石墨烯碳纳米管复合结构渗透特性的分子动力学研究

采用经典分子动力学方法研究了压力驱动作用下水在石墨烯碳纳米管复合结构中的渗透特性.研究结果表明,水分子渗透通过石墨烯碳纳米管复合结构的渗透率明显高于石墨烯碳纳米管组合结构.水在石墨烯碳纳米管复合结构中的渗透率随着压强的升高而增大,随着电场强度的增大而减小.考虑了温度和复合结构中双碳管轴心距对水渗透性的影响规律.系统温度越高,水的渗透率越高;随着双碳管轴心距的增加,水的渗透率逐渐降低.通过计算分析水流沿渗透方向的能障分布,解释了各参数变化对水在石墨烯碳管复合结构中渗透特性的影响机理.研究结果将为基于石墨烯碳管复合结构的新型纳米水泵设计提供一定的理论依据.     

Magnetic and electrical transport properties of delta-doped amorphous Ge:Mn magnetic semiconductors

We report on the growth and characterization of delta-doped amorphous Ge:Mn diluted magnetic semiconductor thin films on GaAs (0 0 1) substrates. The fabricated samples exhibit different magnetic behaviors, depending on the Mn doping concentration. The Curie temperature was found to be dependent on both the Mn doping concentration and spacing between the doping layers. A sharp drop in magnetization and rise in resistivity are observed at low temperature in samples with high Mn doping concentrations, which is also accompanied by a negative thermal remanent magnetization (TRM) in the higher temperature range. The temperature at which the magnetization starts to drop and the negative TRM appears show a correlation with the Mn doping concentration. The experimental results are discussed based on the formation of ferromagnetic regions at high temperature and antiferromagnetic coupling between these regions at low temperature.     

基于NW型小世界人工神经网络的污水出水水质预测

为了预测污水处理出水水质,针对污水处理过程具有多变量、非线性、时变性、严重滞后的特点,提出了基于NW型小世界人工神经网络的污水处理出水水质预测模型。首先根据污水处理系统确定模型输入输出变量个数,然后建立了多层前向小世界神经网络模型,并对网络模型的隐层结构进行了优化研究。借助污水处理过程的历史数据进行了仿真研究,结果表明：和同规模的多层前向人工神经网络相比,小世界神经网络对污水出水水质预测具有较高精度和收敛速度,为污水出水水质的实时预测提供了一种有效的新方法。     

Observation of Non-Hermitian Quantum Correlation Criterion in Mesoscopic Optomechanical System

Although many quantum correlation criteria have been proposed successively in recent years, it is still an open question how to observe these criteria with the non–Hermitian terms in themselves. We propose an indirect scheme in this paper to observe non-Hermitian criteria and to judge whether or not quantum correlation exists in the system even though the expectation value measurement of non-Hermitian operator is invalid in quantum mechanics system. Our idea is to establish a critical state of mesoscopic oscillator under mean–field approximation, and the oscillator state will take place transition when the quantum correlation destroys the mean–field approximation. The non–Hermitian measurement will replace the position measurement in this process and it can be seen as a non–destructive detection. We give an example to explain this idea in a designed mesoscopic optomechanical system.     

高场应力及栅应力下AlGaN/GaN HEMT器件退化研究

采用不同的高场应力和栅应力对AlGaN/GaN HEMT器件进行直流应力测试,实验发现：应力后器件主要参数如饱和漏电流,跨导峰值和阈值电压等均发生了明显退化,而且这些退化还是可以完全恢复的;高场应力下,器件特性的退化随高场应力偏置电压的增加和应力时间的累积而增大;对于不同的栅应力,相对来说,脉冲栅应力和开态栅应力下器件特性的退化比关态栅应力下的退化大.对不同应力前后器件饱和漏电流,跨导峰值和阈值电压的分析表明,AlGaN势垒层陷阱俘获沟道热电子以及栅极电子在栅漏间电场的作用下填充虚栅中的表面态是这些不同应 关键词： AlGaN/GaN HEMT器件 表面态(虚栅) 势垒层陷阱 应力     

圆形面偶极层的静电势

讨论了圆形面偶极层静电势问题的正确解法,阐明了对于延拓法的正确理解,给出了有限间距时圆形平行板（分别带有异性面电荷）的静电势问题。     

Parallel laser microfabrication of terahertz metamaterials and its polarization-dependent transmission property

Large-area split ring resonator (SRR) array was fabricated by femtosecond laser micro-lens array lithography at a fast speed. Transmission spectra of the SRR arrays at different incident terahertz wave polarization states were characterized by terahertz time domain spectroscopy. A polarization-dependent transmission property of the SRR array was observed. Polarization-dependent loss (PDL) spectrum was characterized to investigate the polarization properties of the terahertz metamaterials. The PDL characterization can eliminate the substrate effect and provide a flexible platform to study the characteristics of free-standing terahertz metamaterials.     

具有生物活性钼钨仿生配合物与ATP作用的NMR研究

在常温下合成了以邻苯二酚为配体,分别以乙二胺、1,2-丙二胺、1,3-丙二胺为抗衡离子的7种手性钼钨八面体配合物(NH2CH2CH2NH3)3[Mo(V)O2(OC6H4O)2](1),(NH2CH2CH2NH3)2[W(VI)O2(OC6H4O)2](2),(NH2CH2CH2NH3)2.5[Mo(V)0.5W(VI)0.5O2(O2C6H4)]2](3),(NH3CH2CHNH2CH3)3[Mo(V)O2(OC6H4O)2](4),(NH3CH2CHNH2CH3)2[W(VI)O2(OC6H4O)2](5),(NH3CH2CHNH2CH3)2.5[Mo(V)0.5W(VI)0.5O2(OC6H4O)2](6),(NH3CH2CH2CH3NH2)2.5[Mo(V)0.5W(VI)0.5O2(OC6H4O)2](7),并在生理条件下对其与ATP的相互作用进行了液体NMR研究,发现标题配合物的中心金属离子在纯D2O溶剂中大多数以+5价形式存在,W(VI)被还原为W(V),但与ATP混合后又转化为+6价,配合物原有的顺磁性特征完全消失.研究还发现ATP可以促进中心离子与原配体发生解离.     

基于VxWorks新型映像的三模冗余启动机制研究

针对VxWorks启动映像依赖于ROM地址,不能适应航天型号中三模存储要求的缺点,利用VxWorks自带的压缩算法,按照航天型号软件任务要求设计了一种基于VxWorks内存型映像的新型压缩映像,实现了软件映像与ROM区地址无关。并且实现了新型压缩映像的三模冗余引导启动,启动时每一个bit数据都从三份映像获取,并进行三取二判断,将最后结果拷贝到内存作为目的映像的bit数据,目的映像启动后能够回写正确数据自动纠正空间环境下可能发生的单粒子翻转错误,为软件的可靠启动建立了基础。     

Research on taper zone coupling from single-core fiber to annular-core hollow beam fiber

Optical Review - We designed and manufactured a novel annular-core hollow beam fiber which could directly yield ring light with a central dark spot inside the beam employing MCVD technique and a...