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Chinese Geographical science 2024年第1期34卷 149-167页

作者： LI Li LYU Xiao ZHANG Anlu NIU shandong PENG Wenlong School of Public Administration Huazhong Agricultural UniversityWuhan430070China Department of Geography University of ZurichZurich8057Switzerland School of Humanities and Law Northeastern UniversityShenyang110169China School of Geography and Tourism Qufu Normal UniversityRizhao276800China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural ***,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU *** address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating *** subsequently employed econometric models to analyze the significant factors that impact *** findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment ***,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in ***,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting ***,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for *** trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management ***,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters *** insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate *** conclusion,we propose research avenues for further enriching the SICLU framework to ensur

关键词： sustainable intensification of cultivated land use(SICLU) self-efficacy status quo bias input and output Boosted Regression Tree willingness to transfer cultivated land cultivated land planting areas shandong,China

Mechanical model of vulnerable atherosclerotic plaque rupture

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science China(Physics,Mechanics & Astronomy) 2004年第4期47卷 452-462页

作者： SU Haijun1, ZHANG Mei2.& ZHANG Yun2.1. School of Mathematics and System science, shandong {2., Jinan 2.0100, China 2. Qilu Hospital, shandong {2., Jinan 2.0012. China 1. School of Mathematics and System science Shandong University 250100 Jinan China 2. Qilu Hospital Shandong University 250012 Jinan China

Rupture of atherosclerotic plaque is the main trigger of acute cardiovascular events, but the mechanism of plaque rupture is still unknown. We have constructed a model describing the motion of the fibrous cap of the plaque using the theory of elastic mechanics and studied the stability of the plaque theoretically. It has shown that plaque rupture is the result of a dynamic interplay between factors intrinsic to the plaque itself and extrinsic factors. We have proposed a new mechanism of plaque rupture, given a new explanation about the nonlinear dynamic progress of atherosclerosis and suggested a method to identify the vulnerable plaques to manage atherosclerosis.

关键词： fibrous cap, parametric resonance, stability, mechanism, identification.

Development and evaluation of an online monitoring single-particle optical particle counter with polarization detection

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Journal of Environmental sciences 2024年第4期138卷 585-596页

作者： Weijie Yao Xiaole Pan Yu Tian Hang Liu Yuting Zhang shandong Lei Junbo Zhang Yinzhou Zhang LinWu Yele Sun Zifa Wang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

We developed a single-particle optical particle counter with polarization detection(SOPC)for the real-time measurement of the optical size and depolarization ratio(defined as the ratio of the vertical component to the parallel component of backward scattering)of atmospheric particles,the polarization ratio(DR)value can reflect the irregularity of the *** SOPC can detect aerosol particles with size larger than 500 nm and the maximum particle count rate reaches~1.8×10^(5)particles per *** SOPC uses a modulated polarization laser to measure the optical size of particles according to forward scattering signal and the DR value of the particles by backward S and P signal *** sampling rate of the SOPC was 106#/(sec·channel),and all the raw data were processed *** calibration curve was obtained by polystyrene latex spheres with sizes of 0.5-10μm,and the average relative deviation of measurement was 3.96% for sub 3μm particles.T-matrix method calculations showed that the DR value of backscatter light at 12.°could describe the variations in the aspect ratio of particles in the above size *** performed insitu observations for the evaluation of the SOPC,the mass concentration constructed by the SOPC showed good agreement with the PM_(2.5)measurements in a nearby state-controlled monitoring *** instrument could provide useful data for source appointment and regulations against air pollution.

关键词： Instrument development Single particle detection Measurement uncertainty Optical simulation Mass concentration

Prediction for RNA planar pseudoknots

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Progress in Natural science:Materials International 2007年第6期17卷 717-724页

作者： Li Hengwu1,2. Zhu Daming1, Liu Zhendong1 and Li Hong2.1. School of Computer science and Technology, shandong {2., Jinan 2.0100, China 2. Department of Computer, shandong Economic {2., Jinan 2.0014, China) [a]School of Computer science and Technology Shandong University Jinan China [b]Department of Computer Shandong Economic University Jinan China

Based on m-stems and semi-extensible structure, a model is presented to represent RNA planar pseudoknots, and corresponding dynamic programming algorithm is designed and implemented to predict arbitrary planar pseudoknots and simple non-planar pseudoknots with O(n4) time and O(n3) space. The algorithm folds total 2.5 sequences in the Pseudobase database, and the test results indicate that the algorithm has good accuracy, sensitivity and specificity.

