检索结果-南通市图书馆

Embedding Derivatives and Integration Operators on Hardy Type Tent Spaces

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第6期38卷 1069-1093页

作者： mao Fa WANG Lv ZHOU School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

In this paper,we completely characterize the positive Borel measuresμon the unit ball B_(n)such that the differential type operator r^(m)of order m∈N is bounded from Hardy type tent space HT_(q,α)^(p)(B_(n))into L^(s)(μ)for full range of p,q,s,α.Subsequently,the corresponding compact description of differential type operator r^(m)is also *** an application,we obtain the boundedness and compactness of integration operator j_(g)from HT_(q,α)^(p)(B_(n))toHT_(s,β)^(t)(B_(n)),and the methods used here are adaptable to the Hardy spaces.

关键词： Embedding derivative integration operator Hardy type tent space Carleson measure

range walk and array rotation in space-time adaptive processing:effects and compensations

在线全文

学校读者我要写书评

暂无评论

journal of Systems Engineering and Electronics 2010年第4期21卷 537-543页

作者： jinping Sun Guohua Wang Shiyi mao School of Electronic and Information Engineering Beihang University Beijing 100191 P. R. China School of Electrical and Electronic Engineering Nanyang Technological University Nanyang Avenue 639798 Singapore

This paper proposes a unified clutter model incorporating the effects of range walk and array rotation for space-time adaptive processing（STAP） in airborne multi-channel early-warning *** on this clutter model,STAP performance is then analyzed from the perspective of covariance matrix tapering（CMT）.For STAP performance degradation due to array rotation,a determinate compensation method is proposed based on the CMT *** examples are provided to verify the analysis and the proposed compensation method.

关键词： radar space-time adaptive processing clutter covariance matrix tapering.

Opposite relationship between Orientation Selection and Texture Memory in the Deformed Electrical Steel Sheets during α→γ→α Transformation

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2017年第12期33卷 1522-1530页

作者： Louwen Zhang Ping Yang Weimin mao School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

The undesired {111} texture component for the magnetic properties mainly exists in the sheets of electrical steels by the conventional process, whereas the sheets with the non-{111} texture can be obtained by α→γ→α transformation. In this paper, we mainly investigate the opposite relationship between orientation selection and texture memory in the deformed ultra-low carbon steel sheet during →→ transformation annealing. A 0.5 mm thick hot-rolled sheet is directly subjected to transformation. The result shows that the specific transformation textures are not possible to generate in the sheets without deformation. Besides, transformation annealing is conducted on the recrystallized sheets in hydrogen and vacuum, respectively. The near {100} and {110} grains have the growth advantage at the atmosphere/metal interface, and the initial ferrite textures are retained in vacuum. Cold-rolled sheets with different thicknesses are annealed for transformation in vacuum, hydrogen and nitrogen, *** near {100} and {110} textures are still the preferential orientations at the atmosphere/metal interface. When the surface grains have sufficiently large growth advantage, the {111} grains developed by texture memory effect will be annexed. Otherwise, the {111} grains at the center layer of the sheets are hard to be replaced, and they are retained after α→γ→α transformation cycle. The results of deformed sheets annealed with different heating rates in hydrogen show that the growth of initial recrystallization grains has a great effect on variant selection.

关键词： Orientation selection Texture memory Electrical steels α→γ→α transformation Electron back-scatter diffraction

Experimental study of hydrogen-rich/oxygen-rich gas–gas injectors

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2013年第5期26卷 1164-1172页

作者： jin Ping Li mao Cai Guobiao School of Astronautics Beihang University

Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injector, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor＇s wall temperatures were obtained for different design parameters through the experiments. It can be con- cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.

关键词： Combustion performance Experiment Gas-gas injector High mass flow rate Wall temperature

A self-tuning control method for Wiener nonlinear systems and its application to process control problems

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Chemical Engineering 2017年第2期25卷 193-201页

作者： Ping Yuan Bi Zhang Zhizhong mao College of Information Science & Engineering Northeastern University Shenyang 110819 China State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang 110819 China

Many chemical processes can be modeled as Wiener models, which consist of a linear dynamic subsystem followed by a static nonlinear block. In this paper, an effective discrete-time adaptive control method is proposed for Wiener nonlinear systems with uncertainties. The parameterization model is derived based on the inverse of the nonlinear function block. The adaptive control method is motivated by self-tuning control and is derived from a modified Clarke criterion function, which considers both tracking properties and control efforts. The uncertain parameters are updated by a recursive least squares algorithm and the control law exhibits an explicit form. The closed-loop system stability properties are discussed. To demonstrate the effectiveness of the obtained results, two groups of simulation examples including an application to composition control in a continuously stirred tank reactor(CSTr) system are studied.

