检索结果-南通市图书馆

Journal of Systems Science & Complexity 2024年第1期37卷 136-151页

作者： PAn Zini CHEn.ben M Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem for n-dimensional systems and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull formed by the ***,the dynamics of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the communication network and collision avoidance among the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a numerical example.

关键词： Multi-agent systems networked systems target fencing

心脏MRI评估右室功能预测植入心脏复律除颤器病人的心血管事件

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2022年第1期 105-105页

作者： L.Jimenez-Juan n.ben-dov C.V.Goncalves Frazao n.S.Tan S.M.Singh P.Dorian 白雪

摘要右心室射血分数（RVEF）是各种心脏疾病病人死亡和心血管不良结局的独立预测因子。目的探讨心脏MRI测量的RVEF可否预测植入型心律转复除颤器（ICD）病人在

关键词：

Stability Analysis and Performance Evaluation of Additive Mixed-Precision Runge-Kutta Methods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 705-738页

作者： ben Burnett Sigal Gottlieb Zachary J.Grant Center for Scientific Computing and Data Science Research UMass DartmouthNorth DartmouthMassachusettsUSA CSME Michigan State UniversityEast LansingMichiganUSA

Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and *** specially designed methods use reduced precision for the implicit computations and full precision for the explicit *** this work,we analyze the stability properties of these methods and their sensitivity to the low-precision rounding errors,and demonstrate their performance in terms of accuracy and *** develop codes in FORTRAn and Julia to solve nonlinear systems of ODEs and PDEs using the mixed-precision additive Runge-Kutta(MP-ARK)*** convergence,accuracy,and runtime of these methods are *** show that for a given level of accuracy,suitably chosen MP-ARK methods may provide significant reductions in runtime.

关键词： Mixed precision Runge-Kutta methods Additive methods Accuracy

Exploring charge and spin fluctuations in infinite-layer cuprate SrCuO_(2)from a phonon perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 159-167页

作者： Xin Du Pei-Han Sun.ben-Chao Gong Jian-Feng Zhang Zhong-Yi Lu Kai Liu Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices Renmin University of ChinaBeijing 100872China Department of Physics School of ScienceJiangsu University of Science and TechnologyZhenjiang 212100China Institute of Physics Chinese Academy of SciencesBeijing 100190China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

The infinite-layer cuprate ACu O_(2)(A=Ca,Sr,Ba)possesses the simplest crystal structure among numerous cuprate superconductors and can serve as a prototypical system to explore the unconventional *** on the first-principles electronic structure calculations,we have studied the electronic and magnetic properties of the infinite-layer cuprate SrCuO_(2)from a phonon *** find that interesting fluctuations of charges,electrical dipoles,and local magnetic moments can be induced by the atomic displacements of phonon modes in SrCuO_(2)upon the hole *** all optical phonon modes of SrCuO_(2)in the antiferromagnetic néel state,only the A_(1g)mode that involves the full-breathing O vibrations along the Cu-O bonds can cause significant fluctuations of local magnetic moments on O atoms and dramatic charge redistributions between Cu and O ***,due to the atomic displacements of the A_(1g)mode,both the charge fluctuations on Cu and the electrical dipoles on O show a dome-like evolution with increasing hole doping,quite similar to the experimentally observed behavior of the superconducting T_(c);in comparison,the fluctuations of local magnetic moments on O display a monotonic enhancement along with the hole *** analyses indicate that around the optimal doping,there exists a large softening in the frequency of the A_(1g)phonon mode and a van Hove singularity in the electronic structure close to the Fermi level,suggesting potential electron-phonon *** work reveals the important role of the full-breathing O phonon mode playing in the infinite-layer SrCuO_(2),which may provide new insights in understanding the cuprate superconductivity.

关键词： first-principles calculations cuprate superconductors phonon charge and spin fluctuations

Multistimuli-Responsive Luminescent Porous Organic Polymers with Chiroptical Properties and Acid-Induced Degradation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第16期42卷 1886-1894页

作者： Youling He Dongyang Fan Liang Zhang Dong Wang Ting Han Rongrong Hu ben Zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhenGuangdong 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhenGuangdong 518060China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong999077China State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China Universityof TechnologyGuangzhouGuangdong 510640China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhen(CUHK-Shenzhen)Guangdong 518172China

Porous organic polymers(POPs)have attracted great attention in past *** diverse functional POPs have been developed,multistimuli-responsive POPs with excellent aggregate-state luminescence together with good chiroptical properties have rarely been ***,two pairs of Salen-type enantiomeric PoPs with multistimuli-responsive luminescence and chiral features were designed and synthesized by facile polycondensation reactions between polyfunctional aggregation-induced emission luminogen(AlEgen)-containing salicylaldehyde derivatives and chiral *** Salen units in polymer backbones as tetradentate ligands,a series of POP-metal complexes were further *** obtained POPs and metal complexes show good porosity,high thermal stability,and obvious circular dichroism ***,benefiting from the coexistence of AlEgen and Salen units in polymer structures,these POPs exhibit excellent luminescence performance in aggregate states and tunable fluorescence behaviors in response to external stimuli of Zn^(2+)ion,mechanical forces,organic solvent,and *** to the dynamic feature of Schiff base C=n bonds,the present POPs can efficiently undergo hydrolysis reactions under strong acidic conditions to reproduce the AlEgencontaining monomers,and such an acid-induced degradation process can be directly visualized and dynamically monitored via fluorescence *** properties collectively make the POPs candidate materials for applications in heterogeneous asymmetric catalysis,fluorescence sensing,biomedicine,etc.

