全固化单频激光器的控温系统

文章介绍了一种全固化单频激光器的控温系统，该系统利用PID控制原理，针对我们的控制对象，对其参数和整个系统进行了优化设计，并采取一系列抗干扰措施，保证了系统的控制精度和控制速度，用单片机对其多路温度信号的测量和显示进行了程序化控制，有效解决了热敏电阻的非线性问题，简化了系统的硬件结构，该系统体积小，运行可靠，控制精度达0．005℃（4h）。     

叉形光栅法产生分数阶涡旋光的实验探究

衍射和光栅是基础光学课程和光学实验的重要内容，在传统光学技术和前沿科学研究中有重要的作用和应用。文章以分数阶涡旋光为研究对象，利用空间光调制器设计了基于叉形光栅的衍射效应产生分数阶涡旋光的实验，编写了分数阶叉形光栅的计算机程序，实验上产生和观测了分数阶涡旋光，分析了分数阶涡旋光的特点和强度分布。通过本实验，学生进一步加深了对衍射和光栅特性的理解，激发了对光学前沿研究和探索的兴趣，拓展了学生的专业知识，提升了对光学研究和光场调控的创新意识。     

面向拔尖人才培养的大学物理实验教学改革实践

通过引入科研训练实验项目，成立课外实验探索小组以及组织各类学科竞赛等实验教学改革措施，进一步发挥了物理实验室的资源优势，理顺了相关管理制度，为学生营造了课内外融合的探索和创新实践环境，丰富了物理实验教学内容，提高了物理实验课程的趣味性和挑战度，有效促进了物理实验教学改革和拔尖人才培养。     

BN纳米管——一种新型的纳米材料

文章综述了BN纳米管的最新进展，介绍了BN纳米管的结构和制备技术发展情况，包括电弧放电，电弧熔融，激光烧蚀，机械球磨，碳纳米管取代反应答经学反应法，探讨了BN纳米管的机械和电学性质，并展望了BN纳米管的应用前景，提出了BN纳米管的发展方向。     

地震预测与统计物理

将现代统计物理学的理论和方法应用于地震和地震预测问题的研究，近年来取得了长足的进展，成为物理学和地震学之间一个最为活跃的交叉领域，这一领域所取得的成果，例如，将地震作为一种临界现象的模型，不仅丰富和深化了对地震的认识，而且改变了地震预测研究中的一些传统观念。文章介绍了这方面的研究进展，讨论了与这一领域相关的一些重要的物理概念和悬而未决的科学问题。     

各向异性晶体波导的倍频理论和实验研究

在波导耦合理论基础上，根据平面波导和通道波导的具体结构，分别推导了二种波导的倍频转换效率表达式，讨论了各种因素对倍频效率的影响，并采用离子法制备掺氧化镁铌酸锂和钽酸锂波导，测试和分析了它们的倍频性能，讨论了比较了平面和通道波道的特点。     

评介《材料科学导论——融贯的论述》一书（冯端、师昌绪、刘治国主编，化学工业出版社出版）

材料是人类文明的基础．从用火改造地壳物料，制作陶器，提高人类生活水平，进而在中国发明瓷器，已经分别经历了一万多年和两千年．人类利用矿石冶炼，制作出铜器和铁器也已分别有五千年以上和三千多年的历史．中国劳动人民在卓越的青铜铸造技术的基础上．创造了生铁，发明了用生铁在固态或半液态炼钢的技术，大大促进了工农业生产、贸易、经济和国力，为世界华夏文明奠定了物质基础．欧洲在19世纪中叶发明了用生铁为原料的液态炼钢，大大促进了生产力和国力的发展，为当代的西方文明的发展和扩张创造了条件．但是直到20世纪中     

光纤X射线探针和测量系统

利用Ｘ射线在探针中的康普顿散射以及电子在光纤中的契仑柯夫效应可以构成光纤Ｘ射线探针和测量系统，本文对此做了理论和实验研究，推导了光纤探针的灵敏度公式，给出了计算结果，并做了实验标定，讨论了光纤探针测量系统的构成，测量的动态范围和响应时间。     

γ射线爆的研究进展—20世纪天体物理第三次大辩论

γ射线爆的研究已经历了２０余年，无论观测上或者理论上，均已积累了大量的数据和资料，构思了不少想法和模型，然而，１９９１年ＣＯＭＰＴＯＮ ＧＲＯ天文卫星上天以后，一系列的观测结果将这个领域推向空前激动人心的前沿，矛盾十分突出，几乎要求从头重新研究，对γ射线爆的时间特征，能谱性质，辐射区物理，空间分布等方面，进行了分析和讨论，阐述了近年来的研究进展，指出了存在的主要问题以及这个领域研究的重要意义。     

微小光学的研究现状

叙述了微小光学的新进展，对微小光学基本原理给出了简单概括，并对发展动态进行了评论，在微小光学理方面，讨论了“阵列光学”理论，研究了光学阵列的物与共轭象间的关系；在微小光学器件方面，讨论了变折射率透镜，平面微透镜列阵，衍射光学元件和三维集成光学系统；在应用方面，讨论了和并行光通信，光计算有关的一些新应用。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.