全文获取类型
收费全文 | 592篇 |
免费 | 19篇 |
国内免费 | 9篇 |
专业分类
化学 | 382篇 |
晶体学 | 7篇 |
力学 | 6篇 |
数学 | 73篇 |
物理学 | 152篇 |
出版年
2023年 | 3篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 15篇 |
2018年 | 7篇 |
2016年 | 18篇 |
2015年 | 6篇 |
2014年 | 10篇 |
2013年 | 27篇 |
2012年 | 28篇 |
2011年 | 32篇 |
2010年 | 26篇 |
2009年 | 25篇 |
2008年 | 21篇 |
2007年 | 39篇 |
2006年 | 34篇 |
2005年 | 33篇 |
2004年 | 22篇 |
2003年 | 27篇 |
2002年 | 24篇 |
2001年 | 18篇 |
2000年 | 23篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1976年 | 11篇 |
1975年 | 7篇 |
1973年 | 4篇 |
1970年 | 5篇 |
1969年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有620条查询结果,搜索用时 203 毫秒
611.
D Nakagawa Y Ohshima M Takusagawa N Ikota Y Takahashi S Shimizu T Ozawa 《Chemical & pharmaceutical bulletin》2001,49(12):1547-1554
The redox reaction of cytochrome c after modification with peroxynitrite under physiological conditions was investigated. Cytochrome c was treated with a bolus of synthetic peroxynitrite at a sub-millimolar concentration, and then subjected to reduction by superoxide and oxidation by hydrogen peroxide. The ability for the membrane potential formation in the mitochondrial respiratory chain was also evaluated. After the treatment with peroxynitrite, the cytochrome c molecule was mono-nitrated mainly at a tyrosine residue, using liquid chromatography-electrospray ionizing mass spectrometry (LC-ESI-MS) and HPLC. Although the redox capacity of cytochrome c was not affected by the peroxynitrite treatment, the oxidation of ferrocytochrome c to ferricytochrome c by hydrogen peroxide was accelerated. When cytochrome c was treated with peroxynitrite in the presence of 5-methoxytryptamine, an inhibitor for the tyrosine nitration by peroxynitrite, the acceleration of hydrogen peroxide-mediated oxidation was suppressed. It was also found that the formation of membrane potential in the rat liver mitochondria was suppressed when peroxynitrite-treated cytochrome c was used instead of the intact cytochrome c in vitro. From these results, we concluded that the peroxynitrite-treated cytochrome c was nitrated at a tyrosine residue and became more susceptible to oxidation by hydrogen peroxide, concomitantly losing the ability to transfer electrons in the mitochondrial respiratory chain. It is suggested that the peroxynitrite-induced modification of cytochrome c increases the susceptibility to non-physiological oxidants, and may cause dysfunction of mitochondria by suppressing of membrane potential. 相似文献
612.
H. En'yo J. Chiba H. Funahashi H. Hamagaki T. Haseyama M. Ieiri M. Ishino H. Kanda S. Mihara T. Miyashita T. Murakami R. Muto M. Naruki M. Nomachi K. Ozawa O. Sasaki M. Sekimoto H. D. Sato T. Tabaru K. Tanaka S. Yamada S. Yokkaichi Y. Yoshimura KEK-PS-E collaboration 《Nuclear Physics A》2000,670(1-4):182-185
The experiment E325 being performed at KEK 12GeV-PS is to investigate the chiral property of QCD in dense matter through the measurements of vector mesons which decay inside nucleus. The status of the experiment and the preliminary mass distribution of Φ → K+K− decays are presented. 相似文献
613.
H. Tamura K. Tanida D. Abe H. Akikawa K. Araki H. Bhang T. Endo Y. Fujii T. Fukuda O. Hashimoto K. Imai H. Hotchi Y. Kakiguchi J. H. Kim Y. D. Kim T. Miyoshi T. Murakami T. Nagae J. Nishida H. Noumi H. Outa K. Ozawa T. Saito J. Sasao Y. Sato S. Satoh R. Sawafta M. Sekimoto T. Takahashi L. Tang H. H. Xia S. H. Zhou L. H. Zhu 《Nuclear Physics A》2000,670(1-4):249-256
We report on the first observation of hypernuclear γ transitions using germanium detectors. Using a large-acceptance Ge detector system, we observed two γ transitions in Λ7Li, the spin-flip
transition at 689±4keV and the
transition at 2050±2 keV (preliminary). The strength of the ΛN spin-spin interaction is derived from the energy of the former transition. As for the latter transition, B(E2) was measured to be 3.9±0.6±0.4 e2fm4 (preliminary), which indicates a shrinkage of the nuclear size of Λ7Li from 6Li and confirms “glue-like role” of Λ. 相似文献
614.
Makoto Ozawa 《Proceedings of the American Mathematical Society》2000,128(3):919-922
We give a necessary and sufficient condition for knots to bound incompressible non-free Seifert surfaces.
615.
