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Laser powder bed fusion of NiTiFe shape memory alloy via premixed powder:microstructural evolution,mechanical and functional properties

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Rare Metals 2024年第5期43卷 2300-2316页

作者： Bo Yuan Jin-Guo Ge Liang Zhang Hong-Jun Chen Long-Sha Wei Yu-Duo Zhou Run-Hua Song Institute of Intelligent Manufacturing technology Shenzhen PolytechnicShenzhen 518055China School of Mechanical and Electrical Engineering Guilin University of Electronic TechnologyGuilin 541004China Guangdong Advanced Polymer Composite Engineering technology research center Shenzhen Academy of Aerospace TechnologyShenzhen 518057China Jihua Laboratory Testing center Jihua LaboratoryFoshan 528000China

High-cost pre-alloyed powder is the bottleneck problem that limits the widespread application of additivemanufactured shape memory *** this work,the lowcost ternary NiTiFe shape memory alloy is fabricated by laser powder bed fusion(LPBF)technique via mechanically mixed pre-alloy NiTi powder and varying contents pure Fe powder(1,2,3 wt%).All NiTiFe alloys show a relative density of up to 99.8%by optimizing the LPBF processing *** to the heterogeneous nucleation effect of micron-sized Fe particles,both grain refinement and texture weakening are generated in the NiTiFe alloys,accompanied by the reduction of dislocation *** the room-temperature mechanical properties,the NiTi-3Fe alloy shows the highest microhardness of HV370,but the fracture strength and elongation reduce to1701 MPa and 23%*** evolution of mechanical properties is attributed to the high internal defects,low dislocation density and the incoherent ***,the NiTi-3Fe alloy shows the quasi-linear superelasticity behavior;the superelastic recoverable strain of NiTi-1Fe and NiTi-2Fe decreased with the increase in Fe *** study provided a new-fangled insight for the development of multi-component NiTi-based shape memory alloys by additive manufacturing.

关键词： Additive manufacturing Shape memory alloy Metal matrix composite Microstructure Mechanical properties

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Identification,characterization,and verification of miR399 target gene in grape

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Horticultural Plant Journal 2024年第1期10卷 91-102页

作者： Maosong Pei Hainan Liu Tonglu Wei Huiying Jin Yihe Yu Mengting Ma Xiaomeng Song Rundong Dai Dalong Guo Henan Engineering technology research center of Quality Regulation and Controlling of Horticultural Plants College of Horticulture and Plant ProtectionHenan University of Science and TechnologyLuoyangHenan 471023China

The microRNA miR399 plays an important role in phosphorus signal transduction pathways in ***,miR399 was shown to be closely associated with berry ripening in grape(Vitis vinifera).The objective of the present study was to elucidate the evolutionary characteristics of the miR399 gene family in grape and to verify the cleavage effect on the target *** miR399s were identified by miRNA sequencing and retrieval from the miRBase *** mature sequences and precursor sequences were subjected to phylogenetic analysis to reconstruct evolutionary trees,as well as secondary structure analysis of the precursor sequence,and prediction of target *** cisacting elements in the miR399 promoter were predicted and the cleavage effect of grape miR399b on its target genes was *** grape miR399 family comprised nine precursor sequences and nine mature *** precursor sequences formed a typical and stable stem—loop *** minimum folding free energy ranged from-55.70 kcal·mol^(-1)to-37.40 kcal·mol^(-1).Multiple sequence alignment revealed that the miR399 family was highly *** grape miR399 family was phylogenetically closely related to peach,apple,and citrus *** miR399s were predicted to target inorganic phosphate transporter 1—3,phospholipase D delta-like,and *** cleavage effect of grape miR399b on the target genes was verified by means of a dual-luciferase assay and 5’*** GUS staining showed that the promoter activity of miR399b was promoted by GA3treatment.

关键词： Grape miR399 Phosphorus metabolism Early ripening

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Flow characterization of macroporous W-4.8 vol.%ZrO2 alloy during hot deformation with improved constitutive equation and processing maps

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Tungsten 2024年第3期6卷 610-620页

作者： Jia-Hao Ye Liu-Jie Xu Ji-Kang Hu School of Materials Science and Engineering Henan University of Science and Technology National Joint Engineering research center for Abrasion Control and Molding of Metal Materials Henan University of Science and Technology

In this work,isothermal compression experiments of macroporous W-4.8 vol.%ZrO2（W-4.8ZrO2） at 1300-1600℃ and strain rate of 0.005-1 s-1were carried out on a Gleeble-1500D thermo-mechanical *** dynamic recovery of W-4.8ZrO2is the main "softening" *** the basis of Arrhenius model,the initial constitutive equation is established by exploring the influence of temperature,strain rate and rheological *** on Arrhenius model,the relationship between flow stress,strain rate and deformation temperature is *** the influence of strain,the improved constitutive equation and the law of material constant changing with the strain are *** that,the hot processing maps were drawn on the basis of the dynamic material model,which is used to analyze the instability mechanism of the W-4.8ZrO2,and determine the appropriate hot working process parameters(temperature:1350-1450℃,strain rate:0.1-1 s-1).

