数字图书馆与普通图书馆的差异

数字图书馆不是传统图书馆的数字化翻版,它是通过对有高度价值的图像、文本、语言、音响、影像、影视、软件和科学数据库等多媒体信息进行收集,组织规范化的加工,进行高质量保存和管理,实现知识增值,并提供在广域网上高速横向连接的电子存取服务.     

微通道介电泳颗粒流动中的焦耳热分析

微通道中的介电泳颗粒流动是芯片实验室装置的最重要应用之一.生物和医学领域的实际应用中,为获得足够的介电泳颗粒控制能力,在高电导率的电解溶液上施加强电场,而这将引起溶液温度的明显升高.本文建立了介电泳颗粒流动中的电场分布和焦耳热效应的理论模型.对介电泳微通道中电解溶液中的电场与温度场进行了计算,分析了介电泳作用下产生的焦耳热对微通道内温度场的影响.     

Intersubband transitions in InxAl（l-x）N/InyGa（l-y）N quantum well operating at 1.55 μm

In this paper, we theoretically study the effects of doping concentration ND and an external electric field on the intersubband transitions in InxAl（l-x）N/InyGa（l-y）N single quantum well by solving the Schrodinger and Poisson equations self-consistently. Obtained results including transition energies, the band structure, and the optical absorption have been discussed. The lowest three intersubband transitions （E2 -El）, （E3 -El）, and （E3 -E2） are calculated as functions of doping concentration ND. By increasing the doping concentration ND, the depletion effect can be reduced, and the ionized electrons will compensate the internal electric field which results from the spontaneous polarization. Our results show that an optimum concentration ND exists for which the transition 0.8 eV （1.55 μm） is carried out. Finally, the dependence of the optical absorption α13（ω） on the external electric field and doping concentration is studied. The maximum of the optical absorption can be red-shifted or blue-shifted through varying the doping concentration and the external electric field. The obtained results can be used for designing optical fiber telecommunications operating at 1.55 μm.     

Self-accelerating and self-breathing Bessel-like beams along arbitrary trajectories

We theoretically and experimentally study self-accelerating and self-breathing Bessel-like beams that fol- low arbitrary trajectories, including hyperbolic, hyperbolic secant, and three-dimensional （3D） spiraling trajectories. The beams have an overall Bessel-like profile in transverse dimensions; however, the intensity of their central main lobe breathes while traveling along a curved trajectory. Such beams can be readily generated experimentally through appropriate phase modulation of the optical wavefront. The beams con- tribute to the design of new families of self-accelerating beams.     

应用双面电极的PLZT横向电光调制器电场的精确解

使用保角变换方法导出了横向电光调制器中双面电极结构的电场和电容的解析表达式，给出了用于ＰＬＺＴ电光陶瓷介质中二次电光效应分析的电场分布的物理图像。通过计算对比表明，双面电极结构电极边级区域由于过剩双折射引起的强度调制非均匀性较单面电极有所改善。     

高频电场处理水泥浆改善其物理特性的实验研究

介绍了利用高频场处理经浆，改善固井水泥浆流变性和水泥抗压强度的实验结果，初步探讨了作用机理。     

高温超导体电场穿透对电子能谱的影响

高温超导体在场致发射时伴正常态部分的空穴的产生，会出现非平衡现象。这引起超导体电子平衡态的化学势偏移，增加了外电场在ＨＴＳＣ材料体内的穿透深度，使导带底弯曲引起超导体场致发射电子能谱的改变。