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.     

Autaptic modulation-induced neuronal electrical activities and wave propagation on network under electromagnetic induction

Based on an improved HR neuron model, the effects of electrical and chemical autapses on the firing activities of single neurons are studied, and the wave propagation in forward feedback neural network is also discussed by considering autapstic regulation under different intensities of electromagnetic induction. It is found that the electrical activities of single neuron can be changed by exerting excitatory or inhibitory of electrical and chemical autapses. With different feedback gains of electromagnetic induction current, membrane potential shows the oscillatory solutions and steady states. Under the condition of different autapse or electromagnetic induction, the propagation of electrical activities caused by the central neuron is transformed in the forward feedback network. Moreover, the spatial synchronization of the network will be changed by choosing different coupling intensities and feedback gains. It is proved that the electrical and chemical autapses play a significant role in firing modes of single neuron and the wave propagation of the forward feedback networks under the electromagnetic induction.     

Atomistic simulation of the coupled adsorption and unfolding of protein GB1 on the polystyrenes nanoparticle surface

Understanding the processes of protein adsorption/desorption on nanoparticles’ surfaces is important for the development of new nanotechnology involving biomaterials; however, an atomistic resolution picture for these processes and for the simultaneous protein conformational change is missing. Here, we report the adsorption of protein GB1 on a polystyrene nanoparticle surface using atomistic molecular dynamic simulations. Enabled by metadynamics, we explored the relevant phase space and identified three protein states, each involving both the adsorbed and desorbed modes. We also studied the change of the secondary and tertiary structures of GB1 during adsorption and the dominant interactions between the protein and surface in different adsorption stages. The results we obtained from simulation were found to be more adequate and complete than the previous one. We believe the model presented in this paper, in comparison with the previous ones, is a better theoretical model to understand and explain the experimental results.     

Controlled Remote State Preparation of an Arbitrary Two-Qubit State by Using Two Sets of Four-Qubit GHZ States

Recently, Huang and Zhao (Int. J. Theor. Phys. 56, 678, 2017) proposed a new scheme for controlled remote state preparation of an arbitrary two-qubit state by using two sets of three-qubit GHZ states as the quantum channel. In the scheme, Alice and Bob choose four different kinds of two-qubit projective measurement bases to measure their local qubits, respectively. We demonstrate that two sets of four-qubit GHZ states can be used to realize the deterministic controlled remote state preparation of an arbitrary two-qubit state by performing only two-qubit projective measurements.     

Modification on C217 by auxiliary acceptor toward efficient sensitiser for dye-sensitised solar cells: a theoretical study

In this work, to develop efficient organic dye sensitisers, a series of novel donor–acceptor–π–acceptor metal-free dyes were designed based on the C217 dye by means of modifying different auxiliary acceptors, and their photovoltaic performances were theoretically investigated with systematic density functional theory calculations coupled with the incoherent charge-hopping model. Results showed that the designed dyes possess lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels as well as narrower HOMO–LUMO gaps compared to C217, which indicate their higher light-harvesting efficiency. In addition, using the (TiO₂)₃₈ cluster and bidentate bridging model, we predicted that the photoelectric conversion efficiency (PCE) for the C217 dye is as high as 9.92% under air mass (AM) 1.5 illumination (100 mW·cm^?2), which is in good agreement with its experimental value (9.60%–9.90%). More interestingly, the cell sensitised by the dye 7 designed in this work exhibits a middle-sized open-circuit voltage of 0.737 V, large short-circuit photocurrent density of 21.16 mA?cm^?2 and a fill factor of 0.801, corresponding to a quite high PCE of 12.49%, denoting the dye 7 is a more promising sensitiser candidate than the C217, and is worth further experimental study.     

腔场耦合的二能级原子荧光谱

过光与物质相互作用的主方程计算了强场激励的二能级原子与单模腔耦合的稳态荧光谱。在腔场的强耦合作用下,三峰Mollow谱的每个成分都分裂为多重的,这种现象由腔场使原子修饰态能级漂移而导致的,荧光谱的具体结构则依赖于驱动场的拉比频率和原子-腔的耦合系数。     

少周期激光脉冲附加太赫兹场对高次谐波发射的影响

本文通过数值求解非伯恩奥本海默近似下电子一维核一维的含时薛定谔方程,研究了少周期线偏振激光与氢分子离子相互作用下,太赫兹场的加入对高次谐波的发射影响.我们发现,在短周期线偏振激光脉冲的y方向上附加一个强度较弱的太赫兹场可以有效地扩展谐波的截止位置,并对量子轨道实现调控.通过时频分析、电子波包随时间变化以及半经典三步模型研究了高次谐波发射的物理机制,并对获得的物理现象给出合理的解释.     

Korteweg-de Vries方程的准孤立子解及其在离子声波中的应用

应用推广的tanh函数展开法,给出了Korteweg-de Vries方程具有准孤立子行为的两组孤子-椭圆周期波解,其中一组为新解.推导了均匀磁化等离子体中描述离子声波动力学行为的Korteweg-de Vries方程,发现电子分布、离子电子温度比、磁场大小、磁场方向对离子声准孤立子的波形具有显著影响.     

空心Fe_3O_4纳米微球的制备及超顺磁性

采用水热控制合成法,以六水三氯化铁、柠檬酸三钠和尿素为原料,聚丙烯酰胺为稳定剂, 200?C下反应12 h制备得到了超顺磁性空心Fe_3O_4纳米微球.通过X射线衍射仪、扫描电子显微镜、透射电子显微镜对样品的结构和形貌进行表征,并采用振动样品磁强计测试了样品的磁性能.结果表明:所得样品为具有尖晶石结构的Fe_3O_4纳米微球,尺寸为160 nm左右,呈分等级结构,即整个微球由粒径约18 nm的初级晶粒自组装堆叠而成;室温下表现为典型的超顺磁性,且饱和磁化强度为73.3 emu/g (1 emu/g=1 A·m~2/kg),这种高饱和磁化强度可以由其初级晶粒晶化程度高且粒径较大以及这种特殊的二次自组装结构进行解释.这种Fe_3O_4纳米微球为疏松多孔的空心球状结构,具有粒径分布均匀、分散性良好和超顺磁性的特点,在药物靶向输运和肿瘤热疗中有潜在的应用.