Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibilit...Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibility to light-induced phase segregation(LIPS)limits efficiency and stability.In this work,we investigate the effect of three organic additives-4-cyclopentene-1,3-dione(CPD),maleimide(HPD),and 3,4-dibromo-1H-pyrrole-2,5(2H,5H)-dione(BrPD)-on LIPS in wide-bandgap CsPbIBr_(2)perovskite films.The additives form various chemical interactions,including coordination bonds,hydrogen bonds,and ionic bonds,with I^(-)and undercoordinated Pb^(2+)ions,among which BrPD has the strongest interaction.This interaction regulates crystallization and improves film morphology.The BrPD-modified films have the largest grain size and the highest light stability,suppressing LIPS,enhancing carrier transfer,and improving device performance.BrPD-modified CsPbIBr_(2)-based solar cells achieve a power conversion efficiency(PCE)of 11.34%,outperforming the control(8.96%)and other additives.Moreover,BrPDmodified devices show excellent stability,retaining 94%of their initial PCE after 60 min of continuous light exposure.This work highlights the potential of strategically selected organic additives to enhance the stability and performance of perovskite solar cells,offering valuable insights for the design of high-efficiency and long-lasting perovskite-based optoelectronic devices.展开更多
Light-induced conical intersections(LICIs)present a distinctive mechanism for nonadiabatic coupling,thereby facilitating ultrafast chemical reactions,including the indirect photodissociation of diatomic molecules.In c...Light-induced conical intersections(LICIs)present a distinctive mechanism for nonadiabatic coupling,thereby facilitating ultrafast chemical reactions,including the indirect photodissociation of diatomic molecules.In contrast to static conical intersections,LICIs are dynamically tunable,providing a pathway for precise control of molecular dissociation.In this study,we employ the time-dependent quantum wave packet method to investigate the dissociation dynamics of the OH molecule,focusing on its ground state X^(2)Πand repulsive state 1^(2)Σ~-.By varying laser field parameters(intensity,full width at half maximum(FWHM),and wavelength),we elucidate how nonadiabatic coupling governs selective dissociation channel control.Our findings reveal that the choice of initial vibrational states and the tailoring of laser conditions significantly influence dissociation pathways,providing theoretical insights into manipulating molecular dynamics via LICIs.These results provide a foundation for future experimental studies and the development of advanced molecular control techniques.展开更多
The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a t...The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a two-body system. Two cases are considered： （i） Starting from a ground state the evolution is induced by a sudden change of the laser field, and （ii） the evolution starting from a superposition state. Oscillating persistent spin-currents have been found. A set of formulae have been derived to describe the period and amplitude of the oscillation. Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams. In particular, it is predicted that movable stripes might emerge on the ring.展开更多
In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted...In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted-triangular LiNTF is found by scanning through finite element analysis(FEA).The surface charge density and stress value of the inverted-triangular LiNTF are both higher than those of the standard quartz tuning fork(QTF).In the lithium niobate-enhanced photoacoustic spectroscopy(LiNPAS)sensing system,the 2f peak and signal-to-noise ratio(SNR)of the inverted-triangular LiNTF are 7.41 times and 5.89 times those of the standard QTF,respectively.After forming acoustic standing wave field with the acoustic micro-resonator(AmR),the LiNPAS system achieves an SNR 56.16 times higher than without the AmR.Based on Allan variance analysis,the system achieves a minimum detection limit(MDL)of 7.25 ppb with an averaging time of 800 seconds.In the light-induced thermoelastic spectroscopy(LITES)sensing system,the 2f peak and SNR of the inverted-triangular LiNTF are 7.82 times and 6.03 times those of the standard QTF,respectively.When the averaging time reaches 100 s,the MDL of the system is found to be 25.78 ppb.展开更多
Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into...Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into the new β phase during the pulsed current-assisted aging process,and then the newly formed β phase is mainly transformed into the β_(t) phase,with occasional transition to new α_(p) phase,leading to a remarkable grain refinement,especially for the lamellarαs phases.In comparison to conventional aging treatment,the pulsed current-assisted aging approach achieves a significant enhancement in strength without degrading ductility,yielding an excellent mechanical property combination:a yield strength of 932 MPa,a tensile strength of 1042 MPa,and an elongation of 12.2%.It is primarily ascribed to the increased fraction of β_(t) phases,the obvious grain refinement effect,and the slip block effect induced by the multiple-variantαs colonies distributed within β_(t) phases.展开更多
