首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2324篇
  免费   455篇
  国内免费   4篇
综合类   34篇
化学工业   115篇
机械仪表   5篇
建筑科学   3篇
能源动力   3篇
轻工业   2597篇
石油天然气   13篇
无线电   2篇
一般工业技术   6篇
冶金工业   1篇
原子能技术   3篇
自动化技术   1篇
  2025年   27篇
  2024年   81篇
  2023年   77篇
  2022年   136篇
  2021年   147篇
  2020年   164篇
  2019年   156篇
  2018年   108篇
  2017年   137篇
  2016年   123篇
  2015年   84篇
  2014年   113篇
  2013年   155篇
  2012年   203篇
  2011年   195篇
  2010年   138篇
  2009年   107篇
  2008年   104篇
  2007年   118篇
  2006年   110篇
  2005年   72篇
  2004年   60篇
  2003年   43篇
  2002年   31篇
  2001年   21篇
  2000年   8篇
  1999年   11篇
  1998年   8篇
  1997年   7篇
  1996年   3篇
  1995年   3篇
  1994年   2篇
  1993年   4篇
  1992年   8篇
  1991年   5篇
  1989年   2篇
  1987年   1篇
  1983年   1篇
  1981年   1篇
  1980年   6篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有2783条查询结果,搜索用时 0 毫秒
1.
 The reasons for using lactic acid bacteria are to make food durable, to improve its taste and to maintain the nutritive, physiological and hygienic value of the fermentation products. Sixteen strains of the genus Lactobacillus were tested on samples of white fresh cabbage and of a sterilized cabbage and carrot juice mixture. After 7 days of lactic acid fermentation at 27  °C or 30  °C, reducing sugars, total acidity, pH value, lactic, citric and acetic acids, ammonia, nitrates and nitrites were measured in the samples. On the basis of the criteria mentioned above three strains were acceptable. These strains reduced the content of nitrates in the original samples. Received: 14 December 1998 / Revised version: 18 March 1999  相似文献   
2.
The ability of Lactobacillus plantarum ATCC 8014 to inhibit Clostridium botulinum toxin production in pea soup was investigated. Soup containing C. botulinum spores (103/g) with and without L. plantarum (106/g) were evaluated. Soup containing only type A spores was toxic on days 1 and 2 when incubated at 35°C and 25°C, respectively. Soup containing only proteolytic type B spores was toxic on days 2 and 5 at 35°C and 25°C, respectively. Soup containing only type E spores was toxic at 25°C, 15°C, and 5°C in 7, 7, and 63 days respectively. No toxin was found in soup containing C. botulinum spores plus L. plantarum at any temperature studied.  相似文献   
3.
乳酸菌在食品工业中的应用   总被引:1,自引:0,他引:1  
乳酸菌是应用于食品工业的重要菌种,阐述了乳酸菌的基本特征和分类,综述了其在乳制品、植物蛋白饮料、蔬菜深加工、肉制品生产、食品防腐及保鲜方面的应用,并对乳酸菌的应用前景进行了展望。  相似文献   
4.
Some Lactobacillus delbrueckii ssp. bulgaricus strains are able to synthesize exopolysaccharides (EPS) and are therefore highly important for the dairy industry as starter cultures. The aim of this study was to investigate the nutritional requirements for growth and EPS production of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081. A medium was developed from a semi-defined medium (SDM) in which glucose was replaced by lactose and different combinations of supplements (nucleobases, vitamins, salts, sodium formate and orotic acid) were added. Constant pH batch fermentation with the modified medium resulted in an EPS yield of approximately 210 mg glucose equivalents per liter medium. This was a 10-fold increase over flask cultivation of this strain in SDM. Although not affecting cell growth, the mixture of salts enhanced the EPS synthesis. Whereas EPS production was approximately 12 mg/g dry biomass without salt supplementation, a significantly higher yield (approximately 20 mg/g dry biomass) was observed after adding the salt mixture. In continuous fermentation, a maximal EPS concentration was obtained at a dilution rate of 0.31/h (80 mg EPS/L), which corresponded to a specific EPS production of 49 mg/g dry biomass.  相似文献   
5.
研究了预培养对酸奶冻干发酵剂活力的影响。在不同的温度和时间下,对酸奶冻干发酵剂的悬浮液进行预培养,得出当温度为42℃时培养40min,冻干发酵剂菌体存活率可以从71%提高到82%,凝乳时间可以从210min降低到185min。在4℃经90d贮藏稳定性实验,发酵剂中菌种的存活率为62%,凝乳时间为245man,较对照存活率提高了23%,凝乳时间缩短了45min。  相似文献   
6.
Organic waste generated from industrial sweet potato canning is estimated to be 30% of incoming raw material with significant residual carbohydrate content. The purpose of this study was to evaluate the potential of waste generated from sweet potato processing material to support the growth of lactic acid bacteria and the production of lactic acid. The waste was comprised of 16.5% solids consisting of 18.5% ash, 4.4% protein, 20.5% simple sugars and 19% soluble starch. Following a screening of three lactic acid bacteria strains, Lactobacillus rhamnosus was deemed the best candidate for lactic acid production. The potential of various dilutions of the enzyme‐hydrolysed waste, with and without pH control, as a fermentation substrate was evaluated. Lactic acid production was highest in hydrolysed waste (without dilution) at pH set point 5.0, yielding 10 g L?1 in 72 h. Thus, lactic acid, a valuable organic compound, can be generated from sweet potato waste.  相似文献   
7.
以5株德氏乳杆菌保加利亚亚种为出发菌株,详细研究了5株菌的生长代谢、酸敏感性及蛋白水解力,并分析了这些特性与后酸化之间的关系。结果表明:5株菌的生长性能与后酸化之间存在紧密联系。其中,菌株的生长速度和糖分解代谢能力与后酸化成正比;对酸较敏感菌株的后酸化也较弱;菌株的蛋白水解能力与生长速度和后酸化之间没有明显的相关性。  相似文献   
8.
采用正交试验研究了保加利亚乳杆菌在冷冻干燥条件下的最佳保护剂的筛选。结果表明:在所选的冷冻干燥保护剂中,VC影响极显著,脱脂乳和谷氨酸钠影响显著,明胶影响不显著;筛选出最佳复合保护刑组成为脱脂乳10%、VC0.5%、谷氨酸钠0.5%、明胶1.5%。  相似文献   
9.
10.
The use of recombinant aminopeptidase (PepN) from Lactobacillus rhamnosus S93 in free or encapsulated form was investigated to shorten the duration of Cheddar cheese ripening. Proteolysis was determined by measuring the soluble nitrogen as phosphotungstic acid (PTA-N) derivatives and free amino acids (FAA) over a 6-month period. The experimental cheeses received higher scores for sensory properties than the control cheese. The amounts of PTA-N and total FAA in the cheese with the encapsulated enzyme after 2 months of ripening were close to those of the control cheese after 6 months, suggesting the acceleration in proteolysis by about 4 months.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号