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481.
Selection and use of autochthonous mixed starter for lactic acid fermentation of carrots, French beans or marrows 总被引:2,自引:0,他引:2
Di Cagno R Surico RF Siragusa S De Angelis M Paradiso A Minervini F De Gara L Gobbetti M 《International journal of food microbiology》2008,127(3):220-228
Strains of Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella soli/Weissella koreensis, Enterococcus faecalis, Pediococcus pentosaceus and Lactobacillus fermentum were identified from raw carrots, French beans and marrows by partial 16S rRNA gene sequence. L. plantarum M1, Leuc. mesenteroides C1 and P. pentosaceus F4 were selected based on the rates of growth and acidification in vegetable juice media, and used as the autochthonous mixed starter for the fermentation of carrots, French beans or marrows. An allochthonous starter, consisting of the same species, was also used for fermentation. A two-step fermentation process (1 day at 25 degrees C and 7 days at 15 degrees C) in brine (1% w/v) followed by storage at room temperature in olive oil until 40 days was set up. Unstarted vegetables subjected to the same treatments were used as the controls. Cell numbers of lactic acid bacteria in the started vegetables were ca. 10,000 (autochthonous starter) and 1000 (allochthonous starter) times higher than unstarted samples throughout the process. When fermented with the autochthonous starter, carrots, French beans or marrows were characterized by the rapid decrease of pH (<4.5), marked consumption of fermentable carbohydrates, and inhibition of Enterobacteriaceae and yeasts. Fermentation with the allochthonous starter did not acidify and inhibit bacteria and yeasts so rapidly. After 40 days, carrots, French beans and marrows fermented with the autochthonous starter had significantly (P<0.05) higher total concentration of vitamin C (ascorbate+dehydroascorbate) with respect to those fermented with the allochthonous starter and, especially unstarted vegetables. The same was found for the indexes of color. Firmness of both started vegetables was higher than unstarted vegetables. Sensory analysis differentiated started vegetables. Carrots and French beans fermented with the autochthonous starter were, especially, appreciated for fragrance. Appearance was the sensory attribute that mainly distinguished marrows fermented with the autochthonous starter. 相似文献
482.
Gibbons Frederick X.; Pomery Elizabeth A.; Gerrard Meg; Sargent James D.; Weng Chih-Yuan; Wills Thomas A.; Kingsbury John; Dal Cin Sonya; Worth Keilah A.; Stoolmiller Mike; Tanski Susanne E.; Yeh Hsiu-Chen 《Canadian Metallurgical Quarterly》2010,24(4):649
Racial differences in the effects of peer and media influence on adolescents' alcohol cognitions and consumption were examined in a large-scale panel study. With regard to peer influence, results from cross-lagged panel analyses indicated that the relation between perceived peer drinking and own drinking was significant for both Black and White adolescents, but it was stronger for the White adolescents. With regard to media influence, structural modeling analyses indicated that exposure to drinking in movies was associated with more alcohol consumption 8 months and 16 months later. These effects were mediated by increases in the favorability of the adolescents' drinker prototypes, their willingness to drink, and their tendency to affiliate with friends who were drinking. Multiple group analyses indicated that, once again, the effects (both direct and indirect) were much stronger for White adolescents than for Black adolescents. The results suggest media influence works in a similar manner to social influence and that Whites may be more susceptible to both types of influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
483.
The aim of this study was to investigate the role of nitric oxide in metabolic disturbances induced in brain tissue of fetal guinea pigs by oxygen-glucose deprivation. Experiments were performed on hippocampal slices so as to exclude the effects of nitric oxide on the cardiovascular system. Metabolic disturbances were assessed by measuring changes in energy metabolism and protein synthesis after different periods of oxygen-glucose deprivation (OGD). Ten min after OGD of 40 min duration, the concentration of cGMP in tissue slices rose from 1.35 +/- 0.38 to 18.6 +/- 1.04 pmol/mg protein (P < 0.05). This rise was almost completely inhibited by the addition of 100 microM N-nitro-L-arginine (NNLA), indicating that NO-synthase was strongly activated after OGD in fetal brain tissue. However, addition of NNLA improved neither protein synthesis nor energy metabolism measured 12 h after OGD. Thus, nitric oxide does not appear to contribute directly to processes leading to metabolic disturbances induced by transient ischemia in immature brain tissue. 相似文献
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Stochastic ray tracing is one of the most elegant methods for anti-aliasing and for generating such phenomena as soft shadows, fuzzy reflections, depth of field, and motion blur, which are difficult to accomplish with the conventional ray-tracing algorithm. Unfortunately, it makes use of stochastic sampling, which requires more than one sample for each pixel. One possible way to speed up ray tracing is to explore the inherent parallelism of the algorithm. In the past few years, the major focus of parallel ray-tracing research has been on the use of MIMD architectures. Although SIMD architectures may be ideal for ray tracing simple scenes, they have been thought unsuitable for ray tracing complex scenes. However, by using scene coherence, we have found that stochastic ray tracing using SIMD processor arrays can be as efficient as most of the existing MIMD ray-tracing algorithms and more cost effective. 相似文献
487.
488.
Mel Slater 《The Visual computer》1992,9(1):39-46
Finding the cells intersected by a ray in a uniformly subdivided space is a technique used in accelerated ray tracing and also other computer graphics applications. A related problem is that of finding the sequence of grid points in a 3D voxel space, which best approximates a given line. This paper examines earch of these problems, introduces a unifying approach and provides a generalisation of previous algorithms.Written while on sabbatical leave from Department of Computer Science, QMW University of London, Mile End Road, London E1 4NS, UK 相似文献
489.
CH Cantor AA Leenaars D Lester PJ Slater AM Wolanowski B O'Toole 《Canadian Metallurgical Quarterly》1996,31(6):364-373
Suicide rates between 1960 and 1989 were explored for eight predominantly English speaking countries with similar national characteristics. New World countries showed significant similarities but differed from Old World countries. The two North American (NA) New World countries showed more similarity to each other than the two Australasian New World countries. The NA countries showed an unique plateau in the 1980s for males aged 15-29 years. Old World males of all ages showed common rises, suggesting a partial sex-specific influence in the young. However, trends among the 15- to 19-year-olds were significantly different to trends among the 20- to 29-year-olds in both sexes suggesting a substantial youth-related contribution to the rises. Rates among 15- to 19-year-old females rose in the early 1960s, ahead of males but in parallel with rises among older females, suggesting part of the rise was sex- as opposed to age-related. Although rates among the 15- to 19-year-old females showed little change since 1970, this may be partly a function of sex-related improvements-observable in older females disguising unfavourable youth-related influences. Possible aetiological factors are suggested but remain speculative. Studies of other nations with common cultural characteristics may clarify trends and aetiological issues. Care should be taken to differentiate sex- from age-related influences. 相似文献
490.