基于气体吸收理论的激光光谱气体在线监测技术研究

气体对激光能量的吸收是一种比较普遍的吸收现象,本文利用可调谐半导体激光吸收光谱技术,依据大学物理光学部分的比尔-朗伯尔定律为依据,通过气体吸收实验验证了气体的基本吸收理论,获得了760.77nm吸收波长处不同氧气浓度情况下的基本吸收谱线幅值,得出了气体浓度越高,对光的吸收也越强的结论.并进一步对实验数据进行曲线拟合,使学生深入理解曲线拟合方法在气体浓度监测方面的应用.通过本实验可以增加学生的视野和对新技术的了解,以及对气体吸收理论的进一步理解.     

基于回音壁微球腔的共振现象实验教学设计研究

大学物理实验教学是巩固理工科类专业学生大学物理基础知识、培养其实验方法和创新技能的重要教学手段。本文探讨了将当前热门研究课题回音壁微腔中蕴含的共振现象引入到大学物理实验教学中，利用回音壁微球腔中共振模式的测量实验开展完整、新颖的实验教学设计和实验流程，达到丰富大学物理实验教学内容，同时提高学生分析问题、动手实践和创新思维能力的教学目的。     

麦克斯韦速率分布的特色推导方法

大学物理教学的一个基本点是培养学生的空间想象力.麦克斯韦速率分布律是气体分子运动论的中心内容,是大学物理气体运动理论中讲授的一个难点,其公式抽象、繁难,学生不易理解.本文根据速度空间概念,给出速度球的表面积相当于气体分子微观状态数的观点,利用拉郎格日函数,推导理想气体平衡态下气体分子的速率分布函数.这种推导方法相对比较...     

分子力对气体输运系数的影响

在气体输运过程中,把气体分子看作有引力的弹性球,研究了分子力对气体输运系数的影响,对普通物理中的气体动理论给出的输运系数与气体温度的关系进行了修正,使之更接近于实验结果.     

气体的红外光谱检测教学设计研究

大学物理实验是高等院校培养理工科学生实验综合水平的基础课程。本文探讨了将大学物理实验与应用相结合的前沿研究课题,设计了新颖、完整的实验和流程,使学生能够真正在物理实验的过程中巩固理论知识、学习实验技能、提高思维能力、锻炼创新意识,更好的达到实验教学的真正目标。     

“新工科”背景下大学物理实验教学中课程思政的探索与实践

在新工科背景下,各高校都在积极探索大学物理实验课程思政的教学改革之路。大学物理实验课程体现了培养学生的创新能力和科学素养,这一点也切合了适应新工科创新能力及科学素养培养为导向的教育理念。在面向未来新技术和新产业发展,提出了针对不同专业学生,以新技术需求为导向,以实际问题为驱动,以实验项目为链条,体系化设计大学物实验内容并深入挖掘课程思政元素,构建大学物理实验课程思政新体系,对贯彻新工科“立德树人、塑造未来”育人理念下的大学物理实验课程思政教学有一定的借鉴意义。     

在物理实验教学中培养学生的科学实验素质和能力

物理教学包括理论教学和实验教学, 重点阐述了在大学物理实验教学中培养学生科学实验素质和能力 的重要性. 以变阻器的使用与电路控制为例论述了如何启发和指导学生根据实验要求自行设计实验方案、 开展实验 实践、 分析实验数据, 根据实验结果对实验方案和实验实践进行改进. 通过设计性实验, 让学生深刻理解科学实验的 全过程, 进而培养学生的科学实验素质和能力, 实现大学物理教学的最终目标     

杠杆式回转仪定量演示方法研究

在对杠杆式回转仪运动现象进行理论分析的基础上,通过测量出圆轮自转角速度,旋转轴进动角速度、进动角度的参数,定量研究了力矩与进动速度间关系、角速度与进动速度间关系、角动量定理的实验验证,最后将测量值与理论计算值进行了比较。将杠杆式回转仪运动状态的定量分析引入大学物理实验,培养了学生实际动手能力,加深了学生对角动量定理,力...     

