Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accel...Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.展开更多
A Gallai k-coloring is a k-edge-coloring of a complete graph in which there are no rainbow triangles.For given graphs G_(1),G_(2),G_(3)and nonnegative integers r,s,t with k=r+s+t,the k-colored Gallai-Ramsey number grk...A Gallai k-coloring is a k-edge-coloring of a complete graph in which there are no rainbow triangles.For given graphs G_(1),G_(2),G_(3)and nonnegative integers r,s,t with k=r+s+t,the k-colored Gallai-Ramsey number grk(K_(3):r·G_(1),s·G_(2),t·G_(3))is the minimum integer n such that every Gallai k-colored Kncontains a monochromatic copy of G_(1)colored by one of the first r colors or a monochromatic copy of G_(2)colored by one of the middle s colors or a monochromatic copy of G_(3)colored by one of the last t colors.In this paper,we determine the value of GallaiRamsey number in the case that G_(1)=B_(3)^(+),G_(2)=S_(3)^(+)and G_(3)=K_(3).Then the Gallai-Ramsey numbers grk(K_(3):B_(3)^(+)),grk(K_(3):S_(3)^(+))and grk(K_(3):K_(3))are obtained,respectively.Furthermore,the Gallai-Ramsey numbers grk(K_(3):r·B_(3)^(+),(k-r)·S_(3)^(+)),grk(K_(3):r·B_(3)^(+),(k-r)·K_(3))and grk(K_(3):s·S_(3)^(+),(k-s)·K_(3))are obtained,respectively.展开更多
The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory exp...The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory experiments and practical applications, cathode ablation has emerged as a critical concern. An optical diagnostic approach based on monochromatic radiation temperature measurement, utilizing plume emission spectra and the selection of an appropriate test band, has been successfully employed. This method provides an accurate temperature distribution across the cathode surface, offering a novel testing technique for the optimization and evaluation of magnetic plasma thruster designs.展开更多
We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acc...We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acceleration,which involves irradiating the narrow(submicrometer)side of a tape target.This results in the generation of a surface plasma wave and the subsequent acceleration of a proton bunch with high peak energy,quasi-monochromaticity,low energy bandwidth,and low divergence by the electrostatic field induced at the target rear.Up to now,the higher-Z(e.g.,carbon)ion bunches obtained with the peeler scheme have been found to exhibit an exponentially decaying thermal-like energy spectrum.To achieve a low energy bandwidth,we place a mass-limited carbon structure at the rear of the target.Using 3D particle-in-cell simulations,we show that a quasi-monochromatic carbon bunch can indeed be obtained.With a multi-PW laser pulse,10^(8) carbon ions with peak energy~110 MeV/u and with a divergence of 20° in the vertical plane and~1° in the horizontal plane can be generated.The quasi-monochromaticity,together with the low duration of the beam and in combination with the versatility of high-power laser facilities,should make this scheme attractive for practical applications such as heavy ion cancer therapy and higher-resolution diagnostics of extreme plasma states.展开更多
The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and d...The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and described.It is based on a double acousto-optical tunable filter(AOTF)and a specialized optical coupling system.The module provides wide field of view(FOV),absence of image distortions,random spectral access,fast spectral image acquisition at any wavelength in the visible range and accurate measurement of reflectance spectrum in each pixel of the image.Images of typical biomedical samples are presented and discussed.Their spectra are compared to the reference data.展开更多
Background:Effect of monochromatic green light illumination on embryo development has been reported in chickens.The avian pineal gland is an important photo-endocrine organ formed by a mediodorsal protrusion during em...Background:Effect of monochromatic green light illumination on embryo development has been reported in chickens.The avian pineal gland is an important photo-endocrine organ formed by a mediodorsal protrusion during embryonic development.However,the involvement of pineal gland in the light transduction process remains to be elucidated.In the present study,we investigated the influence of monochromatic green light on hatching time and explored the possible mechanism via pineal function.Results:A total of 600 eggs of White Leghorn(Shaver strain)were incubated under photoperiods of either 12 h of light and 12 h of darkness using monochromatic green light(12L:12D group)or 24 h of darkness(0L:24D group)for 18 d.Compared to 0L:24D group,the green light stimulation shortened the hatching time without extending the hatch window or impairing hatchability.The liver of embryos incubated in the 12L:12D light condition was heavier than those of the 0L:24D group on d 21 post incubation which may be linked to the observed increase in the serum concentration of insulin-like growth factor 1(IGF-1);primary secretion of the liver.Histological structure analysis of pineal gland demonstrated that the light stimulation increased follicle area,wall thickness and lumen area on d 10 and d 12 post incubation.Rhythmic function analysis demonstrated that three clock related genes(brain and muscle ARNT-like-1,BMAL1;circadian locomotor output cycles kaput,CLOCK;and cryptochrome-1,CRY1)and a melatonin