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基于联合置乱的高维超混沌图像加密算法

海军工程大学学报 2024年第5期36卷 74-79页

作者：陈云罗成许璐孟庆锐海军工程大学信息安全系武汉430033 91991部队浙江舟山316000

针对图像信息在传输过程中面临着被非法窃取、篡改等威胁的问题,提出了一种基于Arnold变换和DNA混合编码联合置乱的高维超混沌图像加密算法。首先,通过一种八维六次高维超混沌系统产生多个混沌伪随机系列,并经整数化处理,得到多个混沌... 详细信息

针对图像信息在传输过程中面临着被非法窃取、篡改等威胁的问题,提出了一种基于Arnold变换和DNA混合编码联合置乱的高维超混沌图像加密算法。首先,通过一种八维六次高维超混沌系统产生多个混沌伪随机系列,并经整数化处理,得到多个混沌伪随机整数系列和一个混沌矩阵;然后,采用这些混沌伪随机整数系列动态选取DNA混合编码规则和运算规则,对混沌矩阵和经Arnold变换后的原始图像矩阵进行DNA动态编码、运算和解码,从而实现图像加密;最后,将该算法应用于图像加密,通过计算机仿真进行了加密性能分析。结果表明:所提出的加密算法具有优异的性能,可为图像加密提供可行的选项。

关键词： Arnold变换 DNA混合编码超混沌图像加密

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九种常绿阔叶植物叶片解剖构造的研究

北方园艺 2024年第5期 53-61页

作者：孙国馨陈帆孟霄哲黄大庄孟庆瑞河北农业大学园林学院河北保定071066 保定市园林绿化中心河北保定070000

以9种常绿阔叶植物叶片为试材,采用人工低温处理测定其叶片相对含水量和相对电导率,并观测越冬前后叶片的微观解剖构造,通过变异系数、相关分析从8项叶片结构指标中筛选具有代表性的指标进行隶属函数分析和抗寒性综合评价,以期为北方树... 详细信息

以9种常绿阔叶植物叶片为试材,采用人工低温处理测定其叶片相对含水量和相对电导率,并观测越冬前后叶片的微观解剖构造,通过变异系数、相关分析从8项叶片结构指标中筛选具有代表性的指标进行隶属函数分析和抗寒性综合评价,以期为北方树种的选育提供参考依据。结果表明:在低温胁迫下,叶片的相对电导率整体表现为升高趋势、相对含水量整体表现为下降趋势。下表皮、栅栏组织较厚的叶片抗寒性较强,栅海比值和组织结构紧密度越大的植物受低温影响越小。越冬前后,阔叶植物的抗寒排序差异较大,较抗寒的树种有大叶女贞、红叶石楠、广玉兰等。

关键词：常绿阔叶植物低温胁迫叶片解剖构造抗寒性

Hydroelastic interaction between water waves and thin elastic plate floating on three-layer fluid

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Applied Mathematics and Mechanics(English Edition) 2017年第4期38卷 567-584页

作者： qingrui meng Dongqiang LU Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai UniversityShanghai 200072China

The wave-induced hydroelastic responses of a thin elastic plate floating on a three-layer fluid, under the assumption of linear potential flow, are investigated for two-dimensional cases. The effect of the lateral stretching or compressive stress is taken into account for plates of either semi-infinite or finite length. An explicit expression for the dispersion relation of the flexural-gravity wave in a three-layer fluid is analytically deduced. The equations for the velocity potential and the wave elevations are solved with the method of matched eigenfunction expansions. To simplify the calculation on the unknown expansion coefficients, a new inner product with orthogonality is proposed for the three-layer fluid, in which the vertical eigenfunctions in the open-water region are involved. The accuracy of the numerical results is checked with an energy conservation equation, representing the energy flux relation among three incident wave modes and the elastic plate. The effects of the lateral stresses on the hydroelastic responses are discussed in detail.