大学物理实验的双语教学设计

在教育国际化、信息化的背景下,培养创新型国际化的人才是双语教学的目的。开展大学物理实验双语教学将有助于发挥物理实验和双语教学两者的优势,不仅会促进学生的专业研究,而且也会提高学生的外语水平。本文在文献综述的基础上,界定了双语教学的概念,并对大学物理实验双语教学的可能性与必要性进行了分析。文中还讨论了大学物理实验双语教学的设计,给出了具体的教学案例,并针对目前大学物理实验双语教学理论和实践中存在的问题提出了一些思考和解决途径。     

数字电表原理及万用表设计实验教学模式探讨

在大学物理课程及实验教学中开设数字电表原理及应用技术实验,对传统电表的改装校准实验进行教学模式改革,内容更新颖,可操作性、实用性更强。并且将数字电表实验与传统电表改装校准实验对比进行教学模式分析探讨,实验原理的教学讲解更清楚,有效激发学生进一步设计性数字电表实验的兴趣,自己设计实验激发了学生学习的主动性,拓展了学生的思维能力,培养了学生的创新能力。对工科专业学生作用明显。     

Effective theory of excitations in a Feshbach-resonant superfluid

A strongly interacting Fermi gas, such as that of cold atoms operative near a Feshbach resonance, is difficult to study by perturbative many-body theory to go beyond mean-field approximation. Here I develop an effective field theory for the resonant superfluid based on broken symmetry. The theory retains both fermionic quasiparticles and superfluid phonons, the interaction between them being derived nonperturbatively. The theory converges and can be improved order by order, in a manner governed by a low energy expansion rather than by a coupling constant. I apply the effective theory to calculate the specific heat and discuss the theory with a recent heat capacity experiment.     

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介绍了自行研制的直流非转移弧等离子体炬的结构和工作原理。运用相似理论,研究了该等离子体炬的电热特性与运行参数,比如气体流量、弧功率的关系,并将计算值与实验结果进行了比较。结果表明,计算值与实验结果吻合较好,可以利用获得的公式来对炬进行结构改进和参数优化。     

Measurement of decoherence of electron waves and visualization of the quantum-classical transition

Controlled decoherence of free electrons due to Coulomb interaction with a truly macroscopic environment, the electron (and phonon) gas inside a semiconducting plate, is studied experimentally. The quantitative results are compared with different theoretical models. The experiment confirms the main features of the theory of decoherence and can be interpreted in terms of which-path information. In contrast to previous model experiments on decoherence, the obtained interferograms directly visualize the transition from quantum to classical.     

Measurement of avalanche size and position resolution of RPCs with different surface resistivities of the high voltage provider

The effects of surface resistivity of the high voltage provider on the space dispersion of the induced charge of a prototype Resistive Plate Chamber （RPC） have been studied experimentally and theoretically. The results of both experiment and theory agree and confirm that a two-Gaussian function can be used to fit the dispersion of the induced charge of the RPC. It is shown that the Gaussian function with the narrower width is mainly due to the expansion of the avalanche charge in the gas gap of the RPC, and the Gaussian function with the larger width is due to the charge dispersion when it passes through the resistive carbon film. This will be useful in the RPC design when one wants to make an RPC with high position resolution.     

Compression of positron clouds using rotating wall electric fields

An asymmetric dipolar rotating electric field can be used to compress a trapped cloud of positrons when applied with a frequency close that of their axial bounce, and in the presence of a low pressure molecular gas to provide cooling. Measurements of the compression rate and associated parameters are presented and compared with results of a theory we have developed. The latter treats positron behaviour in a perfect Penning trap potential, in the presence of the rotating field, with the cooling modelled in the Stokes viscous drag approximation. Good agreement between the theory and experiment has been found, which has allowed us to identify the phenomenon as a new form of sideband cooling.     

