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An atomistic simulation of site preference and vibrational properties of UMxAl12-x (M = Fe, Co, Ni, Cr and Mn) and UMxAl12-xHx

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Progress in Natural Science:Materials International 2009年第8期19卷 983-989页

作者： Huijun Tian a,b, Ping Qian a, Jiang Shen a, Nanxian Chen a,c a Institute of Applied Physics, Beijing university of Science and technology, Beijing 100083, china b School of Physics, Beijing university of chemical technology, Beijing 100029, china c Department of Physics, Tsinghua university, Beijing 100084, china [a]Institute of Applied Physics Beijing University of Science and Technology Beijing 100083 China [b]School of Physics Beijing University of Chemical Technology Beijing 100029 China [c]Department of Physics Tsinghua University Beijing 100084 China

A series of lattice inversion pair potentials are used to evaluate the phase stability and site preference for uranium intermetallics UMxAl12 x (M = Fe, Co, Ni, Cr and Mn) and their related hydrides. Calculated results show that Fe, Co, Ni, Cr or Mn atoms preferentially substitute Al at the 8f site. Interstitial H atoms only occupy 2b interstitial sites in UMxAl12 x. Calculated lattice constants are found to agree with a report in the literature. Elastic constants and bulk modulus of UMxAl12 x and UMxAl12 xH were also investigated. In particular, the phonon densities of states (DOS) of these actinide compounds were evaluated for the first time.

关键词： Interatomic potentials Site preference Lattice vibration

Hydroisomerization of n-heptane over bimetal-bearing H_3PW_(12)O_(40) catalysts supported on dealuminated USY zeolite

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Science china Chemistry 2008年第2期51卷 120-127页

作者： WEI RuiPing1,2, GU YanBo1 & WANG Jun1 1 State Key Laboratory of Materials-Oriented chemical Engineering, College of Chemistry and chemical Engineering, Nanjing Uni- versity of technology, Nanjing 210009, china 2 College of Chemistry and chemical Engineering, Southeast university, Nanjing 211189, china State Key Laboratory of Materials-Oriented chemical Engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjing 210009China College of Chemistry and chemical Engineering Southeast UniversityNanjing 211189China

The bimetal-bearing (CePt or LaPt) 12-tungstophosphoric acid (H3PW12O40 (PW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XRD, BET, IR, and H2-chemisorption. Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor. After the steam treatment combined with the acid leaching, as well as the supporting with PW and the bimetals, the DUSY support retains the Y zeolite porosity and the PW well keeps its Keggin structure in catalysts. The doping of Ce into the catalysts enhances the dispersion of Pt on the catalyst surface. The Pt-bearing PW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered reaction temperatures. At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h1, the catalyst with a Pt loading of 0.4%, PW loading of 10% and a molar ratio of Ce to Pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

关键词： hydroisomerization of n-heptane bimetal catalyst heteropoly acid USY platinum

Catalytic performance of Fe_3O_4-CoO/Al_2O_3 catalyst in ozonation of 2-(2,4-dichlorophenoxy) propionic acid,nitrobenzene and oxalic acid in water

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Journal of Environmental Sciences 2010年第10期22卷 1623-1628页

作者： Shaoping Tong,Rui Shi,Hua Zhang,Chunan Ma College of chemical Engineering and Materials Science,State Key Laboratory Breeding Base of Green Chemistry-Synthesis technology,Zhejiang university of technology,Hangzhou 310032,china [a] College of chemical Engineering Materials Science State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology Zhejiang University of Technology Hangzhou 310032 China

