To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.T...To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.展开更多
A double-parabola monocapillary(DPM)was designed for laboratory x-ray sources,and its performance was evaluated through numerical simulations and experimental validation.A surface shape error model was developed to ch...A double-parabola monocapillary(DPM)was designed for laboratory x-ray sources,and its performance was evaluated through numerical simulations and experimental validation.A surface shape error model was developed to characterize the DPM surface profile,and ray-tracing methods were used to simulate key properties such as focal spot size,divergence,and transmission efficiency.The simulation results closely matched experimental measurements,validating the proposed model.This surface shape error simulation provides an efficient method for evaluating the impact of slope errors on DPM performance,offering insights for optimal design and precision manufacturing.展开更多
Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were...Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were analyzed using gas chromatography(GC),gas chromatography-mass spectrometry(GC–MS),and gas chromatography-isotope ratio mass spectrometry(GC-IRMS).Theδ^(13)C values of forty-three LHs were recognized and determined by comparing the GC and GC-IRMS methods.The results revealed significant differences inδ^(13)C distribution characteristics among different LH compounds.Theδ^(13)C variation of individual LHs in iso-paraffins showed the widest range,followed by cycloalkanes and aromatics,whereas theδ^(13)C variation in n-paraffins showed the narrowest range.Theδ^(13)C values of most individual LHs are primarily affected by the source facies and thermal evolution.Among them,c-1,3-dimethylcyclohexane(c-1,3DMCH)is mainly sourced from higher plants but may also form through abiotic mechanisms such as catalysis or cyclization.Theδ^(13)C values of c-1,3DMCH(δ^(13)Cc-1,3DMCH)primarily exhibit parental genetic characteristics,enabling effective distinction of oil from different source facies.Specifically,theδ^(13)Cc-1,3DMCH in marine oils,lacustrine oils,terrigenous oils,and coal-formed oils are<–22‰,from–22‰to−20.2‰,from−20.2‰to−18.4‰,and>−18.4‰,respectively.Moreover,maturity is the primary controlling factor forδ^(13)C values of 3MC7(δ^(13)C3MC7,3MC7:3-methylheptane),while the source facies serve as a secondary influence.The plot ofδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 was introduced to classify source facies.Asδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 increase,the source facies transits from marine to lacustrine,then terrigenous,and finally coal facies.Additionally,increasingδ^(13)C3MC7 indicates a relative increase in maturity.Therefore,theδ^(13)Cc-1,3DMCH vs.δ^(13)C3MC7 plot serves as an effective tool for distinguishing source facies and assessing relative maturity.展开更多
Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing th...Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing the size of micro light sources and enhancing optical resolution,the efficient and simple fabrication of ultra-high-resolution micro light sources remains challenging due to its reliance on precise micro-nano processing technology and advanced processing equipment.In this study,a simple approach for the efficient fabrication of submicron light sources is proposed,namely shadow-assisted sidewall emission(SASE)technology.The SASE utilizes the widely adopted UV photolithography process,employing metal shadow modulation to precisely control the emission of light from polymer sidewalls,thereby obtaining photoluminescent light sources with submicron line widths.The SASE eliminates the need for complex and cumbersome manufacturing procedures.The effects of process parameters,including exposure dose,development time,and metal film thickness,on the linewidth of sources are investigated on detail.It is successfully demonstrated red,green,and blue submicron light sources.Finally,their potential application in the field of optical anti-counterfeiting is also demonstrated.We believe that the SASE proposed in this work provides a novel approach for the preparation and application of micro light sources.展开更多
Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optim...Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.展开更多
As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Bei...As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.展开更多
Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As...Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As part of its on-going efforts to establish a centralized scientific data management platform,HLS is in the process of developing a test sys-tem that covers the entire lifecycle of scientific data,including data generation,acquisition,processing,analysis,and de-struction.However,the instruments used in the soft X-ray microscopy experimental station rely on commercial propriet-ary software for data acquisition and processing.We developed a semi-automatic data acquisition program to facilitate the integration of soft X-ray microscopy stations into a centralized scientific data management platform.Additionally,we cre-ated an online data processing platform to assist users in analyzing their scientific data.The system we developed and de-ployed meets the design requirements,successfully integrating the soft X-ray microscopy station into the full lifecycle management of scientific data.展开更多
A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies pe...A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.展开更多
We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after altern...We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism colors were highly consistent of L＊D65∈（43.47, 46.75）, C＊D65∈（65.20, 68.80） and ho＊D65∈（138.10, 140.23）. We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the color of jadeite-jade green might be slightly influenced by alternating of the light sources.展开更多
BACKGROUND Conventionally, the low luminous intensity, low image resolution, and difficulty in operation have been reported with the ultrathin endoscope. However, it has markedly advanced recently. The improvement of ...BACKGROUND Conventionally, the low luminous intensity, low image resolution, and difficulty in operation have been reported with the ultrathin endoscope. However, it has markedly advanced recently. The improvement of the diagnostic ability is expected.AIM To compare the early gastric cancer diagnostic ability of an ultrathin endoscope loaded with a laser light source and that of the conventional endoscope.METHODS The target subjects were 375 consecutive patients who underwent endoscopy at our hospital for post-endoscopic submucosal dissection follow-up of gastric cancer from January to August 2018. During endoscopy, the ultrathin endoscope was used in 140 patients(37.3%), and the conventional endoscope was used in235 patients(62.7%). Patient background was adjusted using the propensity score matching method, and gastric cancer detection ability was evaluated in the two groups.RESULTS The gastric cancer detection rate was 7.8% in the ultrathin endoscope group and7.0% in the conventional endoscope group, and the mean intragastric observation time was 4.1 ± 1.7 min in the ultrathin endoscope group and 4.1 ± 1.9 min in the conventional endoscope group, showing no significant differences between the groups. Moreover, the biopsy implementation rate was 31.8% in the ultrathin endoscope group and 41.1% in the conventional endoscope group, and the biopsy prediction rate was 17.9% and 13.2%, respectively, showing no significant differences between the groups.CONCLUSION The gastric cancer diagnostic ability of the ultrathin endoscope loaded with a laser light source was comparable to that of the conventional endoscope. The observation time was also comparable. Thus, endoscopy using the ultrathin endoscope loaded with the laser light source would be the first option in screening examinations of gastric cancer due to its low invasion.展开更多
Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative s...Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative system concepts in X-ray and computer tomography. This paper proposes a novel electron beam focusing, shaping,and deflection electron gun for distributed X-ray sources.The electron gun uses a dispenser cathode as an electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflection. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. Two identical half-rectangle opening electrodes are controlled by adjusting the potential of the two electrodes to control the electron beam trajectory, and then, multifocal spots are obtained on the anode target. The electron gun can increase the spatial density of the distributed X-ray sources, thereby improving the image quality. The beam experimental results show that the focal spot sizes of the deflected(deflected amplitude 10.5 mm)and non-deflected electron beams at full width at half maximum are 0.80 mm 90.50 mm and 0.55 mm 90.40 mm, respectively(anode voltage 160 kV; beam current 30 mA). The imaging experimental results demonstrate the excellent spatial resolution and time resolution of an imaging system built with the sources, which has an excellent imaging effect on a field-programmable gate array chip and a rotating metal disk.展开更多
A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,w...A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.展开更多
An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-o...An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.展开更多
