摘要：A silicon-based photonic switch is proposed and simulated based on the multimode interference （MMI） principle and the free-carrier plasma dispersion effect in silicon-germanium. The proposed switch, designed for 1.55μm window operation,is useful for DWDM optical networks. The switch consists of two input single-mode ridge waveguide ports,a MMI section, and three output single-mode ridge waveguide ports. In the MMI section, two index-modulation regions are placed to divert input optical signals from the two input ports to each of the three output ports. Switching characteristics are demonstrated theoretically by a beam propagation method for 1.55μm operation. The simulated results show that the insertion loss of the switch is less than 1.43dB, and the crosstalk is between - 18 and - 32.8dB.

摘要：光子晶体,特别是三维光子晶体,可能成为信息处理和通信等领域的新型功能材料.光子晶体的制作方法可分为"自上而下"的物理方法和"自下而上"的化学自组装方法.化学自组装方法是制作三维光子晶体最为经济有效的方法.本文在阐述自组装方法的种类、一般过程、优点和不足等内容的基础上,分别分析和总结了带有各种功能缺陷的三维光子晶体的制作,这些缺陷主要包括线缺陷、面缺陷和点缺陷.从研究中可以看出,化学自组装方法通常需要结合其他方法才能实现缺陷的嵌入.近些年,三维光子晶体制作在材料选取、结构设计和方法改进等方面都有一些最新进展,本文对此进行了较为详尽的评述,并对我们课题组的研究进行了总结.最后对光子晶体的研究和制作方向进行了展望.

摘要：柔性有机突触晶体管(FOSTs)由于其灵活性、生物相容性、易于加工和低复杂性而引起了广泛关注.然而,FOSTs很难在满足装置变形要求的同时保持其突触性质的机械稳定性.在此,我们通过实验发现,弯曲变形对FOSTs的突触性能(即兴奋性突触后电流(EPSC)值)的影响大于对导通电流的影响.此外,通过公式推导,我们证明了通道附近产生的弯曲诱导缺陷状态的密度显著影响突触性能.我们提出了一种使用封装层调整器件稳定段的通用方法.无调节稳定段的普通FOSTs的EPSC值在弯曲后下降了近1.5-2个数量级.相比之下,设计的柔性突触装置表现出相对稳定的EPSC.此外,设计的FOSTs表现出稳定的成对脉冲促进、长期增强和光学突触性能.此外,使用手写人工神经网络在500次弯曲循环前后基于我们的设备进行神经形态计算模拟,该设备在50个学习周期后显示出稳定的识别精度(初始状态下91.55%,500个弯曲周期后90.43%).稳定段在柔性突触晶体管中的成功应用为制造具有机械稳定性的柔性神经形态电子器件提供了一个方便和简单的思路.

摘要：Hydrogel-Ⅰ was fabricated via sodium alginate in situ-embedding with MAL powders and then applied to decontaminating Pb(Ⅱ) from water. Conditions for preparing Hydrogel-Ⅰ and the adsorption of Pb(Ⅱ) over Hydrogel-I were optimized through response surface methodology coupled with central composite design. XPS revealed that the groups of —OH, —COO—, —NH, —NHand —CSS— carried by Hydrogel-Ⅰ were responsible for the uptake of Pb(Ⅱ). Ions exchange, surface complexation, electrostatic attraction and pore-filling effect contributed to the adsorption process. Adsorption performances of Pb(Ⅱ) by Hydrogel-Ⅰ and MAL powders were compared. Although they exhibited similar adsorption rate and maximum adsorption capacity(qm), the reusing ability of Hydrogel-Ⅰ was better and it was easier to be separated from aqueous solution after treatment. Even compared with organic hydrogel materials,Hydrogel-Ⅰ presented relatively quick adsorption speed and high adsorption capacity. It can be concluded that Hydrogel-Ⅰ could be an alternative scavenger for the treatment of Pb(Ⅱ) from aqueous solution.

摘要：Single-atom catalysts(SACs)have been widely used in heterogeneous catalysis owing to the maximum utilization of metal-active sites with controlled structures and well-defined *** tailored coordination with nitrogen atom,the metal-nitrogen(M-N)-based SACs have demonstrated interesting physical,optical and electronic properties and have become intense in photocatalysis and electrocatalysis in the past *** substantial efforts in constructing various M–N-based SACs,the principles for modulating the intrinsic photocatalytic and electrocatalytic performance of their active sites and catalytic mechanism have not been sufficiently ***,the present review intends to shed some light on recent research made in studying the correlation between intrinsic electronic structure,catalytic mechanism,single-metal atom(SMA)confinement and their photocatalytic and electrocatalytic activities(conversion,selectivity,stability and etc).Based on the analysis of fundamentals of M–N-based SACs,theoretical calculations and experimental investigations,including synthetic methods and characterization techniques,are both included to provide an integral understanding of the underlying mechanisms behind improved coordination structure and observed ***,the challenges and perspectives for constructing highly active M–N based photocatalysis and electrocatalysis SACs are *** particular,extensive technical and mechanism aspects are thoroughly discussed,summarized and analyzed for promoting further advancement of M-N-based SACs in photocatalysis and electrocatalysis.

