焓差法空调制冷量测量不确定度分析

介绍了焓差法空调测试系统及测量原理,分析了焓差法空调测试过程中各个量的不确定度来源以及评定方法,并以实验数据为基础,对具体的实验数据进行了分析计算。提出了减小焓差法空调测试系统测量不确定度的途径,以提高测量的准确性和测量数据的可信度。     

Analysis of Faraday–Michelson quantum key distribution system with unbalanced attenuation

Quantum key distribution(QKD) is a major research topic because it provides unconditional security. Unfortunately, many imperfections remain in QKD's experimental realization. The Faraday–Michelson(FM) QKD system is proposed to eliminate these imperfections using polarization. However, the long arm's phase modulator(PM) has an unexpected insertion loss, meaning that the state sent is no longer perfect. In this letter, we propose an alternative FM-QKD system structure, and analyze the security and key generation rate in comparison with the original system via different analysis methods. We find an obvious key rate improvement when the PM insertion loss is not extremely small.     

Simple and practical method of characterizing the parametric down-conversion source

Parametric down-conversion(PDC) sources play an important role in quantum information processing, therefore characterizing their properties is necessary. Here we present a statistical model to assess the properties of the PDC source with certain distribution, such as the brightness and photon channel transmissions, we only need to measure the singles and coincidences counts in a few seconds. Furthermore, we validate the model by applying it to a PDC source generating highly non-degenerate photon pairs. The results of the experiment indicate that our method is more simple, efficient, and less time consuming.     

Experimental Decoy State Quantum Key Distribution Over 120km Fibre

Decoy state quantum key distribution （QKD）, being capable of beating PNS attack and being unconditionally secure has become attractive recently. However, in many QKD systems, disturbances of transmission channel make the quantum bit error rate （QBER） increase, which limits both security distance and key bit rate of real-world decoy state QKD systems. We demonstrate the two-intensity decoy QKD with a one-way Faraday- Michelson phase modulation system, which is free of channel disturbance and keeps an interference fringe visibility （99%） long period, over a 120 km single mode optical fibre in telecom （1550nm） wavelength. This is the longest distance fibre decoy state QKD system based on the two-intensity protocol.     

表面等离子激元波的光学二次谐波效应及应用 Ⅱ.表面吸附分子的非线性效应的研究

在表面等离子激元波(SPW)激发条件下,研究了吸附L-B单分子膜层的银表面反射二次谐波(SHG)的增强效应,理论分析与实验结果一致,并估算出吸附的单个花生酸分子的非线性系数为0.32E-29esu。     

基于雪崩级联电路控制激光照明源的水下激光选通成像

基于雪崩级联原理研发了用于水下激光选通成像的MARX级联电路激光照明源。相对于普通激光驱动器,该MARX级联电路有输出脉冲窄、峰值高、上升沿短、重复频率高、成本低、体积小、质量轻等优点。采用级联电路研发的脉冲激光照明光源在实现ns量级脉冲宽度性能的基础上保持了照光源系统体积的小型化。该脉冲照明源结合激光整形及匀化光学技术进行了水下选通成像验证实验,在10 ns的脉冲宽度下,实现水下7倍衰减长度范围内的选通成像。该文涉及的电路、光学方面的改进对降低激光选通成像系统的体积、成本及实际应用具有重要意义。     

双大环配体与铜双核配合物的合成、晶体结构和磁偶合性质

由新型双功能配体2,6-双(1,5,9-三氮杂环十二烷)-2,6-二甲基苯甲酸(L)与溴化铜在甲醇中反应得到新型铜双核配合物[Cu~2LBr~2]Br.3H~2O单晶。晶体结构分析表明:2个Cu(II)中心离子由配体L中的羧酸基团桥联;2个等价的Cu(II)中心离子均由双功能配体L的1,5,9-三氮杂环十二烷([12aneN~3)的3个氮原子和羧酸的1个氧原子及1个Br^-离子配位,并都处在三角双锥的配位环境中;分子内Cu...Cu双核间的距离为0.5884(6)nm。变温磁化率数据表明:在同一分子中的2个铜核之间存在反铁磁偶合作用(J=-22.49cm^-^1)。     

Fast implementation of length-adaptive privacy amplification in quantum key distribution

Post-processing is indispensable in quantum key distribution(QKD), which is aimed at sharing secret keys between two distant parties. It mainly consists of key reconciliation and privacy amplification, which is used for sharing the same keys and for distilling unconditional secret keys. In this paper, we focus on speeding up the privacy amplification process by choosing a simple multiplicative universal class of hash functions. By constructing an optimal multiplication algorithm based on four basic multiplication algorithms, we give a fast software implementation of length-adaptive privacy amplification. "Length-adaptive" indicates that the implementation of privacy amplification automatically adapts to different lengths of input blocks. When the lengths of the input blocks are 1 Mbit and 10 Mbit, the speed of privacy amplification can be as fast as 14.86 Mbps and 10.88 Mbps, respectively. Thus, it is practical for GHz or even higher repetition frequency QKD systems.     

Adjustable unbalanced quantum random-number generator

We report an adjustable unbalanced quantum random-number generator based on the polarization of photons,which can produce nondeterministic true random unbalanced numbers. The underlying physical process is inherently quantum mechanical. To prove the quality of the output sequence of the proposed generator, we test the obtained bias-free sequence through the 3-standard-deviation criteria and the National Institutes of Standards and Technology test suite. Another type of nondeterministic unbalanced random-number generator is also studied in this work, to evaluate the quality of the output biased random numbers.     

MCM-22型分子筛的合成及其用于生产异丙苯的催化性能

MCM-22 molecular sieve was first reported by Rubin et al[1] in Mobil Company.Similar to ZSM-5 zeolite, MCM-22 belongs to the category of medium pore zeolites.However, it possesses unique structural features[2] that have not been demonstrated before. The structure of MCM-22 was resolved by Mobil scientists using high resolution microscopy and X-ray diffraction analysis. It is found that MCM-22 consists of two independent and non-interconnecting channel systems, each accessible through 10-ring apertures. One of these pore systems is composed of uniform circular 10-ring pores about 0.6 nm. The other is composed of 12-ring egg-shaped supercages with inner free diameter of 0.71 nm and inner height of 1.82 nm. Usually the zeolite crystallizes as thin sheets or plates of stocked layers. Therefore, MCM-22 has been actively studied and this peculiar zeolite may have potential applications in the petrochemical and petroleum industries in the near future, including reactions such as disproportionation[3], catalytic cracking of hydrocarbons[4], aromatic/ethylene alkylation[5], isoalkane/olefins[6] and methanol/olefins alkylation[7] etc.