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91.
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Cooperative relaying is considered as an effective technique to enlarge the coverage area and enhance the system capacity for the future wireless systems. In this paper, an infrastructure based multi-antenna cooperative relay network has been investigated. Closed form expressions of outage probability and average error rate have been derived, when the relay and the destination perform selection combining of the signals. The relay is assumed to operate in the adaptive decode and forward mode. The effect of number of antennas installed on the relay and their placement has also been studied. 相似文献
93.
A new fluorescence probe, CdSe nanocrystal has been prepared and modified with 11-mercaptoundecanoic acid [HS-(CH2)10-COOH]. The functionalized nanoparticles were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy. The results demonstrate that CdSe is dispersed homogeneously in aqueous solution and well protected from the environmental oxygen. They can be used as a new fluorescence probe for lysozyme, which was simple, rapid and specific. Under the optimum condition, the response is linearly proportional to the amount of lysozyme from 0.20 to 26.0 μg ml−1, and the limit of detection is 0.115 μg ml−1. The proposed method has been applied to the determination of lysozyme in egg white, with the recovery of 96-105%. 相似文献
94.
Yanfei Zhou Zhaoyang Shen Xiaojun Huang Jiong Wu Yujun Li Siqi Huang Helin Yang 《Physics letters. A》2019,383(23):2739-2743
The natural water has frequency dispersion and its permittivity is also related to temperature, which are important factors to design temperature insensitive absorber at microwave frequency. Here, a water-based metamaterial absorber which is fabricated by 3D-printing is proposed. The absorber can perform stably at different temperatures and it also shows 90% absorption in the frequency range of 7.9–21.7 GHz. The experiment proves that the absorber can work at a wide incident angle and is polarization insensitive. Based on these features, the water-based absorber could be applied to various electromagnetic scenarios such as stealth technology and electromagnetic compatibility in temperature-variable environment. 相似文献
95.
以介孔聚多巴胺(MPDA)的制备为出发点,通过搭载化疗药物阿霉素(DOX)和包覆相变材料 1-十四醇(PCM),构建了 pH/光热双重响应的 MPDA-DOX@PCM 纳米递送系统,实现了对耐药膀胱癌细胞(BIU-87/ADR)的光热治疗(PTT)和化疗。结果表明,MPDA-DOX@PCM 尺寸约为 179 nm,DOX的最大搭载率为 22%,光热转换效率高达 49.1%。在 pH=7.4和温度为 25 ℃的条件下,DOX的累积释放率为4.57%;当pH值降为5.5和温度升高到45 ℃时,DOX的累积释放率可提高到60.13%。在808 nm激光辐照下,MPDA-DOX@PCM孵育的BIU-87/ADR细胞存活率降低至9.5%,证明了其优异的PTT/化疗联合治疗性能。 相似文献
96.
Zhaoyang Zhang Xinxin Xue Chuangshe Li Sijing Cheng Lei Han Haixia Chen Huaibin Zheng Yanpeng Zhang 《Optics Communications》2012,285(17):3627-3630
We demonstrate the coexisting four-wave mixing (FWM) signal and six-wave mixing (SWM) signal which can be enhanced both by electromagnetically induced transparency (EIT) and optical pumping effect in a common three-level and open four-level inverted-Y type systems of 85Rb. We also analyze the effect of optical pumping in different energy level systems by arranging laser beams and comparing the strength of the increased and reduced absorption caused by optical pumping. 相似文献
97.
Zhaoyang Cheng Shipei Xing Jun Guo Biao Cheng Lan‐Fang Hu Xing‐Hong Zhang Zhan Lu 《中国化学》2019,37(5):421-421
The cover picture shows that sequential 1,1‐dihydrosilylation of terminal aliphatic alkynes with primary silanes enabled by one earth‐abundant cobalt catalyst has been developed. This protocol is operationally simple using readily available aliphatic alkynes, including simple acetylene and complex drug derivative, for efficient access to valuable gem‐bis(dihydrosilyl)alkanes in highly regioselective and atom‐economic manners. Corresponding asymmetric transformations are achieved with excellent enantioselectivities. More details are discussed in the article by Lu et al. on page 457–461.
98.
We reported the morphology-directed synthesis of Co(3)O(4) nanotubes via interfacial reaction of NaOH with pre-fabricated CoC(2)O(4)·2H(2)O nanorods based on modified Kirkendall effect. The as-obtained Co(3)O(4) nanotubes showed excellent activity and durability in catalytic combustion of CH(4). 相似文献
99.
100.