Web 2.0时代已经到来,而如何能让Web2.0网站有更好的用户体验以及更快的数据传输一直是开发者所面临的重要问题。Ajax作为Web2.0中的一个关键技术,其在提高用户体验、减少网络传输方面有着无可替代的作用;而另一个新生的MVC框架Stripes...Web 2.0时代已经到来,而如何能让Web2.0网站有更好的用户体验以及更快的数据传输一直是开发者所面临的重要问题。Ajax作为Web2.0中的一个关键技术,其在提高用户体验、减少网络传输方面有着无可替代的作用;而另一个新生的MVC框架Stripes,以其配置文件少、学习周期短,也正成为Java开发者的宠儿。正是基于此,文中提出了一种整合Stripes+Ajax的架构,目的是让开发人员以最快最简洁的方式进行Ajax开发,同时文中还提出了Stripes在Ajax中的多种数据传输格式,提出了多种Ajax数据传输方案。展开更多
The optical diffraction is a major means of minute diameter measurements. Since the light intensity of the diffraction fringe, mainly distributed in the central bright stripes, and that will lead to a relatively low S...The optical diffraction is a major means of minute diameter measurements. Since the light intensity of the diffraction fringe, mainly distributed in the central bright stripes, and that will lead to a relatively low SNR for the signal of the senior stripes. The traditional dark stripes extraction algorithm affected greatly by the noise. So this paper presents an algorithm that could effectively eliminate the gross errorcaused by the noise. Than by curve fitting the local signal of the diffraction pattern with the least square principle, the system could achieve a high measurement precision.展开更多
As to the horizontal stripes defect which exist on the surface of the high-grade automotive panels in continuous annealing process, an effective comprehensive control method is proposed on the basis of full considerat...As to the horizontal stripes defect which exist on the surface of the high-grade automotive panels in continuous annealing process, an effective comprehensive control method is proposed on the basis of full consideration of the equipment and technological features of continuous annealing line. With five field tests as basis, the generation mechanism of the defect was analysised in detail and the comprehensive control measures were put forward. According to actual situation, a detailed technical plan was worked out .Then the relevant technologies were applied to a 1850 continuous annealing line. The statistics shows that this program acquired good effects. The incidence of horizontal stripes defect decreased from 100% to 2.78%. Meanwhile, the surface quality of strip also improved effectively, which created a larger economic benefit.展开更多
Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off （Scan Line Corrector） ga...Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off （Scan Line Corrector） gap-filling methods of LLHM （Local Linear Histogram Matching） and AWLHM （Adaptive Window Linear Histogram Matching）, which leave stripes as a byproduct. To improve Landsat SLC-off images with stripes,we propose an algorithm involving some hypothetical stripe-crossing stitch lines using the mean pixel value of the stitch lines.展开更多
A method to remove stripes from remote sensing images is proposed based on statistics and a new image enhancement method.The overall processing steps for improving the quality of remote sensing images are introduced t...A method to remove stripes from remote sensing images is proposed based on statistics and a new image enhancement method.The overall processing steps for improving the quality of remote sensing images are introduced to provide a general baseline.Due to the differences in satellite sensors when producing images,subtle but inherent stripes can appear at the stitching positions between the sensors.These stitchingstripes cannot be eliminated by conventional relative radiometric calibration.The inherent stitching stripes cause difficulties in downstream tasks such as the segmentation,classification and interpretation of remote sensing images.Therefore,a method to remove the stripes based on statistics and a new image enhancement approach are proposed in this paper.First,the inconsistency in grayscales around stripes is eliminated with the statistical method.Second,the pixels within stripes are weighted and averaged based on updated pixel values to enhance the uniformity of the overall image radiation quality.Finally,the details of the images are highlighted by a new image enhancement method,which makes the whole image clearer.Comprehensive experiments are performed,and the results indicate that the proposed method outperforms the baseline approach in terms of visual quality and radiation correction accuracy.展开更多
There are some different opinions on the formation of striped migmatite. Many striped migmatites are distributed around the plutonic rocks in the core of hot dome in nature. This shows that the pressure of intrusive r...There are some different opinions on the formation of striped migmatite. Many striped migmatites are distributed around the plutonic rocks in the core of hot dome in nature. This shows that the pressure of intrusive rocks to wall rocks must play an important role in the formation of stripes. This paper, at first, discusses the effects of directional pressure (i. e. compressive stress from intrusive rock to wall rock) on particle migration and crystallization, and the physical mechanism of Ostwald maturation and its adjusting effect in crystalline growth. And then, on the basic principles of physics and chemistry, we lay down the stochastic evolutional rules of the formation of crystal nucleus, diffusion, crystallization and dissolution of leucosome (melt) particles; and,neglecting other restrictive conditions, we build an idealizedly simplified two-dimensional model of stochastic cellular automaton for the recrystallization of metamorphic rock under directional pressure, and realize it by writing a program of Windows on PC. Theoretical analyses and computer simulations show that, at the beginning, the free particles of leucosome are initially even distributed in the system and form many crystal nucleus ; then, the anisotropies of diffusion, crystallization and dissolution caused by the directional pressure together with the mechanisms of Ostwald maturation can make the nucleus successively grow to form lenses, unevenly disconnected stripes, and layer-stripe structure, which correspond to low, medium and high grades of metamorphism and migmatization, respectively; that is, the effect of the pressure of intrusive rock to wall rock alone can form streaked structure in migmatite. Moreover, cellular automaton, adopted in this paper, is a kind of discrete and local grid dynamic model, and is extremely suitable for simulating the evolution of spatiotemporal structure of real systems and analyzing micro-mechanism creating complex macro-phenomenon. We believe that cellular automata will have broad applications in the geosciences which is full of complicated natural phenomena.展开更多
