精品课程建设为大学物理课程教学基本要求实施奠定基础

本文介绍了对理工科类大学物理课程教学基本要求的实施与完善教学试点工作的进展情况．提出高等院校大学物理课程如何与《新课标》高中物理的有机衔接是面临的新课题,对本校大学物理课程内容、教学过程基本要求执行方案进行了梳理总结,并提出了进一步的试点方案．     

多通道辐射高温计与VISAR的联合诊断技术

 利用二级轻气炮加载手段,开展了多通道辐射高温计结合可测量任意反射表面速度干涉仪（VISAR）的联合诊断技术研究。通过测量钽酸锂单晶的冲击相变,以确定联合诊断技术的可行性。结果显示,在同一发实验中,成功地获得了样品的界面速度剖面和光谱辐亮度历史,由此得到了钽酸锂单晶冲击相变的实验证据,表明该联合诊断技术是可行有效的。该技术对今后开展其它材料的高压物性研究具有一定的参考价值。     

MgB2超导薄膜制备方法对比研究

文章结合MgB2超导薄膜在电子器件中的应用,简介了混合物理化学气相沉积法、脉冲激光沉积法、磁控溅射法、分子束外延法和电子束蒸发法等MgB2超导薄膜制备方法和研究进展,并对主要的MgB2超导薄膜制备方法进行了比较,提出了改进意见.对MgB2超导薄膜的应用前景作了展望.     

Resonances in Electron Impact on Atomic Oxygen

The momentum-space coupled-channels-optical （CCO） method is used to study the resonances in electron oxygen collision in the energy region of 9-12 eV, Present results have shown agreement with the available experimental and theoretical results, and new positions of resonances are found by the comparison of total cross sections,     

Blue-to-Orange Tunable Luminescence from Europium Doped Yttrium--Silicon--Oxide--Nitride Phosphors

Europium-doped yttrium-silicon-oxide-nitride phosphors are synthesized by carbothermal reduction and nitridation method. The crystal structure of the phosphors changed gradually from oxide Y2Si2O7 to nitride YSi3N5 state with increasing dosage of Si3N4 and carbon powder. The Y2Si2O7：Eu phosphor shows a blue emission at 465 nm with 300 nm excitation and a characteristic red emission of Eu^3＋ at 612 nm with 230 nm excitation. The YSi3N5：EU phosphor shows a broad emission band centred at 595nm with some sharp peaks of Eu^3＋ with 325nm excitation. The absorption of the studied phosphors increases from 450 to 700hm with an increment in nitrogen content. Blue-to-orange tunable luminescence is observed with 390 nm excitation.     

Common Features in Electronic Structure of the Oxypnictide Superconductors from Photoemission Spectroscopy

High resolution photoemission measurements are carried out on non-superconducting LaFeAsO parent com- pound and various superconducting RFeAs（O1-ZFx） （R=La, Ce and Pr） compounds. It is found that the parent LaFeAsO compound shows a metallic character. By extensive measurements, several common features are identified in the electronic structure of these Fe-based compounds： （1） 0.2 eV feature in the valence band, （2） a universal 13-16 meV feature, （3） near EF spectral weight suppression with decreasing temperature. These uni- versal features can provide important information about band structure, superconducting gap and pseudogap in these Fe-based materials.     

Stochastic Resonance in an Over-Damped Bias Linear System with Dichotomous Noise

The stochastic resonance in an over-damped bias linear system subject to multiplicative and additive dichotomous noise （DN） is investigated. By using the linear-response theory and the properties of the DN, the exact expressions are found for the signal-to-noise ratio （SNR）. It is shown that the SNR is a non-monotonic function of the correlation time of the additive DN, and it varies non-monotonically with the bias of the external field, the intensity and asymmetry of the multiplicative DN, as well as the external field frequency. Moreover, the SNR depends on the bias of the system, as well as the strength and asymmetry of the additive DN.     

Behaviour of Self-Standing CVD Diamond Film with Different Dominant Crystalline Surfaces in Thermal-Iron Plate Polishing

Self-standing CVD diamond films with different dominant crystalline surfaces are polished by the thermal-iron plate polishing method. The influence of the dominant crystalline surfaces on polishing etfficiency is investigated by measuring the removal rate and final roughness. The smallest rms roughness of 0.14 μm is measured with smallest removal rate in the films with the initial （220） dominant crystalline surface. Activation energy for the polishing is analysed by the Arrhenius relation. It is found that the values are 170kJ/mol, 222kJ/mol and 214kJ/mol for the film with three different dominant crystalline surfaces. Based on these values, the polishing cause is regarded as the graphitization-controlling process. In the experiment, we find that transformation of the dominant crystalline surfaces from （111） to （220） always appears in the polishing process when we polish the （111） dominant surface.     

红外光谱预处理中去噪的研究

红外(IR)光谱由于包含了噪声等各种外界干扰因素.应该先进行光谱预处理,以便降噪,提高分析准确度.本文采用了一种基于最优小波包基的信号去噪算法,该算法根据最小代价原理,采用不同的阈值算法对光谱的高频和低频信号进行量化处理,用量化后的系数重构得到去噪信号,从而达到较好的去噪效果.实验表明,本方法处理后光谱曲线非常光滑、噪声消除效果明显.     

Electro-Magnetic Control of Vortex Shedding Behind a Circular Cylinder

Both open- and closed-loop control algorithms have been developed for suppressing of vortex shedding behind a circular cylinder in an electrically low-conducting fluid. For the open-loop control, the localized Lorentz forces are generated parallel to the cylinder surface, which have the accelerated effect to the fluid. Furthermore, two closed-loop control methods have been derived from the equations of motion capable of determining at all times the intensity of the Lorentz force to control the vortex shedding of a cylinder.