Adaptive Ionogel Paint from Room-Temperature Autonomous Polymerization of α-Thioctic Acid for Stretchable and Healable Electronics

Development of a universal stretchable ionic conductor coating on insulating substrates, irrespective of surface chemistry and substrate shapes, is of immense interest for compliant and integrative large-area electronics but has proved to be extremely challenging. Existing methods relying either on the concurrent deposition of polymerizing precursors or on divided formulation and painting processes both suffer from several limitations in terms of adhesion, dehydration, processability, and surface pre-treatment. Here an ionogel paint that is readily prepared from the concentration-induced autonomous ring-opening polymerization of a natural small molecule—α-thioctic acid (TA) at ambient conditions is reported. The presence of ionic liquid prevents polyTA from further depolymerization via forming COOH···OS hydrogen bonds, resulting in ultra-stretchable ionogels with widely tunable mechanical and conductive properties, self-healability, as well as tissue-like strain adaptability. Moreover, owing to its universal adhesion and adjustable rheology, the ionogel paint can be directly coated on diverse substrates with arbitrary shapes (including porous materials, 3D printed frames, and elastic threads) to render them ionic conductivity. Applications of the ionogel-coated substrates as skin-like highly sensitive and durable large-strain sensors are further demonstrated, suggesting the ionogel paint's great potential in the emerging soft and stretchable electronics.     

Modeling Diffusion in Functional Materials: From Density Functional Theory to Artificial Intelligence

Diffusion describes the stochastic motion of particles and is often a key factor in determining the functionality of materials. Modeling diffusion of atoms can be very challenging for heterogeneous systems with high energy barriers. In this report, popular computational methodologies are covered to study diffusion mechanisms that are widely used in the community and both their strengths and weaknesses are presented. In static approaches, such as electronic structure theory, diffusion mechanisms are usually analyzed within the nudged elastic band (NEB) framework on the ground electronic surface usually obtained from a density functional theory (DFT) calculation. Another common approach to study diffusion mechanisms is based on molecular dynamics (MD) where the equations of motion are solved for every time step for all the atoms in the system. Unfortunately, both the static and dynamic approaches have inherent limitations that restrict the classes of diffusive systems that can be efficiently treated. Such limitations could be remedied by exploiting recent advances in artificial intelligence and machine learning techniques. Here, the most promising approaches in this emerging field for modeling diffusion are reported. It is believed that these knowledge‐intensive methods have a bright future ahead for the study of diffusion mechanisms in advanced functional materials.     

氢诱导二维硫族化合物PtX2的电磁特性研究

为了充分研究二维重过渡金属硫族化合物材料在磁性器件中的潜在应用,基于自旋极化密度泛函理论,文中研究了氢化单层PtX₂(X=S,Se,Te)的稳定性和电磁特性。研究结果表明,单层PtX₂在氢化后具有较高的稳定性,且稳定性随硫族原子序数的增加而下降;氢化使单层PtX₂出现了磁矩,使其从半导体变为铁磁性的金属,该磁矩主要来自于窄反键子能带自旋极化下的Pt 5d电子。此外,单层PtX₂的铁磁性也随着硫族原子序数的增加而出现了下降的趋势。因此,文中的研究成果为设计二维重过渡金属硫族化合物材料的铁磁性提供了参考。     

外电场影响HMX/MDNI复合物感度的理论研究

为研究外电场对炸药感度的影响,采用量子力学方法在M06-2X∥B3LYP/6-311++G(d,p)水平上对奥克托今(HMX)/1-甲基-4,5-二硝基咪唑(MDNI)分别施加不同大小的外电场(-0.010~0.010 a.u.),得到不同外电场下的稳定构型。分析了各稳定构型的分子间相互作用、引发键解离能、硝基基团电荷、电子密度拓扑、电子密度转移及表面静电势的变化。结果表明:随着正向外电场的增强,HMX的引发键键长变短,解离能增加,感度降低,负向外电场时则相反;采用B3LYP方法所得3种复合物的解离能与外电场的相关系数分别达到了0.995、0.977和0.982;负向外电场作用下硝基基团所带负电荷减少,使炸药感度增加;电子密度拓扑分析表明,外电场作用下,HMX与MDNI分子间仍存在微弱的氢键作用;电子密度转移分析表明正向外电场增强了引发键的强度;分子表面静电势则进一步表明在正向外电场作用下炸药感度降低,负向时感度增加。     

