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71.
ZHANG Zai-xuan WANG Jian-feng LIU Hong-lin XU Hai-fen DAI Bi-zhi LI Chen-xia LI Lan-xiao GENG Dan INSOO S. KIM 《光电子快报》2007,3(6)
A 31 km long range distributed optical fiber Raman photon temperature sensor (DOFRPTS) system have been developed based on temperature effect of the amplified spontaneous Raman scattering in fiber, and using fiber laser as a pumped source. The results show that temperature measuring uncertainty is ±2 ℃, temperature resolution is 0.1 ℃, measurement time is 432 s, spatial resolution is less than 4 m. 相似文献
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To increase battery life in IEEE 802.16e systems, it is essential to efficiently manage energy in mobile stations. The sleep-mode operation in power management helps to increase the life of a station by saving energy consumption. In power management, there are two important performance metrics energy consumption and the response delay of awakening medium access control (MAC) service data unit (SDU). While in a base station (BS) initiation of awakening, the two performance metrics should be simultaneously considered, in a mobile subscriber station (MSS) initiation of awakening, the response delay is not considered because it is self-operational. There performance metrics are affected by the minimum sleep interval (Tmin), the maximum sleep interval (Tmax), and the average interarrival time of awakening MAC SDUs (TI) during sleep-mode operation. Therefore, it is imperative to evaluate the two initiations of awakening depending on TI. To reach a fuller understanding of the performance, this paper shows an analytical mode and simulations results for the standard sleep-mode operation in the IEEE 802.16e MAC. 相似文献
74.
In-Soo SON Sang-Pill LEE Jin-Kyung LEE Woo-Cheol KIM Ji-Seon MOON Sangmok LEE Jong-Sup LEE Yong-Bae KIM Geun-Ahn LEE Dong-Su BAE 《中国有色金属学会会刊》2014,(Z1):75-80
研究液压对混合复合铸造Al 3003/Al 4004包覆材料微观组织变化的影响。复合铸造Al 3003/Al 4004包覆材料试样为圆形,由Al 3003(外部)和Al 4004(内部)材料组成。采用液压设备,在温度423 K、挤压比5的条件下制造试样。在挤压之前,Al 4004材料的直径为80 mm,Al 3003材料的厚度为35 mm,在挤压后,2种材料的直径和厚度分别为30 mm和5 mm。研究了2个试样的微观组织和硬度。在挤压之前,复合铸造Al 3003/Al 4004包覆材料横截面的硬度以抛物线的形式向中心增大。然而,在挤压后,Al 4004材料的硬度几乎没有变化。在挤压之前,Al 3003和Al 4004材料的界面存在大量直径超过1 mm的大空洞,这些大空洞随着液压过程的进行而消失。 相似文献
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Kyo-Hong CHOI Kwon-Koo CHO Gyu-Bong CHO Hyo-Jun AHN Ki-Won KIM Yoo-Young KIM 《材料科学与工程学报》2007,25(6):886-891
Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD. 相似文献
78.
开发高效、稳定、廉价的钙钛矿氧化物电极材料是固体氧化物燃料电池(SOFC)进一步商业化发展的关键。目前,研究重点仍集中在解决阳极积碳、硫毒化以及阴极氧还原(ORR)低温性能不佳等问题。最近,有研究报道,一些易还原过渡金属元素掺杂的钙钛矿可以在还原气氛中原位析出该金属并以纳米颗粒的形式"镶嵌"在钙钛矿表面形成"纳米金属–钙钛矿"复合结构。该方法制备的材料具有性能高、抗积碳能力强、可再生性好等优点。从钙钛矿氧化物本体的选择、A/B位掺杂、缺陷调整、以及拓扑离子交换、相变诱发等方面,总结了近年来关于构建纳米(析出金属颗粒)微米(钙钛矿氧化物母体)异质结构(统称纳微异构)钙钛矿氧化物纳米纤维复合电极的研究。此外,总结了具有纳米纤维状形貌的钙钛矿氧化物电极及其结构对于SOFC性能、稳定性的影响,最后提出了该类纳微异构材料的优势、不足和展望。 相似文献
79.
KWANG-HOON KONG SUNG-GUAN HONG SUN-YOUNG YOO KWANG-SOO LEE HA-HYUNG KIM 《Journal of Food Biochemistry》2004,28(6):500-512
A lectin gene homolog of Oryza sativa was successfully cloned and expressed in Escherichia coli. The deduced amino acid sequence of the protein product showed a significant similarity with known chitin‐binding lectins. Most of the recombinant lectin was found in an insoluble aggregated form as inclusion bodies and only a small part was in the culture medium in a soluble active form. Functional recombinant lectin was recovered from the inclusion bodies by solubilization with 8 M urea in Tris/HCl buffer, pH 7.0 and renaturation by 10‐fold dilution in the same buffer. The recombinant lectin with His‐tag was simply purified to homogeneity by the process of affinity chromatography and was obtained with a yield of 6–8 mg/L culture. The recombinant lectin was a homo‐dimer composed of 22 kDa. The hemagglutination activity of the recombinant lectin was optimal at pH 4.0–7.0 and it was very sensitive to inhibition by N‐acetylneuraminic acid and thyroglobulin. 相似文献
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