检索结果-南通市图书馆

Global Existence and Asymptotic Behavior of Solutions to a Free Boundary Problem for the 1D Viscous Radiative and Reactive Gas

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2018年第5期34卷 827-842页

作者： chang ming song Hong LI Jian Lin ZHANG Department of Applied Mathematics College of Science Zhongyuan University of Technology Zhengzhou 450007 P. R. China Department of Applied Physics College of Science Zhongyuan University of Technology Zhengzhou 450007 P. R. China

In this paper, we study a free boundary problem for the 1D viscous radiative and reactive gas. We prove that for any large initial data, the problem admits a unique global generalized solution. Meanwhile, we obtain th... 详细信息

关键词： Radiative and reactive gases global solution free boundary problem asymptotic behavior

Time-Periodic Solution to the Compressible Navier–Stokes/Allen–Cahn System

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2020年第4期36卷 419-442页

作者： chang ming song Jian Lin ZHANG Yuan Yuan WANG Department of Applied Mathematics College of ScienceZhongyuan University of TechnologyZhengzhou 450007P.R.China

In this paper,we investigate the time-periodic solution to a coupled compressible Navier–Stokes/Allen–Cahn system which describes the motion of a mixture of two viscous compressible fluids with a time periodic external force in a periodic domain in R^*** existence of the time-periodic solution to the system is established by using an approach of parabolic regularization and combining with the topology degree theory,and then the uniqueness of the period solution is obtained under some smallness and symmetry assumptions on the external force.

关键词： Navier–Stokes equation Allen–Cahn equation two-phase flows time-periodic solution topology degree theory

Influence of Molecular Interaction on Crystallization Behavior of Glycine from Mother Liquor

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2011年第6期27卷 1055-1059页

作者： TAO chang-yuan LI ming-song FAN Xing LIU Zuo-hua DU Jun College of Chemistry and Chemical Engineering Chongqing University Chonqing 400044 P. R. China

The mother liquor for preparing industrial HCN was investigated, to analyze the side-products’ structure and influence of molecular interactions of side-products with glycine and solvent on the glycine’s crystallization process. The side-products（SPs） were super-branched oligmers with plenty of hydrophilic groups, which could affect the crystallization process by interactions such as hydrogen bond. Alcohol-water mixed solvent with different polyols could be used to weaken the SPs-glycine interaction and strengthen the SPs-water interaction, which help to improve the crystallization efficiency and purity. After optimization, SPs’ mass fraction in glycine could be reduced by 80% and the morphology of crystal particles could also be improved.

关键词： Glycine Mother liquor Molecular interaction Mixed solvent Crystallization

Inverse-time Backup Protection Based on Unified Characteristic Equation for Distribution Networks with High Proportion of Distributed Generations

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 202-212页

作者： Nana chang Guobing song Zhongxue chang Yuping Zheng Xingang Yang the School of Electrical Engineering Xi’an Jiaotong UniversityXi’anChina State Key Laboratory of Smart Grid Protection and Control NARI Group CorporationNanjingChina Electric Power Research Institute of State Grid Shanghai Electric Power Company ShanghaiChina

The setting work of backup protection using steady-state current is tedious,and mismatches occasionally occur due to the increased proportion of distributed generations(DGs)connected to the power ***,there is a practical need to study a backup protection technology that does not require step-by-step setting and can be adaptively *** paper proposes an action sequence adaptive to fault positions that uses only positive sequence fault component(PSFC)*** the influence of DGs,the unified time dial setting can be obtained by selecting specific *** protection performance is improved by using the adjacent upstream and downstream protections to meet the coordination time interval in the case of metallic faults at the near-and far-ends of the ***,the expression and implementation scheme for inverse-time backup protection(ITBP)based on the unified characteristic equation is *** results show that this scheme can adapt to DG penetration scenarios and can realize the adaptive coordination of multi-level relays.

关键词： Inverse-time backup protection(ITBP) distributed generation(DG) positive sequence fault component(PSFC)voltage unified characteristic equation adaptive coordination

Mn-modified nitrogen-doped Pt-based electrocatalyst for efficient oxygen reduction in aluminum-air batteries

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7126-7135页

作者： Li Gao Yang song Xuebing Xu chang Li Chaoquan Hu State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Zhongke Nanjing Institute of Green Manufacturing Industry Nanjing 211135China

In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction *** size of Pt nanoparticles(NPs)is effectively controlled by doping with Mn and *** the smallest average particle size of 1.7 nm,Mn-Pt/NKB demonstrates half-wave potentials of 0.890 and 0.688 V in the alkaline and neutral electrolytes,respectively,which are superior to those of commercial platinum on activated carbon(Pt/C).When applied as an air cathode in aluminum-air battery,it exhibits ultra-high power densities of 190(alkaline)and 26.2 mW·cm^(−2)(neutral).Moreover,the voltage remains stable after 5 h of *** practical application performance of the Mn-Pt/NKB catalyst in an aluminum-air battery is better than that of commercial Pt/***,the oxygen reduction reaction(ORR)mechanism on surfaces with different particle sizes is analyzed using density functional *** cracking is the major pathway on the surface of the small particles with lower energy consumption of 0.5 eV,while water molecule cleavage is the major pathway on the surface of the large particles with higher energy consumption of 0.97 *** lower energy consumption of the oxygen cracking pathway further confirms the ORR mechanism for higher activity on small-sized *** study provides a direction for the rational design of Pt-based catalysts for ORR and sheds light on the commercial development of aluminum-air batteries.

