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Synthesis and spectroscopic characterization of fluorescent solid rare-earth complexes with hydroxamic acids

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Rare Metals 2002年第3期21卷 163-169页

作者： LI Yangsheng and LI FanFaculty of Chemistry and Materials Science, nanchang University, nanchang 200437, china Faculty of Chemistry and Materials Science Nanchang University Nanchang 330047

The complexes RE_2(DHYA)_3 centre dot nH_2O in the title bar were synthesizedthrough some reactions of trivalent rare-earth ions. In the process of synthesis, dihydroxamicacids were taken as ligands while the alcohol was taken as a solvent. The ligands includedadipylhydroxamic acid (ADHA), p-phthalichydroxamic acid (PPHA), oxalohydroxamic acid (OXHA),butadihydroxamic acid (BDHA), o-phthalichydroxamic acid (OPHA), benzoylhydroxamic acid (BHA), *** at 25 deg C, the molar conductances in various modes are 13.00-21.05 S centre dot cm^2centre dot mol^(-1), which shows that rare-earth complexes are nonelectrolytes and the hydroxaminogroups of the complexes have taken part in bonding. Infrared spectra, ultraviolet spectra, nuclearmagnetic resonance (~1HNMR) spectra, and fluorescence spectra were used to investigate thecomplexes. Experiments have proved that the complexes of En^(3+)and Tb^(3+) with aromatic hydroxamicacids have good fluorescent characteristics.

关键词： hydroxamic acid complex rare earth

Optimized third-order force-gradient symplectic algorithms

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1600-1609页

作者： LI Rong & WU Xin School of Science,nanchang University,nanchang 330031,china School of Science Nanchang University Nanchang China

With the natural splitting of a Hamiltonian system into kinetic energy and potential energy,we construct two new optimal thirdorder force-gradient symplectic algorithms in each of which the norm of fourth-order truncation errors is *** are both not explicitly superior to their no-optimal counterparts in the numerical stability and the topology structure-preserving,but they are in the accuracy of energy on classical problems and in one of the energy eigenvalues for one-dimensional time-independent Schrdinger *** particular,they are much better than the optimal third-order non-gradient symplectic *** also have an advantage over the fourth-order non-gradient symplectic integrator.

关键词： symplectic integrators symplectic scheme-shooting method celestial mechanics time-independent Schrdinger equation energy eigenvalues numerical stability bisection method topological structure

ON THE THEOREM OF ARROW-BARANKIN-BLACKWELL FOR WEAKIY COMPACT CONVEX SET

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Chinese Annals of Mathematics,Series B 1994年第2期15卷 173-180页

作者： FU WANTAO(Department of Matehematics,nanchang University, nanchang 330047, Jiangxi, china) 南昌大学数学系江西南昌 330047

This paper studies the known density theorem of Arrow- Barankin-Blackwell. T he following main result is obtained: If X is a Hausdorff locally convex topological space and C X is a closed convex cone with bounded base, then for every nonempty weakly compact convex subset A, the set of positive proper efficient points of A is dense in the set of efficient points of A.

关键词： Positive proper efficient point Efficient point Convex cone Hausdorff space.

智能时代深度学习教学法的核心要义与行动框架

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电化教育研究 2024年第5期45卷 5-12页

作者：杨南昌梁慧芳江西师范大学教育研究院江西南昌330022 江西师范大学教育学院江西南昌330022

智能时代的教学范式面临从“消费模式”向“生成模式”转型的挑战。促进教学范式成功转型的关键在于深度学习方式的变革,并通过重构深度学习教学法实现“化知识为素养”。在考察国际典型深度学习项目的基础上,归结出深度学习教学法的七... 详细信息

智能时代的教学范式面临从“消费模式”向“生成模式”转型的挑战。促进教学范式成功转型的关键在于深度学习方式的变革,并通过重构深度学习教学法实现“化知识为素养”。在考察国际典型深度学习项目的基础上,归结出深度学习教学法的七大关键特征以及从理解世界、参与世界到改变世界进阶转换的设计要义,并构建了“课堂—学校”系统联动变革课堂的行动框架。深度学习没有固定模式,而现实教学情境又复杂多元。研究认为,为一线教师提供一种由“核心要义+行动框架”组成的、更具情境指导力量的“解释性教学法框架”,将更有助于他们超越具体教学模式的应用局限,有效推动深度学习的实践落地,并更有可能创建更多富有成效且个性多彩的深度学习课堂。

关键词：智能时代深度学习教学法范式转型核心要义行动框架

New concurrent digital signature scheme based on the computational Diffie-Hellman problem

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The Journal of china Universities of Posts and Telecommunications 2010年第6期17卷 89-94,100页

作者： QIN Wen,ZHOU Nan-run Department of Electronic Information Engineering,nanchang University,nanchang 330031,china Department of Electronic Information Engineering Nanchang University Nanchang 330031 China

Based on strong designated verifiers signatures,a new fair concurrent signature scheme is proposed. Compared with the previous concurrent signature schemes,even if a keystone must be chosen by the initial signer,the matching signer will easily get the keystone through an extraction algorithm. Due to the property of strong designate verifying,the initial signer couldn＇t make use of the keystone prepared carefully to deceive the matching signer. Then the matching signer is able to participate actively the signature scheme. Besides,there aren＇t bilinear operations in the keystone algorithm to deliver the keystone efficiently. Therefore the efficiency of our signature scheme is also improved.

