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Experimental and Numerical Investigations of an Ice-slurry Generator

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过程工程学报 2004年第1期4卷 1-7页

作者：洪若瑜董梁尚德义徐建生 Kawaji M dept. chem. & chem. Eng. Soochow University Suzhou Jiangsu 215006 China dept. chem. Eng. & Appl. chem. University of Toronto Toronto ON M5S 3E5 Canada

A new test facility equipped with refrigerant and brine circulation systems, and a rotating-scraper ice-slurry generator was constructed to analyze the ice-slurry flow and heat transfer accompanied by phase change in an industrial generator. The axial and transverse brine temperature and ice fraction concentration profiles in the ice generator were measured. The heat transfer efficiency lower than the average was identified in the upper half of the ice generator and its cause was determined by conducting three-dimensional numerical simulation using a commercial CFD code, FLUENT. Approaches of improving the brine-side heat transfer rates were investigated by incorporating extra mixing blades from numerical simulation.

关键词：泥浆泵计算流体力学实验研究数值模拟

Computational Fluid Dynamic Simulation of Liquid-Liquid Mixing in a Static Double-T-shaped Micromixer

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过程工程学报 2008年第6期8卷 1080-1084页

作者： Elmabruk A. MANSUR 王运东戴猷元 The State Key Lab. chem. Eng. Dept. Chem. Eng.Tsinghua University

The laminar flow structure and mixing performance of T-shaped and double-T-shaped micromixers with rectangular cross-section have been investigated using computational fluid dynamic (CFD) simulation. FLUENT software is used to evaluate the mixing efficiency. The numerical simulation results show that the presented double-T-micromixer is highly efficient over T-shaped micromixer. The performance of double-T-micromixer with and without static mixing elements (SME) is also investigated. The enhancement in mixing performance is thought to be caused by the generation of eddies and lateral velocity component when the mixture flows through these elements. Mixing efficiency as higher as 97% is reached within a mixing length of 320 μm downstream from the first T-junction with the enhancement of three SMEs.

关键词：计算方法流体动力学模拟方法液液混合双T形微混合器物理过程

Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of MnZn Ferrites

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Journal of Materials Science & Technology 1997年第6期13卷 467-470页

作者： M.M.Abou Sekkina(chem. dept., Faculty of Science, Tanta university, Tanta, Egypt)A.M.El-Sayed(Inorganic chem.stry dept., National Research Centre, Dokki, Cairo, Egypt) chem. dept. Faculty of Science Tanta University Tanta Egypt Inorganic chem.stry dept. National Research Centre Dokki Cairo Egypt

Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped MnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spinel cubic structure. The Mossbauer spectrum of the base sample indicates line broadening and overlapping due to relaxation of magnetic dipoles. The temperature dependence of DC-electrical conductivity has been discussed on the basis of electronic conduction (electron hopping) and ionic conduction mechanism.

关键词： Effects of Hyperfine and Dopant Cation Interactions on theDC-Electrical Conductivity of MnZn Ferrites

EIS STUDY ON ZINC RICH PAINTS IN 3.5% NaCl SOLUTION BY DOUBLE-CELL TEST

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Acta Metallurgica Sinica(English Letters) 2002年第3期15卷 299-306页

作者： DM. Xie, J.M. Hu, J.M. Wang and J.Q. ZhangDepartment of chem.stry, Zhejiang university, Hangzhou 310027, ChinaState Key Laboratory for Corrosion and Protection of Metals, Institute of Metal Research, The Chinese Academy of Sciences, Shenyang 110016, China dept. of chem. Zhejiang Univ. Hangzhou 310027 China

This paper discussed the possibility of obtaining electrochem.cal impedance spectroscopy (EIS) responses of zinc rich paints (ZRP) using serial double-cell (SDC). The influence of counter electrode was outlined. An equivalent circuit (ES) for the double-cell was then discussed. The relationship between EC, the time constant, the parameters in EC of SDC and those of two single sells was discussed. The results gained by serial double cell test are consistent with those of single cell test. It can be concluded that double cell test method can be used to study ZRP completely.

关键词： Electrodes Equivalent circuits Sodium chloride Spectroscopy Zinc

Luminescent Properties of Tetrakis (1-(2-Thenoy)-3,3,3-Trifluoracetate) Europium N-Hexadecyl Pyridinium in Modified Si-MCM-41

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Journal of Materials Science & Technology 2001年第2期17卷 290-292页

作者： Qinghong XU, Liansheng LI, Bin LI, Jihong YU and Ruren XU Key Laboratory of Inorganic Synthesis & Preparative chem.stry, Department of chem.stry, Jinn university, Changchun 130023, China dept. of chem. Jilin Univ. Changchun 130023 China

Eu(TTA)4C5H5NC16H33(TTA:1-(2-Thenoy)-3,3,3-Trifluoracetate) is encapsulated in St- MCM-41 modified with N-(3-Trimethoxysilethyl)ethylene. The emission spectrum of the assembly shows only a 5D0-7F2 transition. As compared with the rare earth complex itself, the lifetime of the assembly becomes longer and its stability under the UV radiation is much better.

