First-principles calculations for transition phase and thermodynamic properties of GaAs

The transition phase of GaAs from the zincblende (ZB) structure to the rocksalt (RS) structure is investigated by ab initio plane-wave pseudopotential density functional theory method, and the thermodynamic properties of the ZB and RS structures are obtained through the quasi-harmonic Debye model. It is found that the transition from the ZB structure to the RS structure occurs at the pressure of about 16.3\,GPa, this fact is well consistent with the experimental data and other theoretical results. The dependences of the relative volume V/V₀ on the pressure P, the Debye temperature \Th and specific heat C_V on the pressure P, as well as the specific heat C_V on the temperature T are also obtained successfully.     

First-principles calculations of structure and high pressure phase transition in gallium nitride

The phase transitions of semiconductor GaN from the Wurtzite (WZ) structure and the zinc-blende (ZB) structure to the rocksalt (RS) structure are investigated by using the first-principles plane-wave pseudopotential density functional method combined with the ultrasoft pseudopotential scheme in the generalized gradient approximation (GGA) correction. It is found that the phase transitions from the WZ structure and the ZB structure to the RS structure occur at pressures of 46.1 GPa and 45.2 GPa, respectively. The lattice parameters, bulk moduli and their pressure derivatives of these structures of GaN are also calculated. Our results are consistent with available experimental and other theoretical results. The dependence of the normalized formula-unit volume $V/V_{0 }$ on pressure $P$ is also successfully obtained.     

利用迈克耳孙干涉仪测量蔗糖溶液的质量分数

利用迈克耳孙干涉仪测量蔗糖溶液的质量分数,在光路中加入装有蔗糖溶液的玻璃杯,逐渐向玻璃杯中加入蔗糖,改变蔗糖的质量分数,进而改变蔗糖的折射率,通过记录相应干涉条纹的变化,计算出新溶液的质量分数.     

迈克耳孙干涉仪圆心位置微调系统的设计

迈克耳孙干涉实验中干涉图像的圆心不易调节并且容易损坏仪器,为此设计了限位拉杆调节螺钉装置与磁力调心装置,改良后的实验装置可以使操作者快速、准确地调节好干涉图像的圆心位置。     

光敏电阻延时特性的验证及光强对其影响的探究

验证了光敏电阻的延时特性,并研究了光强对光敏电阻响应时间的影响.实验表明,光敏电阻存在延时特性,光强改变前的光照强度以及光强改变量都会影响光敏电阻的响应时间.光强初始值越大,响应时间越短;光强改变量越大,响应时间越短.     

“厚基础、宽口径、分层次、求创新、拔尖型”人才培养方案的研究

针对传统大学物理实验教学体系存在的问题,重建大学物理实验教学体系。构建"厚基础、宽口径、分层次、求创新、拔尖型"的人才培养方案。建立自主、合作、研究式的教学模式,激发学生的学习兴趣,培养学生的创新与动手能力。