大学物理课程思政教学思考与实践

该文针对非思政类课程的大学物理教学如何开展思政教育的问题,提出通过辩证唯物主义、社会主义核心价值观、科学素养及生态意识“四大着力点”挖掘大学物理课程思政元素,通过构建“线上线下融合一二三课堂的创新能力培养体系”,利用“学思做一体化”课程思政教学组织形式,将课程思政全面融入“一二三课堂”,达成“教学思政创新”多元协同的教学模式。

教师主导型研讨课的应用研究与实践——以“伯努利方程的应用”为例

大学物理教师往往被要求在有限的课时内完成繁重的教学任务,填鸭式教学因此成为大学物理教学一个明显的特征.这种传统教学模式的弊端已经十分突出,教学方法也亟待改变.研讨课的引入为当前课堂教学改革提供了一个切实可行的手段,它将为大学物理的教学从以教为主向以学为主转变、以课堂教学为主向课内外结合转变发挥积极的作用.

非傍轴高斯光束的传输特性

采用横截面上光强的精确表述,对非傍轴高斯光束的传输特性进行了理论分析。发现二阶矩定义下的光束束宽满足一般的双曲线传输规律。同时,数值计算表明,非傍轴高斯光束的传输因子与初始高斯宽度有关。在初始高斯半宽度小于0 123个波长时,光束传输因子小于1。

相位调制对双泵浦光参量放大器增益的影响

双泵浦波在光纤中的传输可以用耦合非线性薛定谔方程来描述,在群速度失配不能忽略和可以忽略两种情况下进行增益计算,并采用升余弦滚降信号作为相位调制信号,从理论上得到了双泵浦光参量放大器增益的解析解与数值解,并由此得到增益曲线。得到采用不同波长的泵浦波,也就是在群速度失配的情况下,增益要比群速度匹配的情况下大些,采用不同波长的泵浦波有利于提高光参量放大器的增益。且在相位调制的上升和下降时间段,增益有起伏的特点。

双酚A在氧化石墨烯表面吸附的分子动力学模拟

双酚A(bisphenol A,BPA)是一种内分泌干扰物,会对机体多方面产生不良影响,包括生殖系统、神经系统、胚胎发育等.因此,在水环境中如何检测和去除BPA显得尤为重要.实验研究表明,氧化石墨烯(graphene oxide,GO)对BPA具有优异的吸附去除性能,但在分子层面的吸附机制尚不清楚.分子动力学模拟,能提供BPA在GO表面的动态吸附过程以及吸附构象等详细信息,可以弥补实验的不足.本文利用GROMACS分子动力学模拟软件,系统模拟了BPA在含GO的水溶液中的吸附过程,并计算了吸附自由能.结果显示:所有的BPA均被吸附在GO两侧,通过分析BPA的吸附构象以及与GO的相互作用,发现π-π疏水作用对吸附起主导作用,且显示出很好的稳定性,而静电和氢键作用增加了GO的吸附能力.通过自由能计算,BPA在GO表面的结合能达30 k J/mol,远大于水分子的5 k J/mol.这些结果进一步证实GO对BPA具有很强的吸附能力以及GO作为吸附剂在水溶液中去除BPA的可行性.

不同尺度的蛋白质在纯石墨烯及氧化石墨烯表面的吸附比较（英文）

本文运用分子动力学模拟的方法，系统地比较了不同大小的蛋白质在石墨烯及其氧化物表面的吸附稳定性和构象变化．结果表明在含氧官能团的静电作用的协助下，GO的吸附稳定性要强于PG；由少量残基组成的多肽在PG和GO表面其α螺旋结构部发生变化，蛋白片段在PG表面部分α螺旋被破坏，在GO表面保持完好，而完整的球状蛋白在PG和GO表面结构都没发生明显变化，尤其是GO，体现出良好的生物相容性．GO作为吸附底物在纳米生物技术领域显示出良好的应用前景．

Chirped Domain Wall Arrays and Solitary Waves in a Generalized Nonlinear Schrodinger Equation

We study a generalized nonlinear Schrdinger equation,and obtain some exact solutions,including domain wall arrays (periodic solutions in terms of elliptic functions),fronts,bright and dark solitons.In certain parameter domains,fundamental bright and dark solitons show directionality and hence are chiral,and the propagation direction is determined by the sign of the self-steepening parameter.Moreover,the chirping reversal phenomena of bright and dark solitons are found.

Exact periodic solution in coupled nonlinear Schodinger equations

The coupled nonlinear Schodinger equations （CNLSEs） of two symmetrical optical fibres are nonintegrable, however the transformed CNLSEs have integrability. Integrability of the transformed CNLSEs is proved by the Hamilton dynamics theory and Galilei transform. Making use of a transform for CNLSEs and using the ansatz with Jacobi elliptic function form, this paper obtains the exact optical pulse solutions.

Molecular dynamics simulations of the effects of sodium dodecyl sulfate on lipid bilayer

Molecular dynamics simulations have been performed on the fully hydrated lipid bilayer with different concentrations of sodium dodecyl sulfate （SDS）. SDS can readily penetrate into the membrane. The insertion of SDS causes a decrease in the bilayer area and increases in the bilayer thickness and lipid tail order, when the fraction of SDS is less than 28%. Through calculating the binding energy, we confirm that the presence of SDS strengthens the interactions among the DPPC lipids, while SDS molecules act as intermedia. Both the strong hydrophilic interactions between sulfate and phosphocholine groups and the hydrophobic interactions between SDS and DPPC hydrocarbon chains contribute to the tight packing and ordered alignment of the lipids. These results are in good agreement with the experimental observations and provide atomic level information that complements the experiments.

Manipulating the Flipping of Water Dipoles in Carbon Nanotubes

Flipping of water dipoles in carbon nanotubes is of great importance in many physical and biological applications,such as signal amplification,molecular switches and nano-gates.Ahead of these applications,understanding and inhibiting the non-negligible thermal noise is essential.Here,we use molecular dynamics simulations to show that the flipping frequency of water dipoles increases with the rising temperature,and the thermal noise can be suppressed by imposed charges and external uniform electric fields.Furthermore,the water dipoles flip periodically between two equiprobable and stable states under alternating electric fields.These two stable states may be adopted to store 0 and 1 bits for memory storage or molecular computing.

Ultrashort optical solitons in the dispersion-decreasing fibers

We derive analytical bright and dark solitons of the modified nonlinear Schroedinger equations with variable coefficients. Under constraint conditions between system parameters, the optical soliton transmission in the dispersiondecreasing fibers can be exactly controlled by proper dispersion management. The analytical description of the interactions between the bright and dark solitons are first obtained.

周期色散管理波分复用系统中交叉相位调制边带不稳定性理论分析

色散管理是在波分复用系统中,周期地使用色散符号相反的光纤,使总的路径平均色散系数接近于零,系统中的色散就得到了补偿的一种技术.研究了波分复用集总放大色散管理系统中交叉相位调制的不稳定性,解析和数值研究表明,当路经平均色散系数表现为反常色散时,存在多阶边带;当路经平均色散系数表现为正常色散时,解析研究表明只存在最低阶边带,数值模拟显示噪声谱中最低阶边带噪声谱功率最强,解析和数值研究得到的结论一致.