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

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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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BIOLOGICAL INVASION PROBLEm WITH FREE BOUNDARY NONLOCAL DIFFUSION EQUATION

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数学杂志 2025年第1期45卷 48-56页

作者： HE Yu-rong ZHANG ya-rong School of Science Xi'an University of Architecture and TechnologyXi'an 710055China Xi'an Special Equipment Inspection Institute Xi'an 710065China School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China

In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological ***,the right free boundary is added to the equation with logistic ***,the existence and uniqueness of local solutions are proved by the Sobolev embedding theorem and the comparison ***,according to the relevant research data and contents of red fire ants,the diffusion area and nest number of red fire ants were simulated without external *** paper mainly simulates the early diffusion process of red fire *** the early diffusion stage,red fire ants grow slowly and then spread over a large area after reaching a certain number.

关键词： Free boundary biological invasion differential equation

Effect of diluents on the extraction of praseodymium and samarium by Cyanex 923 from acidic nitrate medium

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Journal of Rare Earths 2010年第2期28卷 215-220页

作者： ya El-Nadi Hot Laboratories Centre Atomic Energy Authority(Egypt)

The solvent extraction of Pr(Ⅲ) and Sm(Ⅲ) with trialkyl phosphine oxide(Cyanex 923) in chloroform,carbon tetrachloride,n-octane,cyclohexane,1,2-dichloroethane,benzene,toluene,xylene and nitrobenzene from acidic nitrate medium was *** the basis of slope analysis data,the composition of the extracted species was determined as(m(NO3)3?2CY923),CY923 refers to Cyanex *** values of the equilibrium constants and the separation factors were *** effect of the diluents on the metal extracti...

关键词： extraction diluents praseodymium samarium Cyanex 923 rare earths

Crashworthiness performance of hybrid kenaf/glass fiber reinforced epoxy tube on winding orientation effect under quasi-static compression load

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Defence Technology（防务技术） 2020年第5期16卷 1051-1061页

作者： A.B.m.Supian S.m.Sapuan m.Y.m.Zuhri E.S.Zainudin H.H.ya Advanced Engineering materials and Composites Research Centre Department of Mechanical and Manufacturing EngineeringUniversiti Putra Malaysia43400UPM SerdangSelangorMalaysia Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products(INTROP)Universiti Putra Malaysia43400UPM SerdangSelangorMalaysia Department of mechanical Engineering Universiti Teknologi Petronas32610Seri IskandarPerakMalaysia

This research was aimed to study the effect winding orientation on the crashworthiness performance of hybrid *** specimens tested under quasi-static compression load involve of three winding parameters(q?30,45and 70)of hybrid kenaf/glass fiber reinforced epoxy and glass fiber reinforced epoxy as contrast *** automated filament winding technique has been used in fabrication of hybrid and non-hybrid composite tube and crashworthiness performance was investigated *** effects of winding orientation on energy absorption capabilities and crashworthiness characteristic were investigated through quasi-static compression load and the result are compared with the glass fiber composite tube to justify the capability of hybrid natural/synthetic as energy absorption *** samples proved to enhancing the progressive crushing capability as combination of local buckling,delaminate and brittle fracturing as progressive crushing *** the view of winding orientation aspect,the results of high winding orientation of hybrid composite tube elevated the crush load efficiency,specific energy absorption and energy absorption capability compared to glass composite tube(GFRP).The hybrid kenaf/glass composite tube with high winding orientation showed the best winding orientation to enhance the energy absorber characteristics as energy absorption application.

关键词： composite laminate winding

Fully enclosed hybrid electromagnetic-triboelectric nanogenerator to scavenge vibrational energy

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Nano Research 2016年第8期9卷 2226-2233页

作者： Ting Quan ya yang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology Beijing 100083 China

We propose a fully enclosed hybrid nanogenerator consisting of five elec- tromagnetic generators （EmGs） and four triboelectric nanogenerators （TENGs）. Under a vibration frequency of 15.5 Hz, one TENG can deliver a high output voltage of approximately 24 V and a low output current of approximately 24 μA, whereas one EmG can deliver a low output voltage of approximately 0.8 V and a high output current of approximately 0.5 mA. By integrating five rectified EmGs in series and four rectified TENGs in parallel, the hybrid nanogenerator can be used to charge a home-made Li-ion battery from 1 to 1.9 V in 6.3 h. By using the hybrid nanogenerator to scavenge the vibrational energy produced by human hands, a temperature-humidity sensor can be sustainably powered by the nanogenerator, which is capable of charging the 200 ~F system power capacitor from 0 to 2 V in 15 s, and sustainably power the sensor in 29 s.

