Two-dimensional(2D)MoS_(2) is considered an excellent candidate material for nextgeneration photodetectors.However,the high dark current and low photocurrent in MoS_(2) devices severely hinder their practical applicat...Two-dimensional(2D)MoS_(2) is considered an excellent candidate material for nextgeneration photodetectors.However,the high dark current and low photocurrent in MoS_(2) devices severely hinder their practical application.Strategies for suppressing dark current and enhancing photocurrent should be explored.Herein,we propose a modification strategy for MoS_(2) by utilizing Ag_(70) nanoclusters(NCs)as electron reservoirs and photoabsorbers to suppress dark current and enhance the photocurrent of 2D MoS_(2) photodetector.Remarkably,the dark current is effectively suppressed by four orders of magnitude,while the photocurrent is enhanced by over tenfold upon modification with Ag_(70) NCs,compared to the pristine MoS_(2) photodetector.The reduction in dark current is attributed to charge transfer from MoS_(2) to Ag_(70) NCs owing to the strong electronwithdrawing property of Ag_(70) NCs.The increase in photocurrent benefits from enhanced optical absorption of the photodetector after Ag_(70) NCs modification and the subsequent injection of photoexcited electrons from Ag_(70) NCs to MoS_(2).Compared to isolated MoS_(2),the modulated photodetector shows exceptional improvements in several key figures of merit(such as responsivity,detectivity,external quantum efficiency,and photoswitching on/off ratio).This study opens up new avenues for building high-performance 2D MoS_(2) photodetectors.展开更多
A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep aval...A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep avalanche multiplication region for near-infrared(NIR)sensitivity enhancement.By optimizing the device size and electric field of the guard ring,the fill factor(FF)is significantly improved,further increasing photon detection efficiency(PDE).To solve the dark noise caused by the increasing active diameter,a field polysilicon gate structure connected to the p+anode was investigated,effectively suppressing dark count noise by 76.6%.It is experimentally shown that when the active diameter increases from 5 to 10μm,the FF is significantly improved from 20.7%to 39.1%,and thus the peak PDE also rises from 13.3%to 25.8%.At an excess bias voltage of 5 V,a NIR photon detection probability(PDP)of 6.8%at 905 nm,a dark count rate(DCR)of 2.12 cps/μm^(2),an afterpulsing probability(AP)of 1.2%,and a timing jitter of 216 ps are achieved,demonstrating excellent single photon detection performance.展开更多
Complex Field Theory (CFT) proposes that dark matter (DM) and dark energy (DE) are pervasive, complex fields of charged complex masses of equally positive and negative complex charges, respectively. It proposes that e...Complex Field Theory (CFT) proposes that dark matter (DM) and dark energy (DE) are pervasive, complex fields of charged complex masses of equally positive and negative complex charges, respectively. It proposes that each material object, including living creatures, is concomitant with a fraction of the charged complex masses of DM and DE in proportion to its mass. This perception provides new insights into the physics of nature and its constituents from subatomic to cosmic scales. This complex nature of DM and DE explains our inability to see DM or harvest DE for the last several decades. The positive complex DM is responsible for preserving the integrity of galaxies and all material systems. The negative complex charged DE induces a positive repelling force with the positively charged DM and contributes to the universe’s expansion. Both fields are Lorentz invariants in all directions and entangle the whole universe. The paper uses CFT to investigate zero-point energy, particle-wave duality, relativistic mass increase, and entanglement phenomenon and unifies Coulomb’s and Newton’s laws. The paper also verifies the existence of tachyons and explains the spooky action of quantum mechanics at a distance. The paper encourages further research into how CFT might resolve several physical mysteries in physics.展开更多
This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediat...This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediators of dark forces.The ECAL design was evaluated through comprehensive simulations,focusing on optimizing dimensions,material selection,energy distribution,and energy resolution.The configuration consisted of 21×21×11 LYSO crystals,each measuring 2.5 cm×2.5 cm×4 cm,arranged in a staggered layout to enhance signal detection efficiency.A 4 GeV energy dynamic range was established to ensure accurate energy measurements without saturation,which is essential for background rejection and signal identification.A detailed digitization model was developed to simulate scintillation,silicon photomultiplier,and analog-to-digital converter behaviors,providing a realistic representation of the detector's performance.Additionally,the study assessed radiation damage in the ECAL region,emphasizing the importance of using radiation-resistant scintillators and silicon sensors.展开更多
While cold dark matter is widely supported by a range of cosmological observations,it encounters several difficulties at smaller scales.These issues have prompted the investigation of various alternative dark matter c...While cold dark matter is widely supported by a range of cosmological observations,it encounters several difficulties at smaller scales.These issues have prompted the investigation of various alternative dark matter candidates,leaving the question“What is dark matter?”still open.In this work,we propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant.We then place constraints on our new model using the Planck 2018 Cosmic Microwave Background(CMB)anisotropy measurements,Baryon Acoustic Oscillation measurements from the Dark Energy Spectroscopic Instrument(DESI),the Pantheon Plus(PP)compilation of Type Ia supernovae,and the Redshift Space Distortions(RSD)data from Gold 2018.The results show statistically significant signal for positive dark matter equation of state and square of sound speed w_(dm)=c_(s,dm)^(2)(10^(7) w_(dm)=4.0_(-2.3)^(+2.5)at the 95%confidence level)for the data combination CMB+DESI+PP+RSD.However,Bayesian evidence indicates that this data combination favors theΛCDM model with very strong evidence.展开更多