关键词： hydroelasticity lateral stress matched eigenfunction expansion orthogo- nality very large floating structure (VLFS)

Copper-based bimetallic electrocatalysts for CO_(2) reduction:From mechanism understandings to product regulations

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Materials Reports(Energy) 2023年第1期3卷 19-34,I0002页

作者： Haibei Yang Hongyuan Chuai qingrui meng Meiyan Wang Sheng Zhang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Haihe Laboratory of Sustainable Chemical TransformationsSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou350207China

Electrocatalytic carbon dioxide reduction reaction(CO_(2) RR)is a promising method to solve current environment and energy ***-based catalysts have been widely studied for converting CO_(2) into value-added hy-drocarbon *** monometallic catalyst has been proved to have some shortcomings,including relatively high energy barriers and diverse reaction pathways,leading to low reaction activities and poor product selec-tivity,*** copper-based bimetallic tandem catalysts have attracted extensive attentions due to their special catalyst structure,which can be easily regulated to achieve high CO_(2) RR reactivity and product *** the development of quantum chemistry calculations and spectroscopic characterization methods,deep understandings of CO_(2) RR from the mechanism perspective provide a broad horizon for the design of effi-cient *** review offers a good summary of reaction mechanisms and product regulation strategies over copper-based bimetallic catalysts,along with a brief discussion on future directions towards their practical applications.

关键词： Copper Bimetallic electrocatalysts Carbon dioxide reduction Mechanism Product regulations

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工作油温升对液粘传动调速起动的影响

农业机械学报 2010年第10期41卷 214-218,213页

作者：孟庆睿侯友夫中国矿业大学机电工程学院徐州221116

采用有限元法联立求解修正瞬态雷诺方程、热能量方程及润滑油粘温方程,对调速起动过程进行了数值模拟研究,讨论了起动过程中工作油温升对液粘传动调速起动的影响。结果表明,流入摩擦片工作油温度为30℃时,流经摩擦片后温度约升高20℃,... 详细信息

采用有限元法联立求解修正瞬态雷诺方程、热能量方程及润滑油粘温方程,对调速起动过程进行了数值模拟研究,讨论了起动过程中工作油温升对液粘传动调速起动的影响。结果表明,流入摩擦片工作油温度为30℃时,流经摩擦片后温度约升高20℃,它所引起的油膜承载力下降9%;而流入摩擦片工作油温度由30℃升至50℃时,即使不考虑流经摩擦片的温升,油膜承载力也将下降32%。这样易引起油膜承载力低于比例溢流阀死区对应压力,导致摩擦片直接接合,不能取得理想的调速起动效果。调速起动实验验证了理论分析的正确性。

关键词：液粘传动调速起动温升修正瞬态雷诺方程有限元法

Ultralow friction PTFE/PEEK heterolayer:A new solid lubrication approach toward simplicity

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Friction 2024年第1期12卷 120-135页

作者： Wei SUN Jiaxin YE qingrui SONG Yi FENG Xiaojun LIU School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Institute of Tribology School of Mechanical EngineeringHefei University of TechnologyHefei 230009China

Tribological applications of polytetrafluoroethylene(PTFE)are often limited by technological complexity to overcome its poor wear ***,a PTFE/polyetheretherketone(PEEK)heterolayer(HL)was proposed and evaluated as a new solid lubrication ***-on-disk tribometry found the lowest friction coefficient(μ)of 0.031 and ultralow wear for the PEEK/HL under typical *** friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%,and approaches that of highly lubricated *** investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface *** technological simplicity and robustness of the HL’s high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity.

关键词： ultralow friction anti-wear polytetrafluoroethylene(PTFE) heterolayer(HL)

Solid Bronsted acidity boosts adsorption reactivity of nano-adsorbent for water decontamination

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 23-34页

作者： Sikai Cheng Zhixian Li Kaisheng Zhang qingrui Zhang Xiaolin Zhang Bingcai Pan State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Environmental Materials and Pollution Control Laboratory Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Hebei Key Laboratory of Heavy Metal Deep-remediation in Water and Resource Reused Qinhuangdao 066004China Research Center for Environmental Nanotechnology(ReCENT) Nanjing UniversityNanjing 210023China

