Ion-beam analysis of the structure and composition of nanocomposite nc-TiC/a-C:H coatings

The structure and composition of nanocomposite nc-TiC/a-C:H thin films prepared by closed-field unbalanced reactive magnetron sputtering in an argon-acetylene atmosphere have been investigated. The concentrations of carbon and heavier elements have been obtained by Rutherford backscattering and nuclear backscattering. The hydrogen concentration in the films has been determined by elastic recoil detection analysis. Based on the data obtained, a scheme has been proposed to evaluate the C:H matrix mass density and the sp ³ and sp ² fractions in the matrix.     

C60醛类衍生物非线性光学特性研究

研究了加合不同取代基团的C60醛类衍生物的光学非线性性质。利用简并四波混频（DFMW）方法获得了C60醛类各衍生物的三阶光学非线性超级化率γ^(3)及相应的三阶光学非线性系数χ^(3)值。同时也研究了它们各自的光限幅特性。结果表明：不同的取代基对C60醛类衍生物三阶光学非线性及光限幅特性的影响不同。     

Cd3Al2Ge3O12:Mn2+锗酸盐石榴石光谱性质

本文报道室温下Cd₃Al₂Ge₃O₁₂:Mn²⁺(简称CAGG:Mn²⁺)锗酸盐石榴石的漫反射光谱、激发和发射光谱.在UV光激发下,在CAGG中Mn²⁺离子发射强黄光,这是基质到Mn²⁺离子无辐射能量传递的结果.Mn²⁺的黄发射带是由一个弱的红带和一个强的绿带所组成.讨论了这两个Mn²⁺发射带的起因.     

A Generalized Quasilinearization Method for Nonlinear Second-Order Impulsive Differential Equations Involving the <Emphasis Type="Italic">p</Emphasis>-Laplacian

Using variational method and lower and upper solutions, we get a generalized quasilinearization method which construct an iterative scheme converging uniformly to a solution of a nonlinear second-order impulsive differential equations involving the p-Laplacian, and converging quadratically when p=2.     

光纤机敏结构制作方法的研究

本文讨论机敏结构的制作方法、集成光纤传感器存在的问题、现有解决方法和今后的研究方向。     

返波型行波电子直线加速结构的理论研究

比较了行波与驻波两种工作方式以及前向波与返波型行波的不同特点;研究了返波型行波电子直线加速结构的工作特性;并针对返波型行波电子直线加速结构的特点,进行工作模式的选择;对工作频率为2856MHz,3π/4模的返波加速结构进行了优化设计;研究了带聚束段的返波型行波加速管的纵向与横向粒子动力学问题;为海关大型集装箱在线检测用加速器设计了一根9MeV返波型行波加速管,并与采用盘荷波导结构的加速管进行了对比.研究结果表明,返波型行波电子直线加速结构具有一定的优势,它把鼻锥型加速结构分流阻抗高及盘荷波导行波工作方式填充时间短,工作稳定性好等优点结合起来,性能明显优越.     

High intensity focused ultrasound-induced gene activation in solid tumors

In this work, the activation of heat-sensitive trans-gene by high-intensity focused ultrasound (HIFU) in a tumor model was investigated. 4T1 cancer cells (2 x 10(6)) were inoculated subcutaneously in the hind limbs of Balb/C mice. The tumors were subsequently transducted on day 10 by intratumoral injection of a heat-sensitive adenovirus vector (Adeno-hsp70B-Luc at 2 x 10(8) pfu/tumor). On day 11, the tumors were heated to a peak temperature of 55, 65, 75, or 85 degrees C within 10-30 s at multiple sites around the center of the tumor by a 1.1- or 3.3-MHz HIFU transducer. Inducible luciferase gene expression was increased from 15-fold to 120-fold of the control group following 1.1-MHz HIFU exposure. Maximum gene activation (120-fold) was produced at a peak temperature of 65-75 degrees C one day following HIFU exposure and decayed to baseline within 7 days. HIFU-induced gene activation (75 degrees C-10 s) could be further improved by using a 3.3-MHz transducer and a dense scan strategy to 170-fold. Thermal stress, rather than nonthermal mechanical stress, was identified as the primary physical mechanism for HIFU-induced gene activation in vivo. Overall, these observations open up the possibility for combining HIFU thermal ablation with heat-regulated gene therapy for cancer treatment.     

WDM网状网中动态域间流量疏导策略

对波分复用(Wavelength Division Multiplexing,WDM)网状网中的动态域间流量疏导问题进行了深入研究.在源路由模式下,提出了一种基于固定备选路由方式的动态域间流量疏导算法,并在其基础上提出了只考虑波长均衡和同时考虑波长均衡与业务均衡的改进方法.该算法可以有效地避免路由环,得到较低的阻塞率,节省全网的收发器数目和波长资源.仿真结果表明,这种算法可以有效地改善网络性能.     

基于边缘软判决的小波域自适应图像去噪

提出了一个新的图像去噪方法。该方法基于非抽样小波变换的多分辨分解,在各尺度下对小波系数进行了边缘和非边缘分类,并根据它们的不同统计特性运用了不同的估计技术。鉴于边缘分类的不确定性,提出了依概率的软分类技术,通过计算边缘发生的概率,判决当前系数应该采用哪一种估计。仿真结果表明:该方法在滤除图像噪声的同时,边缘得到了保持,较目前存在的一些方法更具有优越性。