Superconducting nanowire single-photon detectors （SNSPDs） with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and t...Superconducting nanowire single-photon detectors （SNSPDs） with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and the response bandwidth. Numerical simulation by the finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures at multiple frequency bands. The absorption capacity of the superconducting nanowires reaches 70%, 72%, 60.73%, 61.7%, 41.2%, and 46.5% at wavelengths of 684, 850, 732, 924, 1256, and 1426nm, respectively. The use of a composite optical structure reduces the total filling factor of superconducting nanowires to only 0.25, decreases the kinetic inductance of SNSPDs, and improves the count rates.展开更多
p-i-n Al_(x)Ga_(1−x)As/GaAs detectors with graded compositions and graded doping were grown and prepared.From the current-voltage and capacitance-voltage measurement results,the devices had good p-n junction diode cha...p-i-n Al_(x)Ga_(1−x)As/GaAs detectors with graded compositions and graded doping were grown and prepared.From the current-voltage and capacitance-voltage measurement results,the devices had good p-n junction diode characteristics,and the electric field strength under an unbiased voltage was 1.7×10^(5) Vcm^(-1).The full width at half maximum and charge collection efficiency of the detectors obtained from energy spectrum measurements of 5.48-MeV alpha particles were 3.04 and approximately 93%,respectively.In this study,we created the most advanced and promising state-of-the-art unbiased detector reported to date.展开更多
本文报道了小麦散装粮堆昆虫群落的组成和结构。利用粮虫陷井检测器检测,共获得432个检测样。据捕获储粮昆虫及螨类初步分类统计,当年入库小麦散装粮堆仓库昆虫计有13种,优势种群为玉米象,占捕获总虫量的87.5%,次要种类有麦蛾、书虱、...本文报道了小麦散装粮堆昆虫群落的组成和结构。利用粮虫陷井检测器检测,共获得432个检测样。据捕获储粮昆虫及螨类初步分类统计,当年入库小麦散装粮堆仓库昆虫计有13种,优势种群为玉米象,占捕获总虫量的87.5%,次要种类有麦蛾、书虱、腐嗜酪螨、麦蛾萝蜂。本文还报道了仓虫群落昼夜活动动态,垂直分布及种间相互关系。根据 Shannon—Wiener(1949)关于测量多样性及均匀度公式:多样性指数 H′=-sum from i=1 to S P_iI_nP_l,均匀度J′=H′/(I_nS)测量了仓虫均匀度 J′,多样性指数 H′。研究结果表明,小麦散装粮堆50—100厘米和100—150厘米粮堆区间,仓虫群落均匀度和多样性较高,说明小麦散装粮堆中部区域仓虫群落组成相对稳定。展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00100 and 2011CBA00200the National Natural Science Foundation of China under Grant Nos 11227904 and 61101012+1 种基金the National High-Technology ResearchDevelopment Program of China under Grant No 2011AA010204the Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves
文摘Superconducting nanowire single-photon detectors （SNSPDs） with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and the response bandwidth. Numerical simulation by the finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures at multiple frequency bands. The absorption capacity of the superconducting nanowires reaches 70%, 72%, 60.73%, 61.7%, 41.2%, and 46.5% at wavelengths of 684, 850, 732, 924, 1256, and 1426nm, respectively. The use of a composite optical structure reduces the total filling factor of superconducting nanowires to only 0.25, decreases the kinetic inductance of SNSPDs, and improves the count rates.
基金supported by the National Natural Science Foundation of China(No.61964001)General Project of Jiangxi Province Key R&D Program(No.20212BBG73012)+3 种基金Natural Science Foundation of Jiangxi Province(No.20192BAB207033)Key Scientific Research Projects of Henan Higher Education Institutions(No.22A490001)State Key Laboratory of Particle Detection and Electronics(No.SKLPDE-KF-2019)Jiangxi Provincial Postdoctoral Science Foundation(No.2019RC30).
文摘p-i-n Al_(x)Ga_(1−x)As/GaAs detectors with graded compositions and graded doping were grown and prepared.From the current-voltage and capacitance-voltage measurement results,the devices had good p-n junction diode characteristics,and the electric field strength under an unbiased voltage was 1.7×10^(5) Vcm^(-1).The full width at half maximum and charge collection efficiency of the detectors obtained from energy spectrum measurements of 5.48-MeV alpha particles were 3.04 and approximately 93%,respectively.In this study,we created the most advanced and promising state-of-the-art unbiased detector reported to date.
文摘本文报道了小麦散装粮堆昆虫群落的组成和结构。利用粮虫陷井检测器检测,共获得432个检测样。据捕获储粮昆虫及螨类初步分类统计,当年入库小麦散装粮堆仓库昆虫计有13种,优势种群为玉米象,占捕获总虫量的87.5%,次要种类有麦蛾、书虱、腐嗜酪螨、麦蛾萝蜂。本文还报道了仓虫群落昼夜活动动态,垂直分布及种间相互关系。根据 Shannon—Wiener(1949)关于测量多样性及均匀度公式:多样性指数 H′=-sum from i=1 to S P_iI_nP_l,均匀度J′=H′/(I_nS)测量了仓虫均匀度 J′,多样性指数 H′。研究结果表明,小麦散装粮堆50—100厘米和100—150厘米粮堆区间,仓虫群落均匀度和多样性较高,说明小麦散装粮堆中部区域仓虫群落组成相对稳定。