For graphs G and H,the Ramsey number R(G,H)is the minimum integer N such that any coloring of the edges of the complete graph K_(N)in red or blue yields a red G or a blue H.Denote the union of t disjoint copies of a g...For graphs G and H,the Ramsey number R(G,H)is the minimum integer N such that any coloring of the edges of the complete graph K_(N)in red or blue yields a red G or a blue H.Denote the union of t disjoint copies of a graph F by tF.We call tK_(2)a stripe.In this paper,we completely determine Ramsey numbers of stripes versus trees and unicyclic graphs.Our result also implies that a tree is tK_(2)-good if and only if the independence number of this tree is no less than t.As an application,we improve the known Ramsey numbers of stars versus fan graphs.Moreover,we determine the bipartite Ramsey numbers of a connected bipartite graph versus stripes.展开更多
The phenomenon termed“zebra stripes”manifests as regular patterns in the energy-space(L shell)spectrum of energetic electrons(ranging from tens to hundreds ke V)within the inner radiation belt.These structures exhib...The phenomenon termed“zebra stripes”manifests as regular patterns in the energy-space(L shell)spectrum of energetic electrons(ranging from tens to hundreds ke V)within the inner radiation belt.These structures exhibit drift-periodic behavior and commonly arise from large-scale electric field perturbations near the substorm onsets.In this study,we introduce a composite electric field model and replicate the formation,structure,and evolution of zebra stripes using a bounce-averaged test particle code under this electric field model.High-resolution measurements of energetic electrons obtained from the Van Allen Probes and the recently launched Macao Science Satellites-1 are used as initial conditions and served to validate our test particle simulations.Comparative analyses between observed data and simulations demonstrate our test particle method's efficacy in capturing zebra stripes'general behavior.Moreover,the composite model proves capable of reproducing realistic variations in the electric field within the inner radiation belt to a certain extent.Nevertheless,subtle differences emerge in the flux strength and the positions of stripes.These disparities primarily stem from limitations inherent in the electric field model and the initial conditions of the simulation.Acknowledging that the model represents an average case,it is conceivable that real-world scenarios may deviate from the average,thereby introducing variations in the observed phenomena.展开更多
A novel fine spectral structure in solar radio bursts has been discovered using the Chashan broadband solar radio spectrometer at meter wavelengths(CBSm),an instrument of the Chinese Meridian Project-PhaseⅡ(CMP-Ⅱ).T...A novel fine spectral structure in solar radio bursts has been discovered using the Chashan broadband solar radio spectrometer at meter wavelengths(CBSm),an instrument of the Chinese Meridian Project-PhaseⅡ(CMP-Ⅱ).The structure features periodic narrow-band stripes with a typical recurrence time<1 s(occasionally reaching 8 s),often drifting from high to low frequencies and accompanied by absorptions,with trailing stripes appearing at the end of preceding ones.Some stripes exhibit periodic beaded(or pearl-like)enhancements with a periodicity of~0.1 s.The beaded stripes are reported for the first time ever.Data from the DAocheng Radio Telescope(DART)indicate a radio emission brightness temperature exceeding 10^(9)K,originating above brightening loops in active region AR 13664.We proposed a novel generation mechanism of the periodic stripes on the basis of the double plasma resonance(DPR)instability,and explained the beaded substructure in terms of modulation by low-frequency magnetohydrodynamic(MHD)waves.The study highlights the CBSm's capability to detect high-resolution fine spectral structures and offers novel insights into the emission mechanism and source characteristics of solar radio bursts.展开更多
“Zebra stripes”denote banded structures characterized by periodic peaks and valleys in the spectrograms of energetic electrons in the Earth's inner radiation belt and slot region.In contrast to previous investig...“Zebra stripes”denote banded structures characterized by periodic peaks and valleys in the spectrograms of energetic electrons in the Earth's inner radiation belt and slot region.In contrast to previous investigations primarily grounded in equatorial observations,this study presents two events exhibiting the evolution of electron zebra stripes within the South Atlantic Anomaly,as observed from the Macao Scientific Satellite-1 in low Earth orbit.Our findings affirm that the structural and evolutionary features of zebra stripes in both events accord with the drift echo hypothesis.The start time extrapolated from the electron spectrograms correlates with substorm onsets,consistent with prior conclusions.Notably,the duration of zebra stripe evolution during the event of June 5–6,2023,reaches an impressive 34.7 h,a markedly longer interval than findings from the Van Allen Probes.This discrepancy suggests that the observed lifetime of electron zebra stripes may not inherently reflect natural limitations but could be constrained by instrumental capabilities.The results implicate that high-energy-resolution detectors have the potential to significantly enhance our capacity to scrutinize the dynamics of the radiation belt.展开更多
The Earth's crust,the outer shell of the Earth,consists of continental crust and oceanic crust.Oceanic crust is created at the mid-oceanic ridge,where it is magnetized in the ambient field of the Earth.As new mate...The Earth's crust,the outer shell of the Earth,consists of continental crust and oceanic crust.Oceanic crust is created at the mid-oceanic ridge,where it is magnetized in the ambient field of the Earth.As new material is extruded,the crust spreads outward,retaining its magnetization.The reversal of the polarity of the Earth's magnetic field over geologic time leads to a pattern of striped magnetic anomalies.In this study,we carry out a preliminary evaluation on how data from the Macao Science Satellite-1(MSS-1),which has a low orbital inclination,influences inversion models of the oceanic crustal magnetic field when combined with data from the Swarm mission.For our modeling we use an equivalent source method based on a cubed-sphere grid.Our model captures the broad magnetic structure over the North Atlantic Ocean and demonstrates that the trend of magnetic stripes is consistent with the age frame of the oceanic crust.The amplitude of the radial magnetic field at 450 km the North Atlantic Ocean ranges from–11 nT to+8 nT.The addition of MSS-1 observations to Swarm data generates results consistent with the overall magnetic stripe pattern.The lack of short-wavelength scale structure reveals the limitation of high-altitude satellites in portraying fine features and hence lower-altitude observations would be required to delineate a more detailed crustal signature.It is expected to obtain a finer structure of oceanic magnetic stripes by combining low-altitude CHAMP field data and east-west gradient data derived from MSS-1 in future work.展开更多