A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were construc...A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were constructed based on images captured under four single light sources.Reconstruction image 1 was constructed by fusing greyscale versions of the original images into one image,and Reconstruction image2 was constructed based on the differences between the images captured under the different light sources.Subsequently,the four original images and two reconstructed images were input into the convolutional neural network AlexNet to recognize the density range in three cases:-1.5(clean coal) and+1.5 g/cm^(3)(non-clean coal);-1.8(non-gangue) and+1.8 g/cm^(3)(gangue);-1.5(clean coal),1.5-1.8(middlings),and+1.8 g/cm^(3)(gangue).The results show the following:(1) The reconstructed images,especially Reconstruction image 2,can effectively improve the recognition accuracy for the coal density range compared with images captured under single light source.(2) The recognition accuracies for gangue and non-gangue,clean coal and non-clean coal,and clean coal,middlings,and gangue reached88.44%,86.72% and 77.08%,respectively.(3) The recognition accuracy increases as the density moves further away from the boundary density.展开更多
The different reflection characteristics of the surface of tin steel strips and the different speeds of the tinning line demand an adaptive illumination light source for online machine vision inspection. This light so...The different reflection characteristics of the surface of tin steel strips and the different speeds of the tinning line demand an adaptive illumination light source for online machine vision inspection. This light source can be integrated with a time delay integration charge-coupled device （TDI CCD ） to capture the images of moving objects and facilitate inspection of the surface quality of tin steel strips. On-site application show the effectiveness of the TDI camera with the adaptive illumination light source in detecting the surface defects on tin steel strips of three different materials and with different tin coating weights.展开更多
Aiming at the problem that the calibration results of the transmissometers cannot be traced to the meteorological optical range(MOR) defined by the World Meteorological Organization(WMO). We designed an indoor calibra...Aiming at the problem that the calibration results of the transmissometers cannot be traced to the meteorological optical range(MOR) defined by the World Meteorological Organization(WMO). We designed an indoor calibration light source of the transmissometers based on spatial light modulation, focusing on the design of a non-intersecting CzernyTurner spectroscopic system which achieved a spectral resolution of less than 1 nm in the range from 380 nm to 780 nm. Then, the calibration light source’s spectrum matching model is established and the digital micromirror device(DMD)’s surface illuminance distribution law is simulated and analyzed. Finally, the MOR error of the calibrated light source is inverted. The results show that the simulation spectrum error of the 2 700 K absolute color temperature is below ±7.4% in the wavelength range from 380 nm to 780 nm, and the MOR error meets the requirements of the International Civil Aviation Organization in 40-2 000 m of MOR.展开更多
With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterili...With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterilization characters of high power integrated light sources(ILSs) haven’t been widely investigated before utilizing in public sanitary security. In this work,by integrating up to 195 UVC-LED chips, high power UVC-LED ILSs with a light output power(LOP) of 1.88 W were demonstrated. The UVC-LED ILSs were verified to have efficient and rapid sterilization capability, which have achieved more than99.9% inactivation rate of several common pathogenic microorganisms within 1 s. In addition, the corresponding air sterilization module based on them was also demonstrated to kill more than 97% of Staphylococcus albus in the air of 20 m3 confined room within 30 min. This work demonstrates excellent sterilization ability of UVC-LED ILSs with high LOP, revealing great potential of UVC-LEDs in sterilization applications in the future.展开更多
Energy optimization management can make fuel cell truck(FCT)power system more efficient,so as to improve vehicle fuel economy.When the structure of power source system and the torque distribution strategy are determin...Energy optimization management can make fuel cell truck(FCT)power system more efficient,so as to improve vehicle fuel economy.When the structure of power source system and the torque distribution strategy are determined,the essence is to find the reasonable distribution of electric power between the fuel cell and other energy sources.The paper simulates the assistance of the intelligent transport system(ITS)and carries out the eco-velocity planning using the traffic signal light.On this basis,in order to further improve the energy efficiency of FCT,a model predictive control(MPC)-based energy source optimization management strategy is innovatively developed,which uses Dijkstra algorithm to achieve the minimization of equivalent hydrogen consumption.Under the scenarios of signalized intersections,based on the planned eco-velocity,the off-line simulation results show that the proposed MPC-based energy source management strategy(ESMS)can reduce hydrogen consumption of fuel cell up to 7%compared with the existing rule-based ESMS.Finally,the Hardware-in-the-Loop(HiL)simulation test is carried out to verify the effectiveness and real-time performance of the proposed MPC-based energy source optimization management strategy for the FCT based on eco-velocity planning with the assistance of traffic light information.展开更多