Detailed and redundant measurements of dark matter properties have recently become available. To describe the observations we consider scalar, vector and sterile neutrino dark matter models. A model with vector dark m...Detailed and redundant measurements of dark matter properties have recently become available. To describe the observations we consider scalar, vector and sterile neutrino dark matter models. A model with vector dark matter is consistent with all current observations.展开更多
The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, deg...The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, degenerate, spinless boson. Contour integration produces dark matter equations of state.展开更多
The subject is the thermodynamics of dark energy. Thermodynamically, the ratio of dark energy to CMR temperature has the units of entropy, has a well-defined numerical value at every moment of cosmological history, an...The subject is the thermodynamics of dark energy. Thermodynamically, the ratio of dark energy to CMR temperature has the units of entropy, has a well-defined numerical value at every moment of cosmological history, and increases in time monotonically without limit. The proposal is that it is the cosmological entropy, aka dark entropy. Discussion compares it to other notions of entropy. Dark entropy is a necessary prelude to DEH IV, which is about the thermodynamics of dark matter.展开更多
Health monitoring of underwater concrete facility systems is important in civil engineering. Unlike conventional manual inspection techniques, digital image processing offers a more convenient and effective approach, ...Health monitoring of underwater concrete facility systems is important in civil engineering. Unlike conventional manual inspection techniques, digital image processing offers a more convenient and effective approach, becoming an indispensable tool for structural inspection. Cracks, which are pervasive defects, are a central focus of structural deterioration research. However, the complexity of the marine environment poses challenges to underwater visibility.In this study, the underwater environment under controlled laboratory conditions is replicated, where varying turbidity and illumination conditions and images of concrete cracks are captured. An approach combining a defogging algorithm with guided and fast guided filtering techniques is proposed to enhance both natural underwater images and crack images captured through experimental photography. When applied to turbid crack images captured under two different suspension conditions, the method increases the information entropy(IE) by 32.92% and 17.92% and the underwater color image quality evaluation(UCIQE) by 35.76% and 18.36%, respectively. These results demonstrate its efficiency in enhancing image definition. The findings of this study could significantly impact the practical applications of image visualization and evaluation for underwater concrete cracks.展开更多
AIM:To compare the efficacy of different administration regimens of compound tropicamide eyedrops(CTE)for pupil dilation for children with dark iris.METHODS:A prospective,comparative,randomized interventional study wa...AIM:To compare the efficacy of different administration regimens of compound tropicamide eyedrops(CTE)for pupil dilation for children with dark iris.METHODS:A prospective,comparative,randomized interventional study was conducted.Children in Group 1 received CTE 3 times with a 3min interval between each application.Children in Group 2 received CTE 4 times with a 5min interval between each application.We measured their pupil diameters at baseline(pre-drug instillation)and 30min and 60min post-drug instillation and assessed the pupillary light reflex at 60min post-drug instillation.RESULTS:In total,194 eyes of 101 children were enrolled.The changes of pupil diameter at 30min and 60min post-drug instillation were 1.2±0.6 mm and 2.3±1.0 mm in Group 1,and 2.3±0.9 mm and 3.7±1.0 mm in Group 2,respectively.Group 2 showed a larger change in pupil size than Group 1 at 30min(P<0.01)and 60min(P<0.01).The effect of pupil dilation in Group 2 was 1.25 times that in Group 1.The change in pupil size was positively associated with age.A higher proportion of children in Group 1 had smaller pupil diameter and reactive pupils at the final time point,with only 33 children(33.7%)had final pupil size≥6.5 mm,and only 9 children(9.2%)had non-reactive pupils.Children in Group 2 achieved larger pupil diameter and more nonreactive pupils at the final time point,with 84 children(87.5%)had final pupil size≥6.5 mm,and only 22 children(22.9%)had reactive pupils.CONCLUSION:Increasing the frequency of compound tropicamide and lengthening the interval between eye drop applications can produce stronger mydriatic effects.展开更多
While bagged flat peaches gain increasing consumer preference,the bagging process inhibits anthocyanin production and fruit coloration in most peach cultivars.Certain peach cultivars,including the rapidly expanding‘Z...While bagged flat peaches gain increasing consumer preference,the bagging process inhibits anthocyanin production and fruit coloration in most peach cultivars.Certain peach cultivars,including the rapidly expanding‘Zhongyoupan 9’,demonstrate a light-independent anthocyanin biosynthesis pattern and accumulate anthocyanins under artificial darkness.The underlying molecular mechanisms,however,remain unelucidated.This study examined two flat peach varieties:‘Zhongpan 17’,exhibiting light-dependent anthocyanin biosynthesis,and‘Zhongyoupan 9’,displaying light-independent anthocyanin biosynthesis.The pericarp of‘Zhongyoupan 9’contained substantially higher anthocyanin levels compared to‘Zhongpan 17’.Metabolomic analysis identified the marked increase in anthocyanins,particularly cyanidin-3-O-glucoside,as the primary factor in‘Zhongyoupan 9’coloration under artificial darkness.Transcriptomic analyses revealed that PpHY5(long hypocotyl 5)showed upregulation in‘Zhongyoupan 9’but downregulation in‘Zhongpan 17’,with its expression pattern correlating positively with color changes in both varieties.The role of PpHY5 in positively regulating anthocyanin biosynthesis was confirmed through reduced anthocyanin levels in peach fruits treated with a PpHY5 virus-induced gene-silencing construct.These findings suggest that the PpHY5 regulates red color development in‘Zhongyoupan 9’under artificial darkness.展开更多
