During the storage of composite propellants, the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms...During the storage of composite propellants, the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms, aging processes, and safety performance. However, there is currently no non-destructive and quantitative detection method for migration of plasticizers in propellant liner. In this study, we developed a HTPB sensing liner by incorporating conductive fillers-namely carbon black(CB), carbon nanotubes(CNTs), and graphene nanoplatelets(GNP)-into the HTPB matrix. The synergistic interaction between CNTs and GNP facilitates the formation of a tunneling conductive network that imparts electrical conductivity to the HTPB liner. To elucidate the functional relationship between conductivity and nitroglycerin(NG) migration, we applied the HTPB sensing liner onto double base propellant surfaces and measured both the conductivity of the sensing layer and NG migration during a 71°C accelerated aging experiment. The results shows that when CNTs/GNP content reaches 3wt%, there is an exponential correlation between conductivity and NG migration with a fitting degree of 0.9652;the average response sensitivity of ΔR/R0 relative to NG migration is calculated as 41.69, with an average deviation of merely5.67% between NG migrations derived from conductivity fittings compared to those obtained via TGA testing results. Overall, this sensing liner exhibits excellent capabilities for detecting NG migration nondestructively and quantitatively while offering a novel approach for assessing interfacial component migrations as well as debonding defects in propellants-a promising avenue for future self-monitoring strategies regarding propellant integrity.展开更多
The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some w...The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some works can fool detectors by crafting the adversarial camouflage attached to the object,leading to wrong prediction.It is hard for military operations to utilize the existing adversarial camouflage due to its conspicuous appearance.Motivated by this,this paper proposes the Dual Attribute Adversarial Camouflage(DAAC)for evading the detection by both detectors and humans.Generating DAAC includes two steps:(1)Extracting features from a specific type of scene to generate individual soldier digital camouflage;(2)Attaching the adversarial patch with scene features constraint to the individual soldier digital camouflage to generate the adversarial attribute of DAAC.The visual effects of the individual soldier digital camouflage and the adversarial patch will be improved after integrating with the scene features.Experiment results show that objects camouflaged by DAAC are well integrated with background and achieve visual concealment while remaining effective in fooling object detectors,thus evading the detections by both detectors and humans in the digital domain.This work can serve as the reference for crafting the adversarial camouflage in the physical world.展开更多
Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy field. Based on the theory of the 3-D matched filtering an...Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy field. Based on the theory of the 3-D matched filtering and the optimal linear processing, the optimal point target detector is being analyzed in this paper. The performance of the detector is introduced in detail. The results provide a standard reference to evaluate the performance of any other point target detection algorithms.展开更多
为了满足乳制品中食源性致病菌精确、高效和高通量检测需求,文章以典型食源性致病菌大肠埃希氏菌O157、金黄色葡萄球菌、单核细胞增生李斯特氏菌和沙门氏菌作为目的菌,建立1种灵敏稳定的多重芯片式数字PCR(Multiplex digital chip PCR)...为了满足乳制品中食源性致病菌精确、高效和高通量检测需求,文章以典型食源性致病菌大肠埃希氏菌O157、金黄色葡萄球菌、单核细胞增生李斯特氏菌和沙门氏菌作为目的菌,建立1种灵敏稳定的多重芯片式数字PCR(Multiplex digital chip PCR)反应体系。针对4种致病菌的靶向基因,设计特异性引物,优化多重反应引物组合和反应条件,并验证其特异性和灵敏度。结果表明,该四重反应体系具有良好的特异性且未出现交叉反应。体系对4种菌株最低检出限分别达0.38、1.03、0.69 copies/μL和0.24 copies/μL,与单重反应体系检测灵敏度相当,未发生混合引物抑制反应。方法对模拟阳性样品、生乳和市售乳制品检测结果证明了其在乳原料及乳制品质量安全控制中的应用前景,文章构建的四重反应体系可为乳制品的检测与监管提供技术支持。展开更多
基于APD阵列的探测系统非常适合超高灵敏度、超高速探测,在主被动成像、激光雷达、医学检测、波前探测、光纤通信等领域应用广泛,时间数字转换器(Timeto Digital Converter,TDC)是其中的核心电路,完成对光子飞行时间(Time of Flight,ToF...基于APD阵列的探测系统非常适合超高灵敏度、超高速探测,在主被动成像、激光雷达、医学检测、波前探测、光纤通信等领域应用广泛,时间数字转换器(Timeto Digital Converter,TDC)是其中的核心电路,完成对光子飞行时间(Time of Flight,ToF)的高精度量化,对TDC电路的研究具有非常重要的军事和民用价值。本文首先介绍了TDC电路的原理与最简单的直接计数型结构,然后按三种典型结构分别综述了国内外适用于APD阵列的TDC电路的发展历程和最新成果,其中主要介绍了相位插值型TDC,最后比较了三种典型结构的特点,并总结了未来研究趋势。展开更多
基金funded by Zhijian Laboratory Open Fund,Rocket Force University of Engineering(Grant No.2023-ZJSYS-KF01-03).
