“光谱”教学中的几个问题

中学物理中“光谱及光谱分析”这部分内容 ,虽然篇幅不多 ,但其内容丰富 ,学生在学习中常会提出许多问题 .这里选择若干典型问题 ,作一定性解释 ,希望有助于学生理解这些内容 .1　为什么稀薄气体或金属蒸汽发射明线光谱 ?根据量子理论 ,原子有一系列分立的能级 ,原子能级中能量最低的称为基态 ,其余的称为激发态 .原子因吸收外界能量会从基态或低能态跃迁到高能态 ,该过程称为原子的激发 .处于激发态的原子若由较高的激发态跃迁到较低的激发态或基态时就会发出一定频率的色光 ,其频率由Ｅ2 -Ｅ1=ｈν决定 .由于原子能级不连续 ,因此 ,发出的…     

能级跃迁中氢原子谱线条数的分析方法

在原子中,当原子吸收外界能量后处于激发态,而激发态的原子是不稳定的,当它向较低能级跃迁时就会释放能量、而能量是以光子（电磁波）形式向外辐射,     

∧型三能级原子在圆极化光场中的自发衰变

∧型三能级原子与圆极化光相互作用时,圆极化光将对原子寿命及原子的自发衰变规律产生影响．∧型三能级原子最初处于激发态,圆极化光将改变原子的寿命,并且在几率表达式中出现振荡项．     

∧型三能级原子在圆极化光场中的自发衰变

∧型三能级原子与圆极化光相互作用时,圆极化光将对原子寿命及原子的自发衰变规律产生影响。∧型三能级原子最初处于激发态,圆极化光将改变原子的寿命,并且在几率表达式中出现振荡项。     

N个原子系统中的自发发射

本文研究多模辐射场与N个两能级原子的相互作用。当初始状态为一个原子处于激发态其余原子都处于基态时，得到了自发发射过程中系统的动力学规律。并将计算结果与其他一些已知的理论结果进行比较。     

N个原子系统中的自发发射

本文研究多模辐射场与N个两能级原子的相互作用．当初始状态为一个原子处于激发态、其余原子都处于基态时，得到了自发发射过程中系统的动力学规律．并将计算结果与一些已知的理论结果进行比较．     

原子电离的几个纠结问题

对于原子电离的相关问题,人教版高中《物理》选修3-5中讲到:如果处于基态的氢原子获得大于13.6eV的能量,其核外电子将跃迁到无穷远处即发生电离,13.6eV就是氢原子的电离能.这部分介绍粗浅模糊,致使教师与学生在教学或学习过程中常会遇到一些非常纠结的问题,有必要进行深入探讨.一、处于激发态的原子能够被电离吗题目1用3.7eV能量的光子照射处于n=2激发态的氢原子时,则()     

N个原子系统中的自发发射

本文研究多模辐射场与Ｎ个两能级原子的相互作用。当初始状态为一个原子处于激发态、其余原子都处于基态时，得到了自发发射过程中系统的动力学规律。并将计算结果与一些已知的理论结果进行比较。     

原子跃迁中应注意的几个问题

一、分清发生跃迁的是一个原子还是一群原子例1 有一个氢原子处于量子数为n=3的激发态,则该氢原子最多能辐射几条谱线.其中频率最低的光的波长为多少米.在图1中标出.     

耦合腔内原子的量子纠缠与量子关联

考虑耦合腔内两原子的量子纠缠和量子关联随时间的演化。数值模拟结果表明,对于最大纠缠态,随着腔与腔耦合强度的增加,两原子的量子关联和纠缠都得到维持。此外,当两原子初始都处于激发态时,则原子之间产生非纠缠的量子关联。     

奇偶指数与链烷烃原子化热的关系

在距离矩阵的基础上提出一种新的拓扑指数一奇偶指数OE,该指数对C1-C10的150个链烷烃有很好的结构区分性。将其对C1-C9的有关链烷烃的原子化热进行结构性质相关,结果表明,该指数具有良好的性质相关性。奇偶指数计算简便,有望作为一个重要参数在QSPR／QSAR研究中得到应用。     

激光场与原子相互作用

本文用量子理论研究激光场与三个原子的相互作用。当初始条件为激光场中有N个光子,而三个原子都处于高能级时,得到了光子数和原子状态各自随时间的变化关系。光子数很大时,量子理论结果与半经典理论结果是一致的。     

