全文获取类型
收费全文 | 376篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
化学 | 271篇 |
晶体学 | 1篇 |
力学 | 9篇 |
数学 | 20篇 |
物理学 | 89篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 13篇 |
2013年 | 17篇 |
2012年 | 16篇 |
2011年 | 18篇 |
2010年 | 11篇 |
2009年 | 26篇 |
2008年 | 23篇 |
2007年 | 16篇 |
2006年 | 19篇 |
2005年 | 22篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 11篇 |
2001年 | 6篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1967年 | 2篇 |
1964年 | 2篇 |
排序方式: 共有390条查询结果,搜索用时 31 毫秒
111.
Norihiro Sei Hiroshi Ogawa Kawakatsu Yamada Masaki Koike Hideaki Ohgaki 《Journal of synchrotron radiation》2014,21(4):654-661
Higher harmonics of spontaneous emission from an optical klystron have been observed. The modulation factor of the spontaneous emission spectrum for the higher harmonics can be described by considering the observation system. When the dispersive gap of the optical klystron was fixed, the microstructure interval of the spontaneous emission spectrum at a certain resonant wavelength became narrower as the order of the higher harmonic became larger. Some unique characteristics of the higher harmonics have been clarified, and these studies are likely to contribute to the development of free‐electron lasers using higher harmonics of an optical klystron in the shorter‐wavelengths region. 相似文献
112.
Norifumi Kishi Dr. Zhiou Li Dr. Yoshihisa Sei Prof. Dr. Munetaka Akita Dr. Kenji Yoza Prof. Dr. Jay S. Siegel Dr. Michito Yoshizawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(20):6313-6320
This article reports that an M2L4 molecular capsule is capable of encapsulating various neutral molecules in quantitative yields. The capsule was obtained as a single product by mixing a small number of components; two PdII ions and four bent bispyridine ligands containing two anthracene panels. Detailed studies of the host capability of the PdII‐linked capsule revealed that spherical (e.g., paracyclophane, adamantanes, and fullerene C60), planar (e.g., pyrenes and triphenylene), and bowl‐shaped molecules (e.g., corannulene) were encapsulated in the large spherical cavity, giving rise to 1:1 and 1:2 host–guest complexes, respectively. The volume of the encapsulated guest molecules ranged from 190 to 490 Å3. Within the capsule, the planar guests adopt a stacked‐dimer structure and the bowl‐shaped guests formed an unprecedented concave‐to‐concave capsular structure, which are fully shielded by the anthracene shell. Competitive binding experiments of the capsule with a set of the planar guests established a preferential binding series for pyrenes≈phenanthrene>triphenylene. Furthermore, the capsule showed the selective formation of an unusual ternary complex in the case of triphenylene and corannulene. 相似文献
113.
Dr. Hirokazu Komatsu Kazuki Yoshihara Dr. Hisatsugu Yamada Dr. Yu Kimura Dr. Aoi Son Prof. Dr. Sei‐ichi Nishimoto Dr. Kazuhito Tanabe 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(6):1971-1977
The phosphorescence emission of ruthenium complexes was applied to the optical imaging of physiological hypoxia. We prepared three complexes with hydrophobic substituents on the phenanthroline ligand and characterized their emission, which was quenched by molecular oxygen. Among the complexes synthesized in this study, a pyrene chromophore‐linked ruthenium complex, Ru‐Py, exhibited optimal properties for the imaging of hypoxia; the prolonged lifetime of the triplet excited state of the ruthenium chromophore, which was induced by efficient energy distribution and transfer from the pyrene unit, provided the highest sensitivity towards molecular oxygen. The introduction of hydrophobic pyrene increased the lipophilicity of the complex, leading to enhanced cellular uptake. Consequently, the bright phosphorescence of Ru‐Py was seen in the cytoplasm of viable hypoxic cells, whereas the signal from aerobic cells was markedly weaker. Thus, we could clearly discriminate between hypoxic and aerobic cells by monitoring the phosphorescence emission. Furthermore, Ru‐Py was applied to optical imaging in live mice. An intramuscular injection of Ru‐Py successfully visualized ischemia‐based hypoxia, which was constructed by leg banding. 相似文献
114.
Prof. Dr. Hak Joong Kim Dr. Sei‐hyun Choi Byung‐sun Jeon Dr. Namho Kim Prof. Dr. Rongson Pongdee Dr. Qingquan Wu Prof. Dr. Hung‐wen Liu 《Angewandte Chemie (International ed. in English)》2014,53(49):13553-13557
Following the biosynthesis of polyketide backbones by polyketide synthases (PKSs), post‐PKS modifications result in a significantly elevated level of structural complexity that renders the chemical synthesis of these natural products challenging. We report herein a total synthesis of the widely used polyketide insecticide spinosyn A by exploiting the prowess of both chemical and enzymatic methods. As more polyketide biosynthetic pathways are characterized, this chemoenzymatic approach is expected to become readily adaptable to streamlining the synthesis of other complex polyketides with more elaborate post‐PKS modifications. 相似文献
115.
116.
Motoshi Nakamura Hiroshi Saitoh Yoshio Maejima Sei -ichi Yamagiwa Shoji Kaneko 《Fresenius' Journal of Analytical Chemistry》1989,335(6):573-575
Summary Five alumina-containing gels were investigated on the adsorption characteristics for four types of organic dyes (acidic, basic, reactive, and direct dyes). Alumina-magnesias exhibited the properties as strong solid bases and adsorbed effectively three dyes except for the acidic dye. While, alumina-silicas, strong solid acids, showed the high ability only for the acidic dye.
Part I: see [5] 相似文献
Adsorptionscharakteristica organischer Farbstoffe in wäßrigen Lösungen auf gemischten OxidgelenII. Aluminiumoxid-haltige gemischte Oxidgele
Part I: see [5] 相似文献
117.
118.
119.
Yoshihisa Sei Sakurako Shimotakahara Juri Ishii Heisaburo Shindo Hiroko Seki Kentaro Yamaguchi Mitsuru Tashiro 《Analytical sciences》2005,21(4):449-451
The characterization of water molecules bound to ribonuclease T1 (RNase T1) was carried out using cold-spray ionization mass spectrometry (CSI-MS). CSI-MS is a variant of electrospray ionization mass spectrometry (ESI-MS) operating at low temperature, and is particularly suitable for investigating the weaker molecular associations, since the temperature at the spray interface is much lower than that in the conventional ESI-MS. In this approach, ion peaks due to the addition of nine water molecules were identified at a spray temperature of 48 degrees C. This result showed good agreement with that inferred by the combinational analysis of NMR and X-ray crystallography, indicating that CSI-MS is capable of rapidly providing reliable information to characterize the number of water molecules bound to a macromolecule. 相似文献
120.
Yoshimoto Onishi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1991,42(3):348-361
The thermal-creep flow of a binary gas mixture over a plane wall is investigated analytically on the basis of the linearized Boltzmann equation of BGK type under the boundary condition of Maxwell's type or diffuse-specular reflection type. By an accurate analysis of the Knudsen layer formed near the wall, the Knudsen-layer structure of the velocity field has been clarified and, hence, the velocity distribution over the whole flow region is given explicitly together with the macroscopic slip coefficient. For future comparison with experimental data which may become available, the values of the slip coefficient of thermal-creep flow for several pairs of gases, Ne-Ar, He-Ne, He-Ar, N2-Ar and N2-O2 are also given and listed in Table together with the values calculated based on the result given by other authors. 相似文献