全文获取类型
收费全文 | 1092篇 |
免费 | 57篇 |
国内免费 | 5篇 |
专业分类
化学 | 929篇 |
晶体学 | 12篇 |
力学 | 11篇 |
数学 | 40篇 |
物理学 | 162篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 6篇 |
2020年 | 15篇 |
2019年 | 19篇 |
2018年 | 8篇 |
2017年 | 13篇 |
2016年 | 21篇 |
2015年 | 32篇 |
2014年 | 32篇 |
2013年 | 48篇 |
2012年 | 58篇 |
2011年 | 75篇 |
2010年 | 34篇 |
2009年 | 35篇 |
2008年 | 73篇 |
2007年 | 72篇 |
2006年 | 74篇 |
2005年 | 50篇 |
2004年 | 48篇 |
2003年 | 37篇 |
2002年 | 33篇 |
2001年 | 12篇 |
2000年 | 20篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1997年 | 10篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 27篇 |
1984年 | 16篇 |
1983年 | 17篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1976年 | 13篇 |
1975年 | 10篇 |
1974年 | 8篇 |
排序方式: 共有1154条查询结果,搜索用时 31 毫秒
121.
122.
123.
Quark mixings and theor momentum dependences are discussed in a subquark model in which the weak current is made of the iso-doublet spinor subquarks. The Cabibbo angle is predicted to become larger as momentum transfer between quarks grows up. 相似文献
124.
Keiichi Ohno Hiroatsu Matsuura Don McNaughton Harold W. Kroto 《Journal of Molecular Spectroscopy》1985,111(2):415-424
The infrared spectra of 1-phosphapropyne, CH3CP, and its perdeuteride, CD3CP, have been measured in the gaseous and solid states. The QK branches of perpendicular bands have been analyzed in terms of the usual quadratic expression in K. Fermi resonances were identified for the ν1, ν2 + ν3, 2ν3, 2ν60; and ν5, 2ν3 + ν8 band systems of CH3CP and the ν1, 2ν3, 2ν60; ν6, ν7 + ν8; and ν7, 3ν81 band systems of CD3CP. The xy Coriolis interaction was also identified between the ν3 and ν6 bands of the two species. All the fundamentals were assigned and the normal coordinate treatment was carried out along with the Coriolis constants, ζz. 相似文献
125.
Cationic (carbene) organopalladium(II) complexes coordinated with cyclic diolefin or organic nitrile
The chloro-bridged (carbene)organopalladium(II) complex, di-μ-chlorobis(1,3-diphenyl-2-imidazolidinylidenato-2-C,2′-C)dipalladium(II) underwent chlorine abstraction with silver perchlorate in the presence of a cyclic diolefin or an organic nitrile, to give new cationic (carbene)organopalladium(II) complexes coordinated with the respective substrates. These new complexes were characterized by means of elemental analysis, molar conductivities, and IR and 1H NMR spectroscopy. 相似文献
126.
Hisakazu Kotani Masayoshi Yamada Keiichi Yamamoto Kenji Abe 《Solid State Communications》1982,41(6):461-463
Time-resolved optical transmission of annealing dye laser pulse (wavelength : 590 nm and pulse width : 250 nsec) itself has been measured in thin layers of Si+-implanted amorphized silicon-on-sapphire (SOS) with several energy densities in the range of 0.02 to 2.64 J/cm2. At the energy densities where the amorphized SOS is recrystallized, the transmission exhibits a sudden drop and subsequently remains at a detectable level. This laser-induced absorption is inconsistent with the presence of ordinary molten silicon but suggests an electronic structural-change from amorphous to crystalline state. 相似文献
127.
128.
129.
Kumio Okaichi Nobuyuki Kajitani Katuko Nakajima Keiichi Nozu † Takeo Ohnishi † 《Photochemistry and photobiology》1989,50(1):69-73
Irradiation by health lamp (HL) light (280–320 nm) more efficiently induced cell killing and mutation in a radiation sensitive mutant (TW8) of Dictyostelium discoideum as compared with the parental wild-type strain (NC4). This light as well as a germicidal lamp-light (254 nm) produced pyrimidine dimers. The dimers were removed from DNA molecules by excision repair in NC4, but more slowly in TW8. It is suggested that pyrimidine dimers are the main DNA damage caused by HL light in D. discoideum , and that this results in cell killing and induced mutation. 相似文献
130.
4-Diazomethyl-substituted coumarins, 1-methyl-2(1H)-quinolinones, 1 -thiocoumarin and their tricyclic analogs were found to be easily cyclized into the corresponding pyrazole isomers condensed with heteroaromatics. Thermodependent feature of these conversions and the remarkably accelerating effect of the alkyl substituent peri to the diazomethyl group were realized. Some other diazomethyl compounds connected with 2-pyridinone, 3-pyrazolone, chromone and 1-thiochromone were prepared, and their stability and thermal properties were compared. 相似文献