Matsuta K. Onishi T. Fukuda M. Minamisono T. Akai H. Sasaki M. Yamaguchi T. Miyake T. Sato K. Minamisono K. Ohsumi F. Muramoto Y. Oui S. Ha C. Tanaka K. Kidera K. Morishita A. Kitagawa A. Torikoshi M. Kanazawa M. Nishio T. Koda S. Ohtsubo T. Fukuda S. Nojiri Y. Momota S. Ozawa A. Yoshida K. Suzuki T. Kobayashi T. Tanihata I. Hanna S.S. Alonso J.R. Krebs G.F. Symons T.J.M. 《Hyperfine Interactions》1999,120(1-8):673-677
The β-NMR spectra of 21F, 23Mg, 27Si and 39Ca which were produced in heavy ion collisions and implanted in various crystals have been observed. The magnetic moments
of 21F and 27Si were determined to be |μ(21F)| = 3.9194 ± 0.0012 μN and |μ(27Si)| = 0.8653 ± 0.0003 μN, respectively. The electric quadrupole coupling constants were determined for the first time to be |eqQ(21F in MgF2)/h|= 9.94 ± 0.09 MHz, |eqQ(23Mg in MgF2)/h|= 1.96 ± 0.06 MHz, |eqQ(27Si in Al2O3)/h|= 1.90 ± 0.12 MHz, |eqQ(39Ca in CaCO3)/h|= 0.60 ± 0.04 MHz. From the present eqQ/h, the Q moments were deduced as |Q(21F)|= 110 ± 22 mb, |Q(23Mg)|= 114 ± 3 mb, |Q(27Si)|= 60 ± 13 mb and |Q(39Ca)|= 36± 7 mb. The present data were compared with the theoretical values obtained by the OXBASH shell model code.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
616.
Tomohiko Inomata Mayuka Hatano Yuya Kawai Ayaka Matsunaga Takuma Kitagawa Yuko Wasada-Tsutsui Tomohiro Ozawa Hideki Masuda 《Molecules (Basel, Switzerland)》2021,26(22)
To develop low-cost and efficient dye-sensitized solar cells (DSSCs), we designed and prepared three homoleptic Cu(I) complexes with asymmetric ligands, M1, M2, and Y3, which have the advantages of heteroleptic-type complexes and compensate for their synthetic challenges. The three copper(I) complexes were characterized by elemental analysis, UV-vis absorption spectroscopy, and electrochemical measurements. Their absorption spectra and orbital energies were evaluated and are discussed in the context of TD-DFT calculations. The complexes have high VOC values (0.48, 0.60, and 0.66 V for M1, M2, and Y3, respectively) which are similar to previously reported copper(I) dyes with symmetric ligands, although their energy conversion efficiencies are relatively low (0.17, 0.64, and 2.66%, respectively). 相似文献
617.
618.
Takashi Ikeda Dr. Keishiro Tahara Dr. Ryoichi Ishimatsu Prof. Toshikazu Ono Dr. Luxia Cui Momoka Maeda Prof. Yoshiki Ozawa Prof. Masaaki Abe 《Angewandte Chemie (International ed. in English)》2023,62(21):e202301109
This study reports an effective peripheral decoration of organic donor-acceptor diads with B(C6F5)3 for stabilizing electrogenerated radical ions. By employing a common p-type organic semiconductor benzothienobenzothiophene (BTBT) as the donor, tetracoordinate boron complexes showed improved solution electrochemiluminescence (ECL) intensity, reaching a 156-fold increase compared to that of the parent diad. The unprecedented Lewis-pairing-induced ECL enhancement is attributed to the multiple roles of B(C6F5)3: 1) redistributing frontier orbitals, 2) facilitating electrochemical excitation, and 3) restricting molecular motions. Furthermore, B(C6F5)3 converted the molecular arrangement of BTBT from conventional 2D herringbones into 1D π-stacks. This robust, highly ordered columnar nanostructure allowed red-shifting of the crystalline film ECL with electrochemical doping through the electronic coupling pathways of BTBT. Our approach will facilitate the development of elaborate metal-free ECL systems. 相似文献
619.
Dr. Koki Ikemoto Kanato Takahashi Prof. Dr. Takeaki Ozawa Prof. Dr. Hiroyuki Isobe 《Angewandte Chemie (International ed. in English)》2023,62(14):e202219059
“How do we decide the stoichiometry of host–guest complexes?” This question has long been answered by the Job plot since its first report in 1928. However, as the Job plot was claimed to be misleading in 2016, the question became an open question again and called for renewed investigations. An information-theoretic approach, called Akaike's information criterion, is introduced in this study to select the best model of host–guest complexes, which can rank the models with weight of evidence. A few test cases with unique cylindrical hosts were examined to demonstrate the applicability of the information-theoretic method. Consequently, reasonable views over the thermodynamic behaviors of dumbbell-and-cylinder complexes were obtained. Akaike's information criterion can be a useful and superior alternative to statistical null hypothesis testing, which was proposed as a remedy in place of the Job plot. 相似文献
620.
Yasuhiro Hayakawa Masahiko Ando Tadanobu Koyama Masashi Kumagawa Tetsuo Ozawa Miyuki Masaki Katsumi Takahashi 《Crystal Research and Technology》1996,31(5):567-575
InxGa1-xAs (x = 0.045) ternary bulk crystals were grown on GaAs seeds from an In–Ga–As solution by the temperature-difference method modified to rotate a growth ampoule. The effect of ampoule rotation on the profiles of the composition and the growth rate were investigated. The In compositional profiles were uniform irrespective of the ampoule rotation. On the other hand, the growth rate at the center of the crystal increased from 40 μm/h at 0 rpm to 55 μm/h at 100 rpm. The profile of growth rate changed from concave to convex toward the seed due to the ampoule rotation. Flow patterns and compositional profiles in the solution were simulated by solving four equations: Navier-Stokes, continuity, energy, and solute diffusion. The ampoule rotation enhanced the transportation of As component from the GaAs feed toward the seed at the central region in the solution. This led to the increase of the growth rate. 相似文献