全文获取类型
收费全文 | 210篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
化学 | 133篇 |
晶体学 | 3篇 |
力学 | 4篇 |
数学 | 4篇 |
物理学 | 75篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 10篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有219条查询结果,搜索用时 140 毫秒
151.
Caballero JB Puertas AM Fernández-Barbero A Javier de Las Nieves F Romero-Enrique JM Rull LF 《The Journal of chemical physics》2006,124(5):054909
The liquid-gas transition of an electroneutral mixture of oppositely charged colloids, studied by Monte Carlo simulations, is found in the low-temperature-low-density region. The critical temperature shows a nonmonotonous behavior as a function of the interaction range, kappa(-1), with a maximum at kappasigma approximately 10, implying an island of coexistence in the kappa-rho plane. The system is arranged in such a way that each particle is surrounded by shells of particles with alternating charge. In contrast with the electrolyte primitive model, both neutral and charged clusters are obtained in the vapor phase. 相似文献
152.
Zhang Y Song Y Yin F Broderick E Siegel K Goddard A Nieves E Pasa-Tolic L Tanaka Y Wang H Morita CT Oldfield E 《Chemistry & biology》2006,13(9):985-992
Human gammadelta T cells containing the Vgamma2Vdelta2 (Vgamma9Vdelta2) T cell receptor are stimulated by a broad variety of small, phosphorus-containing antigenic molecules called phosphoantigens. The structures of several species present in both Mycobacteria (TUBags1-4) and in Escherichia coli have been reported to contain a formyl-alkyl diphosphate core. Here we report the synthesis of the lead member of the series, 3-formyl-1-butyl diphosphate. This compound has low activity for gammadelta T cell stimulation, unlike its highly active isomer (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate, necessitating a revision of the structure of TUBag1. Likewise, the structure of the species identified as the pentyl analog (TUBag 2) is revised to 6-phosphogluconate. These results indicate that neither TUBag1 nor the m/e 275 species proposed for TUBag2 are 3-formyl-1-alkyl diphosphates, leading to the conclusion that none of the natural phosphoantigens (TUBags1-4) possess the structures reported previously. 相似文献
153.
Antonia Garrido Frenich María de las Nieves Barco Bonilla Juan Carlos López Martínez José Luis Martínez Vidal Roberto Romero‐González 《Journal of separation science》2009,32(9):1383-1389
Di‐(2‐ethylhexyl)phthalate (DEHP) was determined in environmental samples such as water and soil. DEHP was extracted from water samples using SPE, whereas for soils pressurized liquid extraction was applied as extraction method, using hexane/acetone (1:1, v/v) as extractant solvent. The use of HPLC coupled to MS provides the basis of the selective determination of DEHP in the analyzed samples. The extraction procedures were validated and good results were found. Recoveries were ranged from 86.0 to 99.8% with RSD lower than 18% and LODs were 0.02 mg/kg and 0.03 μg/L for soils and water, respectively. Finally, the optimized methods were applied to the analysis of real samples and DEHP was not found above the LOQ (0.05 mg/kg) in soil samples whereas it was detected in water samples at concentrations ranging between 0.19 to 0.88 μg/L. 相似文献
154.
The energies and widths of several D0 meson bound states for different nuclei are obtained using a D -meson selfenergy in the nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized coupled-channel theory. The kernel of the meson–baryon interaction is based on a model that treats heavy pseudoscalar and heavy vector mesons on equal footing, as required by heavy quark symmetry. We find D0 bound states in all studied nuclei, from 12C up to 208Pb. The inclusion of vector mesons is the keystone for obtaining an attractive D –nucleus interaction that leads to the existence of D0–nucleus bound states, as compared to previous studies based on SU(4) flavor symmetry. In some cases, the half widths are smaller than the separation of the levels, what makes possible their experimental observation by means of a nuclear reaction. This can be of particular interest for the future P?ANDA@FAIR physics program. We also find a D+ bound state in 12C, but it is too broad and will have a significant overlap with the energies of the continuum. 相似文献
155.
L. Tolos D. Gamermann C. Garcia-Recio R. Molina J. Nieves E. Oset A. Ramos 《中国物理 C》2010,34(9):1335-1338
We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner.We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions.We discuss the implications of the in-medium properties of open-charm mesons on the D s0 (2317) and the predicted X(3700) scalar resonances. 相似文献
156.
We analyze the effects of hyperfine mixing in b → c semileptonic decays of doubly heavy baryons.We qualitatively confirm the results by W.Roberts and M.Pervin in Int.J.Mod.Phys.A,2009,24: 2401– 2413,finding that mixing has a great impact on those transitions.However,predictions without mixing differ by a factor of 2 and this discrepancy translates to the mixed case where large differences in decay widths are observed between the two calculations. 相似文献
157.
We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the DsO(2317) and the predicted X(3700) scalar resonances. 相似文献
158.
We study charmed baryon resonances that are generated dynamically from a coupled-channel unitary approach that implements heavy-quark symmetry. Some states can already be identified with exper-imental observations, such as Λ_c(2595), Λ_c(2660), Σ_c(2902) or Λ_c(2941), while others need a compilation of more experimental data as well as an extension of the model to include higher order contributions. We also compare our model to previous SU(4) schemes. 相似文献
159.
C. Albertus J. M. Flynn E. Hernández J. Nieves J. M. Verde-Velasco 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):725-727
The semileptonic decay B→π is studied starting from a simple quark model that takes into into account the effect of the B*-resonance. A novel, multiply subtracted, Omnès dispersion relation has been implemented to extend the predictions of the
quark model to all q2 values accessible in the physical decay. By comparison to the experimental data, we extract | V
ub| = (3.4±0.2(exp.)±0.7(theory))0-3. As a further test of the model, we have also studied D→π and D→K decays for which we get good agreement with experiment. 相似文献
160.