Amplitude stripes imposed by ionospheric scintillation have been frequently observed in many of the equatorial nighttime acquisitions of the Advanced Land Observing Satellite(ALOS)Phased Array-type L-band Synthetic Ap...Amplitude stripes imposed by ionospheric scintillation have been frequently observed in many of the equatorial nighttime acquisitions of the Advanced Land Observing Satellite(ALOS)Phased Array-type L-band Synthetic Aperture Radar(PALSAR).This type of ionospheric artifact impedes PALSAR interferometric and polarimetric applications,and its formation cause,morphology,and negative influence have been deeply investigated.However,this artifact can provide an alternative opportunity in a positive way for probing and measuring ionosphere scintillation.In this paper,a methodology for measuring ionospheric scintillation parameters from PALSAR images with amplitude stripes is proposed.Firstly,sublook processing is beneficial for recovering the scattered stripes from a single-look complex image;the amplitude stripe pattern is extracted via band-rejection filtering in the frequency domain of the sublook image.Secondly,the amplitude spectrum density function(SDF)is estimated from the amplitude stripe pattern.Thirdly,a fitting scheme for measuring the scintillation strength and spectrum index is conducted between the estimated and theoretical long-wavelength SDFs.In addition,another key parameter,the scintillation index,can be directly measured from the amplitude stripe pattern or indirectly derived from the scintillation strength and spectrum index.The proposed methodology is fully demonstrated on two groups of PALSAR acquisitions in the presence of amplitude stripes.Self-validation is conducted by comparing the measured and derived scintillation index and by comparing the measurements of range lines and azimuth lines.Cross-validation is performed by comparing the PALSAR measurements with in situ Global Position System(GPS)measurements.The processing results demonstrate a powerful capability to robustly measure ionospheric scintillation parameters from space with high spatial resolution.展开更多
During February 15–16, 2014, the energetic electron spectrogram for four successive inner radiation belt crossing show clearly the electron zebra structures and their time evolution which last for about 17 h. Unfortu...During February 15–16, 2014, the energetic electron spectrogram for four successive inner radiation belt crossing show clearly the electron zebra structures and their time evolution which last for about 17 h. Unfortunately, the time of flight(TOF) in RBSPICE measurement is turned off below 3 RE, and the ion measurement is contaminated by electrons. Thus in this study we studied the differences between the ion and electron zebra stripe structures and their time evolution using simple theory and test particle simulation, combining the electron measurement from RBSIPICE onboard Van Allen Probes. Theoretical analysis predicts that the ion zebra stripe structures should lie at a higher energy range than the corresponding electron zebra stripe structures due to that the directions of gradient B drift and corotation E×B drift are the same for electrons while opposite for ions. Test particle simulation with the dipole magnetic field and Volland-Stern electric field model have shown that the ion and electron zebra stripe structures could be produced by the convection electric field penetrating into the inner magnetosphere in this event, with their time evolution determined by total drift velocity that are different for ions and electrons. The predicted differences between the ion and electron zebra stripe structures are partially verified through observation. The ion zebra stripe structures could have potential influence to the ring current.展开更多
To realize effective co-phasing adjustment in large-aperture sparse-aperture telescopes,a multichannel stripe tracking approach is employed,allowing simultaneous interferometric measurements of multiple optical paths ...To realize effective co-phasing adjustment in large-aperture sparse-aperture telescopes,a multichannel stripe tracking approach is employed,allowing simultaneous interferometric measurements of multiple optical paths and circumventing the need for pairwise measurements along the mirror boundaries in traditional interferometric methods.This approach enhances detection efficiency and reduces system complexity.Here,the principles of the multibeam interference process and construction of a co-phasing detection module based on direct optical fiber connections were analyzed using wavefront optics theory.Error analysis was conducted on the system surface obtained through multipath interference.Potential applications of the interferometric method were explored.Finally,the principle was verified by experiment,an interferometric fringe contrast better than 0.4 is achieved through flat field calibration and incoherent digital synthesis.The dynamic range of the measurement exceeds 10 times of the center wavelength of the working band(1550 nm).Moreover,a resolution better than one-tenth of the working center wavelength(1550 nm)was achieved.Simultaneous three-beam interference can be achieved,leading to a 50%improvement in detection efficiency.This method can effectively enhance the efficiency of sparse aperture telescope co-phasing,meeting the requirements for observations of 8-10 m telescopes.This study provides a technological foundation for observing distant and faint celestial objects.展开更多
FeSe is an Fe-based paramagnetic superconductor with the simplest structure.The competition between the Néel and stripe magnetic orders is believed to be one of the reasons for the absence of magnetic orders in F...FeSe is an Fe-based paramagnetic superconductor with the simplest structure.The competition between the Néel and stripe magnetic orders is believed to be one of the reasons for the absence of magnetic orders in FeSe.FeSe is recognized as a prototypical platform for competing magnetic interactions,including Néel,stripe,and staggered antiferromagnetic coupling.However,the correlations between these magnetic orders and how they change with varying environmental conditions require further study.Here,we calculated the magnetic order of monolayer FeSe in three diferent environments:pure one,with slight lattice distortion,and on SrTiO_(3) substrate,by frst principles calculations.We fnd that in the calculated dispersion relation E(q)between the spin spiral energy E and spin spiral vector q of the monolayer FeSe structure,the stripe magnetic order M(π/2,π/2)has the lowest energy,and there is a fat E(q)between the wave vector X(π/2,0)and Néel magnetic order 2X(π,0),which are the degenerate E(q)states.The ground state of M and the highest density of states around 2X may be the reason for the competition of two magnetic orders.The slight lattice distortion does not alter the magnetic properties of monolayer FeSe.When monolayer FeSe is attached to the SrTiO_(3)substrate,the degenerate E(q)is still retained;meanwhile,the energy of the 2X(π,0)state is closer to the M state,which may be one of the reasons for the increase of superconducting temperature in FeSe/SrTiO_(3).展开更多
