关于DIS实验流程模式的理论探究

首先针对目前数字化实验教学研究重实践、轻理论的现状,指出了实验教学理论研究的必要性和紧迫性。然后根据DIS实验系统的特点和对实验教学过程的影响,提出了包含5个功能层面的完整实验体系的理论构想和实验流程模式的概念,并重点按照新的理论构想和分析方法,探讨传统实验和数字化实验在流程模式上的明显区别以及对课堂效果的影响,最后对DIS实验未来的发展提出建议。     

全面认识物理理论与物理实验的关系

物理实验与物理理论之间的关系是讲授物理实验课时首先应向学生阐明的问题。现行的物理教材（中专和大学）一般是这样概括物理实验和物理理论之间的关系：物理学是一门建立在物理实验基础上的学科。物理学的原理、定理是在总结大量的物理实验事实基础上概括出来的．这些论述强调了物理理论对物理实验的依赖性，无疑是正确的．但却忽视了物理实验与物理理论的另一方面：即物理实验对物理理论同样具有依赖性，这一点也很少受到物理学工作者和物理教师的注意．全面认识物理理论与物理实验的关系，对于我们更好地进行物理实验的研究和物理实验的…     

理论和实验的关系

 有时理论和实验两者都是正确的,但彼此不相符合;有时错误的理论却与实验符合。因此,必须慎重,不要急于下结论。通常,人们期望理论能够解释现有的实验结果及预言新的结果,而实验则用来检验理论的正确性和收集数据,以便修正理论。这种处理问题的方法常常作为“好”科学的金科玉律传授给学生。实际上,在某些情况下,上述目标是可以实现的,但有时把理论和实验作比较可能会误入歧途。     

电磁学理论教学与实验如何有效结合的思考

电磁学是一门与实验紧密相关联的理论课程。笔者在多年从事电磁学教学过程中,对电磁学理论教学和实验教学如何有效结合,进行较深入的思考与实践,其中包括大学物理实验课程中的电磁学实验与电磁学课程理论教学内容协调统筹设置和安排,电磁学理论教学与课堂演示实验的有效配合,设置电磁学设计性实验与电磁学理论教学相结合,以及建设电磁学专业实验室的必要性。     

圆柱形水下爆炸实验容器壁部强度设计研究

 基于薄壁壳理论和水下爆炸理论,对圆柱形水下爆炸实验容器在爆炸冲击波作用下弹性范围内的壁部应变进行了理论分析和实验研究。导出了圆柱形水下爆炸实验容器在爆炸冲击波作用下壁部弹性应变与容器直径、壁厚及内部爆炸药量之间的关系,并对计算结果进行了实验验证。实验表明公式求解结果与实验结果具有较好的一致性。     

被动锁模中第二阈值的统计特性

使用不同染料,在以Nd:YAG和钕玻璃为激活介质的激光腔中对被动锁模的统计特性详细作了理论和实验研究。实验结果与理论进行了比较.对Nd:YAG可很好地证实理论,亦能对钕玻璃理论与实验的矛盾作定性的解释.     

基于声光效应的声速实验测量和理论模拟计算

本文利用声光效应对晶体中声速进行实验测量,通过Matlab编程实现图像识别和数据处理。同时结合以量子力学为基础的密度泛函方法对晶体声速进行理论模拟计算,并对实验结果和理论模拟计算数据及参考文献中的数据进行了对比和讨论,分析了实验中可能产生误差的因素。发现利用计算机对实验图像识别和数据处理可以有效提高实验精度,为将来在高校中开展声光效应相关实验设计和理论模拟计算提供参考。     

对电工学实验指导的探讨

电工学实验赴电工学课程的一个重要教学环节。通过实验,使学生在电工方面受到基本技能的训练,巩固基本理论,扩大基本知识,以及培养学生分析问题、解决问题的能力。为了提高实验教学质量,多年来,我们除了对实验内容进行调整和充实外,对实验指导方面也不断进行探索和改革。过去的实验,以验证理论为主,做实验的目的主要是获得符合理论的结果。实验指导教师极力创     