关键词： oxygen reduction reaction precious metal catalysts aluminum-air battery density functional theory(DFT)calculations reaction pathway

Mathematical Model,Numerical Simulation and Convergence Analysis of a Semiconductor Device Problem with Heat and Magnetic Influences

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 302-319页

作者： chang-feng LI Yi-rang YUAN Huai-ling song School of Economics Shandong UniversityJinan 250100China Institute of Mathematics Shandong UniversityJinan 250100China College of Mathematics and Econometrics Hunan UniversityChangsha 410082China

In this paper,the authors discuss a three-dimensional problem of the semiconductor device type involved its mathematical description,numerical simulation and theoretical *** important factors,heat and magnetic influences are *** mathematical model is formulated by four nonlinear partial differential equations(PDEs),determining four major physical *** influences of magnetic fields are supposed to be weak,and the strength is parallel to the *** elliptic equation is treated by a block-centered method,and the law of conservation is *** computational accuracy is improved one *** equations are convection-dominated,thus are approximated by upwind block-centered *** difference can eliminate numerical dispersion and nonphysical *** diffusion is approximated by the block-centered difference,while the convection term is treated by upwind ***,the unknowns and adjoint functions are computed at the same *** characters play important roles in numerical computations of conductor device *** the theories of priori analysis such as energy estimates,the principle of duality and mathematical inductions,an optimal estimates result is *** a composite numerical method is shown for solving this problem.

关键词： three-dimensional conductor device problem with heat and magnetic influences upwind blockcentered differences elemental conservation of mass numerical analysis

On the Quantum Cohomology of Blow-ups of Four-dimensional Quadrics

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第1期40卷 313-328页

作者： Jian Xun HU Hua Zhong KE chang Zheng LI Lei song School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

We propose a conjecture relevant to Galkin’s lower bound conjecture,and verify it for the blow-ups of a four-dimensional quadric at a point or along a projective *** also show that Conjecture O holds in these two cases.

关键词： Quantum cohomology blow-up quadric hypersurface

Intrinsic pentagon defect engineering in multiple spatial-scale carbon frameworks for efficient triiodide reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 20-28,I0002页

作者： Siyi Hou Xuedan song chang Yu Jiangwei chang Yiwang Ding Yingbin Liu Xiubo Zhang Weizhe Liu Jieshan Qiu State Key Lab of Fine Chemicals Liaoning Key Lab for Energy Materials and Chemical EngineeringFrontier Science Center for Smart MaterialsSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina Liaoning Key Lab for Energy Materials and Chemical Engineering Frontier Science Center for Smart MaterialsSchool of ChemistryDalian University of TechnologyDalian 116024LiaoningChina State Key Laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon ***,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging ***,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center *** experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-π*** multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive *** defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the *** work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts.

关键词： Defect engineering Pentagon carbon Carbon quantum dots Electrocatalytic activity Triiodide reduction

Patent-based technological developments and surfactants application of lithium-ion batteries fire-extinguishing agent

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 39-63,I0002页

作者： Jianqi Zhang Tao Fan Shuai Yuan Chongye chang Kuo Wang Ziwei song Xinming Qian State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100084China Industrial Safety Research Institute China Academy of Safety Science and TechnologyBeijing 100012China Fire Engineering Department China People’s Police UniversityLangfang 065000HebeiChina

While newer,more efficient Lithium-ion batteries(LIBs)and extinguishing agents have been developed to reduce the occurrence of thermal runaway accidents,there is still a scarcity of research focused on the application of surfactants in different LIBs extinguishing agents,particularly in terms of patented *** aim of this review paper is to provide an overview of the technological progress of LIBs and LIBs extinguishing agents in terms of patents in Korea,Japan,Europe,the United States,China,*** initial part of this review paper is sort out LIBs technology development in different *** addition,to compare LIBs extinguishing agent progress and challenges of liquid,solid,combination of multiple,and *** subsequent section of this review focuses on an in-depth analysis dedicated to the efficiency and challenges faced by the surfactants corresponding design principles of LIBs extinguishing agents,such as nonionic and anionic surfactants.A total of 451,760 LIBs-related patent and 20 LIBs-fire-extinguishing agent-related patent were included in the *** extinguishing effect,cooling performance,and anti-recombustion on different agents have been *** a comprehensive comparison of these agents,this review suggests that temperature-sensitive hydrogel extinguishing agent is ideal for the effective control of LIBs *** progress and challenges of surfactants have been extensively examined,focusing on key factors such as surface activity,thermal stability,foaming properties,environmental friendliness,and electrical ***,it is crucial to emphasize that the selection of a suitable surfactant must align with the extinguishing strategy of the extinguishing agent for optimal firefighting effectiveness.

关键词： LIBs Fire-extinguishing agent Surfactants Patent