The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe pa...The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe patterns in plants,while there is still limited knowledge about the genetic mechanisms underlying stripe coloration due to the lack of germplasm resources.In this study,we focused on a watermelon germplasm with colorless stripes,and genetic analysis revealed that the trait is controlled by a single recessive gene.The gene Clsc(Citrullus lanatus stripe coloration),which is responsible for the colorless stripe,was localized into a 147.6 kb region on Chr9 by linkage analysis in a large F2 mapping population.Further analysis revealed that the Cla97C09G175170 gene encodes the APRR2 transcription factor,plays a crucial role in determining the watermelon colorless stripe phenotype and was deduced to be related to chlorophyll synthesis and chloroplast development.Physiological experiments indicated that Cla97C09G175170 may significantly influence chloroplast development and chlorophyll synthesis in watermelon.The results of this study provide a better understanding of the molecular mechanism of stripe coloration in watermelon and can be useful in the development of marker-assisted selection(MAS)for new watermelon cultivars.展开更多
The diversity of rodents in Asian deserts is high.Nevertheless,little is known about their use of daily torpor and hibernation,which are employed by many small mammals worldwide for energy and water conservation to pe...The diversity of rodents in Asian deserts is high.Nevertheless,little is known about their use of daily torpor and hibernation,which are employed by many small mammals worldwide for energy and water conservation to permit survival under adverse environmental conditions.We quantified for the first time,using temperature transponders and data loggers,long-term torpor expression and patterns in sympatric desert hamsters Phodopus roborovskii,striped hamsters Cricetulus barabensis and 3-toed jerboas Dipus sagitta under controlled conditions.Animals were live-trapped in Inner Mongolia in August and held in captivity under short photoperiods and low ambient temperatures(T,s)for about 6 months.Both hamster species(~half of individuals)expressed spontaneous(food available)daily torpor.Daily torpor in desert hamsters was less frequent and shallower than that in striped hamsters,which also had longer torpor bouts during torpor at T 15.8±0.4℃.Only one individual jerboa entered hibernation spontaneously at T,6.2±0.5℃,but all hibernated after food deprivation.The 2 hamster species only slightly changed their body mass during the acclimation,whereas jerboas greatly increased their body mass by 27.9%during the first 2 months of acclimation probably as a preparation for the hibernating season.Our data show that short photoperiod and moderately low T,induces spontaneous daily torpor in the 2 hamster species,suggesting that it is used regularly in the wild.Hibernation in Jerboas occurred at T,6.2±0.5°C especially when food was withheld suggesting limited food availability is the proximate trigger of their hibernation.展开更多
Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and r...Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.展开更多
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), is an airborne disease. In China, it frequently develops initially in central Shaanxi and southwestern Gansu, and from there, inoculum spreads to ...Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), is an airborne disease. In China, it frequently develops initially in central Shaanxi and southwestern Gansu, and from there, inoculum spreads to the eastern wheat production regions. Field investigations have suggested that Pst could spread from the west to the east within central Shaanxi andthat Gansu could serve as the inoculum source for central Shaanxi, but there is no direct evidence for this hypothetical dispersal route. In the current study, 321 Pst isolates collected from central Shaanxi and Gansu in the 2019–2020 and2020–2021 winter wheat cropping seasons were genotyped using 23 pairs of KASP-SNP markers. The dispersion among subpopulations was analyzed using several approaches, and overall, the populations were found to exhibit high levels of genetic diversity. There was little genetic divergence(0.05>FST>0) within central Shaanxi. However, significant gene flow(Nm>4) driven by wind-oriented dispersal from west(Baoji) to east(Weinan) occurred. There was also gene flow among the 4 Gansu subpopulations of Tianshui, Longnan, Pingliang, and Qingyang. Migration of the pathogen occurred between central Shaanxi and Gansu. Migration from Gansu to central Shaanxi was major compared with that from central Shaanxi to Gansu that was minor. Genetic variation occurred among isolates, instead of among subpopulations and within isolates. Linkage disequilibrium revealed that there was strong genetic recombination in the subpopulations from Gansu and central Shaanxi. Therefore, the present study provides molecular evidence that Pst spread from west to east in central Shaanxi and showed that Gansu(especially Longnan and Tianshui) was one of the major origins of the pathogen inoculum of wheat stripe rust in central Shaanxi. The results revealed the west-to-east transmission route of wheat stripe rust in central Shaanxi, being used to guide integrated management of the disease.展开更多
文摘The optical diffraction is a major means of minute diameter measurements. Since the light intensity of the diffraction fringe, mainly distributed in the central bright stripes, and that will lead to a relatively low SNR for the signal of the senior stripes. The traditional dark stripes extraction algorithm affected greatly by the noise. So this paper presents an algorithm that could effectively eliminate the gross errorcaused by the noise. Than by curve fitting the local signal of the diffraction pattern with the least square principle, the system could achieve a high measurement precision.