rate-limiting enzyme related gene(arylalkylamine N-acetyltransferase,AANAT)were rhythmically expressed in the pineal gland of the 12L:12D group,but not in the 0L:24D group.Simultaneously,the light stimulation also increased the concentration of melatonin(MT),which was linked to hepatocyte proliferation and IGF-1 secretion in previous studies.Conclusions:The 12L:12D monochromatic green light stimulation during incubation shortened hatching time without impairing hatching performance.Pineal gland’s early histological development and maturation of its rhythmic function were accelerated by the light stimulation.It may be the key organ in the photo-endocrine axis that regulates embryo development,and the potential mechanism could be through enhanced secretion of MT in the 12L:12D group which promotes the secretion of IGF-1.展开更多
Space scientific exploration is rapidly becoming the primary battlefield for humankind to explore the universe.Countries worldwide have launched numerous space exploration satellites.Accurate calibration of the detect...Space scientific exploration is rapidly becoming the primary battlefield for humankind to explore the universe.Countries worldwide have launched numerous space exploration satellites.Accurate calibration of the detectors on the ground is a crucial element for space science satellites to obtain observational results.For the purpose of providing calibration for various satellite-borne detectors,multiple monochromatic X-rays facilities have been built at the National Institute of Metrology,P.R.China(NIM).These facilities mainly pertain to grating diffraction and Bragg diffraction,and the energy range of the produced monochromatic X-rays is 0.218–301 ke V.These facilities have a high performance in terms of energy stability,monochromaticity,and flux stability.The monochromaticity was greater than 3.0%.The energy stability of the facility is 0.02%at 25 ke V over 8 h,and the flux stability was within 1.0%at 25 ke V over 8 h.Calibration experiments on the properties of satellite-borne detectors,such as energy linearity,energy resolution,detection efficiency,and temperature response,can be conducted at the facilities.Thus far,the calibration of two satellites has been completed by the authors,and the work on three other satellites is in progress.This study will contribute to the advancement of X-ray astronomy the development of Chinese space science.展开更多
Illuminating conditions are crucial factors affecting the microalgal growth and biosynthesis.The effects of illuminating spectral quality on the growth and bio-component production of Nannochloris oculata were investi...Illuminating conditions are crucial factors affecting the microalgal growth and biosynthesis.The effects of illuminating spectral quality on the growth and bio-component production of Nannochloris oculata were investigated.The results indicated that a high proportion of Red-light enhanced the pigments and carbohydrate production but reduced those of the biomass and lipid.Mono-chromatic Blue-light has advantageous effects on lipid production compared with Red-and White-light.The optimal light spectrum for the protein production was the combination of Red-and Blue-light at a ratio of 4:3 or 5:2.Among the seven fatty acids identified from N.oculata,the contents of C16:0,C18:0,and C18:3(n-3)in the lipid were inhibited by the increased proportion of Red-light while those of C18:2(n-9),C16:2(n-6),and C20:0 were inhibited by Blue-light.Monochromatic Red-and Blue-light and their com-binations were proposed as a promising illuminating strategy for the large-scale cultivation aiming for various bio-components.展开更多
AIM: To investigate the value of computed tomography(CT) spectral imaging in the evaluation of intestinal hemorrhage.METHODS: Seven blood flow rates were simulated in vitro.Energy spectral CT and mixed-energy CT scans...AIM: To investigate the value of computed tomography(CT) spectral imaging in the evaluation of intestinal hemorrhage.METHODS: Seven blood flow rates were simulated in vitro.Energy spectral CT and mixed-energy CT scanswere performed for each rate(0.5,0.4,0.3,0.2,0.1,0.05 and 0.025 m L/min).The detection rates and the contrast-to-noise ratios(CNRs) of the contrast agent extravasation regions were compared between the two scanning methods in the arterial phase(AP) and the portal venous phase(PVP).Comparisons of the CNR values between the PVP and the AP were made for each energy level and carried out using a completely random t test.A χ2 test was used to compare the detection rates obtained from the two scanning methods.RESULTS: The total detection rates for energy spectral CT and mixed-energy CT in the AP were 88.57%(31/35) and 65.71%(23/35),respectively,and the difference was significant(χ2 = 5.185,P = 0.023); the total detection rates in the PVP were 100.00%(35/35) and 91.4%(32/35),respectively,and the difference was not significant(χ2 = 1.393,P = 0.238).In the AP,the CNR of the contrast agent extravasation regions was 3.58 ± 2.09 on the mixed-energy CT images,but the CNRs were 8.78 ± 7.21 and 8.83 ± 6.75 at 50 and 60 keV,respectively,on the single-energy CT images,which were significantly different(3.58 ± 2.09 vs 8.78 ± 7.21,P = 0.031; 3.58 ± 2.09 vs 8.83 ± 6.75,P = 0.029).In the PVP,the differences between the CNRs at 40,50 and 60 keV different monochromatic energy levels and the polychromatic energy images were significant(19.35 ± 10.89 vs 11.68 ± 6.38,P = 0.010; 20.82 ± 11.26 vs 11.68 ± 6.38,P = 0.001; 20.63 ± 10.07 vs 11.68 ± 6.38,P = 0.001).The CNRs at the different energy levels in the AP and the PVP were significantly different(t =-2.415,-2.380,-2.575,-2.762,-2.945,-3.157,-3.996 and-3.189).CONCLUSION: Monochromatic energy imaging spectral CT is superior to polychromatic energy images for the detection of intestinal hemorrhage,and the detection was easier in the PVP compared with the AP.展开更多
