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Defence Technology（防务技术） 2024年第4期34卷 134-142页

作者： Peng Wang Wen Qian Ruolei Zhong Fangfang he Xin Li Jie Chen Li Meng Yinshuang Sun Guansong he Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China State Key Laboratory of Environment-friendly Energy Materials School of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China

The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricated to address the above *** coordination complexes which consist of natural polyphenol tannic acid(TA) and Fe~Ⅲ were chosen to construct the inner shell,while the graphene sheets were used to build the outer *** resulting CL-20/TA-Fe~Ⅲ/graphene composites exhibited simultaneously improved thermal stability and safety performance with only 1 wt% double-shell content,which should be ascribed to the intense physical encapsulation effect from inner shell combined with the desensitization effect of carbon nano-materials from outer *** phase transition(ε to γ) temperature increased from 173.70 ℃ of pure CL-20 to 191.87℃ of CL-20/TA-Fe~Ⅲ/graphene ***,the characteristic drop height(H_(50)) dramatically increased from 14.7 cm of pure CL-20 to112.8 cm of CL-20/TA-Fe~Ⅲ/graphene composites,indicating much superior safety performance after the construction of the double-shell *** general,this work has provided an effective and versatile strategy to conquer the thermal stability and safety issues of CL-20 and contributes to the future application of high energy density energetic materials.

关键词： CL-20 Double-shell structure Thermal stability Safety performance Tannic acid Graphene sheets

Density-based ship detection in SAR images:Extension to a self-similarity perspective

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Chinese Journal of Aeronautics 2024年第3期37卷 168-180页

作者： Xueqian WANG Gang LI Zhizhuo JIANG Yu LIU You he Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China

Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of SAR *** SAR ship detectors often independently handle small sub-images cropped from a large marine SAR image and do not exploit the nonlocal self-similarity *** this paper,we propose a new ship detector from the perspective of nonlocal self-similarity in SAR images to improve the ship detection performance,basically including three stages:prescreening,intra-cue calculation,and inter-cue *** the prescreening stage,we design a new Histogram-based Density(HD)feature to rapidly select candidate sub-images potentially containing ship targets from a large SAR *** the intra-cue calculation stage,target cues within a single candidate sub-image are *** the inter-cue calculation stage,thanks to the nonlocal self-similarity among different candidate sub-images in terms of density features,we innovatively extract a weighted superpixel-HD map to obtain accumulated intracues across all the candidate ***,for each candidate sub-image,we fuse its inter-cue and intra-cue to obtain final detection *** results based on real SAR images show that our newly proposed method provides a better target-to-clutter contrast and ship detection performance than those of other state-of-the-art detection approaches.

关键词： Ship detection Synthetic aperture radar(SAR) Density Self-similarity Histogram

Clifford Deformations of Koszul Frobenius Algebras and Noncommutative Quadrics

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Algebra Colloquium 2024年第1期31卷 63-82页

作者： Jiwei he Yu Ye Department of Mathematics Hangzhou Normal UniversityHangzhou 311121China School of Mathematical Sciences University of Science and Technology of China Hefei 230026China

A Clifford deformation of a Koszul Frobenius algebra E is a finite dimensional Z_(2)-graded algebra E(θ),which corresponds to a noncommutative quadric hypersurface E^(!)/(z)for some central regular element z∈E_(2)^(!).It turns out that the bounded derived category D^(b)(gr_(Z_(2))E(θ))is equivalent to the stable category of the maximal Cohen-Macaulay modules over E^(!)/(z)provided that E!is *** a consequence,E^(!)/(z)is a noncommutative isolated singularity if and only if the corresponding Clifford deformation E(θ)is a semisimple Z_(2)-graded *** preceding equivalence of triangulated categories also indicates that Clifford deformations of trivial extensions of a Koszul Frobenius algebra are related to Knörrer's periodicity theorem for quadric *** an application,we recover Knörrer's periodicity theorem without using matrix factorizations.

