High-Altitude Long-Endurance(HALE)solar-powered Unmanned Aircraft Vehicles(UAVs)can utilize solar energy as power source and maintain extremely long cruise endurance,which has attracted extensive attentions from resea...High-Altitude Long-Endurance(HALE)solar-powered Unmanned Aircraft Vehicles(UAVs)can utilize solar energy as power source and maintain extremely long cruise endurance,which has attracted extensive attentions from researchers.Trajectory optimization is a promising way to achieve superior flight time because of the finite solar energy absorbed in a day.In this work,a method of trajectory optimization and guidance for HALE solar-powered aircraft based on a Reinforcement Learning(RL)framework is introduced.According to flight and environment information,a neural network controller outputs commands of thrust,attack angle,and bank angle to realize an autonomous flight based on energy maximization.The validity of the proposed method was evaluated in a 5-km radius area in simulation,and results have shown that after one day-night cycle,the battery energy of the RL-controller was improved by 31%and 17%compared with those of a Steady-State(SS)strategy with a constant speed and a constant altitude and a kind of statemachine strategy,respectively.In addition,results of an uninterrupted flight test have shown that the endurance of the RL controller was longer than those of the control cases.展开更多
In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the dev...In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the devices.Herein,we have investigated singlet excited state relaxation dynamics and their triplet exciton lifetimes of two thiophene-coupled perylene diimides(PDI)dyads(2 PDI-Th and fused-2 PDI-Th),in order to provide a unique explanation in depth on their different performances in OSC devices.From the transient absorption(TA)spectra,the singlet excitons of 2 PDI-Th form excimers in the time scale of 1.5 ps.Then the excimers go into the triplet state via intersystem crossing(ISC).In fused-2 PDI-Th,triplet excitons are generated directly from the singlet excited excitons via the efficient ISC.Density functional theory(DFT)calculations further support the formation of excimers.DFT results indicate that 2 PDI-Th exhibits an H-typed molecular configuration which is beneficial to form the excimers,while fused-2 PDITh gives a twisted X-shaped configuration in the optimized ground and excited state.In steady-state emission spectra,2 PDI-Th shows abroad and featureless spectral characteristics of the excimers with a decay time of 840 ps,which is much shorter than those of PDI(5.5 ns)and fused-2 PDI-Th(3.3 ns).The triplet lifetime(67 ms)of fused-2 PDI-Th is factor of 3 longer than that of 2 PDI-Th(22 ms).These results demonstrate that ring-fused structure is an efficient strategy to eliminate excimer formation and prolong the lifetime of triplet excitons,which provides a new insight for design of optoelectronic molecules for high efficiency organic solar cells.展开更多
Developing natural nano-platforms with high biocompatibility and natural targeting ability represents great significance for drug delivery.High-density lipoprotein(HDL),a natural lipid-protein complex,plays important ...Developing natural nano-platforms with high biocompatibility and natural targeting ability represents great significance for drug delivery.High-density lipoprotein(HDL),a natural lipid-protein complex,plays important roles in physiological activities,particularly in reverse cholesterol transport(RCT)and be closely associated with atherosclerotic cardiovascular diseases.Recent studies have demonstrated that HDLs have the potential to serve as ideal drug carriers.Recombinant HDLs(r HDLs)have been used to encapsulate substances such as small interfering RNA(siRNA),drugs,and contrast agents,fully utilizing the biocompatibility and targeting ability of r HDL in the body and providing new strategies for drug delivery and disease treatment.In this review,we discussed in detail the basic principles of HDL as a drug delivery system,the mechanisms of targeted drug delivery,and several methods for preparing HDL nanoparticles.Afterward,we comprehensively reviewed the applications of HDL as a drug carrier in cardiovascular diseases,cancer treatment(such as glioblastoma,breast cancer,hepatocellular carcinoma and urologic cancers)and some other fields.Finally,we reviewed the therapeutic effects and safety of HDL nanoparticles in clinical studies.Through a review and summary of these research advances,we aim to fully understand the potential of HDL as a drug carrier in clinical applications,providing valuable references and guidance for future research and expedites the translational application of HDL as drug carriers.展开更多