碳纳米管场发射特性研究

从Fowler-Nordheims理论出发,对实验中测得的碳管场发射中ln(I/V²)～1/V并不是严格的线性关系进行了分析,认为主要是碳管吸附态(主要是水蒸气)的改变引起有效功函数改变,同时随着发射电流的增大,个别较长碳管表面的突起在残余气体离子轰击下变得平滑甚至缩短,热熔化也可能造成碳管缩短.另一方面,随着电场强度的增大,较短碳管的场发射对总发射电流的贡献也相对提升.这些因素都会造成场发射中F-N曲线的斜率发生改变.     

聚乙烯与水反应的高温高压实验及热力学探讨

 在金刚石压腔设备中进行聚乙烯的高温高压裂解实验研究。实验分含水和不含水两种情况。在显微镜下观察反应过程中的变化并显微照相记录有关现象,在高压下就位测定反应过程中荧光的变化。用气相色谱方法测定气相产物组成。含水实验中CH₄占烃类气体产物的92%并有CO₂生成,固体残余物非常少,表明水直接参与了化学反应,为烃类气体的形成提供氢源,为CO₂的形成提供氧源。不含水实验中烃类气体的产率相对较低并有较多的固相残余物存在。用热力学理论探讨了实验中有关反应的机制。根据聚乙烯与干酪根结构的可比性,推测在水参与条件下有利于提高有机质裂解成烃的产率。     

Utilizing Experiment and Theory to Evaluate Rhodamine B ethylenediamine as a Fluorescent Sensor for G-type Nerve Agents

Nerve gas mimic binding with Rhodamine B ethylenediamine (1) was studied in organic media. Binding of the nerve gas mimic, diethyl chlorophosphate (DCP), with the probe generated a non-fluorescent intermediate and a fluorescent product. Fluorescent and non-fluorescent products generated were identified using mass spectrometry and X-ray crystallography. Time-dependent density functional theory calculations were also used to investigate the electronic structure of the fluorescent probe in the ground and lowest lying π?→?π* singlet excited state. Though good agreement between theory and experiment can be obtained for the intense peak in the experimental spectrum using non-hybrid functionals, care must be taken when modelling these complexes due to the appearance of an n?→?π* transition that is too low in energy and appears to fall in the shoulders of the π?→?π* transitions.

     

致冷剂简单气体水合物相平衡计算

本文从统计热力学理论出发,结合ｖａｎｄｅｒＷａａｌｓ－Ｐｌａｔｔｅｅｕｗ理想固溶休假设。给出ＨＦＣ１５２ａ和ＨＣＦＣ１４１ｂ简单气体水合物相平衡计算模型,并进行计算。计算结果与实验数据进行比较,很好吻合,正确反映了简单致冷剂水合物的相平衡规律。本研究为进一步混合气体水合物相平衡计算打下基础。     

Interfacing Mercury Porosimetry with Nitrogen Sorption

Combinations of gas sorption and mercury porosimetry experiments have been run in series on the same sample. This has been achieved by freezing entrapped mercury in place before a subsequent gas sorption experiment was carried out. Several different bidisperse materials with similarly shaped mercury intrusion curves and similar levels of mercury entrapment have been studied. The entrapment of mercury within certain pores in the porous medium can often lead to marked changes in the shape of the gas sorption hysteresis loop between the data obtained prior and subsequent to porosimetry. It was found that the degree of the change of shape of the sorption hysteresis loops differed markedly between different materials. The analysis of the gas sorption hysteresis loops using percolation theory has allowed information to be obtained on the pore length distribution, and/or the distribution of pore co‐ordination number and the spatial arrangement of pores within the sample, in addition to the pore connectivity and lattice size usually obtained. The interfaced experiments have also allowed the internal consistency of analysis methods based on percolation theory to be tested, semi‐empirical alternatives to the Washburn Equation for the analysis of raw mercury porosimetry data to be independently validated, and the mechanisms of mercury entrapment in various samples to be determined.