关键词： hybrid nanogenerator electromagnetic triboelectric vibration energy Li-ion battery

Linear-grating hybridized electromagnetic-triboelectric nanogenerator for sustainably powering portable electronics

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Nano Research 2016年第4期9卷 974-984页

作者： Kewei Zhang ya yang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 China

Utilizing a nanogenerator to scavenge mechanical energy from our living environment is an effective method to solve the power source issue of portable electronics. We report a linear-grating hybridized electromagnetic-triboelectric nanogenerator for scavenging the mechanical energy generated from sliding motions to sustainably power certain portable electronics. The hybridized nano- generator consists of a slider and a stator in the structural design, and possesses a 66-segment triboelectric nanogenerator （TENG） and a 9-segment electromagnetic generator （EmG） in the functional design. At a sliding acceleration of 20 m/s2 the hybridized nanogenerator can deliver maximum powers of 102.8 mW for the TENG at a loading resistance of 0.4 mr2 and 103.3 mW for the EmG at a loading resistance of 6 kf2. With an optimal hybridized combination of the TENG with a transformer and the EmG with a power management circuit, a 10 mF capacitor can be easily charged to 2.8 V in 20 s. A packaged hybridized nanogenerator with a light weight of 140 g and small dimensions of 12 cm× 4 cm× 1.6 cm excels in scavenging low-frequency sliding energy to sustainably power portable electronics.

关键词： energy harvesting hybridized nanogenerator conjunction operation sliding motion self-powered electronics

Safe navigation of quadrotors with jerk limited trajectory

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Frontiers of Information Technology & Electronic Engineering 2019年第1期20卷 107-119页

作者： Shu-peng LAI meng-lu LAN ya-xuan LI Ben m.CHEN Department of Electrical and Computer Engineering National University of Singapore Graduate School for Integrative Science & Engineering National University of Singapore School of Control Science and Engineering Shandong University Department of mechanical and Automation Engineering Chinese University of Hong Kong

many aerial applications require unmanned aerial systems operate in safe zones because of the presence of obstacles or security regulations. It is a non-trivial task to generate a smooth trajectory satisfying both dynamic constraints and motion limits of the unmanned vehicles while being inside the safe zones. Then the task becomes even more challenging for real-time applications, for which computational efficiency is crucial. In this study, we present a safe flying corridor navigation method, which combines jerk limited trajectories with an efficient testing method to update the position setpoints in real time. Trajectories are generated online and incrementally with a cycle time smaller than 10 μs, which is exceptionally suitable for vehicles with limited onboard computational capability. Safe zones are represented with multiple interconnected bounding boxes which can be arbitrarily *** jerk limited trajectory generation algorithm has been extended to cover the cases with asymmetrical motion limits. The proposed method has been successfully tested and verified in flight simulations and actual experiments.

关键词： Quadrotor Unmanned aerial vehicle motion planning

Asymmetric biotic interchange across the Bering land bridge between Eurasia and North america

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National Science Review 2019年第4期6卷 739-745页

作者： Dechun Jiang Sebastian Klaus ya-Ping Zhang David m.Hillis Jia-Tang Li CAS Key Laboratory of mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of Biology Chinese Academy of Sciences Department of Ecology and Evolution J.W.Goethe University State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences CAS Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Department of Integrative Biology and Biodiversity Center University of Texas at Austin

The exchange of biotas between Eurasia and North america across the Bering land bridge had a major impact on ecosystems of both continents throughout the Cenozoic. This exchange has received particular attention regarding placental mammals dispersing into the americas, including humans after the last glacial period, and also as an explanation for the disjunct distribution of related seed plants in eastern Asia and eastern North america. Here, we investigate bi-directional dispersal across the Bering land bridge from estimates of dispersal events based on time-calibrated phylogenies of a broad range of plant, fungus and animal taxa. We reveal a long-lasting phase of asymmetrical biotic interchange, with a peak of dispersal from Asia into North america during the late Oligocene warming(26–24 ma), when dispersal in the opposite direction was greatly decreased. Influx from North america into Asia was lower than in the opposite direction throughout the Cenozoic, but with peak rates of dispersal at the end of the Eocene(40–34 ma)and again in the early to middle miocene(16–14 ma). The strong association between dispersal patterns and environmental changes suggests that plants, fungi and animals have likely dispersed from stable to perturbed environments of North america and Eurasia throughout the Cenozoic.

关键词： multiple taxa biogeography Bering land bridge Cenozoic

Abundant Symmetries and Exact Compacton—Like Structures in the Two—Parameter Family of the Estevez—mansfield—Clarkson Equations

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Communications in Theoretical Physics 2002年第1期37卷 27-34页

作者： yaNZhen－ya DepartmentofAppliedmathematics DalianUniversityofTechnologyDalian116024China

The two-parameter family of Estevez-mansfield-Clarkson equations with fully nonlinear dispersion (called E(m, n) equations), (uzm)zzr + γ(unzur)z + urr = 0 which is a generalized model of the integrable Estevez-mansfieldClarkson equation u + γ(uzuzr +uzzur) +urr = 0, is presented. Five types of symmetries of the E(m, n) equation are obtained by making use of the direct reduction method. Using these obtained reductions and some simple tranaformations,we obtain the solitary-like wave solutions of E(1, n) equation. In addition, we also find the compacton solutions (which are solitary waves with the property that after colliding with other compacton solutions, they reemerge with the same coherent shape) orE(3, 2) equation and E(m, m- 1) for its potentials, say, uz, and compacton-like solutions of E(m, m- 1)equations, respectively. Whether there exist compacton-like solutions of the other E(m, n) equation with m ≠ n + 1 is still an open problem.

关键词：非线性方程非线性色散类孤子波解