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891.
Lou TJ Zeng JH Lou XD Fu HL Wang YF Ma RL Tong LJ Chen YL 《Journal of colloid and interface science》2007,314(2):510-513
Sphere- and rod-shaped Zn(2)SiO(4):Mn(2+) phosphor nanocrystals were synthesized at 230 degrees C. The process consists of tuning the surfactant concentration in the oil/surfactant/ethanol system. Powder X-ray (XRD) and transmission electron microscopy (TEM) were used to characterize the phase purity, size and morphology. Photoluminescent (PL) spectra were collected and analyzed. Fourier transform infrared (FT-IR) spectra of the samples indicate the removal of surfactant in the phosphor nanoparticles. As a result, the sphere-shaped phosphor nanoparticles of 100 nm in size can be redispersed in ethanol ultrasonically. The suspension maintain stable for over 48 h. 相似文献
892.
One of the major difficulties faced in the molecular imprinting of proteins is the inherently fragile and flexible nature of the protein template which makes it incompatible with most polymerization systems. Miniemulsion polymerization is a possible approach for preparing molecularly imprinted nanoparticles, and in this study, the method of initiation, the high-shear homogenization, and the surfactant used for the polymerization reaction had been considered as possible factors that can denature the template protein, ribonuclease A (RNase A). The conformation of the protein in a miniemulsion was studied using circular dichroism (CD). It was found that redox initiation was more suitable for protein imprinting and that the addition of poly(vinyl alcohol) (PVA) as a co-surfactant had proved to be effective in preserving the template protein structural integrity. On the basis of the results of the study, polymeric nanoparticles imprinted with RNase A were prepared via miniemulsion polymerization using methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) as the functional and cross-linker monomers, respectively, with the conditions of the polymerization system optimized to best preserve the integrity of the protein template. In the subsequent investigation for the recognition properties of the prepared nanoparticles through batch and competitive rebinding tests, the imprinted nanoparticles prepared through the conventional (nonoptimized) miniemulsion polymerization lacked the target specificity as displayed by those prepared under the optimized conditions. This illustrated the importance of protein structural integrity in protein imprinting. 相似文献
893.
894.
1 Introduction Thefiberdevicesbasedonfiberfusednullcouplerarerecentlyofgreatinterest.All fiberacousto opticswitch[1] ,tunableopticalfilter[2 ] ,opticaladd dropmultiplexer (OADM ) [3] andfiberpolarizer[4 ] havebeenreported .Foralltheseapplications ,nullcouplerwithlow… 相似文献
895.
研究了PVB单分子膜的π~A曲线和稳定性,沉积了优质LB膜,发现将PVB与CdSt2形成交替异质的LB膜能提高膜的光学质量;在CdSt2LB膜的上面封装PVBLB膜能保持CdSt2LB膜的结构。 相似文献
896.
基于栅控脉冲发射X射线源与单光子探测技术的X射线通信已经实现了实验室语音通信验证,并对通信系统的误码率性能进行了分析,为探索未来X射线深空应用打下了坚实的基础.针对目前X射线通信面临的信号发散角大、通信距离短、难以实现工程化应用的情况,迫切需要对X射线通信天线系统进行深入研究.为了提高信号增益、增大X射线通信的距离,提出了多层嵌套式X射线聚焦光学作为X射线通信的"收发天线",理论分析了X射线聚焦光学用于X射线通信"收发天线"的可行性,分析了X射线聚焦光学的理论基础与结构设计,对"发射天线"发散角、"接收天线"有效面积与焦斑尺寸、信号增益等性能做了探讨.结果表明:在信号发射端,"天线"的发散角为3 mrad左右,发射增益23 d B;在信号接收端,"接收天线"的有效面积5700 mm2@1.5 keV,焦斑直径为4.5 mm,接收增益为25 d B,通信系统总的增益可达48 d B. 相似文献
897.
898.
Tang Chuanxiang Lin Yuzheng Tong Dechun Wu Yuanming Wang Youzhi Zhao Xinqiao Xie Jialin 《中国物理C(英文版)》1997,21(4):378-383
Thi spaper describes thedesign,simulation and experiment of a multi-cavity RF gun with thermionic cathode for BFEL.This RF gun consists of 1/2+3 cavities (its first half cavity is about 1/3 of a full cavity) with a axis coupling bi-period standing-wave accelerating structure,and works at π/2 mode,2856MHz.We shortened the length of the lst cavity and added a short drift between the 2nd and 3rd cavities,so that the power of back bombardment electrons was greatly decreased and the logitudinal properties were adjusted properly. 相似文献
899.
900.