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The α-orthogonal complements of regular Dirichlet subspaces for one-dimensional Brownian motion

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Science China Mathematics 2016年第10期59卷 2019-2026页

作者： li li ping SONG XiuCui School of Mathematical Sciences Fudan University

Roughly speaking a regular Dirichlet subspace of a Dirichlet form is a subspace which is also a regular Dirichlet form on the same state space. In particular, the domain of regular Dirichlet subspace is a closed subspace of the Hilbert space induced by the domain and a-inner product of original Dirichlet form. We investigate the orthogonal complement of regular Dirichlet subspace for one-dimensional Brownian motion in this paper. Our main results indicate that this orthogonal complement has a very close connection with the a-harmonic equation under Neumann type condition.

关键词： Dirichlet form regular Dirichlet subspace harmonic equation Neumann type condition

Sub-channel interference cancellation in SVD-based MIMO system

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 34-37页

作者： WU ping li li-hua ZHANG ping Beijing University of Posts and Telecommunications Beijing 100876 China

For singular value decomposition （SVD）-based multiple input multiple output （MIMO） systems, implicit channel state information （CSI） incurs interferences amongst sub-channels if the CSI at the transmitter is not explicit. An improved SVD-based MIMO which can fully cancel the inter sub-channel interferences by reconstructing the transmitter- receiver system matrix on interferences analysis is provided. Simulation results indicate that the proposed algorithm outperforms the traditional SVD-based MIMO in a large degree.

关键词： MIMO systems SVD interference cancellation (IC) CSI feedback

Unitary space vector quantization codebook design for spatial correlated limited feedback MIMO system

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 23-27页

作者： WU ping li li-hua Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Ministry of Education Wireless Technology Innovation Institute (WTI) Beijing I00876 China

In the transmitting, beamforming, and receiving combing （TBRC） MIMO system, a codebook based feedback strategy is usually used to provide the transmitter with the beamforming vector. The adopted codebook affects the system performance considerably. Therefore, the codebook design is a key technology in the TBRC MIMO system. In this article, the unitary space vector quantization （USVQ） codebook design criterion is proposed to design optimal codebooks for various spatial correlated MIMO channels. And the unitary space K-mean （USK） codebook generating algorithm is provided to generate the USVQ codebooks. Simulations show that the capacities of the feedback based TBRC systems using USVQ codebooks are very close to those of the ideal cases.

关键词： USVQ multiple-input multiple-output (MIMO) system TBRC

Completeness of Induced Cotorsion Pairs in Representation Categories of Rooted Quivers

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Acta Mathematica Sinica,English Series 2024年第10期40卷 2436-2452页

作者： Zhen Xing DI li ping li li liANG Fei XU School of Mathematical Sciences Huaqiao UniversityQuanzhou 362021P.R.China LCSM(Ministry of Education) School of Mathematics and StatisticsHunan Normal UniversityChangsha 410081P.R.China Department of Mathematics Lanzhou Jiaotong UniversityLanzhou 730070P.R.China Gansu Provincial Research Center for Basic Disciplines of Mathematics and Statistics Lanzhou 730070P.R.China Department of Mathematics Shantou UniversityShantou 515063P.R.China

This paper focuses on a question raised by Holm and Jorgensen,who asked if the induced cotorsion pairs(Φ(X),Φ(X)^(⊥))and(^(⊥)Ψ(Y),Ψ(Y))in Rep(Q,A)—the category of all A-valued representations of a quiver Q—are complete whenever(X,Y)is a complete cotorsion pair in an abelian category A satisfying some mild *** give an affirmative answer if the quiver Q is *** an application,we show under certain mild conditions that if a subcategory L,which is not necessarily closed under direct summands,of A is special precovering(resp.,preenveloping),thenΦ(L)(resp.,Ψ(L))is special precovering(resp.,preenveloping)in Rep(Q,A).

关键词： Rooted quiver complete cotorsion pair special precovering(preenveloping)subcategory

Sensitivity optimization of a monolithic high-shock three-axis piezoresistive accelerometer with single sensing element

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Chinese Science Bulletin 2009年第19期54卷 3600-3607页

作者： SONG ping li QingZhou li KeJie School of Aerospace Science and Engineering Beijing Institute of Technology Beijing 100081 China

There exist several difficulties in the design of monolithic high-shock three-axis accelerometer, such as high g overload, transverse overload and the cross coupling in three dimensions, etc. It is necessary to optimize the sensitivity to improve the performance of the accelerometer. For the monolithic high-shock three-axis accelerometer, the complexity of the sensitivity optimization is that it should consider not only the sensitivity difference between different axes but also the elimination of cross-coupling outputs, together with the natural frequency, structural integrity and high g overload. In this paper, the optimization process for decreasing the difference of the sensitivities between different axes of a monolithic high-shock three-axis piezoresistive accelerometer with single sensing element is established. The optimization is conducted in the condition of 100000 g acceleration by two methods-the method based on the optimization module of ANSYS and the ACO (ant colony optimization) method. The comparison between un-optimized and optimized models proves the efficiency of the optimization methods. In addition, the optimization results show that the ACO method combined with the FEA (finite element analysis) is much more efficient than the method based on the optimization module of ANSYS for the structural optimization problem. And the ACO method can be widely used in the optimization problem of the sensing elements with complicated structure.

