双离子(40Ar+, C2H+6)辐照合成金刚石纳米晶颗粒

用双离子(⁴⁰Ar⁺，C₂H⁺₆)辐照实验完成了从多壁碳纳米管向金刚石纳米晶颗粒的转变.对转变机理进行了初步探讨.这一探索有望能成为一种金刚石纳米晶合成的新途径.由此可知，多重荷能离子辐照用于其他材料纳米结构的制备也不是凭空设想. 关键词： 金刚石纳米晶 离子辐照 透射电子显微镜     

Kondo Resonance versus Fano Interference in Double Quantum Dots Coupled to a Two-Lead One-Ring System

We analyse the transport properties of a coupled double quantum dot （DQD） device with one of the dots （QD1） coupled to metallic leads and the other （QD2） embedded in an Aharonov-Bhom （A-B） ring by means of the slaveboson mean-field theory. It is found that in this system, the Kondo resonance and the Fano interference exist simultaneously, the enhancing Kondo effect and the increasing hopping of the QD2-Ring destroy the localized electron state in the QD2 for the QD1-leads, and accordingly, the Fano interference between the DQD-leads and the QD1-leads are suppressed. Under some conditions, the Fano interference can be quenched fully and the single Kondo resonance of the QD1-leads comes into being. Moreover, when the magnetic flux of the A-B ring is zero, the influence of the parity of the A-B ring on the transport properties is very weak, but this influence becomes more obvious with non-zero magnetic flux. Thus this model may be a candidate for future device applications.     

钕铁硼在高温超导磁悬浮技术实验中的应用

将新材料钕铁硼作为磁导轨引入到高温超导磁悬浮技术实验中,介绍了高温超导悬浮技术实验的基本原理、仪器及钕铁硼对实验的改进.     

纳米材料用于吸收电磁波的物理机制

本文从物理学的角度分析吸波材料与电磁波作用的影响因素和纳米材料在吸波应用上的微观机制，随着纳米材料和纳米科技的深入发展，纳米吸波材料将以更优异的性能广泛应用于军事装备和民用电磁波防护上．     

磁场和磁场力的相对性

静止的带电体只激发静电场，对电荷的作用只有静电场力；运动的带电体既激发电场，又激发磁场，对电荷的作用既有电场力又有磁场力．所以，磁场是电场的相对论效应．本文通过两个具体例子，说明了这一观点．     

Contrast Adaptation Decreases Complexity in Retinal Ganglion Cell Spike Train

The difference in temporal structures of retinal ganglion cell spike trains between spontaneous activity and firing activity after contrast adaptation is investigated. The Lempel-Ziv complexity analysis reveals that the complexity of the neural spike train decreases after contrast adaptation. This implies that the behaviour of the neuron becomes ordered, which may carry relevant information about the external stimulus. Thus, during the neuron activity after contrast adaptation, external information could be encoded in forms of some certain patterns in the temporal structure of spike train that is significantly different, compared to that of the spike train during spontaneous activity, although the firing rates in spontaneous activity and firing activity after contrast adaptation are sometime similar.     

Experimental Study on Electrostatic with Two Guiding of Supersonic D20 Molecular Beam Charged Wires

We demonstrate the guiding of a supersonic heavy-water （D2O） molecular beam using a hollow electrostatic field generated by the combination of two parallel charged-wires and two grounded metal-plates, and report some new and preliminary experimental results. In the experiment, we detect the guiding signals by using the method of time-of-flight mass spectrum and study the dependence of the relative transmission of the beam guide on the guiding voltage. Our study shows that the relative transmission of the beam guide is increased linearly with increasing guiding voltage Vguid, and the number of the guided D20 molecules is at least increased by 89.4% when the guiding voltage is ＋20.0k V. Finally, some potential applications of our guiding scheme in the molecule optics are briefly discussed.     

双离子(40Ar+,C2H6+)辐照合成金刚石纳米晶颗粒

用双离子(40Ar+,C1H6+)辐照实验完成了从多壁碳纳米管向金刚石纳米晶颗粒的转变.对转变机理进行了初步探讨.这一探索有望能成为一种金刚石纳米晶合成的新途径.由此可知,多重荷能离子辐照用于其他材料纳米结构的制备也不是凭空设想.     

2-硫代丁基-5-巯基-1，3，4-噻二唑Ag[I]修饰的钼硅酸盐纳米颗粒的制备及摩擦性能

以合成的2-硫代丁基-5-巯基-1，3，4-噻二唑为配体，在醇-水体系中制备了Keggin结构钼硅杂多阴离子有机衍生物的纳米颗粒，以透射电子显微镜、扫描电子显微镜、傅立叶变换红外光谱仪、热分析仪等测试手段对此纳米颗粒的形貌、组成和结构进行了表征，并在机械式四球长时抗磨损试验机上考察了其摩擦学性能．分散型实验结果表明化合物在有机溶剂中分散性能良好，红外光谱表明所合成的纳米颗粒具有杂多酸Keggin骨架结构无机核，透射电镜分析表明颗粒平均粒径约为10nm，热分析娃示分解温度范围为200～300℃．作为新型纳米润滑油添加剂，在最佳添加质量分数为0．05％，负荷300N，摩擦时间30min，转速1450r／min的条件下，与空白相比磨斑直径减小27．9％，摩擦系数减小15．3％．