This Letter shows the Vernier effect based on two segments of PANDA polarization maintaining fiber(PMF),whose lengths are 28 and 23 cm, respectively. The two PMFs are spliced together, and the angle between the fast a...This Letter shows the Vernier effect based on two segments of PANDA polarization maintaining fiber(PMF),whose lengths are 28 and 23 cm, respectively. The two PMFs are spliced together, and the angle between the fast axes is set to 45°. This cascaded PMF is inserted in a Sagnac loop to form an interferometer that can generate the Vernier effect. The spectrum consists of finesse fringe and envelope and realizes simultaneous measurement of strain and temperature. The envelope can provide strain and temperature sensitivities of 58.0 pm/με and -1.05 nm/℃. The finesse fringe provides sensitivities of 5.9 pm/με and -1.36 nm/℃.展开更多
The evolution of soliton molecules emphasizes the complex soliton dynamics akin to matter molecules.Beyond the simplest soliton molecule-a soliton pair constituted by two bound pulses-soliton molecules with more const...The evolution of soliton molecules emphasizes the complex soliton dynamics akin to matter molecules.Beyond the simplest soliton molecule-a soliton pair constituted by two bound pulses-soliton molecules with more constituents have more degrees of freedom because of the temporal pulse separations and relative phases.Here we detailedly characterize the transient dynamics of soliton triplets in fiber lasers by using the dispersive Fourier transform measurement.A particular form of leading,central,and tailing pulses is constructed to shed new light on more intriguing scenarios and fuel the molecular analogy.Especially the vibrating dynamics of the central and tailing pulses are captured near the regime of equally spaced soliton triplets,which is reminiscent of the recurrent timing jitters within multi-pulse structures.Further insights enable acess into a universal form of unequally spaced soliton triplets interpreted as 2+1 soliton molecules.Different binding strengths of intramo-lecular and intermolecular bonds are validated with respect to the diverse internal motions involved in this soliton triplet molcule.All these findings unveil the transient dynamics with more degrees of freedom as well as highlight the possible application for all-optical bit storage.展开更多
基金Foundation of the Special Research Assistant of Chinese Academy of Sciences(No.E0290A0301)。
文摘High-Altitude Long-Endurance(HALE)solar-powered Unmanned Aircraft Vehicles(UAVs)can utilize solar energy as power source and maintain extremely long cruise endurance,which has attracted extensive attentions from researchers.Trajectory optimization is a promising way to achieve superior flight time because of the finite solar energy absorbed in a day.In this work,a method of trajectory optimization and guidance for HALE solar-powered aircraft based on a Reinforcement Learning(RL)framework is introduced.According to flight and environment information,a neural network controller outputs commands of thrust,attack angle,and bank angle to realize an autonomous flight based on energy maximization.The validity of the proposed method was evaluated in a 5-km radius area in simulation,and results have shown that after one day-night cycle,the battery energy of the RL-controller was improved by 31%and 17%compared with those of a Steady-State(SS)strategy with a constant speed and a constant altitude and a kind of statemachine strategy,respectively.In addition,results of an uninterrupted flight test have shown that the endurance of the RL controller was longer than those of the control cases.
基金the National Natural Science Foundation of China(Nos.21421005,21576040,21776037 and 21875027)the Fundamental Research Funds for the Central Universities(No.DUT19LK05)Supercomputing Center of Dalian University of Technology。
文摘In the active layer of organic solar cells(OSCs),the lifetime of triplet excitons is one of the decisive factors in the diffusion length and therefore has important impact on the power conversion efficiency of the devices.Herein,we have investigated singlet excited state relaxation dynamics and their triplet exciton lifetimes of two thiophene-coupled perylene diimides(PDI)dyads(2 PDI-Th and fused-2 PDI-Th),in order to provide a unique explanation in depth on their different performances in OSC devices.From the transient absorption(TA)spectra,the singlet excitons of 2 PDI-Th form excimers in the time scale of 1.5 ps.Then the excimers go into the triplet state via intersystem crossing(ISC).In fused-2 PDI-Th,triplet excitons are generated directly from the singlet excited excitons via the efficient ISC.Density functional theory(DFT)calculations further support the formation of excimers.DFT results indicate that 2 PDI-Th exhibits an H-typed molecular configuration which is beneficial to form the excimers,while fused-2 PDITh gives a twisted X-shaped configuration in the optimized ground and excited state.In steady-state emission spectra,2 PDI-Th shows abroad and featureless spectral characteristics of the excimers with a decay time of 840 ps,which is much shorter than those of PDI(5.5 ns)and fused-2 PDI-Th(3.3 ns).The triplet lifetime(67 ms)of fused-2 PDI-Th is factor of 3 longer than that of 2 PDI-Th(22 ms).These results demonstrate that ring-fused structure is an efficient strategy to eliminate excimer formation and prolong the lifetime of triplet excitons,which provides a new insight for design of optoelectronic molecules for high efficiency organic solar cells.