文摘As to the horizontal stripes defect which exist on the surface of the high-grade automotive panels in continuous annealing process, an effective comprehensive control method is proposed on the basis of full consideration of the equipment and technological features of continuous annealing line. With five field tests as basis, the generation mechanism of the defect was analysised in detail and the comprehensive control measures were put forward. According to actual situation, a detailed technical plan was worked out .Then the relevant technologies were applied to a 1850 continuous annealing line. The statistics shows that this program acquired good effects. The incidence of horizontal stripes defect decreased from 100% to 2.78%. Meanwhile, the surface quality of strip also improved effectively, which created a larger economic benefit.
文摘Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off （Scan Line Corrector） gap-filling methods of LLHM （Local Linear Histogram Matching） and AWLHM （Adaptive Window Linear Histogram Matching）, which leave stripes as a byproduct. To improve Landsat SLC-off images with stripes,we propose an algorithm involving some hypothetical stripe-crossing stitch lines using the mean pixel value of the stitch lines.
文摘A method to remove stripes from remote sensing images is proposed based on statistics and a new image enhancement method.The overall processing steps for improving the quality of remote sensing images are introduced to provide a general baseline.Due to the differences in satellite sensors when producing images,subtle but inherent stripes can appear at the stitching positions between the sensors.These stitchingstripes cannot be eliminated by conventional relative radiometric calibration.The inherent stitching stripes cause difficulties in downstream tasks such as the segmentation,classification and interpretation of remote sensing images.Therefore,a method to remove the stripes based on statistics and a new image enhancement approach are proposed in this paper.First,the inconsistency in grayscales around stripes is eliminated with the statistical method.Second,the pixels within stripes are weighted and averaged based on updated pixel values to enhance the uniformity of the overall image radiation quality.Finally,the details of the images are highlighted by a new image enhancement method,which makes the whole image clearer.Comprehensive experiments are performed,and the results indicate that the proposed method outperforms the baseline approach in terms of visual quality and radiation correction accuracy.
文摘There are some different opinions on the formation of striped migmatite. Many striped migmatites are distributed around the plutonic rocks in the core of hot dome in nature. This shows that the pressure of intrusive rocks to wall rocks must play an important role in the formation of stripes. This paper, at first, discusses the effects of directional pressure (i. e. compressive stress from intrusive rock to wall rock) on particle migration and crystallization, and the physical mechanism of Ostwald maturation and its adjusting effect in crystalline growth. And then, on the basic principles of physics and chemistry, we lay down the stochastic evolutional rules of the formation of crystal nucleus, diffusion, crystallization and dissolution of leucosome (melt) particles; and,neglecting other restrictive conditions, we build an idealizedly simplified two-dimensional model of stochastic cellular automaton for the recrystallization of metamorphic rock under directional pressure, and realize it by writing a program of Windows on PC. Theoretical analyses and computer simulations show that, at the beginning, the free particles of leucosome are initially even distributed in the system and form many crystal nucleus ; then, the anisotropies of diffusion, crystallization and dissolution caused by the directional pressure together with the mechanisms of Ostwald maturation can make the nucleus successively grow to form lenses, unevenly disconnected stripes, and layer-stripe structure, which correspond to low, medium and high grades of metamorphism and migmatization, respectively; that is, the effect of the pressure of intrusive rock to wall rock alone can form streaked structure in migmatite. Moreover, cellular automaton, adopted in this paper, is a kind of discrete and local grid dynamic model, and is extremely suitable for simulating the evolution of spatiotemporal structure of real systems and analyzing micro-mechanism creating complex macro-phenomenon. We believe that cellular automata will have broad applications in the geosciences which is full of complicated natural phenomena.
基金supported by the National Natural Science Foundation of China(No.11931002).
文摘For graphs G and H,the Ramsey number R(G,H)is the minimum integer N such that any coloring of the edges of the complete graph K_(N)in red or blue yields a red G or a blue H.Denote the union of t disjoint copies of a graph F by tF.We call tK_(2)a stripe.In this paper,we completely determine Ramsey numbers of stripes versus trees and unicyclic graphs.Our result also implies that a tree is tK_(2)-good if and only if the independence number of this tree is no less than t.As an application,we improve the known Ramsey numbers of stars versus fan graphs.Moreover,we determine the bipartite Ramsey numbers of a connected bipartite graph versus stripes.