关键词： MCM Europium N-Hexadecyl Pyridinium in Modified Si-MCM-41 Trifluoracetate Thenoy Si

Dielectric Properties of Some Borate Glasses

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Journal of Materials Science & Technology 2001年第2期17卷 278-282页

作者： Z.A.El-Hadi chem.stry Department, College For Girls, Ain-Shams university, Heliopolis, Cairo, Egypt dept. of chem. Coll. for Girls Ainshams Univ. Cairo Egypt

The dielectric constant, e', and the dielectric loss. e', for some selected lead borate glasses within the frequency band 105 to 107 Hz and the temperature range (20-50)'C were measured. The dielectric dispersion and the dielectric loss absorption bands were observed. the relaxation time, the activation enthalpy and entropy change of the dielectric relaxation were calculated. The results obtained were discussed and correlated to the internal network structure of the glasses studied.

关键词： rate Dielectric Properties of Some Borate Glasses

Magnetism and Its Dependence on Annealing Temperature for Sputtered Co/Cu Multilayers

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Journal of Materials Science & Technology 1998年第2期14卷 139-142页

作者： Gao, Ruwei Liu, Yihua Yan, Shishen Zhang, Deheng Zhang, Lin dept. of Physics Shandong University Jinan 250100 China

It was found that the easy magnetization axes of the films are parallel to the substrate, and the magnetic properties of both as-sputtered and annealed multilayers are isotropic in the film plane. The coercive field H//c is 4.8 kA/m and the ratio of remanence-to-saturation magnetization M//r/M//s is about 0.73 for as-sputtered samples. Both H//c and M//r/M//s increase with increasing annealing temperatures, especially when annealing temperatures are higher than 400 degree C. These experimental results can be interpreted by using the ferromagnetic exchange coupling and the pinning theory of the coercivity. (Edited author abstract) 13 Refs.

关键词： Cobalt alloys

PREPARATION OF PEROVISKITE-TYPE La_(1-x)Sr_xMnO_3 AT LOW TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 153-156页

作者： Z.B. Shao, L.J. Zhang, Y. Wang and Y. T. Gu (Department of chem.stry, Northeastern university, Shenyang 110004, China) (Shenyang College of Education, Shenyang 110015, China) dept. of chem. Northeastern Univ. Shenyang 110004 China

Peroviskite-type Lal-xSrxMnO3 (0≤x≤0.3) was prepared through the solgel process at low temperature (1100℃). The ethylene glycol and citric acid were used to make a sol-gel from an aqueous solution of lanthanum strontium and manganese nitrated. The particle-diameter distribution of powders is from 10 to 50urn, the mean particle size is about 35urn and the specific surface area is about 92.5 to 98.5m2g-1 .Peroviskite type ***3 was synthesized at 1100℃, and the electronic conductivity of La1-xSrxMnO3 is 104-105S.m-1 from room temperature to 1000℃.

关键词： sol-gel nanometer size peroviskite-type conductivity

Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO_2 Films Deposited by APCVD

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Journal of Materials Science & Technology 1997年第1期13卷 50-56页

作者： Deheng ZHANG(dept. of Physics, shandong university, Jinan 250100, China)Honglei MA(Institute of Optoelectronic Materials and Devices, shandong university, Jinan 250100, China) dept. of Physics Shandong University Jinan 250100 China Institute of Optoelectronic Materials and Devices Shandong University Jinan 250100 China

Transparent conducting F-doped texture SnO2 films with resistivity as low as 5× 10-4 Ω ·cm,with carrier concentrations between 3.5 × 1020 and 7× 1020 cm-3 and Hall mobilities from 15.7 to 20.1 cm2/(V/s) have been prepared by atmosphere pressure chem.cal vapour deposition (APCVD). These polycrystalline films possess a variable preferred orientation, the polycrystallite sizes and orientations vary with substrate temperature. The substrate temperature and fluorine flow rate dependence of conductivity, Hall mobility and carrier conentration fOr the resultingfilms have been obtained. The temperature dependence of the mobiity and carrier concentrationhave been measured over a temperature range 16～400 K. A systematically theoretical analysis on scattering mechanisms for the highly conductive SnO2 films has been given. Both theoretical analysis and experimental results indicate that for these degenerate, polycrystalline SnO2 ：F films in the low temperature range (below 100 K), ionized impurity scattering is main scattering mechanism. However, when the temperature is higher than 100 K, the lattice vibration scattering becomes dominant. The grain boundary scattering makes a small contribution to limit the mobility of the films.

关键词： SnO cm Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO2 Films Deposited by APCVD