金属表面单原子操纵研究进展

扫描隧道显微镜或原子力显微镜使人们能够操纵吸附在材料表面的单个原子或分子．这种技术可从单个原子、分子开始组装具有特定功能的纳米结构,也能组装、拆解分子从而控制化学反应的进程,将在物理、化学等多学科领域发挥重要作用．本文综述了近年来在金属材料表面进行单原子操纵的研究进展,介绍了单原子操纵的方法和机制,并对有待进一步研究的若干问题进行初步探讨．     

Mg6B14笼状团簇的密度泛函理论研究

从第一性原理出发,采用密度泛函理论（DFF）的杂化密度泛函B3LYP方法,在6—31G（d）全电子基组水平上对Mg6B14笼状结构团簇进行了结构优化和频率分析,同时对团簇的能隙、结合能等电子性质进行了分析,用自然键轨道（NaturalBondOrbital,NBO）方法分析了团簇的电荷布局特性和成键性质。结果表明,电荷从Mg原子上转移到B原子上,主要是位于环上的B原子之间成键。B原子主要是sp杂化形成的π键、大π键,Mg原子主要是S轨道参与成键。     

Electronic structure and magnetism of RMn6 Sn6 (R=Tb,Dy)

This article reports first-principles band structure calculations for RMn6Sn6 (R=Tb, Dy). The calculation uses the linear muffin-tin orbitals (LMTO) method in the atomic-sphere-approximation (ASA), and yields results showing that both TbMn6Sn6 and DyMn6Sn6 are ferrimagnetic compounds with antiparallel aligned moments of R and Mn atoms. In this research the 4f states of R atoms are treated as localized states, i.e., the hybridization of 4f states with other valence electrons is neglected. The moments of Mn in both compounds were determined to be 2.43 μB and 2.38 μB, respectively. The considerably small additional moments for Mn from the spin-orbit coupling indicates that the spin-orbital coupling is not dominated for Mn atoms. The total moments of Tb and Dy atoms are 10.28 μB and 11.20 μB. All the calculation findings accorded well with experimental results.     

Bohrium — A new element in the periodic table

Conclusions As can be seen from the above, due to the marginally higher half-life of Bh, some experiments could be carried out to find out about the chemical nature of the element. Since the elements are produced in extremely small quantities (a few atoms in many cases), it is difficult to confirm the stability of most of these elements. If the half-lives are as long as predicted (region of stability), and there are sufficient yields, there are exciting possibilities for chemical studies of the super-heavy elements. It is likely that the heavy elements may also have multiple oxidation states. In this context, 10–100 atoms of the super-heavy species are needed depending on the half-life. If, on the other hand, we are limited to a few atoms of these super-heavy species, it is likely that any further use of them would be very restricted. However, the Holy Grail of super-heavy elements has been one in which one began by creating a handful of atoms and perhaps, one day we may learn to produce them in sufficient quantity for real chemical investigations.     

激光场与三个两能级原子相互作用的全量子理论分析

本文用全量子理论研究激光场与三个原子的相互作用。在不同的初始条件下,得到了光子数和原子状态各自随时间的变化关系。光子数很大时,全量子理论结果与半经典理论结果是一致的。     

A cross-age study of the understanding of five chemistry concepts

A sample of 100 students from junior high school physical science, high school chemistry, and introductory college chemistry were examined for understanding of five chemistry concepts. The concepts addressed were chemical change, dissolution of a solid in water, conservation of atoms, periodicity, and phase change. The amount of experience with the concepts (grade level) and reasoning ability (developmental level) were examined as possible sources of variation in student understanding. Differences in understanding with respect to grade level were found to be significant for the concepts of chemical change, dissolution of a solid, conservation of atoms, and periodicity. However, few of the students in the college chemistry sample exhibited sound understanding of chemical change, periodicity, or phase change. The use of particulate terms (atoms, ions, molecules) increased across the grade levels. Reasoning ability proved to be a significant factor for student understanding of conservation of atoms and periodicity. An examination of the number and types of misconceptions across the grade levels revealed several interesting patterns and suggested sources for the students' alternative conceptions.     

两能级原子与辐射的相互作用

本文研究两个两能级原子与辐射的相互作用。在不同的初始条件下,得到了原子处于高能态的几率以及辐射场中的光子数随时间的变化规律。     

R/S构型的平面确定法

对于一个旋光异构体的费什尔投影式中任一手性碳原子来说,若最小的原子在水平线或在垂线上,只要看其三个原子或基团在水平面上的走向,即可判断出其构型.