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Study on Potassium Fluoaluminate Eutectic Flux

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Transactions of tianjin University 2004年第3期10卷 184-186页

作者：张韻慧尹淑梅肖莉李宁张则甡 College of Pharmaceuticals and Biotechnology Tianjin University Tianjin 300072 China School of Materials Science and Engineering Tianjin University Tianjin 300072 China tianjin Welding Research Institute Tianjin 300110 China

In this study, Nocolok eutectic flux,used widely in the process of the brazing of aluminum and its alloy, was prepared by the reaction between Al(OH) 3.KOH resolution and HF. A series of KF-AlF 3.eutectic productions at various reaction temperatures were prepared. The melting points of the products were measured by differential thermal analysis (DTA), and the composites were characterized by X-ray diffraction (XRD). The results suggest that the temperature control is important to produce an ideal flux consisting of K 2AlF 5, H 2O and KAlF 4, with a low melting point of 560 ℃,which is suitable for the brazing of aluminum and its alloy as the aluminum fluxes.

关键词： potassium fluoaluminate eutectic flux differential thermal analysis X-ray diffraction

Clustering behavior of solid particles in two-dimensional liquid-solid fluidized-beds

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Particuology 2007年第5期5卷 305-311页

作者： Xiaodong Ana, Mingyan Liua,b,, Yunguan Fua a School of Chemical Engineering and Technology, tianjin University, tianjin 3.0072, china b State Key Laboratory of Chemical Engineering, tianjin University, tianjin 3.0072, china [a]School of Chemical Engineering and Technology tianjin University tianjin 3.0072 china [b]State Key Laboratory of Chemical Engineering tianjin University tianjin 3.0072 china

In this paper, the clustering behavior of solid particles in a two-dimensional (2D) liquid-solid fluidized-bed was studied by using the charge coupled devices (CCD) imaging measuring and processing technique and was characterized by fractal analysis. CCD images show that the distribution of solid particles in the 2D liquid-solid fluidised-bed is not uniform and self-organization behavior of solid particles was observed under the present experimental conditions. The solid particles move up in the 2D fluidized-bed in groups or clusters whose configurations are often in the form of horizontal strands. The box fractal dimension of the cluster images in the 2D liquid-solid fluidized-bed increases with the rising of solid holdup and reduces with the increment of solid particle diameter and superficial liquid velocity. At given solid holdup and solid particle size, the lighter particles show smaller fractal dimensions.

关键词： CCD Liquid–solid ?uidized-bed Fractal dimension Cluster Self-organization structure

Low-temperature optical spectra and zero-phonon transition of color centers in γ-rayed lithium fluoride crystals

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Chinese Journal of Lasers 1993年第5期B2卷 59-63页

作者： Honggen Gu (Department of Physics, tianjin University, tianjin 3.0072,china) tianjin Univ Tianjin China

The zero-phonon lines on R2, R~+, N1and R′2centers and some new narrow lines have been observed in bivalent-metal-doped and air-grown LiF crystals irradiated by γ-ray in the temperature range of 9.5—13.K. The spect... 详细信息

关键词： low-temperature spectra zero-phonon transition color-centers in LiF2

The　characteristic　and　prediction　of　scour　in　front　of　breakwaters　by　standing　waves

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Acta Oceanologica Sinica 1995年第1期14卷 103-112页

作者： Gao Xueping(Deptartment of Water resources and Harbor Engineering, tianjin University, tianjin 3.0072,{3.) Deptartment of Water resources and Harbor Engineering Tianjin University Tianjin 300072 China

In this paper bottom scours in front of vertical breakwaters by standing waves are systematically investigated, the scouring patterns, criterion for differentiating the scouring patterns and scouring mechanism are discussed ; a formula of maximum depth of scouring trough considering sediment size is given; and influence of mound foundation on bottom scours is investigated.

关键词： Standing waves scours

Archaean Greenstone Belts in china

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Acta Geologica Sinica(English Edition) 1994年第1期68卷 15-29页

作者： Shen Baofeng, Peng Xiaoliang, Luo Hui and Mao Debaotianjin Institute of Geology, Ministry of Geology and mineral resources, tianjin tianjin Institute of Geology Ministry of Geology and Mineral Resources Tianjin 1Other participants in the study include Jin Wenshan Hu Xiaodie Li Shuangbao and Li Junjian.

Chinese Achaean greenstone belts are mainly distributed along the northern and southwestern margins of the North china platform. In terms of their geological characteristics, the greenstone belts in china are comparable to those in other countries but at the same time have unique features of their own. In view of their geochemistry, the Chinese greenstone belts may be grouped into three types: the Jiapigou type, Qingyuan type and Xiaoqinling type. The greenstone belts were formed possibly in a rift-type palaeo-tectonic setting, similar to that of the modern island are-continental margin mobile belts.