Several experiments are performed on the ShenGuang-Ⅱ laser facility to investigate an x-ray source and test radiography concepts. X-ray lines emitted from laser-produced plasmas are the most practical means of genera...Several experiments are performed on the ShenGuang-Ⅱ laser facility to investigate an x-ray source and test radiography concepts. X-ray lines emitted from laser-produced plasmas are the most practical means of generating these high intensity sources. By using a time-integrated space-resolved keV spectroscope and pinhole camera, potential helium-like titanium Kα x-ray backlighting （radiography） line source is studied as a function of laser wavelength, ratio of pre-pulse intensity to main pulse intensity, and laser intensity （from 7.25 to ～ 11.3 × 10^15 W/cm2）. One-dimensional radiography using a grid consisting of 5 #m Au wires on 16 μm period and the pinhole-assisted point projection is tested. The measurements show that the size of the helium-like titanium Ka source from a simple foil target is larger than 100 ~m, and relative x-ray line emission conversion efficiency ~x from the incident laser light energy to helium- like titanium K-shell spectrum increases significantly with pre-pulse intensity increasing, increases rapidly with laser wavelength decreasing, and increases moderately with main laser intensity increasing. It is also found that a gold gird foils can reach an imaging resolution better than 5-μm featured with high contrast. It is further demonstrated that the pinhole-assisted point projection at such a level will be a novel two-dimensional imaging diagnostic technique for inertial confinement fusion experiments.展开更多
An experiment with thin titanium foils irradiated by two pulses delayed in time is conducted on the bnenguang-Il laser facility. A prepulse induces an underdense plasma, 2-ns later a main pulse （λL ≈ 0.35 μm, EL ...An experiment with thin titanium foils irradiated by two pulses delayed in time is conducted on the bnenguang-Il laser facility. A prepulse induces an underdense plasma, 2-ns later a main pulse （λL ≈ 0.35 μm, EL ≈120 J, τL ≈100 ps） is injected into the underdense plasma and produces strong line emission from the titanium K shell （i.e., Hea at 4.7 keV）. Data show that the intensity of 4.7-keV X-ray emission with the prepulse is approximately twice more than without the prepulse, and can be used as a backlighting source satisfying the diagnostic requirements for dense plasma probing. High- quality plasma images are obtained with the backlighfing 4.7-keV X-rays in a Rayleigh-Taylor hydrodynamic instability experiment.展开更多
基金supported by the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2024ZD0302502 for WZ)the National Natural Science Foundation of China(Grant No.92365210 for WZ)+1 种基金Tsinghua Initiative Scientific Research Program (for WZ)the project of Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT,for YH)。
文摘To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.
基金supported by project of Beijing Postdoctoral Research Fund(Grant No.2025-ZZ-86)the National Natural Science Foundation of China(Grant Nos.12105020 and 12075031)+3 种基金Shenzhen Science and Technology Program(Grant No.KJZD20230923114219040)the Natural Science Youth Foundation of Henan Province,China(Grant No.242300420637)the Open Fund of Key Laboratory of Beam Technology of the Ministry of Education,Beijing Normal University(Grant No.BEAM2024G02)the Innovation Cultivation of Beijing Academy of Science and Technology(Grant Nos.25CB007-01 and 25CB007-02)。
文摘A double-parabola monocapillary(DPM)was designed for laboratory x-ray sources,and its performance was evaluated through numerical simulations and experimental validation.A surface shape error model was developed to characterize the DPM surface profile,and ray-tracing methods were used to simulate key properties such as focal spot size,divergence,and transmission efficiency.The simulation results closely matched experimental measurements,validating the proposed model.This surface shape error simulation provides an efficient method for evaluating the impact of slope errors on DPM performance,offering insights for optimal design and precision manufacturing.