关键词： Wiener systemsAdaptive controlUncertaintiesStabilityCSTr

Theoretical investigation on water/metal fuel ramjet motor-thermodynamic cycle and thermodynamic calculation

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2010年第5期25卷 1129-1138页

作者： YANG Ya-jing HE mao-gang School of Aerospace Xi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in order to obtain specific impulse as great as possible,a dual water injection system is taken into account. Then thermodynamic cycle model,which lead the improvement of power plant and energy system,is introduced in detail,and thermal efficiency is also analyzed. Furthermore,for investigating the performance of this kind of engine system,detailed thermodynamic calculation and analysis are achieved. Especially,regarding hydroreactive metal fuel Mg/AP/HTPB as our target fuel-rich propellant,considering its obvious deficient oxygen property and the energy property of magnesium/water reaction,theoretical calculation method is established by integrating chemical non-equilibrium with chemical equilibrium. Accordingly,low limit of primary water/fuel ratio is determined. In addition,the qualitative and quantitative relationship of performance parameters,such as theoretical specific impulse,nozzle exit temperature,characteristic velocity,etc.,versus water/fuel ratio is investigated respectively.

关键词： hydroreactive metal fuel water ramjet thermodynamic cycle thermal efficiency specific impulse

Polymersome formation by solvent annealing-induced structural reengineering under 3D soft confinement

在线全文

学校读者我要写书评

暂无评论

Nano research 2021年第12期14卷 4644-4649页

作者： Xi mao Hao Li jinwoo Kim Shuai Deng renhua Deng Bumjoon j.Kim jintao Zhu Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education(HUST) and State Key Laboratory of Materials Processing and Die&Mold TechnologySchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan430074China Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon34141Republic of Korea

A solvent annealing-induced structural reengineering approach is exploited to fabricate polymersomes from block copolymers that are hard to form vesicles through the traditional solution self-assembly *** specifically,polystyrene-b-poly(4-vinyl pyridine)(PS-b-P4VP)particles with sphere-within-sphere structure(SS particles)are prepared by three-dimensional(3D)soft-confined assembly through emulsion-solvent evaporation,followed by 3D soft-confined solvent annealing upon the SS particles in aqueous dispersions for structural engineering.A water-miscible solvent(e.g.,THF)is employed for annealing,which results in dramatic transitions of the assemblies,e.g.,from SS particles to *** approach works for PS-b-P4VP in a wide range of block ***,this method enables effective encapsulation/loading of cargoes such as fluorescent dyes and metal nanoparticles,which offers a new route to prepare polymersomes that could be applied for cargo release,diagnostic imaging,and nanoreactor,etc.

关键词： polymersome block copolymer three-dimensional(3D)confinement self-assembly solvent annealing

Comparative investigation on the heat transfer performance of an energy storage system with a spiral tube and straight tube:An experimental approach

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

Science China(Technological Sciences) 2023年第1期66卷 71-85页

作者： mao Qianjun CAO Yan LI Tao School of Urban Construction Wuhan University of Science and TechnologyWuhan 430065China

Latent heat thermal energy storage systems can effectively fill the gap between energy storage and application, and phase-change materials(PCMs) are crucial media for storing thermal energy. Therefore, how to maximize the utilization efficiency of PCMs has attracted widespread attention. In this study, the thermal behavior of two thermal storage units employing a spiral tube and straight tube as heat transfer tubes was experimentally researched and comprehensively compared. Stefan numbers were used to investigate the impact of the heat transfer fluid temperature on the PCM melting process. The temperature distribution of PCMs,temporal evolution of the melting front, and temperature variations of measurement points in both tanks were compared. The average temperature and energy storage of PCMs were calculated to evaluate the thermal performance of different configurations. The results indicate that compared to cylinder B(with a straight tube), the energy storage in cylinder A(with a spiral tube)increased by 78.8%, 38.5%, and 19.6% at Stefan numbers of 1.08, 1.28, and 1.48, respectively. Moreover, the increase in the Stefan number simultaneously ascended the average temperature and energy storage of PCMs in containers A and B, causing the shortening of the melting time. When the Stefan number was increased from 1.28 to 1.48, the storage capacity was raised from3233.18 to 3463.8 k j, and the total melting time was decreased by 34.2% from 547.5 to 360 min after the PCM was loaded in cylinder A. The research results lay a certain foundation for a deeper study of enhanced heat transfer in spiral tubes.

关键词： thermal energy storage visualization experiment PCM spiral tube straight tube

AND molecular logic gates based on host-guest complexation operational in live cells

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第2期33卷 881-884页

作者： Siyang jiang Weipeng mao Dake mao Zhan-Ting Li Da Ma Department of Chemistry Fudan UniversityShanghaiShanghai 200433China College of Chemistry and Green Catalysis CenterZhengzhou UniversityZhengzhou 450001China

We report supramolecular AND logic gates based on host-guest complexation between acid-labile acyclic cucurbit[n]uril(CB[n]) molecular container and Na Cl O-responsive dye. Supramolecular AND logic gate is turned on due to acid-triggered degradation of molecular container and the release of the dye, followed by Na Cl O-induced fluorescence “switch on” effect of the dye. The reason for AND molecular logic gate is discovered to be the combination of oxidation inhibition and fluorescence “switch off” effect. Supramolecular AND logic gate is confirmed to be operational in live MCF-7 and He La cancer cells.

关键词： Host-guest chemistry Logic gate Stimuli-responsive systems Cucurbituril Bioimaging