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Maximal Regularity of Second Order Delay Equations in Banach Spaces

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Acta Mathematica Sinica,English Series 2009年第1期25卷 21-28页

作者： Shang quan bu Department of Mathematical Science Tsinghua University Beijing 100084 P. R. China

Using known Ca-multiplier result, we give necessary and sufficient conditions for the second order delay equations：u″（t）=Au（t）＋Fut＋Gu′＋f（t）,t∈Rto have maximal regularity in HSlder continuous function spaces C^α （R, X）, where X is a Banach space, A is a closed operator in X, F, G ∈L（C（[-r, 0], X）, X） are delay operators for some fixed r 〉 0.

关键词： maximal regularity delay equations Hoelder continuous functions C^α-multiplier

Well-Posedness of Equations with Fractional Derivative via the Method of Sum

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Acta Mathematica Sinica,English Series 2012年第1期28卷 37-44页

作者： Shang quan bu Department of Mathematical Science University of Tsinghua

We study the well-posedness of the equations with fractional derivative D^αu（t）= Au（t）＋ f（t）（0 ≤ t ≤ 2π）, where A is a closed operator in a Banach space X, 0 〈 α 〈 1 and D^αis the fractional derivative in the sense of Weyl. Although this problem is not always well-posed in L^P（0, 2π; X） or periodic continuous function spaces Cper（[0, 2π]; X）, we show by using the method of sum that it is well-posed in some subspaces of L^P（0, 2π; X） or Cper （[0, 2π]; X）.

关键词： Well-posedness fractional derivative the method of sum real interpolation spaces fractional Sobolev spaces

Periodic Solutions of Third-order Differential Equations with Finite Delay in Vector-valued Functional Spaces

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Acta Mathematica Sinica,English Series 2019年第1期35卷 105-122页

作者： Shang quan bu Gang CAI Department of Mathematical Sciences Tsinghua UniversityBeijing 100084P.R.China School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

In this paper, we study the well-posedness of the third-order differential equation with finite delay(P3): αu’"(t) + u"(t) = Au(t) + bu’(t) + Fut +f(t)(t ∈ T := [0,2π]) with periodic boundary conditions u(0) = u(2π), u’(0) = u"(2π),u"(0)=u"(2π) in periodic Lebesgue-Bochner spaces Lp(T;X) and periodic Besov spaces Bp,qs(T;X), where A and B are closed linear operators on a Banach space X satisfying D(A) ∩ D(B) ≠ {0}, α≠ 0 is a fixed constant and F is a bounded linear operator from Lp([-2π, 0];X)(resp. Bp,qs([-2π, 0];X)) into X, ut is given by ut(s) = u(t + s) when s ∈ [-2π,0]. Necessary and sufficient conditions for the Lp-well-posedness(resp. Bp,qs-well-posedness)of(P3) are given in the above two function spaces. We also give concrete examples that our abstract results may be applied.

关键词： Well-posedness delay equations Fourier multiplier Lebesgue-Bochner spaces Besov spaces

The Promoting Effect of Multifunctional Groups on the Thermal and Mechanical Properties of PVC Materials

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Journal of Renewable Materials 2023年第2期11卷 867-880页

作者： Mei Wang Xinzhu Fan Xianghai Song quan bu School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Institute of the Green Chemistry and Chemical Technology School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang212013China

The development of PVC materials grafted with mannich base originated from myrcene(P-MAM-g,where the mannich base derived from myrcene is abbreviated as MAM)via green and effective synthetic methods is a good strategy to avoid unacceptable discoloration and deterioration of thermal and mechanical properties caused by autocatalytic dehydrochlorination(DHC)during PVC *** this study,MAM with double bonds,amino groups,ester groups,and phospholipid groups was introduced into the chains of PVC to improve the thermal stability of *** experimental results showed that the covalent attachment of MAM to PVC enhanced both the initial and the long-term stability of *** enhanced performance of P-MAM-g compared with unmodified PVC is attributed to the simultaneous introduction of double bonds and amino groups into the PVC *** double bonds trapped the unstable chlorine atoms originated from the degradation of the PVC chain and reacted with the labile macromolecular radicals originated from PVC,thus inhibiting the radical degradation of the PVC ***,the amino groups absorbed the HCl produced in the degradation of PVC,inhibiting the adverse effects of HCl.P-MAM-g displayed better intrinsic flexibility and anti-migration ability of organic functional components compared with the control PVC materials.A possible stabilizing mechanism of the P-MAM-g was also presented.