基金funded by the National Natural Science Foundation of China(Grant No.42173054).
文摘Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were analyzed using gas chromatography(GC),gas chromatography-mass spectrometry(GC–MS),and gas chromatography-isotope ratio mass spectrometry(GC-IRMS).Theδ^(13)C values of forty-three LHs were recognized and determined by comparing the GC and GC-IRMS methods.The results revealed significant differences inδ^(13)C distribution characteristics among different LH compounds.Theδ^(13)C variation of individual LHs in iso-paraffins showed the widest range,followed by cycloalkanes and aromatics,whereas theδ^(13)C variation in n-paraffins showed the narrowest range.Theδ^(13)C values of most individual LHs are primarily affected by the source facies and thermal evolution.Among them,c-1,3-dimethylcyclohexane(c-1,3DMCH)is mainly sourced from higher plants but may also form through abiotic mechanisms such as catalysis or cyclization.Theδ^(13)C values of c-1,3DMCH(δ^(13)Cc-1,3DMCH)primarily exhibit parental genetic characteristics,enabling effective distinction of oil from different source facies.Specifically,theδ^(13)Cc-1,3DMCH in marine oils,lacustrine oils,terrigenous oils,and coal-formed oils are<–22‰,from–22‰to−20.2‰,from−20.2‰to−18.4‰,and>−18.4‰,respectively.Moreover,maturity is the primary controlling factor forδ^(13)C values of 3MC7(δ^(13)C3MC7,3MC7:3-methylheptane),while the source facies serve as a secondary influence.The plot ofδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 was introduced to classify source facies.Asδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 increase,the source facies transits from marine to lacustrine,then terrigenous,and finally coal facies.Additionally,increasingδ^(13)C3MC7 indicates a relative increase in maturity.Therefore,theδ^(13)Cc-1,3DMCH vs.δ^(13)C3MC7 plot serves as an effective tool for distinguishing source facies and assessing relative maturity.
基金supported by Natural Science Foundation of the Fujian Province,China(2024J010016)the National Key R&D Program of China(2021YFB3600400)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Project(2020ZZ113,2021ZZ130)。
文摘Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing the size of micro light sources and enhancing optical resolution,the efficient and simple fabrication of ultra-high-resolution micro light sources remains challenging due to its reliance on precise micro-nano processing technology and advanced processing equipment.In this study,a simple approach for the efficient fabrication of submicron light sources is proposed,namely shadow-assisted sidewall emission(SASE)technology.The SASE utilizes the widely adopted UV photolithography process,employing metal shadow modulation to precisely control the emission of light from polymer sidewalls,thereby obtaining photoluminescent light sources with submicron line widths.The SASE eliminates the need for complex and cumbersome manufacturing procedures.The effects of process parameters,including exposure dose,development time,and metal film thickness,on the linewidth of sources are investigated on detail.It is successfully demonstrated red,green,and blue submicron light sources.Finally,their potential application in the field of optical anti-counterfeiting is also demonstrated.We believe that the SASE proposed in this work provides a novel approach for the preparation and application of micro light sources.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301500)the National Natural Science Foundation of China(Grant No.62105366)。
文摘Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.
基金supported by Doctor's Scientific Research Initiation Project of Yan'an University(YAU202213093)National Nature Science Foundation of China(Grant No.41503029).
文摘As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.
