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Nano-silica modified lightweight and high-toughness carbon fiber/phenolic ablator with excellent thermal insulation and ablation performance

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Defence technology（防务技术） 2024年第1期31卷 192-199页

作者： Wenjie Xu Wenda song Xianfeng jia cheng Ma jitong Wang Wenming Qiao Licheng Ling state Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China school of Chemical Engineering and Materials Changzhou Institute of TechnologyChangzhou 213032China Key Laboratory of specially Functional polymeric Materials and Related technology(Ministry of Education) School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

Lightweight and high-toughness carbon fiber/phenolic ablator(CFpA)is required as the thermal protection system(tps)material of aerospace vehicles for next-generation space *** improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(tMOs)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of *** modified CFpA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFpA from erosion of oxidizing atmosphere in different high-temperature *** oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFpA,which are 9.64%and 24.82%lower than the unmodified ***,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified ***,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified ***,the nano-silica modified CFpA with excellent overall performance presents promising prospects in high-temperature aerospace applications.

关键词： Nano-silica Carbonfiber phenolic aerogel Insulation Ablation

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searching for plant NLR immune receptors conferring resistance to potyviruses

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the Crop journal 2024年第1期12卷 28-44页

作者： Xin hong shufen Li Xiaofei cheng haijian Zhi jinlong yin Kai Xu jiangsu Key Laboratory for Microbes and Functional genomics Jiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing 210023JiangsuChina College of plant protection Northeast Agricultural UniversityHarbin 150030HeilongjiangChina National Center for soybean Improvement National Key Laboratory for Crop Genetics and Germplasm EnhancementKey Laboratory of Biology and Genetic Improvement of Soybean-Ministry of AgricultureNanjing Agricultural UniversityNanjing 210095JiangsuChina

to fight against invasion by pathogens,plants have evolved an elaborate innate immune system,of which the nucleotide-binding domain leucine-rich repeat-containing receptor(NLR)acts as the sensor and immune ***,comprising one of the largest genera of plant viruses,cause severe crop yield losses *** crop resistance to potyviruses can be used in breeding and plant transgenesis to control disease *** review summarizes achievements in mapping and cloning NLR genes conferring dominant resistance against potyvirus in the families Fabaceae,solanaceae,Brassicaceae,and *** compares mechanisms of potyviral protein recognition and downstream signaling employed by NLRs and discusses strategies for exploiting NLRs to better control diseases caused by potyviruses.

关键词： NLR potyvirus resistance genetic diversity Mapping Engineer

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state of the art in movement around a remote point:a review of remote center of motion in robotics

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Frontiers of Mechanical Engineering 2024年第2期19卷 1-28页

作者： Wuxiang ZhANg Zhi WANg Ke MA Fei LIU pengzhi cheng Xilun DINg school of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Ningbo Institute of technology Beihang UniversityNingbo 315832China Intelligent Aerospace Manufacturing Engineering technology Co. Ltd.Beijing 100191China

the concept of remote center of motion(RCM)is pivotal in a myriad of robotic applications,encompa-ssing areas such as medical robotics,orientation devices,and exoskeletal *** efficacy of RCM technology is a determining factor in the success of these robotic *** paper offers an exhaustive review of RCM technologies,elaborating on their various methodologies and practical *** delves into the unique characteristics of RCM across different degrees of freedom(DOFs),aiming to distill their fundamental *** addition,this paper categorizes RCM approaches into two primary classifications:design based and control *** are further organized according to their respective DOFs,providing a concise summary of their core *** upon the understanding of RCM’s versatile capabilities,this paper then transitions to an in-depth exploration of its applications across diverse robotic *** this review,we critically analyze the existing research challenges and issues that are inherently present in both RCM methodologies and their *** discussion is intended to serve as a guiding framework for future research endeavors and practical deployments in related areas.

关键词： remote center of motion mechanism robotics medical robot orientation device exoskeleton

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Acquiring Weak Annotations for tumor Localization in temporal and Volumetric Data

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Machine Intelligence Research 2024年第2期21卷 318-330页

作者： yu-cheng Chou Bowen Li Deng-ping Fan Alan yuille Zongwei Zhou Department of Computer science Johns Hopkins UniversityBaltimore 21218USA Computer Vision Lab ETH ZurichZurich 8001Switzerland

Creating large-scale and well-annotated datasets to train AI algorithms is crucial for automated tumor detection and ***,with limited resources,it is challenging to determine the best type of annotations when annotating massive amounts of unlabeled *** address this issue,we focus on polyps in colonoscopy videos and pancreatic tumors in abdominal Ct scans;Both applications require significant effort and time for pixel-wise annotation due to the high dimensional nature of the data,involving either temporary or spatial *** this paper,we develop a new annotation strategy,termed Drag&Drop,which simplifies the annotation process to drag and *** annotation strategy is more efficient,particularly for temporal and volumetric imaging,than other types of weak annotations,such as per-pixel,bounding boxes,scribbles,ellipses and ***,to exploit our Drag&Drop annotations,we develop a novel weakly supervised learning method based on the watershed *** results show that our method achieves better detection and localization performance than alternative weak annotations and,more importantly,achieves similar performance to that trained on detailed per-pixel ***,we find that,with limited resources,allocating weak annotations from a diverse patient population can foster models more robust to unseen images than allocating per-pixel annotations for a small set of *** summary,this research proposes an efficient annotation strategy for tumor detection and localization that is less accurate than per-pixel annotations but useful for creating large-scale datasets for screening tumors in various medical modalities.

