一种稳定的自由空间量子密钥分配实验系统

基于量子密钥分配的基本原理,采用B92方案,以单光子作为信息载体,使用极化编码,搭建了一个简单易行的实验装置,实现了自由空间传输的量子密钥分配,平均每脉冲光子数为0．1,粗码率12．7kbits／s,误码率4％左右。     

Pseudoreceptor model for ryanodine derivatives at calcium release channels

This paper describes the generation of a pseudoreceptor model for ryanodine receptor (RyR) modulating ryanoids in rabbit skeletal muscle. For this purpose, the molecular modelling software PrGen was applied to correlate experimentally determined and calculated free energies of binding for a set of 15 ryanodine derivatives. The final model indicates a narrow cleft with hydrogen bond donor and acceptor capacities (represented by an Asn) as most crucial for binding the pyrrole carboxylate substituent at C3 of ryanodine. In addition, hydrophobic residues flank the aromatic pyrrole ring (Tyr, Phe, and Ile). Two of those residues (Tyr and Ile) interact with the 2-isopropyl moiety, which seems to contribute to binding. Opposite to the pyrrole locus, a second hydrophobic region (represented by a Leu) restricts ryanodine derivatives in their longitudinal axis and leads to the discrimination of equatorial and axial positioned methyl groups and of polar substituents at C9. Finally, a charged glutamate residue generates strong hydrogen bonding and electrostatic interactions with the hydroxyl groups at C10 and C15. For this binding-site model – composed of six amino acid residues – a correlation for the training set ligands of R = 0.99 (Q² = 0.975) and a root mean square (rms) deviation of 0.568 kcal/mol for the prediction of the binding energies of four test set ligands was obtained. Based on this pseudoreceptor model the putative topology of the real binding site of ryanoids will be discussed.     

非线性左手材料中的二次谐波

基于电磁场理论，推导了无耗非线性左手材料中二次谐波的曼利－诺关系，及相位匹配条件下正向基波与逆向二次谐波的能量转换过程及其空间分布.验证了可将无耗非线性左手材料的入射面作为反射镜，把能量以二次谐波的形式反射.同时分别给出有限厚度介质板中基波和二次谐波的场强分布数值结果，验证了结论的正确性.最后从相位失配角度说明了相位匹配是分析非线性左手材料二次谐波的重要条件.这为研究左手材料的非线性理论奠定了基础.     

Multi-agent controlled teleportation of multi-qubit quantum information via two-step protocol

Utilizing both the general quantum teleportation and the two-step protocol, a new method is presented by which multi-qubit quantum information can be teleported in a much easier way from a sender Alice to a receiver Bob via the control of many agents in a network than by Yang et al＇s method. In this method, only all the agents collaborate with Bob can the unknown states in Alice＇s qubits be fully reconstructed in Bob＇s qubits. Comparisons between the method and Yang et al＇s method are made. Results show that, in this method, the preparation difficulty of initial states and the identification difficulty of entangled states are considerably reduced, new method is more feasible in technique, and Hadamard operations are not needed at all.     

Consensus problems on networks with free protocol

In the real world, rule makers can only restrict, not completely control the behavior of the governed, while the governed can only choose their behavior patterns under these restrictions. In this paper, we design a new control protocol called free protocol to describe this situation. First, we calculate consensus probabilities based on the information of the interaction networks. Then, sufficient conditions are obtained for all agents converging to a same value with probability one. Finally, numerical simulation results are given to verify the above results.     

“On water” ultrasound-assisted one pot efficient synthesis of functionalized 2-oxo-benzo[1,4]oxazines: First application to the synthesis of anticancer indole alkaloid,Cephalandole A

For the first time, an efficient, simple, synthetic green protocol for the one-pot synthesis of functionalized 2-oxo-benzo[1,4]oxazines 24–29 in water under ultrasound irradiation is presented. As compared to conventional methods, the present protocol avoids traditional chromatography and purification steps and furnished the target molecules in excellent yields (upto 98%) with no side products. The methodology was also demonstrated on gram scale synthesis. Moreover, functionalized 2-oxo-quinoxaline analogues 31–33, another class of bio-active heterocyclic scaffolds, were also prepared using this method. For the first time, this protocol was successfully applied in the synthesis of the anticancer indole alkaloid, Cephalandole A 35.     

