全文获取类型
收费全文 | 1432篇 |
免费 | 42篇 |
国内免费 | 2篇 |
专业分类
化学 | 1059篇 |
晶体学 | 9篇 |
力学 | 30篇 |
数学 | 59篇 |
物理学 | 319篇 |
出版年
2022年 | 9篇 |
2021年 | 10篇 |
2020年 | 28篇 |
2019年 | 23篇 |
2018年 | 8篇 |
2017年 | 14篇 |
2016年 | 25篇 |
2015年 | 19篇 |
2014年 | 37篇 |
2013年 | 61篇 |
2012年 | 68篇 |
2011年 | 86篇 |
2010年 | 44篇 |
2009年 | 36篇 |
2008年 | 75篇 |
2007年 | 82篇 |
2006年 | 84篇 |
2005年 | 90篇 |
2004年 | 79篇 |
2003年 | 60篇 |
2002年 | 53篇 |
2001年 | 49篇 |
2000年 | 31篇 |
1999年 | 26篇 |
1998年 | 12篇 |
1997年 | 16篇 |
1996年 | 26篇 |
1995年 | 20篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 19篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 18篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1976年 | 12篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 8篇 |
1969年 | 7篇 |
排序方式: 共有1476条查询结果,搜索用时 0 毫秒
111.
Engelbert J. Dockner Kazuo Nishimura 《Journal of Difference Equations and Applications》2013,19(6):915-926
We formulate a class of N player difference games and derive open—loop and Markov equilibria. It turns out that both types of equilibria can be characterized by a set of difference equations that describe the equilibrium dynamics. We analyze the stability properties of the difference equations that correspond to an equilibrium and find that in both the open—loop and the Markov game there is convergence towards a steady state equilibrium 相似文献
112.
Yasuhiro Shiraishi Yugo Furubayashi Go Nishimura Takayuki Hirai 《Journal of luminescence》2007,127(2):623-632
Dinuclear lanthanide (Ln=Tb3+ or Eu3+) complexes (Ln2L2) of two octadentate macrocyclic polyaminopolycarboxylic ligands connected through a benzophenone (BP) moiety (L2) have been synthesized. Sensitized luminescence properties of Ln2L2 in water have been studied in comparison to those of BP-conjugated mononuclear Ln complexes (LnL1). The luminescence intensity of Tb2L2 is lower than that of TbL1 because of lower triplet quantum yield of the BP moiety. In contrast, Eu2L2 shows higher intensity than EuL1. For both Eu complexes, energy level of triplet excited-state BP (3BP*) is only 3 kJ mol−1 higher than that of 5D2 excited-state of Eu3+. The 5D2 state formed by a triplet-energy transfer (TET) from 3BP* is therefore deactivated by a back energy transfer (BET) to the ground-state BP, resulting in low luminescence intensity of EuL1. In contrast, within Eu2L2, TET from 3BP* to 5D0 state of two Eu3+ ions is accelerated, thus leading to higher luminescence intensity. Another notable feature of Eu2L2 is the luminescence quantum yield independent of its concentration. In contrast, for EuL1 system, an intermolecular BET occurs from 5D2 state of Eu3+ to the ground-state BP conjugated to another EuL1 complex, resulting in a yield decrease with the concentration increase. 相似文献
113.
114.
ABSTRACTThe objective of this study was to determine whether sodium caseinate can inhibit the aggregation of whey protein induced by pressure treatment. Solutions of β-lactoglobulin (β-Lg, 0.2%, w/v) and mixtures containing 0.2% (w/v) β-Lg and 0–0.5% (w/v) sodium caseinate (NaCas) were pressurized at 400–800?MPa. NaCas suppressed the aggregation of β-Lg induced by pressure treatment, and this function was dependent on the concentration of NaCas. Furthermore, NaCas altered the aggregation process of β-Lg by suppressing the transition of the aggregate from the soluble phase to the insoluble phase and, as a result, the fraction of insoluble aggregates was decreased. During this process, NaCas formed stable complexes with the denatured β-Lg, and the formation of complexes prevented further aggregation of β-Lg. These results indicate that NaCas exhibits a chaperone-like activity under high pressure. 相似文献
115.