关键词： Myrcene poly(vinyl chloride) covalent grafting self-stabilization

An improved genetic algorithm for searching for pollution sources

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Water Science and Engineering 2013年第4期6卷 392-401页

作者： quan-min bu Zhan-jun WANG Xing TONG School of Government Nanjing University Center for Social Risk and Public Crisis Management of Nanjing University Institute of Chemical Industry of Forest Products

As an optimization method that has experienced rapid development over the past 20 years, the genetic algorithm has been successfully applied in many fields, but it requires repeated searches based on the characteristics of high-speed computer calculation and conditions of the known relationship between the objective function and independent variables. There are several hundred generations of evolvement, but the functional relationship is unknown in pollution source searches. Therefore, the genetic algorithm cannot be used directly. Certain improvements need to be made based on the actual situation, so that the genetic algorithm can adapt to the actual conditions of environmental problems, and can be used in environmental monitoring and environmental quality assessment. Therefore, a series of methods are proposed for the improvement of the genetic algorithm：（1） the initial generation of individual groups should be artificially set and move from lightly polluted areas to heavily polluted areas; （2） intervention measures should be introduced in the competition between individuals; （3） guide individuals should be added; and （4） specific improvement programs should be put forward. Finally, the scientific rigor and rationality of the improved genetic algorithm are proven through an example.

关键词： genetic algorithm fitness selection crossover mutation pollution sources

Synergistic Modification of PVC with Nitrogen-Containing Heterocycle and Tung-Oil Based Derivative for Enhanced Heat Stabilization and Plasticization Behavior

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Journal of Renewable Materials 2023年第4期11卷 2015-2031页

作者： Mei Wang Xinzhu Fan quan bu Puyou Jia Shouqi Yuan School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Institute of Chemical Industry of Forest Products Chinese Academy of Forestry(CAF)Nanjing210042China Key Laboratory of Chemistry and Engineering of Forest Products State Ethnic Affairs CommissionGuangxi Key Laboratory of Chemistry and Engineering of Forest ProductsGuangxi University for NationalitiesNanning530006China Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China

The additives present in polyvinyl chloride(PVC)materials are the major source of organic by-products during PVC *** thermal stabilizer and plasticizer are the main additives that endow PVC with the required properties during its ***,these two additives easily migrate when samples are obtained by physical mixing of the additives with *** causes the reduction of PVC sample efficacy and the increase in the formation of organic by-products in the radiolysis *** this work,two kinds of grafted PVC samples(tungoil derivative grafted PVC and Atz grafted PVC,abbreviated as P-GT4 and P-AZ3)were synthesized by chemical grafting of 3-amino-1,2,4-triazole(Atz)and tung-oil derivative on PVC,*** two PVC samples were then blended at different mass ratios to obtain hybrid PVC materials with excellent plasticization,thermal stability and migration resistance *** scanning calorimetry(DSC),discoloration,Congo red test and thermogravimetric analysis(TGA)showed that when the mass ratio of P-GT4 to P-AZ3 in the mixed PVC resin was 1:3,the resulting P1:3-GT4-AZ3(P4)presented the best plasticization and thermal *** kinetics of thermal decomposition showed that the activation energy of P4 was much higher than that of the reference material[PVC/DOTP/CaSt2/ZnSt2,PVC/CZ41 for short]at mass lossα=20%and 80%.In addition,the leaching test showed that P4 material possessed excellent migration resistance ability.

