全文获取类型
收费全文 | 2340篇 |
免费 | 66篇 |
国内免费 | 6篇 |
专业分类
化学 | 1653篇 |
晶体学 | 34篇 |
力学 | 20篇 |
数学 | 53篇 |
物理学 | 652篇 |
出版年
2022年 | 20篇 |
2021年 | 29篇 |
2020年 | 32篇 |
2019年 | 38篇 |
2018年 | 26篇 |
2017年 | 15篇 |
2016年 | 42篇 |
2015年 | 39篇 |
2014年 | 55篇 |
2013年 | 97篇 |
2012年 | 85篇 |
2011年 | 96篇 |
2010年 | 56篇 |
2009年 | 64篇 |
2008年 | 131篇 |
2007年 | 109篇 |
2006年 | 129篇 |
2005年 | 119篇 |
2004年 | 141篇 |
2003年 | 100篇 |
2002年 | 78篇 |
2001年 | 56篇 |
2000年 | 40篇 |
1999年 | 47篇 |
1998年 | 22篇 |
1997年 | 21篇 |
1996年 | 37篇 |
1995年 | 40篇 |
1994年 | 28篇 |
1993年 | 27篇 |
1992年 | 52篇 |
1991年 | 44篇 |
1990年 | 27篇 |
1989年 | 34篇 |
1988年 | 22篇 |
1987年 | 33篇 |
1986年 | 33篇 |
1985年 | 35篇 |
1984年 | 21篇 |
1983年 | 17篇 |
1982年 | 28篇 |
1981年 | 22篇 |
1980年 | 31篇 |
1979年 | 20篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 13篇 |
1975年 | 20篇 |
1974年 | 20篇 |
1973年 | 25篇 |
排序方式: 共有2412条查询结果,搜索用时 0 毫秒
81.
Y Ikeya H Mitsuhashi H Sasaki Y Matsuzaki T Matsuzaki E Hosoya 《Chemical & pharmaceutical bulletin》1990,38(1):136-141
After oral administration of gomisin A (1) to rats, the bile and urine were collected and treated with beta-glucuronidase and arylsulfatase. Seven metabolites, met B (2), met A-III (3), met E (4), met D (5), met F (6), met G (7), and met H (8) were isolated from the bile treated with the enzymes. Eight metabolites 2-8, and met A-II (9) were isolated from the urine treated with the enzymes. A major metabolite 2, and two minor metabolites 3 and 9 were identified as met B, met A-III, and met A-II, respectively, which are oxidative products of 1 formed by rat liver S9 mix. The structures of five new metabolites 4-7, and 8 were determined on the basis of chemical and spectral studies. 相似文献
82.
Yorihiko Sasaki Shigehiro Konaka Takao Iijima Masao Kimura 《International journal of quantum chemistry》1982,21(2):475-485
The total (elastic and inelastic) intensity of electrons scattered by CO2 was measured in the s range of 1 to 12 Å?1 and compared with the theoretical intensity calculated from the Hartree-Fock molecular wave function and those calculated for the independent-atom-model (IAM ) molecule. In the range of s ? 4 Å?1 the electron correlation effect on the total scattered intensity was found to be represented by that for the IAM molecule. 相似文献
83.
When tert-alcohols were treated with (COOH)2 and NaSCN in the presence of iodine, tertiary alkyl isothiocyanates were obtained in good yield, whereas the corresponding thiocyanates were obtained in low yield in the absence of iodine. 相似文献
84.
Kevin E. Bassler Kazuo Sasaki Robert B. Griffiths 《Journal of statistical physics》1991,62(1-2):45-88
Certain features in Frenkel-Kontorova and other models of phases with a one-dimensional modulation can be analyzed by assuming parallel interfaces separating sets of lattice planes belonging to two different phases, and treating the free energy to create interfaces, as well as the interaction of two, three, or more interfaces, as phenomenological parameters. A strategy employed by Fisher and Szpilka for interacting defects can be extended to the case of interfaces, allowing a systematic study of the phase diagram by ignoring all interface interactions, and then successively taking into account pair, triple, and higher-order terms. The possible phase diagrams which can occur near the point where =0 include: various sorts of endpoints analogous to critical endpoints, an accumulation point of first-order transitions and triple points, and a self-similar structure which we call an upsilon point, which turns out to be an accumulation point of an infinite number of segments of first-order transition lines, each of which terminates in two upsilon points. 相似文献
85.
86.
87.
88.
89.
Four new iridoid glycosides, named L-phenylalaninosecologanin (1), 7-O-(4-beta-D-glucopyranosyloxy-3-methoxybenzoyl)secologanolic acid (2), 6'-O-(7alpha-hydroxyswerosyloxy)loganin (3) and (Z)-aldosecologanin (5), were isolated, together with a known one, newly named (E)-aldosecologanin (4), from the stems and leaves of Lonicera japonica. Their structures were established on the basis of chemical and spectral data. 相似文献
90.
Nakamura K Suzuki T Hasegawa M Kato Y Sasaki H Inouye K 《Journal of chromatography. A》2003,1009(1-2):133-139
An affinity sorbent, hydrophilic polymer-based carrier of different pore size (Toyopearl) with immobilized p-aminobenzamidine (ABA), has been prepared. Its basic properties and some applications for protein purification were studied. ABA, which is a synthetic inhibitor for trypsin-like proteases, was covalently immobilized to Toyopearl by reductive amination. The ligand density and binding capacity for porcine trypsin varied depending on the pore size of Toyopearl. The maximum binding capacity of the immobilized p-aminobenzamidine Toyopearl (ABA-Toyopearl) for trypsin was more than 40 mg/ml gel. ABA-Toyopearl thus obtained was very stable below pH 8 and was successfully used for high-performance affinity chromatography of trypsin-like proteases such as trypsin, thrombin, tissue-type plasminogen activator or urokinase in a single step at 25 degrees C. 相似文献