Hirokazu Nishimura 《International Journal of Theoretical Physics》1995,34(2):211-228
The notion of a manual, introduced and investigated in detail by Foulis, Randall, and their followers, has turned out to be further reaching than its originators had envisaged. Its omnipresence is comparable with the notion of a sheaf, whose significance is well recognized by every pure and applied mathematician. The principal concern of this paper is to give an appropriate vehicle, as general as possible, by which the theory of manuals can be developed. The vehicle is called an orthogonal category, which is akin to the notion of a category with coproducts. Orthogonal categories provide also a new perspective on the notion of a sheaf over a complete Boolean algebra, deepening our comprehension of Boolean mathematics and paving the way to quantum mathematics. 相似文献
116.
Beker H Boggild H Boissevain J Cherney M Dodd J Esumi S Fabjan CW Fields DE Franz A Hansen KH Holzer EB Humanic TJ Jacak BV Jayanti R Kalechofsky H Kobayashi T Kvatadze R Lee YY Leltchouk M Lörstad B Maeda N Medvedev A Miake Y Miyabayashi A Murray M Nagamiya S Nishimura S Noteboom E Pandey SU Piuz F Polychronakos V Potekhin M Poulard G Sakaguchi A Sarabura M Shigaki K Simon-Gillo J Sondheim W Sugitate T Sullivan JP Sumi Y van Hecke H Willis WJ Wolf K Xu N 《Physical review letters》1995,74(17):3340-3343
117.
Tetsuya Shimogaki Taihei Ofuji Norihiro Tetsuyama Kota Okazaki Mitsuhiro Higashihata Daisuke Nakamura Hiroshi Ikenoue Tanemasa Asano Tatsuo Okada 《Applied Physics A: Materials Science & Processing》2014,114(2):625-629
The effect of high repetition rate pulsed laser annealing with a KrF excimer laser on the optical properties of phosphorus-ion-implanted zinc oxide nanorods has been investigated. The recovery levels of phosphorus-ion-implanted zinc oxide nanorods have been measured by photoluminescence spectra and cathode luminescence images. Cathode luminescence disappeared over 300 nm below the surface due to the damage caused by ion implantation with an acceleration voltage of 25 kV. When the annealing was performed at a low repetition rate of the KrF excimer laser, cathode luminescence was recovered only in a shallow area below the surface. The depth of the annealed area was increased along with the repetition rate of the annealing laser. By optimizing the annealing conditions such as the repetition rate, the irradiation fluence and so on, we have succeeded in annealing the whole damaged area of over 300 nm in depth and in observing cathode luminescence. Thus, the effectiveness of high repetition rate pulsed laser annealing on phosphorus-ion-implanted zinc oxide nanorods was demonstrated. 相似文献
118.
We developed a continuous-spectrum light beam from Compton backscattering by using coherent synchrotron radiation in an L-band linac at the Kyoto University Research Reactor Institute. The ratio of Compton backscattered photons to background photons when coherent synchrotron radiation was used was three times larger than when coherent transition radiation was used. The transmission spectrum of a polystyrene film in the terahertz-wave region was evaluated by measuring the spectrum of the Compton backscattered photons and it roughly agreed with that measured by a Martin–Puplett-type interferometer. The spectrophotometry using Compton backscattering shows promise as a new tool for investigations in terahertz-wave science. 相似文献
119.
The half wave potential of reduction of Sb5+ in 16Na2O x 10CaO x 74SiO2 glass melts was examined by differential pulse voltammetry up to 1873 K. The half wave potential shifted to the positive direction with an increase in temperature. The results indicate that the equilibrium of Sb5+/Sb3+ shifted to negative direction with an increase in temperature. The half wave potential shifted to positive direction (48 mV at 1473 K) when the atmosphere over the melts changed from pure oxygen gas to air, in agreement with the theoretical prediction. The reversibility of Pt:O2 reference electrode is confirmed. 相似文献
120.