关键词： Koszul Frobenius algebra Clifford deformation noncommutative quadric hypersurface maximal Cohen-Macaulay module

Segregation of binary particles in gas-solid fluidized bed

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 113-121页

作者： Yaxiong Yu Feng Lu Xuan he Fei Wei Chenxi Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China Ordos Laboratory Ordos 017010China Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China

Particle segregation and mixing behavior play a crucial role in industrial *** study investigates the saturated jetsam fraction,which indicates the maximum capacity of flotsam to entrain jetsam,in an initially separated binary fluidized bed with particle size *** to the value of saturated jetsam fraction,three distinct regimes-segregation,mixing,and an intermediate regime-are ***,intriguing relationships between the saturated jetsam fraction and superficial gas velocity are observed,exhibiting monotonic trends in both the segregation and mixing regimes,while a unique volcano-shaped curve in the intermediate ***,a comprehensive entrainment model based on two-fluid model elucidates the observed phenomena,emphasizing the significance of mixing behavior in fluidized layer on the saturated jetsam *** work offers potential insights for evaluating segregation in industrial applications.

关键词： fluidized bed segregation binary bubbles entrainment

Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries

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Nano-Micro Letters 2024年第8期16卷 102-147页

作者： Fujuan Wang Tianyun Zhang Tian Zhang Tianqi he Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non‑Ferrous Metals Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion *** present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based *** review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation ***,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization ***,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

关键词： Cellulose Hard carbon Anode materials Rate performance Sodium-ion batteries

Construction of algal-bacterial consortia using green microalgae Chlorella vulgaris and As(Ⅲ)-oxidizing bacteria:As tolerance and metabolomic profiling

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Journal of Environmental Sciences 2024年第5期139卷 258-266页

作者： Xiaoman he Guobing Lin Jiayuan Zeng Zhaoguang Yang Lin Wang College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety Central South UniversityChangsha 410083China

Bioremediation became a promising technology to resolve arsenic(As)contamination in aquatic *** monoculture such as microalgae or bacteria was sensitive to environmental disturbance and vulnerable to contamination,green microalgae Chlorella vulgaris and arsenite(As(Ⅲ))-oxidizing bacteria Pseudomonas ***11 were co-cultured to construct algal-bacterial consortia in the current *** effects of algae-bacteria(A:B)ratio and exposure As(Ⅲ)concentration on algal growth,As speciation and metabolomic profile were *** growth arrested when treated with 100 mg/L As(Ⅲ)without the co-cultured *** contrast,co-cultured with strain SMS11 significantly enhanced As tolerance in *** especially with A:B ratio of 1:*** the As(Ⅲ)in culture media of the consortia were oxidized into As(Ⅴ)on day *** of As was observed on day *** 1% and 0.5% of total As were converted into dimethylarsinic acid(DMA)after 21days cultivation when the initial concentrations of As(Ⅲ)were 1 and 10 mg/L,*** analysis was further performed to reveal the response of consortia metabolites to external As(Ⅲ).The enriched metabolomic pathways were associated with carbohydrate,amino acid and energy *** acid cycle and glyoxylate and dicarboxylate metabolism were upregulated under As stress due to their biological functions on alleviating oxidative stress and protecting *** carbohydrate and amino acid metabolisms provided precursors and potential substrates for energy production and cell protection under abiotic *** of the pathways relevant to carbohydrate or amino acid metabolism were triggered by energy requirement.

关键词： Microalgae Algal-bacterial consortia As(Ⅲ)-oxidizing bacteria Metabolomics Energy metabolism

Characterization of Fe-containing particles in Chengdu,southwest China,using single-particle aerosol mass spectrometry

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Journal of Environmental Sciences 2024年第2期136卷 110-120页

作者： Renjiang he Junke Zhang Luyao Chen Wei Zhang Yingwei Xi School of Public health Southwest Medical UniversityLuzhou 646000China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Sichuan Environmental Monitoring Center Chengdu 610074China

