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A Discrete Singular Integral Operator(In Memory of Professor Long Ruilin)

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Acta Mathematica Sinica,English Series 1998年第2期14卷 235-244页

作者： Fan Dashan (department of Mathematical Sciences,University of Wisconsin-Milwaukee,Milwaukee,WI 532.1,USA)(Email:fan@alpha1.csd.uwm.edu)lu Shanzhen (department of mathematics,beijing normal University,beijing 100875,china)(Email:lusz@***)Pan Yibiao (department of mathematics and Statistics,University of Pittsburgh,Pittsburgh,PA 152.0,USA)(Email:yibiao@tomato.math.pitt.edu) University of Wisconsin-Milwaukee 美国北京师范大学数学系北京 Pittsburgh大学美国

Suppose that {αk}k∞=-∞ is a Lacunary sequence of positive numbers satisfying infαk+1/αk=α>1 and that Ω（y’）is a function in the Besov space B10,1(Sn-1)where Sn-1 is the unit sphere on Rn（n≥2..We prove that if ∫Sn-1Ω（y’）dσ（y’）=0 then the discrete singular integral operator TΩf（x）=∫(Sn-1)f（x-αky’）Ω（y’）dσ（y’） and the associated maximal operator TΩf（x）=∫Sn-1f（x-αky’）Ω（y’）dσ（y’） are both bounded in the space L2./sup>（Rn）. The theorems in this paper improve a result by Duoandikoetxea and Rubio de Francia in the L2./sup> case.

关键词： Singular integral Besov space Rough kernel

Variable Stars in the 50BiN Open Cluster Survey.Ⅲ.NGC 884

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Research in Astronomy and Astrophysics 2024年第2期24卷 36-45页

作者： Lin-Hong Wang Qian-Heng Nie Kun Wang Xiao-Dian Chen Chun-Guang Zhang Li-Cai Deng Xiao-Bin Zhang Tian-lu Chen department of Physics College of ScienceTibet UniversityLhasa 850000China Key Laboratory of Cosmic Rays Tibet UniversityMinistry of EducationLhasa 850000China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Middlesex School ConcordMassachusettsUnited States of America School of Physics and Astronomy China West Normal UniversityNanchong 637002China

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky *** stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host *** most powerful tool for such studies is time-domain photometric *** paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC *** target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally *** the observation run in 2.16 November,a total of 92.7 B-band CCD images and 82.8Ⅴ-band CCD images were *** detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown *** new variable stars were discovered in this *** also compared the variable star content of NGC 884 with its companion NGC 869.

关键词： stars variables general-(Galaxy:)open clusters and associations individual(…,…)-(stars:)binaries general

A discussion on the anomalous threshold enhancement of J/ψ–ψ(3770)couplings and X(6900)peak

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Chinese Physics C 2024年第4期48卷 1-5页

作者：陆业陈畅秦广友郑汉青 Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics(MOE) Central China Normal UniversityWuhan 430079China department of Physics Peking UniversityBeijing 100871China College of Physics Sichuan UniversityChengdu 610065China

The attractive interaction between J/ψandψ(3770)has to be strong enough if X(6900)is of the molecule *** argue that sinceψ(3770)decays predominantly into a DD^(¯)pair,the interactions between J/ψandψ(3770)may be significantly enhanced owing to the three point DD^(¯)loop *** enhancement originates from the anomalous threshold located at t=−1.2.8 GeV^(2.,whose effect propagates into the s-channel partial wave amplitude in the vicinity of √s≃6.94 *** effect may be helpful in the formation of the X(6900)peak.

关键词： exotic hadrons hadron molecule X(6900)

Approaches and countermeasures of the transfer of rural surplus labors in china

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Journal of Geographical Sciences 2000年第1期10卷 66-71页

作者： DENG Xiang-zheng, GUO Huan-cheng, lu Qi, SONG Jin-ping (Institute of Geography, Chinese Academy of Sciences, beijing 100101, {2. of Resourses and Environmental Sciences, beijing normal University, beijing 100101 china)

The transfer of rural surplus labors concerns the development of agriculture and the national economy in china. On the pivotal period of transforming economy and society, whether the transfer can be accomplished successfully will play an important role in the social stabilization and the sustainable development of economy. In this paper, the authors bring out the characteristics and the main impediment of transfer. At the same time, countermeasures which are more effective have been put forward.

关键词： rural surplus labors transfer,china

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一类中立型泛函微分方程周期解问题

数学年刊（A辑） 2004年第5期20卷 645-652页

作者：鲁世平葛渭高郑祖庥安徽师范大学数学系安徽芜湖241000 北京理工大学数学系北京100081 安徽大学数学系合肥230039

本文利用Fourier级数理论和Mawhin重合度拓展定理研究一类中立型泛函微分方程的周期解存在性问题.在其对应的特征方程具有零特征根的条件下,得到了周期解存在性的新结果.

关键词：中立型泛函微分方程周期解 Fourier级数特征根特征方程定理存在性问题拓展条件

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ITS中基于纠错诊断的知识表示模型

计算机工程与应用 2004年第33期40卷 212-214页

作者：冯红杨卉王陆首都师范大学北京100037

智能教学系统是以专家系统为核心,帮助学生解决问题的教学系统。传统的辅助教学系统在测试学生学习情况时,只是简单的给学生一个分数,而没有给他们提高学习表现的机会。如果对测试结果进行分析,并提出相应的建议,将更有利于学生对各知... 详细信息

智能教学系统是以专家系统为核心,帮助学生解决问题的教学系统。传统的辅助教学系统在测试学生学习情况时,只是简单的给学生一个分数,而没有给他们提高学习表现的机会。如果对测试结果进行分析,并提出相应的建议,将更有利于学生对各知识点的学习。文章提出了一个概念图模型,并将它应用在一个基于测试与诊断的ITS系统中,通过分析学科知识和测试结果来向学生提供学习建议,从而进一步提高学生成绩。最后,我们对该模型的性能给出了一个初步的结论。

关键词：智能教学系统诊断模型概念图

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多目标的学习者模型研究

计算机工程与应用 2003年第36期39卷 98-100页

作者：冯红王陆杨卉首都师范大学教育技术系北京100037

建立学习者模型几乎是所有ITS系统的普遍任务,当前的软件系统趋向于转入分布式和多代理系统,学习者模型转向零散的、由各种软件代理在特定环境下产生的模型。在“个性化课件生成子系统”中运用了这一思想,建立了基于多目标的、运行于分... 详细信息

建立学习者模型几乎是所有ITS系统的普遍任务,当前的软件系统趋向于转入分布式和多代理系统,学习者模型转向零散的、由各种软件代理在特定环境下产生的模型。在“个性化课件生成子系统”中运用了这一思想,建立了基于多目标的、运行于分布式与多代理系统之上的学习者模型,该文将主要介绍这一系统的基本构成与运行结构、系统中目标的定义与组织结构,并对目标的解释、目标的生存周期等问题做了进一步的探讨。

关键词：智能教学系统学习者模型软件系统软件代理学生模型