缪轻子反常磁矩和北京谱仪实验

最新的缪子反常磁矩实验测量结果与标准模型理论预言偏离4.2σ,提供了新物理存在的重要证据。然而要确认新物理的存在,实验和理论还需要进一步提高精度。运行在量子色动力学微扰与非微扰过渡能区的北京谱仪实验能够约束缪子反常磁矩理论计算中最重要的误差来源——强相互作用的修正。文章介绍了缪子反常磁矩的实验与理论现状,特别是北京谱仪实验上相关的研究成果,并展望了未来缪子反常磁矩的实验测量与理论计算。     

两相闭式热虹吸管内凝结换热的研究

本文对竖直两相闭式热虹吸管内的凝结换热进行了理论分析和实验研究。理论分析中考虑了两类不同的界面切应力的影响和饱和压力的影响。在不同充液量和不同压力下进行了实验,实验结果在一定的温差范围内与理论分析值符合较好。     

Electronic structure of hydrogen and muonium in Al,Mg and Cu

The electronic structure of hydrogen and muonium in simple metals is investigated. The spherical solid model potential is used for the discrete lattice and the Blatt correction for lattice dilation. The proton and muon are kept at the octahedral sites in the fcc and hcp lattices and self-consistent non-linear screening calculations are carried out. The scattering phase shifts, electronic charge density, effective impurity potential, self-energy, charge transfer, residual resistivity and Knight shift are calculated. The spherical solid potential changes the scattering character of impurity. The phase shifts are found slowly converging. The scattering is more prominent in Al than in Mg and Cu. The virtual bound states of proton and muon are favoured in all the three metals. The calculated value of residual resistivity for CuH is in good agreement with the experimental value. The results for Knight shift forμ ⁺ in Cu and Mg are in reasonable agreement with the experimental values while those forμ ⁺ in Al are lower than the experimental value. The analytical expressions for effective impurity potential and electronic charge density are suggested.     

Nonlinear cyclotron-impurity resonance in semiconductors

The nonlinear absorption of electromagnetic radiation by electrons in a quantizing magnetic field is investigated. The inclusion of multiphoton processes is shown to result in additional peaks in the absorption curve. The shape and arrangement of these peaks were found. The absorption is shown to depend on the electric field strength in the electromagnetic wave nonlinearly and nonmonotonically. The results obtained are in good agreement with experimental data.     

生物芯片扫描仪研究进展

介绍了生物芯片及其检测、扫描的基本原理。详细讨论了在生物芯片扫描仪中的关键技术及国内外的研究现状和目前存在的技术难点以及最新发展趋势和研究热点。着重分析了共聚焦光路与非共聚焦光路在生物芯片扫描仪中的应用特点,以及CVR技术指标。最后提出了生物芯片扫描仪的未来研究重点以及发展方向。     

Higher-order squeezing and sub-poissonian photon statistics in CARS and CAHRS

The Squeezing and sub-poissonian photon statistics of an optical field are a purely quantum mechanical phenomenon and has been accepted as means of achieving noise below the quantum shot-noise limit. The effect of higher-order squeezing and sub-poissonian nature of an optical field in coherent anti-Stokes Raman scattering (CARS) and coherent anti-Stokes hyper Raman scattering (CAHRS) are investigated under short-time approximation. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established and solved under short-time scale. The dependence of squeezing on the number of photons is also investigated. It is also shown that higher-order squeezing allows a much larger fractional noise reduction than lower-order squeezing. The occurrence of amplitude squeezing effects of the radiation field in the fundamental mode is investigated in both the processes. The present work shows that squeezing is greater in CAHRS than the corresponding squeezing in CARS. It is also shown that squeezing is greater in stimulated process than corresponding squeezing in spontaneous interaction. The conditions for obtaining maximum and minimum squeezing are obtained. The photon statistics of the pump mode in the processes has also been investigated and found to be sub-poissonian in nature.     

