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Double [5]carbohelicene: facile synthesis, chiroptical properties,isomerization study, and lasing application

Science China Chemistry 2025年第1期 233-240页

作者： Peipei Liu Yantong Li Meng-Xiang Wu Hao Kang Xiao-Li Zhao Lin Xu Linlin Liu Xiaodong Li Junfeng Fang Zhiwei Fang Ya Cheng Hai-Bo Yang Huakang Yu Xueliang Shi State key laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University School of Physics and Optoelectronics South China University of Technology Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology School of Physics and electronic Science Engineering Research Center of Nanophotonics & Advanced Instrument Ministry of EducationEast China Normal University State key laboratory of Precision Spectroscopy School of Physics and Electronic Science East China Normal University

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double[5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by Xray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase highperformance liquid chromatography（HPLC）, and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 m J cm-2. We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

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Far-Field Pattern Tolerance Analysis of Reflector Antenna with Random or System Error Based on Interval Arithmetic

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Chinese Journal of electronics 2018年第3期27卷 641-647页

作者： LI Peng LI Na XU Wanye WANG Wei key laboratory of electronic equipment Structure design Ministry of Education Xidian University

A novel analytic approach for the research of effect on electromagnetic performance of reflector antennas with deformation, including random processing error and system error caused by external loads(such as wind,gravity, and solar radiation), in panels of the reflector surface is proposed. The deformations are modeled as error intervals, and their impact on the electromagnetic performance, including radiation power pattern and some main electromagnetic characteristics(such as side lobe level,peak power, and half-power beamwidth), are efficiently estimated by Interval analysis(IA). The closed-form equations indicate the relationship between the error interval and the bounds(upper and lower bounds) of the radiated power pattern interval by exploiting the rules of interval arithmetic. Two kinds of surface errors(random and system error) and two shapes of deformation area(bump-like and sector) are taken into account in the numerical examples to assess the validation and effectiveness of the proposed approach. The results of the examples show that the proposed IA-based approach has great capability and effectiveness regarding the traditional statistical method(such as Monte-Carlo method).

关键词： Reflector antenna Interval analysis Random error System error Power pattern

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Effect of Surface Roughness in Micro-nano Scale on Slotted Waveguide Arrays in Ku-band

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 595-603页

作者： Na LI Peng LI Liwei SONG key laboratory of electronic equipment structure design of ministry of education xidian universityXi'an 710071China

Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and efficiency of the SWA in Ku-band. Firstly, the roughness is simulated using the electromechanical coupled（EC） model. The relationship between roughness and the antenna＇s radiation properties is obtained. For verification, an antenna proto- type is manufactured and tested, and the simulation method is introduced. According to the prototype, a contrasting experiment dealing with the flatness of the radiating plane is conducted to test the simulation method. The advantage of the EC model is validated by comparisons of the EC model and two classical roughness models （sine wave and fractal function）, which shows that the EC model gives a more accurate description model for roughness, the maxi- mum error is 13%. The existence of roughness strongly broadens the beamwidth and raises the side-lobe level of SWA, which is 1.2 times greater than the ideal antenna. In addition, effect of the EC model＇s evaluation indices is investigated, the most affected scale of the roughness is found, which is 1/10 of the working wavelength. The proposed research provides the instruction for antenna designing and manufacturing.

关键词： Slotted waveguide arrays - Roughness model Micro/nano-scale Amplitude and phase errors Radiationcharacteristics

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Coupling Modeling for Functional Surface of electronic equipment

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 497-499页

作者： Baoyan DUAN Congsi WANG Wei WANG key laboratory of electronic equipment structure design of ministry of education xidian universityXi'an 710071China

High performance electromechanical equipment is widely used in various fields, such as national defense, industry and so on [ 1]. In addition, the technical level of high performance electromechanical equipment is the... 详细信息

关键词： TT Coupling Modeling for Functional Surface of electronic equipment

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Type synthesis of 2-DoF rotational parallel mechanisms actuating the inter-satellite link antenna

