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我们知道,函数y=f(x)若存在反函数,则y=f(x)与它的反函数y=f~(-1)(x)有如下性质:若y=f~(-1)(x)是函数y=f(x)的反函数,则有f(a)=b(?)f~(-1)(b)=a.这一性质的几何解释是y=f(x)与其反函数y=f~(-1)(x)的图像关于直线y=x对称.也就是说若原函数过点(a,b),则其反函数必过点(b,a).反函数中这个重要的小结论,别看它貌 相似文献
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电子被HF和HCl分子散射总截面的计算 总被引:1,自引:1,他引:0
利用光学势方法计算了能量在10eV—1000eV范围内电子被H、F和Cl原子散射的总截面,并与已有的实验结果和理论计算进行了比较;又利用可加性规则(additivityrule)计算得到了电子被HF和HCl分子散射的总截面,计算结果也与已有的实验结果和理论计算进行了比较 相似文献
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Ab initio calculations on the spectroscopic constants, vibrational levels and classical turning points for the 21∏u state of dimer 7Li2 下载免费PDF全文
The accurate dissociation energy and harmonic frequency for the highly excited 2^1Пu state of dimer ^7Li2 have been calculated using a symmetry-adapted-cluster configuration-interaction method in complete active space. The calculated results are in excellent agreement with experimental measurements. The potential energy curves at numerous basis sets for this state are obtained over a wide internuclear separation range from about 2.4a0 to 37.0a0. And the conclusion is gained that the basis set 6-311++G(d,p) is a most suitable one. The calculated spectroscopic constants De, Re, ωe, ωeχe, ae and Be at 6-311++G(d,p) are 0.9670 eV, 0.3125 nm, 238.6 cm^-1, 1.3705 cm^-1, 0.0039 cm^-1 and 0.4921 cm^-1, respectively. The vibrational levels are calculated by solving the radial SchrSdinger equation of nuclear motion. A total of 53 vibrational levels are found and reported for the first time. The classical turning points have been computed. Comparing with the measurements, in which only the first nine vibrational levels have been obtained so far, the present calculations are very encouraging. A careful comparison of the present results of the parameters De and We with those obtained from previous theories clearly shows that the present calculations are much closer to the measurements than previous theoretical results, thus representing an improvement on the accuracy of the ab initio calculations of the potentials for this state. 相似文献
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使用SAC/SAGCI方法,利用6-311G,6.311++G,6-311G(3df,3pd),D95V(d,p),D95,D95V,6-311++C(3af,3Pd),D95(3df,3t,d)、cc-PVTZ和AUG-cc-PVTZ等基组.对Li2分子的B1Ⅱu及X1∑+8态的平衡几何进行了优化计算.同时,在优化得到的平衡位置附近、于同一条件下通过精细的单点能扫描,也获得了相应基组下的平衡核间距.发现优化计算结果与精细的单点能扫描结果不一致.分析表明由单点能扫描获得的平衡核间距应更为合理.通过对平衡按间距及计算离解能的比较,得出了对B1ⅡU态而言AUG-OC-P扩12基组为最优基组的结论.在AUG-cc-PyIZ基组下,于0.135~l.5 nm范围內,利用SAC的GSUM(Group Sum of Operators)方法对X1∑+8态、SAC-CI的GSUM方法对月B1Ⅱu态进行单点能扫描、井用正規方程组拟合出了相应的解析势能函数.利用解析势能函数的物理意义并结合RKR方法,计算出了X1∑+8态及B1Ⅱu态的谐振频率,理论计算结果与实验值较为一致. 相似文献
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The structure of the Si3Ox (x=2, 3) cluster is investigated; we find that the geometry of Si3O2 is similar to that of Si3O3 except for the oxygen-deficient defect structure (Si-Si band) which exists only in the Si3O2 cluster. It is known that oxygen-deficient defects are used to explain visible luminescence (especially blue, purple and ultraviolet light) from silicon-based materials, which are directly bound up with the excited states of the molecules. Therefore the excitation properties of the two clusters are also studied. Our results show that the absorption spectrum of Si3O2 is concentrated in the visible light region. In contrast, the absorption spectrum of Si3O3 is mainly located in the ultraviolet light region. The calculations are perfectly consistent with experimental data and also support the theory of oxygen-deficient defects. 相似文献
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利用可加性规则,使用HartreeFock波函数,采用由束缚原子概念修正过的复光学势(由静 电势、交换势、修正极化势及吸收势这四部分组成),在较大的能量(30—5000eV)范围内对 电子被甲烷及氯代甲烷(CH4,CCl4,CHCl3,CH2Cl2和CH 3Cl)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 果的精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电子被分子散射的总截面的计算准确度.
关键词:
电子散射
可加性规则
束缚原子
总截面 相似文献
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这是一种利用量子场论所进行的探究性的研究方法,在文章中,我们设 计了一种新的较为简单的电子-原子碰撞模型,将量子场论方法与光学势方法中的可加性规 则结合起来.利用这种模型,我们计算了e-H,e-He和e-Li的微分碰撞截面,获得了较满意的 结果. 相似文献