AIMTo expose rat retinal Müller cells to 530 nm monochromatic light and investigate the influence of varying light illumination times on basic fibroblast growth factor (bFGF) and transforming growth factor...AIMTo expose rat retinal Müller cells to 530 nm monochromatic light and investigate the influence of varying light illumination times on basic fibroblast growth factor (bFGF) and transforming growth factor-β1 (TGF-β1) expression.METHODSThree groups of rat retinal Müller cells cultured in vitro under a 530 nm monochromatic light were divided into 6, 12 and 24h experimental groups, while cells incubated under dark conditions served as the control group. The bFGF and TGF-β1 mRNA expression, protein levels and fluorescence intensity of the Müller cells were analyzed.RESULTSThe bFGF mRNA expression and protein levels were significantly upregulated in Müller cells in all three experimental groups compared with the control group (P<0.05), while that of TGF-β1 was downregulated (P<0.05). Also, bFGF expression was positively correlated, but TGF-β1 expression was negatively correlated with illumination time. The largest changes for both cytokines were seen in the 24h group. The changes in bFGF and TGF-β1 fluorescence intensity were highest in the 24h group, and significant differences were observed among the experimental groups (P<0.05).CONCLUSIONThe expressions of bFGF and TGF-β1 changed in a time-dependent manner in Müller cells exposed to 530 nm monochromatic light with 250 lx illumination intensity. Müller cells might play a role in the development of myopia by increasing bFGF expression or decreasing TGF-β1 expression. Changes in cytokine expression in retinal Müller cells may affect monochromatic light-induced myopia.展开更多
Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for ...Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.展开更多
The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross...The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by simulations.Based on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was demonstrated.Because of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is suppressed.By coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying protons.This enables the application of a well-defined energy neutron beam in an event-by-event scheme.展开更多
Effects of light intensity and quality of three kinds of LED monochromatic lights (blue, green, and red) on the growth of Skeletonema costatum are investigated in batch culture conditions. Seven light intensities (20,...Effects of light intensity and quality of three kinds of LED monochromatic lights (blue, green, and red) on the growth of Skeletonema costatum are investigated in batch culture conditions. Seven light intensities (20, 30, 40, 45, 50, 60 and 80 μmol·m-2·s-1) are used to evaluate the specific growth rate, spectrum absorption coefficient and saturated light intensity of LED monochromatic light. Results show that the growth rates of Skeletonema costatum increase with the enhanced light intensity;however, the light level beyond the saturation light intensity inhibited the growth of Skeletonema costatum. Compared with red and green light, the growth rate of Skeletonema costatum under blue light is higher within saturated light intensity, and saturated light intensity of LED monochromatic light is lower under blue light and higher under green light. It is concluded that under different monochromatic light, the saturated light intensity decreases and the growth rate increases with the increasing of spectrum absorption coefficient.展开更多
Degradation of Japanese lacquer caused by light irradiation was examined at various wavelengths. By exposing lacquer specimens to a narrow monochromatic light band isolated from dispersed polychromatic light emitted b...Degradation of Japanese lacquer caused by light irradiation was examined at various wavelengths. By exposing lacquer specimens to a narrow monochromatic light band isolated from dispersed polychromatic light emitted by a Xe lamp source, the wavelength sensitivity characteristics of lacquer degradation could be determined on the basis of radiant energy. Tame-Urushi (brown) lacquer displayed peak degradation maxima at 220 and 315 nm. A broad shoulder peak was also observed in UVA. For Shu-Urushi (cinnabar) lacquer, in addition to peaks in the UVA–UVB range, a large degree of degradation was observed following exposure to light in the visible range. Ao-Urushi (green) lacquer showed similar characteristics, although it was less prone to degradation. Similarly, Shin-Urushi (black) lacquer showed little change in response to light, although UV light caused limited degradation. These results indicate that along with the damage caused by UVA and UVB, visible light in the range 510 - 650 nm may also have a significant degradation effect. Our results provide experimental evidence that Japanese lacquer responds differently to light of various wavelengths and that specific wavelengths, including visible light, can cause significant degradation.展开更多
