全文获取类型
收费全文 | 110篇 |
免费 | 25篇 |
国内免费 | 48篇 |
专业分类
化学 | 27篇 |
力学 | 2篇 |
数学 | 2篇 |
物理学 | 152篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 10篇 |
2010年 | 2篇 |
2009年 | 15篇 |
2008年 | 9篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 15篇 |
2002年 | 9篇 |
2001年 | 17篇 |
2000年 | 12篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有183条查询结果,搜索用时 15 毫秒
1.
讨论了横向位移双曝光散斑图维纳谱的信息分布,并由此导出杨氏纹图的一般表达式。讨论了条纹可见度与应变,面内转动,照明光束直径与条纹图图空间坐标的关系,指出了在条纹可见度影响下最大可见条纹数目。还讨论了散斑衬比与衍射晕的关系。 相似文献
2.
测量了27,28P和相应同中子异位素在28Si靶上的中能反应截面.测得N=12和13同中子异位素的反应截面在Z=15处突然增大.对Z≤14同中子异位素和28P的实验数据结果可以用改进的光学极限近似的Glauber理论很好地描述.28P的反应截面能够用扩大核芯以改进的Glauber理论来解释.但是,用改进光学极限和少体近似的Glauber理论却低估了27P的实验数据.理论分析表明,扩大的核芯加质子晕可能是响应27P+28Si反应截面增强的机制. The reaction cross sections of~(27,28)P and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at Z=15. The experimental results for the isotones with Z≤14 and~(28)P can be described well by the modified Glauber theory of the optical limit approach. The enhancement of the reaction cross section for~(28)P could be explained by the modified Glauber theory with an enlarged core. Theoretical ana... 相似文献
3.
The Complexes [Pd(PEt
3)2
dtc]X (1) and Pd(PR
3)Xdtc (2, 3) (dtc=S2CNEt
3;X=Cl, Br, I;R=Et, Ph) have been prepared. Conductivity, susceptibility, UV and IR measurements show that the cations [Pd(PEt
3)2
dtc]+ of1 and the complexes2, 3 have square-planar structure. 相似文献
4.
Moses Salci Evgeny Yarevsky Sergey B. Levin Nils Elander 《International journal of quantum chemistry》2007,107(2):464-468
A three‐dimensional finite element method is applied to the ground states of the symmetric and asymmetric atomic helium trimers 4He3 and 4He2–3He. Three different He–He interaction potentials of hard‐core nature were studied. Two extrapolation procedures based on the convergence properties of the finite element method are investigated. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
5.
Properties of the even-N Zr isotopes and their corresponding single-Λ and double-Λ hypernuclei are studied in the deformed Skyrme-Hartree-Fock approach. Binding energy, the two-neutron separation energies, radii are studied from beta-stable zone to the neutron drip line in this paper. The neutron drip line nuclei predicted with SLy4 and SkI4 interactions are 122Zr and 138Zr, respectively. The neutron drip line of single-Λ and double-Λ hypernuclei are 139ΛZr and 1422ΛZr with SkI4 interaction, respectively. The predicted hyperon drip line hypernuclei with 80Zr and 138Zr cores are 10020ΛZr and 18850ΛZr, respectively. 相似文献
6.
H. Karimian 《Journal of Dispersion Science and Technology》2013,34(4):457-464
Dispersion behavior of colloidal Al2O3 aqueous suspensions was investigated in the presence of highly charged CeO2 nanoparticles and polymeric additives. It was found that among the investigated parameters, ceria nanoparticles concentration had the highest significant effect on the stability of Al2O3-CeO2 suspensions. However, the low influence of dispersant concentration may be due to significant role of ceria nanoparticles stabilizing alumina microspheres by “nanoparticle halo” formation. The stabilization of the bidispersed suspensions was also evidenced by scanning electron microscopy and elemental analysis of the sediment layers after three weeks. 相似文献
7.
K. C. Rajanna N. Maasi Reddy M. Rajender Reddy P. K. Saiprakash 《Journal of Dispersion Science and Technology》2013,34(4):613-616
A Novel Hunsdiecker‐Borodin reaction (HBR) has been carried out efficiently with α,β‐unsaturated aliphatic and aromatic carboxylic acids by using N‐halo succinimides such as N‐chloro succinimide (NCS), N‐bromo succinimide (NBS), and N‐iodo succinimide (NIS) under micellar media. The reaction with α,β‐unsaturated aromatic carboxylic acids afforded β‐halo styrenes in excellent yield while α,β‐unsaturated aliphatic carboxylic acids underwent decarboxylation and to give corresponding halo derivatives. The reactions are dramatically accelerated in micellar media. This procedure works efficiently in CTAB (cetyl trimethyl ammonium bromide), SDS (sodium dodecyl sulfate), and TX (Triton‐X‐100) media under stirred conditions at room temperature. At reflux temperatures the yield of reaction products were further enhanced from good to excellent. 相似文献
8.
We have calculated the one-neutron absorption cross-section and the longitudinal momentum distribution of the core fragment
coming out from the breakup of 11Be and 19C on 9Be target at 63 MeV/A and 88 MeV/A beam energies respectively. The reaction mechanism is treated within the framework of the
eikonal approximation. The effective range of the nuclear interaction between the core and the valence neutron within the
projectile has been determined by comparing the predicted stripping cross-section with the recently measured one. The effective
range for 19C has been found to be smaller than that for 11Be. It qualitatively indicates that 19C is slightly more halo than 11Be. The smaller width, predicted as well as measured, of the LMD of 18C than 10Be also strengthens this fact. The experimental data concerning the LMD of core fragments have been well represented.
相似文献
9.
10.
采用同位旋相关的Boltzmann—Langevin方程计算了核素^12-15N和^17-20Ne反应中轻带电粒子发射的同位旋效应。^12-15N与^28Si靶的反应结果显示轻带电粒子的产生截面有明显的同位旋效应,^12N的轻带电粒子产生截面突然增大,与实验得出的结论相同,由此检验了所采用的计算方法的可行性。同时还计算了^17-20Ne与^9Be靶的反应,发现^17Ne的轻带电粒子产生截面也是突然增大,并且其质子分布有较大的弥散,据此认为^17Ne可能具有晕结构。 Within the Boltzmann-Langevin equation, the isospin effects on the production cross sections of light charged particles (LCP) in the reaction of proton rich nuclei were studied. We have calculated the LCP productio n cross sections of the reaction ^12-15N + ^28Si at 55 MeV/u and ^17-20Ne + ^9Be at 60 MeV/u. The LCP production cross sections of ^12N increase abnormally in comparison with those of ^13-15N. The result accorded with experimental one. It also happened to ^17-20Ne. It suggests that ^17Ne is probably a proton halo nucleus. 相似文献