化学势依赖于系统内的所有物质

在热力学中，关于多元系的化学势的变量集，有互不一致的两种结论.一种结论认为，某种物质的化学势，仅仅依赖于其它物质的存在，另外一种认为，不仅依赖于其它物质，也依赖于自己.本文通过详细的分析论证了，一般而言，化学势依赖于系统内的所有物质.     

电极电势:从电化学势说起*

对于原电池,电极电势的本质是化学体系对电极材料上电子势能的影响,其正负极电势差反映化学能向电能转化的趋势。电极界面上化学物质的氧化/还原反应是通过何种途径影响到电极上电子势能的,现有的教材和论著没有给出明确的解释。本文基于相间电化学势平衡原则阐明了固液界面上离子平衡与电极上电子电势的关系,并由此给出了标准电势的物理含义:它是构成电极体系一系列物性参数的组合,包括被测电极的电子、离子化学势,工作电极电解液的离子化学势,参比电极的电子、离子化学势和参比电极电解液的离子化学势等。     

Realization of Spin Switch in a Triple-Terminal Double-Quantum-Dot Structure

Electron transport through a triple-terminal double-quantum-dot structure is theoretically studied. By adjusting the chemical potential in leads, two channels in this system are created, and in the presence of magnetic flux the conductances for the two channels present remarkable difference from each other. When the quantum dots are made of ferromagnetic materials, the levels of quantum dots are spin dependent, then spin polarization comes about in the two channels. Furthermore, in some regions spin polarization in the different channels are opposite. We consider that this model can be a device prototype for spin filtering and spin separation.     

含石墨烯二维金属结构中的自发辐射研究

研究原子在金属结构中的自发辐射时引入单层石墨烯薄膜,利用石墨烯特殊的光电特性来调控原子的自发辐射率.推导了局态密度与自发辐射率的格林函数表示形式,并结合频域有限差分方法进行了数值模拟.分析结果表明:随着化学势的增大,自发辐射波峰出现蓝移现象,且自发辐射率波峰得到增强,理论上实现了原子自发辐射率峰值位置与幅度的调制.研究结果可以为新型纳米器件及光电子设备的制造和优化提供参考.     

Sandwich教学法在物理化学教学中的应用——以化学势表达式的推导为例

以化学势表达式的推导为例,探究了Sandwich教学法在物理化学教学中的应用。详细介绍了Sandwich教学法实施过程中教师如何提出问题以呈现教学目标,学生如何通过自主学习与全班交流来探究与解决问题,以及最后又如何通过总结与反馈回归教学目标。通过以学生为主体的Sandwich教学过程的实施,学生对化学势概念、热力学基本方程及状态函数法等重要的物理化学基本概念、公式及方法有了更深入的理解和掌握。Sandwich教学方法相较于传统教学模式更能激发学生学习的主动性和积极性,从而提高学生学习物理化学的兴趣与效果。     

Linear Chemical Potential Dependence of Two-Quark Condensate

By differentiating the inverse dressed quark propagator at finite chemical potential μ with respect to μ, the linear response of the dressed quark propagato r to the chemical potential can be obtained, From this we extract a modelindependent formula for the linear chemical potential dependence of the in-medium two-quark condensate and show by two independent methods （explicit calculation and Lorentz covariance arguments） that the first-order contribution in μ to the in-medium two-quark condensate vanishes identically. Therefore if one wants to study the in-medium two-quark condensate one should expand to at/east the second order in the chemical potential μ.     

双外场对费米气体Joule-Thomson效应的调控简

研究匀强电场和谐振场构成的双外场对带电费米粒子系统化学势和Joule-Thomson系数的调控作用.在满足Thomas-Fermi近似的条件下,给出有限温度范围内匀强电场和谐振场中带电费米粒子系统的化学势和内能随温度变化的显式函数关系,分析双外场对带电费米粒子系统焦耳-汤姆逊系数的调控作用.研究结果表明,随着温度的升高,带电费米粒子系统的焦汤系数值逐渐由负变正,且临界温度Tc随外电场增强而降低.在适当温度下,外势场的存在会使带电费米粒子系统产生焦耳-汤姆逊正效应.     

Bulk viscosity of hot dense Quark matter in the PNJL model

Starting from the Kubo formula and the QCD low energy theorem, we study the the bulk viscosity of hot dense quark matter in the PNJL model from the equation of state. We show that the bulk viscosity has a sharp peak near the chiral phase transition, and that the ratio of bulk viscosity over entropy rises dramatically in the vicinity of the phase transition. These results agree with those from the lattice and other model calculations. In addition, we show that the increase of chemical potential raises the bulk viscosity.     

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用高密度等离子体模型可以计算出一整套输运参数,并且在很宽的等离子体温度和密度范围内有合理的精度,可广泛应用于Z箍缩等离子体、激光聚变和磁约束聚变等领域,并将这个模型计算出的各种输运参数拟合成了实用的公式。     

Why Do Deconfinement and Chiral Restoration Coincide at High Temperature？

The global colour model in free space is extended to finite temperature to study the deconfinement and chlral phase transitions at high temperature T and zero chemical potential in the mean field approximation. Both possibilities of coincidence and non-coincidence of the two distinct phase transitions are found when the model