全文获取类型
收费全文 | 949篇 |
免费 | 40篇 |
国内免费 | 4篇 |
专业分类
化学 | 778篇 |
晶体学 | 9篇 |
力学 | 16篇 |
数学 | 35篇 |
物理学 | 155篇 |
出版年
2023年 | 7篇 |
2022年 | 11篇 |
2020年 | 24篇 |
2019年 | 18篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 24篇 |
2014年 | 21篇 |
2013年 | 48篇 |
2012年 | 49篇 |
2011年 | 67篇 |
2010年 | 34篇 |
2009年 | 31篇 |
2008年 | 58篇 |
2007年 | 45篇 |
2006年 | 57篇 |
2005年 | 46篇 |
2004年 | 48篇 |
2003年 | 35篇 |
2002年 | 30篇 |
2001年 | 17篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 17篇 |
1997年 | 11篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 21篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1973年 | 6篇 |
排序方式: 共有993条查询结果,搜索用时 378 毫秒
101.
102.
Masazumi Ishiguro Kensuke Harada Keiichi Tanaka Takehiko Tanaka 《Journal of Molecular Spectroscopy》1996,180(2)
Rotational transitions of fluoroacetylene in the ν1(CH stretch) vibrational state have been observed by the laser–microwave double resonance technique using a color center laser as a radiation source in the 3 μm region. The rotational constant and centrifugal distortion constant in the ν1state were determined to be 9684.310(16) MHz and 2.68(62) kHz, respectively, where the uncertainties given in parentheses correspond to 2.5 standard deviations. 相似文献
103.
The extraction behavior of mono-, poly-, anal bis-(benzothiacrown ether)s is studied for alkali, alkaline-earth, heavy, and transition metal ions in the presence of picrate. These ethers show high selectivity for silver ion. Silver extractions from binary and quaternary mixtures of silver with heavy or transition metal ions were successful, except for mixtures with mercury(II) ion. Silver was extracted from a copper ore with ca. 80% recovery. 相似文献
104.
105.
M Shibasaki A Takahashi T Aoki H Sato S Yamada M Kudo K Kogi S Narita 《Chemical & pharmaceutical bulletin》1992,40(1):279-281
A synthesis of a novel and chemically stable homoisocarbacyclin analog, TY-11223 (3), has been accomplished. The analog (3), given intravenously or orally, showed potent and long-lasting activities in inhibiting platelet aggregation and, in addition, a good selectivity in biological activities. 相似文献
106.
107.
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
108.
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
109.
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
110.
Tadashi Narita Hiroshi Hamana Fumiaki Sekiya Yasuyuki Nojima 《Journal of polymer science. Part A, Polymer chemistry》2007,45(5):908-910
To report a new polymerization reaction phenomenon, this article examines the polymerization of butyl vinyl ether and N‐vinylcarbazole in the presence of 2‐benzoxypentafluoropropene [CF2?C(CF3)OCOC6H5 or BPFP]. The homopolymer of butyl vinyl ether was produced in the presence of a catalytic amount of BPFP in high yields. N‐Vinylcarbazole, which is a monomer well‐known for producing its homopolymer under cationic polymerization conditions, also yielded its homopolymer in the presence of BPFP. It was concluded that some cationic species would be yielded by the addition of BPFP. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 908–910, 2007. 相似文献