全文获取类型
收费全文 | 1107篇 |
免费 | 19篇 |
国内免费 | 4篇 |
专业分类
化学 | 631篇 |
晶体学 | 6篇 |
力学 | 7篇 |
数学 | 142篇 |
物理学 | 344篇 |
出版年
2021年 | 8篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2016年 | 18篇 |
2015年 | 10篇 |
2014年 | 20篇 |
2013年 | 32篇 |
2012年 | 30篇 |
2011年 | 47篇 |
2010年 | 21篇 |
2009年 | 40篇 |
2008年 | 46篇 |
2007年 | 58篇 |
2006年 | 29篇 |
2005年 | 38篇 |
2004年 | 31篇 |
2003年 | 22篇 |
2002年 | 35篇 |
2001年 | 30篇 |
2000年 | 25篇 |
1999年 | 23篇 |
1998年 | 20篇 |
1997年 | 14篇 |
1996年 | 35篇 |
1995年 | 19篇 |
1994年 | 22篇 |
1993年 | 24篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 19篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 16篇 |
1982年 | 19篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1979年 | 24篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1967年 | 5篇 |
1961年 | 5篇 |
1882年 | 7篇 |
排序方式: 共有1130条查询结果,搜索用时 0 毫秒
111.
112.
J. G. Körner K. Schilcher M. Wirbel Y. L. Wu 《Zeitschrift fur Physik C Particles and Fields》1990,48(4):663-671
We study various transition form factors in semi-leptonic decays ofD-,D s -,B- andB s -mesons using the pole dominance assumption. The vector current form factor is found to have only a negligible contribution to the decay rates involving pseudoscalar to vector transitions. In view of this fact we evaluate the form factors from present experimental data on the exclusive semi-leptonic decay rateΓ and the ratioΓ l /Γ T of the longitudinal and transverse partial decay rates. Some non-leptonic two-body decay rates are also investigated using the factorization ansatz. Consistency with the semi-leptonic decays is found. The transition form factors of theD- andD s -mesons are found to contradict the predictions of quark model. In contrast, the experimental data on the transition form factors ofB-mesons are found to be consistent with the quark model predictions. The KM matrix element |V cb | is determined to be |V cb |=0.040±0.010, a value somewhat smaller than is usually chosen. 相似文献
113.
Fleischer A Wörner HJ Arissian L Liu LR Meckel M Rippert A Dörner R Villeneuve DM Corkum PB Staudte A 《Physical review letters》2011,107(11):113003
We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne+ relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10(15) W/cm2. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime. 相似文献
114.
Magdalena Ulmeanu Iuliana Iordache Mihaela Filipescu Valentin Craciun Simona Cinta Pinzaru Andreas Hörner 《Central European Journal of Physics》2011,9(5):1280-1287
Experimental studies on patterning hexagonal Ge nanostructures have been conducted on Si substrates through deposition of
Ge with colloidal particles as a mask. The deposited Ge thin film possesses, according to the X-ray diffraction measurements,
in plane texture, being epitaxial and aligned with the (111) Si substrate. The size distribution of the patterned Ge nanostructures
is narrow, as indicated by the atomic force microscopy and scanning electron microscopy measurements. We have obtained Ge
nanostructures with lateral dimension of 490 nm (height 12 nm), 200 nm (height 6 nm) and 82 nm (height 6 nm) by using different
sizes of polystyrene spheres. We have performed in depth studies of the Ge nanostructures’ behavior due to thermal and rapid
thermal post-annealing processes. FT micro-Raman spectroscopy shows that there is no Si intermixing during the annealing process.
In order to quantify the changes in the height and lateral dimension, we have performed atomic force microscopy and white
light interferometry analysis. The changes in shape and the decrease in the area of a cross-section of Ge nanostructure will
be discussed in respect to similar results shown in the literature for Ge thin films during the annealing process. 相似文献
115.
Willers T Cezar JC Brookes NB Hu Z Strigari F Körner P Hollmann N Schmitz D Bianchi A Fisk Z Tanaka A Tjeng LH Severing A 《Physical review letters》2011,107(23):236402
We have been able to induce a linear dichroic signal in the Yb M(5) x-ray absorption white line of cubic YbInNi(4) by the application of a magnetic field. The nonzero integrated intensity of the magnetic field induced dichroic spectrum indicates a net noncubic 4f orbital polarization. A quantitative analysis of the temperature and field strength dependence establishes that the crystal-field ground state is a Γ(8) quartet. The results demonstrate the potential of magnetic field induced linear dichroism as a new powerful approach for the investigation of the degeneracy and orbital degrees of freedom of cubic heavy-fermion and Kondo systems. 相似文献
116.
Received June 24, 1997 相似文献
117.
118.
G. Beier J. Friese W. Henning P. Kienle H. J. Körner W. Wagner W. A. Mayer W. Mayer 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(2):217-222
Strongly damped collisions were studied in uranium induced reactions on110Pd and124Sn target nuclei near the barrier. The excitation-energy splitting was deduced from binary reaction yields and those in which the heavy fragment undergoes sequential fission. For systems with 87≦Z≦95 for the heavy fragment, the excitation energy is concentrated in the lighter nucleus, at best shared equally. The results indicate a non-equilibrated energy dissipation, and support nucleon exchange based on average single-particle strength functions as the underlying dissipation mechanism at the barrier. 相似文献
119.
We present a calculation of the B0-B(-)0 mixing matrix element in the framework of QCD sum rules for three-point functions. We compute alpha(s) corrections to a three-point function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element with next-to-leading order (NLO) accuracy. This calculation is imperative for a consistent evaluation of experimentally measured mixing parameters since the coefficient functions of the effective Hamiltonian for B0-B(-)0 mixing are known at NLO. We find that radiative corrections violate factorization at NLO; this violation is under full control and amounts to 10%. The resulting value of the B parameter is found to be B(B)(m(b))=1+0.1(PT)-0.05(non-PT). 相似文献
120.