A general scheme for the investigation of scattering by a chiral sphere under arbitrary monochromatic laser beam illumination is presented.The scattered and internal fields are expanded by using appropriate spherical ...A general scheme for the investigation of scattering by a chiral sphere under arbitrary monochromatic laser beam illumination is presented.The scattered and internal fields are expanded by using appropriate spherical vector wave functions,and their expansion coefficients are determined by the boundary conditions and the projection method.Targeting multiple incidence forms such as Gaussian beam,Hermite–Gaussian beam,doughnut mode beam and zero-order Bessel beam,the influence and propagation of near-surface intensity field for a chiral sphere are analyzed.These properties are very important for studying the properties of chiral media,and for manipulating the optical tweezers and super-resolution imaging of particles.展开更多
Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and m...Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and micro solid particles. Equilibrium flow condition is supposed to be maintained and energy is varying which is continuously supplied by inner expanding surface. It is found that similarity solution exists under the constant initial density. The comparison between the solutions obtained in gravitating and non-gravitating medium is done. It is found that the shock strength increases with an increase in gravitational parameter or ratio of the density of solid particles to the initial density of the gas, whereas an increase in the radiation parameter has decaying effect on the shock waves.展开更多
A self-similar flow behind a cylindrical shock wave is studied under the action of monochromatic radiation in a rotational axisymmetric dusty gas. The dusty gas is taken to be a mixture of small solid particles and pe...A self-similar flow behind a cylindrical shock wave is studied under the action of monochromatic radiation in a rotational axisymmetric dusty gas. The dusty gas is taken to be a mixture of small solid particles and perfect gas,and solid particles are continuously distributed in the mixture. The similarity solutions are obtained and the effects of the variation of the radiation parameter, the ratio of the density of solid particles to the initial density of the gas, the mass concentration of solid particles in the mixture and the index for the time dependent energy law are investigated.It is observed that an increase in the radiation parameter has decaying effect on the shock waves; whereas the shock strength increases with an increase in the ratio of the density of solid particles to the initial density of the gas or the index for the time dependent energy law. Also, it is found that an increase in the radiation parameter has effect to decrease the flow variables except the density and the azimuthal component of fluid velocity. A comparison is also made between rotating and non-rotating cases.展开更多
Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when...Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when n 〉 13k - 15. In this note, we characterize all the 2-edge-colorings of Kn where each monochromatic k-connected subgraph has at most n - 2k ＋ 2 vertices for n ≥ 13k - 15.展开更多
Let G be an edge-colored graph. The monochromatic tree partition problem is to find the minimum number of vertex disjoint monochromatic trees to cover the all vertices of G. In the authors＇ previous work, it has been...Let G be an edge-colored graph. The monochromatic tree partition problem is to find the minimum number of vertex disjoint monochromatic trees to cover the all vertices of G. In the authors＇ previous work, it has been proved that the problem is NP-complete and there does not exist any constant factor approximation algorithm for it unless P= NP. In this paper the authors show that for any fixed integer r ≥ 5, if the edges of a graph G are colored by r colors, called an r-edge-colored graph, the problem remains NP-complete. Similar result holds for the monochromatic path （cycle） partition problem. Therefore, to find some classes of interesting graphs for which the problem can be solved in polynomial time seems interesting. A linear time algorithm for the monochromatic path partition problem for edge-colored trees is given.展开更多
As is well known, coherence does not distinguish the relative phase of a pair of real, sinusoidal time series;the coherence between them is always unity. This behavior can limit the applicability of coherence analysis...As is well known, coherence does not distinguish the relative phase of a pair of real, sinusoidal time series;the coherence between them is always unity. This behavior can limit the applicability of coherence analysis in the special case where the time series are band-limited (nearly-monoch- romatic) and where sensitivity to phase differences is advantageous. We propose a simple mod-ification to the usual formula for coherence in which the cross-spectrum is replaced by its real part. The resulting quantity behaves similarly to coherence, except that it is sensitive to relative phase when the signals being compared are strongly band-limited. Furthermore, it has a useful interpretation in terms of the zero-lag cross-correlation of real band-passed versions of the time series.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0530000)the Discipline Construction Foundation of“Double World-class Project”.
文摘Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.
