InSb芯片碎裂与迸溅金点的关系

批量生产中经常发生的锑化铟(InSb)芯片碎裂问题制约着InSb红外焦平面探测器(IRFPAs)成品率的提升.经分析认为:低周期液氮冲击下发生在器件边沿区域的InSb芯片破碎与该区域中迸溅金点的存在有关.为从理论上明晰迸溅金点对InSb芯片局部碎裂的影响,本文建立了包含迸溅金点的InSb IRFPAs结构模型,分析了迸...     

二次曲面非球面度计算方法及公式

本文用分析、对比的方法简要叙述了计算非球面度过去沿用公式存在的缺陷,特别是在工艺方面的不适用性,根据实际工艺提出了新的计算方法和公式,并进行了推导。利用这些公式既能准确表达非球面度的概念,也可直接用于指导生产加工。     

Turbulence-induced changes in degree of polarization, degree of coherence and spectrum of partially coherent electromagnetic beams

Based on a recently formulated unified theory of coherence and polarization, a method is described to study turbulence-induced changes in the polarization, the coherence and the spectrum of partially coherent electromagnetic beams on propagation. The electromagnetic Gaussian Schell-model beam is taken as a typical example of partially coherent electromagnetic beams, and the closed-form expressions for the degree of polarization, the degree of coherence and the spectrum of electromagnetic Gaussian Schell-model beams propagating through atmospheric turbulence are derived in the quadratic approximation of Rytov's phase structure function. Some interesting results are obtained, which are illustrated by numerical examples and are explained in physics.     

基于灰色关联分析的医学图像分割

医学图像分割处理为临床诊断、病理分析、治疗提供可靠的依据。为了分割出图像中感兴趣的区域,提出了一种基于灰色理论区域生长分割算法。该方法利用灰色关联理论对图像进行关联性分析,根据像素间全局和局部的关联度,指导区域生长的分割和停止。该方法的最大不同之处在利用灰色理论进行关联性分析,不需要大量数据的统计,算法简单,高效。实验证明,该方法能够有效地分割出目标区域,并且具有一定的抗噪能力,是一种较为有效的图像分割新方法。     

Investigation on properties of P((MAA-co-DMAEMA)-g-EG) polyampholyte nanogels

P((MAA-co-DMAEMA)-g-EG) polyampholyte nanogels (PANGs) were prepared by distillation-dispersion copolymerization of poly(ethylene glycol) methyl ether methacrylate (MPEGMA), N,N-dimethylaminoethyl methacrylate (DMAEMA), and methacrylic acid (MAA) using acetonitrile (AN) as dispersion medium. The results of FTIR spectra indicate that the composition of P((MAA-co-DMAEMA)-g-EG) PANGs is consistent with the designed structure. The results of TEM and laser particle size analyzer (LPSA) show that P((MAA-co-DMAEMA)-g-EG) PANGs present spherical morphology and a bimodal size distribution after and before swelling. P((MAA-co-DMAEMA)-g-EG) PANGs have typically amphoteric characters responding to pH, whose isoelectric point (IEP) increases with decreasing the ratio of MAA/DMAEMA and equilibrium swelling degree (ESD) is greater than that at IEP when the pH value is distant from IEP. P((MAA-co-DMAEMA)-g-EG) PANGs also represent ionic strength sensitivity. Using the water-soluble chitosan (CS, Mn = 5 kDa) as model drug, in vitro release indicates that CS can be effectively incorporated into PANGs and the release rate of CS at pH 1.89 is an order of magnitude greater than that at pH 8.36. P((MAA-co-DMAEMA)-g-EG) PANGs may be useful in biomedicine, especially in oral drug delivery of biomacromolecule.     

不同调制方式下偏振度与偏振模色散的关系

给出了偏振度与偏振模色散关系的理论模型,分析了非归零和归零两种调制方式下的偏振度与偏振模色散关系特性,结果表明偏振度町以作为实时检测偏振模色散的信号;且偏振度对偏振模色散的有效检测范围不大于调制光信号的占空比α,同时检测灵敏度与有效检测范围成反比;在非归零调制时偏振度对偏振模色散的有效检测范围最宽,为调制光信号的一个调制周期,是常规归零调制(占空比为0．5)时的2倍,但灵敏度只有常规归零调制时的一半。进一步探讨了在实际应用中改善偏振度对偏振模色散的有效检测范围和灵敏度的方法。实验验证了非归零调制时偏振度与偏振模色散关系特性。     

激发对相干态的等阶Y压缩效应

用数值计算法研究了激发对相干态|ζ;m〉＝a^+mb^+m|ζ〉的等阶Y压缩效应.结果表明:对于态a^+mb^+m|ζ〉,光场存在着等阶K(＝2,3,4,5,…)次方Y压缩效应,但是随着场模上光子增加数m的增大,等阶K次方Y压缩效应减弱.     

Structural polarization properties of vector Gaussian beam in the far field

Based on the vector angular spectrum representation of optical beam and the method of stationary phase, the analytical TE and TM terms of vector Gaussian beam have been presented in the far field. By using the local polarization matrix, the polarization properties of the TE and TM terms in the far field are investigated, and it is found that the degree of their polarization is only determined by the spatial location. When the source is completely polarized, the TE and TM terms are both completely polarized in the far field. When the source is completely unpolarized, the TE and TM terms in the far field are partially polarized. The whole beam is also partially polarized except on the propagating axis. Moreover, the degrees of polarization of TE and TM terms are both larger than that of the whole beam.[第一段]     

Matrix assisted pulsed laser evaporation of poly(d,l-lactide) thin films for controlled-release drug systems

We report the successful deposition of the porous polymer poly(d,l-lactide) by matrix assisted pulsed laser evaporation (MAPLE) using a KrF* excimer laser (248 nm, τ = 7 ns) operated at 2 Hz repetition rate. The chemical structure of the starting materials was preserved in the resulting thin films. Fluence played a key role in optimizing our depositions of the polymer. We demonstrated MAPLE was able to improve current approaches to grow high quality thin films of poly(d,l-lactide), including a porosity control highly required in targeted drug delivery.     

The polarization property and irradiance distribution of incoherent and coherent Gaussian beam combinations

Based on the beam coherence-polarization (BCP) matrix, the polarization property of coherent and incoherent Gaussian beam combinations is studied in detail. The general expressions for the degree of polarization P of the resulting beam in case of incoherent and coherent combinations are derived. It is shown that P is dependent on the incoherent or coherent combination, propagation distance, separation, azimuth of the polarization plane and numbers of beamlets in general. The irradiance distribution of the resulting beam for the coherent cases depends on the azimuth of the polarization plane of beamlets. However, for the incoherent case it does not.