Development of a headspace-gas chromatography (HS-GC-PID-FID) method for the determination of VOCs in environmental aqueous matrices: Optimization, verification and elimination of matrix effect and VOC distribution on the Fortaleza Coast, Brazil

An analytical protocol combining a headspace technique with gas chromatography and detection by photoionization detector and flame ionization detector (HS-GC-PID-FID) was developed. This procedure was used to measure volatile organic compounds (VOCs) in environmental aqueous matrices and was applied in determination of VOCs on the coast of Fortaleza, Brazil. At optimum operating conditions, analytical figures of merit such as linearity (R ranged from 0.9983 to 0.9993), repeatability (5.62 to 9.63% and 0.02 to 0.19% for the quantitative and qualitative analyses, respectively), detection limits (0.22 to 7.48 μg L⁻¹) and sensibility were estimated. This protocol favors a fast sampling/sample preparation (in situ), minimizes the use of laboratory material, eliminates the matrix effect from environmental samples, and can be applied to river, estuarine and oceanic waters. The advantage of detectors in series is that a low sensitivity in detection in one is compensated by the other. Toluene was the most abundant VOC in the studied area, with an average concentration of 1.63 μg L⁻¹. It was followed by o-xylene (1.15 μg L⁻¹), trichloroethene (1.08 μg L⁻¹), benzene (0.86 μg L⁻¹), ethylbenzene (0.74 μg L⁻¹), carbon tetrachloride (0.55 μg L⁻¹), m/p-xylene (0.48 μg L⁻¹) and tetrachloroethene (0.46 μg L⁻¹), compounds which are very commonly detected in urban runoff from most cities. The results of the VOC distribution showed that port activity was not the main source of VOCs along the Fortaleza Coast, but that the contribution from urban runoff seemed more significant.     

基于BiB3O6晶体的飞秒光参量变换特性

对基于新型非线性晶体BiB₃O₆(BIBO)的飞秒光参量变换过程的参量特性进行了研究. 计算了BIBO晶体三个光学主平面内的相位匹配条件和有效非线性系数,确定了克尔透镜锁模钛宝石激光器的基频光与倍频光抽运时最佳的光学主平面和相位匹配方式,并分析了三波的时间走离和空间走离,以及信号光的参量增益和带宽. 为利用基于BIBO晶体的飞秒光参量技术获得高能量、宽调谐、窄脉宽的光源提供理论依据和实验指导. 关键词： 3O₆')" href="#">BiB₃O₆ 光参量变换 共线相位匹配 光学主平面     

Quantum anonymous voting with anonymity check

We propose a new protocol for quantum anonymous voting having serious advantages over the existing protocols: it protects both the voters from a curious tallyman and all the participants from a dishonest voter in unconditional way. The central idea of the protocol is that the ballots are given back to the voters after the voting process, which gives a possibility for two voters to check the anonymity of the vote counting process by preparing a special entangled state of two ballots. Any attempt of cheating from the side of the tallyman results in destroying the entanglement, which can be detected by the voters.     

基于电力线载波与TCP/IP协议的刚体转动惯量实验系统的设计

介绍了一种新的测量刚体转动惯量的实验方法与实验装置,在实验中,通过增加标准刚体试件,把细线拉力对转轴摩擦力矩的影响考虑进去,大幅度地提高了实验测试精度,另外,利用电力线载波通讯网络,将转动惯量测量仪采集的时间数据传输到PC机中,再经过PC机端数据处理软件,快速准确地将待测刚体的转动惯量以及其它与刚体有关的物理量计算、显...