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Remote sensing image encryption algorithm utilizing 2D Logistic memristive hyperchaotic map and SHA-512

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Science China(Technological Sciences) 2024年第5期67卷 1553-1566页

作者： LAI Qiang liu yuan YAnG Liang School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang330013China

The two-dimensional Logistic memristive hyperchaotic map(2D-LMHM)and the secure hash SHA-512 are the foundations of the unique remote sensing image encryption algorithm(RS-IEA)suggested in this *** proposed map is formed from the improved Logistic map and the memristor,which has wide phase space and hyperchaotic range and is exceptionally excellent to be utilized in specific *** proposed image algorithm uses the permutation-assignment-diffusion *** generates two position matrices in a progressive manner to achieve an efficient random exchange of pixel positions,assignment is carried through on the image pixels of the permutated image to entirely remove the original image information,strengthening the relationship between permutation and diffusion,and loop diffusion in two different directions can use subtle changes of pixels to affect the whole *** random key and plain-image SHA-512 hash values are used to produce an additional key,which is then utilized to figure out the permutation parameters and the initial value of a chaotic *** experimental results with the average nPCR=99.6094%(nPCR:number of pixels change rate),average UACI=33.4638%(UACI:unified average changing intensity),100%pass rate of the targets in the test set,the average correlation coefficient is 0.00075,and the local information entropy is 7.9025,which shows that the algorithm is able to defend against a variety of illegal attacks and provide more trustworthy protection than some of the existing state-of-the-art algorithms.

关键词： chaos memristive hyperchaotic map remote sensing SHA-512 image encryption RS-IEA

Simultaneous measurement of distance and speed using frequency-modulated continuous-wave self-mixing interferometry and all-phase fast Fourier transform

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Chinese Optics Letters 2024年第7期22卷 29-34页

作者： Jinyuan yuan Bin liu School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China SECTE University of WollongongWollongong NSW 2522Australia

In this work,we propose a method using frequency-modulated continuous-wave(FMCw)self-mixing interferometry(SMI)and all-phase fast Fourier transform(APFFT)for simultaneous measurement of speed and *** offers superior accuracy in frequency determination by mitigating issues like the fence effect and spectrum leakage,contributing to the high-accuracy measurement for speed and *** simulations and experiments have demonstrated relative errors at the levels of 10^(−4) and 10^(−3) for distance and speed measurements,***,factors impacting measurement performance have been *** proposed method provides a high-performance and cost-effective solution for distance and speed measurements,applicable across scientific research and various industrial domains.

关键词： self-mixing interferometry frequency-modulated continuous-wave interferometry all-phase fast Fourier transform measurement of distance and speed.

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： yuan Zhang Xiang liu Chang-jun w.ng Chang liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the niAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(wC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of niAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Synergic action of linear dispersion, second-order nonlinearity, and third-order nonlinearity in shaping the spectral profile of a femtosecond pulse transporting in a lithium niobate crystal

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Photonics Research 2024年第4期12卷 774-783页

作者： LIHOnG HOnG yuanyuan liu ZHI-yuan LI State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

we present a detailed theoretical and numerical analysis on the temporal-spectral-spatial evolution of a highpeak-power femtosecond laser pulse in two sets of systems:a pure lithium niobate(Ln)plate and a periodically poled lithium niobate(PPLn)*** develop a modified unidimensional pulse propagation model that considers all the prominent linear and nonlinear processes and carried out the simulation process based on an improved split-step Fourier transformation *** theoretically analyze the synergic action of the linear dispersion effect,the second-order nonlinearity(2nd-nL)second-harmonic generation(SHG)effect,and the third-order nonlinearity(3rd-nL)self-phase modulation(SPM)effect,and clarify the physical mechanism underlying the peculiar and diverse spectral broadening patterns previously reported in Ln and PPLn thin plate *** analysis and discussion provides a deeper insight into the synergetic contribution of these linear and nonlinear effects brought about by the interaction of a femtosecond laser pulse with the Ln nonlinear crystal and helps to draw a picture to fully understand these fruitful optical physical processes,phenomena,and laws.