基金supported by the Major Project of Chinese National Programs for Fundamental Research and Development(Grant No.2021YFA0718600)the National Natural Science Foundation of China(Grant No.42230202)the Science and Technology Development Fund of Macao SAR(Grant No.0176/2023/RIA3)。
文摘The phenomenon termed“zebra stripes”manifests as regular patterns in the energy-space(L shell)spectrum of energetic electrons(ranging from tens to hundreds ke V)within the inner radiation belt.These structures exhibit drift-periodic behavior and commonly arise from large-scale electric field perturbations near the substorm onsets.In this study,we introduce a composite electric field model and replicate the formation,structure,and evolution of zebra stripes using a bounce-averaged test particle code under this electric field model.High-resolution measurements of energetic electrons obtained from the Van Allen Probes and the recently launched Macao Science Satellites-1 are used as initial conditions and served to validate our test particle simulations.Comparative analyses between observed data and simulations demonstrate our test particle method's efficacy in capturing zebra stripes'general behavior.Moreover,the composite model proves capable of reproducing realistic variations in the electric field within the inner radiation belt to a certain extent.Nevertheless,subtle differences emerge in the flux strength and the positions of stripes.These disparities primarily stem from limitations inherent in the electric field model and the initial conditions of the simulation.Acknowledging that the model represents an average case,it is conceivable that real-world scenarios may deviate from the average,thereby introducing variations in the observed phenomena.
基金supported by the National Natural Science Foundation of China(NNSFC)(Grant Nos.12103029,12303061,and 12203031)the Natural Science Foundation of Shandong Province(NSFSP)(Grant Nos.ZR2023QA074,and ZR2021QA033)the National Key R&D Program of China(Grant Nos.2022YFF0503002,and 2022YFF0503000)。
文摘A novel fine spectral structure in solar radio bursts has been discovered using the Chashan broadband solar radio spectrometer at meter wavelengths(CBSm),an instrument of the Chinese Meridian Project-PhaseⅡ(CMP-Ⅱ).The structure features periodic narrow-band stripes with a typical recurrence time<1 s(occasionally reaching 8 s),often drifting from high to low frequencies and accompanied by absorptions,with trailing stripes appearing at the end of preceding ones.Some stripes exhibit periodic beaded(or pearl-like)enhancements with a periodicity of~0.1 s.The beaded stripes are reported for the first time ever.Data from the DAocheng Radio Telescope(DART)indicate a radio emission brightness temperature exceeding 10^(9)K,originating above brightening loops in active region AR 13664.We proposed a novel generation mechanism of the periodic stripes on the basis of the double plasma resonance(DPR)instability,and explained the beaded substructure in terms of modulation by low-frequency magnetohydrodynamic(MHD)waves.The study highlights the CBSm's capability to detect high-resolution fine spectral structures and offers novel insights into the emission mechanism and source characteristics of solar radio bursts.
基金supported by the National Natural Science Foundation of China(Grant No.42230202)the Major Project of Chinese National Programs for Fundamental Research and Development(Grant No.2021YFA0718600)+1 种基金the Science and Technology Development Fund,Macao SAR(Grant No.SKL-LPS(MUST)-2024-2026)China Postdoctoral Science Foundation(Grant No.2020M670025)。
文摘“Zebra stripes”denote banded structures characterized by periodic peaks and valleys in the spectrograms of energetic electrons in the Earth's inner radiation belt and slot region.In contrast to previous investigations primarily grounded in equatorial observations,this study presents two events exhibiting the evolution of electron zebra stripes within the South Atlantic Anomaly,as observed from the Macao Scientific Satellite-1 in low Earth orbit.Our findings affirm that the structural and evolutionary features of zebra stripes in both events accord with the drift echo hypothesis.The start time extrapolated from the electron spectrograms correlates with substorm onsets,consistent with prior conclusions.Notably,the duration of zebra stripe evolution during the event of June 5–6,2023,reaches an impressive 34.7 h,a markedly longer interval than findings from the Van Allen Probes.This discrepancy suggests that the observed lifetime of electron zebra stripes may not inherently reflect natural limitations but could be constrained by instrumental capabilities.The results implicate that high-energy-resolution detectors have the potential to significantly enhance our capacity to scrutinize the dynamics of the radiation belt.
基金supported by the National Natural Science Foundation of China(42250101,42250102,42250103)the Macao Foundation,and the Science and Technology Development Fund,Macao SAR(File No.0002/2019/APD)。
文摘The Earth's crust,the outer shell of the Earth,consists of continental crust and oceanic crust.Oceanic crust is created at the mid-oceanic ridge,where it is magnetized in the ambient field of the Earth.As new material is extruded,the crust spreads outward,retaining its magnetization.The reversal of the polarity of the Earth's magnetic field over geologic time leads to a pattern of striped magnetic anomalies.In this study,we carry out a preliminary evaluation on how data from the Macao Science Satellite-1(MSS-1),which has a low orbital inclination,influences inversion models of the oceanic crustal magnetic field when combined with data from the Swarm mission.For our modeling we use an equivalent source method based on a cubed-sphere grid.Our model captures the broad magnetic structure over the North Atlantic Ocean and demonstrates that the trend of magnetic stripes is consistent with the age frame of the oceanic crust.The amplitude of the radial magnetic field at 450 km the North Atlantic Ocean ranges from–11 nT to+8 nT.The addition of MSS-1 observations to Swarm data generates results consistent with the overall magnetic stripe pattern.The lack of short-wavelength scale structure reveals the limitation of high-altitude satellites in portraying fine features and hence lower-altitude observations would be required to delineate a more detailed crustal signature.It is expected to obtain a finer structure of oceanic magnetic stripes by combining low-altitude CHAMP field data and east-west gradient data derived from MSS-1 in future work.