Investigation on the electronic transport properties of MgS nanotube based molecular devices – a first-principles study

The electronic transport properties of pure MgS nanotube based molecular devices, Mn-substituted nanotubes and Se-substituted nanotubes are investigated using density functional theory. The state of the art of this work is to study the transport properties of MgS nanotubes with substitution impurities across electrodes. The electronic transport properties are discussed in terms of device density of states and transmission spectrum of MgS nanotubes. The effects of Mn substitution and Se substitution in nanotubes are studied. The major contribution to density of states arises only from p orbitals in MgS nanotubes. The substitution effect and bias voltages also have influence in the density of states. The transmission spectrum provides information about the transmission of electrons along the nanotube. The information provided in this work gives a clear vision to fine-tune MgS nanostructures with improved transport property in nanoelectronic device fabrication.     

Prevalence of spontaneous otoacoustic emissions in neonates.

The prevalence of spontaneous otoacoustic emissions (SOAEs) was measured in a group of 100 neonates and in a group of 50 normal-hearing young adults. The prevalence of SOAEs in the adult group (0.62) is at the high end of the range of prevalences reported in other surveys of adult SOAEs based on measurements using similar microphones. The prevalence of SOAEs in neonates (0.64) is not significantly different from that in adults. The various tendencies that have been found to be significant in the pooled results of other surveys are also evident in our adult group: more SOAEs in right ears, a higher prevalence of SOAEs in females, and a dependence between ears for the occurrence of SOAEs. The above-mentioned tendencies are also significant in the infant data. The major differences between the infant and adult results are the predominant SOAE frequency range and the average levels of SOAEs. The majority of adult SOAEs are between 1.0 and 2.0 kHz, whereas the majority of neonatal SOAEs are between 2.5 and 5.0 kHz. The average SOAE level is -2.6 dB SPL for adults and 8.5 dB SPL for infants.     

氧化铁浆液脱硫的实验研究与理论分析

本文实验研究了氧化铁浆液在酸性环境下脱除烟气中的二氧化硫气体。实验在一自制的脱硫塔中进行。通过燃烧液化石油气来产生烟气,将氧化铁的超细粉加入水中作为脱硫介质。实验中研究了二氧化硫初始浓度、水气比对脱硫效率的影响。从实验结果可以看出,脱硫率随着水气比的增加而增大;随二氧化硫的初始浓度的增加,其脱硫率呈降低趋势。在文中同时分析了氧化铁浆液的脱硫机理和此方法脱硫的优点以及目前存在的问题。     

Analysis of dusty plasma in the positive column of glow discharges

The radial distributions of ions,electrons and dust particles in the positive colum of glow discharges are investigated in a tripled-pole diffusion model.The dust particles are mainly trapped in the region around the column axis where the electrostatic potential is the highest.The presence of the dust particles results in the ion density increasing and the electron density decreasiung in the dust-trapped region.The dust-trapped region is wider for a higher dust temperature or a smaller particulate redius.The ions and electrons in the dust-free region away from the column axis are in ambipolar diffusion.     

FAAS法测定土壤和蔬菜中的Cd元素

本文以油菜为试材，用ＦＡＡＳ法对受Ｃｄ污染土壤中的全量Ｃｄ、有效态Ｃｄ以及油菜茎叶中的Ｃｄ含量进行了测定与分析。同时对土壤全量Ｃｄ、有效态Ｃｄ及茎叶中Ｃｄ的样品予处理方法进行了比较研究。结果表明，方法回收率在９６％以上，样品测定的相对标准偏差小于３．９７％。本方法快速、准确、干扰少。测定结果满意     

Vapour and plasma ignition thresholds for visible pulsed-laser ablation of metallic targets

The coupling of visible nanosecond laser pulses to metallic targets irradiated in vacuum is studied. The expressions of the vapour and plasma ignition times are obtained. Two cases for vapour breakdown in the plasma ignition process are considered. The first case is that 40 generations of new electrons are born in vapour generation time before plasma formation as assumed in the literature. The second case is that 10 generations of new electrons are born in vapour generation time. Molybdenum (Mo), niobium (Nb) and aluminium (Al) targets are considered for illustrations of our results. The expression of the plasma ignition time for the Al target is substantially different from that reported in the literature. The vapour and plasma ignition threshold laser intensities are calculated and compared with those reported in the literature. Reasons for disagreement are discussed. The plasma ignition threshold estimated in the second case is noted to be in good agreement with the reported experimental result.