全文获取类型
收费全文 | 115篇 |
免费 | 0篇 |
专业分类
化学 | 43篇 |
力学 | 2篇 |
数学 | 8篇 |
物理学 | 62篇 |
出版年
2021年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1962年 | 1篇 |
1961年 | 3篇 |
1960年 | 1篇 |
排序方式: 共有115条查询结果,搜索用时 15 毫秒
101.
Bye-beam excitation of a He/CO mixture the CO(3Π r ,a) state was sufficiently populated to allow the measurement of the absorption spectrum. The (0, 0), (1, 1), (2, 2) and (0, 1) bands of thec 3Π←a 3Π system of CO have been observed and the molecular constantsT e =92036.0 cm?1 (for the band head), ω e =2249.5 cm?1, ω e x e =29.5 cm?1 have been derived for CO(c). A new electronic state withT e =91854.3 cm?1, ω e =848.4 cm?1, ω e x e =9.8 cm?1,B e =1.351 cm?1, and α e =0.021 cm?1 was identified to be a3Σ state. It seems to be very likely that this state is the CO (3pσ,3Σ,j) state discussed in the literature. The results indicate a perturbation of the υ=1 levels of the new state by the CO (c,υ=0) levels. Another strong perturbation is found in the υ=4 levels. The three CO(3Σ,b,υ′=0,1,2)←CO (a,υ″=0) bands were also investigated yielding for CO(b):T e =83778 cm?1, ω e =2335 cm?1, ω e x e =59 cm?1 andB e =1.86 cm?1. 相似文献
102.
S. Markert N. Sahoo T. P. Das M. Mantel H. Langhoff 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,29(2):85-89
The excimer-like ions formed by combining a rare gas ion with an alkali atom were investigated by an ab initio HF-CI calculation. The resulting four bound excited states1Σ+,1Π,3Σ+ and3Π were subjected to a semiempirical spin orbit (SO)-coupling yielding eight fine structure levels with angular momenta Ω=2, 1(3) and 0(4). For (NeLi)+, (NeNa)+, (ArLi)+, (ArNa)+, (ArK)+ and (KrLi)+ the wavelengths for the five allowed transitions to the ground state were calculated. The results are in close agreement with the experimental results. Also other spectroscopic properties as binding energies, transition moments and vibrational quanta are given. 相似文献
103.
A direct problem of applied mathematical modelling is to determine the response of a system given the governing partial differential equations,
the geometry of interest, the complete boundary and initial conditions, and material properties. When one or more of the conditions
for the solution of the direct problem are unknown, an inverse problem can be formulated. One of the methods frequently used for the solution of inverse problems involves finding the values of
the unknowns in a mathematical formulation such that the behavior calculated with the model matches the measured response
to a degree evaluated in terms of the classical L
2 norm. Considered in this sense, the inverse problem is equivalent to an ill-posed optimization problem for the estimation of parameters whose solution in the majority of cases is a real mathematical challenge.
In this contribution, we report a novel approach that avoids the mathematical difficulties inspired by the ill-posed character
of the model. Our method is devoted to the computation of inverse problems furnished by second-order elliptical systems of
partial differential equations and falls in the same conceptual line with the method initiated by Kozlov et al. and further
extended and algorithmized by Weikl et al.
We construct and employ a weak version of the algorithm found by Weikl et al. Proofs for the convergence and regularity of
this version are given for the case of a single layer.
The computational realization of the algorithm (called briefly AICRA) is applied and numerical results are obtained. Comparison
with experiments demonstrates a good significance and representativeness.
__________
Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 12, No. 4, pp. 209–230, 2006. 相似文献
104.
The half-life of the 58keV level of159Tb was determined by classical resonance absorption using the centrifuge technique and by Mössbauer spectroscopy measuring the natural line width and found to beτ 1/2=(58±10)ps. Mössbauer spectra for Tb and Tb2O3 absorbers and for Dy2O3 and GdFe2 sources were investigated for temperatures between 9 and 385 K. Results for hyperfine interactions and Debye Waller factors are given. The Debye Waller factors are compared with predictions obtained from other experimental results. 相似文献
105.
106.
Approximations to Fredholm determinants calculated from the Ritz principle and square-integrable basis functions are interpreted in the context of Stieltjes integration, and shown to provide convergent estimates of elastic scattering phase shifts. 相似文献
107.
W. Schött H. Langhoff L. Frevert A. Flammersfeld 《Zeitschrift für Physik A Hadrons and Nuclei》1967,203(5):443-452
γ-quanta emitted by gaseous Kr79-sources were scattered resonantly from Br79-nuclei. By increasing the density in the source the effective cross section for resonance scattering was influenced due to gaskinetic collisions of the recoiling Br79-nuclei with atoms before emission of theγ-quantum. The cross section for gaskinetic collisions was determined to beσ st=(12.0±1.8) 10?16 cm2 in agreement with the theoretical value obtained from a hard sphere model. This technique, similar to the usual “Doppler shift technique”, yields, if combined with the measurement of the absolute cross section for resonance scattering, spin and lifetime of the levels at 398 and 606 keV. The resonance scattering from the 834 keV level shows an unexpected behaviour in complete contradiction to the hard sphere model, indicating that the velocity of the recoiling nuclei is increased in a dense source atmosphere. 相似文献
108.
R. Sauerbrey J. Liegel E. Schätzlein H. Langhoff 《Applied Physics A: Materials Science & Processing》1981,25(3):283-289
Lasing from e-beam pumped Ar−N2-mixtures at 337, 358, 380, and 406 nm was investigated in a longitudinal pumping geometry. Time dependence, output powers
and energies of the pulses at the different wavelengths were determined as functions of pressure, Ar−N2 ratio and energy input. A kinetic model is proposed that reproduces the experimental data. 相似文献
109.
R. Cesareo H. Langhoff A. Flammersfeld 《Zeitschrift für Physik A Hadrons and Nuclei》1966,197(5):426-434
Theγ spectra of Tc95 (20 h), Tc95m (62 d), and Tc96 (4.3 d) have been investigated using Li-drifted germanium counters. The observedγ transitions in the decay of Tc95 and Tc95m are in agreement with earlier investigations except for 6 transitions at 204, 680, and 840 keV in Tc95 and at 970, 1390, and 1630 keV in Tc95m reported previously which have not been confirmed. In the spectrum of Tc96 new transitions at 437, 462, 1094, 1200, and 1505 keV have been identified. The level scheme of Mo96 is discussed in respect of these results. 相似文献
110.