This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper cons...This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters.展开更多
To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electric...To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.展开更多
Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potentia...Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.展开更多
To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distributio...To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distribution networks,this paper adopts a component sharing mechanism to propose a composite multi-port hybrid DC circuit breaker(CM-HCB)with DC power flow and fault current limitation abilities,as well as reduced component costs.The proposed CM-HCB topology enables the sharing of the main breaker branch(MB)and the energy dissipation branch,while the load commutation switches(LCSs)in the main branch are reused as power flow control components,enabling flexible regulation of power flow in multiple lines.Meanwhile,by reconstructing the current path during the fault process,the proposed CM-HCB can utilize the internal coupled inductor to limit the current rise rate at the initial stage of the fault,significantly reducing the requirement for breaking current.A detailed study on the topological structure,steady-state power flow regulation mechanism,transient fault isolation mechanism,control strategy and characteristic analysis of the proposed CM-HCB is presented.Then,a Matlab/Simulink-based meshed three-terminal DC grid simulation platform with the proposed CM-HCB is built.The results indicate that the proposed CM-HCB can not only achieve flexible power flow control during steady-state operation,but also obtain current rise limitation and fault isolation abilities under short-circuit fault conditions,verifying its correctness and effectiveness.Finally,a comparative economic analysis is conducted between the proposed CM-HCB and the other two existing solutions,confirming that its component sharing mechanism can significantly reduce the number of components,lower system costs,and improve component utilization.展开更多
Light induced changes in a-Si∶H films are investigated by transient photoconductivity.The transient photoconductivity decay data can neither be fit well by common power-law for transient photocurrent in amorphous sem...Light induced changes in a-Si∶H films are investigated by transient photoconductivity.The transient photoconductivity decay data can neither be fit well by common power-law for transient photocurrent in amorphous semiconductors,nor by stretched exponential rule for transient decay from the steady state in photoconductivity.Instead,the data are fit fairly well with a sum of two exponential functions.The results show that the long time decay is governed by deep traps rather than band tail states,and two different traps locating separately at 0.52 and 0.59eV below E _c are responsible for the two exponential functions.They are designated as negatively charged dangling bond D - centers.The light-induced changes in photoconductivity are attributed mainly to the decrease in electron lifetime caused by the increase of recombination centers after light soaking.展开更多
We found an ultraviolet （UV）-light induced formation of biphenyl and sodium benzoate from benzene and sodium carbonate. The reaction happens in the interface of benzene and aqueous solution at the room temperature. ...We found an ultraviolet （UV）-light induced formation of biphenyl and sodium benzoate from benzene and sodium carbonate. The reaction happens in the interface of benzene and aqueous solution at the room temperature. After 5 h of UV-light exposure, 11.4% of initial amount of 4.4 g （5.0 mL） benzene are converted to biphenyl and sodium benzoate, which are distributed in benzene and aqueous solution, respectively. Using density function theory （DFT） and time dependent DFT, we have investigated the mechanism of this light-induced reaction, and found that the sodium carbonate is not only a reactant for the formation of sodium benzoate, but also a catalyst for the formation of biphenyl.展开更多
To realize automatic manipulation of micro-particles by light-induced dielectrophoresis （LDEP）, a path-planning scheme based on the improved artificial potential field （APF） for micro light pattern movements is pr...To realize automatic manipulation of micro-particles by light-induced dielectrophoresis （LDEP）, a path-planning scheme based on the improved artificial potential field （APF） for micro light pattern movements is proposed. An algorithm combining guided target and point obstacle based on a new local minimum judging criterion is specially designed, which can solve the local minimum problems encountered by the traditional APF. Experiments of real-time particle manipulation based on this algorithm are implemented and the experimental results show that the proposed approach can overcome the local minimum problems of the traditional APF method, and it is validated to be highly stable for intensive particle obstacles during LDEP manipulation. Consequently, this method can realize real-time manipulation of micro-nano particles with safety, decrease the difficulty of manual manipulation, and thus improve the efficiency of manipulation of micro-particles.展开更多