In this paper we consider a static spherically symmetric black hole(BH)embedded in a Dehnen-(1,4,0)-type dark matter(DM)halo in the presence of a cloud string.We examine and present data on how the core density of the...In this paper we consider a static spherically symmetric black hole(BH)embedded in a Dehnen-(1,4,0)-type dark matter(DM)halo in the presence of a cloud string.We examine and present data on how the core density of the DM halo parameter and the cloud string parameter affect BH attributes such as quasinormal modes(QNMs)and shadow cast.To do this,we first look into the effective potential of perturbation equations for three types of perturbation fields with different spins:massless scalar field,electromagnetic field and gravitational field.Then,using the sixth-order Wentzel-Kramers-Brillouin approximation,we examine QNMs of the BH disturbed by the three fields and derive quasinormal frequencies.The changes in QNM versus the core density parameter and the cloud string parameter for three disturbances are explored.We also investigate how the core density and the cloud string parameter affect the photon sphere and shadow radius.Interestingly,the study shows that the influence of Dehnen-type DM and cloud strings increases both the photon sphere and the shadow radius.Finally,we employ observational data from Sgr A^(*) and M87^(*) to set limitations on the BH parameters.展开更多
Research on the properties of neutron stars with dark energy is a particularly interesting yet unresolved problem in astrophysics.We analyze the influence of dark energy on the equation of state,the maximum mass,the s...Research on the properties of neutron stars with dark energy is a particularly interesting yet unresolved problem in astrophysics.We analyze the influence of dark energy on the equation of state,the maximum mass,the surface gravitational redshift and the Keplerian frequency for the traditional neutron star and the hyperon star matter within the relativistic mean field theory,using the GM1 and TM1 parameter sets by considering the two flavor symmetries of SU(6)and SU(3)combined with the observations of PSR J1614-2230,PSR J0348+0432,PSR J0030+0451,RX J0720.4-3125,and 1E 1207.4-5209.It is found that the existence of dark energy leads to the softened equations of the state of the traditional neutron star and the hyperon star.The radius of a fixed-mass traditional neutron star(or hyperon star)with dark energy becomes smaller,which leads to increased compactness.The existence of dark energy can also enhance the surface gravitational redshift and the Keplerian frequency of traditional neutron stars and hyperon stars.The growth of the Keplerian frequency may cause the spin rate to speed up,which may provide a possible way to understand and explain the pulsar glitch phenomenon.Specifically,we infer that the mass and the surface gravitational redshift of PSR J1748-2446ad without dark energy for the GM1(TM1)parameter set are 1.141 M_(☉)(1.309 M_(☉))and 0.095(0.105),respectively.The corresponding values for the GM1(TM1)parameter set are 0.901 M_(☉)(1.072M_(☉))and 0.079(0.091)if PSR J1748-2446ad contains dark energy withα=0.05.PSR J1748-2446ad may be a low-mass pulsar with a lower surface gravitational redshift under our selected models.展开更多
Low dark current photocathode guns are highly desired for high-brightness continuous-wave operations.Direct-current superconducting radio-frequency(DC-SRF)gun,a hybrid photocathode gun combining a DC gap and an SRF ca...Low dark current photocathode guns are highly desired for high-brightness continuous-wave operations.Direct-current superconducting radio-frequency(DC-SRF)gun,a hybrid photocathode gun combining a DC gap and an SRF cavity,effectively isolates the photocathode from the SRF cavity and offers significant advantages in terms of minimizing dark current levels.This paper presents an in-depth analysis of the dark current of a newly developed high-brightness DC-SRF photocathode gun(DC-SRF-Ⅱ gun).Particularly,a systematic experimental investigation of the dark current was conducted,and a comprehensive understanding of its formation was achieved through compliant simulations and measurements.Additionally,measures for attaining sub-nanoampere dark currents in the DC-SRF-Ⅱ gun are presented,including design considerations,cavity processing,assembly,and conditioning.The findings of this study establish a strong foundation for achieving high-performance operation of the DC-SRF-Ⅱ gun and provide a valuable reference for other photocathode guns.展开更多
Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the ex...Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the expression of multiple senescence-related genes and physiological phenotypes were monitored in WRKY10-and VQ MOTIF-CONTAINING PROTEIN8(VQ8)-overexpressing plants and the wrky10 and vq8 mutants.Our results showed that WRKY10 positively regulates abscisic acid(ABA)-and dark-induced senescence(DIS)by directly regulating the expression of multiple senescence-related genes.The VQ8 protein,a repressor of WRKY10,negatively regulates WRKY10-mediated DIS.The WRKY10-VQ8 module fine-tunes the progression of DIS.ABA,methyl jasmonate,and H_(2)O_(2) accelerate WRKY10-mediated DIS,whereas ammonium nitrate and dithiothreitol delay WRKY10-mediated DIS.Further analysis revealed that WRKY10 and VQ8 interact with ABA RESPONSIVE ELEMENT BINDING FACTOR1(ABF1)or ABF2.VQ8 represses the transcriptional activity of ABF1 and ABF2.Overexpression of ABF1 or ABF2 accelerates ABA-and dark-induced senescence and H_(2)O_(2) accumulation in N.benthamiana leaves,and WRKY10 and VQ8 can inhibit either ABF1-or ABF2-induced cell necrosis.Taken together,WRKY10 integrates multiple senescence signals to establish an orderly progression of leaf senescence.The VQ8 protein acts as a brake on WRKY10-induced senescence and ABF1/2-induced cell death,preventing uncontrolled cell death.展开更多