摘要：Flexible thin-film organic semiconductor devices have received wide attention due to favorable properties such as light-weight,flexibility,reproducible semiconductor resources,easy tuning of functional properties via molecular tailoring,and low cost large-area *** them,ultraflexible electronics,usually with minimum bending radius of less than 1 mm,are essential for the development of epidermal and bio-implanted electronics,wearable electronics,collapsible and portable electronics,three dimensional(3D) surface compilable electronics,and *** review firstly gives a brief introduction of development from flexible to ultraflexible organic semiconductor electronics,and design of ultraflexible devices,then summarizes the recent advances in ultraflexible thin-film organic semiconductor devices,focusing on organic field effect transistors,organic light-emitting diodes,organic solar cells and organic memory devices.

摘要：Electrochemical CO2 reduction to chemicals or fuels presents one of the most promising strategies for managing the global carbon balance, which yet poses a significant challenge due to lack of efficient and durable electrocatalyst as well as the understanding of the CO2 reduction reaction(CO2RR) *** from the large surface area, high electrical conductivity, and tunable structure, carbon-based metal-free materials(CMs) have been extensively studied as cost-effective electrocatalysts for *** development of CMs with low cost, high activity and durability for CO2RR has been considered as one of the most active and competitive directions in electrochemistry and material *** this review article,some up-to-date strategies in improving the CO2RR performance on CMs are ***, the approaches to optimize the adsorption of CO2RR intermediates, such as tuning the physical and electronic structure are introduced, which can enhance the electrocatalytic activity of CMs ***, some design strategies are proposed to prepare CMs with high activity and selectivity for CO2RR.

摘要：The Pt-based catalyst tends to be poisoned by carbon monoxide(CO)-like intermediates produced in fuel cell reactions,which seriously deteriorates its catalytic ***,noble metal Au with the capacity of resistance to CO-like intermediates poisoning was employed to construct multi-element Pt-based *** trimetallic NiPtAu hollow nanocrystals(HNCs)with different surface Au contents were synthesized to explore the role of Au in electrocatalysis for alkaline methanol oxidation reaction(MOR).The trimetallic NiPtAu-SRAu HNCs catalyst with the relative rich Au content(15.17 at%)on surface exhibits a much lower CO oxidation peak potential than the other HNCs counterpart and 20 wt%Pt/C,which indicates the more exceptional CO-resisting ***,the MOR specific activity of NiPtAu-SRAu HNCs(31.52 mA cm^−2)is 7 times higher than that of 20wt%Pt/C(4.50 mA cm^−2).This enhancement in catalytic activity as well as anti-CO poisoning capability for NiPtAu-SRAu HNCs can be mainly ascribed to the weakened CO adsorption due to the exposure of Au atoms on NiPt surface evidenced by the experimental data and density functional theory *** study not only investigates the role of Au in MOR catalysis but also could be helpful for designing and optimizing the electrocatalysts for high-active and robust fuel cell applications.

摘要：核衣壳蛋白 (N)是传染性支气管炎病毒的主要结构蛋白之一。以前的研究结果显示 IBV- ZJ971毒株以引起腺胃肿大为特征 ,IBV- X和 N毒株以引起肾炎为特征。为了探讨不同组织嗜性传染性支气管炎病毒 N基因的变异 ,我们依据已发表的 IBV- Beaudette毒株 N基因的序列设计和合成引物 ,RT-PCR扩增 IBV- ZJ971、N、X和 H5 2的核衣壳蛋白基因 ,并测序、分析和在 ***中进行表达。结果显示 :IBV- ZJ971、N、X和 H5 2毒株的 N基因的 ORF由 12 30 bp组成 ,编码 4 0 9个氨基酸。与来源于 Gen Bank中的 IBV毒株比较 ,IBV- ZJ971、N、X和 H5 2与其它 IBV毒株的核苷酸同源性分别是 87.0 - 98.6 %、86 .6 - 99.7%、86 .3- 99.7%、87.2 % - 98.5 % ,氨基酸的同源性分别是 90 .0 - 97.8%、 90 .5 - 98.8%、 90 .0 -98.8%、 91- 98%。IBV- ZJ971毒株的 N蛋白不同于其他 IBV的独特变异是 111,117,14 2 ,171和 4 0 1位点上的氨基酸改变 ,IBV- N和 X毒株的 N蛋白不同与其它 IBV的独特变异是 4 6 ,4 8,189,190 ,2 2 0 ,2 2 3,2 36 ,2 37,2 4 0 ,2 86 ,2 99,30 1334,335 ,336 and35 1位点上的氨基酸改变。说明 IBV嗜腺胃毒株(ZJ971)和嗜肾毒株 (N和 X)的 N基因以散在的点突变为特征。将 IBV- ZJ971毒株的 N基因在 E.

摘要：Increasing the density and thickness of electrodes is required to maximize the volumetric energy density of lithium-ion batteries for practical ***,dense and thick electrodes,especially highmass-content(>50 wt%) silicon anodes,have poor mechanical stability due to the presence of a large number of unstable interfaces between the silicon and conducting components during *** we report a network of mechanically robust carbon cages produced by the capillary shrinkage of graphene hydrogels that can contain the silicon nanoparticles in the cages and stabilize the silicon/carbon *** situ transmission electron microscope characterizations including compression and tearing of the structure and lithiation-induced silicon expansion experiments,have provided insight into the excellent confinement and buffering ability of this interface-strengthened graphene-caged silicon nanoparticle anode ***,a dense and thick silicon anode with reduced thickness fluctuations has been shown to deliver both high volumetric(>1000 mAh cm^-3) and areal(>6 mAh cm^-2)capacities together with excellent cycling capability.