This paper presents dark oscillations of light-indhced absorption in heavy reduced Co: KNSBN crystal, points out there are double carriers and multiple traps in the crystal and explains the experimental results with t...This paper presents dark oscillations of light-indhced absorption in heavy reduced Co: KNSBN crystal, points out there are double carriers and multiple traps in the crystal and explains the experimental results with the newly established model of double carriers and multiple traps.展开更多
A visible-light induced metal-free approach was described for the hydroxyalkylation of 2 Hbenzothiazoles with alcohols by using selectfluor as the oxidant.A variety of 2 H-benzothiazoles and alcohols could be tolerate...A visible-light induced metal-free approach was described for the hydroxyalkylation of 2 Hbenzothiazoles with alcohols by using selectfluor as the oxidant.A variety of 2 H-benzothiazoles and alcohols could be tolerated,providing a mild and simple method for the synthesis of C2-hydroxyalkylated2 H-benzothiazoles in moderate to good yields.Besides,ethers were also compatible in this reaction,leading to corresponding C2 ether-substituted 2 H-benzothiazoles with high regioselectivity.展开更多
The phenomena of acoustic emission in LiNbO3：Fe：Ce crystals have been observed in the process of light-induced quasi-breakdown. It is found that the ultra-high frequency acoustic signal introduced into the crystal i...The phenomena of acoustic emission in LiNbO3：Fe：Ce crystals have been observed in the process of light-induced quasi-breakdown. It is found that the ultra-high frequency acoustic signal introduced into the crystal is modulated by the low frequency acoustic waves. Its frequency increases with the increase of the intensity of incident light and its jump period of breakdown is the same as that of the photovoltaic current Ic, the change of light-induced refractive index △n and the diffracted light intensity L. This phenomenon has been analysed in this paper, which is caused by the inverse piezoelectric strain effect of the jump of space charge field during the quasi-breakdown.展开更多
The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ...The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.展开更多
The present paper covers the lipid-free rhodium tetrasulfonato-phthalocyanine (RhTSPc) films prepared on p-Si(111) by using Langmuir-Blodgett technique. Their surface photovoltage spectra were measured. It was found t...The present paper covers the lipid-free rhodium tetrasulfonato-phthalocyanine (RhTSPc) films prepared on p-Si(111) by using Langmuir-Blodgett technique. Their surface photovoltage spectra were measured. It was found that there is a strong interaction at the interface between the RhTSPc film and p-Si (111) and that the surface photovoltaic effect of the film system is maximum when only one monolayer of RhTSPc molecules coats p-Si(111), which is similar to that of CuTSPc films on p-Si(111) reported previously. These results confirm that only the monolayer of dye molecules being adjacent to the semiconductor surface plays a key role in the light-induced interfacial charge transfer process.展开更多
AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in r...AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in retinal pericytes on photoreceptor loss and Müller glial response.METHODS:Sprague-Dawley rats were exposed to intense light to induce retinal injury.Neutralizing antibody against PDGFRβwere deployed to block the signaling pathway in retinal pericytes through intravitreal injection.Retinal histology and Müller glial reaction were assessed following light injury.In vitro,normal and PDGFRβ-blocked retinal pericytes were cocultured with Müller cell line(rMC-1)to examine morphological and protein expression changes upon supplementation with light-injured supernatants of homogenized retinas(SHRs).RESULTS:PDGFRβblockage 24h prior to intense light exposure resulted in a significant exacerbation of photoreceptor loss.The upregulation of GFAP and p-STAT3,observed after intense light exposure,was significantly inhibited in the PDGFRβblockage group.Fur ther upregulation of cytokines monocyte chemoattractant protein 1(MCP-1)and interleukin-1β(IL-1β)was also observed following PDGFRβinhibition.In the in vitro coculture system,the addition of light-injured SHRs induced pericyte deformation and upregulation of proliferating cell nuclear antigen(PCNA)expression,while Müller cells exhibited neuron-like morphology and expressed Nestin.However,PDGFRβblockage in retinal pericytes abolished these cellular responses to light-induced damage,consistent with the in vivo PDGFRβblockage findings.CONCLUSION:Pericyte-Müller glia interaction plays a potential role in the endogenous repair process of retinal injury.Impairment of this interaction exacerbates photoreceptor degeneration in light-induced retinal injury.展开更多
Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Met...Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Methods: Experiment No. 1. Early demineralized lesions in the upper and lower incisors and canines were visually inspected by three dentists and by QLF-D. The numbers of tooth planes with early demineralized lesions were compared between the methods. Experiment No. 2. Approximal demineralized lesions in molars were assessed by visual inspection, x-ray imaging, and QLF-D. The numbers of tooth planes with demineralized lesions were compared among the methods. Experiment No. 3. Plaque distribution was evaluated by QLF-D and a traditional staining method. The ratio of the diameter of plaque to tooth crown in the tooth axis direction in each method was calculated. The results were evaluated by Pearson’s correlation coefficient analysis and Bland-Altman plot. Results: Experiment No. 1. The three dentists found 0.67 tooth planes on average. QLF-D found 22 tooth planes with early demineralized lesions in the same samples. Experiment No. 2. Fourteen approximal tooth planes of molars were found to have demineralized lesions by x-ray imaging. QLF-D detected 71.4% of the tooth planes out of the 14, whereas visual inspection found 7.1%. Experiment No. 3. The Pearson’s correlation coefficient for the evaluations of plaque distribution between the QLF-D and traditional staining methods was 0.77 (P Conclusion: The results support introduction of QLF-D for use in school dental examinations.展开更多
As erosion has become one of the serious oral health problems, some fluoride-releasing dental materials have been developed to protect enamel from demineralization. The purpose of this study was to evaluate the antide...As erosion has become one of the serious oral health problems, some fluoride-releasing dental materials have been developed to protect enamel from demineralization. The purpose of this study was to evaluate the antidemineralization effect of PRG Barrier Coat<sup>®</sup> and FujiVII<sup>®</sup> (fluoride-releasing dental materials). Four square windows measuring 1 mm<sup>2</sup> were prepared on the labial enamel surface of each bovine tooth using masking tape and nail varnish. The first and second windows were half covered by fluoride-releasing material and control material, respectively, whereas the third and fourth windows were left untreated. All windows were immersed into 0.1 M lactic acid and 6wt% CM-cellulose (pH 4.5) at 38℃ for 21 days. Subsequently, the first and second windows were covered with nail varnish after removal of the materials, and the third and fourth windows were immersed into ultrapure water at 38℃ for 28 days after being half covered with fluoride-releasing and control materials, respectively. The following procedure was performed separately during evaluations of the fluoride-releasing materials, PRG Barrier Coat, and FujiVII<sup>®</sup>, using eight and six bovine teeth, respectively. The first, second, third, and fourth windows were classified into DM-PRG;Demineralized-PRG or DM-FujiVII;Demineralized-FujiVII, DM-TCM;Demineralized-traditional cement or DM-TGIC;De-mineralized-traditional glass ionomer cement, RM-PRG;Remineralized-PRG or RM-FujiVII;Re-mineralized-FujiVII, and RM-TCM;Remineralized- traditional cement or RM-TGIC;Remineral-ized-traditional glass ionomer cement, respectively. After nail varnish was removed, △Q values (mean ± SD) of the windows were measured using QLF-D and were compared between DM-PRG and DM-TCM, RM-PRG and RM-TCM, DM-FujiVII and DM-TGIC, and RM-FujiVII and RM-TGIC groups. △Q values of RM-PRG (-60 ± 44) and RM-FujiVII (-5.0 ± 10) were significantly higher than that of RM-TCM (-315 ± 193) and RM-TGIC (-56 ± 43), respectively. The fluoride releasing materials provided remineralization effects to bovine enamel.展开更多
基金supported financially by the National Key R&D Program of China(Grant No.2023YFE0111500)the National Natural Science Foundation of China(Grant Nos.52321006,T2394480,T2394484,22109143,22475196,22479131)+11 种基金the Research Grants Council of Hong Kong(CRF C4005-22YRGC Senior Research Fellowship Scheme(SRFS2223-5S01))the Joint Fund for Provincial Science and Technology R&D Program of Henan(grant no.242301420051)the Opening Project of the State Key Laboratory of Advanced Technology for Float Glass(grant no.2022KF04)the China Postdoctoral Innovative Talent Support Program(grant no.BX2021271)the China Postdoctoral Science Foundation(grant no.2022M712851)the Graduate Education Reform Project of Henan Province(Grant No.2023SJGLX136Y)the Key R&D Special Program of Henan Province(Grant No.241111242000)the Program for Science&Technology Innovation Talents in Universities of Henan Province(Grant No.25HASTIT005)the Training Plan for Young Backbone Teachers of Zhengzhou University(Grant No.2023ZDGGJS017)the Joint Research Project of Puyang ShengtongJuyuan New Materials Co.Ltd.(Grant No.20230128A)。
