锂二次电池中的原位聚合电解质

聚合物电解质主要分为凝胶聚合物电解质和固态聚合物电解质两种类型,均能够提升锂二次电池的性能。其中,凝胶聚合物电解质是利用增塑剂实现聚合物基质的凝胶化,将有机液态电解液固定在三维网络结构中,因此同时具备液态的离子扩散速率和固态材料的机械性能;而固态聚合物电解质是一种完全没有液态电解质的体系,利用聚合物基体的极性实现锂盐的解离,以聚合物分子链的运动实现离子传输。相对于传统的非原位法制备的聚合物电解质而言,原位聚合反应制备的聚合电解质能够有效改善电解质与电极的界面相容性、简化电池组装工艺、降低制造成本。本文综述了当前原位聚合电解质在锂二次电池中应用的研究进展,并展望了原位聚合电解质的应用前景和未来挑战。     

Parameter estimation of continuous variable quantum key distribution system via artificial neural networks

Continuous-variable quantum key distribution(CVQKD)allows legitimate parties to extract and exchange secret keys.However,the tradeoff between the secret key rate and the accuracy of parameter estimation still around the present CVQKD system.In this paper,we suggest an approach for parameter estimation of the CVQKD system via artificial neural networks(ANN),which can be merged in post-processing with less additional devices.The ANN-based training scheme,enables key prediction without exposing any raw key.Experimental results show that the error between the predicted values and the true ones is in a reasonable range.The CVQKD system can be improved in terms of the secret key rate and the parameter estimation,which involves less additional devices than the traditional CVQKD system.     

Multi-polar resistance switching and memory effect in copper phthalocyanine junctions

Copper phthalocyanine junctions, fabricated by magnetron sputtering and evaporating methods, show multi-polar （unipolar and bipolar） resistance switching and the memory effect. The multi-polar resistance switching has not been observed simultaneously in one organic material before. With both electrodes being cobalt, the unipolar resistance switching is universal. The high resistance state is switched to the low resistance state when the bias reaches the set voltage. Generally, the set voltage increases with the thickness of copper phthalocyanine and decreases with increasing dwell time of bias. Moreover, the low resistance state could be switched to the high resistance state by absorbing the phonon energy. The stability of the low resistance state could be tuned by different electrodes. In Au/copper phthalocyanine/Co system, the low resistance state is far more stable, and the bipolar resistance switching is found. Temperature dependence of electrical transport measurements demonstrates that there are no obvious differences in the electrical transport mechanism before and after the resistance switching. They fit quite well with Mott variable range hopping theory. The effect of A1203 on the resistance switching is excluded by control experiments. The holes trapping and detrapping in copper phthalocyanine layer are responsible for the resistance switching, and the interfacial effect between electrodes and copper phthalocyanine layer affects the memory effect.     

基于光前置放大器的量子密钥分发融合经典通信方案

量子密钥分发融合经典通信方案将连续变量量子密钥分发和经典通信合并到了一起,为将来在现有的光网络上同时进行密钥分发和经典通信提供了一个有效的方法.然而,在量子信号上叠加一个经典信号将会给连续变量量子密钥分发系统引入过噪声从而大大降低系统的性能.本文提出基于光前置放大器的量子密钥分发融合经典通信方案,即在接收端插入光前置放大器来提升系统的性能.首先,在相同比特误码率条件下,光前置放大器对信号的放大能够降低对发送端经典信号调制振幅的要求,从而降低经典信号对量子信号的噪声影响;其次,光前置放大器能够补偿接收端探测器的不完美;再次,对于本地本振光的情形,放大器还能放大弱相位参考脉冲,从而降低参考脉冲散粒噪声带来的相位过噪声.在实际可达到的系统参数下,数值仿真结果表明本文提出的方案相比于原方案在安全密钥率和传输距离上都有很好的提升.这些结果表明本方案为量子密钥分发融合经典通信方案的进一步发展和实际应用提供了一个十分有效而实用的方法.     

一种新型金属配合物的非线性光学特性的研究

利用单光束Z扫描技术，在波长532nm、脉宽8ns的条件下研究了新型的金属有机配合物ECuCl2（BOEP）2]的三阶非线性光学性质。由实验结果发现配位化合物虽然没有明显的非线性吸收性质，但是其三阶非线性折射率比相应配体大很多。探讨了配合物的结构和其三阶非线性光学性质的关系，认为配位化合物的丌共轭离域体系的增大和金属中心离子与配体之间的电子转移是配合物具有更大非线性折射率的主要原因。选择具有π键的配体与金属离子合成为配合物，使其非线性效应明显增强，这对合成性能更好的非线性材料有一定的参考价值。     

Spin-independent transparency of pure spin current at normal/ferromagnetic metal interface

The spin transparency at the normal/ferromagnetic metal(NM/FM) interface was studied in Pt/YIG/Cu/FM multilayers. The spin current generated by the spin Hall effect(SHE) in Pt flows into Cu/FM due to magnetic insulator YIG blocking charge current and transmitting spin current via the magnon current. Therefore, the nonlocal voltage induced by an inverse spin Hall effect(ISHE) in FM can be detected. With the magnetization of FM parallel or antiparallel to the spin polarization of pure spin currents(σ(sc)), the spin-independent nonlocal voltage is induced. This indicates that the spin transparency at the Cu/FM interface is spin-independent, which demonstrates that the influence of spin-dependent electrochemical potential due to spin accumulation on the interfacial spin transparency is negligible. Furthermore, a larger spin Hall angle of Fe_(20)Ni_(80) (Py) than that of Ni is obtained from the nonlocal voltage measurements.     

