热退火γ-Al2O3/Si异质结构薄膜质量改进

采用高真空MOCVD外延技术,利用TMA(Al(CH3)3)和O2作为反应源,在Si(100)衬底上外延生长γ-Al2O3绝缘膜形成γ-Al2O3/Si异质结构材料.同时,引入外延后退火工艺以便改善γ-Al2O3薄膜的晶体质量及电学性能.测试结果表明,通过在O2常压下的退火工艺可以有效地消除γ-Al2O3外延层的残余热应力及孪晶缺陷,改善外延层的晶体质量,同时可以提高MOS电容的抗击穿能力,降低漏电电流.     

地市级农信业务网络系统安全解决方案

信息加密的目的是保护网内的数据、文件、口令和控制信息不被窃取,保护网上传输的数据不被窃取和修改。网络加密常用的方法有链路加密和端到端加密。链路加密的目的是保护网络节点之间的链路信息安全;端     

两种介质柱构成复式正方晶格的完全光子带隙

由一个正方介质柱和两个圆介质柱构造一个二维正方复式晶格的光子晶体.应用平面波展开的方法研究了光波在其中的传播规律.通过调节介质柱几何尺寸和介电常数,该结构产生了完全光子带隙.     

Si掺杂的AlGaInP/GaInP多量子阱光学特性

低压MOCVD方法生长了掺Si与不掺Si的AlGaInP/GaInP多量子阱结构,运用X射线双晶衍射与光荧光技术研究了掺Si对量子阱性能的影响.测试结果表明掺Si使量子阱的生长速度增加,掺Si量子阱的光荧光强度比未掺Si量子阱的光荧光强度改善了一个数量级.     

探测波导全息光栅傅里叶变换光谱的新方法

提出一种利用波导全息光栅分光元件 ,通过测量波导光栅附近区干涉条纹 ,经快速傅里叶变换达到测量光谱的新方法。讨论了波长测量范围和光谱分辨率。给出了在设计波导光栅、确定探测器时应该考虑的几个问题。对系统测量误差进行了分析。该光谱探测方法具有光谱分辨率高、波长范围宽和结构简单等优点。     

Experimental optimization of an erbium-doped super-fluorescent fiber source for fiber optic gyroscopes

Double-pass forward and double-pass backward erbium-doped super-fluorescent fiber sources(EDSFSs) were combined in one configuration.A 980 nm laser diode pumped the same erbium-doped fiber from both directions using a coupler as a power splitter.The double-pass configuration was achieved by coating the fiber end face.Firstly,an optimal fiber length was found to obtain a high stability of output light wavelength with pump power, and then 1530/1550 nm wavelength division multiplexing was used for spectrum planarization,which expanded the bandwidth to more than 22 nm.The final step was a test of temperature stability.The results show that the rate of the central wavelength change kept to below 3.5 ppm/℃in the range of -40 to 60℃and 1-2 ppm/℃in the range of 20-30℃.Considering all the three factors of the fiber optic gyro applications,we selected 80 mA as the pump current,in which case the central wavelength temperature instability was calculated as 2.70 ppm/℃, 3 dB bandwidth 22.85 nm,spectral flatness 0.2 dB,output power 5.17 mW and power efficiency up to 9.92%.This experimental result has a significant reference value to the selection of devices and proper design of ED-SFSs for the application of high-precision fiber optic gyroscopes.     

氦—氖激光血管内照射治疗脑梗塞疗效观察与机制探讨

目的：探讨低能量He-Ne激光血管风照射治疗脑梗塞的疗效。方法：将144例脑梗塞患者附机分为实验组和对照组,各72例,实验组采用低能量He-Ne激光血管内照射治疗,同时结合药物治疗,对照组仅给予药物治疗。结果：实验组和对照组总有效率分别是91.67%和75％,两组疗效显著（P＜0.05）。结论：低能量He-Ne激光血管内照射治疗脑梗塞疗效显著,安全可靠,无付作用。     

A nonlinear optical loop mirror-based linear cavity swit- chable multi-wavelength erbium-doped fiber laser

A nonlinear optical loop mirror (NOLM)-based linear cavity switchable multi-wavelength erbium-doped fiber (EDF) laser is proposed and experimentally demonstrated. Due to the characteristics of the intensity-dependent transmissivity, the NOLM can effectively mitigate the mode competition of the homogenous broadening gain medium, so that the multi-wavelength lasing can be achieved at room temperature. By adjusting the states of the polarization controllers (PCs), the number of the lasing wavelengths in the proposed laser can be adjusted flexibly from 11 to 13 with a wavelength spacing of 0.4 nm around the wavelength of 1 530 nm.     

国产无甲醛抗水剂诞生

无甲醛抗水剂是一种新型抗水剂。其性能和使用效果都优于常规的氨基树脂抗水剂,其特点是:可以用于各种胶粘剂的涂料配方中;用量仅为氨基树脂的二分之一,纸厂使用成本略低于氨基树脂抗水剂;固化迅速,成纸下机后就有抗湿摩擦效果,不需熟化;存放时水溶性