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Chinese Journal of Aeronautics 2016年第6期29卷 1795-1805页

作者： Song Yimin Qi Yang Dong Gang Sun Tao key laboratory of Mechanism Theory and equipment design of ministry of education Tianjin University

This paper focuses on the type synthesis of two degree-of-freedom(2-DoF) rotational parallel mechanisms(RPMs) that would be applied as mechanisms actuating the inter-satellite link antenna. Based upon Lie group theory, two steps are necessary to synthesize 2-DoF RPMs except describing the continuous desired motions of the moving platform. They are respectively generation of required open-loop limbs between the fixed base and the moving platform and definition of assembly principles for these limbs. Firstly, all available displacement subgroups or submanifolds are obtained readily according to that the continuous motion of the moving platform is the intersection of those of all open-loop limbs. These subgroups or submanifolds are used to generate all the topology structures of limbs. By describing the characteristics of the displacement subgroups and submanifolds intuitively through employing simple geometrical symbols, their intersection and union operations can be carried out easily. Based on this, the assembly principles of two types are defined to synthesize all 2-DoF RPMs using obtained limbs. Finally, two novel categories of 2-DoF RPMs are provided by introducing a circular track and an articulated rotating platform,respectively. This work can lay the foundations for analysis and optimal design of 2-DoF RPMs that actuate the inter-satellite link antenna.

关键词： Articulated rotating platform Assembly principle Circular track Lie group theory Rotational parallel mechanism Tracking and data relay satellite Type synthesis

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A Reverse-design Strategy for the Track Error of the Qi Tai Telescope Based on Pointing Accuracy

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Engineering 2022年第6期8卷 209-216页

作者： Na Li Baoyan Duan Xiangyang Li Bin Zheng Jiang Wu key laboratory of electronic equipment Structure design Ministry of EducationXidian UniversityXi’an 710061China

The Qi Tai Telescope(QTT),which has a 110 m aperture,is planned to be the largest scale steerable tele-scope in the ***,the telescope’s repeated pointing accuracy error should be less than 2.5 arc seconds(arcsec);thus,the telescope structure must satisfy ultra-high precision *** this pur-suit,the present research envisages a reverse-design method for the track surface to reduce the difficulty of the telescope’s design and ***,the distribution characteristics of the test data for the track error were verified using the skewness coefficient and kurtosis coefficient *** to the distribution characteristics,the azimuth track error was simulated by a two-scale *** error of the long period and short amplitude was characterized as large-scale and described by a trigonometric function,while the short period and high amplitude error was characterized as small-scale and simulated by a fractal *** on the two-scale model,effect of the error on the pointing accuracy was ***,the relationship between the root mean square(RMS)of the track error and the RMS of the pointing accuracy error of the telescope was ***,the allowable RMS value of the track error was derived from the allowable pointing accuracy *** validate the effectiveness of the new design method,two typical radio telescopes(the Green Bank Telescope(GBT)and the Large Millimeter Telescope(LMT))were selected as experimental *** comparison,the theoretical calculated values of the pointing accuracy of the telescope were consistent with the measured values,with a maximum error of less than 10%.

关键词： Reverse design Track error Large radio telescope Two-scale model Pointing accuracy

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B-spline surface fitting and simplified GO/PO analysis of subreflector correction for large Cassegrain antenna distortion compensation

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Research in Astronomy and Astrophysics 2018年第7期18卷 53-62页

作者： You Ban Cong-Si Wang Shu-Fei Feng Wei Wang Bao-Yan Duan key laboratory of electronic equipment Structure design Ministry of Education School of Electromechanical Engineering Xidian University

