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Modeling the effects of urbanization on grain production and consumption in China

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Journal of Integrative Agriculture 2017年第6期16卷 1393-1405页

作者： lu wen-cong Chen Ning-lu Qian wen-xin China Academy for Rural Development Zhejiang University Hangzhou 310058 P.R. China School of Management Zhejiang University Hangzhou 310058 P.R. China

The impact of rapid urbanization on food security of China has received considerable *** is not clear whether China can strike a balance between urbanization and food security,especially grain *** have been numerous studies examining the effects of urbanization on grain production or consumption,but few studies have yet analyzed grain *** on the Chinese World Agricultural Regional Market Equilibrium Model（CWARMEM）,this paper explores the impacts of urbanization on national and regional grain balances through different *** CWARMEM is a global partial equilibrium multimarket model which captures the differences between urban and rural residents as well as the effects of *** results show that urbanization has a small negative effect on maintaining grain *** of that,China is able to achieve the objective of grain security set by its ***,urbanization changes regional grain balances across China：The position of Northeast China and North China,as two dominant grain suppliers of China,will be weaken;Central China and East China will increase dependence on other grain suppliers;the grain surplus of Northwest China will increase ***,in terms of grain category,urbanization helps China achieve self-sufficiency in food grain（rice and wheat）,while expands deficit of feed grain（maize）.

关键词： urbanization grain self-sufficiency grain security

Theoretical Studies on N_2H+O Reaction

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Chemical Research in Chinese Universities 2008年第3期24卷 371-377页

作者： lu Ying-wen lu wen-cai SU Zhong-min Jinan Vocational College Jinan 250100 P. R. China State Key Laboratory of Theoretical and Computational Chemistry Jilin University Changchun 130023 P. R. China Institute of Functional Material Chemistry Northeast Normal University Changchun 130024 P. R. China

The N2H＋O potential energy profile was studied at the CCSD（T）/6-311G＋＋（df,p）//MP2/6-311G（d,p） level. Reactions associated with four intermediates（cis-HNNO, trans-HNNO, NNHO, and NNOH） were investigated. The results indicate that N2H＋O reaction toward H＋N2O is more favored than that toward N2＋OH, consistent with previous experimental studies. The pathways for the two reactions are found to go through cis-HNNO, transition state, and finally to the products. The N2H＋O→NH＋NO reaction was studied in detail. Product NO in such a reaction is likely to occur via cis-HNNO, followed by trans-HNNO, and finally dissociates into NH＋NO. These results suggest that N2H＋O→NH＋NO is an important channel in NO production.

关键词： N2H+O NH+NO Potential energy profile

Ultrafast magnetization enhancement and spin current injection in magnetic multilayers by exciting the nonmagnetic metal

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 158-168页

作者： wen-Tian lu Zhe Yuan Xiaohong Xu Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China

A systematic investigation of spin injection behavior in Au/FM(FM=Fe and Ni)multilayers is performed using the superdiffusive spin transport *** exciting the nonmagnetic layer,the laser-induced hot electrons may transfer spin angular momentum into the adjacent ferromagnetic(FM)metals resulting in ultrafast demagnetization or *** find that these experimental phenomena sensitively depend on the particular interface reflectivity of hot electrons and may reconcile the different observations in the *** by the ultrafast spin currents carried by the hot electrons,we propose the multilayer structures to generate highly spin-polarized currents for the development of future ultrafast spintronics *** spin polarization of the electric currents carried by the hot electrons can be significantly enhanced by the joint effects of bulk and interfacial spin ***,the intensity of the generated spin current can be optimized by varying the number of repeated stacking units and the thickness of each metallic layer.

关键词： spintronics ultrafast magnetodynamics spin polarization transport magnetic multilayer

Crisis of Transient Chaos

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Chinese Physics Letters 2002年第7期19卷 901-903页

作者： Wang wen-Xiu, lu Yun-Qing Department of Physics and Complexity Science Center Yangzhou University

A new kind of crisis, which is marked by a sudden change of a strange repeller, is observed in an electronic relaxation oscillator. Firstly, by its simplified piecewise linear model, we show analytically that a strange repeller appears after a hole-induced crisis, and that the fractal dimension of the strange repeller and the average lifetime of the iterations in the region occupied by the original attractor suddenly change at the critical parameter value when the repeller disappears. Our numerical investigation convinces us that the corresponding phenomenon can be found in the original electronic relaxation oscillator.

关键词： Fractal dimension

Quantum Chromodynamics Sum Rules for the 1^(-/+) Vector Odd-Glueball

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Chinese Physics Letters 1996年第5期13卷 340-342页

作者： lu wen-tao LIU Jue-ping Department of Physics Wuhan UniversityWuhan 430072

The transverse part of the two-point function of the 1^(-/+) vector gluonic current is calculated by including the perturbative contributions and the non-perturbative ones resulted from condensates of dimensions up to *** a usual"resonance plus continuum " model of the spectral function,the quantum chromodynamics sum rules for the 1^(-/+) vector odd-glueball are derived,and the 1^(-/+) mass of that glueball is determined to be 1.87 GeV.

关键词： dimensions function transverse

The recent progress of functionally graded CNT reinforced composites and structures

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Science China(Physics,Mechanics & Astronomy) 2020年第3期63卷 8-24页

作者： Kim Meow Liew Zhouzhou Pan lu-wen Zhang Department of Engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Architecture and Civil Engineering City University of Hong KongKowloon 999077China

In the last decade,the functionally graded carbon nanotube reinforced composites(FG-CNTRCs)have attracted considerable interest due to their excellent mechanical properties,and the structures made of FG-CNTRCs have found broad potential applications in aerospace,civil and ocean engineering,automotive industry,and smart *** we review the literature regarding the mechanical analysis of bulk CNTR nanocomposites and FG-CNTRC structures,aiming to provide a clear picture of the mechanical modeling and properties of FG-CNTRCs as well as their composite *** review is organized as follows:(1)a brief introduction to the functionally graded materials(FGM),CNTRCs and FG-CNTRCs;(2)a literature review of the mechanical modeling methodologies and properties of bulk CNTRCs;(3)a detailed discussion on the mechanical behaviors of FG-CNTRCs;and(4)conclusions together with a suggestion of future research trends.

