全文获取类型
收费全文 | 129篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 60篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 2篇 |
物理学 | 67篇 |
出版年
2021年 | 4篇 |
2019年 | 1篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 6篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有131条查询结果,搜索用时 78 毫秒
1.
The synthesis of rigid spirocyclic bislactams derived from pyroglutamic acid has been established. 相似文献
2.
Using a simulation technique introduced recently, we study winding clusters in percolation on the torus and the Möbius strip for different aspect ratios. The asynchronous parallelization of the simulation makes very large system and sample sizes possible. Our high accuracy results are fully consistent with predictions from conformal field theory. The numerical results for the Möbius strip and the number distribution of winding clusters on the torus await theoretical explanation. To our knowledge, this study is the first of its kind. 相似文献
3.
KL Britton HF Rogers Y Asano T Dairi Y Kato TJ Stillman DW Rice 《Acta crystallographica. Section D, Biological crystallography》1998,53(4):124-126
The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres. 相似文献
4.
5.
Catherine E. Davies Thomas D. Heightman Stephen A. Hermitage Mark G. Moloney 《合成通讯》2013,43(4):687-696
Short, convenient syntheses of racemic and enantiopure methyl 6-oxopipecolate are described, starting from either pipecolic acid or (S)-lysine respectively. The sequence for the latter compound relies upon improved methodology for the oxidation of C-6 of lysine. 相似文献
6.
The possibility of simultaneous induction and detection, with an intense single mode ir laser, of the Autler Townes splittings of certain rovibrational lines in diatomics is discussed. A model based on the accurately known molecular parameters and dipole matrix elements of CO is used to exhibit the power splitting effect for the case of two quantum excitation. The power splitting effect, which exhibits a threshold as a function of laser intensity is clearly discernable in both the two and one quantum absorption profiles as well as in the total absorption spectrum. Using a simple qualitative rule we predict that such rovibrational line splittings should also be observable in an analogous set of transitions in other diatomics. 相似文献
7.
Li L Schülzgen A Temyanko VL Qiu T Morrell MM Wang Q Mafi A Moloney JV Peyghambarian N 《Optics letters》2005,30(10):1141-1143
We report fabrication and testing of the first phosphate glass microstructured fiber lasers with large Er-Yb-codoped cores. For an 11-cm-long cladding-pumped fiber laser, more than 3 W of continuous wave output power is demonstrated, and near single-mode beam quality is obtained for an active core area larger than 400 microm2. 相似文献
8.
9.
Generation of watt-level single-longitudinal-mode output from cladding-pumped short fiber lasers 总被引:1,自引:0,他引:1
Qiu T Suzuki S Schülzgen A Li L Polynkin A Temyanko V Moloney JV Peyghambarian N 《Optics letters》2005,30(20):2748-2750
We generate as much as 1.6 W of continuous-wave 1550 nm single-longitudinal-mode output from a cladding pumped Er-Yb codoped phosphate fiber laser. This power is to our knowledge among the highest in single-longitudinal-mode fiber lasers. The narrowband fiber Bragg grating output coupler is demonstrated to be an effective element for providing the single-longitudinal-mode selection. 相似文献
10.
A recent experiment [Appl. Phys. Lett. 83, 213 (2003)] indicated that filaments created in femtosecond high-power pulses propagating in air are surprisingly robust when interacting with microscopic water droplets. We present numerical modeling of the dynamics of the filament-droplet interaction. Our simulation results provide further insight into the interplay between the filament's core and the wide transverse pedestal of the pulse. It is shown that the robustness of the filament comes from the transverse low-intensity pedestal that controls the formation of the central hot spot. Implications for penetration of wide, high-power beams through obscurants are discussed. 相似文献