关键词：单片电路最佳化设计研究 ACO

Relativistic Configuration Interaction Calculations on Kα X-Ray Satellites of Manganese

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Communications in Theoretical Physics 2008年第1期49卷 217-220页

作者： li Hui-li li ping CHENG Zhang MA Hai-Rong Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

With contributions from Breit interaction, quantum electrodynarnics （QED） corrections and nuclear mass corrections to the initial and final levels are taken into account. The transition energies, transition probabilities, and absorption oscillator strengths of Kα x-ray from Mn XVII to Mn XXIV have been calculated by using relativistic configuration interaction （RCI） and multi-configuration Dirac Fock （MCDF） method in the active interaction approach. Compared with the only available experimental transition data on He-like and li-like manganese, the present results are in good agreement with them, and the rest of transition data of the present results are new ones. These wide range data can provide useful parameters for the study of the manganese plasma.

关键词： transition highly ionized Mn relativistic configuration interaction multi-configuration DiracFock method

A New Ti^(3+)-assisted Synthesis of Pd-supported TiO_2 Nanomaterial with Enhanced Photocatalytic Activity for Hydrogen Generation and Methyl Orange Degradation

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Chinese Journal of Structural Chemistry 2015年第8期34卷 1203-1216页

作者： WANG Ya-Fang li li-ping HUANG Xin-Song li Guang-She School of Chemistry and Chemical Engineering Inner Mongolia University State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Owing to the merits of high catalytic activity, Pd-supported materials have received extensive attention. However, those materials always require complex and high-cost synthetic processes such as high-temperature calcination or 1-12 reduction, which seriously hinder their wide applications. In this work, a novel Pd reduction method was developed for Pd-supported TiO2 catalysts, in which the Pd2~ ions were partly reduced and homogeneously loaded on the surface of 8 nm TiO2 with the assistance of pre-produced surface Ti3＋ ions. This facile preparation is calcination-free and cost-low. The excellent catalysts can produce H2 33 mmol/g/h under UV-vis light irradiation, and degrade nearly 10% methyl orange in 1 h visible-light irradiation, which is much higher than that of unloaded TiO2 or Pd/TiO2 prepared by traditional high-temperature calcination methods. Moreover, the resulting Pd-supported TiO2 nano-catalysts are also effective for colorless phenol degradation under visible-light. The reasons for these superior activities can be assigned to the co-existence of Pd~ and Pd2~ on the surface of TiO2 nanoparticles, which is closely related to the calcination-free synthetic process. UV-Vis absorbance spectra show that the obtained 0.53Pd/TiO2 is visible-light-driven and nitrogen physisorption isotherms indicate a high specific surface area of 203 m2/g. The preparation method reported herein may provide hints for obtaining other high photocatalytic activity Pd-based supported catalysts for hydrogen generation and methylene orange degradation.

关键词： Pd-supported, TiOz, Ti3+, photocatalysis

Electrochemical behavior of different shelled microcapsule composite copper coatings

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International Journal of Minerals,Metallurgy and Materials 2011年第3期18卷 377-384页

作者： Xiu-qing Xu Yan-hong Guo Wei-ping li li-qun Zhu School of Materials Science and Engineering Beihang University Beijing 100191 China

Copper/liquid microcapsule composite coatings with polyvinyl alcohol （PVA）, gelatin or methyl cellulose （MC） as shell materials were prepared by electrodeposition. The influence of shell materials on the corrosion resistance of the composite coatings in 0.1 M H2SO4 was investigated by means of electrochemical techniques, scanning electron microscopy （SEM）, and energy dispersion spectrometry （EDS）. The results show that the participation of microcapsules can enhance the corrosion resistance of the composite coatings compared with the traditional copper layer. Based on the analysis of electrochemical test results, the release ways of microcapsules were deduced. Gelatin and MC as the shell materials of microcapsules are easy to release quickly in the composite coating. On the contrary, the releasing speed of PVA microcapsules is relatively slow due to their characteristics.

关键词： composite coatings shell materials copper microcapsules electrochemical properties corrosion resistance electrodeposition

Design, Syntheses and Biological Activities of Novel Anthranilic Diamide Insecticides Containing N-Pyridylpyrazole

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Chemical Research in Chinese Universities 2013年第1期29卷 51-56页

作者： ZHAO Yu li Yong-qiang XIONG li-xia XU li-ping PENG li-na li Fang li Zheng-ming National Pesticidal Engineering Centre(Tianjin) State Key Laboratory of Elemento-organic Chemistry Nankai University Tianjin 300071 P. R. China

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamide derivatives containing N-pyridylpyrazole was designed and synthesized. All the compounds were characterized by H NMR spectroscopy and elemental analysis. The single crystal structure of com pound 8j was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results show that some compounds exhibited moderate insecticidal activities against Lepidoptera pests. Among this series of compounds, compounds 80 and 8p showed 100% larvicidal activity against Mythimna separate Walker, Plutella xylostella linnaeus and Laphygma exigua Hubner at a test concentration of 200 mg/kg, which is equal to the commercial chlorantraniliprole.

关键词： Anthranilic diamide Ryanodine receptor Insecticidal activity