Understanding the nature of dark matter remains one of the most enigmatic and unresolved issues in astrophysics.Certain theoretical models address this by introducing a novel component to account for dark matter.In th...Understanding the nature of dark matter remains one of the most enigmatic and unresolved issues in astrophysics.Certain theoretical models address this by introducing a novel component to account for dark matter.In this study,we propose a new scalar field derived from string T-duality,where its associated density represents the density of the surrounding matter field,in the spherically symmetric and static medium.Our exploration reveals that this scalar field behaves as the baryonic fluid,characterized by a positive effective state equation,ωe>0.Furthermore,a detailed investigation demonstrates that this model satisfies all energy conditions beyond the event horizon of a central black hole.Considering the light deflection and radar echo delay suggests that in this scalar field,the dark matter grows up in the halo and surrounding regions of galaxy systems.This indicates that dark matter accumulates as an effective field outside the observable regions of galaxies.展开更多
Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge ...Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge carrier mobility,and lightweight properties.However,these perovskite photodetectors exhibit relatively low absorption in the near-infrared(NIR)range,which limits their potential applications.Here,to address this challenge,the integration of gold nanorods(Au NRs)utilizing localized surface plasmon resonance(LSPR)effects in the NIR range has been developed,leading to enhanced light absorption in the active region and higher photocurrent generation.Additionally,∼7.9 nm of thin polyethyleneimine ethoxylated(PEIE)interlayers were incorporated into the Au NR photodetectors,suppressing dark current by blocking charge injection.As a result,the synergistic effect of the Au NR/PEIE hybrid layer has led to a high-performance photodetector with a responsivity of 0.360 A/W and a detectivity of 1.81×10^(10) Jones,demonstrating a noticeable enhancement compared to the control device.Finite-difference time-domain(FDTD)simulations,morphological characterizations,and photoluminescence studies further support the mechanism for enhancing the performance of the device.We believe that our plasmon-enhanced protocol holds strong potential as a promising platform for perovskite optoelectronic devices.展开更多
We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain...We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain the Jacobi's elliptic solution of the defocusing Hirota equation,and solve the related linear matrix eigenvalue problem on elliptic function background.The elliptic N-dark soliton solution in terms of theta functions is constructed by the Darboux transformation and limit technique.The asymptotic dynamical behaviors for the elliptic N-dark soliton solution as t→±∞are studied.Through numerical plots of the elliptic one-,two-and three-dark solitons,the amplification effect on the velocity of elliptic dark solitons,and the compression effect on the soliton spatiotemporal distributions produced by the third-order dispersion and self-steepening terms are discussed.展开更多
The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after i...The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after illumination.This limitation is bypassed in round-the-clock photocatalytic architectures,which incorporate advanced charge storage to de-correlate pho-ton absorption and catalytic turnover time scales.The strategies involve defect-mediated trap states,multi-electron redox processes,radical-dependent stabilization,and an interfacial charge pool in Faradaic junctions to work together,leading to extended hydrogen evolution reaction(HER)in the dark.Long afterglow phosphorescent materials(e.g.,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+))incorporated in heterojunction architectures with type II or Z-scheme band alignments can also promote fast charge separation for energy storage and subsequently enable controlled release after light quenching by the phosphorescent emis-sion.Advances in band-structure engineering,plasmonic coupling,and redox-active interfacial design result in systems with extraordinary stability and catalytic activity under natural day-night cycles.These stable photocatalytic systems off er a fundamentally new strategy for effi cient and environmentally benign sunlight-driven fuel production,meeting both per-formance and sustainability challenges to renewable energy technologies.展开更多
Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the ...Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the multiplication material exhibit excellent noise performance.In this work,we report a low-noise separate absorption,grading,charge,and multi-plication(SAGCM)InGaAs/AlGaAsSb APD operating at 1550 nm.A double-mesa structure was fabricated to reduce the dark cur-rent.Numerical simulations were conducted to compare two different mesa-structured APDs.By analyzing the electric field distri-bution,it was found that the electric field at the edge of the multiplication region in the double-mesa APD is nearly 100 kV/cm lower than that of the single-mesa structure.Experimental results demonstrate that after device punch-through,the double-mesa APD’s dark current can be reduced by up to four times compared to the single-mesa APD.Quantitative analysis of the dark current components in the AlGaAsSb APD further confirms that the low sidewall electric field in the double-mesa struc-ture effectively suppresses the trap-assisted tunneling.Additionally,noise measurements indicate a k-value of approximately 0.014,which is significantly lower than that of traditional multiplication materials.This work provides preliminary validation for further performance improvements in low noise and low dark current AlGaAsSb APDs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.92461304 and 52202192)China Postdoctoral Science Foundation(Nos.2020M682338 and 2023T160593)+2 种基金China National Postdoctoral Program for Innovative Talents(No.BX20230329)Zhengzhou Universitythe support from the Center of New Materials and Device of Huazhong University of Science and Technology.