关键词： Polymers Stimuli-responsive luminescence Porous polymers Chirality Aggregation-induced emission Fluorescence Schiff bases Degradation

natural Convection of a Power-Law nanofluid in a Square Cavity with a Vertical Fin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第9期20卷 2091-2108页

作者： Amira M’hadbi Mohammed El Ganaoui Haïkel ben Hamed Amenallah Guizani Khalid Chtaibi LERMAB Department of Transition and Energy Efficiency ProfessionsIUT H Poincaréde LongwyUniversity of LorraineLongwy54400France LPT Center for Energy Research and Technologies(Borj Cedria2084)University of Tunis El ManarTunis1068Tunisia LTI Department of Mechanical Engineering and ProductionIUTUniversity of Picardie Jules-VerneAmiens80025France

The behavior of non-newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated *** particular,the impact of nanofluids,composed of water and Al_(2)O_(3),TiO_(2),and Cu nanoparticles,on heat transfer enhancement is *** aim of this research is also to analyze the influence of different parameters,including the Rayleigh number(Ra=10^(4)-10^(6)),nanoparticle volume fraction(φ=0%-20%),non-newtonian power-law indexes(n=0.6-1.4),and fin dimensions(Ar=0.3,0.5,and 0.7).Streamlines and isotherms are used to depict flow and related heat transfer *** indicate that thermal performance improves with increasing Rayleigh number,regardless of the nanoparticle type or nanofluid rheological *** suggests that the buoyancy force has a significant impact on heat transfer,particularly near the heat *** nusselt number is more sensitive to variations in Cu nanoparticle volume fractions compared to Al₂O₃and TiO₂.Moreover,the average nusselt numbers for power-law nanofluids with nn>1)are greater(smaller)than for newtonian fluids due to the decrease(increase)in viscosity with increasing(decreasing)shear rate,at the same values of Rayleigh number Ra owing to the amplification(attenuation)of the convective ***,the most substantial enhancement is observed with Cu-water shear-thinning nanofluid,where the nusselt number increases by 136%when changing from newtonian to shear thinning behavior and by 154.9%when adding 16%nanoparticle volume ***,an even larger increase of 57%in the average nusselt number is obtained on increasing the fin length from 0.3 to 0.7.

关键词： Heat transfer nanofluid non-newtonian fluid natural convection

Experimental design of paraffin/methylated melamine-formaldehyde microencapsulated composite phase change material and the application in battery thermal management system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 124-136页

作者： Que Huang Silong Wang Jichun He Dengji Xu Safaa nAbdou Mohamed MIbrahim Shiqi Sun Yanjun Chen Handong Li ben Bin Xu Changcheng Liu Zeinhom M.El-Bahy Zhanhu Guo School of Environment and Safety Engineering North University of ChinaTaiyuan 030051China Institute of Advanced Energy Materials and Systems North University of ChinaTaiyuan 030051China School of Resources and Safety Engineering Central South UniversityChangsha 410010China School of Medical and BioInformation Engineering Northeastern UniversityShenyang 110819China Department of Chemistry Khurmah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon Tyne NE18STUK College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City 11884CairoEgypt

In order to maintain the optimal operating temperature of the battery surface and meet the demand for thermal storage technology,battery thermal management system based on phase change materials has attracted increasing *** this work,a kind of core-shell structured microcapsule was synthesized by an in-situ polymerization,where paraffin was used as the core,while methanol was applied to mod-ify the melamine-formaldehyde shell to reduce toxicity and improve thermal ***,three different types of heat conductive fillers with the same content of 10 wt.%,i.e.,nano-Al_(2)O_(3),nano-ZnO and carbon nanotubes were added,generating *** microcapsules were uniform,and were not affected by the thermal fillers,which were evenly dispersed *** composite sample with carbon nanotubes(10 wt.%)showed the highest thermal conductivity of 0.50 W/(m K)and latent heat of 139.64 J/***,according to the leakage testing and battery charge/discharge experiments,compared with Al_(2)O_(3)and ZnO,the addition of carbon nanotubes remarkably enhances the heat storage ability as latent heat from 126.98 J/g for the prepared sample with Al_(2)O_(3)and 125.86 J/g for the one with ZnO,then to 139.64 J/g,as well as dissipation performance as a cooling effect by decreasing the sur-face temperature of battery from 2%to 12%of microcapsule,composite sample with carbon nanotubes presents a broad application prospect in battery thermal management system and energy storage field.