基于量子催化的离散调制连续变量量子密钥分发

相比于离散变量量子密钥分发,连续变量量子密钥分发虽然具备更高的安全码率等优势,但是在安全传输距离上却略有不足.尽管量子催化的运用对高斯调制连续变量量子密钥分发协议的性能,尤其在安全传输距离方面有着显著的提升,然而能否用来改善离散调制协议的性能却仍然未知.鉴于上述分析,本文提出了一种基于量子催化的离散调制协议的方案,试图在安全密钥率、安全传输距离和最大可容忍过噪声方面进一步提升协议性能.研究结果表明,在相同参数下,当优化量子催化引入的透射率T,相比于原始四态调制协议,所提方案能够有效地提升量子密钥分发的性能.特别是,对于可容忍过噪声为0.002,量子催化可将安全通信距离突破300 km,密钥率为10^-8bits/pulse,而过大的可容忍噪声会抑制量子催化对协议性能的改善效果.此外,为了彰显量子催化的优势,本文给出了点对点量子通信的最终极限Pirandola-Laurenza-Ottaviani-Banchi边界,仿真结果表明,虽然原始方案与所提方案都未能突破这种边界,但是相比于前者,后者能够在远距离通信上逼近于这种边界,这为实现全球量子安全通信的最终目标提供理论依据.     

High-performance synaptic transistors for neuromorphic computing

The further development of traditional von Neumann-architecture computers is limited by the breaking of Moore’s law and the von Neumann bottleneck, which make them unsuitable for future high-performance artificial intelligence (AI)systems. Therefore, new computing paradigms are desperately needed. Inspired by the human brain, neuromorphic computing is proposed to realize AI while reducing power consumption. As one of the basic hardware units for neuromorphic computing, artificial synapses have recently aroused worldwide research interests. Among various electronic devices that mimic biological synapses, synaptic transistors show promising properties, such as the ability to perform signal transmission and learning simultaneously, allowing dynamic spatiotemporal information processing applications. In this article, we provide a review of recent advances in electrolyte-and ferroelectric-gated synaptic transistors. Their structures, materials,working mechanisms, advantages, and disadvantages will be presented. In addition, the challenges of developing advanced synaptic transistors are discussed.     

快速康复外科在肝癌肝切除术中的应用及对细胞免疫功能的影响

目的探讨快速康复外科（FTS）在肝癌肝切除患者围术期的临床应用效果及对细胞免疫功能的影响。方法选取择期行肝癌肝切除术患者48例,按随机数字表法分为FTS组与常规组,各24例,比较两组患者术后肝功能、细胞免疫功能及临床疗效指标。结果两组患者临床基线资料比较差异均无统计学意义（均P＞0.05）。术后第３天,FTS组TBil为（113.96±61.39）μmol/L,ALT为（146.17±72.51）U/L,AST为（155.04±54.04）U/L;常规组TBil为（165.25±64.38）μmol/L,ALT为（213.46±107.48）U/L,AST为（225.92±81.51）U/L,两组比较差异均有统计学意义（均P＜0.05）;FTS组CD3+、CD4+、CD4+/CD8+指标均明显优于常规组（均P＜0.05）。FTS组患者术后首次肛门排气时间、首次进半流质时间、首次排便时间均较常规组提前（均P＜0.05）,术后住院时间亦缩短（P＜0.05）。结论FTS理念用于肝癌肝切除术患者围术期处理可降低患者术后应激反应、提高术后细胞免疫功能,改善患者术后肝功能恢复效果、缩短术后肛门排气时间和住院时间,安全性好,加快患者康复,值得临床应用。     

Short-wave infrared continuous-variable quantum key distribution over satellite-to-submarine channels

The trans-media transmission of quantum pulse is one of means of free-space transmission which can be applied in continuous-variable quantum key distribution (CVQKD) system. In traditional implementations for atmospheric channels, the 1500-to-1600-nm pulse is regarded as an ideal quantum pulse carrier. However, the underwater transmission of this pulses tends to suffer from severe attenuation, which inevitably deteriorates the security of the whole CVQKD system. In this paper, we propose an alternative scheme for implementations of CVQKD over satellite-to-submarine channels. We estimate the parameters of the trans-media channels, involving atmosphere, sea surface and seawater and find that the short-wave infrared performs well in the above channels. The 450-nm pulse is used for generations of quantum signal carriers to accomplish quantum communications through atmosphere, sea surface and seawater channels. Numerical simulations show that the proposed scheme can achieve the transmission distance of 600 km. In addition, we demonstrate that non-Gaussian operations can further lengthen its maximal transmission distance, which contributes to the establishment of practical global quantum networks.