文摘Two-dimensional(2D)MoS_(2) is considered an excellent candidate material for nextgeneration photodetectors.However,the high dark current and low photocurrent in MoS_(2) devices severely hinder their practical application.Strategies for suppressing dark current and enhancing photocurrent should be explored.Herein,we propose a modification strategy for MoS_(2) by utilizing Ag_(70) nanoclusters(NCs)as electron reservoirs and photoabsorbers to suppress dark current and enhance the photocurrent of 2D MoS_(2) photodetector.Remarkably,the dark current is effectively suppressed by four orders of magnitude,while the photocurrent is enhanced by over tenfold upon modification with Ag_(70) NCs,compared to the pristine MoS_(2) photodetector.The reduction in dark current is attributed to charge transfer from MoS_(2) to Ag_(70) NCs owing to the strong electronwithdrawing property of Ag_(70) NCs.The increase in photocurrent benefits from enhanced optical absorption of the photodetector after Ag_(70) NCs modification and the subsequent injection of photoexcited electrons from Ag_(70) NCs to MoS_(2).Compared to isolated MoS_(2),the modulated photodetector shows exceptional improvements in several key figures of merit(such as responsivity,detectivity,external quantum efficiency,and photoswitching on/off ratio).This study opens up new avenues for building high-performance 2D MoS_(2) photodetectors.
基金supported by the National Natural Science Foundation of China under Grant 62171233the Natural Science Foundation of China,Jiangsu Province under Grant BK20241891the Jiangsu Province Graduate Research and Practice Innovation Plan under Grants SJCX24_0313 and KYCX24_1169。
文摘A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep avalanche multiplication region for near-infrared(NIR)sensitivity enhancement.By optimizing the device size and electric field of the guard ring,the fill factor(FF)is significantly improved,further increasing photon detection efficiency(PDE).To solve the dark noise caused by the increasing active diameter,a field polysilicon gate structure connected to the p+anode was investigated,effectively suppressing dark count noise by 76.6%.It is experimentally shown that when the active diameter increases from 5 to 10μm,the FF is significantly improved from 20.7%to 39.1%,and thus the peak PDE also rises from 13.3%to 25.8%.At an excess bias voltage of 5 V,a NIR photon detection probability(PDP)of 6.8%at 905 nm,a dark count rate(DCR)of 2.12 cps/μm^(2),an afterpulsing probability(AP)of 1.2%,and a timing jitter of 216 ps are achieved,demonstrating excellent single photon detection performance.
文摘Complex Field Theory (CFT) proposes that dark matter (DM) and dark energy (DE) are pervasive, complex fields of charged complex masses of equally positive and negative complex charges, respectively. It proposes that each material object, including living creatures, is concomitant with a fraction of the charged complex masses of DM and DE in proportion to its mass. This perception provides new insights into the physics of nature and its constituents from subatomic to cosmic scales. This complex nature of DM and DE explains our inability to see DM or harvest DE for the last several decades. The positive complex DM is responsible for preserving the integrity of galaxies and all material systems. The negative complex charged DE induces a positive repelling force with the positively charged DM and contributes to the universe’s expansion. Both fields are Lorentz invariants in all directions and entangle the whole universe. The paper uses CFT to investigate zero-point energy, particle-wave duality, relativistic mass increase, and entanglement phenomenon and unifies Coulomb’s and Newton’s laws. The paper also verifies the existence of tachyons and explains the spooky action of quantum mechanics at a distance. The paper encourages further research into how CFT might resolve several physical mysteries in physics.
基金supported by National Key R&D Program of China(Nos.2023YFA1606904 and 2023YFA1606900)National Natural Science Foundation of China(No.12150006)+1 种基金Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400209)National Center for High-Level Talent Training in Mathematics,Physics,Chemistry,and Biology。
文摘This paper presents the design and optimization of a lutetium yttrium oxyorthosilicate(LYSO)crystal electromagnetic calorimeter(ECAL)for the DarkSHINE experiment,which aims to identify dark photons as potential mediators of dark forces.The ECAL design was evaluated through comprehensive simulations,focusing on optimizing dimensions,material selection,energy distribution,and energy resolution.The configuration consisted of 21×21×11 LYSO crystals,each measuring 2.5 cm×2.5 cm×4 cm,arranged in a staggered layout to enhance signal detection efficiency.A 4 GeV energy dynamic range was established to ensure accurate energy measurements without saturation,which is essential for background rejection and signal identification.A detailed digitization model was developed to simulate scintillation,silicon photomultiplier,and analog-to-digital converter behaviors,providing a realistic representation of the detector's performance.Additionally,the study assessed radiation damage in the ECAL region,emphasizing the importance of using radiation-resistant scintillators and silicon sensors.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(grant No.2024A1515012573)National key R&D Program of China(grant No.2020YFC2201600)+1 种基金National Natural Science Foundation of China(NSFC,grant No.12073088)National SKA Program of China(grant No.2020SKA0110402)。
文摘While cold dark matter is widely supported by a range of cosmological observations,it encounters several difficulties at smaller scales.These issues have prompted the investigation of various alternative dark matter candidates,leaving the question“What is dark matter?”still open.In this work,we propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant.We then place constraints on our new model using the Planck 2018 Cosmic Microwave Background(CMB)anisotropy measurements,Baryon Acoustic Oscillation measurements from the Dark Energy Spectroscopic Instrument(DESI),the Pantheon Plus(PP)compilation of Type Ia supernovae,and the Redshift Space Distortions(RSD)data from Gold 2018.The results show statistically significant signal for positive dark matter equation of state and square of sound speed w_(dm)=c_(s,dm)^(2)(10^(7) w_(dm)=4.0_(-2.3)^(+2.5)at the 95%confidence level)for the data combination CMB+DESI+PP+RSD.However,Bayesian evidence indicates that this data combination favors theΛCDM model with very strong evidence.
文摘Detailed and redundant measurements of dark matter properties have recently become available. To describe the observations we consider scalar, vector and sterile neutrino dark matter models. A model with vector dark matter is consistent with all current observations.