基金supported by the Fundamental Research Funds for the Central Universities(WK2310000102)。
文摘Hefei Light Source(HLS)is a synchrotron radiation light source that primarily produces vacuum ultraviolet and soft X-rays.It currently consists of ten experimental stations,including a soft X-ray microscopy station.As part of its on-going efforts to establish a centralized scientific data management platform,HLS is in the process of developing a test sys-tem that covers the entire lifecycle of scientific data,including data generation,acquisition,processing,analysis,and de-struction.However,the instruments used in the soft X-ray microscopy experimental station rely on commercial propriet-ary software for data acquisition and processing.We developed a semi-automatic data acquisition program to facilitate the integration of soft X-ray microscopy stations into a centralized scientific data management platform.Additionally,we cre-ated an online data processing platform to assist users in analyzing their scientific data.The system we developed and de-ployed meets the design requirements,successfully integrating the soft X-ray microscopy station into the full lifecycle management of scientific data.
基金pported by the National Natural Science Foundation of China(Grant Nos.12325409,12388102,12074398,and U2267204)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-060)the Shanghai Pilot Program for Basic Research,Chinese Academy of Sciences Shanghai Branch。
文摘A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.
基金financial support by "the Fundamental Research Funds for the Central Universities"
文摘We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism colors were highly consistent of L＊D65∈（43.47, 46.75）, C＊D65∈（65.20, 68.80） and ho＊D65∈（138.10, 140.23）. We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the color of jadeite-jade green might be slightly influenced by alternating of the light sources.
文摘BACKGROUND Conventionally, the low luminous intensity, low image resolution, and difficulty in operation have been reported with the ultrathin endoscope. However, it has markedly advanced recently. The improvement of the diagnostic ability is expected.AIM To compare the early gastric cancer diagnostic ability of an ultrathin endoscope loaded with a laser light source and that of the conventional endoscope.METHODS The target subjects were 375 consecutive patients who underwent endoscopy at our hospital for post-endoscopic submucosal dissection follow-up of gastric cancer from January to August 2018. During endoscopy, the ultrathin endoscope was used in 140 patients(37.3%), and the conventional endoscope was used in235 patients(62.7%). Patient background was adjusted using the propensity score matching method, and gastric cancer detection ability was evaluated in the two groups.RESULTS The gastric cancer detection rate was 7.8% in the ultrathin endoscope group and7.0% in the conventional endoscope group, and the mean intragastric observation time was 4.1 ± 1.7 min in the ultrathin endoscope group and 4.1 ± 1.9 min in the conventional endoscope group, showing no significant differences between the groups. Moreover, the biopsy implementation rate was 31.8% in the ultrathin endoscope group and 41.1% in the conventional endoscope group, and the biopsy prediction rate was 17.9% and 13.2%, respectively, showing no significant differences between the groups.CONCLUSION The gastric cancer diagnostic ability of the ultrathin endoscope loaded with a laser light source was comparable to that of the conventional endoscope. The observation time was also comparable. Thus, endoscopy using the ultrathin endoscope loaded with the laser light source would be the first option in screening examinations of gastric cancer due to its low invasion.
文摘Distributed X-ray sources comprise a single vacuum chamber containing multiple X-ray sources that are triggered and emit X-rays at a specific time and location. This process facilitates an application for innovative system concepts in X-ray and computer tomography. This paper proposes a novel electron beam focusing, shaping,and deflection electron gun for distributed X-ray sources.The electron gun uses a dispenser cathode as an electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflection. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. Two identical half-rectangle opening electrodes are controlled by adjusting the potential of the two electrodes to control the electron beam trajectory, and then, multifocal spots are obtained on the anode target. The electron gun can increase the spatial density of the distributed X-ray sources, thereby improving the image quality. The beam experimental results show that the focal spot sizes of the deflected(deflected amplitude 10.5 mm)and non-deflected electron beams at full width at half maximum are 0.80 mm 90.50 mm and 0.55 mm 90.40 mm, respectively(anode voltage 160 kV; beam current 30 mA). The imaging experimental results demonstrate the excellent spatial resolution and time resolution of an imaging system built with the sources, which has an excellent imaging effect on a field-programmable gate array chip and a rotating metal disk.