关键词： Microcapsule Phase change material Battery Carbon nanotube Safety

Strong metal–support interaction boosts the electrocatalytic hydrogen evolution capability of Ru nanoparticles supported on titanium nitride

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第1期6卷 245-254页

作者： Xin Wang Xiaoli Yang Guangxian Pei Jifa Yang Junzhe Liu Fengwang Zhao Fayi Jin Wei Jiang Haoxi ben Lixue Zhang College of Chemistry and Chemical Engineering Collaborative Innovation Center for Hydrogen Energy Key Materials and Technologies of Shandong ProvinceQingdao UniversityQingdaoShandongChina State Key Laboratory of Bio-fibers and Eco-Textiles Qingdao UniversityQingdaoShandongChina Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of ScienceQingdaoShandongChina

Ruthenium(Ru)has been regarded as one of the most promising alternatives to substitute Pt for catalyzing alkaline hydrogen evolution reaction(HER),owing to its inherent high activity and being the cheapest platinum-group ***,based on the idea of strong metal–support interaction(SMSI)regulation,Ru/Tin catalysts with different degrees of Tin overlayer over Ru nanoparticles were fabricated,which were applied to the alkaline electrolytic *** reveal that the Tin overlayer would gradually encapsulate the Ru nanoparticles and induce more electron transfer from Ru nanoparticles to Tin support by the Ru–n–Ti bond as the SMSI degree *** study shows that the exposed Ru–Tin interfaces greatly promote the H_(2) desorption ***,the Ru/Tin-300 with a moderate SMSI degree exhibits excellent HER performance,with an overpotential of 38 mV at 10 mA cm^(−2).Also,due to the encapsulation role of Tin overlayer on Ru nanoparticles,it displays super long-term stability with a very slight potential change after 24 *** study provides a deep insight into the influence of the SMSI effect between Ru and Tin on HER and offers a novel approach for preparing efficient and stable HER electrocatalysts through SMSI engineering.

关键词： electronic structure hydrogen evolution reaction ruthenium strong metal-support interaction titanium nitride

Magnetic and specific heat studies of the frustrated Er_2Mn_2O_7 compound

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2013年第1期31卷 54-59页

作者： n.ben Amor M.Bejar E.Dhahri M.A.Valente P.Lachkar E.K.Hlil Laboratory of Applied Physics Faculty of Sciences of SfaxBP 1171University of Sfax I3n and Physics Department University of Aveiro MCMF Néel InstitutCNRS25 avenue des MartyrsBuilding FBP 16638042 Grenoble cedex 9France MCBT Institut NéelCNRS25 avenue des MartyrsBuilding EBP 16638042 Grenoble cedex 9France

A new ErzMn207 compound was synthesized by the ceramic method and its crystal structure was characterized LJsing powder X-ray diffraction （XRD） and observed by scanning electron microscopy （SEM）. The magnetic properties were investigated using a BS2 magnetometer and the heat capacity was studied using a quantum design （PPMS）. The structural study revealed that this compound was monophasic and crystallized in the monoclinic system with the P2/M space group. Magnetization measurements were carried out in the temperature range of 1.8-200 K under an applied magnetic field of 0.05 T. A crossover from a room temperature para- magnetic phase to an antiferromagnetic one at low temperature was detected from the magnetic study. The magnetic susceptibility, in the paramagnetic region above 40 K, was found to present a simple Curie-Weiss type behavior. From the specific heat （G,） measurements in magnetic fields up to 5 T, we noted the presence of a wide peak characteristic of a second order magneto-structural transition.

关键词： magnetic frustration magnetic phase transition specific heat rare earths

Comparison of *** oxygen plasma and chemical treatments for surface modifications of Ti6Al4V

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2019年第2期2卷 65-75页

作者： María Elena Alemán.Domínguez Zaida Ortega Antonio n.benítez Aday Romero.Pérez Ling Wang Ruymán Santana.Farré Francisco Rodríguez.Esparragón Departamento de Ingeniería de Procesos Universidad de Las Palmas de Gran CanariaCampus universitario de Tafira Baja35017 Las Palmas de Gran CanariaSpain Departamento de Ingeniería Mecánica Universidad de Las Palmas de Gran CanariaCampus universitario de Tafira Baja35017 Las Palmas de Gran CanariaSpain State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityScience and Technology Park of Xi’an Jiaotong UniversityYanta DistrictXi’an City 710054Shaanxi ProvincePeople’s Republic of China Research Unit Dr.Negrín University Hospital35019 Las PalmasCanary IslandsSpain

Different treatments were conducted over Ti6Al4V samples in order to produce a surface modification to increase cell attachment and *** surface treatments evaluated in this study were as follows:etching with sulfuric acid/hydrochloric acid,oxidizing with hydrogen peroxide and low-pressure oxygen plasma *** contrast to other works found in the literature,this research conducts a comparison between different chemical and physical treatments in terms of different assays for surface characterization:X-ray diffraction,scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy,water contact angle,release of vanadium ions and cell viability tests(MTT)of human osteoblasts(hFOB 1.19).Cell morphology over the different substrates was also studied by SEM *** was found that plasma and peroxide treatments increase the O/Ti ratio at the titanium surface and provide an increase in cell *** the other hand,acid etching provides a superhydrophilic surface which is not able to improve the cell attachment of human osteoblasts.

关键词： Surface activation Titanium alloys Surface functionalization Low-pressure plasma