绝缘层LiF/Al电极对提高P-PPV发光器件发光性能的研究

为了提高聚合物电致发光器件中Ba（Ca）／Al阴极的稳定性,在该阴极与聚合物发光材料poly（2-（4-ethylexyl）phenyl-1,4-phenylene vinylene）（P-PPV）层之间插入一层7nm的LiF绝缘层,发光器件的发光性能在多项参数（发光器件的电压．电流特性、发光强度及外量子效率,以及电流效率等发光性能指标）上能够与工作性能优良但稳定性较差的Ba（Ca）／Al电极结构PLEDs器件的发光特性具有可比性。这对于研制高效率、高稳定的聚合物电致发光器件并最终将其用于商业目的,具有重大现实意义。     

HL-1装置离子温度的电荷交换法测定

本文叙述了用自己研制的六道中性粒子分析器(即中性粒子谱仪),测量HL-1托卡马克装置离子温度的实验,给出了在1986年进行的一组放电实验所得等离子体的离子温度及其随放电时间变化的结果,测得的中心离子温度的典型值为474eV,在相应等离子体参数下,Artsimovich经验公式给出450eV     

五次对称与Ti-Ni-V合金中的准晶

一、准晶的发现及研究现状近百年来,人们对凝聚态的深入研究表明,固态基本可分为晶态和非晶态两大类．当用一束Ｘ射线或电子束照射到固态上时,就会发现,只有晶体才会产生明锐的布喇格衍射,而非晶固体和液体只能产生很弥散的衍射．其原因就在于晶体中原子在三维空间中的排列具有平移周期性,从而保证了高度的相干性;而非晶固体和液体中原子排列则基本处于无序（或短程有序）状态,不具备这种空间相干性,从而只能得到如我?...     

A DOUBLE-TEMPERATURE-GRADIENT TECHNIQUE FOR THE GROWTH OF PURE C60 SINGLE CRYSTALS FROM THE VAPOR PHASE

Pure C₆₀ single crystals were grown by a sublimation-condensation method in an evacuated dosed quartz tube situated in a double-temperature-gradient furnace. Large C₆₀ single crystals, up to a size of 0.6 mm×1.0 mm×2.0 mm with quite smooth and shiny faces, were obtained. X-ray diffraction, electron diffraction and X-ray morphology were carried out and showed that the quality of large C₆₀ single crystals grown by the double-temperature-gradient technique is excellent. In this paper the experimental results of the growth of large C₆₀ single crystals are reported and the morphological and structural characterizations are discussed in detail.     

基于变分模态分解和自动编码器的PIN二极管温度特性预测

提出融合变分模态分解（VMD）和自编码器的预测方法,将温升特性曲线分解成若干个子信号分量,其中包含高频的波动量、中间量和低频的趋势量,然后利用自编码器对每个分量进行预测,最后将分量的预测值相加,从而实现对PIN二极管温升特性曲线的精准预测。通过与多种机器学习方法的对比验证了结合VMD分解可有效提升预测精度,同时也验证了自编码器在特性曲线拟合上的优势。     

基于神经网络和多目标优化算法的掺铋光纤放大器设计

掺铋光纤放大器有助于将光纤通信系统拓展至新的传输波段。然而,其增益和噪声性能存在相互制约的关系,提升增益往往会导致噪声性能的恶化,反之亦然。因此,提出一种结合反向传播神经网络(BPNN)和带精英保留策略的快速非支配排序遗传算法(NSGA-Ⅱ)的多目标优化方法,通过对两级掺铋光纤放大器结构进行设计,实现了增益和噪声性能的同时优化。使用经过训练的BPNN对增益和噪声系数预测的均方根误差分别为0.191和0.084,具有较高预测精度。以高增益和低噪声系数为目标,使用NSGA-Ⅱ算法进行优化,得到包含500个解的Pareto最优解集。优化后,放大器所能实现的平均增益范围为15～37 d B,相应的平均噪声系数范围为4.95～5.31 d B。利用BPNN代替求解耦合微分方程来评价个体适应度,使得优化时间较传统方法由10⁶ s左右降低为80 s左右,大幅提升了优化效率。所提方法也为其他掺杂光纤放大器的高效率、多目标结构优化设计提供了一种新的思路。     

高重复率脉冲分子束阀门

超声分子束是研究分子化学反应动力学及分子光谱的重要工具．它不仅具有无碰撞、高束流密度等特点,而且在超音速绝热膨胀过程中,转动和平动温度大幅度降低,减少了热带的影响,使得复杂的分子光谱简化,从而提高态选择性激发的效率,是研究分子高激发态光谱的理想设备．通常使用的超声分子束是连续分子束,由于它要求一定的束流密度,又要求真空室的真空度优于１０～（－３)Ｔｏｒｒ,这样就需要很大抽速的泵系统,因此分子束....     

分离电离室同步辐射束线位置监测器

本文介绍的分离电离室同步辐射光束线(在X射线能区)垂直位置监测器,可同时监测束线绝对垂直位置和相对总强度.束线无阻挡通过.常规X源实验结果表明原理可靠,方法简便,性能稳定,可投入实用.     

Predicting Quantum Many-Body Dynamics with Transferable Neural Networks

Advanced machine learning(ML)approaches such as transfer learning have seldom been applied to approximate quantum many-body systems.Here we demonstrate that a simple recurrent unit(SRU)based efficient and transferable sequence learning framework is capable of learning and accurately predicting the time evolution of the one-dimensional(ID)Ising model with simultaneous transverse and parallel magnetic fields,as quantitatively corroborated by relative entropy measurements between the predicted and exact state distributions.At a cost of constant computational complexity,a larger many-body state evolution is predicted in an autoregressive way from just one initial state,without any guidance or knowledge of any Hamiltonian.Our work paves the way for future applications of advanced ML methods in quantum many-body dynamics with knowledge only from a smaller system.     

Influence of external load on friction coefficient of Fe-polytetrafluoroethylene

A coarse-grained molecular dynamics simulation model was developed in this study to investigate the friction process occurring between Fe and polytetrafluoroethylene(PTFE).We investigated the effect of an external load on the friction coefficient of Fe–PTFE using the molecular dynamics simulations and experimental methods.The simulation results show that the friction coefficient decreases with the external load increasing,which is in a good agreement with the experimental results.The high external load could result in a larger contact area between the Fe and PTFE layers,severer springback as a consequence of the deformed PTFE molecules,and faster motion of the PTFE molecules,thereby affecting the friction force and normal force during friction and consequently varying the friction coefficient.