中温固体氧化物燃料电池复合阴极材料LaBiMn2O6-Sm0.2Ce0.8O1.9的制备与电化学性质

采用甘氨酸燃烧法合成了LaBiMn_2O_6粉体,并与Sm_(0.2)Ce_(0.8)O_(1.9)均匀混合制备了LaBiMn_2O_6-Sm_(0.2)Ce_(0.8)O_(1.9)(LBM-SDC)复合阴极材料。利用X射线衍射(XRD)和扫描电子显微镜(SEM)对材料的物相及微观形貌进行分析,结果表明LBM与SDC在1 000℃下有良好的化学稳定性。SDC的复合增加了氧离子传导路径,进而使氧还原反应(ORR)速度加快。电化学阻抗谱(EIS)测试结果表明,复合阴极极化电阻(Rp)随SDC复合量的增加呈现先降低后升高的趋势,当复合量为30%(w/w)时,阴极材料的性能最优。在700℃空气气氛下的极化电阻为0.186Ω·cm~2,相对LBM(0.717Ω·cm~2)减少74%。氧分压测试结果表明阴极反应的速率控制步骤为氧分子的吸附-解离过程。以复合阴极构筑的电解质支撑单电池Ni-SDC/SDC/LBM-30%SDC在700℃的最大输出功率密度为234 mW·cm~(-2),连续测试90 h输出功率衰减约4%。     

B掺杂的石墨烯作为钠离子电池负极材料的研究

采用基于密度泛函理论的第一性原理方法,研究了本征石墨烯及缺陷石墨烯对钠原子的吸附行为.主要研究了三种石墨烯:本征石墨烯(P-graphene)、硼掺杂的石墨烯(Defect-Ⅰ)和硼掺杂的叽咯石墨烯(Defect-Ⅱ).结果表明,与P-graphene相比,Defect-Ⅰ和Defect-Ⅱ在吸附能、电荷密度、态密度和储钠量方面表现出很大的差异.Defect-Ⅰ和Defect-Ⅱ对钠原子的吸附能分别是-3.250 eV和-2.332 eV,约为P-graphene对钠原子吸附能的1.71倍和1.23倍.态密度计算结果表明,Defect-Ⅰ和Defect-Ⅱ中钠原子与硼原子发生轨道杂化,而P-graphene中不存在轨道杂化现象.Defect-Ⅰ和Defect-Ⅱ对钠原子的吸附量分别是9和8个,与P-graphene相比提高.因此,石墨烯中掺杂硼有望成为一种新型的储钠材料.     

Robust generation of high-fidelity entangled states for multiple atoms

A scheme is presented for generating entangled states of multiple atoms in a cavity. In the scheme the atoms simultaneously interact with a cavity mode, with the first atom driven by two classical fields and the other atoms driven by a classical field. Our scheme is valid even if the cavity decay rate is larger than the effective coupling strength, which is important for experiment. The generation of entangled states is conditional on the detection of a photon decaying from the cavity and thus the fidelity of the entangled state is insensitive to the detection inefficiency. Furthermore, the scheme can be applied to the case with any number of atoms in principle.     

煤焦油精制软沥青中氮、硫的分布和热稳定性的分析

以高温煤焦油为原料制备煤精制软沥青及其族组成,再炭化制备半焦。通过元素分析和红外光谱分析杂原子氮、硫的分布和热稳定性。     

Synthesis of Two-Color Laser Pulses for the Harmonic Cutoff Extension

Increasing simultaneously both the cutoff energy and efficiency is a big challenge to all applications of high-order harmonic generation(HHG).For this purpose,the shaping of the waveform of driving pulse is an alternative approach.Here,we show that the harmonic cutoff can be extended by about two times without reducing harmonic yield after considering macroscopic propagation effects,by adopting a practical way to synthesize two-color fields with fixed energy.Our results,combined with the experimental techniques,show the great potential of HHG as a tabletop light source.     