关键词： pulse nonlinearity lithium

Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang Rong liu Jing-yuan liu w.n-wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

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nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming Xia Yong-Jun Ye Shu-yuan liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for national Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allow.ng radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation numerical simulation Accumulation chamber

wearable Leg Movement Monitoring System for High-Precision Real-Time Metabolic Energy Estimation and Motion Recognition

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Research 2024年第2期2023卷 417-429页

作者： Jinfeng yuan Yuzhong Zhang Shiqiang liu Rong Zhu State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Comprehensive and quantitative assessment of human physical activity in daily life is valuable for healthcare,especially for those who suffer from obesity and neurological disorders or are at high risk of *** wearable devices,e.g.,smartwatches,are insufficient and inaccurate for monitoring highly dynamic limb movements and assessing human ***,we report a new wearable leg movement monitoring system incorporating a custom-made motion sensor with machine learning algorithm to perceive human motion accurately and comprehensively during diverse walking and running *** system enables real-time multimodal perceptions of personal identity,motion state,locomotion speed,and energy expenditure for wearers.A general law of extracting real-time metabolic energy from leg movements is verified although individual gaits show *** addition,we propose a novel sensing configuration combining unilateral lower leg movement velocity with its angular rate to achieve high accuracy and good generalizability while simplifying the wearable *** performances in personal identification(accuracy of 98.7%)and motion-state recognition(accuracy of 93.7%)are *** wearable system also exhibites high-precision real-time estimations of locomotion speed(error of 3.04%to 9.68%)and metabolic energy(error of 4.18%to 14.71%)for new subjects across various time-varying *** wearable system allows reliable leg movement monitoring and quantitative assessment of bodily kinematic and kinetic behaviors during daily activities,as well as safe identity authentication by gait parameters,which would greatly facilitate smart life,personal healthcare,and rehabilitation training.

关键词： smart enable monitoring

Multi-Perspective Data Fusion Framework Based on Hierarchical BERT: Provide Visual Predictions of Business Processes

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Computers, Materials & Continua 2024年第1期78卷 1227-1252页

作者： Yongw.ng yuan Xiangwei liu Ke Lu School of Mathematics and Big Data Anhui University of Science and TechnologyHuainan232001China School of Economics and Management Anhui University of Science and TechnologyHuainan232001China The Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji UniversityShanghai201804China

Predictive Business Process Monitoring(PBPM)is a significant research area in Business Process Management(BPM)aimed at accurately forecasting future behavioral *** present,deep learning methods are widely cited in PBPM research,but no method has been effective in fusing data information into the control flow for multi-perspective process ***,this paper proposes a process prediction method based on the hierarchical BERT and multi-perspective data ***,the first layer BERT network learns the correlations between different category attribute ***,the attribute data is integrated into a weighted event-level feature vector and input into the second layer BERT network to learn the impact and priority relationship of each event on future predicted ***,the multi-head attention mechanism within the framework is visualized for analysis,helping to understand the decision-making logic of the framework and providing visual ***,experimental results show that the predictive accuracy of the framework surpasses the current state-of-the-art research methods and significantly enhances the predictive performance of BPM.

关键词： Business process prediction monitoring deep learning attention mechanism BERT multi-perspective

Effect of surfactant frequently used in soil flushing on oxygen mass transfer in micro-nano-bubble aeration system

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Chinese Journal of Chemical Engineering 2024年第3期67卷 174-181页

作者： Mei Bai Zhibin liu Zhu liu Chenfei He Zhanhuang Fan Miaoxin yuan Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety Southeast UniversityNanjing 211189China CECEP DADI(Hangzhou)Environmental Remediation Co. Ltd.Hangzhou 310020China

In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated *** surfactant present in flushing solutions is bound to affect the aeration *** purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MnB)aeration ***,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MnB aeration ***,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MnB *** results showed that,for the tw.nty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)*** phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant *** addition,with the presence of electric charge,MnBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant ***,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MnB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant ***,the modified Frossling's model predicted the effect of surfactant on kL in MnB aeration system with reasonable accuracy.

关键词： Soil flushing Micro-nano-bubble aeration Bio-surfactant Mass transfer coefficient