This essay argues that black and white cinema spawned a resistance to changing times that is still very present in the new generation of directors who follow classic film traditions while subverting them with consiste...This essay argues that black and white cinema spawned a resistance to changing times that is still very present in the new generation of directors who follow classic film traditions while subverting them with consistent narrative inventions.The Artist,the best picture Oscar award winner in 2012,is an example of this resistance as it pays homage to some of the greatest silent films of the first two or three decades of cinema history.“The Dark Side of the Screen”aims to underline that there is an unchanging power of the phantasmagoria so present in black and white movies,produced not only in the silent era but also in film noir through lighting effects and camera angles which characterize the work of major noir directors like Fritz Lang,Billy Wilder,and Orson Welles,who knew everything about the unutterable mysteries hidden on the dark side of the screen.展开更多
Arising from gravitational deflections of light rays by large-scale struc- tures in the Universe, weak-lensing effects have been recognized as one of the most important probes in cosmological studies. In this paper, w...Arising from gravitational deflections of light rays by large-scale struc- tures in the Universe, weak-lensing effects have been recognized as one of the most important probes in cosmological studies. In this paper, we review the main progress in weak-lensing analyses, and discuss the challenges in future investigations aiming to understand the dark side of the Universe with unprecedented precisions.展开更多
The discovery of the Higgs boson[1,2]marked the fulfillment of a key prediction within the standard model(SM)[3-7],which describes electroweak and strong interactions through the gauge symmetry M=UY(1 SU SUC(3).This m...The discovery of the Higgs boson[1,2]marked the fulfillment of a key prediction within the standard model(SM)[3-7],which describes electroweak and strong interactions through the gauge symmetry M=UY(1 SU SUC(3).This model is firmly established in quantum field theory(QFT)within Minkowski spacetime and extensively supported by experimental verification.Meanwhile,the direct detection of gravitational waves[8]has provided crucial confirmation for the Einstein’s general theory of relativity(GR)[9],which is characterized by the dynamics of Riemannian geometry in curved spacetime based on the general symmetry GL(1,3,R).展开更多
The axion,a leading dark matter(DM)candidate,can convert to photons in neutron star(NS)magnetospheres via the Primakoff effect,producing narrow-band radio emission that may be detected with high-sensitivity radio tele...The axion,a leading dark matter(DM)candidate,can convert to photons in neutron star(NS)magnetospheres via the Primakoff effect,producing narrow-band radio emission that may be detected with high-sensitivity radio telescopes.Previous studies searched for axion DM-induced signals from the isolated NS J0806.4-4123 using observations of the Meer KAT UHF band(544–1088 MHz),but excluded the 1051–1088 MHz subband to mitigate potential sideband contamination.To probe this unexplored parameter space,we reprocessed the 1000–1088 MHz subband data using optimized radio frequency interference(RFI)flagging and meticulous sideband calibration.The flux stability of the calibrators and the consistency with Meer KAT’s system equivalent flux density confirmed the reliability of the data within the 1000–1080 MHz range,while the 1080–1088 MHz subband was omitted due to flux anomalies.No significant signals exceeding 5σsignificance were detected within the axion mass range of 4.136–4.467μe V(1000–1080 MHz),including the previously unprobed range 4.347–4.467μe V(1051–1080 MHz).Our null detection sets new stringent constraints with Meer KAT NS data,excluding axion-photon couplings|g_(aγγ)|?8.2×10^(-12)Ge V^(-1)at the 95%confidence level for DM masses between 4.347 and 4.467μe V.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
Aristolochic acids （AAs）, previously rarely mentioned compounds, have been brought into the public eye several times since the beginning of this century; and currently, they have drawn even greater attention due to ...Aristolochic acids （AAs）, previously rarely mentioned compounds, have been brought into the public eye several times since the beginning of this century; and currently, they have drawn even greater attention due to their association with liver cancer, as was recently reported by Ng et al.（Ng et al., 2017）. The authors sequenced the whole exomes of 98patients with hepatocellular carcinomas （HCC） from Taiwan and reported that 78%of the cases carried the AAs mutational signature, A：T〉T：A transversion.展开更多
A combo photo released by the China National Space Administration(CNSA)on December 11 shows a crater on the dark side of the moon.This image was reportedly taken by Chang’e-1, the country’s first lunar probe,on Dece...A combo photo released by the China National Space Administration(CNSA)on December 11 shows a crater on the dark side of the moon.This image was reportedly taken by Chang’e-1, the country’s first lunar probe,on December 4. On December 12,a grand ceremony was held in Beijing to celebrate the success of the first stage of China’s lunar probe program.President Hu Jintao announced on the occasion that展开更多
上个世纪90年代,科学家曾经猜测,在月球的背面可能存在着大量的冰态的水,这个猜想曾经一度点燃了人们的登月狂想,英语甚至造出了human col-onies on the Moon这样的表达!现在,进一步的探索dampened(本义:使潮湿;使沮丧)hopes of finding...上个世纪90年代,科学家曾经猜测,在月球的背面可能存在着大量的冰态的水,这个猜想曾经一度点燃了人们的登月狂想,英语甚至造出了human col-onies on the Moon这样的表达!现在,进一步的探索dampened(本义:使潮湿;使沮丧)hopes of finding Large amounts of water on the dark side of the Moon。此句中的动词就足以让我们玩味一番。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
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
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
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
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
文摘This essay argues that black and white cinema spawned a resistance to changing times that is still very present in the new generation of directors who follow classic film traditions while subverting them with consistent narrative inventions.The Artist,the best picture Oscar award winner in 2012,is an example of this resistance as it pays homage to some of the greatest silent films of the first two or three decades of cinema history.“The Dark Side of the Screen”aims to underline that there is an unchanging power of the phantasmagoria so present in black and white movies,produced not only in the silent era but also in film noir through lighting effects and camera angles which characterize the work of major noir directors like Fritz Lang,Billy Wilder,and Orson Welles,who knew everything about the unutterable mysteries hidden on the dark side of the screen.