文摘Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibility to light-induced phase segregation(LIPS)limits efficiency and stability.In this work,we investigate the effect of three organic additives-4-cyclopentene-1,3-dione(CPD),maleimide(HPD),and 3,4-dibromo-1H-pyrrole-2,5(2H,5H)-dione(BrPD)-on LIPS in wide-bandgap CsPbIBr_(2)perovskite films.The additives form various chemical interactions,including coordination bonds,hydrogen bonds,and ionic bonds,with I^(-)and undercoordinated Pb^(2+)ions,among which BrPD has the strongest interaction.This interaction regulates crystallization and improves film morphology.The BrPD-modified films have the largest grain size and the highest light stability,suppressing LIPS,enhancing carrier transfer,and improving device performance.BrPD-modified CsPbIBr_(2)-based solar cells achieve a power conversion efficiency(PCE)of 11.34%,outperforming the control(8.96%)and other additives.Moreover,BrPDmodified devices show excellent stability,retaining 94%of their initial PCE after 60 min of continuous light exposure.This work highlights the potential of strategically selected organic additives to enhance the stability and performance of perovskite solar cells,offering valuable insights for the design of high-efficiency and long-lasting perovskite-based optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.12134005 and 12334011)the Major Research Plan of the National Natural Science Foundation of China(Grant No.92461301)。
文摘Light-induced conical intersections(LICIs)present a distinctive mechanism for nonadiabatic coupling,thereby facilitating ultrafast chemical reactions,including the indirect photodissociation of diatomic molecules.In contrast to static conical intersections,LICIs are dynamically tunable,providing a pathway for precise control of molecular dissociation.In this study,we employ the time-dependent quantum wave packet method to investigate the dissociation dynamics of the OH molecule,focusing on its ground state X^(2)Πand repulsive state 1^(2)Σ~-.By varying laser field parameters(intensity,full width at half maximum(FWHM),and wavelength),we elucidate how nonadiabatic coupling governs selective dissociation channel control.Our findings reveal that the choice of initial vibrational states and the tailoring of laser conditions significantly influence dissociation pathways,providing theoretical insights into manipulating molecular dynamics via LICIs.These results provide a foundation for future experimental studies and the development of advanced molecular control techniques.
基金Project supported by the National Natural Science Foundation of China(Grant No.10874249)
文摘The evolution of two-component cold atoms on a ring with spin-orbit coupling has been studied analytically for the case with N noninteracting particles. Then, the effect of interaction is evaluated numerically via a two-body system. Two cases are considered： （i） Starting from a ground state the evolution is induced by a sudden change of the laser field, and （ii） the evolution starting from a superposition state. Oscillating persistent spin-currents have been found. A set of formulae have been derived to describe the period and amplitude of the oscillation. Based on these formulae the oscillation can be well controlled via adjusting the parameters of the laser beams. In particular, it is predicted that movable stripes might emerge on the ring.
基金supported by the National Natural Science Foundation of China(Grant Nos.62335006,62275065,62022032,62405078,and 62505066)Open Subject of Hebei Key Laboratory of Advanced Laser Technology and Equipment(Grant No.HBKL-ALTE2025001)+2 种基金Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23144 and LBH-Z24155)Natural Science Foundation of Heilongjiang Province(Grant No.LH2024F031)China Postdoctoral Science Foundation(Grant No.2024M764172).
文摘In this paper,a novel self-designed inverted-triangular lithium niobate tuning fork(LiNTF)was used to construct gas sensing system for the first time.The optimal ratio of the upper and lower boundaries of the inverted-triangular LiNTF is found by scanning through finite element analysis(FEA).The surface charge density and stress value of the inverted-triangular LiNTF are both higher than those of the standard quartz tuning fork(QTF).In the lithium niobate-enhanced photoacoustic spectroscopy(LiNPAS)sensing system,the 2f peak and signal-to-noise ratio(SNR)of the inverted-triangular LiNTF are 7.41 times and 5.89 times those of the standard QTF,respectively.After forming acoustic standing wave field with the acoustic micro-resonator(AmR),the LiNPAS system achieves an SNR 56.16 times higher than without the AmR.Based on Allan variance analysis,the system achieves a minimum detection limit(MDL)of 7.25 ppb with an averaging time of 800 seconds.In the light-induced thermoelastic spectroscopy(LITES)sensing system,the 2f peak and SNR of the inverted-triangular LiNTF are 7.82 times and 6.03 times those of the standard QTF,respectively.When the averaging time reaches 100 s,the MDL of the system is found to be 25.78 ppb.