Fe3O4-CoO/Al2O3 catalyst was prepared by incipient wetness impregnation using Fe（NO3）3.9H2O and Co（NO3）2.6H2O as the precursors, and its catalytic performance was investigated in ozonation of 2-（2,4-dichlorophenoxy）propionic acid （2,4-DP）, nitrobenzene and oxalic acid. The experimental results indicated that Fe3O4-CoO/Al2O3 catalyst enabled an interesting improvement of ozonation efficiency during the degradation of each organic pollutant, and the Fe3O4-CoO/Al2O3 catalytic ozonation system followed a radical-type mechanism. The kinetics of ozonation alone and Fe3O4-CoO/Al2O3 catalytic ozonation of three organic pollutants in aqueous solution were discussed under the mere consideration of direct ozone reaction and OH radical reaction to well investigate its performance. In the catalytic ozonation of 2,4-DP, the apparent reaction rate constants （k） were determined to be 1.456 × 10^-2 min-1 for ozonation alone and 4.740 × 10^-2 min^-1 for O3/Fe3O4-CoO/Al2O3. And O3/Fe3O4-CoO/Al2O3 had a larger Rot （6.614 × 10^-9） calculated by the relative method than O3 did （1.800 x 10-9）, showing O3/Fe3O4-CoO/Al2O3 generated more hydroxyl radical. Similar results were also obtained in the catalytic ozonation of nitrobenzene and oxalic acid. The above results demonstrated that the catalytic performance of Fe3O4-CoO/Al2O3 in ozonation of studied organic substance was universal to a certain degree.

关键词： catalytic ozonation Fe3O4-CoO/Al2O3 2,4-DP nitrobenzene oxalic acid kinetics

Short cycle structures for graphs on surfaces and an open problem of Mohar and Thomassen

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Science china Mathematics 2006年第2期49卷 212-224页

作者： REN Han & DENG Mo Department of Mathematics, east china Normal university, Shanghai 200062, china College of Mathematics & Information Science, Northwest Normal university, Lanzhou 730070, china 1. Department of Mathematics East China Normal University Shanghai 200062 China 2. College of Mathematics & Information Science Northwest Normal University Lanzhou 730070 China

In this paper we investigate cycle base structures of a (weighted) graph and show that much information of short cycles is contained in an MCB (i.e., minimum cycle base). After setting up a Hall type theorem for base-transformation, we give a sufficient and necessary condition for a cycle base to be an MCB. Furthermore, we show that the structure of MCB in a (weighted)graph is unique. The property is also true for those having a longest length (although much work has been down in evaluating MCB, little is known for those having a longest length). We use those methods to find out some unknown properties for short cycles sharing particular properties in (unweighted) graphs. As applications, we determine the structures of short cycles in an embedded graph and show that there exist polynomially bounded algorithms in finding a shortest contractible cycle and a shortest two-sided cycle provided such cycles exist. Those answer an open problem of B. Mohar and C. Thomassen.

关键词： cycle base facial cycle graph embedding.

V_2O_5/C catalyst for liquid phase oxidation of glyoxal to glyoxylic acid

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Science china Chemistry 2009年第7期52卷 1057-1062页

作者： NIU YuLan1,2 & LI RuiFeng1 1 Key Laboratory of Coal Science and technology, Ministry of Education, Institute of Special chemicals, Taiyuan university of technology, Taiyuan 030024, china 2 Department of chemical Engineering, Taiyuan Institute of technology, Taiyuan 030008, china Key Laboratory of Coal Science and technology Ministry of Education Institute of Special Chemicals Taiyuan University of Technology Taiyuan 030024 China Department of chemical Engineering Taiyuan Institute of Technology Taiyuan 030008 China

A study of the catalytic activity of V2O5/C catalyst for the oxygen oxidation of glyoxal has been made, showing that glyoxylic acid can be formed without control of pH value and there is little oxalic acid from the excessive oxidation of glyoxylic acid. The studies of XRD and TEM have shown that V2O5 diffraction peaks gradually strengthen with the increase of the content of V2O5. With the content of 3% V2O5 and the calcination temperature of 573 K, V2O5/C catalyst displayed the best activity and selectivity. The conversion of glyoxal and the selectivity of glyoxylic acid reached 18.76% and 77.70% after 5 h, respectively. Moreover, V2O5/C catalyst showed small deactivation after recycling three times, which indicates that V2O5/C has a higher stability than noble metal catalysts in the reaction medium.

