全文获取类型
收费全文 | 1402篇 |
免费 | 46篇 |
国内免费 | 3篇 |
专业分类
化学 | 1050篇 |
晶体学 | 24篇 |
力学 | 3篇 |
数学 | 28篇 |
物理学 | 346篇 |
出版年
2021年 | 10篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 27篇 |
2015年 | 20篇 |
2014年 | 31篇 |
2013年 | 71篇 |
2012年 | 41篇 |
2011年 | 48篇 |
2010年 | 26篇 |
2009年 | 44篇 |
2008年 | 58篇 |
2007年 | 73篇 |
2006年 | 67篇 |
2005年 | 82篇 |
2004年 | 67篇 |
2003年 | 55篇 |
2002年 | 53篇 |
2001年 | 45篇 |
2000年 | 46篇 |
1999年 | 20篇 |
1998年 | 20篇 |
1997年 | 20篇 |
1996年 | 23篇 |
1995年 | 12篇 |
1994年 | 22篇 |
1993年 | 21篇 |
1992年 | 29篇 |
1991年 | 15篇 |
1990年 | 18篇 |
1989年 | 13篇 |
1988年 | 17篇 |
1987年 | 22篇 |
1986年 | 23篇 |
1985年 | 31篇 |
1984年 | 21篇 |
1983年 | 10篇 |
1982年 | 25篇 |
1981年 | 25篇 |
1980年 | 16篇 |
1979年 | 12篇 |
1978年 | 18篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 16篇 |
1974年 | 17篇 |
1973年 | 12篇 |
1972年 | 6篇 |
排序方式: 共有1451条查询结果,搜索用时 15 毫秒
1.
Atsuhiro Fujimori Mikako Ishitsuka Hiroo Nakahara Eisuke Ito Masahiko Hara Kaname Kanai Hisao Ishii Yukio Ouchi Kazuhiko Seki 《Journal of Polymer Science.Polymer Physics》2004,42(12):2329-2336
Photopolymerization of cadmium 10,12-pentacosadiynoate (CdDA) in Langmuir–Blodgett (LB) films, with the molecular packing well arranged by moderate preannealing, was investigated with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Greenish films of polydiacetylene with an absorption wavelength of 705 nm were obtained through the photopolymerization of preannealed monomer LB films, and this resulted in an extended π-conjugate system based on the well-ordered monomer in a two-dimensional arrangement. The electronic structures of the polydiacetylenes were found to be correlated to the variation of the molecular arrangements in the films from the changes in the NEXAFS spectra through photopolymerization in the LB films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2329–2336, 2004 相似文献
2.
Sayaka Wada Kazuhiko Fujiwara Hideaki Monjushiro Hitoshi Watarai 《Analytical sciences》2004,20(11):1489-1491
The direct measurement of the circular dichroism (CD) spectra of liquid/liquid interface has been achieved for the first time by the centrifugal liquid membrane (CLM) method combined with a conventional CD spectropolarimetry. In the sample chamber of the CD spectropolarimeter, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at ca. 7000 rpm to generate a two-phase liquid membrane with a high specific interfacial area. The CD spectra of the J-aggregate of protonated 5,10,15,20-tetraphenylporphyrin formed at the toluene/sulfuric acid interface in the rotating cell have been measured. The results demonstrated the novelty and advantages of this method. 相似文献
3.
H. Sunaoshi Y. Fukashiro M. Furukawa M. Yamauchi S. Hayashibe T. Shinozuka M. Fujioka I. Satoh M. Wada S. Matsuki 《Hyperfine Interactions》1993,78(1-4):241-245
The ground state hyperfine splitting of87Sr+ was measured with a precision of 1×10–8. The experiments were performed with an RF ion trap connected to an ISOL (isotope separator on-line), where all the possible transitions between Zeeman sublevels were observed by a laser-microwave double resonance method. The magnetic dipole hyperfine constant was determined to beA=–1 000 473.673 (11) kHz. 相似文献
4.
A binary alloy Schottky barrier diode on zinc oxide (ZnO) was developed using the combinatorial ion beam-assisted deposition system. The compositional fraction of the binary alloy was continuously varied using the composition-spread technique, to control the Schottky barrier height. After metal deposition, patterned Schottky diodes were fabricated on a ZnO single-crystal substrate. Pt-Ru alloy was selected from the work function viewpoint. Our experiments showed that the compositional fraction of the Schottky binary alloys changed continuously as designed and the Schottky barrier heights measured by current-voltage (I-V) measurements increased with increasing Pt content. Maximum barrier height difference for ZnO was 137 meV. Using ion beam deposition in parallel with the combinatorial system showed that the Schottky barrier heights for ZnO can be controlled by binary metal alloying. 相似文献
5.
Initial reactions of the metabolic processes in bacterial cells have been investigated by measuring heat generation of under nongrowing conditions with a titrimetric calorimeter. Three exothermic reactions with different rates of heat generation have been observed calorimetrically under aerobic condition when glucose solution was added to the cell suspension of nongrowing medium. It was estimated that the first exothermic peak obtained after adding glucose was due to uptaking of substrate molecules and following two peaks reflected to the reaction of phosphofructokinase and that of glyceraldehyde-3-phosphate dehydrogenase respectively. To clarify the process of glycolysis, measurements of heat evolution due to metabolisms of various sugars except glucose have also examined and compared with that of glucose. 相似文献
6.
7.
8.
The first total synthesis of (+)?3-deoxyaphidicolin, a selective inhibitor of eukaryotic DNA polymerase α, has been completed efficiently and stereoselectively starting from 1-abietic acid. 相似文献
9.
Ray K Nakahara H Sakamoto A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(1-2):103-107
The fluorescence lifetimes decays and picosecond time-resolved fluorescence spectra were measured to investigate the dynamics of the excited state of sulforhodamine B (SRB) molecules adsorbed in the mono- and multilayered Langmuir-Blodgett (LB) films of octadecylamine. Steady-state and time-resolved fluorescence spectroscopy reveals that the fluorescence lifetimes and contents of the monomer and dimers in the molecular organizates depend upon the concentration of the dye in the solution and the adsorption process. SRB dye molecules adsorbed in LB films have been imaged with scanning near-field optical microscopy (SNOM). This information is exploited to map the distribution with molecular spatial resolution. SNOM provide the visual evidence of the monomers and dimers of SRB in cationic LB films. 相似文献
10.