关键词： Tungsten alloy Flow characteristics Constitutive equation Hot processing maps

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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 *** 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

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

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A Framework Based on the DAO and NFT in Blockchain for Electronic Document Sharing

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2373-2395页

作者： Lin Chen Jiaming Zhu Yuting Xu Huanqin Zheng Shen Su Cyberspace Institute of Advanced technology Guangzhou UniversityGuangzhou510006China Engineering research center of lntegration and Application of Digital Learning technology Ministry of EducationBeijing100816China

In the information age,electronic documents(e-documents)have become a popular alternative to paper documents due to their lower costs,higher dissemination rates,and ease of knowledge ***,digital copyright infringements occur frequently due to the ease of copying,which not only infringes on the rights of creators but also weakens their creative ***,it is crucial to establish an e-document sharing system that enforces copyright ***,the existing centralized system has outstanding vulnerabilities,and the plagiarism detection algorithm used cannot fully detect the context,semantics,style,and other factors of the *** watermark technology is only used as a means of infringement *** paper proposes a decentralized framework for e-document sharing based on decentralized autonomous organization(DAO)and non-fungible token(NFT)in *** use of blockchain as a distributed credit base resolves the vulnerabilities inherent in traditional centralized *** e-document evaluation and plagiarism detection mechanisms based on the DAO model effectively address challenges in comprehensive text information checks,thereby promoting the enhancement of e-document *** mechanism for protecting and circulating e-document copyrights using NFT technology ensures effective safeguarding of users’e-document copyrights and facilitates e-document ***,recognizing the security issues within the DAO governance mechanism,we introduce an innovative optimization *** experimentation,we validate the enhanced security of the optimized governance mechanism,reducing manipulation risks by up to 51%.Additionally,by utilizing evolutionary game analysis to deduce the equilibrium strategies of the framework,we discovered that adjusting the reward and penalty parameters of the incentive mechanism motivates creators to generate superior quality and unique e-documents,while evaluators are more likely to engage in

关键词： Electronic document sharing blockchain DAO NFT evolutionary game

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Inhibition of protein degradation increases the Bt protein concentration in Bt cotton

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Journal of Integrative Agriculture 2024年第6期23卷 1897-1909页

作者： Yuting Liu Hanjia Li Yuan Chen Tambel Leila.I.M Zhenyu Liu Shujuan Wu Siqi Sun Xiang Zhang Dehua Chen Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation center for Modern Production technology of Grain Crops Yangzhou UniversityYangzhou 225009China Agricultural research Cooperation Biotechnology and Biosafety Research CenterKhartoum 13314Sudan

Bacillus thuringiensis(Bt)cotton production is challenged by two main problems,i.e.,the low concentration of Bt protein at the boll setting stage and the lowest insect resistance in bolls among all the cotton plant’s ***,increasing the Bt protein concentration at the boll stage,especially in bolls,has become the main goal for increasing insect resistance in *** this study,two protein degradation inhibitors(ethylene diamine tetra acetic acid(EDTA)and leupeptin)were sprayed on the bolls,subtending leaves,and whole cotton plants at the peak flowering stage of two Bt cultivars(medium maturation Sikang 1(SK1))and early maturation Zhongmian 425(ZM425)in 2019 and *** Bt protein content and protein degradation metabolism were *** results showed that the Bt protein concentrations were enhanced by 21.3 to 38.8%and 25.0 to 38.6%in the treated bolls of SK1 and ZM425 respectively,while they were decreased in the subtending leaves of these treated *** the treated leaves,the Bt protein concentrations increased by 7.6 to 23.5%and 11.2 to 14.9%in SK1 and ZM425,*** combined application of EDTA and leupeptin to the whole cotton plant increased the Bt protein concentrations in both bolls and subtending *** Bt protein concentrations in bolls were higher,increasing by 22.5 to 31.0%and 19.6 to 32.5%for SK1 and ZM425,*** organs treated with EDTA or/and leupeptin showed reduced free amino acid contents,protease and peptidase activities and significant enhancements in soluble protein *** results indicated that inhibiting protein degradation could improve the protein content,thus increasing the Bt protein concentrations in the bolls or/and leaves of cotton ***,the increase in the Bt protein concentration without yield reduction suggested that these two protein degradation inhibitors may be applicable for improving insect resistance in cotton production.