基金National Key Research and Development Program of China(2021YFB3700801)。
文摘Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into the new β phase during the pulsed current-assisted aging process,and then the newly formed β phase is mainly transformed into the β_(t) phase,with occasional transition to new α_(p) phase,leading to a remarkable grain refinement,especially for the lamellarαs phases.In comparison to conventional aging treatment,the pulsed current-assisted aging approach achieves a significant enhancement in strength without degrading ductility,yielding an excellent mechanical property combination:a yield strength of 932 MPa,a tensile strength of 1042 MPa,and an elongation of 12.2%.It is primarily ascribed to the increased fraction of β_(t) phases,the obvious grain refinement effect,and the slip block effect induced by the multiple-variantαs colonies distributed within β_(t) phases.
基金Supported by the Fundamental Research Funds for the Central Universities(2024ZYGXZR047)the National Natural Science Foundation of China(62373156)the Guangdong Basic and Applied Basic Research Foundation(2024A1515011736)。
文摘This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters.
基金supported by Natural Science Foundation of Wuhan(2024040701010051)Natural Science Foundation of Hubei(2023AFB111)and National Natural Science Foundation of China(52401108).
文摘To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.
文摘Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.
基金funded by Youth Talent Growth Project of Guizhou Provincial Department of Education(No.Qianjiaoji[2024]21)National Natural Science Foundation of China(No.62461008 and No.52507211)Guizhou Provincial Key Technology R&D Program(No.[2024]General 049).
文摘To address the issues of high costs and low component utilization caused by the independent configuration of hybrid DC circuit breakers(HCBs)and DC power flow controllers(DCPFCs)at each port in existing DC distribution networks,this paper adopts a component sharing mechanism to propose a composite multi-port hybrid DC circuit breaker(CM-HCB)with DC power flow and fault current limitation abilities,as well as reduced component costs.The proposed CM-HCB topology enables the sharing of the main breaker branch(MB)and the energy dissipation branch,while the load commutation switches(LCSs)in the main branch are reused as power flow control components,enabling flexible regulation of power flow in multiple lines.Meanwhile,by reconstructing the current path during the fault process,the proposed CM-HCB can utilize the internal coupled inductor to limit the current rise rate at the initial stage of the fault,significantly reducing the requirement for breaking current.A detailed study on the topological structure,steady-state power flow regulation mechanism,transient fault isolation mechanism,control strategy and characteristic analysis of the proposed CM-HCB is presented.Then,a Matlab/Simulink-based meshed three-terminal DC grid simulation platform with the proposed CM-HCB is built.The results indicate that the proposed CM-HCB can not only achieve flexible power flow control during steady-state operation,but also obtain current rise limitation and fault isolation abilities under short-circuit fault conditions,verifying its correctness and effectiveness.Finally,a comparative economic analysis is conducted between the proposed CM-HCB and the other two existing solutions,confirming that its component sharing mechanism can significantly reduce the number of components,lower system costs,and improve component utilization.
文摘Light induced changes in a-Si∶H films are investigated by transient photoconductivity.The transient photoconductivity decay data can neither be fit well by common power-law for transient photocurrent in amorphous semiconductors,nor by stretched exponential rule for transient decay from the steady state in photoconductivity.Instead,the data are fit fairly well with a sum of two exponential functions.The results show that the long time decay is governed by deep traps rather than band tail states,and two different traps locating separately at 0.52 and 0.59eV below E _c are responsible for the two exponential functions.They are designated as negatively charged dangling bond D - centers.The light-induced changes in photoconductivity are attributed mainly to the decrease in electron lifetime caused by the increase of recombination centers after light soaking.
