全文获取类型
收费全文 | 2052篇 |
免费 | 118篇 |
出版年
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 13篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 35篇 |
2015年 | 51篇 |
2014年 | 56篇 |
2013年 | 108篇 |
2012年 | 109篇 |
2011年 | 114篇 |
2010年 | 69篇 |
2009年 | 71篇 |
2008年 | 98篇 |
2007年 | 112篇 |
2006年 | 98篇 |
2005年 | 104篇 |
2004年 | 103篇 |
2003年 | 92篇 |
2002年 | 96篇 |
2001年 | 68篇 |
2000年 | 69篇 |
1999年 | 57篇 |
1998年 | 24篇 |
1997年 | 28篇 |
1996年 | 24篇 |
1995年 | 29篇 |
1994年 | 23篇 |
1993年 | 19篇 |
1992年 | 37篇 |
1991年 | 46篇 |
1990年 | 34篇 |
1989年 | 34篇 |
1988年 | 31篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 23篇 |
1984年 | 26篇 |
1983年 | 16篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1975年 | 11篇 |
1974年 | 8篇 |
1972年 | 7篇 |
1969年 | 8篇 |
排序方式: 共有2170条查询结果,搜索用时 15 毫秒
101.
Keun-Hyung Park Takao Yokota Akira Sakurai Nobutaka Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(11):3081-3086
The rice lamina inclination test indicated the presence of brassinosteroid-like active substances in immature Vicia faba seeds. Two of these were identified as castasterone and brassinolide by GC/MS and GC/SIM, respectively. Another active principle was identified as methyl 4- chloroindole-3-acetate by GC/MS and HPLC. 相似文献
102.
Li-NH3 reduction of helminthosporic acid gave dihydrohelminthosporic acid (III) and allodihydrohelminthosporic acid (IV). III and IV are the epimers with respect to the carboxyl and III is labil form. The stereochemistry of III and IV is elucidated from the chemical and spectroscopic evidences. III showed a marked plant growth promoting activity but IV did not. 相似文献
103.
Masao Fujimaki Soichi Arai Norimasa Kirigaya Yosito Sakurai 《Bioscience, biotechnology, and biochemistry》2013,77(9):855-863
Aliphatic carbonyl compounds in soybean were studied. Volatile carbonyl compounds in defatted soybean flour were identified as methanal, ethanal, n-hexanal, 2-propanone, 2- pentanone, 2-heptanone, 2-heptenal, and 2,4-decadienal, while those in raw soybean as ethanal, n-hexanal, and 2-propanone. Four kinds of non-volatile carbonyl compounds were found in defatted soybean, two of which seemed to be carbonyl ester and carbonylic acid. It is probable that the compounds in defatted soybean are mostly the secondary products derived from autoxidation of the residual fatty acids and esters in the defatting process and/or during the storage thereafter. n-Hexanal in raw soybean amounts to approximately 10 p.p.m., which is, owing to its extremely low flavoring threshold, likely to be one of the main components of the green bean flavor. 相似文献
104.
Soichi Arai Hideki Suzuki Masao Fujimaki Yosito Sakurai 《Bioscience, biotechnology, and biochemistry》2013,77(4):364-369
Ethanol (1:1) extract of defatted soybean flour was fractionated systematically and the resulting phonolic acid fraction was investigated. This fraction had strong phenol-like flavor and contained at least seven phenolic acids including syringic, vanillic, ferulic, gentisic, salicylic, p-coumaric, and p-hydroxybenzoic acids. The main component among these was syringic acid, which was isolated as 3,5-dinitrobenzoate.In addition, two isomers of chlorogenic acids, presumably isochlorogenic and chlorogenic acids approximately in a ratio of 1 : 10, were found in this extract. These substances have sour, bitter and astringent flavors. 相似文献
105.
Tadao Kurata Hideo Wakabayashi Yosito Sakurai 《Bioscience, biotechnology, and biochemistry》2013,77(1):101-105
In the presence of oxygen, L-ascorbic acid sol ution (0.05 M) browned more intense1 y than dehydro-L-ascorbic acid solution (0.05 M) during storage for longer period.The mixed solution of L-ascorbic acid (ASA) and dehydro-L-ascorbic acid (DHA) with the ratio of 1:1 or 1:3 in concentration gave more intense browning than DHA solution during storage at 38°C for about 3 weeks. Essentially the same type of browning was observed in case of the mixture of ASA and DHA with D-glucose. Browning of partially oxidized ASA solution also showed substantially the same results as those mentioned above. 相似文献
106.
Koshi Arai Tetsu Ando Akira Sakurai Hideo Yamada Tatsuo Koshihara Nobutaka Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(9):2395-2397
Gibberellins A4 and A36 were identified from flowering and vegetative apices of ten month-old sugarcane (Saccharum spp. hybrids) plants. The identifications were based on retention times, relative to authentic standards, on sequential silica gel partition column chromatography→bioassay→C18 reverse phase high performance liquid chromatography→bioassay→ capillary gas chromatography (GC), and on GC-selected ion monitoring (SIM), the relative intensities of six characteristic ions being monitored in comparison with authentic standards. 相似文献
107.
Koji Ikura Hiroshi Sakurai Katsuzumi Okumura Ryuzo Sasaki Hideo Chiba 《Bioscience, biotechnology, and biochemistry》2013,77(12):3527-3531
Guinea pig liver transglutaminase was purified in a yield of more than 80% by a one-step purification procedure using an immunoadsorbent column of monoclonal antibodies. Active enzyme could be recovered by alkaline buffer desorption and quick neutralization. The purified enzyme was more than 98% homogeneous on Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, and had the same enzymological and immunological properties as those of the enzyme purified by conventional procedures. 相似文献
108.
Toshiya Kamikado Ching-Fun Chang Shigeo Murakoshi Akira Sakurai Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(4):833-836
Two lignans were isolated from leaves of Magnolia kobus DC. as growth inhibitors on silkworm larvae and structurally elucidated as sesamin (I) and kobusin (II) which has been hitherto unknown. 相似文献
109.
110.
Ryotaro Myokei Akira Sakurai Ching-Fun Chang Yoshinori Kodaira Nobutaka Takahashi Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(10):1491-1500
A new insecticidal substance named aspochracin was isolated from the culture filtrate of Aspergillus ochraceus, a pathogenic fungus causing muscardine on insects. The compound was found to be a novel cyclotripeptide, composed of N-methyl-l-alanine, N-methyl-l-valine and l-ornithine, containing an octatrienoic acid side chain. Isolation procedure, structural elucidation and biological activities are described in detail.Hexahydroaspochracin (II) derived on hydrogenation of aspochracin (I), an insecticidal metabolite of Aspergillus ochraceus, was synthesized by cyclization of N-methyl-l-valyl-N- methyl-l-alanyl-α-caprylyl-l-ornithine (XIV). In addition to II, isohexahydroaspochracin (XV) was isolated from the reaction mixture. 相似文献