基金Supported by the National Natural Science Foundation of China
文摘Arising from gravitational deflections of light rays by large-scale struc- tures in the Universe, weak-lensing effects have been recognized as one of the most important probes in cosmological studies. In this paper, we review the main progress in weak-lensing analyses, and discuss the challenges in future investigations aiming to understand the dark side of the Universe with unprecedented precisions.
基金supported in part by the National Natural Science Foundation of China(12347103 and 11821505)the National Key Research and Development Program of China(2020YFC2201501)the Strategic Priority Research and special fund of the Chinese Academy of Sciences。
文摘The discovery of the Higgs boson[1,2]marked the fulfillment of a key prediction within the standard model(SM)[3-7],which describes electroweak and strong interactions through the gauge symmetry M=UY(1 SU SUC(3).This model is firmly established in quantum field theory(QFT)within Minkowski spacetime and extensively supported by experimental verification.Meanwhile,the direct detection of gravitational waves[8]has provided crucial confirmation for the Einstein’s general theory of relativity(GR)[9],which is characterized by the dynamics of Riemannian geometry in curved spacetime based on the general symmetry GL(1,3,R).
基金supported by the National Natural Science Foundation of China(NSFC,grant No.12220101003)the Leading Innovation and Entrepreneurship Team of Zhejiang Province of China(grant No.2023R01008)the National Key R&D Program of China No.2023YFE0110500。
文摘The axion,a leading dark matter(DM)candidate,can convert to photons in neutron star(NS)magnetospheres via the Primakoff effect,producing narrow-band radio emission that may be detected with high-sensitivity radio telescopes.Previous studies searched for axion DM-induced signals from the isolated NS J0806.4-4123 using observations of the Meer KAT UHF band(544–1088 MHz),but excluded the 1051–1088 MHz subband to mitigate potential sideband contamination.To probe this unexplored parameter space,we reprocessed the 1000–1088 MHz subband data using optimized radio frequency interference(RFI)flagging and meticulous sideband calibration.The flux stability of the calibrators and the consistency with Meer KAT’s system equivalent flux density confirmed the reliability of the data within the 1000–1080 MHz range,while the 1080–1088 MHz subband was omitted due to flux anomalies.No significant signals exceeding 5σsignificance were detected within the axion mass range of 4.136–4.467μe V(1000–1080 MHz),including the previously unprobed range 4.347–4.467μe V(1051–1080 MHz).Our null detection sets new stringent constraints with Meer KAT NS data,excluding axion-photon couplings|g_(aγγ)|?8.2×10^(-12)Ge V^(-1)at the 95%confidence level for DM masses between 4.347 and 4.467μe V.
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Aristolochic acids （AAs）, previously rarely mentioned compounds, have been brought into the public eye several times since the beginning of this century; and currently, they have drawn even greater attention due to their association with liver cancer, as was recently reported by Ng et al.（Ng et al., 2017）. The authors sequenced the whole exomes of 98patients with hepatocellular carcinomas （HCC） from Taiwan and reported that 78%of the cases carried the AAs mutational signature, A：T〉T：A transversion.
文摘A combo photo released by the China National Space Administration(CNSA)on December 11 shows a crater on the dark side of the moon.This image was reportedly taken by Chang’e-1, the country’s first lunar probe,on December 4. On December 12,a grand ceremony was held in Beijing to celebrate the success of the first stage of China’s lunar probe program.President Hu Jintao announced on the occasion that
文摘上个世纪90年代,科学家曾经猜测,在月球的背面可能存在着大量的冰态的水,这个猜想曾经一度点燃了人们的登月狂想,英语甚至造出了human col-onies on the Moon这样的表达!现在,进一步的探索dampened(本义:使潮湿;使沮丧)hopes of finding Large amounts of water on the dark side of the Moon。此句中的动词就足以让我们玩味一番。
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.
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.
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.
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.
