全文获取类型
收费全文 | 132篇 |
免费 | 3篇 |
专业分类
化学 | 63篇 |
力学 | 12篇 |
数学 | 7篇 |
物理学 | 53篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 4篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有135条查询结果,搜索用时 0 毫秒
131.
132.
133.
134.
A. N. Didenko A. E. Shikanov V. I. Rashchikov V. I. Ryzhkov V. L. Shatokhin 《Technical Physics》2014,59(6):904-910
The generation of neutron pulses with a duration of 1–100 ns using small vacuum accelerating tubes is considered. Two physical models of acceleration of short deuteron bunches in pulse neutron generators are described. The dependences of an instantaneous neutron flux in accelerating tubes on the parameters of pulse neutron generators are obtained using computer simulation. The results of experimental investigation of short-pulse neutron generators based on the accelerating tube with a vacuum-arc deuteron source, connected in the circuit with a discharge peaker, and an accelerating tube with a laser deuteron source, connected according to the Arkad’ev-Marx circuit, are given. In the experiments, the neutron yield per pulse reached 107 for a pulse duration of 10–100 ns. The resultant experimental data are in satisfactory agreement with the results of computer simulation. 相似文献
135.
A. Yu. Teterin M. V. Ryzhkov Yu. A. Teterin K. I. Maslakov T. Reich S. L. Molodtsov 《Journal of Structural Chemistry》2011,52(2):295-303
The structure of the resonant electron emission (REE) spectra of UO2 (REE appears under the excitation with synchrotron radiation near the O4,5(U) absorption edge at ∼100 eV and ∼110 eV) is studied with regard to the X-ray O4,5(U) absorption spectrum of UO2 and a quantitative scheme of molecular orbitals based on the X-ray electron spectroscopy data and the results of a relativistic
calculation of the electronic structure of UO2. The structure of the REE spectra of U3O8 and UO2+x
is studied for comparison, and the effect of the uranium chemical environment in oxides on it is found. The appearance of
such a structure reflects the processes of excitation and decay involving the U5d and electrons of the outer valence MOs (OVMOs,
from 0 to ∼13 eV) and inner valence MOs (IVMOs, from ∼13 eV to ∼35 eV) of the studied oxides. It is noted that REE spectra
show the partial density of states of U6p and U5f electrons. Based on the structure of REE spectra, it is revealed that U5f electrons directly participate (without losing the f nature) in the chemical bonding of uranium oxides and are delocalized within CMOs (in the middle of the band), which results
in the enhancement of the intensity of the REE spectra of CMO electrons during resonances. The U6d electrons are found to be localized near the bottom of the outer valence band and are observed in the REE spectra of the
studied oxides as a characteristic maximum at 10.8 eV. It is confirmed that U6p electrons are effectively involved in the formation of IVMOs, which leads to the appearance of the structure in the region
of IVMO electron energies during resonances. This structure depends on the chemical environment of uranium in the considered
oxides. 相似文献