Universal Interface between Functional Oxides and Silicon

Integration of crystalline oxides with silicon provides a versatile platform to extend and advance silicon technology. The interface between oxide and Si controls the structure and functional properties of the resulting material. In particular, the formation of a submonolayer metal phase on silicon is the standard approach to stabilize the epitaxial growth of oxides. However, fundamental questions—a) whether the interface transforms in the process of the synthesis; and b) if it is possible to control the interface and its electronic structure by varying the submonolayer template—remain unanswered. The present study employs MBE synthesis of EuO and SrO on Si(001) to demonstrate that the structure of the oxide/Si interface does not depend on the type of the template, its symmetry, and stoichiometry. Chemical transformations of the templates converging into the same 2D product are detected in situ by electron diffraction. Then, the common interfacial structure of 1D periodicity is visualized by high-resolution electron microscopy. The study provides insights into the process of oxide integration with silicon but also sets the limits in designing oxide/Si interfaces.     

分段预测函数控制及应用

导弹在飞行过程中受到多种因素的影响,其传递函数在不断变化,常规控制方法很难满足控制要求.复杂的控制方法往往因计算量大,耗时较多而不能满足响应的快速性.预测函数控制法计算量小,且能适应系统参数一定程度的变化,但系统参数变化较大时,控制效果将下降.对导弹运行过程进行了研究,将飞行时间分段,每段以对应的特征参数作为预测模型的参数,采用预测函数控制的方法进行控制.研究结果表明,这种控制方法控制效果较好,且能满足快速性的要求,具有一定的实用价值.     

飞行器智能控制系统研究进展

进行了飞行器智能控制系统研究进展的分析与综述。简要回顾了基于动态专家系统的飞行器自适应控制系统和当今广泛采用的飞行器"参谋"控制系统;在对智能系统发展趋势进行分析的基础上,推荐了建立在阿诺辛提出的功能系统理论基础上的最具发展前景的智能系统,给出了结构框图,详细介绍了作为该型智能系统中核心模块的预测算法、控制算法、目标综合和动态专家系统的构建问题;介绍了功能-智能系统用于飞行器控制的最新成果,描述了系统框图和关键部分的实现过程,并给出了对系统性能的仿真研究结果。在对智能控制系统的功能结构及其算法进行分析的基础上,给出了在实际应用中建立有效和性能良好的智能系统的建议。     

功能性双歧因子钙奶复合冰淇淋的开发研制

本文简述了功能性食品──双歧因子钙奶复合冰淇淋的营养成份及其对人体的作用,并对该工艺和配方进行研究,研制出风味佳,具有一定营养保健功能新型冰淇淋制品,并提出了宜于工业化生产的工艺参数和数据。     

Composite Nanostructures of TiO2 and ZnO for Water Splitting Application: Atomic Layer Deposition Growth and Density Functional Theory Investigation

The commercialization of solar fuel devices requires the development of novel engineered photoelectrodes for water splitting applications which are based on redundant, cheap, and environmentally friendly materials. In the current study, a combination of titanium dioxide (TiO₂) and zinc oxide (ZnO) onto nanotextured silicon is utilized for a composite electrode with the aim to overcome the individual shortcomings of the respective materials. The properties of conformal coverage of TiO₂ and ZnO layers are designed on the atomic scale by the atomic layer deposition technique. The resulting photoanode shows not only promising stability but also nine times higher photocurrents than an equivalent photoanode with a pure TiO₂ encapsulation onto the nanostructured silicon. Density functional theory calculations indicate that segregation of TiO₂ at the ZnO surfaces is favorable and leads to the stabilization of the ZnO layers in water environments. In conclusion, the novel designed composite material constitutes a promising base for a stable and effective photoanode for the water oxidation reaction.     

稀疏编码在静息态核磁共振图像中的应用

为了提取静息态的默认网络,降低核磁共振图像中的数据运算量,本文提出了数据降维和非线性变换的方法。首先,对核磁共振图像进行主成分分析,降低运算维度和数据复杂度。然后,对静息核磁数据进行稀疏编码学习,提取默认网络。实验结果表明,稀疏编码学习的效果优于传统的独立成分分析,且前者提取默认网络更加迅速,噪声更低。