基金supported by The National Key Research and Development Program of China(No.2017YFC0209500)the National Natural Science Foundation of China(Nos.91744204,41822703,and 91844301)National research program for key issues in air pollution control(No.DQGG-0103)。
文摘A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon(Br C),which has an important positive influence on radiative budget and climate change.In this work,we reported the absorption properties and potential source of Br C based on a seven-wavelength aethalometer in the winter of 2018–2019 at an urban site of Sanmenxia in Fenwei Plain in central China.Specifically,the mean value of Br C absorption coefficient was 59.6±36.0 Mm^(-1) at 370 nm and contributed 37.7%to total absorption,which made a significant impact on visibility and regional environment.Absorption coefficients of Br C showed double-peak pattern,and Br C had shown small fluctuations under haze days compared with clean days.As for the sources of Br C,Br C absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols,indicating that most of Br C originated from primary emissions.The linear correlations between trace metal elements(K,As,Fe,Mn,Zn,and Pb)and Br C absorption coefficients further referred that the major sources of Br C were primary emissions,like coal burning,biomass burning,and vehicle emissions.The moderate relationship between Br C absorption coefficients and secondary organic aerosols suggested that secondary production of Br C also played an important role.The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of Br C in and around this area,which inferred most parts of Br C were derived from local emissions.
文摘An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.
文摘A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were constructed based on images captured under four single light sources.Reconstruction image 1 was constructed by fusing greyscale versions of the original images into one image,and Reconstruction image2 was constructed based on the differences between the images captured under the different light sources.Subsequently,the four original images and two reconstructed images were input into the convolutional neural network AlexNet to recognize the density range in three cases:-1.5(clean coal) and+1.5 g/cm^(3)(non-clean coal);-1.8(non-gangue) and+1.8 g/cm^(3)(gangue);-1.5(clean coal),1.5-1.8(middlings),and+1.8 g/cm^(3)(gangue).The results show the following:(1) The reconstructed images,especially Reconstruction image 2,can effectively improve the recognition accuracy for the coal density range compared with images captured under single light source.(2) The recognition accuracies for gangue and non-gangue,clean coal and non-clean coal,and clean coal,middlings,and gangue reached88.44%,86.72% and 77.08%,respectively.(3) The recognition accuracy increases as the density moves further away from the boundary density.
文摘The different reflection characteristics of the surface of tin steel strips and the different speeds of the tinning line demand an adaptive illumination light source for online machine vision inspection. This light source can be integrated with a time delay integration charge-coupled device （TDI CCD ） to capture the images of moving objects and facilitate inspection of the surface quality of tin steel strips. On-site application show the effectiveness of the TDI camera with the adaptive illumination light source in detecting the surface defects on tin steel strips of three different materials and with different tin coating weights.
基金supported by the National Natural Science Foundation of China(No.62075019)the Science and Technology Development Program of Jilin Province(No.20190302124GX)the Science and Technology Innovation Fund of Changchun University of Science and Technology(No.XJJLG-2018-02).
文摘Aiming at the problem that the calibration results of the transmissometers cannot be traced to the meteorological optical range(MOR) defined by the World Meteorological Organization(WMO). We designed an indoor calibration light source of the transmissometers based on spatial light modulation, focusing on the design of a non-intersecting CzernyTurner spectroscopic system which achieved a spectral resolution of less than 1 nm in the range from 380 nm to 780 nm. Then, the calibration light source’s spectrum matching model is established and the digital micromirror device(DMD)’s surface illuminance distribution law is simulated and analyzed. Finally, the MOR error of the calibrated light source is inverted. The results show that the simulation spectrum error of the 2 700 K absolute color temperature is below ±7.4% in the wavelength range from 380 nm to 780 nm, and the MOR error meets the requirements of the International Civil Aviation Organization in 40-2 000 m of MOR.
