全文获取类型
收费全文 | 2076篇 |
免费 | 102篇 |
国内免费 | 1篇 |
出版年
2023年 | 3篇 |
2021年 | 20篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 23篇 |
2017年 | 29篇 |
2016年 | 29篇 |
2015年 | 53篇 |
2014年 | 94篇 |
2013年 | 162篇 |
2012年 | 113篇 |
2011年 | 131篇 |
2010年 | 93篇 |
2009年 | 69篇 |
2008年 | 106篇 |
2007年 | 153篇 |
2006年 | 138篇 |
2005年 | 122篇 |
2004年 | 171篇 |
2003年 | 132篇 |
2002年 | 150篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 28篇 |
1998年 | 34篇 |
1997年 | 28篇 |
1996年 | 17篇 |
1995年 | 22篇 |
1994年 | 26篇 |
1993年 | 25篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 16篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1969年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有2179条查询结果,搜索用时 203 毫秒
991.
Masao Kanamori Fumio Ibuki Masaaki Yamada Misao Tashiro Masamitsu Miyoshi 《Bioscience, biotechnology, and biochemistry》2013,77(5):839-844
The dialyzable proteinase inhibitor in the exocarp of the eggplant, Solanum melongena L. was partially purified by column chromatographies on DEAE-cellulose and Sephadex G–25. The inhibitor showed strong inhibitory activity on bovine trypsin [EC 3.4.4.4], Pronase and Nagarse. It also weakly inhibited α-chymotrypsin [EC 3.4.4.5], but, pepsin was not affected. The presence of three inhibitors in this preparation was demonstrated by isoelectrofocusing; their isoelectric points being pH 4.2, 4.7 and 6.3. The inhibitor with a pI value of 4.7 was present significantly more than the others. The molecular weight of the inhibitor was 5300 based on Sephadex G–75 gel filtration data. It was also very stable to heat treatment. This inhibitor was not the multi-headed type, and was gradually inactivated after a 4 hr incubation with Pronase. 相似文献
992.
Masatoshi Maki Masatsugu Ueda Masaaki Hirose Hideo Chiba 《Bioscience, biotechnology, and biochemistry》2013,77(7):1979-1981
Fumes from phospholipids pyrolyzed at 500~700°C did not themselves show any mutagenicity on Salmonella strains, but when the pyrolyzates were treated with a sodium chloride precipitate, active carbon, or an anionic exchange resin, the filtrates were found to be mutagenic on Salmonella TA 100. Tests confirmed that the phospholipid pyrolyzates contained both mutagenic and inactivating substances of this mutagenicity. Low level mutagenicity was produced on Salmonella TA 98, but there was no such activity on the other strains. Preincubation of the pyrolyzates with S-9 mix had no activating effect on mutagenicity. The inactivating substances of the mutagenicity were isolated and identified as long chain fatty acids. 相似文献
993.
(±) -trans-2,2-Dimethyl-3- (2′-methyl-2′-propenyl) cyclopropan-l-carboxylic acid (VII) was obtained by the treatment of (±) -pyrocin (IV) with thionyl chloride and absolute ethanol saturated with dry hydrogen chloride followed by the cyclization action of sodium tert-amylate in dry benzene and alkaline hydrolysis. This was converted into (±) -trans-chrysanthemic acid (VIII) by the catalytic action of p-toluenesulfonic acid. 相似文献
994.
995.
Masaaki Konishi Naruyuki Maruoka Yoshifumi Furuta Tomotake Morita Tokuma Fukuoka Tomohiro Imura 《Bioscience, biotechnology, and biochemistry》2013,77(3):516-523
The isolation of biosurfactant-producing yeasts from food materials was accomplished. By a combination of a new drop collapse method and thin-layer chromatography, 48 strains were selected as glycolipid biosurfactant producers from 347 strains, which were randomly isolated from various vegetables and fruits. Of the producers, 69% were obtained from vegetables of the Brassica family. Of the 48 producers, 15 strains gave relatively high yields of mannosylerythritol lipids (MELs), and were identified as Pseudozyma yeasts. These strains produced MELs from olive oil at yields ranging from 8.5 to 24.3?g/L. The best yield coefficient reached 0.49?g/g as to the carbon sources added. Accordingly, MEL producers were isolated at high efficiency from various vegetables and fruits, indicating that biosurfactant producers are widely present in foods. The present results should facilitate their application in the food and related industries. 相似文献
996.
