure. 相似文献
964.
Cysteine reacts with linoleic acid hydroperoxide to yield several products, some of which were identified as fatty acid-cysteine
adducts. The addition was catalyzed by ferric chloride (10−5 M) by initiating free radical reactions. When isomerically pure 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid and cysteine were reacted in 80% ethanol under N2, the major adducts were 9-S-cysteine-13-hydroxy-10-ethoxy-trans-11-octadecenoic acid (I) and 9-S-cysteine-10,13-dihydroxy-trans-11-octadecenoic acid (II). When the reaction included both isomers of the hydroperoxide (13-and 9-hydroperoxide) and air,
an adduct of 9-oxononanoic acid and cysteine also was isolated. Additional experiments gave information about possible mechanisms
of I and II formation. 相似文献
965.
A factorial design experiment was conducted to determine the major parameters affecting the densification of mixtures having the composition (in mol%) 50 Si3 N4 , 25 A12 O3 , and 25 A1N. Improved densities of the resulting sialon were achieved using a longer milling time and SN-502 Si3 N4 powder. However, sialon samples prepared from the SN-502 powder contained some of the X-phase, whereas those fabricated from AME Si3 N4 powder did not. This difference is considered to be due to the higher SiO2 content of the SN-502 powder and its greater susceptibility to partial hydrolysis during the milling process. Reaction-sintered sialon (97.2% theoretical density) fabricated using AME powder had a room-temperature bend strength of 352
MN/m2 (51,000 psi) and exhibited slow crack growth at 1300° and 1400°C. It is suggested that this is not an inherent property of sialon but is due to the presence of a calcium-containing grain-boundary phase, as in hot-pressed Si3 N4 . 相似文献
MN/m
966.
Modified sets of response equations have been derived for a single inclined hot-wire probe introduced in various orientations in a flow field having a dominant tangential velocity component. By means of these equations, the components of the three dimensional mean velocity vectors, the turbulence intensity and the Reynolds stresses can be easily determined at any location in a swirling flow which is stationary with time. This method is particularly applicable to the characterization of the flow field in chemical processing equipment where this type of swirling flow is increasingly being used. It has been successfully applied to a study of the flow field in a spray-drying chamber, in the course of which good reproducibility and consistency of results were obtained. 相似文献
967.
968.
969.
T.M. Egelkraut D.E. Kissel M.L. Cabrera W. Adkins 《Nutrient Cycling in Agroecosystems》2003,66(1):1-12
The N mineralized from soil organic matter provides an important portion of N available for crop production. The objective of this study was to determine the amount of spatial variability in N mineralization potential in a field and to evaluate three different methods that might be used to estimate this variability. The three methods tested included predicting the N mineralized from surface soil properties as well as from a biological and a chemical procedure. Three soils varying in N mineralization potential were selected for the study from a field in the Georgia Coastal Plain. The N mineralized from these soils was determined by an N balance of unfertilized and cropped plots. The amount of N mineralized could not be reliably predicted from surface soil organic C, although surface soil clay concentration was positively correlated with the N mineralized. The N mineralized that was predicted using mineralization parameters determined by aerobic incubation, adjusted daily for soil water content and temperature, was approximately 50% of the field measurements of N mineralized. The values of NH4-N extracted with hot 2 M KCl were related significantly to N mineralized in the field (r2= 0.60) and also to the zero order rate constant of mineralization, k0 (r2= 0.77), determined from the N mineralized in the aerobic laboratory incubation. 相似文献
970.
Fatigue crack propagation (FCP) tests were conducted at various frequencies on nylon-6,6 specimens equilibrated over a range of moisture levels to determine the crack growth rates and the crack-tip temperatures as a function of water content. Frequency-sensitivity was correlated with the amount of crack-tip heating taking place, with crack-tip temperature being found to depend strongly on the estimated loss compliance, D″, of the material. The frequency-sensitivity of FCP in nylon was seen also to be affected by mean stress, suggesting that creep processes are often significant in FCP of nylon. 相似文献