大学物理实验教学创新模式的探索与实践

通过认真学习《非物理类理工科大学物理实验教学基本要求》,提出一种大学物理实验课程的创新性补充模式,该模式在本校学生中付诸实践,取得了较好的效果.     

Application of high-precision temperature-controlled FBG filter and light source self-calibration technique in the BOTDR sensor system

A high-precision temperature-controlled narrow band-stop fiber Bragg grating(FBG) filter and light source self-calibration technique are proposed for application in the Brillouin optical time domain reflectometer (BOTDR) sensor system.With the proposed application,the BOTDR sensor system maintains good long-term stability and temperature precision through the reduction of the center wavelength drift in the FBG filters and corresponding decrease in the changes in light intensity.The experiment result shows that temperature precision of 1℃and temperature stability of 0.7℃can be achieved in a temperature sensor over a range of 8 km.     

食品微生物对超高压处理的逆境响应

 超高压（High Hydrostatic Pressure,HHP）作为一种非热杀菌技术,在食品工业中有着很广泛的应用,与传统的热加工处理相比,在保持食品品质、杀菌、钝酶等方面都有其明显的优势。通过对国内外相关文献的分析,对HHP处理后处于亚致死状态食品微生物的细胞膜、遗传与结构物质、机体代谢等方面,以及大部分食品微生物在应对外界的多种刺激时而进行的普遍性调控机制的研究进行了总结,探讨了经过HHP处理后处于亚致死状态的食品微生物在逆境下存活的应激反应。     

水下激光探测系统的水体后向散射光计算与光学参数估计

针对水下激光探测系统的水体后向散射光的计算,给出了系统的光学几何结构,分析了不同距离处的激光光斑与接收视场区域的位置变化关系并进行了定量计算。依据光传输理论建立了水体后向散射光的计算模型,根据模型的算法步骤编写了计算机程序。结合水下激光探测系统的具体参数进行了实例计算,绘制了后向散射光信号波形,并与试验获取的信号波形对比分析,验证了算法的可行性和正确性。研究了使用实测后向散射光信号数据估计水体光学特性参数的方法,通过估算的参数重新绘制曲线并反向叠加在测量数据曲线上以抵消水体后向散射光对目标信号的影响从而能够提取目标信息。     

Quantum correlations between two non-interacting atoms under the influence of a thermal environment

By considering a double Jaynes-Cummings model,we investigate the dynamics of quantum correlations,such as the quantum discord and the entanglement,for two atoms in their respective noisy environments,and study the effect of the purity and the cavity temperature on the quantum correlations.The results show that the entanglement suffers sudden death and revival,however the quantum discord can still reveal the quantum correlations between the two atoms in the region where the entanglement is zero.Moreover,when the temperature of each cavity is high the entanglement dies out in a short time,but the quantum discord still survives for quite a long time.It means that the quantum discord is more resistant to environmental disturbance than the entanglement at higher temperatures.     

Effects of carbon convection field on large diamond growth under high-pressure high-temperature conditions

Large diamond crystals were successfully synthesized by FeNi-C system using temperature gradient method under high-pressure high-temperature conditions. The assembly of the growth cell was improved and the growth process of diamond was investigated. Effects of the symmetry of carbon convection field around the growing diamond crystal were investigated systematically by adjusting the position of seed crystal in the melted catalyst/solvent. The results indicate that morphologies and metal inclusion distributions of the synthetic diamond crystals vary obviously in both symmetric and non-symmetric carbon convection fields with temperature. Moreover, finite element method was applied to analyze carbon convection mode of the melted catalyst/solvent around the diamond crystal. This work is helpful for understanding the growth mechanism of diamond.     

Stark位移对热环境下双Jaynes-Cummings模型中原子纠缠的影响

研究双光子跃迁的双Jaynes-Cummings模型中, 两原子初始处于最大纠缠态、光场初始处于单模热态时的原子纠缠动力学, 考虑双光子过程中的Stark位移、热光场的平均光子数对原子纠缠的影响. 结果表明: 不考虑Stark位移时, 两原子在系统演化过程中周期性地出现退纠缠现象, 而考虑Stark位移时, 两原子长时间地纠缠. 特别是当Stark位移参数取值较大且热光场的平均光子数值比较小时, 两原子能保持 稳定地纠缠. 这些结果表明, 可以利用Stark位移对热环境下双Jaynes-Cummings模型中的原子纠缠进行调控.     

Spectral Anomalies in the Fraunhofer Diffraction Pattern

We study the spectral characteristics theoretically and experimentally in the Fraunhofer diffraction pattern formed by the diffraction of a spatially coherent, polychromatic light through a slit. It is found that the spectrum in some diffraction directions close to the singular direction is redshifted, compared to the spectrum of the incident polychromatic light, and blueshifted in other directions, and splits into two lines at the singular direction. We show that the experimental results are consistent with the theoretical expectations.     

多孔介质BISQ模型中的慢纵波

着重研究了多孔介质BISQ模型中慢纵波的基本特性.给出了BISQ模型下慢纵波速度 和衰减的低频近似公式.与Biot理论对比，BISQ模型中慢纵波的衰减随频率降低急剧增大， 且随喷射流长度的减小而增加；相速度随喷射流长度的减小而增加，其低频极限值不是零； 孔隙流体位移与固相骨架位移之比的幅值随喷射流长度的增加而减小，其相位特点与Biot模 型预测的不同；在流体与孔隙介质的边界上可产生更大的渗流.为对比，同时也给出快纵波 的行为.依据BISQ模型可推断：非黏滞流体饱和孔隙介质中不存在喷射流机理；BISQ模型中 关键词： 多孔介质 喷射流 慢纵波 动力协调     

用线阵CCD标定光纤端部位置

为了标定光纤端部在平面上的位置,采用线阵CCD对光纤的出射光进行扫描,对于接收到的数据采用重心法进行处理,并通过改变实验条件以达到较为理想的结果。