全文获取类型
收费全文 | 232篇 |
免费 | 0篇 |
专业分类
化学 | 184篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 10篇 |
物理学 | 33篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 13篇 |
2011年 | 12篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 12篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 13篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1971年 | 1篇 |
排序方式: 共有232条查询结果,搜索用时 15 毫秒
31.
The moment analyses were performed on the far-infrared absorption bands of CH3CN, CHCl3, CH2Cl2, and their deuterated compounds dissolved in nonpolar solvents. The values of torque acting on the solute molecules were estimated from the fourth moments. The band profiles were simulated by means of the continued-fraction representation of the time correlation function by Mori, using the moment values obtained. The third order long-time approximation of the correlation function yields essentially good simulations. The effective rotation angles of molecules between collisions were estimated from the first positive-to-negative turning points of the memory functions. The solvent effects on the torque and the rotation angle were consistent with each other. 相似文献
32.
33.
34.
Ken-ichi Kanno Shun-ichi Naoe Seiji Mukai Yoshio Nakai Takeshi Miyanaga 《Solid State Communications》1973,13(9):1325-1328
The absorption spectra of CdCl2 and CdBr2 single crystals doped with cuprous or cupric halides were measured. Optical bleaching of the absorption bands due to Cu+ gives rise to new absorption bands which suggest the conversion of Cu+→Cu2+. This was confirmed also by detecting the growth in ESR signals characteristic of Cu2+ centers. 相似文献
35.
36.
By ferricyanide oxidation of 2-(4-methoxyphenyl)phenanthro[9,10-d]imidazole, three new photochromic compounds were obtained. These were 4-ethoxy-4H-, 4-methoxy-4H- and 2-methoxy-2H-phenanthro[9,10-d]imidazoles. These compounds gave the 2-(4-methoxyphenyl)-phenanthro[9,10-d]imidazolyl radical and acetaldehyde or formaldehyde by light irradiation. The imidazolyl radical dimerized gradually in the dark and the dimer dissociated to the imidazolyl radical on heating. 相似文献
37.
Matsuura S Yokoyama T Ishii R Itoh T Tomon E Hamakawa S Tsunoda T Mizukami F Nanbu H Hanaoka TA 《Chemical communications (Cambridge, England)》2012,48(56):7058-7060
A flow-type microreactor containing glutaminase-mesoporous silica composites with 10.6 nm pore diameter (TMPS10.6) was developed for the continuous synthesis of theanine, a unique amino acid. High enzymatic activity was exhibited by the local control of the reaction temperature. 相似文献
38.
Sakae Uemura Haruo Miyoshi Masaya Okano Isao Morishima Toshiro Inubushi 《Journal of organometallic chemistry》1979,165(1):9-19
Treatment of norbornene, norbornadiene, benzonorbornadiene, and chloro- and methoxy-benzonorbornadiene with thallium(III) acetate in methanol affords only the corresponding cis-exo-acetoxythallation adducts in a sharp contrast to oxymercuration of such strained olefins where methoxymercuration prevails. In the cases of substituted benzonorbornadienes the products are obtained as the regioisomeric mixtures, the isomer ratio being determined by 13C NMR. In the cases of 5-norbornene-2,3-dicarboxylic anhydride, 5-norbornene-2-methyl-2,3-dicarboxylic anhydride, and 5-norbornen-2-endo-carboxylic acid, lactonization occurs to give a trans-oxythallation adduct having a lactone ring, no introduction of either methoxy or acetoxy groups being observed. 1H and/or 13C NMR data for several new oxythallation adducts are provided. The alkaline sodium borohydride reduction of adducts in methanol affords mainly the parent olefin together with 10–16% yields of the corresponding exo-alcohol. 相似文献
39.
40.
Yoshihiro Itoh Yotaro Morishima Shun-ichi Nozakura 《Photochemistry and photobiology》1984,39(5):603-608
Abstract— Photosensitized reduction of zwitterionic viologen (SPV) and methyl viologen (MV2+ ) was investigated using an amphiliphilic copolymer having phenanthryl and sulfonate groups (APh) as photosensitizer in aqueous solutions. In the presence of triethanolamine the accumulation of SPV * (photoproduct) was found to be faster than that of MV+ . This attributed to the electrostatic repulsion between SPV. and anionic segments of APh. Such difference between SPV and MV2+ was minimized in the case of the related monomer model. Retardation of the back reaction for the APh-SPV system was also demonstrated by laser photolysis, k b = 8.7 × 107 M -1 s-1 for the polymer system as compared to k b = 2.8 × 109 M -1 s-1 for the monomer model system. Strong salt-effects on the yield of the photoreduction and the rate of back reaction confirm the strong electrostatic interaction between the photoproducts and polyanions. This remarkable electrostatic effect of the polyanions was simulated by electrochemical redox reactions by using a graphite electrode coated with APh. 相似文献