关键词： Bt cotton Bt protein inhibition of protein degradation protein degradation metabolism

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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 *** 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 *** 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/*** erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered *** 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 ***,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 ***,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 *** upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or *** 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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GOES-16 ABI Brightness Temperature Observations Capturing Vortex Rossby Wave Signals during Rapid Intensification of Hurricane Irma(2017)

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Journal of Meteorological research 2024年第4期38卷 768-783页

作者： Yanyang HU Xiaolei ZOU Joint center of Data Assimilation for research and Application Nanjing University of Information Science&TechnologyNanjing 210044

Geostationary Operational Environmental satellite-16(GOES-16) Advanced Baseline Imager(ABI) observations of brightness temperature(TB) are used to examine the temporal evolutions of convection-affected structures of Hurricane Irma(2017) during its rapid intensification(RI) period from 0600 to 1800 UTC 4 September *** ABI observations reveal that both an elliptical eye and a spiral rainband that originated from Irma's eyewall obviously exhibit wavenumber-2 TB *** elliptical eye underwent a counterclockwise rotation at a mean speed of a wavenumber-2 vortex Rossby edge wave from 0815 to 1005 UTC 4 *** the following about 2 hours(1025–1255 UTC 4 September),an inner spiral rainband originated from the eyewall and propagated at a phase speed that approximates the vortex Rossby wave(VRW) phase speed calculated from the aircraft reconnaissance *** the RI period of Irma,ABI TB observations show an on–off occurrence of low TB intrusions into the eye,accompanying a phase lock of eyewall TB asymmetries of wavenumbers 1 and 2 and an outward propagation of VRW-like inner spiral rainbands from the *** phase lock leads to an energy growth of Irma's eyewall *** the eye remained clear from 1415 to 1725 UTC 4 September,an inner spiral rainband that originated from a large convective area also had a VRW-like outward propagation,which is probably due to a vertical tilt of *** study suggests a potential link between convection sensitive GOES imager observations and hurricane dynamics.

关键词： Geostationary Operational Environmental satellite(GOES)imager brightness temperature(TB) hurricane vortex Rossby wave(VRW)

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Privacy-Preserving Federated Mobility Prediction with Compound Data and Model Perturbation Mechanism

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China Communications 2024年第3期21卷 160-173页

作者： Long Qingyue Wang Huandong Chen Huiming Jin Depeng Zhu Lin Yu Li Li Yong Beijing National research center for Information Science and technology(BNRist) Department of Electronic EngineeringTsinghua UniversityBeijing 100084China China Mobile research Beijing 100032China

Human mobility prediction is important for many ***,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important *** rising federated learning provides us with a promising solution to this problem,which enables mobile devices to collaboratively learn a shared prediction model while keeping all the training data on the device,decoupling the ability to do machine learning from the need to store the data in the ***,existing federated learningbased methods either do not provide privacy guarantees or have vulnerability in terms of privacy *** this paper,we combine the techniques of data perturbation and model perturbation mechanisms and propose a privacy-preserving mobility prediction algorithm,where we add noise to the transmitted model and the raw data collaboratively to protect user privacy and keep the mobility prediction *** experimental results show that our proposed method significantly outperforms the existing stateof-the-art mobility prediction method in terms of defensive performance against practical attacks while having comparable mobility prediction performance,demonstrating its effectiveness.

关键词： federated learning mobility prediction privacy

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Adaptive observer-based integral event-triggered antivibration control of a full aircraft active landing gear system with irregular runway excitations

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Science China(Information Sciences) 2024年第6期67卷 248-261页

作者： Wenxiao HU Chenglong DU Fanbiao LI Xinmin CHEN Chunhua YANG Weihua GUI School of Automation Central South University research center in System Engineering for Special Aircrafts Ningbo Institute of Materials Technology and EngineeringChinese Academy of Sciences

This study addresses the antivibration issue of a full aircraft active landing gear system(LGS)under landing impact and runway excitations via a novel adaptive observer-based integral event-triggered control method. First, a full aircraft active LGS comprising a front gear and two synchronized main left and right gears with active suspensions is established, where the information exchange among them is not implemented directly. Second, two adaptive observers are designed separately for the front and main LGSs to identify the varying damping parameters and estimate the system states simultaneously. Third, estimated states are transmitted to a shared network through a novel integral event-triggered mechanism(I-ETM);thus, the front and main LGSs are interconnected, and a networked control scheme for the aircraft LGS is constructed. Additionally, the integrated active control law is designed with the aid of the transmitted states of the front and main LGSs, enhancing the robustness against the pitch vibration of the ***, the L2-stability of the hybrid system is guaranteed to depress the vertical vibration effect of the landing impact and irregular runway excitations, thus improving passenger safety and comfort. Moreover,a codesign method is provided to obtain feasible solutions to the gain matrices of the observers and controllers simultaneously. Simulation and comparison results are presented to illustrate the effectiveness and superiority of the proposed control scheme in antivibration and saving communication resources.

关键词： aircraft active landing gear antivibration control integral event-triggered mechanism adaptive observer \({\cal L}_{2}\)-stability

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