基金Supported by the National Natural Science Foundation of China(12161073)。
文摘A Gallai k-coloring is a k-edge-coloring of a complete graph in which there are no rainbow triangles.For given graphs G_(1),G_(2),G_(3)and nonnegative integers r,s,t with k=r+s+t,the k-colored Gallai-Ramsey number grk(K_(3):r·G_(1),s·G_(2),t·G_(3))is the minimum integer n such that every Gallai k-colored Kncontains a monochromatic copy of G_(1)colored by one of the first r colors or a monochromatic copy of G_(2)colored by one of the middle s colors or a monochromatic copy of G_(3)colored by one of the last t colors.In this paper,we determine the value of GallaiRamsey number in the case that G_(1)=B_(3)^(+),G_(2)=S_(3)^(+)and G_(3)=K_(3).Then the Gallai-Ramsey numbers grk(K_(3):B_(3)^(+)),grk(K_(3):S_(3)^(+))and grk(K_(3):K_(3))are obtained,respectively.Furthermore,the Gallai-Ramsey numbers grk(K_(3):r·B_(3)^(+),(k-r)·S_(3)^(+)),grk(K_(3):r·B_(3)^(+),(k-r)·K_(3))and grk(K_(3):s·S_(3)^(+),(k-s)·K_(3))are obtained,respectively.
文摘The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory experiments and practical applications, cathode ablation has emerged as a critical concern. An optical diagnostic approach based on monochromatic radiation temperature measurement, utilizing plume emission spectra and the selection of an appropriate test band, has been successfully employed. This method provides an accurate temperature distribution across the cathode surface, offering a novel testing technique for the optimization and evaluation of magnetic plasma thruster designs.
基金the support of the Romanian Government and the European Union through the European Regional Development Fund–the Competitiveness Operational Programme (1/07.07.2016, COP, Grant ID No. 1334) Phases Ⅱthe Romanian Ministry of Research, Innovation and Digitalization: Program Nucleu Grant No. PN23210105+6 种基金supported by the IOSIN Funds for Research Infrastructures of National Interest funded by the Romanian Ministry of Research, Innovation and Digitalizationsupported by Project No. ELI-RO/DFG/2023_001 ARNPhot funded by the Institute of Atomic Physics (Romania), the European Union, the Romanian Governmentthe Health Program, within the project “Medical Applications of High-Power Lasers–Dr. LASER,” SMIS Code 326475by Grant Nos. ELI-RO/RDI/2024_14 SPARC and ELI-RO/RDI/2024_8 AMAPBMBF Grant No. 05P24PF2 (Germany)the EuroHPC Joint Undertaking for awarding us access to Karolina at IT4Innovations (VAB-TU), Czechia under Project No. EHPCREG-2023R02-006 (Grant No. DD-23-157)Ministry of Education, Youth and Sports of the Czech Republic through e-INFRA CZ (Grant ID No. 90140)
文摘We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acceleration,which involves irradiating the narrow(submicrometer)side of a tape target.This results in the generation of a surface plasma wave and the subsequent acceleration of a proton bunch with high peak energy,quasi-monochromaticity,low energy bandwidth,and low divergence by the electrostatic field induced at the target rear.Up to now,the higher-Z(e.g.,carbon)ion bunches obtained with the peeler scheme have been found to exhibit an exponentially decaying thermal-like energy spectrum.To achieve a low energy bandwidth,we place a mass-limited carbon structure at the rear of the target.Using 3D particle-in-cell simulations,we show that a quasi-monochromatic carbon bunch can indeed be obtained.With a multi-PW laser pulse,10^(8) carbon ions with peak energy~110 MeV/u and with a divergence of 20° in the vertical plane and~1° in the horizontal plane can be generated.The quasi-monochromaticity,together with the low duration of the beam and in combination with the versatility of high-power laser facilities,should make this scheme attractive for practical applications such as heavy ion cancer therapy and higher-resolution diagnostics of extreme plasma states.
基金supported by Grant Nos.13-02-12210 and 14-00-10420 of Russian Foundation of Basic Research.
文摘The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and described.It is based on a double acousto-optical tunable filter(AOTF)and a specialized optical coupling system.The module provides wide field of view(FOV),absence of image distortions,random spectral access,fast spectral image acquisition at any wavelength in the visible range and accurate measurement of reflectance spectrum in each pixel of the image.Images of typical biomedical samples are presented and discussed.Their spectra are compared to the reference data.
基金Financial support of this study was provided by The National Key Research and Development Program of China(grant number 2016YFD0500502)China Agriculture Research Systems(grant number CARS-40)+1 种基金Fundamental Research Funds for Central Non-profit Scientific Institution(grant number 2018-YWF-YB-20)Agricultural Science and Technology Innovation Program(grant number ASTIP-IAS04).
