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Four-way radial waveguide power divider with high power-handling capacity

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 124-128页

作者： ZHANG Jian-qiong liu qing-xiang LI xiang-qiang ZHAO liu School of Physical Science and Technology Southwest Jiaotong University Chengdu 610031 China

In this paper, a novel four-way radial waveguide power divider with low insertion loss and high power-handling capacity is proposed. This power divider consists of an input coaxial waveguide, a eentral probe, a radial waveguide, four equispaced identical coupling probes, four equispaced identical adjusting posts and four output coaxial waveguides. The novel coupling probes and the adjusting posts are used to realize favorable uniform power division. A power divider with the center frequency of 4.1 GHz is designed, fabricated and measured. Good agreement between simulation and experiment is noted. The measured 15 dB return-loss bandwidth of the power divider is about 600 MHz. The measured 0.5 dB insertion loss bandwidth is wider than 700 MHz. The differences and isolations between the output ports are also discussed. The power-handling capacity of the power divider is analyzed through simulation, and the result proves its usability in high power applications.

关键词： power divider high power low loss multiport radial waveguide

Synthesis of α-Arylated Esters from Aryl Halides

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Chinese Chemical Letters 2006年第5期17卷 595-598页

作者： Wei DENG Ye Feng WANG Lei liu qing xiang GUO Department of Chemistry University of Science and Technology of China Hefei 230026

An operationally simple and inexpensive catalyst system was developed for the cross coupling of aryl iodides and bromides with ethyl acetoacetate by using CuI as catalyst and Nmethyl glycine as ligand. The reaction represents a novel Cu-catalyzed C-C cross coupling reaction. This procedure is applicable to the preparation of pharmaceutically important α- arylalkanoic acids.

关键词： Cross coupling reaction CuI ethyl acetoacetate aryl halide α-arylalkanoic acids.

CuI/Proline-catalyzed N-Arylation of Nitrogen Heterocycles

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Chinese Chemical Letters 2006年第3期17卷 313-316页

作者： Wei DENG Ye Feng WANG Chen ZHANG Lei liu qing xiang GUO Department of Chemistry University of Science and Technology of China Hefei 230026

Ma＇s CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1,4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma＇s original methods.

关键词： Cross coupling reaction CuI N-arylation nitrogen heterocycle proline.

CuI-catalyzed Synthesis of Aryl Thiocyanates from Aryl Iodides

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Chinese Chemical Letters 2006年第10期17卷 1283-1286页

作者： Ye Feng WANG Yuan ZHOU Jia Rui WANG Lei liu qing xiang GUO Department of Chemistry University of Science and Technology of China Hefei 230026

An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium iodide as activator. The procedure is applicable for the synthesis of diverse aryl thiocyanates without any exotic, poisonous reagents.

关键词： Cross coupling reaction CuI aryl thiocyanate,Aryl Iodide 1 10-phenanthroline.

Copper-mediated synthesis of N,N'-diarylhydrazines from boronic acids

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Chinese Chemical Letters 2007年第5期18卷 499-501页

作者： Ye Feng Wang Yuan Zhou Jia Rui Wang Lei liu qing xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

N,N＇-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.

关键词： Cross coupling reaction N,N'-Diarylhydrazines Boronic acids Copper acetate

Blistering and flaking of amorphous alloys bombarded withHe ions

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Nuclear Science and Techniques 2001年第2期12卷 117-125页

作者： HOU Ming-Dong, liu Jie, ZHANG qing-xiang, liu Gang (Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhon 730000 ) Institute of Modern Physics the Chinese Academy of Sciences

The blistering and flaking behavior of many kinds of amorphous alloys under helium ion bombardment at room temperature was investigated. Helium ions with energies of 40keV and 60keV were implanted within the fluence range (1.0～4.0)×1018ions/cm2. The surface topography of samples after irradiation was observed by using a scanning electron microscope. The diameter of blister and the thickness of exfoliated blister lids were measured. The results showed that many kinds of surface topography characteristics appeared for different fluences, energies and amorphous alloys, such as flaking, blistering, exfoliation, blister rupture, secondgeneration blistering and porous structure. The dependdence of surface damage modesand the critical fluence for the onset of blistering and flaking on the sort of materials and ion energy was discussed.

关键词：非晶体合金结泡表面剥落氦离子轰击

A New Cobalt(Ⅱ)Polymer Based on 1-Butylben-zimidazole and Terephthalate Mixed-ligands:Crystal Structure and Weak Interactions

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Chinese Journal of Structural Chemistry 2010年第7期29卷 1033-1038页

作者： WANG Jian-Hua ZHENG Zhan-Ying WU Xiu-Mei WANG Xiu-Guang GUO Jian-Hua liu qing-xiang Tianjin Key Laboratory of Structure and Performance for Functional Molecule College of Chemistry and Life Science Tianjin Normal University Tianjin 300387 China State Key Laboratory of Element-organic Chemistry Nankai University Tianjin 300071 China

A new cobalt（Ⅱ） polymer with quasi-rectangular cavities, [Co（L）2（TP）·H2O]n 1 （L=1-butylbenzimidazole, TP = terephthalate ion） has been prepared by means of self-assembly of 1-butylbenzimidazole, terephthalic acid and Co（NO3）2·6H2O. The structure of 1 was characterized by X-ray diffraction analysis. In the crystal packing, 2-D supramolecular layers are formed via π-π stacking interactions. The fluorescence emission spectra of L and 1 are described.

关键词： benzimidazole terephthalic acid cobalt,π-π interactions

Laboratory study of property-modified prebaked carbon anode and application in large aluminum electrolysis cells

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Journal of Central South University of Technology 2005年第z1期12卷 68-71页

作者： XIAO Jin LI Jie YE Shao-long LAI Yan-qing liu Ye-xiang School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China

A kind of complex additive mainly containing Al, Mg, F, and O was prepared. The synthetical performances of the property-modified prebaked anodes containing additives were tested in laboratory. On the basis of ideal testing results obtained, a large number of industrial prebaked property-modified anodes are prepared in a large-scale aluminum company. Further more, they are all used in 160 kA prebaked anode aluminum electrolysis cells. The statistic result show that, compared with common anodes, the property-modified ones enhance current by 11.6 kg per ton aluminum averagely.

关键词： aluminum electrolysis property-modified anodes laboratory study industrial application

Effects of Bases on the Stabilities of Nucleoside C4'Radicals

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Chinese Chemical Letters 2003年第10期14卷 1073-1076页

作者： Bo Lin LIN, Yao FU, Lei liu, qing xiang GUO Department of Chemistry, University of Science and Technology of China, Hefei 230026 Department of Chemistry University of Science and Technology of China

C4'-H bond dissociation enthalpies of nucleosides were predicted using theoretical methods to a precision of 1-2 Kcal/mol. It was found that the stability of the C4' nucleoside radical is slightly dependent on the bas... 详细信息

关键词： Nucleoside homolysis bond energy DNA lesion substituent effect.