文摘The subject is the thermodynamics of dark matter, the Helmholtz free energy. The method of fluctuations leads to an estimate of the mass of a dark matter particle. The picture that emerges is that of a small-mass, degenerate, spinless boson. Contour integration produces dark matter equations of state.
文摘The subject is the thermodynamics of dark energy. Thermodynamically, the ratio of dark energy to CMR temperature has the units of entropy, has a well-defined numerical value at every moment of cosmological history, and increases in time monotonically without limit. The proposal is that it is the cosmological entropy, aka dark entropy. Discussion compares it to other notions of entropy. Dark entropy is a necessary prelude to DEH IV, which is about the thermodynamics of dark matter.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52175245)the Natural Science Foundation of Hubei Province (Grant No. 2021CFB462)。
文摘Health monitoring of underwater concrete facility systems is important in civil engineering. Unlike conventional manual inspection techniques, digital image processing offers a more convenient and effective approach, becoming an indispensable tool for structural inspection. Cracks, which are pervasive defects, are a central focus of structural deterioration research. However, the complexity of the marine environment poses challenges to underwater visibility.In this study, the underwater environment under controlled laboratory conditions is replicated, where varying turbidity and illumination conditions and images of concrete cracks are captured. An approach combining a defogging algorithm with guided and fast guided filtering techniques is proposed to enhance both natural underwater images and crack images captured through experimental photography. When applied to turbid crack images captured under two different suspension conditions, the method increases the information entropy(IE) by 32.92% and 17.92% and the underwater color image quality evaluation(UCIQE) by 35.76% and 18.36%, respectively. These results demonstrate its efficiency in enhancing image definition. The findings of this study could significantly impact the practical applications of image visualization and evaluation for underwater concrete cracks.
基金Supported by the National Natural Science Foundation of China(No.82371093,No.72342015)R&D Program of Beijing Municipal Education Commission(No.KZ202110025039).
文摘AIM:To compare the efficacy of different administration regimens of compound tropicamide eyedrops(CTE)for pupil dilation for children with dark iris.METHODS:A prospective,comparative,randomized interventional study was conducted.Children in Group 1 received CTE 3 times with a 3min interval between each application.Children in Group 2 received CTE 4 times with a 5min interval between each application.We measured their pupil diameters at baseline(pre-drug instillation)and 30min and 60min post-drug instillation and assessed the pupillary light reflex at 60min post-drug instillation.RESULTS:In total,194 eyes of 101 children were enrolled.The changes of pupil diameter at 30min and 60min post-drug instillation were 1.2±0.6 mm and 2.3±1.0 mm in Group 1,and 2.3±0.9 mm and 3.7±1.0 mm in Group 2,respectively.Group 2 showed a larger change in pupil size than Group 1 at 30min(P<0.01)and 60min(P<0.01).The effect of pupil dilation in Group 2 was 1.25 times that in Group 1.The change in pupil size was positively associated with age.A higher proportion of children in Group 1 had smaller pupil diameter and reactive pupils at the final time point,with only 33 children(33.7%)had final pupil size≥6.5 mm,and only 9 children(9.2%)had non-reactive pupils.Children in Group 2 achieved larger pupil diameter and more nonreactive pupils at the final time point,with 84 children(87.5%)had final pupil size≥6.5 mm,and only 22 children(22.9%)had reactive pupils.CONCLUSION:Increasing the frequency of compound tropicamide and lengthening the interval between eye drop applications can produce stronger mydriatic effects.
基金supported by the National Natural Science Foundation of China(32402523)the Science and Technology Program of Henan Province,China(232102111083,242102111120)the Natural Science Foundation of Henan Province,China(252300420179).
文摘While bagged flat peaches gain increasing consumer preference,the bagging process inhibits anthocyanin production and fruit coloration in most peach cultivars.Certain peach cultivars,including the rapidly expanding‘Zhongyoupan 9’,demonstrate a light-independent anthocyanin biosynthesis pattern and accumulate anthocyanins under artificial darkness.The underlying molecular mechanisms,however,remain unelucidated.This study examined two flat peach varieties:‘Zhongpan 17’,exhibiting light-dependent anthocyanin biosynthesis,and‘Zhongyoupan 9’,displaying light-independent anthocyanin biosynthesis.The pericarp of‘Zhongyoupan 9’contained substantially higher anthocyanin levels compared to‘Zhongpan 17’.Metabolomic analysis identified the marked increase in anthocyanins,particularly cyanidin-3-O-glucoside,as the primary factor in‘Zhongyoupan 9’coloration under artificial darkness.Transcriptomic analyses revealed that PpHY5(long hypocotyl 5)showed upregulation in‘Zhongyoupan 9’but downregulation in‘Zhongpan 17’,with its expression pattern correlating positively with color changes in both varieties.The role of PpHY5 in positively regulating anthocyanin biosynthesis was confirmed through reduced anthocyanin levels in peach fruits treated with a PpHY5 virus-induced gene-silencing construct.These findings suggest that the PpHY5 regulates red color development in‘Zhongyoupan 9’under artificial darkness.