文摘Background:Effect of monochromatic green light illumination on embryo development has been reported in chickens.The avian pineal gland is an important photo-endocrine organ formed by a mediodorsal protrusion during embryonic development.However,the involvement of pineal gland in the light transduction process remains to be elucidated.In the present study,we investigated the influence of monochromatic green light on hatching time and explored the possible mechanism via pineal function.Results:A total of 600 eggs of White Leghorn(Shaver strain)were incubated under photoperiods of either 12 h of light and 12 h of darkness using monochromatic green light(12L:12D group)or 24 h of darkness(0L:24D group)for 18 d.Compared to 0L:24D group,the green light stimulation shortened the hatching time without extending the hatch window or impairing hatchability.The liver of embryos incubated in the 12L:12D light condition was heavier than those of the 0L:24D group on d 21 post incubation which may be linked to the observed increase in the serum concentration of insulin-like growth factor 1(IGF-1);primary secretion of the liver.Histological structure analysis of pineal gland demonstrated that the light stimulation increased follicle area,wall thickness and lumen area on d 10 and d 12 post incubation.Rhythmic function analysis demonstrated that three clock related genes(brain and muscle ARNT-like-1,BMAL1;circadian locomotor output cycles kaput,CLOCK;and cryptochrome-1,CRY1)and a melatonin rate-limiting enzyme related gene(arylalkylamine N-acetyltransferase,AANAT)were rhythmically expressed in the pineal gland of the 12L:12D group,but not in the 0L:24D group.Simultaneously,the light stimulation also increased the concentration of melatonin(MT),which was linked to hepatocyte proliferation and IGF-1 secretion in previous studies.Conclusions:The 12L:12D monochromatic green light stimulation during incubation shortened hatching time without impairing hatching performance.Pineal gland’s early histological development and maturation of its rhythmic function were accelerated by the light stimulation.It may be the key organ in the photo-endocrine axis that regulates embryo development,and the potential mechanism could be through enhanced secretion of MT in the 12L:12D group which promotes the secretion of IGF-1.
基金upported by the National Key R&D Plan of China(2016YFF0200802)Establishment of a standard device for air kerma in mammography X-rays(ANL1902)。
文摘Space scientific exploration is rapidly becoming the primary battlefield for humankind to explore the universe.Countries worldwide have launched numerous space exploration satellites.Accurate calibration of the detectors on the ground is a crucial element for space science satellites to obtain observational results.For the purpose of providing calibration for various satellite-borne detectors,multiple monochromatic X-rays facilities have been built at the National Institute of Metrology,P.R.China(NIM).These facilities mainly pertain to grating diffraction and Bragg diffraction,and the energy range of the produced monochromatic X-rays is 0.218–301 ke V.These facilities have a high performance in terms of energy stability,monochromaticity,and flux stability.The monochromaticity was greater than 3.0%.The energy stability of the facility is 0.02%at 25 ke V over 8 h,and the flux stability was within 1.0%at 25 ke V over 8 h.Calibration experiments on the properties of satellite-borne detectors,such as energy linearity,energy resolution,detection efficiency,and temperature response,can be conducted at the facilities.Thus far,the calibration of two satellites has been completed by the authors,and the work on three other satellites is in progress.This study will contribute to the advancement of X-ray astronomy the development of Chinese space science.
基金supported by the National Natural Sci-ence Foundation of China(Nos.41776156 and 42177459)the Open-End Funds of Jiangsu Key Laboratory of Ma-rine Bioresources and Environment(No.SH20201206).
文摘Illuminating conditions are crucial factors affecting the microalgal growth and biosynthesis.The effects of illuminating spectral quality on the growth and bio-component production of Nannochloris oculata were investigated.The results indicated that a high proportion of Red-light enhanced the pigments and carbohydrate production but reduced those of the biomass and lipid.Mono-chromatic Blue-light has advantageous effects on lipid production compared with Red-and White-light.The optimal light spectrum for the protein production was the combination of Red-and Blue-light at a ratio of 4:3 or 5:2.Among the seven fatty acids identified from N.oculata,the contents of C16:0,C18:0,and C18:3(n-3)in the lipid were inhibited by the increased proportion of Red-light while those of C18:2(n-9),C16:2(n-6),and C20:0 were inhibited by Blue-light.Monochromatic Red-and Blue-light and their com-binations were proposed as a promising illuminating strategy for the large-scale cultivation aiming for various bio-components.