关键词： designated verifiers signature fairness concurrent signature information security

Microstructure modification by La_2O_3 and its effect on wear resistance properties of as-cast ZL107 alloy

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Rare Metals 2010年第5期29卷 460-464页

作者： WAN Diqing Key Laboratory of the Ministry of Education of china for Conveyance and Equipment,East china Jiaotong University,nanchang 330013,china Key Laboratory of the Ministry of Education of china for Conveyance and Equipment East China Jiaotong University Nanchang China

Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL 107 has been compared. The wear resistance of as-cast ZL 107 aluminum alloy can be significantly improved after modification.

关键词： aluminum alloys lanthanum oxides modification microstructure wear resistance

A SECOND-ORDER MOMENT TURBULENCE MODEL FOR POWER LAW FLUID WITH PARTICLES

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Journal of Hydrodynamics 2007年第5期19卷 607-612页

作者： ZENG Zhuo-xiong PAN Yang ZHONG Chun QIU Guo-bin Aeronautic and Mechanical Engineering College Nanchang Hangkong University Nanchang 330063 China School of Civil Engineering and Architecture East China Jiaotong University Nanchang 330013 China

The USM-θ model of power law fluid for dense two-phase turbulent flow was developed, which combines the unified second-order moment model for two-phase turbulence with the particle kinetic theory for the inter-particle collision. This model was used to simulate the turbulent flow of power law fluid single-phase in pipe. It is shown that the USM- θ model has better prediction result than the κf -κf - κ- εp -θ model. The USM-O model was then used to simulate the dense two-phase turbulent up flow of power law fluid with particles. With the increase of the flow exponent, the velocities of power law fluid and particles increase near the pipe centre. Comparison between the two-phase flow of power law fluid-particle and of liquid-particle indicates that the axial fluctuation velocity of fluid phase and particle phase in liquid-particle two-phase flow is smaller than that in the power law fluid two-phase flow, but the two-phase velocities of power law fluid-particle and liquid-particle are close to each other.

关键词： power law fluid two-phase flow second-ordermoment turbulence model

PRE-IMAGE ENTROPY OF NONAUTONOMOUS DYNAMICAL SYSTEMS

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Journal of Systems Science & Complexity 2008年第3期21卷 441-445页

作者： Xianjiu HUANG Xi WEN Fanping ZENG Department of Mathematics Nanchang University Nanchang 330031 China Department of Computer Nanchang University Nanchang 330031 China Department of Mathematics Liuzhou Theachers College Liuzhou 545004 China

The authors define and study topological pre-image entropy for the non-autonomous discrete dynamical systems given by a sequence {fi}i=1^∞ of continuous self-maps of a compact topological space. The basic properties and the invariant with respect to equiconjugacy of pre-image entropy for the non-autonomous discrete dynamical systems are obtained.

关键词： Equiconjugacy non-autonomous pre-image entropy sequence of continuous self-maps

CONTACT FRICTION ANALYSIS AND STRESS OSCILLATION SUPPRESSION WITH A SIMPLE INTERFACE ELEMENT

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Acta Mechanica Solida Sinica 2000年第1期13卷 33-41页

作者： Lei Xiaoyan (Department of Civil Engineering,East china Jiaotong University,nanchang 330013,china) Department of Civil Engineering East China Jiaotong University Nanchang 330013 China

A simple interface element for analyzing contact friction problems is developed. Taking nodal displacements and contact stresses as unknowns, this element can simulate frictional slippage, decoupling and re-bonding of two bodies initially mating or having gaps at a common interface. The method is based on the Finite Element Method and load incremental theory. The geometric and static constraint conditions on contact surfaces are treated as additional conditions and are included in stiffness equations. This simple element has the advantages of easy implementation into standard finite element programs and fast speed for convergence as well as high accuracy for stress distribution in interface. Undesirable stress oscillations are also investigated whenever large stress gradients exist over the contact surfaces. Exact integration or the conventional Gauss integration scheme used to evaluate the interpolation function matrix of the interface element is found to be the source of the oscillations. Eigenmode analysis demonstrates that the stress behavior of an interface element can be improved by using the Newton-Cotes integration scheme. Finally, the test example of a strip footing problem is presented.

关键词： contact friction interface element stress oscillation eigenmode analysis