基于BOPPPS混合教学模式的分析力学精品课程建设探讨

随着现代教育技术的迅猛发展,线上线下混合教学模式和BOPPPS教学模式都日趋成熟,并且在实际教学过程中取得了显著的成效。文章提出基于BOPPPS教学模式和混合教学模式相结合的分析力学精品课程建设,旨在降低课程学习难度,激发学生学习兴趣和加强学生对分析力学知识体系的深刻理解和实际应用,为高质量课程教学的实现提供了新的思路。

探索和实践:量子力学与固体物理课程群的建设

随着科技的进步,量子力学和固体物理对于物理、材料科学和工程技术等多个领域产生了深远影响,对量子力学和固体物理的理解变得越来越重要。然而,现有的课程设置往往将量子力学和固体物理作为独立的学科来教授,缺乏对二者之间联系的综合性教育。本文提出了一种课程群的建设方案,并总结了课程群的优势和潜在挑战。通过建设量子力学和固体物理课程群,学生将能够更好地理解和应用这两个领域的知识,为未来的科学研究和技术创新做出贡献。

新工科背景下高等量子力学的课程建设

随着新工科教育理念的兴起和量子技术的迅猛发展,高等量子力学的课程建设也面临着新的挑战和机遇。在新工科背景下,如何有效地进行高等量子力学课程的建设是满足学生对于量子力学知识与技能需求的重要环节。文章基于传统高等量子力学课程的问题分析,并提出高等量子力学课程建设的关键要素以及可以采用的教学方法,并对高等量子力学课程建设的未来发展提出了一些值得探索的实践方向。

稀土元素铈对钢中非金属夹杂物改性和腐蚀影响的第一性原理研究

通过原位腐蚀观察和基于密度泛函理论的第一性原理计算方法,从微观角度研究了稀土元素铈(Ce)对J5不锈钢中夹杂物的改性和夹杂物诱导腐蚀的机理.采用扫描电子显微镜与能谱分析了稀土元素Ce改性夹杂物的过程中夹杂物成分和类型的变化,观察到的代表夹杂物为Ce Al O_(3)-Ce_(2)O_(2)S、Ce_(2)O_(3)-Ce_(2)O_(2)S、Mn S等.根据形成能计算,经稀土元素Ce处理后,生成了稳定的Ce_(2)O_(3)、Ce_(2)O_(2)S、Ce Al O_(3)夹杂物.通过表面能判断了晶面的稳定性,Fe(100)-2面的表面能经收敛测得为2.4374 J·m^(-2),该晶面的功函数为4.7352 e V.通过对比夹杂物与钢基体的功函数与计算电势差,分析了不同含Ce夹杂物诱导点蚀的趋势,探讨了不同原子位置、原子数量和不同slab模型对功函数的影响.研究表明,与Fe(100)-2面的电子功函数相比,Mn S以及改性后3种夹杂物Ce S、Ce_(2)O_(3)和Ce_(2)O_(2)S电势差大多小于0,Ce Al O_(3)的电势差在0 e V左右.夹杂物不同晶面对功函数影响很大,O、S等非金属原子数量多的晶面功函数平均值较高,添加稀土元素Ce可以有效降低晶面功函数.5种夹杂物和钢基体的平均功函数大小顺序为Ce Al O_(3)>Fe>Mn S>Ce S>Ce_(2)O_(2)S>Ce_(2)O_(3).结合不锈钢中复合夹杂物的实验结果可知,Ce_(2)O_(3)诱导点蚀发生的概率最高,Ce Al O_(3)可以有效提高钢的耐腐蚀能.

Effects of layer stacking and strain on electronic transport in two-dimensional tin monoxide

Tin monoxide(SnO) is an interesting two-dimensional material because it is a rare oxide semiconductor with bipolar conductivity.However, the lower room temperature mobility limits the applications of SnO in the future.Thus, we systematically investigate the effects of different layer structures and strains on the electron–phonon coupling and phonon-limited mobility of SnO.The A2uphonon mode in the high-frequency region is the main contributor to the coupling with electrons for different layer structures.Moreover, the orbital hybridization of Sn atoms existing only in the bilayer structure changes the conduction band edge and conspicuously decreases the electron–phonon coupling, and thus the electronic transport performance of the bilayer is superior to that of other layers.In addition, the compressive strain of ε=-1.0% in the monolayer structure results in a conduction band minimum(CBM) consisting of two valleys at the Γ point and along the M–Γ line, and also leads to the intervalley electronic scattering assisted by the Eg(-1)mode.However, the electron–phonon coupling regionally transferring from high frequency A2uto low frequency Eg(-1)results in little change of mobility.

Electronic and magnetic properties of single-layer and double-layer VX_(2)(X=Cl,Br)under biaxial stress

First-principles calculations and Monte Carlo simulations reveal that single-layer and double-layer VX_(2)(X=Cl,Br)can be tuned from antiferromagnetic(AFM)semiconductors to ferromagnetic(FM)state when biaxial tensile stress is applied.Their ground states are all T phase.The biaxial tensile stress at the phase transition point of the double-layer VX_(2) is larger than that of the single-layer VX_(2).The direct band gaps can be also manipulated by biaxial tensile stress as they increases with increasing tensile stress to a critical point and then decreases.The Neel temperature(´TN)of double-layer VX_(2) are higher than that of single-layer.As the stress increases,the TN of all materials tend to increase.The magnetic moment increases with the increase of biaxial tensile stress,and which become insensitive to stress after the phase transition points.Our research provides a method to control the electronic and magnetic properties of VX_(2) by stress,and the single-layer and double-layer VX_(2) may have potential applications in nano spintronic devices.

Novel Boron Nitride Polymorphs with Graphite-Diamond Hybrid Structure

Both boron nitride(BN)and carbon(C)have sp,sp^(2)and sp^(3)hybridization modes,thus resulting in a variety of BN and C polymorphs with similar structures,such as hexagonal BN(hBN)and graphite,cubic BN(cBN)and diamond.Here,five types of BN polymorph structures are proposed theoretically,inspired by the graphite-diamond hybrid structures discovered in a recent experiment.These BN polymorphs with graphite-diamond hybrid structures possess excellent mechanical properties with combined high hardness and high ductility,and also exhibit various electronic properties such as semi-conductivity,semi-metallicity,and even one-and two-dimensional conductivity,differing from known insulators hBN and cBN.The simulated diffraction patterns of these BN hybrid structures could account for the unsolved diffraction patterns of intermediate products composed of so-called“compressed hBN”and diamond-like BN,caused by phase transitions in previous experiments.Thus,this work provides a theoretical basis for the presence of these types of hybrid materials during phase transitions between graphite-like and diamond-like BN polymorphs.

应变对量子材料新奇物性的调控

新型量子材料具有丰富的新奇物性,是现代凝聚态物理和材料科学研究的重要主题之一.常见的物性调控手段有很多,比如应变场、外电场、磁场、光场以及化学吸附等.其中,应变作为调节材料物性的有效手段被广泛地应用于研究中.本文对近年来发现的多种新型量子材料(拓扑材料和二维材料)进行介绍,并重点阐述本课题组在这些材料中应变效应的相关研究进展.在拓扑材料方面,主要介绍拓扑绝缘体、拓扑狄拉克半金属以及拓扑节线半金属中应变导致的拓扑相变等;在单层二硫化钼和黑磷中,对应变调节载流子输运和超导电性等研究结果进行讨论;最后对二维铁磁、铁电材料方面应变调节磁矩、电极化、居里温度以及磁光效应等问题进行了相关分析.