关键词： Polyvinyl chloride synergistic self-stabilization internal plasticization 3-amino-1,2,4-triazole tung-oil derivative

Study on the Performance of the GRANDProto300 Particle Detector Array by Simulation

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Research in Astronomy and Astrophysics 2024年第1期24卷 173-177页

作者： Fu-Lin Dai quan-bu Gou Xiaoyuan Huang Yi-Qing Guo Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The Giant Radio Array for Neutrino Detection(GRAND)is a proposed large-scale observatory designed to detect cosmic rays,gamma-rays,and neutrinos with energies exceeding 100 Pe *** GRANDProto300 experiment is proposed as the early stage of the GRAND project,consisting of a hybrid array of radio antennas and scintillator *** latter,as a mature and traditional detector,is used to cross-check the nature of the candidate events selected from radio *** this study,we developed a simulation software called G4GRANDProto300,based on the Geant4 software package,to optimize the spacing of the scintillator detector array and to investigate its effective *** analysis was conducted at various zenith angles under different detector spacings,including 300,500,600,700,and 900 *** results indicate that,for large zenith angles used to search for cosmic-ray in the GRAND project,the optimized effective area is with a detector spacing of 500 *** G4GRANDProto300 software that we developed could be used to further optimize the layout of the particle detector array in future work.

关键词： astroparticle physics instrumentation:detectors (ISM:)cosmic rays

Preparation and performance of highly-conductive dual-doped Li_(7)La_(3)Zr_(2)O_(12)solid electrolytes for thermal batteries

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Green Energy & Environment 2025年第2期10卷 399-409页

作者： Wei Li Shu Zhang Xinya bu Jing Luo Yi Zhang Mengyu Yan Ting quan Yanli Zhu State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of TechnologyBeijing100081China Xi'an North Qinghua Electromechanical Co. Ltd.Xi'an710025China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

Garnet Li_(7)La_(3)Zr_(2)O_(12)(LLZO)electrolytes have been recognized as a promising candidate to replace liquid/molten-state electrolytes in battery applications due to their exceptional performance,particularly Ga-doped LLZO(LLZGO),which exhibits high ionic ***,the limited size of the Liþtransport bottleneck restricts its high-current discharging *** present study focuses on the synthesis of Ga^(3+)þand Ba^(2+)þco-doped LLZO(LLZGBO)and investigates the influence of doping contents on the morphology,crystal structure,Liþtransport bottleneck size,and ionic *** particular,Ga_(0.32)Ba_(0.15)exhibits the highest ionic conductivity(6.11E-2 S cm^(-1) at 550 C)in comparison with other compositions,which can be attributed to its higher-energy morphology,larger bottleneck and unique Liþtransport *** addition to Ba^(2+),Sr^(2+)þand Ca^(2+)have been co-doped with Ga3þinto LLZO,respectively,to study the effect of doping ion radius on crystal structures and the properties of *** characterization results demonstrate that the easier Liþtransport and higher ionic conductivity can be obtained when the electrolyte is doped with larger-radius *** a result,the assembled thermal battery with Ga_(0.32)Ba_(0.15)-LLZO electrolyte exhibits a remarkable voltage platform of 1.81 V and a high specific capacity of 455.65 mA h g^(-1) at an elevated temperature of 525℃.The discharge specific capacity of the thermal cell at 500 mA amounts to 63%of that at 100 mA,showcasing exceptional high-current discharging *** assembled as prototypes with fourteen single cells connected in series,the thermal batteries deliver an activation time of 38 ms and a discharge time of 32 s with the current density of 100 mA cm^(-2).These findings suggest that Ga,Ba co-doped LLZO solid-state electrolytes with high ionic conductivities holds great potential for high-capacity,quick-initiating and high-current discharging thermal batteries.

关键词： Element doping Thermal battery Solid electrolyte LLZO Ionic conductivity

Chapter 6 Multimessenger Physics

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Chinese Physics C 2022年第3期46卷 139-152页

作者： Zhuo Li Giuseppe Di Sciascio quan-bu Gou Yi-Qing Guo Hao-Ning He Ruo-Yu Liu Kai Wang INFN-Roma Tor Vergata Via della Ricerca Scientifica 100133 RomeItaly Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210023China Department of Astronomy School of PhysicsHuazhong University of Science and TechnologyWuhan 430074China

Combining observations of multi-messengers help in boosting the sensitivity of astrophysical source searches,and probe various aspects of the source *** this chapter we discuss how LHAASO observations of very high energy(VHE)gamma rays in combination with telescopes for the other messengers can help in solving the origins of VHE neutrinos and galactic and extragalactic cosmic rays.

关键词： Cosmic ray gamma-ray neutrino LHAASO