基金supported by the National Natural Science Foundation of China under Grant No.11675143the National Key Research and Development Program of China under Grant No.2020YFC2201503。
文摘In this paper we consider a static spherically symmetric black hole(BH)embedded in a Dehnen-(1,4,0)-type dark matter(DM)halo in the presence of a cloud string.We examine and present data on how the core density of the DM halo parameter and the cloud string parameter affect BH attributes such as quasinormal modes(QNMs)and shadow cast.To do this,we first look into the effective potential of perturbation equations for three types of perturbation fields with different spins:massless scalar field,electromagnetic field and gravitational field.Then,using the sixth-order Wentzel-Kramers-Brillouin approximation,we examine QNMs of the BH disturbed by the three fields and derive quasinormal frequencies.The changes in QNM versus the core density parameter and the cloud string parameter for three disturbances are explored.We also investigate how the core density and the cloud string parameter affect the photon sphere and shadow radius.Interestingly,the study shows that the influence of Dehnen-type DM and cloud strings increases both the photon sphere and the shadow radius.Finally,we employ observational data from Sgr A^(*) and M87^(*) to set limitations on the BH parameters.
基金partially funded by the Horizontal Scientific Research Project of the National Astronomical Observatories of CAS(Grant No.E0900501)and the Theoretical Fundamental Research Special Project of the Changchun Observatory,National Astronomical Observatories,CAS(Grant No.Y990000205)。
文摘Research on the properties of neutron stars with dark energy is a particularly interesting yet unresolved problem in astrophysics.We analyze the influence of dark energy on the equation of state,the maximum mass,the surface gravitational redshift and the Keplerian frequency for the traditional neutron star and the hyperon star matter within the relativistic mean field theory,using the GM1 and TM1 parameter sets by considering the two flavor symmetries of SU(6)and SU(3)combined with the observations of PSR J1614-2230,PSR J0348+0432,PSR J0030+0451,RX J0720.4-3125,and 1E 1207.4-5209.It is found that the existence of dark energy leads to the softened equations of the state of the traditional neutron star and the hyperon star.The radius of a fixed-mass traditional neutron star(or hyperon star)with dark energy becomes smaller,which leads to increased compactness.The existence of dark energy can also enhance the surface gravitational redshift and the Keplerian frequency of traditional neutron stars and hyperon stars.The growth of the Keplerian frequency may cause the spin rate to speed up,which may provide a possible way to understand and explain the pulsar glitch phenomenon.Specifically,we infer that the mass and the surface gravitational redshift of PSR J1748-2446ad without dark energy for the GM1(TM1)parameter set are 1.141 M_(☉)(1.309 M_(☉))and 0.095(0.105),respectively.The corresponding values for the GM1(TM1)parameter set are 0.901 M_(☉)(1.072M_(☉))and 0.079(0.091)if PSR J1748-2446ad contains dark energy withα=0.05.PSR J1748-2446ad may be a low-mass pulsar with a lower surface gravitational redshift under our selected models.
基金partially supported by the National Key Research and Development Program of China(Nos.2016YFA0401904 and 2017YFA0701001)the State Key Laboratory of Nuclear Physics and Technology,Peking University(Nos.NPT2022ZZ01).
文摘Low dark current photocathode guns are highly desired for high-brightness continuous-wave operations.Direct-current superconducting radio-frequency(DC-SRF)gun,a hybrid photocathode gun combining a DC gap and an SRF cavity,effectively isolates the photocathode from the SRF cavity and offers significant advantages in terms of minimizing dark current levels.This paper presents an in-depth analysis of the dark current of a newly developed high-brightness DC-SRF photocathode gun(DC-SRF-Ⅱ gun).Particularly,a systematic experimental investigation of the dark current was conducted,and a comprehensive understanding of its formation was achieved through compliant simulations and measurements.Additionally,measures for attaining sub-nanoampere dark currents in the DC-SRF-Ⅱ gun are presented,including design considerations,cavity processing,assembly,and conditioning.The findings of this study establish a strong foundation for achieving high-performance operation of the DC-SRF-Ⅱ gun and provide a valuable reference for other photocathode guns.
基金supported by the National Natural Science Foundation of China (31371557 and 31571574)Wenzhou Basic Scientific Research Project (N20240009)。
文摘Transcription factors(TFs)play key roles in the regulatory network of leaf senescence.However,many nodes in this network remain unclear.To elucidate the mechanism of leaf senescence mediated by a rice TF,WRKY10,the expression of multiple senescence-related genes and physiological phenotypes were monitored in WRKY10-and VQ MOTIF-CONTAINING PROTEIN8(VQ8)-overexpressing plants and the wrky10 and vq8 mutants.Our results showed that WRKY10 positively regulates abscisic acid(ABA)-and dark-induced senescence(DIS)by directly regulating the expression of multiple senescence-related genes.The VQ8 protein,a repressor of WRKY10,negatively regulates WRKY10-mediated DIS.The WRKY10-VQ8 module fine-tunes the progression of DIS.ABA,methyl jasmonate,and H_(2)O_(2) accelerate WRKY10-mediated DIS,whereas ammonium nitrate and dithiothreitol delay WRKY10-mediated DIS.Further analysis revealed that WRKY10 and VQ8 interact with ABA RESPONSIVE ELEMENT BINDING FACTOR1(ABF1)or ABF2.VQ8 represses the transcriptional activity of ABF1 and ABF2.Overexpression of ABF1 or ABF2 accelerates ABA-and dark-induced senescence and H_(2)O_(2) accumulation in N.benthamiana leaves,and WRKY10 and VQ8 can inhibit either ABF1-or ABF2-induced cell necrosis.Taken together,WRKY10 integrates multiple senescence signals to establish an orderly progression of leaf senescence.The VQ8 protein acts as a brake on WRKY10-induced senescence and ABF1/2-induced cell death,preventing uncontrolled cell death.