文摘AIM: To investigate the value of computed tomography(CT) spectral imaging in the evaluation of intestinal hemorrhage.METHODS: Seven blood flow rates were simulated in vitro.Energy spectral CT and mixed-energy CT scanswere performed for each rate(0.5,0.4,0.3,0.2,0.1,0.05 and 0.025 m L/min).The detection rates and the contrast-to-noise ratios(CNRs) of the contrast agent extravasation regions were compared between the two scanning methods in the arterial phase(AP) and the portal venous phase(PVP).Comparisons of the CNR values between the PVP and the AP were made for each energy level and carried out using a completely random t test.A χ2 test was used to compare the detection rates obtained from the two scanning methods.RESULTS: The total detection rates for energy spectral CT and mixed-energy CT in the AP were 88.57%(31/35) and 65.71%(23/35),respectively,and the difference was significant(χ2 = 5.185,P = 0.023); the total detection rates in the PVP were 100.00%(35/35) and 91.4%(32/35),respectively,and the difference was not significant(χ2 = 1.393,P = 0.238).In the AP,the CNR of the contrast agent extravasation regions was 3.58 ± 2.09 on the mixed-energy CT images,but the CNRs were 8.78 ± 7.21 and 8.83 ± 6.75 at 50 and 60 keV,respectively,on the single-energy CT images,which were significantly different(3.58 ± 2.09 vs 8.78 ± 7.21,P = 0.031; 3.58 ± 2.09 vs 8.83 ± 6.75,P = 0.029).In the PVP,the differences between the CNRs at 40,50 and 60 keV different monochromatic energy levels and the polychromatic energy images were significant(19.35 ± 10.89 vs 11.68 ± 6.38,P = 0.010; 20.82 ± 11.26 vs 11.68 ± 6.38,P = 0.001; 20.63 ± 10.07 vs 11.68 ± 6.38,P = 0.001).The CNRs at the different energy levels in the AP and the PVP were significantly different(t =-2.415,-2.380,-2.575,-2.762,-2.945,-3.157,-3.996 and-3.189).CONCLUSION: Monochromatic energy imaging spectral CT is superior to polychromatic energy images for the detection of intestinal hemorrhage,and the detection was easier in the PVP compared with the AP.
文摘AIMTo expose rat retinal Müller cells to 530 nm monochromatic light and investigate the influence of varying light illumination times on basic fibroblast growth factor (bFGF) and transforming growth factor-β1 (TGF-β1) expression.METHODSThree groups of rat retinal Müller cells cultured in vitro under a 530 nm monochromatic light were divided into 6, 12 and 24h experimental groups, while cells incubated under dark conditions served as the control group. The bFGF and TGF-β1 mRNA expression, protein levels and fluorescence intensity of the Müller cells were analyzed.RESULTSThe bFGF mRNA expression and protein levels were significantly upregulated in Müller cells in all three experimental groups compared with the control group (P<0.05), while that of TGF-β1 was downregulated (P<0.05). Also, bFGF expression was positively correlated, but TGF-β1 expression was negatively correlated with illumination time. The largest changes for both cytokines were seen in the 24h group. The changes in bFGF and TGF-β1 fluorescence intensity were highest in the 24h group, and significant differences were observed among the experimental groups (P<0.05).CONCLUSIONThe expressions of bFGF and TGF-β1 changed in a time-dependent manner in Müller cells exposed to 530 nm monochromatic light with 250 lx illumination intensity. Müller cells might play a role in the development of myopia by increasing bFGF expression or decreasing TGF-β1 expression. Changes in cytokine expression in retinal Müller cells may affect monochromatic light-induced myopia.
基金National Natural Science Foundation of China(No.11805212)National Key Research and Development Program of China(No.2019YFE03080200)。
文摘Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.
基金supported by the National Natural Science Foundation of China(Nos.11961141004,11605119,11965004,12047567,and U1867212)the Jiangsu Natural Science Fund Youth Project(No.BK20160304)+1 种基金China Postdoctoral Science Foundation(No.2017M621818)the Ministry of Science and Technology(No.2020YFE0202001).
文摘The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by simulations.Based on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was demonstrated.Because of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is suppressed.By coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying protons.This enables the application of a well-defined energy neutron beam in an event-by-event scheme.
文摘Effects of light intensity and quality of three kinds of LED monochromatic lights (blue, green, and red) on the growth of Skeletonema costatum are investigated in batch culture conditions. Seven light intensities (20, 30, 40, 45, 50, 60 and 80 μmol·m-2·s-1) are used to evaluate the specific growth rate, spectrum absorption coefficient and saturated light intensity of LED monochromatic light. Results show that the growth rates of Skeletonema costatum increase with the enhanced light intensity;however, the light level beyond the saturation light intensity inhibited the growth of Skeletonema costatum. Compared with red and green light, the growth rate of Skeletonema costatum under blue light is higher within saturated light intensity, and saturated light intensity of LED monochromatic light is lower under blue light and higher under green light. It is concluded that under different monochromatic light, the saturated light intensity decreases and the growth rate increases with the increasing of spectrum absorption coefficient.