文摘During the storage of composite propellants, the migration of plasticizers and other unbonded additives at the interfaces of liner adhesives has garnered significant attention in understanding liner failure mechanisms, aging processes, and safety performance. However, there is currently no non-destructive and quantitative detection method for migration of plasticizers in propellant liner. In this study, we developed a HTPB sensing liner by incorporating conductive fillers-namely carbon black(CB), carbon nanotubes(CNTs), and graphene nanoplatelets(GNP)-into the HTPB matrix. The synergistic interaction between CNTs and GNP facilitates the formation of a tunneling conductive network that imparts electrical conductivity to the HTPB liner. To elucidate the functional relationship between conductivity and nitroglycerin(NG) migration, we applied the HTPB sensing liner onto double base propellant surfaces and measured both the conductivity of the sensing layer and NG migration during a 71°C accelerated aging experiment. The results shows that when CNTs/GNP content reaches 3wt%, there is an exponential correlation between conductivity and NG migration with a fitting degree of 0.9652;the average response sensitivity of ΔR/R0 relative to NG migration is calculated as 41.69, with an average deviation of merely5.67% between NG migrations derived from conductivity fittings compared to those obtained via TGA testing results. Overall, this sensing liner exhibits excellent capabilities for detecting NG migration nondestructively and quantitatively while offering a novel approach for assessing interfacial component migrations as well as debonding defects in propellants-a promising avenue for future self-monitoring strategies regarding propellant integrity.
基金National Natural Science Foundation of China(grant number 61801512,grant number 62071484)Natural Science Foundation of Jiangsu Province(grant number BK20180080)to provide fund for conducting experiments。
文摘The object detectors can precisely detect the camouflaged object beyond human perception.The investigations reveal that the CNNs-based(Convolution Neural Networks)detectors are vulnerable to adversarial attacks.Some works can fool detectors by crafting the adversarial camouflage attached to the object,leading to wrong prediction.It is hard for military operations to utilize the existing adversarial camouflage due to its conspicuous appearance.Motivated by this,this paper proposes the Dual Attribute Adversarial Camouflage(DAAC)for evading the detection by both detectors and humans.Generating DAAC includes two steps:(1)Extracting features from a specific type of scene to generate individual soldier digital camouflage;(2)Attaching the adversarial patch with scene features constraint to the individual soldier digital camouflage to generate the adversarial attribute of DAAC.The visual effects of the individual soldier digital camouflage and the adversarial patch will be improved after integrating with the scene features.Experiment results show that objects camouflaged by DAAC are well integrated with background and achieve visual concealment while remaining effective in fooling object detectors,thus evading the detections by both detectors and humans in the digital domain.This work can serve as the reference for crafting the adversarial camouflage in the physical world.
文摘Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy field. Based on the theory of the 3-D matched filtering and the optimal linear processing, the optimal point target detector is being analyzed in this paper. The performance of the detector is introduced in detail. The results provide a standard reference to evaluate the performance of any other point target detection algorithms.
文摘基于APD阵列的探测系统非常适合超高灵敏度、超高速探测,在主被动成像、激光雷达、医学检测、波前探测、光纤通信等领域应用广泛,时间数字转换器(Timeto Digital Converter,TDC)是其中的核心电路,完成对光子飞行时间(Time of Flight,ToF)的高精度量化,对TDC电路的研究具有非常重要的军事和民用价值。本文首先介绍了TDC电路的原理与最简单的直接计数型结构,然后按三种典型结构分别综述了国内外适用于APD阵列的TDC电路的发展历程和最新成果,其中主要介绍了相位插值型TDC,最后比较了三种典型结构的特点,并总结了未来研究趋势。