文摘We found an ultraviolet （UV）-light induced formation of biphenyl and sodium benzoate from benzene and sodium carbonate. The reaction happens in the interface of benzene and aqueous solution at the room temperature. After 5 h of UV-light exposure, 11.4% of initial amount of 4.4 g （5.0 mL） benzene are converted to biphenyl and sodium benzoate, which are distributed in benzene and aqueous solution, respectively. Using density function theory （DFT） and time dependent DFT, we have investigated the mechanism of this light-induced reaction, and found that the sodium carbonate is not only a reactant for the formation of sodium benzoate, but also a catalyst for the formation of biphenyl.
基金The National Natural Science Foundation of China(No.91023024,51175083)Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1020)Jiangsu Graduate Innovative Research Program(No.CX10B_062Z).
文摘To realize automatic manipulation of micro-particles by light-induced dielectrophoresis （LDEP）, a path-planning scheme based on the improved artificial potential field （APF） for micro light pattern movements is proposed. An algorithm combining guided target and point obstacle based on a new local minimum judging criterion is specially designed, which can solve the local minimum problems encountered by the traditional APF. Experiments of real-time particle manipulation based on this algorithm are implemented and the experimental results show that the proposed approach can overcome the local minimum problems of the traditional APF method, and it is validated to be highly stable for intensive particle obstacles during LDEP manipulation. Consequently, this method can realize real-time manipulation of micro-nano particles with safety, decrease the difficulty of manual manipulation, and thus improve the efficiency of manipulation of micro-particles.
文摘This paper presents dark oscillations of light-indhced absorption in heavy reduced Co: KNSBN crystal, points out there are double carriers and multiple traps in the crystal and explains the experimental results with the newly established model of double carriers and multiple traps.
基金the financial support by the National Natural Science Foundation of China(No.30900959)the Natural Science Foundation of Zhejiang Province(No.LY17C140003)。
文摘A visible-light induced metal-free approach was described for the hydroxyalkylation of 2 Hbenzothiazoles with alcohols by using selectfluor as the oxidant.A variety of 2 H-benzothiazoles and alcohols could be tolerated,providing a mild and simple method for the synthesis of C2-hydroxyalkylated2 H-benzothiazoles in moderate to good yields.Besides,ethers were also compatible in this reaction,leading to corresponding C2 ether-substituted 2 H-benzothiazoles with high regioselectivity.
基金Project supported by the National Natural Science Foundation of China （Grant No 69908003）.
文摘The phenomena of acoustic emission in LiNbO3：Fe：Ce crystals have been observed in the process of light-induced quasi-breakdown. It is found that the ultra-high frequency acoustic signal introduced into the crystal is modulated by the low frequency acoustic waves. Its frequency increases with the increase of the intensity of incident light and its jump period of breakdown is the same as that of the photovoltaic current Ic, the change of light-induced refractive index △n and the diffracted light intensity L. This phenomenon has been analysed in this paper, which is caused by the inverse piezoelectric strain effect of the jump of space charge field during the quasi-breakdown.
基金supported in part by Natural Science Foundation of Jiangsu Province under Grant BK20230255Natural Science Foundation of Shandong Province under Grant ZR2023QE281.
文摘The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.
基金Supported by the National Natural Science Foundation of China
文摘The present paper covers the lipid-free rhodium tetrasulfonato-phthalocyanine (RhTSPc) films prepared on p-Si(111) by using Langmuir-Blodgett technique. Their surface photovoltage spectra were measured. It was found that there is a strong interaction at the interface between the RhTSPc film and p-Si (111) and that the surface photovoltaic effect of the film system is maximum when only one monolayer of RhTSPc molecules coats p-Si(111), which is similar to that of CuTSPc films on p-Si(111) reported previously. These results confirm that only the monolayer of dye molecules being adjacent to the semiconductor surface plays a key role in the light-induced interfacial charge transfer process.