基金supported partly by the National Natural Science Foundation of China(NSFC)(62101568 and 62371460)the Scientific Research Program of the National University of Defense Technology(ZK21-06)the Taishan Scholars of Shandong Province(ts20190968)。
文摘Amplitude stripes imposed by ionospheric scintillation have been frequently observed in many of the equatorial nighttime acquisitions of the Advanced Land Observing Satellite(ALOS)Phased Array-type L-band Synthetic Aperture Radar(PALSAR).This type of ionospheric artifact impedes PALSAR interferometric and polarimetric applications,and its formation cause,morphology,and negative influence have been deeply investigated.However,this artifact can provide an alternative opportunity in a positive way for probing and measuring ionosphere scintillation.In this paper,a methodology for measuring ionospheric scintillation parameters from PALSAR images with amplitude stripes is proposed.Firstly,sublook processing is beneficial for recovering the scattered stripes from a single-look complex image;the amplitude stripe pattern is extracted via band-rejection filtering in the frequency domain of the sublook image.Secondly,the amplitude spectrum density function(SDF)is estimated from the amplitude stripe pattern.Thirdly,a fitting scheme for measuring the scintillation strength and spectrum index is conducted between the estimated and theoretical long-wavelength SDFs.In addition,another key parameter,the scintillation index,can be directly measured from the amplitude stripe pattern or indirectly derived from the scintillation strength and spectrum index.The proposed methodology is fully demonstrated on two groups of PALSAR acquisitions in the presence of amplitude stripes.Self-validation is conducted by comparing the measured and derived scintillation index and by comparing the measurements of range lines and azimuth lines.Cross-validation is performed by comparing the PALSAR measurements with in situ Global Position System(GPS)measurements.The processing results demonstrate a powerful capability to robustly measure ionospheric scintillation parameters from space with high spatial resolution.
基金supported by the Major Project of Chinese National Programs for Fundamental Research and Development(Grant No.2012CB825603)the National Natural Science Foundation of China(Grant Nos.41421003&41474148)+1 种基金the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(Grant No.XDA04060201)supported by JHU/APL(Subcontract No.937836)to the New Jersey Institute of Technology under NASA Prime(Contract No.NAS5-01072)
文摘During February 15–16, 2014, the energetic electron spectrogram for four successive inner radiation belt crossing show clearly the electron zebra structures and their time evolution which last for about 17 h. Unfortunately, the time of flight(TOF) in RBSPICE measurement is turned off below 3 RE, and the ion measurement is contaminated by electrons. Thus in this study we studied the differences between the ion and electron zebra stripe structures and their time evolution using simple theory and test particle simulation, combining the electron measurement from RBSIPICE onboard Van Allen Probes. Theoretical analysis predicts that the ion zebra stripe structures should lie at a higher energy range than the corresponding electron zebra stripe structures due to that the directions of gradient B drift and corotation E×B drift are the same for electrons while opposite for ions. Test particle simulation with the dipole magnetic field and Volland-Stern electric field model have shown that the ion and electron zebra stripe structures could be produced by the convection electric field penetrating into the inner magnetosphere in this event, with their time evolution determined by total drift velocity that are different for ions and electrons. The predicted differences between the ion and electron zebra stripe structures are partially verified through observation. The ion zebra stripe structures could have potential influence to the ring current.
文摘To realize effective co-phasing adjustment in large-aperture sparse-aperture telescopes,a multichannel stripe tracking approach is employed,allowing simultaneous interferometric measurements of multiple optical paths and circumventing the need for pairwise measurements along the mirror boundaries in traditional interferometric methods.This approach enhances detection efficiency and reduces system complexity.Here,the principles of the multibeam interference process and construction of a co-phasing detection module based on direct optical fiber connections were analyzed using wavefront optics theory.Error analysis was conducted on the system surface obtained through multipath interference.Potential applications of the interferometric method were explored.Finally,the principle was verified by experiment,an interferometric fringe contrast better than 0.4 is achieved through flat field calibration and incoherent digital synthesis.The dynamic range of the measurement exceeds 10 times of the center wavelength of the working band(1550 nm).Moreover,a resolution better than one-tenth of the working center wavelength(1550 nm)was achieved.Simultaneous three-beam interference can be achieved,leading to a 50%improvement in detection efficiency.This method can effectively enhance the efficiency of sparse aperture telescope co-phasing,meeting the requirements for observations of 8-10 m telescopes.This study provides a technological foundation for observing distant and faint celestial objects.
基金supported by the National Natural Science Foundation of China(Grant Nos.11204131 and 11974181)。
文摘FeSe is an Fe-based paramagnetic superconductor with the simplest structure.The competition between the Néel and stripe magnetic orders is believed to be one of the reasons for the absence of magnetic orders in FeSe.FeSe is recognized as a prototypical platform for competing magnetic interactions,including Néel,stripe,and staggered antiferromagnetic coupling.However,the correlations between these magnetic orders and how they change with varying environmental conditions require further study.Here,we calculated the magnetic order of monolayer FeSe in three diferent environments:pure one,with slight lattice distortion,and on SrTiO_(3) substrate,by frst principles calculations.We fnd that in the calculated dispersion relation E(q)between the spin spiral energy E and spin spiral vector q of the monolayer FeSe structure,the stripe magnetic order M(π/2,π/2)has the lowest energy,and there is a fat E(q)between the wave vector X(π/2,0)and Néel magnetic order 2X(π,0),which are the degenerate E(q)states.The ground state of M and the highest density of states around 2X may be the reason for the competition of two magnetic orders.The slight lattice distortion does not alter the magnetic properties of monolayer FeSe.When monolayer FeSe is attached to the SrTiO_(3)substrate,the degenerate E(q)is still retained;meanwhile,the energy of the 2X(π,0)state is closer to the M state,which may be one of the reasons for the increase of superconducting temperature in FeSe/SrTiO_(3).