Masaaki Hirose Masatsugu Ueda Hideo Chiba 《Bioscience, biotechnology, and biochemistry》2013,77(12):2433-2439
Liver phosphoglucomutase was found to catalyze also the reaction of Glc-1,6-P2 formation from Glc-1-P and Fru-1,6-Pz or Glc-1-P and glycerate-1,3-P2. The specific activity of Glc-1,6-P2 formation from Glc-1-P and Fru-1,6-P2 was 1/9200 of that of the mutase activity. The activity of Glc-1,6-P2 formation from Glc-1-P and glycerate-1,3-P2 was 1/122,000 of the mutase activity. From the results of the kinetics and the thermal inactivation experiments, the reaction of the mutase and Glc-1,6-P2 synthesis were strongly suggested to occur at the same active site of liver phosphoglucomutase.Liver phosphoglucomutase exhibited the Glc-1,6-P2 phosphatase activity only in the presence of xylose 1-phosphate. The specific activity of phosphatase was only 1/154,000 of that of the mutase activity. 相似文献
997.
Makoto Kandatsu Masaaki Horiguchi Masato Tamari 《Bioscience, biotechnology, and biochemistry》2013,77(8):779-780
Four alcohols, 1-penten-3-ol, n-amylalcohol, trans-2-hexenol and one of the linalool oxides, were newly identified as the components of carbonyl-free neutral fraction of the essential oil of black tea.On the gas chromatogram of carbonyl fraction three unknown peaks were identified with those of n-valeraldehyde, n-heptanal and trans-2-octenal.From these results almost all main components of carbonyl and carbonyl free fractions were clarified.Flavor change during the manufacture of black tea was investigated by gas chromatography. During withering, hexylalcohol, nerol, trans-2-hexenoic acid, trans-2-heхenol, linalool oxide (cis, furanoid), n-valeraldehyde, capronaldehyde, n-heptanal, trans-2-hexenal, trans-2-octenal, benzaldehyde, phenylacetaldehyde, n-butyric, isovaleric, n-caproic, cis-3-hexenoic and salicylic acids and o-cresol were increased, especially the former three greatly increased, while cis-2-pentenol, linalool, geraniol, benzylalcohol, phenylethanol and acetic acid diminished markedly. In the process of fermentation almost all constituents increased, especially, 1-penten-3-ol, cis-2-pentenol, benzylalcohol, trans-2-hexenal, benzaldehyde, n-caproic, cis-3-hexenoic and salicylic acids were remarkable.On firing, most alcohols, carbonyl and phenolic compounds decreased remarkably whereas acetic, propionic and isobutyric acids greatly increased. 相似文献
998.
Masaaki Yoshikawa Makoto Tamaki Etsuro Sugimoto Hideo Chiba 《Bioscience, biotechnology, and biochemistry》2013,77(10):2051-2052
The pyrolyzate of the nondialyzable melanoidin prepared from glucose-ammonia reaction system (kept in pH 5.3~6.0 during the reaction) was fractionated to volatile fraction and nonvolatile fraction. Among the volatile components, two pyridines and four alkylpyrazines were identified. On the other hand, one imidazole compound and two β-hydroxypyridines isolated from the nonvolatile fraction were identified as 4(5)-methylimidazole, 3-hydroxypyridine and 2-methyl-5-hydroxypyridine, respectively. It is inferred that these compounds are not produced by the fission of the main skeleton in the melanoidin molecule, but formed by pyrolysis of the heterocyclic compounds present as a small moiety in the melanoidin. 相似文献
999.
Seizen Toyama Koshin Miyasato Masaaki Yasuda Kenji Soda 《Bioscience, biotechnology, and biochemistry》2013,77(12):2939-2941
Natural ( + )-(1R,2S,3S)-methyl cucurbate (1b) and the ( – )-δ-lactone of 3-epi-cucurbic acid (16) were synthesized from (+)-(1R,6S,7R)-bicyclo [4.3.0] non-3-en-7-ol (5). Asymmetric hydrolysis of the acetate (8) of ( ± )-5 with pancreatin gave optically pure the ( + )-(7R)-alcohol (5) and (–)-(7S)-acetate (8). An ozonolysis product of ( + )-5 was transformed to ( – )-16 and ( + )-(3S)-1b with inversion of the (7R)-hydroxyl group. Similarly, unnatural (–)-1b and (+)-16 were prepared from optically pure ( — )-5. The growth inhibitory activities of these synthesized chiral compounds toward lettuce seedlings were examined. 相似文献
1000.