全文获取类型
收费全文 | 317篇 |
免费 | 11篇 |
专业分类
化学 | 259篇 |
力学 | 1篇 |
数学 | 19篇 |
物理学 | 49篇 |
出版年
2022年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2017年 | 3篇 |
2016年 | 12篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 7篇 |
2012年 | 20篇 |
2011年 | 23篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 20篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 19篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 9篇 |
1991年 | 2篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1963年 | 1篇 |
1959年 | 2篇 |
1903年 | 1篇 |
1896年 | 1篇 |
1895年 | 1篇 |
排序方式: 共有328条查询结果,搜索用时 15 毫秒
81.
Electron spin resonance studies showed that addition of rat liver microsomes to the reaction system of alloxan with reduced nicotinamide adenine dinucleotide phosphate (NADPH) resulted in a marked increase in the generation of alloxan radicals (AH.), whereas heat-denatured microsomes were without such effect. Oxidation of NADPH by alloxan was also stimulated by microsomes. The microsomes from rats treated with phenobarbital, an inducer of cytochrome P-450 reductase, greatly stimulated both the AH.generation and the NADPH oxidation. However, the microsomes from rats treated with 3-methylcholanthrene, an inducer of DT-diaphorase, did not have stimulative effect greater than the control microsomes. These results suggest the possibility that NADPH-linked AH.generations in microsomal membranes is catalyzed by NADPH-cytochrome P-450 reductase. 相似文献
82.
Kanae Hayashi Michinori Tachibana Seizo Okamura 《Journal of polymer science. Part A, Polymer chemistry》1980,18(12):3381-3391
Radiation-induced polymerization of isoprene in bulk state was studied at 25°C in a wide dose rate range. Variations of the rate of polymerization and molecular weight of the products were essentially the same as those observed in the monomers which were capable of both radical and cationic polymerizations. At low dose rate, 7.0-230 rad/sec, radical polymerization took place. At high dose rate, 8.8 × 103-2.2 × 105 rad/sec, radical and cationic polymerizations took place concurrently. The average molecular weight of the high-dose-rate product was about 850, independent of dose rate. The microstructure of the products at high dose rate consisted mainly of trans- 1,4 units with only about 7% of cis- 1,4 and 10% of 3,4-vinyl units. The residual unsaturation in the high-dose-rate products was 90%. Decreases in cis units and residual unsaturation at high dose rate were accounted for by the change in predominant mechanism of polymerization with dose rate. 相似文献
83.
N. Metoki Y. Koike Y. Haga T. Honma M. Sato Y.
nuki N. Kimura K. Maesawa H. Amitsuka M. Yokoyama K. Kuwahara Y. Miyako 《Physica B: Condensed Matter》2000,280(1-4):362-367
We review recent neutron scattering studies on uranium-based heavy-fermion superconductors. The coupling between magnetic and superconducting order parameters was observed in UPt3, UPd2Al3, URu2Si2, and UNi2Al3. In UPd2Al3, the superconducting gap appears in the spin excitation spectra. These results are indicative of the strong interplay between magnetism and superconductivity. We also report the unusual behaviors of the weak antiferromagnetic ordering, the long-range magnetic correlation in UPt3 at ultra-low temperatures, and the pressure-induced magnetic transition from the weak (0.02μB/U) to a high moment state (0.4μB/U) at 1.5 GPa in URu2Si2. 相似文献
84.
85.
86.
87.
The atomic vibrations in crystalline, amorphous and liquid iron are discussed based on the realistic models simulated in a computer. The frequency distribution functions of amorphous and liquid iron are of double peak and a single peak, respectively. 相似文献
88.
Michinori ki 《Angewandte Chemie (International ed. in English)》1976,15(2):87-93
Rotation about CC single bonds in suitably substituted compounds gives rise to rotational isomers (also called rotamers) which can be isolated if the barrier to rotation is high enough. The present article considers derivatives of triptycene and fluorene whose barriers to rotation are of the order of 30 kcal/mol. 相似文献
89.
90.
P. Reinouts van Haga 《Mikrochimica acta》1976,66(5-6):543-547
Summary Use is made of the high stability of the photometric system of the Enzyrator. This stability, together with the possibility of multiplying the read-out by a factor of 10, make it possible to decrease the sample size by the same factor.
Zusammenfassung Die besondere Stabilität der photometrischen Anzeige des Enzyrators sowie die Möglichkeit, die Anzeige zu verzehnfachen, bieten die Voraussetzung, die Probengröße um denselben Faktor zu verkleinern.相似文献