类金钢石非晶碳薄膜的光吸收和光致发光研究

我们用激光轰击石墨靶成功地制备出类金刚石无氢非晶碳薄膜.测量了光学吸收、光致发光及其随入射光强度的变化关系.结果表明,这种薄膜具有类金刚石的性质,光学带隙在1.67-2.25eV,发光在可见光区呈宽带结构.低激发强度下发光强度超线性变化,而在高激发强度下则为线性发光.我们用非成对载流子复合的模型对结果给出了合理的解释.用带尾态饱和的模型解释了发光峰值随激发光强增加而蓝移的现象.     

On existence of solutions for some hyperbolic-parabolic-type chemotaxis systems

In this paper, we discuss the local and global existence ofweak solutions for some hyperbolic–parabolic systems modellingchemotaxis.     

Extension of Isometries Between the Unit Spheres of Normed Space E and C（Ω）

In this paper, we study the extension of isometries between the unit spheres of normed space E and C（Ω）. We obtain that any surjective isometry between the unit spheres of normed space E and C（Ω） can be extended to be a linear isometry on the whole space E and give an affirmative answer to the corresponding Tingley＇s problem （where Ω be a compact metric space）.     

On a micro‐macro model for polymeric fluids near equilibrium

In this paper, we study a micro‐macro model for polymeric fluid. The system involves coupling between the macroscopic momentum equation and a microscopic evolution equation describing the combined effects of the microscopic potential and thermofluctuation. We employ an energetic variation procedure to explore the relation between the macroscopic transport of the particles and the induced elastic stress due to the microscopic structure. For the initial data not far from the equilibrium, we prove the global existence and uniqueness of classical solutions to the system. © 2006 Wiley Periodicals, Inc.     

A Novel Analytical Approach for Multi-Layer Diaphragm-Based Optical Microelectromechanical-System Pressure Sensors

An optical microelectromechanical-system （MEMS） pressure sensor based on multi-layer circular diaphragm is described and analysed by using the proposed novel analytical approach and the traditional transfer matrix method. The analytical expressions of the deflection of multi-layer diaphragm and absolute optical reflectance are derived respectively. The influence of residual stress on the deflection of diaphragm is also analysed. Simulation results given by the finite element method are consistent with the ones which are analysed by using the analytical approach. The analytical approach will be helpful to design and fabricate the optical MEMS pressure sensors with multi-layer diaphragm based on Fabry-Perot interferometry.     

Microstructure array on Si and SiOx generated by micro-contact printing, wet chemical etching and reactive ion etching

A method, combining micro-contact printing (μCP), wet chemical etching and reactive ion etching (RIE), is reported to fabricate microstructures on Si and SiOx. Positive and negative structures were generated based on different stamps used for μCP. The reproducibility of the obtained microstructures shows the methodology reported herein could be useful in Micro-Electro-Mechanical Systems (MEMS), optical and biological sensing applications.     

Eu3+离子在微晶玻璃研究中的探针作用

制备出单掺Eu3+离子的氟氧化物玻璃陶瓷系列样品,利用Eu3+离子作为荧光探针,通过热处理前后Eu3+离子发射光谱中电偶极子跃迁与磁偶极子跃迁强度比值的变化表征在玻璃材料中微晶是否形成,分析了Eu3+离子荧光发射谱中电偶极子跃迁与晶体场对称性的关系,进一步表征了稀土离子所处微晶晶格场的变化.     

径向剪切干涉法综合诊断光束质量研究

 为了解决高功率激光装置光束质量诊断系统的自验证问题，研究了基于空间相位调制的径向剪切干涉法综合诊断光束质量的实验应用。该方法理论上只需一台干涉仪且从单幅干涉图中获取光束的近场、相位和远场分布信息。实验结果表明，目前可以得到高分辨率的相位分布，由测量近场和相位恢复出的远场同CCD直接测量得到的远场形态相同，环围能量比曲线相当吻合，不足之处在于只能提取近场较低空间频率成分，还达不到CCD直接测量的空间分辨水平。     

Viscometric properties of dilute polystyrene/dioctyl phthalate solutions

We report viscometric data collected in a Couette rheometry on dilute, single‐solvent polystyrene (PS)/dioctyl phthalate (DOP) solutions over a variety of polymer molecular weights (5.5 × 10⁵ ≤ M_w ≤ 3.0 × 10⁶ Da) and system temperatures (288 K ≤ T ≤ 318 K). In view of the essential viscometric features, the current data may be classified into three categories: The first concerns all the investigated solutions at low shear rates, where the solution properties are found to agree excellently with the Zimm model predictions. The second includes all sample solutions, except for high‐molecular‐weight PS samples (M_w ≥ 2.0 × 10⁶ Da), where excellent time–temperature superposition is observed for the steady‐state polymer viscosity at constant polymer molecular weights. No similar superposition applies at a constant temperature but varied polymer molecular weights, however. The third appears to be characteristic of dilute high‐molecular‐weight polymer solutions, for which the effects of temperature on the viscosity curve are further complicated at high shear rates. The implications concerning the relative importance of hydrodynamic interactions, segmental interactions, and chain extensibility with increasing polymer molecular weight, system temperature, and shear rate are discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 787–794, 2006     

考虑材料熔化潜热的高温高压本构

本文在修正的SCG模型基础上，提出了一种考虑了熔化潜热的高温高压本构.该本构所给出的铝的剪切模量的变化分为三个阶段：加工硬化，温度软化和熔化，并在完全熔化点处变为零.并且在前两个阶段，计算的结果与修正的SCG模型所给出的剪切模量的差别不超过4%，这一差别是在动高压实验误差范围之内的，在熔化区所给出的剪切模量与现有的实验数据相符合. 关键词： 剪切模量 熔化潜热 修正的SCG模型 动高压实验