文摘Understanding the nature of dark matter remains one of the most enigmatic and unresolved issues in astrophysics.Certain theoretical models address this by introducing a novel component to account for dark matter.In this study,we propose a new scalar field derived from string T-duality,where its associated density represents the density of the surrounding matter field,in the spherically symmetric and static medium.Our exploration reveals that this scalar field behaves as the baryonic fluid,characterized by a positive effective state equation,ωe>0.Furthermore,a detailed investigation demonstrates that this model satisfies all energy conditions beyond the event horizon of a central black hole.Considering the light deflection and radar echo delay suggests that in this scalar field,the dark matter grows up in the halo and surrounding regions of galaxy systems.This indicates that dark matter accumulates as an effective field outside the observable regions of galaxies.
基金supported by the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(Nos.2020R1A2C3003958 and 2021R1C1C2010169)the Basic Science Research Program(Priority Research Institute)through the NRF of Korea funded by the Ministry of Education(No.2021R1A6A1A10039823)the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2020R1A6C101B194).
文摘Hybrid organic-inorganic perovskite photodetectors have gained significant attention due to their superior potential for optoelectronic applications,offering various advantages such as low-cost processing,high charge carrier mobility,and lightweight properties.However,these perovskite photodetectors exhibit relatively low absorption in the near-infrared(NIR)range,which limits their potential applications.Here,to address this challenge,the integration of gold nanorods(Au NRs)utilizing localized surface plasmon resonance(LSPR)effects in the NIR range has been developed,leading to enhanced light absorption in the active region and higher photocurrent generation.Additionally,∼7.9 nm of thin polyethyleneimine ethoxylated(PEIE)interlayers were incorporated into the Au NR photodetectors,suppressing dark current by blocking charge injection.As a result,the synergistic effect of the Au NR/PEIE hybrid layer has led to a high-performance photodetector with a responsivity of 0.360 A/W and a detectivity of 1.81×10^(10) Jones,demonstrating a noticeable enhancement compared to the control device.Finite-difference time-domain(FDTD)simulations,morphological characterizations,and photoluminescence studies further support the mechanism for enhancing the performance of the device.We believe that our plasmon-enhanced protocol holds strong potential as a promising platform for perovskite optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Grant No.12326304,12326305,12071304)the Shenzhen Natural Science Fund(the Stable Support Plan Program)(Grant No.20220809163103001)+2 种基金the Natural Science Foundation of Henan Province(Grant No.232300420119)the Excellent Science and Technology Innovation Talent Support Program of ZUT(Grant No.K2023YXRC06)Funding for the Enhancement Program of Advantageous Discipline Strength of ZUT(2022)。
文摘We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain the Jacobi's elliptic solution of the defocusing Hirota equation,and solve the related linear matrix eigenvalue problem on elliptic function background.The elliptic N-dark soliton solution in terms of theta functions is constructed by the Darboux transformation and limit technique.The asymptotic dynamical behaviors for the elliptic N-dark soliton solution as t→±∞are studied.Through numerical plots of the elliptic one-,two-and three-dark solitons,the amplification effect on the velocity of elliptic dark solitons,and the compression effect on the soliton spatiotemporal distributions produced by the third-order dispersion and self-steepening terms are discussed.
基金Nguyen Tat Thanh University,Ho Chi Minh city,Vietnam,for supporting this study
文摘The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after illumination.This limitation is bypassed in round-the-clock photocatalytic architectures,which incorporate advanced charge storage to de-correlate pho-ton absorption and catalytic turnover time scales.The strategies involve defect-mediated trap states,multi-electron redox processes,radical-dependent stabilization,and an interfacial charge pool in Faradaic junctions to work together,leading to extended hydrogen evolution reaction(HER)in the dark.Long afterglow phosphorescent materials(e.g.,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+))incorporated in heterojunction architectures with type II or Z-scheme band alignments can also promote fast charge separation for energy storage and subsequently enable controlled release after light quenching by the phosphorescent emis-sion.Advances in band-structure engineering,plasmonic coupling,and redox-active interfacial design result in systems with extraordinary stability and catalytic activity under natural day-night cycles.These stable photocatalytic systems off er a fundamentally new strategy for effi cient and environmentally benign sunlight-driven fuel production,meeting both per-formance and sustainability challenges to renewable energy technologies.
基金supported by the National Natural Science Foundation of China(61774152),which are gratefully acknowledged.
文摘Avalanche photodiode(APD)is a kind of photodetector with important applications in optical communication,light detection and ranging(LIDAR)and other fields.APDs fabricated using the recently developed AlGaAsSb as the multiplication material exhibit excellent noise performance.In this work,we report a low-noise separate absorption,grading,charge,and multi-plication(SAGCM)InGaAs/AlGaAsSb APD operating at 1550 nm.A double-mesa structure was fabricated to reduce the dark cur-rent.Numerical simulations were conducted to compare two different mesa-structured APDs.By analyzing the electric field distri-bution,it was found that the electric field at the edge of the multiplication region in the double-mesa APD is nearly 100 kV/cm lower than that of the single-mesa structure.Experimental results demonstrate that after device punch-through,the double-mesa APD’s dark current can be reduced by up to four times compared to the single-mesa APD.Quantitative analysis of the dark current components in the AlGaAsSb APD further confirms that the low sidewall electric field in the double-mesa struc-ture effectively suppresses the trap-assisted tunneling.Additionally,noise measurements indicate a k-value of approximately 0.014,which is significantly lower than that of traditional multiplication materials.This work provides preliminary validation for further performance improvements in low noise and low dark current AlGaAsSb APDs.