关键词： algorithm RNA secondary structure pseudoknot dynamic programming.

Optimization of thermomechanical processes in Cu-Cr-Zr lead frame alloy using neural networks and genetic algorithms

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science China(Technological sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1,2. LIU Ping2. DONG Qiming2.& LI Hejun1 1. College of Materials science and Engineering, Northwestern Polytechnical university, Xi’an 710072. China 2. College of Materials science and Engineering, Henan university of science and Technology, Luoyang 471003, China 1. College of Materials science and Engineering Northwestern Polytechnical University 710072 Xi’an China 2. College of Materials science and Engineering Henan University of Science and Technology 471003 Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics

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science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2.1. Institute of Applied Mathematics, School of Math & System science, shandong {2., Jinan 2.0100, China 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science, Peking {2., Beijing 100871, China 1. Institute of Applied Mathematics School of Math & System Science Shandong University Jinan 250100 China 2. State Key Laboratory of Turbulence and Complex Systems & Department of Mechanics and Engineering science Peking University Beijing 100871 China

From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional operators,intermediate processes,critical phenomena,modern mechanics

Investigation on the Surface Coating of Grinding Balls

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Rare Metals 2001年第4期20卷 259-264页

作者： Chengguo Wang1 Yujun Bai1.2.1) College of Materials science and Engineering, shandong {2., Jinan 2.0061, China 2. Mechanical Department. shandong {2. of science and Technology. Jinan 2.003), China shandong Univ Coll Mat Sci & Engn Jinan 250061 Peoples R China Shanghai Univ Sci & Technol Dept Mech Jinan 250031 Peoples R China

The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of interface.

关键词： coating ball grinding plastic deformation

Stability for a class of nonlinear time-delay systems via Hamiltonian functional method

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science China(Information sciences) 2012年第5期55卷 1218-1228页

作者： YANG RenMing 1,2.& WANG YuZhen 1 1 School of Control science and Engineering,shandong {2.,Jinan 2.0061,China 2.shandong Jiaotong {2.,Jinan 2.002.,China 1. School of Control science and Engineering Shandong University Jinan 250061 China2. Shandong Jiaotong University Jinan 250023 China

This paper investigates the stability of a class of nonlinear time-delay systems via Hamiltonian functional method,and proposes a number of new results on generalized Hamiltonian realization (GHR) and stability analysis for this class of ***,the concept of GHR of general nonlinear time-delay systems is proposed,and several new GHR methods are ***,based on the new GHR methods obtained,the stability of time-delay systems is investigated,and several delay-dependent sufficient conditions in term of matrix inequalities are derived for the stability analysis by constructing suitable Lyapunov-Krasovskii (L-K) ***,an illustrative example shows that the results obtained in this paper have less conservatism,and work very well in the stability analysis of some nonlinear time-delay Hamiltonian systems.

关键词： nonlinear time-delay systems stability Hamiltonian functional method generalized Hamiltonian realization

Metal Transfer of Twin-wire Indirect Arc Argon Welding

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稀有金属材料与工程 2011年第S3期40卷 156-159页

作者： Cao Meiqing1, Zou Zengda2. Zhang Shunshan2. Qu Shiyao2.1shandong university of {2. and Technology, Qingdao 2.6510, China 2.0} university, Jinan 2.0061, China shandong Univ Sci & Technol Sch Mat Sci & Engn Qingdao 266510 Peoples R China shandong Univ Jinan 250061 Peoples R China

Metal transfer of twin-wire indirect arc argon welding was investigated with high speed camcorder system based on a xenon lamp source and digital oscillograph, forces on droplet were analyzed in this paper. Results show metal transfer mode that of anodal and cathodal is not completely the same. It was divided into seven types of transfer mode; spray transfer and spray-projected transfer are the important transfer mode. The base-plate was melted by energy that of the arc and drop carrying, the drop transfer direction is different from that of the current flow, anodal and cathodal drop transfer at the same time, only the frequence and size are different.

关键词： indirect arc metal transfer short circuiting transfer transfer mode