蛋白质对纳米铕岛膜表面荧光的增强作用

将经硫辛酸修饰的铕纳米颗粒和蛋白质固定在石英玻璃表面或胶原蛋白隔离的石英玻璃表面,研究蛋白质对纳米铕岛膜荧光的增强作用.研究结果发现,在275nm激发波长下,铕纳米岛膜的荧光光谱与铕纳米颗粒溶液的荧光性质相似,且微量蛋白质的加入可以使铕纳米岛膜的荧光强度增强,但被石英玻璃片吸附后,铕纳米岛膜以及铕-蛋白质体系的荧光发射峰的位置由378.8nm红移至420nm,且胶原蛋白隔离铕纳米岛膜和滴加微量BSA蛋白质的荧光光谱相似,但荧光强度没有发生明显变化.     

含色散介质的一维光子晶体微腔的透射谱

研究了含色散介质的一维光子晶体微腔的透射谱,对色散介质采用Lorentz振子模型,腔模的频率设置在光子晶体带隙中心。发现当吸收可以忽略时,色散效应将导致在腔模附近有很高的态密度,与此相应地在透射谱中出现一个较宽的透射带。当吸收存在时透射带中心的透射峰消失,但带尾的透射峰依然存在。     

基于高速肖特基二极管的100 ps瞬态取样门设计与仿真

 皮秒级瞬态取样门主要应用于激光聚变实验和高能物理实验中,对单次高速脉冲进行实时取样。提出了一种新颖的基于肖特基二极管桥的平衡取样门,给出其模型和具体电路设计。电路仿真结果表明,对称的选通设计保证了选通脉宽为100 ps时,取样间隔也为100 ps,取样门带宽为4.4 GHz,可应用于多路超短激光脉冲取样。     

介质加载环板慢波结构高频特性研究

 提出了一种适用于环板结构的计算等效相对介电常数的方法,利用变分法导出了介质加载环板慢波结构的色散方程和耦合阻抗表达式。计算结果表明,介质加载能够有效降低环板慢波结构的工作电压。计算结果与CST-MWS的模拟结果吻合良好,说明所提出的计算等效相对介电常数的方法和计算色散方程的方法对环板慢波结构是切实可行的。     

Gravitational field of a family of SU(5) dyons

By solving the coupled SU(5) Einstein-Yang-Mills-Higgs equations, we obtain the exact Reissner-Nordstrom type gravitational field of a family of spherically symmetric SU(5) dyons with magnetic charge 1/2e.     

Millimeter wave beams diffracted from reflecting gratings

According to the angular-spectrum method, a radiation beam of an antenna horn in the Fresnal region is decomposed into the plane waves with the fast Fourier transform algorithm and the waves diffracted from a reflection grating are superposed as a diffracted beam. Compared with the reflected beam from the same size mirror, the radiation half width of the diffracted beam from a grating is narrower and its lateral shape is shift. These performances have been experimentally verified at Ka-band by: (1). The relative diffraction efficiencies in the first order with two triangular gratings which is put along propagating direction of a beam produced by a conical lens-horn. (2). H-plane lateral width with power—3dB lapsed of the focus beam from a grating and a mirror in a grating spectrometer for millimeter waves (25–100 GHz).     

Quantum thermal field fluctuation induced corrections to the interaction between two ground-state atoms

We generalize the formalism proposed by Dalibard, Dupont-Roc, and Cohen-Tannoudji (the DDC formalism) in the fourth order for two atoms in interaction with scalar fields in vacuum to a thermal bath at finite temperature T, and then calculate the interatomic interaction energy of two ground-state atoms separately in terms of the contributions of thermal fluctuations and the radiation reaction of the atoms and analyze in detail the thermal corrections to the van der Waals and Casimir–Polder interactions. We discover a particular region, i.e. $\sqrt[4]{{\lambda }^{3}\beta }\ll L\ll \lambda $ with L, β and λ denoting the interatomic separation, the wavelength of thermal photons and the transition wavelength of the atoms respectively, where the thermal corrections remarkably render the van der Waals force, which is usually attractive, repulsive, leading to an interesting crossover phenomenon of the interatomic interaction from attractive to repulsive as the temperature increases. We also find that the thermal corrections cause significant changes to the Casimir–Polder force when the temperature is sufficiently high, resulting in an attractive force proportional to TL⁻³ in the λ ≪ β ≪ L region, and a force that can be either attractive or repulsive and even vanishing in the β ≪ λ ≪ L region depending on the interatomic separation.     

改进的时序多重稀疏贝叶斯学习冰下水声信道估计方法

针对时序多重稀疏贝叶斯学习信道估计方法计算复杂度高且在低信噪比时估计精度低的问题,本文提出了一种改进的时序多重稀疏贝叶斯学习正交频分复用冰下水声信道估计方法。首先,采用奇异值分解方法对接收导频矩阵进行去噪;随后利用去噪后的接收导频矩阵结合最小二乘信道估计方法获得时序多重稀疏贝叶斯信道估计的超参数矩阵、感知矩阵等先验知识;最后,利用冰下水声信道的稀疏特性和多途结构较为稳定的特点,采用时序多重稀疏贝叶斯信道估计对不同符号的冰下水声信道进行联合重建。仿真结果显示,在能量系数为0.03时,改进方法信道估计均方误差相比较于原始方法至少降低了约2.87×10^-5,运算时间至少下降了约为90%。第11次北极科学考察冰下试验结果显示,改进方法的平均原始误码率略微低于原始方法,平均运算时间降低约75%。研究结果表明,利用冰下水声信道的特点,改进方法可以实现高精度冰下水声信道估计,并且有效降低系统计算复杂度。     

Thermally Evaporated Ag–Au Bimetallic Catalysts for Efficient Electrochemical CO2 Reduction

CO₂ reduction reaction (CO₂RR) has indispensable significance for carbon recycling and renewable energy production. As typical electrochemical catalysts, Au and Ag show relatively high reaction activity and selectivity in CO₂RR. In this study, a series of Ag–Au bimetallic catalysts are designed and synthesized through the thermal evaporation method for efficient yet massive production of electrochemical catalysts. The Ag–Au catalysts show significantly enhanced activity and selectivity in CO₂RR, which is mainly attributed to the increased grain boundaries with well-dispersed single Ag atoms. After the optimization, Au20Ag10 exhibits the best performance with a CO Faraday efficiency of 89% at −0.9 V (vs the reversible hydrogen electrode) with good stability.     

减反膜对单晶硅太阳能电池性能的影响分析

在太阳能电池效率的评价中,电池材料、掺杂浓度、扩散长度等都是比较重要的参数,合理地改变相关参数可以优化太阳能电池的性能,提高电池效率。此外,在太阳能电池表面镀一层具有减反作用的光学薄膜（简称减反膜）也是提高电池效率的重要手段。以提高电池效率为目标,对单晶硅太阳能电池的掺杂浓度和扩散长度等微观参数进行计算优化,分析了掺杂浓度和扩散长度变化对电池效率的影响。并在此基础上分析了不同类型的减反膜对于电池效率的影响,给出了最佳减反膜材料及其膜系厚度,并且结合镀膜后电池量子效率的变化验证了其准确性。结果表明,在优化电池掺杂浓度和扩散长度的基础上,选择合适的减反膜,电池效率最高可达20.35%,相比于优化前提高了8.25%。