路灯自动控制器

本文介绍了一种具有抗短时强光干扰的路灯自动控制装置的组成、性能、适用范围及工作原理,并给出了电路原理图和印制板图,文中给出了元件参数选择及制作方法,具有很强的节电实用意义。     

Modular Molecular Self‐Assembly for Diversified Chiroptical Systems

Bottom‐up multicomponent molecular self‐assembly is an efficient approach to fabricate and manipulate chiral nanostructures and their chiroptical activities such as the Cotton effect and circular polarized luminescence (CPL). However, the integrated coassembly suffers from spontaneous and inherent systematic pathway complexity with low yield and poor fidelity. Consequently, a rational design of chiral self‐assembled systems with more than two components remains a significant challenge. Herein, a modularized, ternary molecular self‐assembly strategy that generates chiroptically active materials at diverse hierarchical levels is reported. N‐terminated aromatic amino acids appended with binding sites for charge transfer and multiple hydrogen bonds undergo the evolution of supramolecular chirality with unique handedness and luminescent color, generating abundant CPL emission with high luminescence dissymmetry factor values in precisely controlled modalities. Ternary coassembly facilitates high‐water‐content hydrogel formation constituted by super‐helical nanostructures, demonstrating a helix to toroid topological transition. This discovery would shed light on developing complicated multicomponent systems in mimicking biological coassembly events.     

稳定性切换点法在时滞系统的鲁棒稳定性中的应用

讨论了一类参数与时滞相关的时滞系统的鲁棒稳定性.在"稳定性切换几何判据法"的基础上提出了"稳定性切换点法",使用该方法可得到相应方程零解稳定的参数变化区域.针对向日葵方程这一实际例子,利用文中所提出的方法并结合Maple软件作图可以容易地得到稳定性区域和不稳定性区域以及两区域的分界线、Hopf分岔点等;进一步通过对时滞...     

A UV‐Responsive Multifunctional Photoelectric Device Based on Discotic Columnar Nanostructures and Molecular Motors

Orientation control of ordered materials would not only produce new physical phenomenon but also facilitate the development of fancy devices. Discotic liquid crystals (DLCs) form 1D charge transport pathway by self‐organizing into columnar nanostructures via π–π stacking. However, controlling the electrical properties in such nanostructures with some direct and instant way is a formidable task for their high viscosity and insensitivity to external stimuli. Herein, the arbitrary control over electrical conductivity of such columnar nanostructures is achieved with UV light by incorporating DLCs with molecular motors. Highly ordered DLC microstripe arrays are generated on desired substrate through a capillary bridge dewetting strategy. The conductivity of the microstripes could be continuously modulated by 365 nm light due to the influence of molecular motion under UV irradiation on the electron orbital overlap of columnar nanostructures. This is so because the disorder degree of the DLC molecules is associated with the intensity of UV light and the doping concentration of molecular motors. Moreover, the device shows memory effect and reversible conductivity change. The DLC microstripe arrays are very promising for the applications in UV detectors, memory devices, optical switches, and so on.     

Optically Rewritable Transparent Liquid Crystal Displays Enabled by Light‐Driven Chiral Fluorescent Molecular Switches

Functional soft materials exhibiting distinct functionalities in response to a specific stimulus are highly desirable towards the fabrication of advanced devices with superior dynamic performances. Herein, two novel light‐driven chiral fluorescent molecular switches have been designed and synthesized that are able to exhibit unprecedented reversible Z/E photoisomerization behavior along with tunable fluorescence intensity in both isotropic and anisotropic media. Cholesteric liquid crystals fabricated using these new fluorescent molecular switches as chiral dopants exhibit reversible reflection color tuning spanning the visible and infrared region of the spectrum. Transparent display devices have been fabricated using both low chirality and high chirality cholesteric films that operate either exclusively in fluorescent mode or in both fluorescent and reflection mode, respectively. The dual mode display device employing short pitch cholesteric film is able to function on demand under all ambient light conditions including daylight and darkness with fast response and high resolution. Moreover, the proof‐of‐concept for a “remote‐writing board” using cholesteric films containing one of the light‐driven chiral fluorescent molecular switches with ease of fabrication and operation is disclosed herein. Such optically rewritable transparent display devices enabled by light‐driven chiral fluorescent molecular switches pave a new way for developing novel display technology under different lighting conditions.     

The role of aromaticity and the pi-conjugated framework in multiporphyrinic systems as single-molecule switches

A systematic analysis of electron-transport characteristics for monomer, dimer, and tetramer multiporphyrinic systems is presented, to provide a thorough understanding of the structural dependence of electron transport related to the aromatic nature of the contact structure. Theoretical investigation shows that the electron-transport characteristics can be controlled by manipulating the pi-conjugated framework in the multiporphyrinic systems through the arrangement of the inner hydrogen atoms. The designed pi-conjugated framework assigns the distinct aromaticity on the contact structure, and the large aromatic nature of the contact structure increases conductivity. The feature emerging from this study is that the aromaticity and pi-conjugated framework are important factors that control the electron-transport characteristics in molecular-scale electronic devices, such as single-molecule switches.