基金supported by grants from theKey Scientific and Technological Project of Henan Province,China(222102110124)the Joint Fund of Science and Technology Research and Development Plan,Henan Province,China(222103810009)+4 种基金the National Natural Science Foundation of China(32172574,3217180560)the Funding of Joint Research on Agricultural Varieties Improvement of Henan Province,China(2022010503)the Major Science and Technology Project of Henan Province,China(221100110400)the Natural Science Foundation of Henan,China(222300420050)the Science and Technology Innovation Talent Support Program of Henan Province,China(23HASTIT034).
文摘The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe patterns in plants,while there is still limited knowledge about the genetic mechanisms underlying stripe coloration due to the lack of germplasm resources.In this study,we focused on a watermelon germplasm with colorless stripes,and genetic analysis revealed that the trait is controlled by a single recessive gene.The gene Clsc(Citrullus lanatus stripe coloration),which is responsible for the colorless stripe,was localized into a 147.6 kb region on Chr9 by linkage analysis in a large F2 mapping population.Further analysis revealed that the Cla97C09G175170 gene encodes the APRR2 transcription factor,plays a crucial role in determining the watermelon colorless stripe phenotype and was deduced to be related to chlorophyll synthesis and chloroplast development.Physiological experiments indicated that Cla97C09G175170 may significantly influence chloroplast development and chlorophyll synthesis in watermelon.The results of this study provide a better understanding of the molecular mechanism of stripe coloration in watermelon and can be useful in the development of marker-assisted selection(MAS)for new watermelon cultivars.
基金supported by grants from the National Natural Science Foundation of China to QSC(31470473 and 32260261)a Chinese Academy of Sciences Visiting Scientists Fellowship to FG.
文摘The diversity of rodents in Asian deserts is high.Nevertheless,little is known about their use of daily torpor and hibernation,which are employed by many small mammals worldwide for energy and water conservation to permit survival under adverse environmental conditions.We quantified for the first time,using temperature transponders and data loggers,long-term torpor expression and patterns in sympatric desert hamsters Phodopus roborovskii,striped hamsters Cricetulus barabensis and 3-toed jerboas Dipus sagitta under controlled conditions.Animals were live-trapped in Inner Mongolia in August and held in captivity under short photoperiods and low ambient temperatures(T,s)for about 6 months.Both hamster species(~half of individuals)expressed spontaneous(food available)daily torpor.Daily torpor in desert hamsters was less frequent and shallower than that in striped hamsters,which also had longer torpor bouts during torpor at T 15.8±0.4℃.Only one individual jerboa entered hibernation spontaneously at T,6.2±0.5℃,but all hibernated after food deprivation.The 2 hamster species only slightly changed their body mass during the acclimation,whereas jerboas greatly increased their body mass by 27.9%during the first 2 months of acclimation probably as a preparation for the hibernating season.Our data show that short photoperiod and moderately low T,induces spontaneous daily torpor in the 2 hamster species,suggesting that it is used regularly in the wild.Hibernation in Jerboas occurred at T,6.2±0.5°C especially when food was withheld suggesting limited food availability is the proximate trigger of their hibernation.
基金supported by the National Natural Science Foundation of China(32172020,31971884)the National Key Research and Development Program of China(2024YFD1201202,2024YFD1200402)+4 种基金the Sichuan Science and Technology Program(2022ZDZX0014,2023YFN0085)the Qinghai Provincial Key Laboratory of Crop Molecular Breeding(2023-1-1)the State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China(SKLKF202409)the Alliance of National and International Science Organizations for the Belt and Road Regions(ANSO-CR-KP-202205)the International Partnership Program of Chinese Academy of Sciences(077GJHZ2023028GC)。
文摘Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.
基金supported by the National Key R&D Program of China (2021YFD1401000)the National Natural Science Foundation of China (32072358 and 32272507)the Natural Science Basic Research Plan in Shaanxi Province, China (2020JZ-15)。
文摘Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), is an airborne disease. In China, it frequently develops initially in central Shaanxi and southwestern Gansu, and from there, inoculum spreads to the eastern wheat production regions. Field investigations have suggested that Pst could spread from the west to the east within central Shaanxi andthat Gansu could serve as the inoculum source for central Shaanxi, but there is no direct evidence for this hypothetical dispersal route. In the current study, 321 Pst isolates collected from central Shaanxi and Gansu in the 2019–2020 and2020–2021 winter wheat cropping seasons were genotyped using 23 pairs of KASP-SNP markers. The dispersion among subpopulations was analyzed using several approaches, and overall, the populations were found to exhibit high levels of genetic diversity. There was little genetic divergence(0.05>FST>0) within central Shaanxi. However, significant gene flow(Nm>4) driven by wind-oriented dispersal from west(Baoji) to east(Weinan) occurred. There was also gene flow among the 4 Gansu subpopulations of Tianshui, Longnan, Pingliang, and Qingyang. Migration of the pathogen occurred between central Shaanxi and Gansu. Migration from Gansu to central Shaanxi was major compared with that from central Shaanxi to Gansu that was minor. Genetic variation occurred among isolates, instead of among subpopulations and within isolates. Linkage disequilibrium revealed that there was strong genetic recombination in the subpopulations from Gansu and central Shaanxi. Therefore, the present study provides molecular evidence that Pst spread from west to east in central Shaanxi and showed that Gansu(especially Longnan and Tianshui) was one of the major origins of the pathogen inoculum of wheat stripe rust in central Shaanxi. The results revealed the west-to-east transmission route of wheat stripe rust in central Shaanxi, being used to guide integrated management of the disease.