关键词： Weak annotation detection localization segmentation colonoscopy abdomen

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A possible X-ray Quasi-periodic Oscillation in the Narrow-line seyfert 1 galaxy Mrk 142

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Research in Astronomy and Astrophysics 2024年第6期24卷 191-200页

作者： Xiao-gu Zhong jian-cheng Wang yong-yun Chen Xiao-Ling yu College of physics and Electronic Engineering Qujing Normal UniversityQujing 655011China yunnan Observatories Chinese Academy of SciencesKunming 650216China

A possible quasi-periodic oscillation(QpO) at frequency 7.045 × 10^(-5) hz is found in the narrow-line seyfert 1galaxy Mrk 142 in the data of XMM-Newton collected on 2020 April *** find that the QpO signal is statistically significantly larger than the 5σ level and highly coherent with quality factor Q > 5 at the 0.3–10 keV band by using the method of the Lomb–scargle periodogram,the Weighted Wavelet Z-transform and the *** analyze the data in 0.3–0.6 keV,0.6–1 keV,1–3 keV and 3–10 keV energy bands,and find obvious QpO signals at 0.3–0.6 keV and 1–3 keV *** then analyze the time-average spectra and time variability at the QpO frequency of 7.045 × 10^(-5) hz,and use a model to fit *** find that the QpO signal mainly comes from the X-ray hot corona.

关键词： X-rays:galaxies galaxies:seyfert accretion accretion disks radiation mechanisms:general

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Advanced preparation and application of bimetallic materials in lithium-sulfur batteries:A review

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journal of Energy Chemistry 2024年第1期88卷 469-512,I0011页

作者： yongbing jin Nanping Deng yanan Li hao Wang Meiling Zhang Weimin Kang Bowen cheng state Key Laboratory of separation Membranes and Membrane processes/National Center for International joint Research on separation Membranes School of Textile Science and EngineeringTiangong UniversityTianjin 300387China

Lithium-sulfur(Li-s)batteries are considered highly promising as next-generation energy storage systems due to high theoretical capacity(2600 Wh kg^(-1))and energy density(1675 mA h g^(-1))as well as the abundant natural reserves,low cost of elemental sulfur,and environmentally friendly ***,several challenges impede its commercialization including low conductivity of sulfur itself,the severe“shuttle effect”caused by lithium polysulfides(Lipss)during charge–discharge processes,volume expansion effects and sluggish reaction *** a solution,polar metal particles and their compounds have been introduced as the main hosts for sulfur cathode due to their robust catalytic activity and adsorption capability,effectively suppressing the“shuttle effect”of Li *** alloys and their compounds with multi-functional properties exhibit remarkable electrochemical performance more readily when compared to single-metal ***-designed bimetallic materials demonstrate larger specific surface areas and richer active sites,enabling simultaneous high adsorption capability and strong catalytic *** synergistic effect of the“adsorption-catalysis”sites accelerates the adsorptiondiffusion-conversion process of Li pss,ultimately achieving a long-lasting Li-s ***,the latest progress and performance of bimetallic materials in cathodes,separators,and interlayers of Li-s batteries are systematically ***,the principles and challenges of Li-s batteries are briefly ***,various mechanisms for suppressing“shuttle effects”of Li pss are emphasized at the ***,the performance parameters of various bimetallic materials are comprehensively summarized,and some improvement strategies are proposed based on these ***,the future prospects of bimetallic materials are discussed,with the hope of providing profound insights for the rational design and manufacturing of high-performance bimetallic materia

关键词： Bimetallic materials Lithium-sulfur batteries Effectively suppress shuttle effect of Lipss significantly improve reaction kinetics Exceptionally long lifespan

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Cavitation research with computational fluid dynamics:From Euler-Euler to Euler-Lagrange approach

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journal of hydrodynamics 2024年第1期36卷 1-23页

作者： Bin ji Zi-yang Wang huai-yu cheng Rickard E.Bensow state Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Department of Mechanics and Maritime sciences Chalmers University of TechnologyGothenburgSweden

Unsteady cavitating flow often contains vapor structures with a wide range of different length scales,from micro-bubbles to large cavities,which issues a big challenge to precisely investigate its evolution mechanism by computational fluid dynamics(CFD)*** present work reviews the development of simulation methods for cavitation,especially the emerging Euler-Lagrange ***,the progress of the numerical investigation of hot and vital issues is discussed,including cavitation inception,cloud cavitation inner structure and its formation mechanism,cavitation erosion,and cavitation *** is indicated that the Euler-Lagrange method can determine cavitation inception point *** cloud cavitation,the Euler-Lagrange method can reveal the source of microbubbles and their distribution law inside the shedding *** method also has advantages and great potential in assessing cloud cavitation-induced erosion and *** the ever-growing demands of cavitation simulation accuracy in basic research and engineering applications,how to improve the Euler-Lagrange method’s stability and applicability is still an open *** further promote the application of this advanced CFD simulation technology in cavitation research,some key issues are to be solved and feasible suggestions are put forward for further work.

