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Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction

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Defence Technology（防务技术） 2024年第4期34卷 328-338页

作者： Yangtian Liu Xiaopeng Yan Qiang Liu Tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China china research and development academy of machinery equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference systems.However,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio fuzes.To solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is proposed.First,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)signal.Then,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for classification.The DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical algorithms.The trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

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research on the quasi-isentropic driving model of aluminized explosives in the detonation wave propagation direction

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Defence Technology（防务技术） 2024年第2期32卷 596-618页

作者： Hongfu Wang Yan Liu Fan Bai Chao He Yingliang Xu Qiang Zhou Chuan Xiao Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China china research and development academy of machinery equipment Beijing100089China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation direction.The research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was slowed down and even reversed to a slight rise

关键词： Aluminized explosive Flyer plate experiment Quasi-isentropic theoretical model Al reaction Driving characteristics

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High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence Technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu Junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China china research and development academy of machinery equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration.In the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s.Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered projectiles.By examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests.Furthermore,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism.Finally,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present study.Depending upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or hemispherical.Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model

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Command filtered integrated estimation guidance and control for strapdown missiles with circular field of view

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Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei Wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China china research and development academy of machinery equipment Beijing 100089China Northwest Industries Group CO. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： Integrated estimation guidance and control Circular field-of-view Time-varying integral barrier Lyapunov function Command filtered backstepping control Nonlinear adaptive control Extended state observer

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Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： Yang Yang Guanxin Yao china Institute for Agricultural equipment Industrial development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers respectively.The results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

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Design and optimization of fluid lubricated bearings operated with extreme working performances——a comprehensive review

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International Journal of Extreme Manufacturing 2024年第2期6卷 325-376页

作者： Guohua Zhang Ming Huang Gangli Chen Jiasheng Li Yang Liu Jianguo He Yueqing Zheng Siwei Tang Hailong Cui Institute of machinery Manufacturing Technology China Academy of Engineering PhysicsMianyangSichuan 621999People’s Republic of China

Fluid lubricated bearings have been widely adopted as support components for high-end equipment in metrology,semiconductor devices,aviation,strategic defense,ultraprecision manufacturing,medical treatment,and power generation.In all these applications,the equipment must deliver extreme working performances such as ultraprecise movement,ultrahigh rotation speed,ultraheavy bearing loads,ultrahigh environmental temperatures,strong radiation resistance,and high vacuum operation,which have challenged the design and optimization of reliable fluid lubricated bearings.Breakthrough of any related bottlenecks will promote the development course of high-end equipment.To promote the advancement of high-end equipment,this paper reviews the design and optimization of fluid lubricated bearings operated at typical extreme working performances,targeting the realization of extreme working performances,current challenges and solutions,underlying deficiencies,and promising developmental directions.This paper can guide the selection of suitable fluid lubricated bearings and optimize their structures to meet their required working performances.

关键词： fluid lubricated bearings structural design performance optimization extreme working performances

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Tourmaline guiding the electric field and dechlorination pathway of 2,3-dichlorophenol by Desulfitobacterium hafniense

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Journal of Environmental Sciences 2024年第1期135卷 262-273页

作者： Yue Lu Fangyi Liang Fanzhi Qin Linrui Zhong Jianhong Jiang Qi Liu Shoujuan Zhang Ming Yan Changzheng Fan Haoran Dong College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen research Institute Hunan UniverisyShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China china machinery International Engineering Design&research Institute Co. Ltd.Changsha 410007China Hunan Engineering research Center for Water Treatment Process&equipment Changsha 410007China

The dehalogenation of organohalides has been a research hotspot in bioremediation field;however,the influence of tourmaline,a natural ore that can generate spontaneous electric field,on organohalide-respiring bacteria(OHRB)and their dechlorination process is not well known.In this study,the effect and mechanism of tourmaline on the reductive dechlorination of 2,3-dichlorophenol(2,3-DCP)by Desulfitobacterium hafniense DCB-2Twere explored.The characterization results confirmed that tourmaline had good stability and the optimal dosage of tourmaline was 2.5 g/L,which shortened the total time required for dechlorination reaction to 72 hr.Besides,tourmaline amendment also increased the proportion of 2-chlorophenol(2-CP)from 18%to 30%of end products,while that of 3-CP decreased correspondingly.The theoretical calculations showed that the bond charge of the orthosubstituted chlorine declined from-0.179 to-0.067,and that of meta-substituted chlorine increased from-0.111 to-0.129,which indicated that the spontaneous electric field of tourmaline affected the charge distribution of 2,3-DCP and was more conducive to the generation of 2-CP.Overall,tourmaline with the spontaneous electric field affected the reductive dechlorination pathway of Desulfitobacterium,and the tourmaline-OHRB combining system might serve as a novel strategy for the bioremediation of environments polluted with chlorinated phenols.