Despite the development of various Lewis acidic nano-adsorbents for fluoride removal through innersphere coordination,strong competition for hydroxyl ions still hinders efficient water *** addition,the critical issue of polysilicate scaling that results from the ubiquitous silicates must be *** tackle these issues,an alternative approach to enhancing adsorption reactivity by modifying nano-adsorbents with dual Lewis and Bronsted acidity is *** feasibility of this approach is demonstrated by growing zirconium phosphate(ZrP)inside a gel-type anion exchanger,N201,to produce nanocomposite ZrP@N201,in which the confined ZrP contained an otherwise metastable amorphous phase with Lewis acidic Zr^(4+) sites and Bronsted acidic monohydrogen phosphate groups(-O_(3)POH).Compared with the Lewis acidic nano-zirconium oxide analog(HZ0@N201),ZrP@N201 exhibited a greatly improved adsorption capacity(117.9 vs.52.3 mg/g-Zr)and mass transfer rate(3.56×10^(-6) vs.4.55×10^(-7) cm/s),while bulk ZrP produced a thermodynamically stableα-phase with Bronsted acidity that exhibited negligible adsorption capability toward *** enhanced defluoridation activity of ZrP@N201 is attributed to Bronsted acidity and the increased outer electron density of ZA+sites,as corroborated using XPS and solid-state NMR ***,Bronsted acidity strengthens the resistance of ZrP@N201 to silicate,allowing its full regeneration during cyclic *** tests demonstrated 3-10 times the amount of clean water from(waste)for ZrP@N201 as compared to both HZO@N201 and the widely used activated aluminum *** study highlights the potential of developing nano-adsorbents with dual acidities for various environmental remediation applications.

关键词： Nanocomposite Selective adsorption Fluoride removal Dual Lewis and Bronsted acidity Regeneration

Influencing Factors and Prediction of Risk of Returning to Ecological Poverty in Liupan Mountain Region,China

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Chinese Geographical Science 2024年第3期34卷 420-435页

作者： CUI Yunxia LIU Xiaopeng JIANG Chunmei TIAN Rujun NIU qingrui School of Geography and Planning Ningxia UniversityYinchuan 750021China Key Laboratory(China-Arab)of Resource Evaluation and Environmental Regulation of Arid Region in Ningxia Yinchuan 750021China

China has resolved its overall regional poverty in 2020 by attaining moderate societal *** country has entered a new development stage designed to achieve its second centenary ***,ecological fragility and risk susceptibility have increased the risk of returning to ecological *** this paper,the Liupan Mountain Region of China was used as a case study,and the counties were used as the scale to reveal the spatiotempora differentiation and influcing factors of the risk of returning to poverty in study *** indicator data for returning to ecological poverty from 2011-2020 were collected and summarized in three dimensions:ecological,economic and *** autoregressive integrated moving average model(ARIMA)time series and exponential smoothing method(ES)were used to predict the multidimensional indicators of returning to ecological poverty for 61 counties(districts)in the Liupan Mountain Region for *** back propagation neural network(BPNN)and geographic information system(GIS)were used to generate the spatial distribution and time variation for the index of the risk of returning to ecological poverty(RREP index).The results show that 1)ecological factors were the main factors in the risk of returning to ecological poverty in Liupan Mountain Region.2)The RREP index for the 61 counties(districts)exhibited a downward trend from *** RREP index declined more in medium-and high-risk areas than in low-risk *** 2021 to 2025,the RREP index exhibited a slight downward *** 2026 to2030,the RREP index was expected to decline faster,especially from 2029-2030.3)Based on the RREP index,it can be roughly divided into three types,namely,the high-risk areas,the medium-risk areas,and the low-risk *** natural resource conditions in lowrisk areas of returning to ecological poverty,were better than those in medium-and high-risk areas.

关键词： risk of returning to ecological poverty autoregressive integrated moving average model(ARIMA) exponential smoothing model back propagation neural network(BPNN) Liupan Mountain Region,China

Safe formation control of multiple unmanned aerial vehicles:control design and safety-stability analysis

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Control Theory and Technology 2024年第3期22卷 442-454页

作者： Haoqi Li Jiangping Hu qingrui Zhou Bijoy K.Ghosh School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313000ZhejiangChina Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094China Department of Mathematics and Statistics Texas Tech UniversityLubbockTX 79409-1042USA

Both safety and stability are primary performance criteria for multi-unmanned aerial vehicle(multi-UAV)systems in many coordination *** approaches often consider safety and stability *** is necessary and urgent to develop a safety-stability control strategy to merge these two performance *** this paper,a unified approach is developed to consider safety and stability for multi-UAV formation *** stability criterion is represented by a Lyapunov function and safety criterion is represented by a barrier function and then a relaxed converse control Lyapunov-barrier theorem is *** the help of a relaxed converse control Lyapunov-barrier function(RCCLBF),a distributed safety-stability formation control strategy is proposed for the multi-UAV *** transforming the solution of RCCLBF to a Lyapunovlike stabilization problem,we show that the proposed formation control strategy can drive the UAVs staying within a specified safe *** results are provided to validate the proposed safety-stability formation control strategy.

关键词： Multi-UAV system Formation control Lyapunov function Barrier function Stability with safety guarantee