全文获取类型
收费全文 | 84篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 14篇 |
力学 | 2篇 |
数学 | 8篇 |
物理学 | 63篇 |
出版年
2021年 | 1篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有87条查询结果,搜索用时 22 毫秒
31.
Adler J Becker JJ Blaylock GT Bolton T Brient JC Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Cook V Coward DH Dorfan DE Drinkard J Dubois GP Duncan AL Eigen G Einsweiler KF Eisenstein BI Freese T Gatto C Gladding G Grab C Hamilton RP Hauser J Heusch CA Hitlin DG Izen JM Köpke L Li A Lockman WS Mallik U Matthews CG Mincer A Mir R Mockett PM Mozley RF Nemati B Odian A Parrish L Partridge R Perrier J Pitman D Plaetzer SA Richman JD Sadrozinski HF Scarlatella M Schalk TL 《Physical review D: Particles and fields》1989,40(11):3788
32.
Adler J Becker JJ Blaylock GT Bolton T Brient JC Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Cook V Coward DH DeJongh F Dorfan DE Drinkard J Dubois GP Eigen G Einsweiler KF Eisenstein BI Freese T Gatto C Gladding G Grab C Hamilton RP Hauser J Heusch CA Hitlin DG Izen JM Kim PC Köpke L Li A Lockman WS Mallik U Matthews CG Mincer A Mir R Mockett PM Nemati B Odian A Parrish L Partridge R Pitman D Plaetzer SA Richman JD Sadrozinski HF Scarlatella M Schalk TL Schindler RH Seiden A 《Physical review D: Particles and fields》1989,40(3):906-908
33.
P. MORLIÉRE M. BAZIN L. DUBERTRET R. SANTUS T. SA E. MELO G. HÜPPE J. HAIGLE P. FORLOT A. BERNARD 《Photochemistry and photobiology》1991,53(1):13-19
5-Geranoxypsoralen, commonly called bergamottin, a major furocoumarin contained in bergamot oil, is reported in vitro as a highly photoreactive psoralen. In ethanol, it exhibits quite a high triplet state quantum yield (approximately 0.37). The triplet state is involved in subsequent photochemistry which depends on the initial concentration and on the presence of oxygen. In contrast to most psoralens, absorption and fluorescence data suggest that 5-geranoxypsoralen does not interact with DNA in the dark. No UVA-induced interstrand cross-links in DNA were shown. 相似文献
34.
For a class of retarded linear differential equations with solutions of exponential form, it is shown that L
p
-perturbations leave the solutions of the same form. As a particular example, the asymptotic integration of a class of differential
equations is obtained.
(Received 10 August 1998) 相似文献
35.
Liu X Bigioni TP Xu Y Cassell AM Cruden BA 《The journal of physical chemistry. B》2006,110(41):20102-20106
We have grown a dense array of vertically aligned carbon nanotubes (CNTs) with a controlled distribution of diameters by using block copolymer micelles to form and pattern catalyst particles. The block copolymer poly(styrene-block-acrylic acid) (PS16500-PAA4500) was dissolved in toluene to form micelles and then loaded with FeCl3. The metal-loaded micelles were spin-coated on Si and then thermally treated to remove the polymer. Using this process, we produced surfaces patterned with iron oxide catalyst particles with particle densities ranging from 1400 microm(-2) to 3800 microm(-2) and a size distribution of (6.9 +/- 0.8) nm. CNT growth by thermal chemical vapor deposition was then performed on these samples. The low-density catalyst sample produced unaligned, low-density CNTs, whereas the high-density catalyst sample produced vertically aligned, dense CNTs about 10 microm in length. Transmission electron microscopy revealed that the CNTs typically had double and triple graphitic layers with normally distributed diameters of (4.5 +/- 1.1) nm. For comparison, CNTs grown from the standard approach of blanket Fe films had a wide distribution of diameters between 6 and 21 nm. This catalyst preparation approach dramatically sharpens the size distribution of CNTs, compared to standard approaches, and provides a simple means of controlling the areal density of CNTs. 相似文献
36.
ER Badman GE Patterson JM Wells RE Santini RG Cooks 《Journal of mass spectrometry : JMS》1999,34(8):889-894
Dual-detector differential non-destructive Fourier transform detection in a quadrupole ion trap is shown to improve signal intensity and reduce noise compared with spectra recorded using a single detector. A larger area detector in each end-cap electrode is machined to fit its hyperbolic shape and so minimize field imperfections on the z-axis. Argon, acetophenone and bromobenzene spectra were recorded to allow a comparison between single- and dual-detector (differential) modes of detection and to demonstrate the improvement achieved with differential detection. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
37.
Isoxazolidines serve as intermediates in the synthesis of natural products. In addition, they can display significant biological activity, much of which derives from their ability to act as nucleoside analogues. As a result, considerable effort has been applied toward the asymmetric synthesis of isoxazolidines. However, a rapid and straightforward method for determination of the absolute configuration of isoxazolidines has not yet been reported. Herein we report the application of Mosher derivatives for the determination of the absolute configuration of substituted isoxazolidines. The Mosher derivatives exhibit conformational behavior similar to the Mosher derivatives of cyclic secondary amines. Interpretation of the chemical shift anisotropy, with these conformational biases in mind, can be used for the assignment of the absolute configuration of substituted isoxazolidines. 相似文献
38.
An approach to assemble multilayers of carbon nanotubes on a substrate is resented. Chemical vapor deposition using a transition metal catalyst formulation is used to grow the nanotubes. Results show a bilayer assembly of nanotubes each with a different density of tubes. 相似文献
39.
40.
J.S. Cassell 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,104(3):400-427
We construct an integral equation for the flux intensity in a scattering and absorbing two-region turbid spherical medium using the integro-differential form of the radiative transfer equation. The sphere is uniformly irradiated by an external source of arbitrary angular distribution and contains a distributed volume source. Anisotropic scattering is accounted for by the transport approximation. The Fresnel boundary conditions, which incorporate reflection and refraction, are used at the outer surface and at the interface between the two regions. In this respect, some new interfacial boundary conditions are introduced. For the special case of a non-scattering medium, we obtain exact solutions for specular reflection. Some numerical examples are given which show qualitative agreement with some recent work of other authors. Of particular interest are the emergent angular distribution and the albedo of the surface as a function of the refractive index and the radii of the two regions. We also draw attention to the fact that the boundary conditions at the interface differ according to the relative values of the refractive indices in the two regions. The interfacial boundary conditions for use in diffusion theory are derived and compared with those of Aronson [Boundary conditions for diffusion of light. J opt Soc Am 1995;12:2532]. In appendix B, we show how diffusion theory may be used to include scattering into the problem in a simple way. 相似文献