- 标题
- 摘要
- 关键词
- 实验方案
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A Visible-Light-Driven Molecular Motor Based on Pyrene
摘要： The aromatic core of an overcrowded alkene-based molecular motor is extended with the goal of inducing isomerization with visible light instead of harmful UV light. In our design, the common naphthalene moiety in the upper half of the motor is changed to pyrene. The photochemical and thermal isomerization processes are studied in detail using DFT calculations as well as NMR and UV/vis spectroscopy. Our studies confirm that extension of the π-system of the upper half successfully leads to a shift of the excitation wavelength into the visible region, while retaining proper rotary function.
关键词： Molecular Switches,Photochromism,Overcrowded Alkenes,Molecular Motors,Pyrene
更新于2025-09-23 15:23:52
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A UV-Responsive Multifunctional Photoelectric Device Based on Discotic Columnar Nanostructures and Molecular Motors
摘要： 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.
关键词： discotic liquid crystals,tunable conductivity,molecular motors,overcrowded alkenes,optical switches
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Multistage Interband Cascade Thermophotovoltaic Devices with ~0.2 eV Bandgap
摘要： Detection of defects in induction machine rotor bars for disassembled motors are required to evaluate machines considered for repair as well as fulfilling incremental quality assurance checks in the manufacture of new machines. Detection of rotor bar defects prior to motor assembly are critical in increasing repair efficiency and assuring the quality of newly manufactured machines. Many methods of detecting rotor bar defects in unassembled motors lack the sensitivity to find both major and minor defects in both cast and fabricated rotors along with additional deficiencies in quantifiable test results and arc-flash safety hazards. A process of direct magnetic field analysis can examine measurements from induced currents in a rotor separated from its stator yielding a high-resolution fingerprint of a rotor’s magnetic field. This process identifies both major and minor rotor bar defects in a repeatable and quantifiable manner appropriate for numerical evaluation without arc-flash safety hazards.
关键词： magnetic flux,ac motors,electromagnetic measurements,induction motors,rotors,AC machines
更新于2025-09-23 15:21:01
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - VIS-NIR GeSi Photodetector with Voltage Tunable Spectral Response
摘要： An innovative double-sided tubular linear induction motor is presented, and its optimal design in terms of thrust force is discussed. A dedicated semi-analytical model of the device is developed allowing for fast and accurate evaluation of all the electromechanic quantities in the device, including the thrust force, back-electromotive force, distribution of the induced current, and average magnetic flux density in the teeth. This provides a basis for the design optimization, which has been performed by a novel evolutionary algorithm based on the self-organizing maps. Using the semi-analytical formulation, the characterization of the machine is greatly facilitated, thus allowing a fast evaluation of the cost function and design constraints. Finally, the obtained optimal design is validated by comparison with finite elements method analysis.
关键词： linear motors,Electromagnetic analysis,induction motors,induction accelerators,optimization methods
更新于2025-09-23 15:19:57
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Encyclopedia of Automotive Engineering || Body and Lighting ECU (Key-less Entry, Sonar, HID, LED Usage for Lamps)
摘要： The purpose of body controls is to improve aspects of vehicle performance, such as comfort, usability, safety, theft prevention, serviceability, and the like. This is accomplished by controlling the output of motors, lamps, and the like, based on inputs mainly from switches and sensors. Table 1 lists some examples of products and functions that aim to improve these aspects of performance. Many of these body control products are designed to enhance the perceived value of the vehicle and to create an appealing impression to the user. For this reason, these controls were conventionally installed mainly in luxury vehicles. In recent years, however, technological innovations have reduced costs to the level where more and more have become available in mass-market vehicles.
关键词： Body controls,switches,safety,theft prevention,usability,vehicle performance,comfort,sensors,serviceability,lamps,motors
更新于2025-09-23 15:19:57
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Visible-Light-Driven Rotation of Molecular Motors in a Dual-Function Metala??Organic Framework Enabled by Energy Transfer
摘要： The visible-light driven rotation of an overcrowded-alkene based molecular motor strut in a dual-function metal-organic framework (MOF) is reported. Two types of functional linkers, a palladium-porphyrin photosensitizer and a bispyridine derived molecular motor were used to construct the framework capable of harvesting low-energy green light to power the rotary motion. The molecular motor was introduced in the framework using the post synthetic solvent assisted linker exchange (SALE) method and the structure of the material was confirmed by powder (PXRD) and single crystal X-ray (SC-XRD) diffraction. The large decrease in the phosphorescence lifetime and intensity of the porphyrin in the MOFs upon introduction of the molecular motor pillars confirms efficient triplet-to-triplet energy transfer between the porphyrin linkers and molecular motor. Near infrared Raman spectroscopy revealed that the visible light driven rotation of the molecular motor proceeds in the solid state at rates similar to those observed in solution.
