基于NS2的OBS网络仿真平台研究与实现

给出了一种基于NS-2的OBS网络仿真平台--OBS-NP(OBS-NS2-platform).该平台通过扩展NS-2中的节点类与链路类,支持对光突发交换(OBS)网络的运行及关键算法的仿真.在详细描述OBS-NP系统构成的基础上,以一个9节点OBS网络为基础,对网络中突发包的时延、吞吐量和资源利用率进行了仿真,并给出了突发包的路由信息.最后,对OBS-NP仿真结果的准确性进行了分析和讨论.     

云安21井127mm超短尾管固井技术

云安21井是川东开发公司在云安厂红家湾潜伏构造上的一口超深开发井,该井设计井深为5709m;实钻过程中钻遇断层,导致井深增加,实际井深钻达5858．00m,裸跟井段73．00m,属于典型的“深井、小尺寸、短尾管”固井范畴。介绍了该井的固井技术难点,固井技术措施、水泥浆体系的优选、现场应用及认识与体会。     

Microwave active resonator band-pass filters in various mmic technologies

In this article, two topologies of L-C parallel active resonators are presented. These circuits are realized in MMIC technology, using three transistors which could be MESFET, hemt or HBT. The survey of these resonators shows the possibility, by controling the values of a resistor and/or a capacitor, on the one hand, to tune the resonance frequency of these circuits, and on the other hand, to cancel out their losses so as to obtain negative conductance. Compact, lossless and narrow-band filters are then implemented using previous active resonators. To date, the use of mesfet technology has reduced the synthesis of such active filters in S-band and at X-band low frequencies. Now, however, hemt and HBT technologies allow the extension of their implementation to the whole X-band. This survey is illustrated by the simulated response of a 10 GHz filter with a 500 MHz 3 dB bandwidth. The mmic technology is a 0.2 μm hemt one. The simulated performances of this filter achieve a mean transmission gain of 0. 5 dB, with a reflection loss higher than 10 dB at 10 GHz,     

基于分布式应变的三芯光纤形态重构算法研究

为了利用分布式光纤传感技术测量的光纤应变进行三芯光纤三维形态重构,设计 了重构算法, 并利用有限元求解数据进行了验证。首先,设计了三芯光纤曲率和弯曲方向采样值的计算方 法,利用三次 样条插值法构建了曲率和挠率连续函数,基于Frenet-Serret框架设计了弧长参数下的空间 曲线公式;然后 构建了三芯光纤有限元模型,求解并提取了单向弯曲和S形弯曲的光纤应变分布数据,并带 入设计的算法 中进行求解,实现了三芯光纤的三维形态重构;最后通过均方根误差和归一化准确度对重构 误差进行了计 算和分析。结果表明,设计的三芯光纤三维形态重构算法误差控制在0.07%以内。该算法还原效果好,精度高,具有一定的理论和工程应用价值。     

电视机的虚拟开发与设计（一）--电子元器件的虚拟开发设计

本文主要应用虚拟技术对电视机进行开发,在设计和开发过程中,主要对电视机的基本结构如电视机外壳、电子元器件、连接导线和PCB等结构要素进行交互操作、场景开发和动画控制,给出了详细的开发过程和开发效果图,对于电视机的开发具有一定的借鉴作用。     

IP over WDM网络中一种新型虚拓扑构造算法

对IP over WDM的虚拓扑设计算法进行了研究，选择网络整体流量的均衡性作为优化目标，提出了一种新型的虚拓扑构造算法。在算法中，选择负载分布方差作为评价流量均衡性的指标，并给出其定义和计算方法。主要针对拥塞概率性能，在光层和IP层将提出的新型虚拓扑构造算法与其他算法进行比较。在光层的算法比较部分，选择负载均衡启发式路由算法（RLBH，routing with load balancing heuristics）与提出的算法进行比较；在IP层的算法比较部分，选择固定路径最小拥塞路由算法（FPLC，fixed-path least-congestion）与提出的算法进行比较，并对比较结果进行了讨论。比较结果显示在拥塞概率性能方面，提出的新型虚拓扑构造算法优于RLBH算法和FPLC算法。     

Flavor Constituents of Aqueous Fraction Extracted from Comte Cheese by Liquid Carbon Dioxide

Isolation, purification and identification of some low-molecular-weight compounds from a water-soluble extract of Comté cheese was achieved. We used liquid CO₂ extraction, subsequent fractionation (by gel permeation and reserve-phase HPLC) and mass spectometry. Major constituents were N-acyl amino acids (N-acetyl methionine, N-propionyl methionine, N-propionyl leucine, N-propionyl phenylalanine), dike-topiperazines (cyclo(Pro-Pro), cyclo(Pro-Val), cyclo(Pro-Phe), cy clo(Pro-Leu), cyclo(Pro-Ala)) and non-peptide compounds (theo-bromine, 4-methyl-t-thiazoleethanol, uracil, (5–6)dihydro-uracil, thymine). These compounds were synthesized and tasted. Most were bitter. N-propionyl methionine had a cheese flavor but was not detected when added to a simulated cheese at 180 mg/L.     

Bacterial Growth and Volatile Compounds in Yoghurt-Type Products from Soymilk Containing Bifidobacterium ssp

The growth of bacteria normally used to produce yoghurt was compared in soymilk and cow milk. Whether or not Bifidobacterium ssp. was present, fermented soymilks [soyoghurt (S), soyoghurt + bifi-dobacteria (SB)] were less acidic than fermented cow milks [yoghurt (Y), yoghurt + bifidobacteria (YB)]. When bifidobacteria were present (in SB), streptococci were more numerous than lactobacilli. Bifidobacteria in YB stimulated maximal growth of both yoghurt bacteria. In comparison to nonfermented milks, acetaldehyde and diacetyl increased in all cultures. Ethanol increased only in S/SB and acetone was detected only in Y/YB. Quantities of volatile products in Y/'YB were slightly lower than those in Y/S. In all cultures, n-hexanal was almost totally absent.     

有源阵列天线的发展及应用

介绍了有源阵列天线的发展概况、组成结构及技术特点,并对比其与无源阵列天线的优缺点,讨论了有源阵列天线的应用及发展前景。     

扩容优化CDMA网短信平台提升业务性能

江西电信CDMA 2000网络的短信业务量及业务种类的迅速增长,对短信平台业务处理能力提出了更高要求。通过新增短信平台调度中心,增强各调度中心处理能力,实现了平台业务能力扩容;不同类型短信业务分流至不同调度中心的优化策略,实现了短信业务的QoS保障。2009年运营数据表明,平台扩容及策略优化,确保了短信平台能力满足业务发展需求,并对重要业务实施了QoS保障,提升了短信业务性能。