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71.
72.
We propose a novel scheme for measurement-device-independent (MDI) continuous-variable quantum key distribution (CVQKD) by simultaneously conducting classical communication and QKD, which is called “simultaneous MDI-CVQKD” protocol. In such protocol, each sender (Alice, Bob) can superimpose random numbers for QKD on classical information by taking advantage of the same weak coherent pulse and an untrusted third party (Charlie) decodes it by using the same coherent detectors, which could be appealing in practice due to that multiple purposes can be realized by employing only single communication system. What is more, the proposed protocol is MDI, which is immune to all possible side-channel attacks on practical detectors. Security results illustrate that the simultaneous MDI-CVQKD protocol can secure against arbitrary collective attacks. In addition, we employ phasesensitive optical amplifiers to compensate the imperfection existing in practical detectors. With this technology, even common practical detectors can be used for detection through choosing a suitable optical amplifier gain. Furthermore, we also take the finite-size effect into consideration and show that the whole raw keys can be taken advantage of to generate the final secret key instead of sacrificing part of them for parameter estimation. Therefore, an enhanced performance of the simultaneous MDI-CVQKD protocol can be obtained in finite-size regime. 相似文献
73.
采用多步法依次将制备的Fe3O4纳米颗粒和Pt纳米颗粒负载到多壁碳纳米管(MCNT)上得到Pt/Fe3O4-MCNT磁性催化剂,以X射线衍射(XRD)、透射电镜(TEM)、超导量子干涉磁强计(SQUID)和热重-差热分析(TG-DTA)对Pt/Fe3O4-MCNT磁性催化剂的结构和磁性质进行了表征。研究发现预制备的Fe3O4纳米颗粒与Pt纳米颗粒均匀地分散于MCNT上,新制备以及多次使用后的Pt/Fe3O4-MCNT室温下都具有良好的超顺磁性。研究了Pt/Fe3O4-MCNT磁性催化剂上的肉桂醛选择性加氢反应,结果显示催化剂具有良好的C=O加氢活性,肉桂醛转化率在50%左右时,肉桂醇选择性可达96%以上。尺寸均一的Pt粒子均匀的分散在催化剂上可能是催化剂具有良好的C=O加氢选择性的重要原因。在外加磁场作用下催化剂可以高效地从液相反应体系中分离,经多次循环使用后仍具有良好的催化性能。 相似文献
74.
75.
纳米铜修饰玻碳电极的制备及其对葡萄糖的催化氧化 总被引:2,自引:1,他引:2
在表面活性剂十六烷基三甲基溴化铵(CTMAB)的分散作用下,通过恒电位还原CuSO4在玻碳电极上沉积Cu,得到纳米Cu修饰玻碳电极(nano-Cu-GCE),该修饰电极对葡萄糖(Glu)的氧化具有明显的催化作用,利用该催化作用对Glu进行检测,通过研究沉积电位、沉积时间以及检测电位对电流信号的影响,优化了电极的制备条件和Glu的检测条件。沉积电位为-100mV,沉积时间8min。在检测电位400mV下,Glu在1.0×10-6~3.9×10-4mol/L范围内Glu电流与空白溶液电流值之差与其浓度呈线性关系,检出限为2.6×10-7mol/L(S/N=3),线性回归方程Δi(μA)=-1.02-125674.54C(mol/L),r=0.9981。抗坏血酸(AA)、对乙酰氨基酚(AP)和L-半胱氨酸(Cys)对Glu信号几乎无干扰。 相似文献
76.
77.
CdS nanowires-nitrogen doped graphene(CdS NWs-NGR) nanocomposites have been fabricated by an electrostatic self-assembly strategy followed by a hydrothermal reduction. The CdS NWs-NGR exhibits higher photoactivity for selective reduction of aromatic nitro organics in water under visible light irradiation than blank CdS nanowires(CdS NWs) and CdS nanowires-reduced graphene oxide(CdS NWs-RGO)nanocomposites. The enhanced photoactivity of CdS NWs-NGR can be attributed to the improved electronic conductivity due to the introduction of nitrogen atoms, which thus enhances the separation and transfer of charge carriers photogenerated from CdS NWs.Our work could provide a facile method to synthesize NGR based one-dimensional(1D) semiconductor composites for selective organic transformations, and broaden the potential applications for NGR as a cocatalyst. 相似文献
78.
79.
Ying-Ying Chen Yi-Jun Jiang Yan-Sen Fan Di Sha Qifeng Wang Guangliang Zhang Liangyu Zheng Suoqin Zhang 《Tetrahedron: Asymmetry》2012,23(11-12):904-909
A double axially chiral bisphosphorylimide has been demonstrated to be an efficient and highly sterically hindered Brønsted acid in asymmetric three-component Mannich reactions. Optically active syn-β-amino ketones were obtained in high yields (up to 99%) with excellent diastereoselectivity (99:1) and enantioselectivity (up to 99% ee). A gram-scale reaction was also performed to prove the synthetic application value of this reaction. 相似文献
80.
Lian HZ Kang YF Yasin A Bi SP Shao DL Chen YJ Dai LM Tian LC 《Journal of chromatography. A》2003,993(1-2):179-185
Morin was used as a pre-column reagent for the determination of aluminum by RP-HPLC with fluorescence detection. This method has been successfully applied to direct determination of trace Al in environmental and biological samples. The response was linear from 6 x 10(-9) to 6 x 10(-5) M with a detection limit of 2 x 10(-9) M. In addition, the different Al complexes with morin were separated by the proposed HPLC procedure and their coordination ratios were depicted by molar-ratio method. The results showed that 1:1 and 2:1 Al-morin complexes formed. 相似文献