关键词： numerical simulation Euler-Euler method Euler-Lagrange method bubble dynamicsgy,gothenburg,sweden

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In situ sulfur-doped mesoporous tungsten oxides for gas sensing toward benzene series

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Chinese Chemical Letters 2024年第7期35卷 502-507页

作者： yu Deng yan Liu yonghui Deng jinsheng cheng yidong Zou Wei Luo state Key Laboratory for Modification of Chemical Fibers and polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Department of Chemistry State Key Laboratory of Molecular Engineering of PolymersShanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsiChEMFudan UniversityShanghai 200433China Department of polymeric Materials School of Materials Science and EngineeringTongji UniversityShanghai 201804China henry-Fork school of Food sciences Shaoguan UniversityShaoguan 512005China state Key Lab of transducer technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

Benzene series as highly toxic gases have inevitably entered human life and produce great threat to human health and ecological environment,and thus it is distinctly meaningful to monitor benzene series with quickly,real-time and efficient ***,novel sulfur-doped mesoporous WO_(3)materials were synthesized via classical in-situ solvent evaporation induced co-assembly strategy combined with doping engineering,which possessed highly crystallized frameworks,high specific surface area(40.9–63.8 m^(2)/g)and uniform pore size(~18 nm).Benefitting from abundant oxygen vacancy and defects via s-doping,the tailored mesoporous s/m WO_(3)exhibited excellent benzene sensing performance,including high sensitivity(50 ppm vs.48),low detection limit(ca.500 ppb),outstanding selectivity and favorable *** addition,the reduction of band gap resulted from s-doping promotes the carrier migration in the sensing materials and the reaction at the gas–solid sensing *** provides brand-new approach to design sensitive materials with multiple reaction sites.

关键词： Mesoporous materials Benzene series tungsten oxides sulfur doping gas sensor

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time-dependent behavior and permeability evolution of limestone under hydro-mechanical coupling

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journal of Mountain science 2024年第5期21卷 1697-1714页

作者： WANg Zhilong ZENg Zhengqiang LyU cheng WANg Mingnian hU Xiongyu DONg yucang school of Civil Engineering Southwest Jiaotong UniversityChengdu 61003China College of Civil Engineering Tongji UniversityShanghai 200092China College of Water Resource and hydropower Sichuan UniversityChengdu 610065China hebei gEO University Shijiazhuang 050031China

Excessively high pore water pressure presents unpredictable risks to the safety of rock tunnels in mountainous regions that are predominantly composed of limestone. Investigating the creep characteristics and permeability evolution of limestone under varying hydrated conditions is crucial for a better understanding of the delayed deformation mechanisms of limestone rock tunnels. to this end, this paper initially conducts a series of multi-stage triaxial creep tests on limestone samples under varying pore water pressures. the experiment examines how pore water pressure affects limestone’s creep strain, strain rate, long-term strength, lifespan, and permeability, all within the context of hydraulicmechanical(hM) coupling. to better describe the creep behavior associated with pore water pressure, this paper proposes a new nonlinear fractional creep constitutive model. this constitutive model depicts the initial, steady-state, and accelerated phases of limestone’s creep behavior. Finally, the proposed model is applied to the numerical realization of deformation in limestone tunnel, validating the effectiveness of the proposed constitutive model in predicting tunnel’s creep deformation. this research enhances our understanding of limestone’s creep characteristics and permeability evolution under hM coupling, laying a foundation for assessing the longterm stability of mountain tunnels.

关键词： Creep test hydraulic-mechanical coupling Creep constitutive model Fractional derivatives pore pressure

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First identification of a novel Aichivirus D in goats with diarrhea

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journal of Integrative Agriculture 2024年第4期23卷 1442-1446页

作者： Chen yang Keha-mo Abi hua yue Falong yang cheng tang College of Animal&Veterinary sciences Southwest Minzu UniversityChengdu 610041China Key Laboratory of Qinghai-tibetan plateau Animal genetic Resource Reservation and Utilization Chengdu 610041China

Kobuvirus comprises 6 officially recognized species,namely Aichivirus A-F,and can be further divided into 20 genotypes through Vp1 gene phylogenetic analysis(https://***/report/chapter/picornaviridae/picornaviridae/kobuvirus).Aichivirus A in human,Aichivirus B in bovine,Aichivirus C in porcine and caprine,Aichivirus D in yak have been proved to be associated with diarrhea(Chen y s et al.2013;yang et al.2015;Zhu et al.2016;Zhai et al.2017;Wang et al.2020;Abi et al.2022;yan et al.2023).

关键词： corn diarrhea official

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