Single-particle aerosol mass spectrometry was used to study the characteristics of Fecontaining particles during winter in Chengdu,southwest *** mass concentrations of PM_(2.5)and PM_(10)during the study period were 64±38 and 89±49μg/m~3,respectively,and NO_(2)and particulate matter were high compared with most other regions of *** Fecontaining particles were divided into seven categories with different mass spectra,sources and aging *** highest contribution was from Fe mixed with carbonaceous components(Fe-C,23.1%)*** was more mixed with sulfate than nitrate and therefore the contribution of Fe mixed with sulfate(Fe-S,20.7%)particles was higher than that of Fe mixed with nitrate(Fe-N,12.5%)*** contributions from Fe-containing particles related to primary combustion were high in the small particle size range,whereas aged Fecontaining particles and dust-related particles were mostly found in the coarse particle size *** air masses mainly originated from the west and east of Chengdu,and the corresponding PM_(2.5)concentrations were 79±36 and 55±36μg/m~3,*** west and east air masses showed stronger contributions of Fe-containing particles related to biomass burning(Fe-B)and fossil fuel combustion(Fe-C and Fe-S)particles,*** southwest area contributed the most Fe-containing *** assessments of the effects of Fe-containing particles during heavy pollution period should pay more attention to Fe-C and Fe-S ***-reduction of Fe-containing particles should consider both local emissions and short-distance transmission from the surrounding areas.

关键词： Fe-containing particles Particle composition Potential source areas Evolution Chengdu

Ca_(2)MnO_(4)-layered perovskite modified by NaNO_(3)for chemical-looping oxidative dehydrogenation of ethane to ethylene

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Chinese Journal of Chemical Engineering 2024年第4期68卷 53-64页

作者： Weixiao Ding Kun Zhao Shican Jiang Zhen Huang Fang he College of Chemistry and Bioengineering Guilin University of TechnologyGuilin 541006China Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox ***,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise *** modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) *** findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.

关键词： Chemical-looping oxidative dehydrogenation Ethane Ethylene NaNO_(3)-doped Ca_(2)MnO_(4)redox catalyst Layered perovskites

Longitudinal vibration characteristics of a tapered pipe pile considering the vertical support of surrounding soil and construction disturbance

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 51-63页

作者： Li Zhenya Pan Yunchao he Xianbin Lv Chong Mohammad Towhid Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China Geotechnical Research Institute Hohai UniversityNanjing 210098China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China

This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction ***,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile *** surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction ***,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost *** displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent ***,the displacement impedance at the pile head is obtained based on the impedance function transfer ***,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.

关键词： tapered pipe pile longitudinal vibration vertical support of the surrounding soil construction disturbance displacement impedance

Silicon photonic integrated interrogator for fiber-optic distributed acoustic sensing

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Photonics Research 2024年第3期12卷 465-473页

作者： ZHICheNG JIN JIAGENG CheN YANMING CHANG QINGWEN LIU ZUYUAN he State Key Laboratory of Advanced Optical Communication System and Networks Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Distributed acoustic sensing(DAS)technology has been a promising tool in various ***,the large size and relatively high cost of DAS equipment composed of discrete devices restrict its further popularization to some degree,and the photonic integration technology offers a potential *** this paper,we demonstrate an integrated interrogator for DAS on the silicon-on-insulator(SOI)*** design of the chip revolves around a Mach–Zehnder modulator(MZM)transmitter and a dual-quadrature and dualpolarization coherent *** integrated interrogator supports multiple DAS schemes,including the time-gated digital optical frequency domain reflectometry(TGD-OFDR),which is adopted for system performance evaluation.59■strain resolution in 12.1km sensing fiber with 1.14 m spatial resolution(SR)is ***,along 49.0 km sensing fiber,81■strain resolution with 3.78 m SR is *** results show that the integrated interrogator has comparable performance to the discrete DAS *** the best of our knowledge,this is the first dedicated on-chip DAS interrogator,which validates the effectiveness of the blend of photonics integration and DAS technology.

关键词： fiber polarization modulator