大学物理实验课程思政教学实践与探索

习近平总书记在全国高校思想政治工作会议发表重要讲话中强调“要坚持把立德树人作为中心环节,把思想政治工作贯穿教育教学全过程,实现全程育人、全方位育人”,要让“各类课程与思想政治理论课程同向同行,形成协同效应”.作为受益学生面较大的公共基础课程,大学物理实验在思想政治教育融入研究和实践方面具有独特优势.从大学物理实验课程思政教学问题出发,分析开展“同向同行”思政教育的可行性设计,并以具体教学实践探讨思政元素的有机融入路径和方法.     

水杨酸分子印迹分离介质的水相制备及色谱行为

以水杨酸为模板分子,2-乙烯基吡啶为功能单体,在甲醇/水体系中制备了水杨酸分子印迹聚合物,并将其作为高效液色谱分离介质研究了其对水杨酸及水杨酸的位置异物体———对羟基苯甲酸的色谱行为。结果表明,该聚合物固定相表现出良好的分离选择性,能够使水杨酸与对羟基苯甲酸快速基线分离。通过对流动相组成与色谱分离效果关系的探讨,证实溶质与印迹固定相的疏水相互作用是分子识别的主要作用力。     

以学生为中心的立体化物理实验课程教学改革探索

在教育教学活动实现信息化的过程中,各类课程逐渐呈现出立体化的发展趋势.通过课程内容的创新重构、教学活动的时间与空间立体化,以及全过程评价的多元化改造等手段实现课程的立体化,并充分体现学生作为学习过程中主导者的中心地位,已成为当前各类课程教学改革的重要目标.以物理实验课程为例,通过对课程目前存在问题成因的深入分析,提出了...     

High Power Er/Yb Codoped Double Clad Fiber Pulsed Amplifier Based on an All-Fiber Configuration

We report an all-fiber two-stage high power pulsed amplifier, seeded with a 1550nm, 1 kHz repetition rate rectangular pulse, and based on Er/Yb co-doped double clad fiber. All the characteristics are measured in the experiment. The maximal slope efficiency is 22.56%, which is the highest we know of at such a low repetition rate, and the maximal output signal power is 1W. The various factors that affect the pulsed amplifier performance are analyzed. A high output power while keeping high power conversion efficiency can be obtained with careful selection of the input power, pump power and repetition rate. The experimental results show that the crucial parameters should be optimized when designing all-fiber pulsed amplifiers.     

First-principles analysis of the structural,electronic, and elastic properties of cubic organic-inorganic perovskite HC(NH_2)_2PbI_3

The structural, electronic, and elastic properties of cubic HC(NH_2)_2PbI_3 perovskite are investigated by density functional theory using the Tkatchenko–Scheffler pairwise dispersion scheme. Our relaxed lattice parameters are in agreement with experimental data. The hydrogen bonding between NH_2 and I ions is found to have a crucial role in FAPbI_3 stability. The first calculated band structure shows that HC(NH_2)_2PbI_3 has a direct bandgap(1.02 eV) at R-point, lower than the bandgap(1.53 eV) of CH_3NH_3PbI_3. The calculated density of states reveals that the strong hybridization of s(Pb)–p(I) orbital in valence band maximum plays an important role in the structural stability. The photo-generated effective electron mass and hole mass at R-point along the R–Γ and R–M directions are estimated to be smaller: m_e~*= 0.06 m0 and m_h~*= 0.08 m0 respectively, which are consistent with the values experimentally observed from long range photocarrier transport. The elastic properties are also investigated for the first time, which shows that HC(NH_2)_2PbI_3 is mechanically stable and ductile and has weaker strength of the average chemical bond. This work sheds light on the understanding of applications of HC(NH_2)_2PbI_3 as the perovskite in a planar-heterojunction solar cell light absorber fabricated on flexible polymer substrates.     

Structural,elastic, electronic,and thermodynamic properties of MgAgSb investigated by density functional theory

The structural, elastic, electronic, and thermodynamic properties of thermoelectric material Mg Ag Sb in γ, β, α phases are studied with first-principles calculations based on density functional theory. The optimized lattice constants accord well with the experimental data. According to the calculated total energy of the three phases, the phase transition order is determined from α to γ phase with cooling, which is in agreement with the experimental result. The physical properties such as elastic constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and anisotropy factor are also discussed and analyzed, which indicates that the three structures are mechanically stable and each has a ductile feature. The Debye temperature is deduced from the elastic properties. The total density of states(TDOS) and partial density of states(PDOS) of the three phases are investigated. The TDOS results show that the γ phase is most stable with a pseudogap near the Fermi level, and the PDOS analysis indicates that the conduction band of the three phases is composed mostly of Mg-3s,Ag-4d, and Sb-5p. In addition, the changes of the free energy, entropy, specific heat, thermal expansion of γ-MgAgSb with temperature are obtained successfully. The obtained results above are important parameters for further experimental and theoretical tuning of doped MgAgSb as a thermoelectric material at high temperature.