A simple dynamic integrated provisioning/protection scheme in IPover WDM networks

This article presents a simple integrated provisioning/protection scheme to dynamically allocate restorable bandwidth guaranteed paths in IP over WDM networks. A guaranteed restorable path implies that a flow of data is successfully routed if both an active path and another alternate link-disjoint path are found at the same time. Unlike the conventional approach, where the IP and WDM layers are not aware of each other, the new scheme takes advantage of the development in generalized multi-protocol label switching (GMPLS) to provide integrated end-to-end survivability by incorporating network state information from both layers (e.g., the cost information in physical links, the bandwidth usage on each lightpath, and intermediate router speed) into protection path allocation. Simulation results are used to evaluate the performance of the new scheme and show that the proposed protection approach can efficiently improve the network utilization, and deliver reliable services     

推荐一类贴近生活的基础分析化学综合实验——食品中钙、镁、铁含量测定

介绍一类基础分析化学综合实验,其内容贴近生活,可操作性强,实验经费少。通过实验,学生不仅可以了解日常食物中Ca、Mg、Fe的含量,而且可将理论与实践、学与用结合起来。     

水中丙溴磷的富集及气相色谱分析

采用ＧＤＸ－５０１吸附剂富集水中痕量丙溴磷,然后用气相色谱法直接测定,方法简便、准确,实用。水中丙溴磷的检出限为０．４μｇ／Ｌ,低、中、高３种浓度的平均加标回收率为８８．６％－９９．３％,相对标准偏差在３．２３％－４．９６％范围内。     

时谐LC电路的量子效应

根据Lewis-Risenfeld的量子不变量理论,研究了时谐LC电路的量子效应。结果显示:由于电路参数随时间变化,在含时相干态下LC电路中电荷和电流量子涨落的不确定度乘积不可能达到最小值h^-2/4。     

钛宝石泵浦的Yb:YAG晶体的激光性能

测量了Yb:YAG晶体的光谱特性,用Ar⁺离子泵浦钛宝石激光器作为泵浦源泵浦Yb:YAG晶体,采用平平腔设计,当输出耦合镜T_1.053μm=4.26%,泵浦功率为1410mW时,得到320mW1.053μm的高效CW激光输出,斜率效率为54%,外推阈值功率为203mW。     

脑梗塞的He—Ne激光血管内照射治疗的信息生物学分析

脑梗塞患者血浆cAMP水平比对照组低,可以应用高剂量He-Ne激光血管内照射和药物联合使用提高cAMP的水平,达到改善血液流变学特性、提高细胞免疫功能和清热解毒的效果。本文应用刘承宜等人提出的低强度激光的生物信息假说总结了有关方面的基础与临床研究,阐述了低强度激光治疗脑梗塞的细胞机理,为临床应用提供了理论依据。     

低强度氦氖激光调整红细胞变形性的机理研究

目的红细胞变形能力对于微循环血流的维持起着至关重要的作用.细胞和临床研究表明,低强度He-Ne激光可以调整红细胞的变形性.本文根据刘承宜等人提出的低强度激光的生物信息假说来研究低强度激光对红细胞变形性的调整机制.     

Ti:Sapphire Pumped 10 at-% Yb:YAG Thin Chip with 320 mW CW laser output of 1.053 μm

We have developed an efficient room-temperature 10 at-% Yb:YAG thin chip (7 mm×7 mm×1 mm) laser operating at 1.053 μm pumped by a Ti-sapphire laser operating at 940 nm. 320 mW of output power was obtained for an absorbed pump power of 791 mW. The slope efficiency was 54%, and extrapolated threshold power was 203 mW.     

Ti:sapphire Laser Pumped Yb:YAG Laser with Cr4+:YAG as a Passive Q-switch

The Ti: sapphire laser pumped Yb: YAG passively- Q- switched laser with Cr4 +: YAG as a saturable absorber experiment was performed. The Mira 900 tunable Ti:sapphire laser with an output power up to 1 W was used as a pump source. The optical pump system was composed of a spherical lens (f = 75 mm) for focusing the pump beam to a circular spot with a diameter of about 50μm, the pumping power was measured to be up to 920 mW. The laser cavity was configured to be semispherical, and was formed by the 50 mm curvature radius mirror Mi and the flat mirror M2. Mirror Mt, one face was coated for high transmission at 940 nm and the other face was coated for total reflection at 940 nm and 1.03 μm, was placed on the front of the input facet of the Yb: YAG crystal. The Yb: YAG gain medium is doped with 20 at. - ％ Yb3+, no concentration quenching of the upper-state lifetime has been observed in this crystal. The Yb: YAG gain element is 8 × 8 × 0.5 mm3 thick and is polished flat and paralld. It is coated on one face of the crystal for high transmission at 940 nm and at 1030 nm, the other surface of the crystal is coated for total reflection at 940 nm and at 1030 nm. Mirror M2 was coated for total reflection at 940 nm and reflectivity of 97％ at 1.03 μm acting as an output coupler. The overal cavity length is 23 cm. More than 90％ of the laser pumping power was absorbed by the Yb: YAG crystal. The laser operation was performed at 278 K by using the constant-temperature water-cooled circulation with a copper surface. The Cr4+: YAG saturable absorber was placed tightly dose to Yb: YAG sample. This provided a train of pulsesat 1.03 μm with a pulse duration (FWHM) decreasing from 0.6 μs to 0.4 μs and a repetition rate increasing from 20 kHz to 50 kHz. The maximum average power of 53 mW is attained when the pmping power is 730 mW. The slope efficiency is about 16％.     

含源电路在压缩真空态的激发态下的量子涨落

分析了含源RLC电路中的复哈密顿量,在压缩真空态的激发态下求解了电荷和电流的量子涨落,并对结果进行了讨论。