磁性Fe3O4@SiO2@CS镉离子印迹聚合物的制备及吸附性能

以SiO2包覆的纳米Fe3O4为载体, 壳聚糖(Chitosan, CS)为功能配体, γ-缩水甘油醚氧丙基三甲氧基硅烷为交联剂, 制备了磁性Fe3O4@SiO2@CS镉离子印迹聚合物(Magnetic ion-imprinted polymer, M-IIP). 采用扫描电镜和红外光谱对该磁性印迹聚合物进行了表征. 结果表明, 壳聚糖在环氧基硅烷交联作用下, 实现了印迹壳层在磁性Fe3O4表面的接枝, 该印迹材料是边长为60~120 nm的立方体. 吸附性能实验表明, M-IIP对Cd(Ⅱ)的吸附符合一级动力学吸附模型; M-IIP对Cd(Ⅱ)/Cu(Ⅱ), Cd(Ⅱ)/Zn(Ⅱ), Cd(Ⅱ)/Pb(Ⅱ)和Cd(Ⅱ)/Hg(Ⅱ)的相对选择系数分别为2.92, 3.43, 8.97和9.20. 原子吸收光谱检测结果表明, 该磁性Fe3O4@SiO2@CS离子印迹聚合物可用于水溶液中Cd(Ⅱ)的分离, Cd(Ⅱ)回收率在98%以上.     

聚（N,N-二烯丙基-N-丁氧羰甲基氯化铵）的合成及其杀菌性能

以N,N-二烯丙基-N-丁氧羰甲基氯化铵(DACBMAC)为单体,过硫酸铵为引发剂,采用水溶液聚合合成了聚(N,N-二烯丙基-N-丁氧羰甲基氯化铵)(PDACBMAC),用FT-IR和¹H NMR测试技术对其结构进行了表征,并研究了其对大肠杆菌的杀菌性能和抗菌机理。 结果表明,PDACBMAC对大肠杆菌的杀菌能力明显高于聚二甲基二烯丙基氯化铵(PDMDAAC),在剂量低于20 mg/L时,其杀菌能力稍高于十二烷基二甲基苄基氯化铵(DDBAC);其对大肠杆菌的杀菌率随特性粘数的增加而增加,当特性粘数为1.371 dL/g,剂量为30 mg/L时,杀菌率可达99.7%;其杀菌效果明显受pH值影响,在pH值为4.7~6.7时,杀菌率随pH值升高而增加,pH＞6.7时,其杀菌率随pH值升高而降低。 浊度测定结果表明,PDACBMAC具有优良的絮凝除浊能力。 β-半乳糖苷酶活性测定结果表明,PDACBMAC的抗菌机理是基于杀菌作用。     

A Super Extension of Kaup-Newell Hierarchy

With the help of the zero-curvature equation and the super trace identity, we derive a super extension of the Kaup--Newell hierarchy associated with a 3×3 matrix spectral problem and establish its super bi-Hamiltonian structures. Furthermore, infinite conservation laws of the super Kaup-Newell equation are obtained by using spectral parameter expansions.     

Preparation of Macroscopic Quantum-Interference States for a Collection of Trapped Ions Via a Single Geometric Operation

We describe a scheme for the generation of macroscopic quantum-interference states for a collection of trapped ions by a single geometric phase operation. In the scheme the vibrational mode is displaced along a circle with the radius proportional to the number of ions in a certain ground electronic state. For a given interaction time, the vibrational mode returns to the original state, and the ionic system acquires a geometric phase proportional to the area of the circle, evolving from a coherent state to a superposition of two coherent states. The ions undergo no electronic transitions during the operation. Taking advantage of the inherent fault-tolerant feature of the geometric operation, our scheme is robust against decoherence.     

TaN/TiN和NbN/TiN纳米结构多层膜超硬效应及超硬机理研究

采用射频磁控溅射方法制备单层TaN,NbN和TiN薄膜和不同调制周期的TaN/TiN和NbN/TiN纳米多层膜.薄膜采用X射线衍射仪、高分辨率透射电子显微镜和显微硬度仪进行表征.结果表明TaN/TiN和NbN/TiN纳米多层膜在一定的调制周期范围内均呈共格界面,相应地均出现了超硬效应,且最大硬度值接近.分析了TaN/TiN与NbN/TiN纳米多层膜的超硬机理,TaN/TiN的晶格错配度与NbN/TiN的接近,但TaN/TiN的弹性模量差与NbN/TiN的有一定的差别,表明由于晶格错配使共格外延生长在界面处 关键词： TaN/TiN纳米多层膜 NbN/TiN纳米多层膜 外延生长 超硬效应