关键词： Reductive dechlorination Desulfitobacterium hafniense Tourmaline Electric field 2 3-dichlorophenol

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Geobacter sulfurreducens promoted the biosynthesis of reduced graphene oxide and coupled it for nitrobenzene reduction

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Journal of Environmental Sciences 2024年第4期138卷 458-469页

作者： Shoujuan Zhang Qi Liu Linrui Zhong Jianhong Jiang Xiaozhe Luo Xingxin Hu Qian Liu Yue Lu College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen research Institute Hunan UniversityShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China china machinery International Engineering Design&research Institute Co. LtdChangsha 410007China Hunan Engineering research Center for Water Treatment Process&equipment Changsha 410007China

In order to explore an efficient and green method to deal with nitrobenzene(NB)pollutant,reduced graphene oxide(r GO)as an electron shuttle was applied to enhance the extracellular electron transfer(EET)process of Geobacter sulfurreducens,which was a typical electrochemically active bacteria(EAB).In this study,r GO biosynthesis was achieved via the reduction of graphene oxide(GO)by G.sulfurreducens PCA within 3 days.Also,the r GOPCA combining system completely reduced 50-200μmol/L of NB to aniline as end product within one day.SEM characterization revealed that PCA cells were partly wrapped by rGO,and therefore the distance of electron transfer between strain PCA and r GO material was reduced.Beside,the ID/IGof GO,r GO,and r GO-PCA combining system were 0.990,1.293 and 1.31,respectively.Moreover,highest currents were observed in r GO-PCA-NB as 12.950μA/-12.560μA at -408 m V/156 m V,attributing to the faster electron transfer efficiency in EET process.Therefore,the NB reduction was mainly due to:(I)direct EET process from G.sulfurreducens PCA to NB;(II)r GO served as electron shuttle and accelerated electron transfer to NB,which was the main degradation pathway.Overall,the biosynthesis of r GO via GO reduction by Geobacter promoted the NB removal process,which provided a facile strategy to alleviate the problematic nitroaromatic pollution in the environment.

关键词： Reduced graphene oxide Geobacter Nitrobenzene Removal Extracellular electron transfer

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Mechanism of high-energy pulsed current-assisted rolling of 08AL carbon steel ultra-thin strip

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Journal of Iron and Steel research(International) 2024年第2期31卷 416-427页

作者： Zhong-kai Ren Ya-nan Xu Jia-zhao Chen He Li Rui-lin Yuan Zhen-hua Wang Tao Wang Xiao Liu College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan030024ShanxiChina Engineering research Center of Advanced Metal Composites Forming Technology and equipment(Ministry of Education) Taiyuan University of TechnologyTaiyuan030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710016ShaanxiChina

To improve the plastic deformation performance of a 08AL carbon steel ultra-thin strip,a pulsed electric field was integrated into the plastic processing of the ultra-thin strip,and the effects of high-energy current on its deformation ability were investigated.Current-assisted tensile tests were employed,and the results clarified that the pulsed current could reduce the activation energy of faults and promoted dislocation slip within grains and at grain boundaries,leading to a decrease in the deformation resistance of the metal and an increase in its plastic properties.Under the current density of 2.0 A/mm2,the yield strength,tensile strength,and elongation of the rolled sample reached 425 MPa,467 MPa,and 12.5%,respectively.During the rolling process,it was found that the pulsed current promoted the dynamic recrystallization of the ultra-thin strip,reduced its dislocation density and deformation resistance,and promoted the coordinated deformation of the metal.

关键词： 08AL ultra-thin strip High-energy pulsed current Mechanical property Dislocation density Dynamic recrystallization

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Floating plants reduced methane fluxes from wetlands by creating a habitat conducive to methane oxidation

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Journal of Environmental Sciences 2024年第1期135卷 149-160页

作者： Fuwei Wang Songhe Zhang Xiuren Hu Xin Lv Min Liu Yu Ma Benjamin Manirakiza Key Laboratory of Integrated Regulation and Resource development on Shallow Lakes Ministry of EducationHohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 210098China china machinery International Engineering Desigh and research Institute co. Ltd.East China Regional CenterNanjing 210008China

Wetlands are one of the important natural sources of atmospheric methane (CH_4),as an important part of wetlands,floating plants can be expected to affect methane release.However,the effects of floating plants on methane release are limited.In this study,methane fluxes,physiochemical properties of the overlying water,methane oxidation potential and rhizospheric bacterial community were investigated in simulated wetlands with floating plants Eichhornia crassipes,Hydrocharis dubia,and Trapa natans.We found that E.crassipes,H.dubia,and T.natans plants could inhibit 84.31%-97.31%,4.98%-88.91%and 43.62%-92.51%of methane fluxes at interface of water-atmosphere compared to Control,respectively.Methane fluxes were negatively related to nutrients concentration in water column but positively related to the aerenchyma proportions of roots,stems,and leaves.At the same biomass,root of E.crassipes (36.44%) had the highest methane oxidation potential,followed by H.dubia (12.99%) and T.natans (11.23%).Forty-five bacterial phyla in total were identified on roots of three plants and 7 bacterial genera (2.10%-3.33%) were known methanotrophs.Type I methanotrophs accounted for 95.07%of total methanotrophs.The pmoA gene abundances ranged from 1.90×10^(16)to 2.30×10^(18)copies/g fresh weight of root biofilms.Abundances of pmoA gene was significantly positively correlated with environmental parameters.Methylotrophy (5.40%) and methanotrophy (3.75%) function were closely related to methane oxidation.This study highlights that floating plant restoration can purify water and promote carbon neutrality partially by reducing methane fluxes through methane oxidation in wetlands.

关键词： Floating plants Methane fluxes Aerenchyma Methanotrophs

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