基金the National Natural Science Foundation of China(Nos.52273128,82003450)the Natural Science Foundation of Guangdong Province(No.2022A1515220048)+2 种基金the Natural Science Foundation of Guizhou Province(Nos.Guizhou Province-ZK[2022]General 300,Guizhou Province-ZK[2023]General 244)the Xiangshan Talented Scientific Research Foundation of Zhuhai People’s Hospital(No.2023XSYC-01)Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment(No.2021B1212040004)。
文摘Developing natural nano-platforms with high biocompatibility and natural targeting ability represents great significance for drug delivery.High-density lipoprotein(HDL),a natural lipid-protein complex,plays important roles in physiological activities,particularly in reverse cholesterol transport(RCT)and be closely associated with atherosclerotic cardiovascular diseases.Recent studies have demonstrated that HDLs have the potential to serve as ideal drug carriers.Recombinant HDLs(r HDLs)have been used to encapsulate substances such as small interfering RNA(siRNA),drugs,and contrast agents,fully utilizing the biocompatibility and targeting ability of r HDL in the body and providing new strategies for drug delivery and disease treatment.In this review,we discussed in detail the basic principles of HDL as a drug delivery system,the mechanisms of targeted drug delivery,and several methods for preparing HDL nanoparticles.Afterward,we comprehensively reviewed the applications of HDL as a drug carrier in cardiovascular diseases,cancer treatment(such as glioblastoma,breast cancer,hepatocellular carcinoma and urologic cancers)and some other fields.Finally,we reviewed the therapeutic effects and safety of HDL nanoparticles in clinical studies.Through a review and summary of these research advances,we aim to fully understand the potential of HDL as a drug carrier in clinical applications,providing valuable references and guidance for future research and expedites the translational application of HDL as drug carriers.
基金supported by the National Key R&D Program of China(No.2018YFF01011800)the National Natural Science Foundation of China(No.61775070)
文摘This Letter shows the Vernier effect based on two segments of PANDA polarization maintaining fiber(PMF),whose lengths are 28 and 23 cm, respectively. The two PMFs are spliced together, and the angle between the fast axes is set to 45°. This cascaded PMF is inserted in a Sagnac loop to form an interferometer that can generate the Vernier effect. The spectrum consists of finesse fringe and envelope and realizes simultaneous measurement of strain and temperature. The envelope can provide strain and temperature sensitivities of 58.0 pm/με and -1.05 nm/℃. The finesse fringe provides sensitivities of 5.9 pm/με and -1.36 nm/℃.
基金National Natural Science Foundation of China(61775067,61775072)Ministry of Education-Singapore(MOE2019-T1-001-111)National Research Foundation Singapore(NRF-CRP-18-2017-02).
文摘The evolution of soliton molecules emphasizes the complex soliton dynamics akin to matter molecules.Beyond the simplest soliton molecule-a soliton pair constituted by two bound pulses-soliton molecules with more constituents have more degrees of freedom because of the temporal pulse separations and relative phases.Here we detailedly characterize the transient dynamics of soliton triplets in fiber lasers by using the dispersive Fourier transform measurement.A particular form of leading,central,and tailing pulses is constructed to shed new light on more intriguing scenarios and fuel the molecular analogy.Especially the vibrating dynamics of the central and tailing pulses are captured near the regime of equally spaced soliton triplets,which is reminiscent of the recurrent timing jitters within multi-pulse structures.Further insights enable acess into a universal form of unequally spaced soliton triplets interpreted as 2+1 soliton molecules.Different binding strengths of intramo-lecular and intermolecular bonds are validated with respect to the diverse internal motions involved in this soliton triplet molcule.All these findings unveil the transient dynamics with more degrees of freedom as well as highlight the possible application for all-optical bit storage.