关键词： glyoxal glyoxylic acid V2O5/C catalyst

Aliphatic Phosphenium Canon Featuring A P-S Bond

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Chinese chemical Letters 1999年第3期10卷 205-206页

作者： Tian Bac HUANG Linu Fei LIU Xuang Long XU Wen Fang HUANG Ke WANG (Institute of Pesticides and Pharmaceuticals,east china university of Seience and technology,Institute of Organi Synthesis,Central china Normal university ,Wuhan 430079) E china Univ Sci & Technol Inst Pesticides & Pharmaceut Shanghai 200237 Peoples R China Cent china Normal Univ Inst Organ Synth Wuhan 430079 Peoples R China

The first aliphatic phosphenium cation featuring a P-S bond (dimethylamino)(methylthio)phosphenium cation *** been prepared by treatument of the (dimethylamino)(methylthio) chlorophosphines 2 wih the stoichiometri qua... 详细信息

关键词： Phosphenium cation chlorophosphine ^(31)p nmr spectroseopy

Analysis of variance for testing method of cement in determination of strength

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Progress in Natural Science:Materials International 2011年第4期21卷 341-346页

作者： Hong HUANG,Xiao-dong SHEN State Key Laboratory of Materials-Oriented chemical Engineering,College of Material Science and Engineering, Nanjing university of technology,Nanjing 210009,china State Key Laboratory of Materials-Oriented chemical Engineering College of Material Science and Engineering Nanjing University of Technology Nanjing 210009 China

The statistical tools such as descriptive statistics,full factorial design and analysis of source of variation were used to identify the potential factors that impact the validity of testing method for determining the strength of *** results showed that personal error impacted both accuracy and precision of test *** time associated with temperature fluctuation resulted in strength variation but did not impact the precision of test in all curing *** compactions did not impact the precision of test but resulted in the strength variation on 3 d and 28 d *** methods for the initial moist air curing significantly impacted the precision of testing method and resulted in the strength variation of cement on 1 d.

关键词： testing method of cement analysis of variance strength accuracy precision

MULTI-PEAK MATCH INTENSITY RATIO METHOD OF QUANTI-TATIVE X-RAY DIFFRACTION PHASE ANALYSIS

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Acta Metallurgica Sinica(English Letters) 2003年第6期16卷 489-494页

作者： G. Chu, Y.F. Cong and H.J. YouResearch Center of Analysis and Test, Liaoning university of Petroleum & chemical technology, Fushun 113001, china Res. Ctr. of Analysis and Test Liaoning Univ. of Petrochem. Tehnol. Fushun 113001 China

A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.

关键词： X-ray diffraction multi-peak match intensity ratio quantitative phase analysis

Process optimization of reaction of acid leaching residue of asbestos tailing and sodium hydroxide aqueous solution

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Science china(Technological Sciences) 2009年第1期52卷 204-209页

作者： DU GaoXiang1,3, ZHENG ShuiLin2 & DING Hao1 1 School of Materials Science and technology, china university of Geosciences (Beijing), Beijing, 100083, china 2 School of chemical and Environment Engineering, china university of Mining and technology (Beijing), Beijing 100083, china 3 Hebei Qinghe Refractory Group Co. Ltd., Xingtai 054804, china 1. School of Materials Science and technology China University of Geosciences (Beijing) Beijing 100083 China 3. Hebei Qinghe Refractory Group Co. Ltd. Xingtai 054804 China 2. School of chemical and Environment Engineering China University of Mining and Technology (Beijing) Beijing 100083 China

Silica is the major component of the acid leaching residue of asbestos tailing. The waterglass solution can be prepared by the reaction of the residue with sodium hydroxide aqueous solution. Compared to the high temperature reaction method, this process is environmental friendly and low cost. In this paper, the reaction process of the residue and the sodium hydroxide aqueous solution is optimized. The optimum reaction process parameters are as follows: the usage of sodium hydroxide is 26.4 g/100 g acid leaching residue, the reaction temperature is 90℃, the reaction time is 1 h, and the ratio of the liquid/solid is 2.0. The significance sequence of the process parameters to the alkali leaching reaction effect is the usage of sodium hydroxide > the ratio of the liquid/solid > the reaction time > the reaction temperature. The significance sequence to the leaching ratio of SiO2 is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. The significance sequence to the modulus of the sodium silicate is the ratio of the liquid/solid > the usage of sodium hydroxide > the reaction time > the reaction temperature. Under the optimum conditions, the leaching ratio of the SiO2 is 77.5%, and the modulus of the sodium silicate is 3.15. The XRD analysis result indicates that the major components of the alkali leaching residue are serpentine, talc, quartz and some albite.

关键词： asbestos tailing acid leaching residue sodium hydroxide process optimization