文摘Degradation of Japanese lacquer caused by light irradiation was examined at various wavelengths. By exposing lacquer specimens to a narrow monochromatic light band isolated from dispersed polychromatic light emitted by a Xe lamp source, the wavelength sensitivity characteristics of lacquer degradation could be determined on the basis of radiant energy. Tame-Urushi (brown) lacquer displayed peak degradation maxima at 220 and 315 nm. A broad shoulder peak was also observed in UVA. For Shu-Urushi (cinnabar) lacquer, in addition to peaks in the UVA–UVB range, a large degree of degradation was observed following exposure to light in the visible range. Ao-Urushi (green) lacquer showed similar characteristics, although it was less prone to degradation. Similarly, Shin-Urushi (black) lacquer showed little change in response to light, although UV light caused limited degradation. These results indicate that along with the damage caused by UVA and UVB, visible light in the range 510 - 650 nm may also have a significant degradation effect. Our results provide experimental evidence that Japanese lacquer responds differently to light of various wavelengths and that specific wavelengths, including visible light, can cause significant degradation.
基金Project supported by the National Natural Science Foundation of China(Grant No.61771385)the Industrial Research of Science and Technology Plan of Shaanxi Province,China(Grant No.2016GY-082)
文摘A general scheme for the investigation of scattering by a chiral sphere under arbitrary monochromatic laser beam illumination is presented.The scattered and internal fields are expanded by using appropriate spherical vector wave functions,and their expansion coefficients are determined by the boundary conditions and the projection method.Targeting multiple incidence forms such as Gaussian beam,Hermite–Gaussian beam,doughnut mode beam and zero-order Bessel beam,the influence and propagation of near-surface intensity field for a chiral sphere are analyzed.These properties are very important for studying the properties of chiral media,and for manipulating the optical tweezers and super-resolution imaging of particles.
文摘Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and micro solid particles. Equilibrium flow condition is supposed to be maintained and energy is varying which is continuously supplied by inner expanding surface. It is found that similarity solution exists under the constant initial density. The comparison between the solutions obtained in gravitating and non-gravitating medium is done. It is found that the shock strength increases with an increase in gravitational parameter or ratio of the density of solid particles to the initial density of the gas, whereas an increase in the radiation parameter has decaying effect on the shock waves.
文摘A self-similar flow behind a cylindrical shock wave is studied under the action of monochromatic radiation in a rotational axisymmetric dusty gas. The dusty gas is taken to be a mixture of small solid particles and perfect gas,and solid particles are continuously distributed in the mixture. The similarity solutions are obtained and the effects of the variation of the radiation parameter, the ratio of the density of solid particles to the initial density of the gas, the mass concentration of solid particles in the mixture and the index for the time dependent energy law are investigated.It is observed that an increase in the radiation parameter has decaying effect on the shock waves; whereas the shock strength increases with an increase in the ratio of the density of solid particles to the initial density of the gas or the index for the time dependent energy law. Also, it is found that an increase in the radiation parameter has effect to decrease the flow variables except the density and the azimuthal component of fluid velocity. A comparison is also made between rotating and non-rotating cases.
基金Supported by the National Natural Science Foundation of China(10701065 and 11101378)Zhejiang Provincial Natural Science Foundation(LY14A010009)
文摘Bollobas and Gyarfas conjectured that for n 〉 4（k - 1） every 2-edge-coloring of Kn contains a monochromatic k-connected subgraph with at least n - 2k ＋ 2 vertices. Liu, et al. proved that the conjecture holds when n 〉 13k - 15. In this note, we characterize all the 2-edge-colorings of Kn where each monochromatic k-connected subgraph has at most n - 2k ＋ 2 vertices for n ≥ 13k - 15.
基金Supported by the National Natural Science Foundation of China,PCSIRT and the"973"Program
文摘Let G be an edge-colored graph. The monochromatic tree partition problem is to find the minimum number of vertex disjoint monochromatic trees to cover the all vertices of G. In the authors＇ previous work, it has been proved that the problem is NP-complete and there does not exist any constant factor approximation algorithm for it unless P= NP. In this paper the authors show that for any fixed integer r ≥ 5, if the edges of a graph G are colored by r colors, called an r-edge-colored graph, the problem remains NP-complete. Similar result holds for the monochromatic path （cycle） partition problem. Therefore, to find some classes of interesting graphs for which the problem can be solved in polynomial time seems interesting. A linear time algorithm for the monochromatic path partition problem for edge-colored trees is given.
文摘As is well known, coherence does not distinguish the relative phase of a pair of real, sinusoidal time series;the coherence between them is always unity. This behavior can limit the applicability of coherence analysis in the special case where the time series are band-limited (nearly-monoch- romatic) and where sensitivity to phase differences is advantageous. We propose a simple mod-ification to the usual formula for coherence in which the cross-spectrum is replaced by its real part. The resulting quantity behaves similarly to coherence, except that it is sensitive to relative phase when the signals being compared are strongly band-limited. Furthermore, it has a useful interpretation in terms of the zero-lag cross-correlation of real band-passed versions of the time series.