关键词： functionally graded carbon nanotube reinforced composite modeling methodology mechanical properties beam plate shell

A new design of 3D-printed orthopedic bone plates with auxeticstructures to mitigate stress shielding and improve intra-operative bending

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Bio-Design and Manufacturing 2020年第2期3卷 98-108页

作者： Sanjairaj Vijayavenkataraman Akhil Gopinath wen F.lu Division of Engineering New York University Abu DhabiAbu DhabiUAE Department of Mechanical and Aerospace Engineering Tandon School of EngineeringNew York UniversityBrooklynNYUSA Department of Mechanical Engineering National University of Singapore(NUS)SingaporeSingapore

Orthopedic bone plates are most commonly used for bone fracture fixation for more than 100 *** bone plate design had evolved over time overcoming many challenges such as insufficient strength and excessive plate–bone contact affecting the blood ***,it is only made of two materials,either stainless steel(AISI 316L)or titanium(Ti–6Al–4V).There are two main limitations of metallic bone implants,namely stress shielding and the problem of malocclusion caused by the displacement of the fracture site during *** overcome the two problems,a new bone plate design with the incorporation of auxetic structures is proposed in this *** study aims to use auxetic structure section in the bone plate that would decrease the stiffness of the region,thereby mitigating the stress-shielding effect and at the same time act as a deformable section to enable intra-operative bending for effective alignment while having enough bending strength and *** different auxetic structures namely re-entrant honeycomb and missing rib structures were *** auxetic structure incorporated bone plates were designed,finite element analysis was done,fabricated using direct metal laser sintering technique,and *** results indicate that the re-entrant honeycomb structure incorporated bone plates serve as an effective bone design compared to the conventional bone plate design,in terms of stress shielding and intra-operative bending while offering similar mechanical and bending strength.

关键词： Bone plates Negative Poisson's ratio structures 3D printing Additive manufacturing Stress shielding

Changes in grain-size and sedimentation rate of the Neogene Red Clay deposits along the Chinese Loess Plateau and implications for the palaeowind system

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Science China Earth Sciences 2005年第9期48卷 1452-1462页

作者： wen Lingjuan lu Huayu QIANG Xiaoke State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China

The wind system responsible for transporting dust onto the Chinese Loess Plateau during the late Miocene and Pliocene is still unknown and recent investigations highlight many controversies. This report aims to investigate spatiotemporal changes in grain-size and sedi- mentation rate of the Neogene Red Clay deposits in north China and to explore palaeoclimatic changes during the late Miocene and Pliocene, in particular the palaeowind system that trans- ported dust. Samples were collected from eight Red Clay sections on the Loess Plateau. Meas- urement and analysis show that there is a clear southward decrease in the mean grain-size index and in the coarse particle fraction (>20 μm). At Jiaxian site on the northern Loess Plateau, the average mean grain-size is around 20 μm, while at Lantian site in the south, the mean is around 9 μm. The coarse particle fraction >20 μm makes up 24.4% and 5.6%, at the two sites respec- tively. This distinct diversity of grain-size in the aeolian Red Clay deposit between the north and south indicate that the palaeodust was transported mainly by northerly low-level winds. The grain-size variations in the Red Clay deposits can also be divided into three stages (the lower, the middle and the upper interval): grain-size of the lower stage is significantly coarser than that of the middle stage, but finer than that of the upper stage. As a consequence, the intensity of pa- laeowind and desiccation of the dust source region during the late Miocene and Pliocene can be divided into three stages: 6.2―5.4 Ma, 5.4―3.5 Ma and 3.5―2.6 Ma. Strength of the palaeowind during the middle stage (5.4―3.5 Ma) is weaker than that of the previous and subsequent stages and the intensity of palaeowind during the latest stage (3.5―2.6 Ma) is stronger than that of the early time (6.2―5.4 Ma). Variations in the sedimentation rate of the Red Clay deposit can also be divided into three stages: the earlier, the middle and the later interval. The sedimentation rate of

关键词： Red Clay deposit, grain size, atmospheric circulation, the late Miocene and the Pliocene, Chinese Loess Plateau.

Synchronization of networks with time-varying couplings

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Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 438-454页

作者： lu wen-lian CHEN Tian-ping School of Mathematical Sciences Fudan University Department of Computer Science The University of WarwickCoventry CV4 7AL UK School of Computer Science and School of Mathematical Sciences Fudan Unicersity

In this paper, we present a review of our recent works on complete synchro-nization analyses of networks of the coupled dynamical systems with time-varying cou-plings. The main approach is composed of algebraic graph theory and dynamic system method. More precisely, the Hajnal diameter of matrix sequence plays a key role in in-vestigating synchronization dynamics and the joint graph across time periods possessing spanning tree is a doorsill for time-varying topologies to reach synchronization. These techniques with proper modification count for diverse models of networks of the cou-pled systems, including discrete-time and continuous-time models, linear and nonlinear models, deterministic and stochastic time-variations. Alternatively, transverse stability analysis of general time-varying dynamic systems can be employed for synchronization study as a special case and proved to be equivalent to Hajnal diameter.

关键词： Synchronization coupled dynamical system network time-varying coupling