全文获取类型
收费全文 | 24篇 |
免费 | 129篇 |
国内免费 | 59篇 |
专业分类
化学 | 1篇 |
物理学 | 211篇 |
出版年
2022年 | 1篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 10篇 |
2012年 | 15篇 |
2011年 | 11篇 |
2010年 | 18篇 |
2009年 | 18篇 |
2008年 | 21篇 |
2007年 | 24篇 |
2006年 | 22篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1995年 | 3篇 |
1991年 | 3篇 |
1987年 | 1篇 |
排序方式: 共有212条查询结果,搜索用时 31 毫秒
81.
An Empirical Formula Approach to Total Cross Sections for Electron Scattering on Polyatomic Molecules 下载免费PDF全文
Considering the real experimental process of e-molecule scattering a new empirical formula has been developed to calculate the total cross sections (TOSs) for electron scattering on polyatomic molecules (CH4, C2H2, CH3OH and CH3F). The present results are compared with other available theoretical results and experimental data. The new formula incorporates an energy factor f(E) to represent the elastic and inelastic changing process during experiments. It depends on no adjustable parameters and has also extended the validity of the empirical approaches to lower energy range further. 相似文献
82.
Total cross sections (TCSs) for electrons scattering from molecules over a wide energy range are widely used in gaseous lasers, astrophysics, plasma physics, atmospheric physics, and chemical physics, etc.. TCS values repro- duced by analytical or empirical expressions accurately are very useful in computational work related with these applications. Because electron-molecule scattering is a much more complex problem than the corresponding electron-atom scattering, in order to get more accura… 相似文献
83.
利用可加性规则,使用Hartree-Fock波函数,采用由束缚原子概念修正过的复光学势(由静电势、极化势及吸收势三部分组成),在30-3000eV内对正电子被CO,HCl,NH3和SiH4散射的总截面进行了计算,且将计算结果与实验结果及其他理论计算结果进行了比较.结果表明,利用被束缚原子概念修正过的复光学势及可加性规则进行计算,所得结果与实验结果的符合程度要比利用未被束缚原子概念修正的复光学势及可加性规则进行计算得到的结果好很多.因此,在复光学势中采用束缚原子概念可提高正电子被分子散射的总截面的计算准确度. 相似文献
84.
在考虑分子内成键原子间的电子云重叠效应的基础上,提出了一种能够在中、高能区准确计算“电子-分子”散射总截面的修正势方法.利用可加性规则及Hartree-Fock波函数,使用这一修正过的复光学势,在30—5000eV内对电子被4个等电子(Z=18)分子(HCl,H2S,PH3和SiH4)散射的总截面进行了计算,并将理论计算值与实验结果及其他理论值进行了比较.结果表明,利用这一修正过的复光学势及可加性规则进行计算,所得理论值与实验结果更为接近.
关键词:
电子散射
总截面
可加性规则
束缚原子 相似文献
85.
使用可加性规则,在Hartree-Fock水平上计算了30-3000eV的正电子被三个分子(O2、H2O及CH4)散射的总截面。计算正电子被三个分子散射的总截面时,首次使用了被束缚原子概念修正过的复光学势(这一复光学势考虑了分子中两个原子间的电子云重叠效应)。将正电子被这三个分子散射的总截面计算结果与实验结果及其它理论计算结果进行了比较,结果显示出在30-3000eV内,文中的计算结果与实验结果及其它理论计算结果具有较好的一致性。因此,可加性规则与修正后的复光学势相结合,完全适用于正电子被分子散射的总截面的计算。 相似文献
86.
Absolute Differential Cross Sections for Elastic Scattering of Electrons from CO at Intermediate and High Energies 下载免费PDF全文
The additivity rule model together with the complex optical model potential correlated by the concept of bonded atoms, which considers the overlapping effect of electron clouds between two atoms in a molecule, is firstly employed to calculate the absolute differential cross sections for electrons scattered by carbon monoxide at intermediate and high energies at the Hartree-Fock level. A comparison of elastic differential cross section results, obtained by using the correlated complex optical model potential, with the available experimental data,shows a significant improvement over the uncorrelated ones. The differential cross sections obtained by using thecorrelated complex optical model potential are in very good agreement with the experimental data. It is shown that the additivity rule model together with the correlated complex optical model potential is suitable for the calculations of the absolute differential cross sections of e-CO scattering. 相似文献
87.
利用可加性规则,使用Roothaan-Hartree-Fock波函数,在100~5 000 eV下首次采用由束缚原子概念修正过的复光学势,对电子被等电子(Z=10)分子CH4、H2O、HF和NH3散射的总截面进行了计算.束缚原子不同于自由原子之处,是束缚原子考虑了在不同分子中电子云的不同重叠,将计算结果与实验及其它计算结果进行了比较.结果表明,利用被束缚原子概念修正过的复光学势及可加性规则进行计算,其结果的精度要比利用未被束缚原子概念修正过的复光学势及可加性规则进行计算得到的结果好. 相似文献
88.
A modification potential method of calculating total cross sections of electrons scattering from complex molecules C2H6, C2F6, C6H6 and C6F6 at 100 eV-5000 eV 下载免费PDF全文
A complex optical model potential modified by
incorporating the concept of bonded atom, which takes into consideration the
overlapping effect of electron clouds between two atoms in a molecule, is
first employed to calculate the total cross sections for electrons
scattering from such complex molecules as C总交叉断面 电子散射 添加规则 原子分子碰撞 电子云 total cross section, electrons scattering, additivity
rule, atomic and molecular collision Project supported by the National Natural Science Foundation of China (Grant No 10574039). 2005-11-10 2005-11-102005-11-30 A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is first employed to calculate the total cross sections for electrons scattering from such complex molecules as C2H6, C2F6, C6H6 and C6F6 using the aclditivity rule model at Hartree-Fock level over the energy range from 100 eV to 5000 eV. The total cross sections are quantitatively compared with those obtained by experiments wherever available, and they are in good agreement with each other over a wide energy range. It is shown that the modified potential together with the additivity rule model is completely suitable for the calculation of total cross sections of electrons scattering from such complex molecules as C2H6, C2F6, C6H6 and C6F6 above 200 eV-300 eV. 相似文献
89.
Investigations of spectroscopic parameters and molecular constants for X1Σg+, w3Δu, and W1Δu electronic states of P2 molecule 下载免费PDF全文
The potential energy curves (PECs) of three low-lying electronic states (X1Σg+, w3Δu, and W1Δu)of P2 molecule are investigated using the full valence complete active space self-consistent field (CASSCF) method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach in conjunction with the correlation-consistent basis set in the valence range. The PECs of the electronic states involved are modified by the Davidson correction and extrapolated to the complete basis set (CBS) limit. With these PECs, the spectroscopic parameters of the three electronic states are determined and compared in detail with the experimental data. The comparison shows that excellent agreement exists between the present results and the available experimental data. The complete vibrational states are computed for the w3Δu, and W1Δu electronic states when the rotational quantum number J equals zero and the vibrational level G(v), the inertial rotation constant Bv, and the centrifugal distortion constant Dv of the first 30 vibrational states are reported, which accord well with the experimental data. The present results show that the two-point extrapolation scheme can obviously improve the quality of spectroscopic parameters and molecular constants. 相似文献
90.