关键词： Archaean greenstone belts types of greenstone belts rift type tectonic setting china

Raising medium function of environmental engineering by using life rubbish to produce carpet turf

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Journal of Environmental Sciences 2000年第4期12卷 498-505页

作者： DUO Li an, ZHAO Shu lan (College of Chemistry and Biology, tianjin Normal University, tianjin 3.0074, china) 天津师范大学天津 3 0 0 0 74

Abundant material with low cost was utilized to raise medium function of producing carpet turf by life rubbish. The results showed that the material used could strikingly raise water retentiveness and ventilating of medium. Through the determination of the effect of each growth index of several turfgrass, emergence density, plant height, root growth and individual plant′s net primary production were all positively related to the material′s amount mixed, showing that the mixture of material could promote turfgrass growth, further proving that the material used raised medium function of producing carpet turf by life rubbish and made most use of life rubbish resources. It provided a scientific base is for application of environmental engineering by using life rubbish to produce carpet turf. So the study had both important theoretic meaning and applied value.

关键词： life rubbish carpet turf medium function environmental engineering

OPTIMUM CONTROL TO A PARTIALLY CONTROLLED TURBOGENERATOR SHAFT TORSIONAL VIBRATION SYSTEM

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 66-68页

作者： Hao Zhiyong Gao Wenzhi School of Mechanical Engineering，tianjin University，tianjin 3.0072，china School of Mechanical Engineering Tianjin University 天津 300072

The optimal control to a partially controlled turbogenerator shaft torsionalvibration system is investigated. The principle of input feedforward control is presented to achievethe minimum of the average vibration energy in a system, and the optimal control matrix of thesystem is derived. A turbogenerator shaft system is taken as an example to simulate the optimalcontrol process of the torsional vibration. Results from this simulation indicate that the vibrationcan be effectively controlled by a partial control strategy.

关键词： Optimal control Partially controlled system Torsional vibration Turbogenerator

INSTABILITY WAVES IN THE WALL REGION OF A TURBULENT BOUNDARY LAYER ON A FLAT PLATE

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Acta Mechanica Sinica 1989年第1期5卷 11-19页

作者： Zhou Heng (Department of Mechanics,tianjin University,tianjin,china) 1. Department of Mechanics Tianjin University Tianjin China

Coherent structures and the bursting phenomena in the wall region of a turbulent boundary layer play a very important role in determining the characteristics of the boundary layer. Yet the nature and the origin of the coherent structures are unclear until *** this paper, nonlinear stability calculations for the wall region of a turbulent boundary layer have been *** was found that there do exist instability waves which may be responsible for the coherent structures.

关键词： coherent structures instability wave turbulent boundary layer

Structural characteristics of the Tan-Lu fault zone in Cenozoic basins offshore the Bohai Sea

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Science china Earth Sciences 2008年第S2期51卷 20-31页

作者： QI JiaFu1,2,ZHOU XinHuai3.DENG RongJing4 & ZHANG KeXin2 1 State Key Laboratory of Petroleum Resource and Prospecting,china Petroleum University,Beijing 102249,china 2 Department of Earth Sciences,china Petroleum University,Beijing 102200,china 3.tianjin Branch of CNOOC china Limited,tianjin 3.0451,china 4 Beijing Research Center of CNOOC china Limited,Beijing100027,china china Petr Univ State Key Lab Petr Resource & Prospecting Beijing 102249 Peoples R China china Petr Univ Dept Earth Sci Beijing 102200 Peoples R China CNOOC china Ltd Tianjin Branch Tianjin 300451 Peoples R China CNOOC china Ltd Beijing Res Ctr Beijing 100027 Peoples R China

The Tan-Lu fault zone across the eastern margin of the Cenozoic basins offshore the Bohai Sea is a NNE-trending right-lateral strike-slip fault system developed in the Cenozoic basin cover. It cuts through NE-to NNE-striking major extensional faults that controlled the formation of Paleogene basins. Recent petroleum exploration indicates that Cenozoic structural activities of the Tan-Lu fault system have directly or indirectly affected oil and gas distribution offshore the Bohai Sea. As part of a deep fault zone the Tan-Lu fault zone has been activated since the Oligocene,and obviously affected the tectonic evolution of offshore Bohai basins since then. The formation of Paleogene rift basins offshore the Bohai Sea has utilized the pre-existing structural elements of the Tan-Lu fault zone that developed in the late Mesozoic.

关键词： strike-slip fault extensional structure Tan-Lu fault zone Bohaiwan basin