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Multiplicity of Homoclinic Solutions for Second Order Hamiltonian Systems with Local Conditions at the Origin

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Acta Mathematica Sinica,English Series 2022年第4期38卷 735-744页

作者： peng LIU Fei guo School of Mathematics Tianjin UniversityTianjin 300354P.R.China Tianjin Key Laboratory of Brain-Inspired Intelligence Technology Tianjin 300354P.R.China

In this paper,the multiplicity of homoclinic solutions for second order non-autonomous Hamiltonian systemsü(t)-L(t)u(t)+▽uW(t,u(t))=0 is obtained via a new Symmetric Mountain Pass Lemma established by Kajikiya,where L∈C(R,RN×N)is symmetric but non-periodic,W∈C1(R×RN,R)is locally even in u and only satisfies some growth conditions near u=0,which improves some previous results.

关键词： Second order non-autonomous Hamiltonian systems Homoclinic solutions multiplicity new symmetric mountain pass lemma

Nijenhuis algebras, NS algebras, and N-dendriform algebras

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Frontiers of Mathematics in China 2012年第5期7卷 827-846页

作者： peng LEI Li guo Department of Mathematics Lanzhou University Lanzhou 730000 China Department of Mathematics and Computer Science Rutgers UniversityNewark NJ 07102 USA

In this paper, we study （associative） Nijenhuis algebras, with emphasis on the relationship between the category of Nijenhuis algebras and the categories of NS algebras and related algebras. This is in analogy to the well-known theory of the adjoint functor from the category of Lie algebras to that of associative algebras, and the more recent results on the adjoint functor from the categories of dendriform and tridendriform algebras to that of Rota- Baxter algebras. We first give an explicit construction of free Nijenhuis algebras and then apply it to obtain the universal enveloping Nijenhuis algebra of an NS algebra. We further apply the construction to determine the binary quadratic nonsymmetric algebra, called the N-dendriform algebra, that is compatible with the Nijenhuis algebra. As it turns out, the N-dendriform algebra has more relations than the NS algebra.

关键词： Nijenhuis algebras Rota-Baxter algebras dendriform algebras NSalgebras N-dendriform algebras

Theoretical Studies on the Interactions of Cations with Diazine

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1321-1330页

作者： CHEN xing WU Wen-peng ZHANG Jing-Lai CAO Ze-xing Institute of Fine Chemistry and Engineering Henan University Kaifeng 475001 China Department of Chemistry and State Key Laboratory for Physical Chemist~ of Solid Surfaces College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China

Density functional theory and MP2 calculations have been used to determine the geometries, stabilities, binding energies, and dissociative properties of cation-diazine complexes M^n＋-C4H4N2 （M^n＋= Li^＋, B^＋, Al^＋, Be^2＋, Mg^2＋, Ca^2＋）. The calculated results indicate that most complexes are stable except the π complexes of Ca^2＋-pyridazine, Ca^2＋-pyrazine, Al^＋-pyrimidine and Al^＋-pyrimidine. The a complexes are generally much more stable than their π counterparts. Among the π complexes, the cation-pyrazine π complexes have slightly higher stability. The nature of the ion-molecule interactions has been discussed by the natural bond orbital analysis and frontier molecular orbital interactions. In these a complexes, there is stronger covalent interaction between B^＋ and diazine. In the selected π complexes, B^＋ and Be^2＋ have stronger covalent interaction with diazine, while the other cations mainly have electrostatic interaction with diazine.

关键词： DFT and MP2 calculations cation-diazine complexes cation-molecule interactions

Multiplicity of Periodic Solutions for Second Order Hamiltonian Systems with Asymptotically Quadratic Conditions

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Acta Mathematica Sinica,English Series 2020年第1期36卷 55-65页

作者： peng LIU Fei guo School of Mathematics Tianjin University

A class of second order non-autonomous Hamiltonian systems with asymptotically quadratic conditions is considered in this *** Fountain Theorem,one multiplicity result of periodic solutions is obtained,which improves s... 详细信息

关键词： Second order Hamiltonian systems asymptotically quadratic conditions Fountain Theorem periodic solution multiplicity

Nucleation mechanisms of dynamic recrystallization in Inconel 625 superalloy deformed with different strain rates

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Rare Metals 2012年第3期31卷 215-220页

作者： guo, Qingmiao Li, Defu peng, Haijian guo, Shengli Hu, Jie Du, peng Nonferrous Metals Processing Division General Research Institute for Nonferrous Metals Beijing 100088 China

The effects of strain rates on the hot working characteristics and nucleation mechanisms of dynamic recrystallization (DRX) were studied by optical microscopy and electron backscatter diffraction (EBSD) technique. Hot compression tests were conducted using a Gleeble-1500 simulator at a true strain of 0.7 in the temperature range of 1000 to 1150 °C and strain rate range of 0.01 to 10.00 s?1. It is found that the size and volume fraction of the DRX grains in hot-deformed Inconel 625 superalloy firstly decrease and then increase with increasing strain rate. Meanwhile, the nucleation mechanism of DRX is closely related to the deformation strain rate due to the deformation thermal effect. The discontinuous DRX (DDRX) with bulging of original grain boundaries is the primary nucleation mechanism of DRX, while the continuous DRX (CDRX) with progressive subgrain rotation acts as a secondary nucleation mechanism. The twinning formation can activate the nucleation of DRX. The effects of bulging of original grain boundaries and twinning formation are firstly gradually weakened and then strengthened with the increasing strain rate due to the deformation thermal effect. On the contrary, the effect of subgrain rotation is firstly gradually strengthened and then weakened with the increasing strain rate.

