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Converse Result on Szász-Type Operators

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Transactions of tianjin University 2010年第2期16卷 135-137页

作者：宋占杰 School of Sciences Tianjin University Institute of TV and Image Information Tianjin University

Szász-type operators can be constructed by a Poisson process. The purpose of this paper is to derive the converse result in connection with Szász-type operators by Steckin-Marchaud-type inequalities and new Ditzian ... 详细信息

关键词： Szász型算子 Ditzian模逆向泊松过程连续性不等式

Research on analysis method for temperature control information of high arch dam construction

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Science china(Technological Sciences) 2011年第S1期54卷 40-46页

作者： ZHONG DengHua,ZHAO ChenSheng & REN BingYu Department of Hydraulic and Hydroelectric Engineering,School of Civil Engineering,tianjin University,tianjin 300072,china Department of Hydraulic and Hydroelectric Engineering School of Civil Engineering Tianjin University Tianjin China

Temperature control,which is directly responsible for the project quality and progress,plays an important role in high arch dam *** to discover the rules from a large amount of temperature control information collected in order to guide the adjustment of temperature control measures to prevent cracks on site is the key scientific *** this paper,a mathematic logical model was built firstly by means of a coupling analysis of temperature control system decomposition and coordination for high arch ***,an analysis method for temperature control information was presented based on data mining ***,the data warehouse of temperature control was designed,and the artificial neural network forecasting model for the highest temperature of concrete was also ***,these methods were applied to a practical project. The result showed that the efficiency and precision of temperature control was improved,and rationality and scientificity of management and decision-making were *** of these researches provided an advanced analysis method for temperature control in the high arch dam construction process.

关键词： high arch dam construction temperature control information data mining data warehouse neural network model

A survey of fishes distribution and reproduction in Beitang Estuary

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Acta Oceanologica Sinica 1989年第2期8卷 293-305页

作者： Li Mingde Department of Biology, Nankai University, tianjin, china Dept. of Biology Nankai Univ. Tianjin China China

As a summary of the finding from the investigation of fishes in Beitang Estuary,tianjin,the paper deals with the young fishes 'biomass, composition and change, and studies the spawning habit, spawning time, fecundity,... 详细信息

关键词： A survey of fishes distribution and reproduction in Beitang Estuary

From discrete [Mn_4] cluster to 1D complex: Two new mixed-valence manganese complexes with slow magnetization relaxation

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Science china Chemistry 2009年第9期52卷 1463-1469页

作者： YANG PeiPei & LI LiCun Department of Chemistry, Nankai University, tianjin 300071, china Department of Chemistry Nankai University Tianjin China

A tetranuclear manganese complex [Mn4(HL)4(MeOH)4(SCN)2]·3MeOH (1) and a one-dimensional assembly of [Mn4] units, [Mn4(HL)4(MeOH)4(N(CN)2)2]·2.5MeOH (2) (H3L = 2,6-bis(hydroxymethyl)-4-methyl-phenol), have been synthesized and studied. Complexes 1 and 2 crystallize in the triclinic space group P 1and monoclinic space group P21/n, respectively. Complex 1 possesses a mixed-valence tetranuclear dicubane unit, which comprises two MnⅡ and two MnⅢ ions. Complex 2 is built from the similar tetranuclear [Mn4] units connected through two N(CN)2-anions into a 1-D chain. The temperature dependence of the magnetic susceptibilities of 1 and 2 indicates ferromagnetic interactions between the manganese ions. Frequency-dependent out-of-phase signals of alternating current magnetic susceptibilities are observed in the low temperature range for both complexes, indicating a slow magnetic relaxation.

关键词： tetranuclear manganese complex 1D complex magnetic properties slow magnetic relaxation

Gymnosperms on the eve of the terminal Permian mass extinction in North china and their survival strategies

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Chinese Science Bulletin 1998年第11期43卷 889-897页

作者： WANG Ziqiang+1 and ZHANG Zhiping+2, 1. tianjin Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, tianjin 300170, china 2. tianjin Centre of Physical and Chemical Techniques, tianjin 300050, china tianjin Institute of Geology and Mineral Resources Chinese Academy of Geological Sciences Tianjin China tianjin Centre of Phyhical and Chemical Techniques Tianjin China

Main characteristics of the Permian redbed gymnosperms in North china have been summarized: dominant peltasperms and conifers, numerous enigmatics such as Gigantonoclea and Psygmophyllum, and abundant precursors of Mesozoic gymnosperms. Furthermore, stresses affecting these plants survival are suggested to be paleoatmospheric CO-2 concentration, water stress, wind and fire activities, and fungal infection. Consequently, a preliminary analysis accounts for the ecological strategies of these gymnosperms to the P-Tr event.

关键词： North china Permian gymnosperms mass extinction.

中国科技核心期刊(中国科技论文统计源期刊)收录证书

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天津医药 2024年第7期 785-785页

作者： Institute of Scientific and Technical Information of china 中国科学技术信息研究所

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ON THE BOUNDEDNESS OF SPHERES IN F-SPACES

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Acta Mathematica Scientia 2002年第4期22卷 500-506页

作者：定光桂 Nankai University Tianjin 300071 China

In this paper, some results concerning the relationship between the bounded-ness of some spheres and the local boundedness of the .F*-space are presented. Moreover, some results about the compactness are also given.

关键词： F*-space sphere local boundedness compactness

Properties of a family of merit functions and a merit function method for the NCP

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Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 379-390页

作者： LU Li-yong HUANG Zheng-hai HU Sheng-long Department of Mathematics, School of Science, tianjin University, tianjin 300072, china Department of Mathematics School of Science Tianjin University Tianjin China

A family of merit functions are proposed, which are the generalization of several existing merit functions. A number of favorable properties of the proposed merit functions are established. By using these properties, a merit function method for solving nonlinear complementarity problem is investigated, and the global convergence of the proposed algorithm is proved under some standard assumptions. Some preliminary numerical results are given.

关键词： Nonlinear complementarity problem NCP-function merit function merit function method.

NUMERICAL SIMULATIONS OF THE HYDRAULIC CHARACTERISTICS OF SIDE INLET/OUTLETS

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Journal of Hydrodynamics 2011年第1期23卷 48-54页

作者： YE Fei GAO Xue-ping North china University of Water Conservancy and Electric Power Zhengzhou 450011 China School of Civil Engineering Tianjin University Tianjin 300072 China

The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and *** on the physical model test,the realizable k-εturbulence model is used in the 3-D simulation of the side inlet/outlet.A new scheme is suggested to obtain the uneven flow distribution over three branch *** variation of the free surface with the reservoir water level under the pumped condition is simulated,with results consistent with the experimental results.

关键词： hydraulic characteristics side inlet/outlet pumped storage plant numerical simulation realizable k-εturbulence model