The main surface of a large Cassegrain antenna consists of a large number of panels. There are inevitably random and systematic errors which will degrade the antenna pattern and limit its applicability when working at high frequencies. Correcting the subreflector surface is difficult to describe by a global expansion effectively with a small amount of data. This paper presents a simple and clear way for correcting the subreflector surface of a large Cassegrain antenna for achieving such compensation. The advantage of the method is that the geometrical optics （GO） analysis is extremely simplified by the concept of equivalent prime-focus paraboloid, and corrected deformations of the subreflector surface are determined by simple formulas which represent the relationship between distortions of the subreflector surface and phase of the main surface current. The final shape of the subreflector surface is represented by a B-spline surface. To obtain a satisfactory antenna pattern with the simplest subreflector surface, the optimal number of B-spline patches are searched by particle swarm optimization （PSO）. The shaping process is verified by compensating a 22-m Cassegrain antenna whose main reflector has 96 panels. The results are satisfactory and demonstrate the simplicity and effectiveness of the approach.

关键词： telescopes reflector antennas subreflector shaping compensation

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Two-step Structural design of Mesh Antennas for High Beam Pointing Accuracy

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 604-613页

作者： Shuxin ZHANG Jingli DU Wei WANG Xinghua ZHANG Yali ZONG key laboratory of electronic equipment Structure design of ministry of education Xidian University Qian Xuesen laboratory of Space Technology China Academy of Space Technology

A well-designed reflector surface with high beam pointing accuracy in electromagnetic performance is of practical significance to the space application of cable mesh reflector antennas. As for space requirements, cir- cular polarizations are widely used in spaceborne antennas, which usually lead to a beam shift for offset reflectors and influence the beam pointing accuracy. A two-step structural design procedure is proposed to overcome the beam squint phenomenon for high beam pointing accuracy design of circularly polarized offset cable mesh reflectors. A simple structural optimal design and an integrated structural electromagnetic optimization are combined to alleviate the beam squint effect of circular polarizations. It is imple- mented by cable pretension design and adjustment to shape the offset cable mesh surface. Besides, in order to increase the efficiency of integrated optimization, an update Broy- den-Fletcher-Goldfarb-Shanno （BFGS） Hessian matrix is employed in the optimization iteration with sequential quadratic programming. A circularly polarized offset cable mesh reflector is utilized to show the feasibility and effectiveness of the proposed procedure. A high beam pointing accuracy in order of 0.0001~ of electromagnetic performance is achieved.

关键词： Cable mesh reflector antennas Structuraldesign Beam squint Beam pointing accuracy

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Special Issue on Electromechanical Coupling design for electronic equipment

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 495-496页

作者： Bao Yan DUAN Jian Rong TAN key laboratory of electronic equipment Structure design of ministry of education Xidian University State key Lab of CAD&CG Zhejiang University

With the development of electronic equipment to high accuracy, high density, high frequency, and atrocious ser- vice environment, the functional surface in this type of equipment has increasingly serious problems,

关键词： In Special Issue on Electromechanical Coupling design for electronic equipment design

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The Establishment and Analysis of the Structural-Electromagnetic Coupling Model of the Electrostatically Controlled Deployable Membrane Antenna

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Chinese Journal of electronics 2024年第2期33卷 479-487页

作者： Shunji ZHANG Yongzhen GU Wang ZHONG Qinggang ZHANG Qingdao University of Science and Technology key laboratory of electronic equipment Structure design of ministry of education Xidian University

A new structural-electromagnetic coupling(SEC) analysis based on quadratic elements is proposed to solve the mismatch problem between structural elements and electromagnetic grids of the electrostatically controlled deployable membrane antenna(ECDMA). Firstly, the ECDMA reflector surface is meshed and redefined by a series of quadratic elements. Without grid transformation, the calculating formulas for the far-field pattern of ECDMA are derived by the physical-optics method. Then the structural deformation of ECDMA is analyzed and the far-field pattern calculating formulas including deformation errors are developed. Simulation and experiment results show that the quadratic elements are effective and efficient in SEC analysis of the ECDMA, moreover, the electromagnetic grid size demand and the grid discretization error are reduced greatly.

关键词： Couplings Electrodes Analytical models Deformation Electromagnetic fields Electromagnetics Optimization

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