关键词： molecular motors,metal-organic frameworks,molecular machines,energy transfer
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - High Power Indium Phosphide Photonic Integrated Circuit for Pulse Position Modulation Free Space Optical Communications
摘要： Detection of defects in induction machine rotor bars for disassembled motors are required to evaluate machines considered for repair as well as fulfilling incremental quality assurance checks in the manufacture of new machines. Detection of rotor bar defects prior to motor assembly are critical in increasing repair efficiency and assuring the quality of newly manufactured machines. Many methods of detecting rotor bar defects in unassembled motors lack the sensitivity to find both major and minor defects in both cast and fabricated rotors along with additional deficiencies in quantifiable test results and arc-flash safety hazards. A process of direct magnetic field analysis can examine measurements from induced currents in a rotor separated from its stator yielding a high-resolution fingerprint of a rotor’s magnetic field. This process identifies both major and minor rotor bar defects in a repeatable and quantifiable manner appropriate for numerical evaluation without arc-flash safety hazards.
关键词： magnetic flux,ac motors,electromagnetic measurements,induction motors,rotors,AC machines
更新于2025-09-19 17:13:59
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[IEEE 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Dhaka, Bangladesh (2019.9.26-2019.9.28)] 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Analysis of Photovoltaic Characteristics of Carbon Nanotube Incorporated Perovskite Solar Cell with CNT Chirality Variation
摘要： In the advanced manufacturing industry, planar switched reluctance motors (PSRMs) have proved to be a promising candidate due to their advantages of high precision, low cost, low heat loss, and ease of manufacture. However, their inverse force function, which provides vital phase current command for precise motion, is highly nonlinear and hard to be accurately modeled. This paper proposes a novel inverse force function using sparse least squares support vector machines (LS-SVMs) to achieve nonlinear modeling for precise motion of a PSRM. The required training and testing sets of sparse LS-SVMs are ?rst obtained from experimental measurement. A sparse LS-SVMs regression is further developed using training set to accurately model the inverse force function. Accordingly, the function is tested via the testing set to assess its feasibility. Finally, the proposed approach is applied to the PSRM system with dSPACE controller for trajectory tracking, and its effectiveness and superior performance are veri?ed through experimental results.
关键词： Inverse force function,least squares support vector machines (LS-SVMs),phase current estimation,nonlinear modeling,planar switched reluctance motors (PSRMs)
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Topological and Geometrical Effects in the Bulk Hall Response of Driven-Dissipative Photonic Lattices
摘要： In the advanced manufacturing industry, planar switched reluctance motors (PSRMs) have proved to be a promising candidate due to their advantages of high precision, low cost, low heat loss, and ease of manufacture. However, their inverse force function, which provides vital phase current command for precise motion, is highly nonlinear and hard to be accurately modeled. This paper proposes a novel inverse force function using sparse least squares support vector machines (LS-SVMs) to achieve nonlinear modeling for precise motion of a PSRM. The required training and testing sets of sparse LS-SVMs are ?rst obtained from experimental measurement. A sparse LS-SVMs regression is further developed using training set to accurately model the inverse force function. Accordingly, the function is tested via the testing set to assess its feasibility. Finally, the proposed approach is applied to the PSRM system with dSPACE controller for trajectory tracking, and its effectiveness and superior performance are veri?ed through experimental results.
关键词： Inverse force function,least squares support vector machines (LS-SVMs),phase current estimation,nonlinear modeling,planar switched reluctance motors (PSRMs)
更新于2025-09-19 17:13:59
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Lighta??Driven Liquid Crystalline Networks and Soft Actuators with Degreea??ofa??Freedoma??Controlled Molecular Motors
摘要： Design and fabrication of photomechanical soft actuators has attracted intense scientific interest because of their potential in the manufacture of untethered intelligent soft robots and advanced functional devices. Trifunctional and monofunctional polymerizable molecular motors are judiciously designed and synthesized. Novel light-driven liquid crystalline networks (LCN) are prepared by crosslinking overcrowded-alkene-based molecular motors with different degrees of freedom into the anisotropic LCN. The photoisomerization and thermal helix inversion of light-driven molecular motors are reversible when only the upper part of the molecular motor is linked to the network, endowing the LCN film with remarkable photoactive performance. However, photochemical geometric change of the light-driven molecular motor does not work after crosslinking both the upper and lower part of the motor by polymer chains. Interestingly, it is found that the fastened motor can transfer the light energy into localized heat instead of performing photoisomerization. The light-driven molecular-motor-based LCN soft actuators are demonstrated to function as a grasping hand, where the continuous motions of grasping, moving, lifting, and releasing an object are successfully achieved. This work may provide inspiration to the preparation of next-generation photoactive advanced functional materials toward their wide applications in the areas of photonics, optoelectronics, soft robotics, and beyond.
关键词： liquid crystalline networks,soft robotics,light-driven systems,molecular motors
更新于2025-09-19 17:13:59