基金supported by the Guangdong Basic and Application Basic Research Foundation of Guangdong Province (Nos. 2021A1515111149, 2021B1515120022, 2020B 010174003)。
文摘With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterilization characters of high power integrated light sources(ILSs) haven’t been widely investigated before utilizing in public sanitary security. In this work,by integrating up to 195 UVC-LED chips, high power UVC-LED ILSs with a light output power(LOP) of 1.88 W were demonstrated. The UVC-LED ILSs were verified to have efficient and rapid sterilization capability, which have achieved more than99.9% inactivation rate of several common pathogenic microorganisms within 1 s. In addition, the corresponding air sterilization module based on them was also demonstrated to kill more than 97% of Staphylococcus albus in the air of 20 m3 confined room within 30 min. This work demonstrates excellent sterilization ability of UVC-LED ILSs with high LOP, revealing great potential of UVC-LEDs in sterilization applications in the future.
基金the National Natural Science Foundation of China(No.U1564208).
文摘Energy optimization management can make fuel cell truck(FCT)power system more efficient,so as to improve vehicle fuel economy.When the structure of power source system and the torque distribution strategy are determined,the essence is to find the reasonable distribution of electric power between the fuel cell and other energy sources.The paper simulates the assistance of the intelligent transport system(ITS)and carries out the eco-velocity planning using the traffic signal light.On this basis,in order to further improve the energy efficiency of FCT,a model predictive control(MPC)-based energy source optimization management strategy is innovatively developed,which uses Dijkstra algorithm to achieve the minimization of equivalent hydrogen consumption.Under the scenarios of signalized intersections,based on the planned eco-velocity,the off-line simulation results show that the proposed MPC-based energy source management strategy(ESMS)can reduce hydrogen consumption of fuel cell up to 7%compared with the existing rule-based ESMS.Finally,the Hardware-in-the-Loop(HiL)simulation test is carried out to verify the effectiveness and real-time performance of the proposed MPC-based energy source optimization management strategy for the FCT based on eco-velocity planning with the assistance of traffic light information.
基金supported by the National High Technology Development Program of China (Grant No. 2009AA8046006)
文摘Several experiments are performed on the ShenGuang-Ⅱ laser facility to investigate an x-ray source and test radiography concepts. X-ray lines emitted from laser-produced plasmas are the most practical means of generating these high intensity sources. By using a time-integrated space-resolved keV spectroscope and pinhole camera, potential helium-like titanium Kα x-ray backlighting （radiography） line source is studied as a function of laser wavelength, ratio of pre-pulse intensity to main pulse intensity, and laser intensity （from 7.25 to ～ 11.3 × 10^15 W/cm2）. One-dimensional radiography using a grid consisting of 5 #m Au wires on 16 μm period and the pinhole-assisted point projection is tested. The measurements show that the size of the helium-like titanium Ka source from a simple foil target is larger than 100 ~m, and relative x-ray line emission conversion efficiency ~x from the incident laser light energy to helium- like titanium K-shell spectrum increases significantly with pre-pulse intensity increasing, increases rapidly with laser wavelength decreasing, and increases moderately with main laser intensity increasing. It is also found that a gold gird foils can reach an imaging resolution better than 5-μm featured with high contrast. It is further demonstrated that the pinhole-assisted point projection at such a level will be a novel two-dimensional imaging diagnostic technique for inertial confinement fusion experiments.
文摘An experiment with thin titanium foils irradiated by two pulses delayed in time is conducted on the bnenguang-Il laser facility. A prepulse induces an underdense plasma, 2-ns later a main pulse （λL ≈ 0.35 μm, EL ≈120 J, τL ≈100 ps） is injected into the underdense plasma and produces strong line emission from the titanium K shell （i.e., Hea at 4.7 keV）. Data show that the intensity of 4.7-keV X-ray emission with the prepulse is approximately twice more than without the prepulse, and can be used as a backlighting source satisfying the diagnostic requirements for dense plasma probing. High- quality plasma images are obtained with the backlighfing 4.7-keV X-rays in a Rayleigh-Taylor hydrodynamic instability experiment.
