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851.
Hong-Wei Sun Long Zhang Hui-Juan Zuo Ke-Jia Zhang Chun-Guang Ma 《International Journal of Theoretical Physics》2018,57(9):2695-2708
In this paper, we present an offline arbitrated quantum blind dual-signature protocol by using four-particle entangled Greenberger-Horne-Zeilinger(GHZ) states. By using the special relationship of four-particle GHZ states, we can not only support the security of quantum signature, but also guarantee the anonymity of the message owner. In our protocol, the authority of the arbitrator has been reduced, i.e., he will not help the receiver verify the signature in the verification. Compared with the previous quantum blind signature protocols, the presented arbitrator is offline. Finally, the security analysis and discussion are proposed. 相似文献
852.
853.
正With the impressive progress of flat panel display technologies,the three-dimensional(3D)display and imaging technologies have attracted much attention in recent years as they can provide ultimate realistic views to us.Hence we designed a focus issue intended to introduce recent optical researches in this field,especially the works by some distinguished research groups. 相似文献
854.
855.
采取标准锌显色剂与锌发生显色反应,生成不溶于水的絮状络合物。用光谱仪测它的吸光度,研究其特征谱与吸光度的特点,建立其浓度与特征波长吸光度间的数学模型。本文所采用的显色剂主要与锌、铜、镉、镍四种离子发生络合反应。因此分别探索了四种离子高浓度以及低浓度时显色反应的吸光度,最终通过得到锌离子浓度与吸光度的关系式以及锌离子浓度与四波长下四种离子混合溶液显色后的吸光度的关系式,给出了锌离子的吸光度与总吸光度的关系式。显色反应能否满足分光光度法的要求,主要与显色剂的性质有关,同时显色反应的条件也至关重要。因为在显色反应过程中,主要是锌离子与锌显色剂发生络合反应形成络离子,进而形成絮状络合物。络离子一般比较稳定,但在水溶液中也存在着电离平衡,也就是说当显色条件发生变化时,既有可能形成络离子,也有可能发生络离子的分解,从而影响络合反应的程度。显色条件包括显色剂用量、pH值、反应温度、显色时间、待测溶液的盐度以及浊度等。重点研究待测溶液的盐度对锌离子浓度测量值的影响,并通过实验给出影响规律以及校正模型。 相似文献
856.
Chen He Ban‐Kun Jin Wei‐Dong He Xue‐Song Ge Jing Tao Jing Yang Sheng‐Qi Chen 《Journal of polymer science. Part A, Polymer chemistry》2013,51(10):2142-2149
Long‐subchain hyperbranched polystyrene (lsc‐hp PSt) with uniform subchain length was obtained through copper‐catalyzed azide‐alkyne cycloaddition click chemistry from seesaw macromonomer of PSt having one alkynyl group anchored at the chain centre and two azido group attached to both chain ends [alkynyl‐(PSt‐N3)2]. After precipitation fraction, different portions of lsc‐hp PSt having narrow overall molecular weight distribution were obtained for further grafting with alkynyl‐capped poly(N‐isopropylacrylamide) (alkynyl‐PNIPAM), which was obtained via single‐electron transfer living radical polymerization of NIPAM with propargyl 2‐bromoisobutyrate as the initiator and grafted onto the peripheral azido groups of lsc‐hp PSt via click chemistry. Thus, amphiphilic lsc‐hp PSt grafted with PNIPAM chains (lsc‐hp PSt‐g‐PNIPAM) was obtained and would have star‐like conformation in tetrahydrofuran (THF). By replacing THF with water, lsc‐hp PSt‐g‐PNIPAM was dissolved at molecular level in aqueous solution due to the hydrophilicity of PNIPAM and exhibited thermal induced shrinkage of PNIPAM arms. The water‐insoluble lsc‐hp PSt would collapse densely and could be served as a reservoir to absorb hydrophobic chemicals in aqueous solution. The influence of overall molecular weight of lsc‐hp PSt on the absorption of pyrene was studied. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
857.
Huiyun Wu Xin Li Shen Sheng Zhisong Huang Shuhai Huang Siqing Zhao Hua Wang Zhenhai Sun Xiegu Xu Rui Xiao 《Optik》2013
Model of an optical system with coherent laser array source and the piston phase optimized by the stochastic parallel gradient descent algorithm is established. With this model, theory of beam propagation through the optical system in turbulent atmosphere is analyzed, and the analytical formulas of the beam average intensity along the propagation path are derived. Strehl ratio of the received beam induced by intensity disorderly distribution and power efficiency of the received beam are introduced to evaluate performance of the optical system. Under the H-V 5/7 atmospheric turbulent model, performance of an optical system with determinate parameters was calculated, and the influences of the propagation distance and the laser wavelength were numerically analyzed, respectively. 相似文献
858.
859.
Based on the actual competition in the Chinese property insurance market, the repeated price game model for four oligarchs with different decision rules is built. On the basis of analyzing the stabilities of eight fixed points about the four-dimensional dynamic system, the Nash equilibrium and its local stable region are discussed mainly. Then the complexity of the four-dimensional discrete dynamic system and its evolutionary process are studied. Finally, the delay feedback control method is used to control the chaos. Numerical simulation results have shown that the influence which the change of price adjustment speed has on the movement of dynamic system has a sensitive dependence on the initial conditions, and there is a strong connection between the profit of each oligarch and the price adjustment speed or the control parameters, and the corresponding economic explanation to those phenomena will have important reference values to the realistic problems. 相似文献
860.
Henry reaction is one of the most classical reactions to construct synthetically useful product nitro alcohol, which as a privileged skeleton is widely distributed in various pharmaceuticals. This review summarizes the recent progress of copper-catalyzed asymmetric Henry reaction from 2011 to 2016. The significant progress that has been made in this area will be highlighted and some of challenges that the author believes may be hindering further progress will be revealed. 相似文献