基金Supported by National Natural Science Foundation of China(No.81900862)。
文摘AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in retinal pericytes on photoreceptor loss and Müller glial response.METHODS:Sprague-Dawley rats were exposed to intense light to induce retinal injury.Neutralizing antibody against PDGFRβwere deployed to block the signaling pathway in retinal pericytes through intravitreal injection.Retinal histology and Müller glial reaction were assessed following light injury.In vitro,normal and PDGFRβ-blocked retinal pericytes were cocultured with Müller cell line(rMC-1)to examine morphological and protein expression changes upon supplementation with light-injured supernatants of homogenized retinas(SHRs).RESULTS:PDGFRβblockage 24h prior to intense light exposure resulted in a significant exacerbation of photoreceptor loss.The upregulation of GFAP and p-STAT3,observed after intense light exposure,was significantly inhibited in the PDGFRβblockage group.Fur ther upregulation of cytokines monocyte chemoattractant protein 1(MCP-1)and interleukin-1β(IL-1β)was also observed following PDGFRβinhibition.In the in vitro coculture system,the addition of light-injured SHRs induced pericyte deformation and upregulation of proliferating cell nuclear antigen(PCNA)expression,while Müller cells exhibited neuron-like morphology and expressed Nestin.However,PDGFRβblockage in retinal pericytes abolished these cellular responses to light-induced damage,consistent with the in vivo PDGFRβblockage findings.CONCLUSION:Pericyte-Müller glia interaction plays a potential role in the endogenous repair process of retinal injury.Impairment of this interaction exacerbates photoreceptor degeneration in light-induced retinal injury.
文摘Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Methods: Experiment No. 1. Early demineralized lesions in the upper and lower incisors and canines were visually inspected by three dentists and by QLF-D. The numbers of tooth planes with early demineralized lesions were compared between the methods. Experiment No. 2. Approximal demineralized lesions in molars were assessed by visual inspection, x-ray imaging, and QLF-D. The numbers of tooth planes with demineralized lesions were compared among the methods. Experiment No. 3. Plaque distribution was evaluated by QLF-D and a traditional staining method. The ratio of the diameter of plaque to tooth crown in the tooth axis direction in each method was calculated. The results were evaluated by Pearson’s correlation coefficient analysis and Bland-Altman plot. Results: Experiment No. 1. The three dentists found 0.67 tooth planes on average. QLF-D found 22 tooth planes with early demineralized lesions in the same samples. Experiment No. 2. Fourteen approximal tooth planes of molars were found to have demineralized lesions by x-ray imaging. QLF-D detected 71.4% of the tooth planes out of the 14, whereas visual inspection found 7.1%. Experiment No. 3. The Pearson’s correlation coefficient for the evaluations of plaque distribution between the QLF-D and traditional staining methods was 0.77 (P Conclusion: The results support introduction of QLF-D for use in school dental examinations.
文摘As erosion has become one of the serious oral health problems, some fluoride-releasing dental materials have been developed to protect enamel from demineralization. The purpose of this study was to evaluate the antidemineralization effect of PRG Barrier Coat<sup>®</sup> and FujiVII<sup>®</sup> (fluoride-releasing dental materials). Four square windows measuring 1 mm<sup>2</sup> were prepared on the labial enamel surface of each bovine tooth using masking tape and nail varnish. The first and second windows were half covered by fluoride-releasing material and control material, respectively, whereas the third and fourth windows were left untreated. All windows were immersed into 0.1 M lactic acid and 6wt% CM-cellulose (pH 4.5) at 38℃ for 21 days. Subsequently, the first and second windows were covered with nail varnish after removal of the materials, and the third and fourth windows were immersed into ultrapure water at 38℃ for 28 days after being half covered with fluoride-releasing and control materials, respectively. The following procedure was performed separately during evaluations of the fluoride-releasing materials, PRG Barrier Coat, and FujiVII<sup>®</sup>, using eight and six bovine teeth, respectively. The first, second, third, and fourth windows were classified into DM-PRG;Demineralized-PRG or DM-FujiVII;Demineralized-FujiVII, DM-TCM;Demineralized-traditional cement or DM-TGIC;De-mineralized-traditional glass ionomer cement, RM-PRG;Remineralized-PRG or RM-FujiVII;Re-mineralized-FujiVII, and RM-TCM;Remineralized- traditional cement or RM-TGIC;Remineral-ized-traditional glass ionomer cement, respectively. After nail varnish was removed, △Q values (mean ± SD) of the windows were measured using QLF-D and were compared between DM-PRG and DM-TCM, RM-PRG and RM-TCM, DM-FujiVII and DM-TGIC, and RM-FujiVII and RM-TGIC groups. △Q values of RM-PRG (-60 ± 44) and RM-FujiVII (-5.0 ± 10) were significantly higher than that of RM-TCM (-315 ± 193) and RM-TGIC (-56 ± 43), respectively. The fluoride releasing materials provided remineralization effects to bovine enamel.