关键词： nucleation mechanisms dynamic recrystallization Inconel 625 superalloy deformation strain rate

Nuclear alternating parity bands and transition rates in a model of coherent quadrupole–octupole motion in neutron-rich barium isotopes

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Nuclear Science and Techniques 2016年第6期27卷 150-154页

作者： xing Zhang Yong peng Chao-Biao Zhou Jia-xing Li School of Physical Science and Technology Southwest UniversityChongqing 400715China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

Deformed even–even nuclei Barium isotopes with quadrupole–octupole deformations are investigated on the basis of a collective *** model describes energy levels of the yrast band with alternating parity in the neutron-rich^(140;142;144;146;148)*** structure of the alternating parity bands is examined by odd–even (△I=1) staggering *** analytical method of the collective model is proposed for the calculation of E2 transition probabilities in alternating spectra of the nuclei^(140;142;144;146)Ba.

关键词：运动模型钡同位素丰中子同位素四极奇偶校验带相干 E2跃迁几率

Distribution prediction of moisture content of dead fuel on the forest floor of Maoershan national forest, China using a LoRa wireless network

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Journal of Forestry Research 2022年第3期33卷 899-909页

作者： Bo peng Jiawei Zhang Jian xing Jiuqing Liu Northeast Forestry University Harbin150040People’s Republic of China

The moisture content of dead forest fuel is an important indicator of risk levels of forest fires and prediction of fire spread. Moisture distribution is important to determine wild fire rating. However, it is often difficult to predict moisture distribution because of a complex terrain, changeable environments and low cover of commercial communication signals inside the forest. This study proposes a moisture content prediction system composed of environmental data collected using a long range radio frequency band 433 MHz wireless sensor network and data processing for moisture prediction based on a BP (back-propagation) neural network. In the fall of 2019, twenty nodes for the collection of environmental data were placed in four forest stands of Maoershan National Forest for a month;7440 sets of data including temperature, humidity, wind speed and air pressure were obtained. Half the data were used as a training set, the other as a testing set for a BP neural network. The results show that the average absolute error between the predicted value and the real value of moisture content of fuels of Larix gmelini, Betula platyphylla, Juglans mandshurica, and Quercus mongolica stands was 0.94%, 0.21%, 0.86%, 0.97%, respectively. The prediction accuracy was relatively high. The proposed distributed moisture content prediction method has the advantages of wide coverage and good real-time performance;at the same time, it is not limited by commercial signals and so it is especially suitable for forest fire prediction in remote mountainous areas.

关键词： Distributed moisture content prediction Dead fuel BP neural network

Elutriation characteristics of multi-component mixtures in a fluidized bed pyrolysis process

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Particuology 2021年第5期19卷 131-138页

作者： xing Wu Jingbo peng Yu Zhang Zhiduo Wang Aeronautics Engineering College Air Force Engineering UniversityXi’an 710038China

Multi-component mixtures were prepared to simulate a bed of walnut shells undergoing pyrolysis in acold fluidized *** mixtures with different ratios of walnut shell,semi-chars,and clean char were *** elutriation experiments using these mixtures were performed in a transparent fluidized bed to allow direct observation of the flow patterns and particle *** results indicated that the bubble wake rather than bubble nose was primarily responsible for particle entrainment at higher gas velocities,and that coarser particles would be“transformed”into elutriable *** gas velocities ranged from 0.2 to 1.0 and an exponential decrease in particle concentration with respect to bed height was *** transport disengagement height(TDH)gradually increased with the gas velocity until the entire bed layer enters a pneumatic transport ***,larger TDHs were required when the bed contained a larger fraction of light *** characteristic parameters were used to evaluate particle elutriation:the elutriation rate constant(K),and the residual volatile content of the elutriated particles(v′).These parameters were used to optimize operating gas velocity for the fluidized bed.

关键词： Fluidized bed Elutriation Multi-component mixture Walnut shell Pyrolysis

Reducing energy barriers of chemical reactions with a nanomicrocell catalyst consisting of integrated active sites in conductive matrices

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Science Bulletin 2019年第6期64卷 385-390页

作者： guo-peng Zhan Chuan-De State Key Laboratory of Silicon Materials Center for Chemistry of High-Performance&Novel MaterialsDepartment of ChemistryZhejiang University

Reducing energy barriers of chemical reactions is the never-ending endeavor of *** by the high reactivity of primary cells,we develop a nanosized fuel cell catalyst(denoted as nanomicrocell catalyst),consisting of integrated electrode pairs,conductive matrices and electrolytes,to improve the chemical ***,the anodes are Pd species which is combining with the electron-rich N atoms in B-and-N co-doped carbon dots;the cathodes are electron-deficient B atoms;and the conductive matrices are B-and-N co-doped carbon dots which are connecting with the electrode *** to the reactivity of primary cells,the catalytic properties of the nanomicrocell catalyst in hydrogenation of benzaldehyde are depending on the properties of electrode pairs,conductive matrices and *** unique catalytic properties are attributed to the different substrate adsorption capability and catalytic properties of paired electrodes,and the easy migration of electrons and charge carriers,which could improve the synergetic effect between paired active ***,this work may open up a new window for designed synthesis of advanced catalysts which could highly lower the energy barriers of chemical reactions.

关键词： Nanomicrocell catalysts Conductive matrices Electrode pairs Electrolytes Primary cells