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Synthesis,Crystal Structure and Fluorescent and Thermal Stability Properties of the Zinc(Ⅱ) Complex [Zn(C_(15)H_(11)O_3)_2(C_(12)H_8N_2)_2]·5H_2O 被引量:3
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作者 李昶红 李薇 +1 位作者 胡汉祥 蒋美丽 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第6期947-951,共5页
A new complex has been synthesized with o-methylbenzoyl-benzoic acid(HL) and 1,10-phenanthroline(phen) in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328(18), b... A new complex has been synthesized with o-methylbenzoyl-benzoic acid(HL) and 1,10-phenanthroline(phen) in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328(18), b = 17.7876(18), c = 19.998(2), β = 104.720(4)o, C54H48N4O11Zn, Mr = 994.33, V = 4690.2(9)3, Dc = 1.408 g/cm3, Z = 4, F(000) = 2072, μ(MoKα) = 0.59 mm-1, R = 0.0736 and wR = 0.2029. The crystal structure shows that the zinc ions are coordinated with two oxygen atoms from two HL molecules and four nitrogen atoms from two phen molecules, forming distorted octahedral coordination geometry. The fluorescent and thermal stability properties of the complex are studied. The result shows that it has one fluorescent emission band at around 412 nm. In addition, the complex is stable under 210 ℃. 展开更多
关键词 zinc(Ⅱ) complex SYNTHESIS fluorescent and thermal stability properties
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Crystal Structure,Fluorescence and Thermal Stability Properties of a Dinuclear Copper(Ⅱ) Complex[Cu_2(L)_2(phen)_2]-5H_2O(H_2L = Bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid) 被引量:2
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作者 李昶红 李薇 +1 位作者 李衡峰 谭雄文 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第12期1922-1926,共5页
A new dinuclear copper(II) complex [Cu2(L)2(phen)2]·5H2O (1) with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid (H2L) and 1,10-phenanthroline (phen) as ligands has been synthesized in the mixed sol... A new dinuclear copper(II) complex [Cu2(L)2(phen)2]·5H2O (1) with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid (H2L) and 1,10-phenanthroline (phen) as ligands has been synthesized in the mixed solvents of ethanol and water. It crystallizes in the monoclinic space group P21/c, with a = 17.925(4), b = 19.908(4), c = 11.235(2) A, β = 97.65(3)°, V= 3973.4(14) A3, Dc = 1.552 g/cm^3, Z = 8, F(000) = 1910, the final GOOF = 1.056, R= 0.0519 and wR= 0.1293. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two copper ions are bridged by twoμ2-η1 :η0-3-carboxylate groups of L^2- anions. The fluorescence and thermal stability properties of 1 were studied. The results show that 1 has an intense fluorescent emission at around 381 rim. The TG analysis shows that I is stable below 143 ℃. 展开更多
关键词 dinuclear copper(Ⅱ) complex FLUORESCENCE thermal stability properties
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Crystal Structure and Thermal Stability Properties of a New 1D Chain Cu(Ⅱ)Coordination Polymer with2,3-Pyridinedicarboxylic Acid as the Ligand 被引量:1
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作者 李薇 李昶红 +2 位作者 李衡锋 许金生 李励 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第10期1567-1571,共5页
A new 1D chain copper coordination polymer [CuE(H2L)2(C10HsN2)(HEO)2]n'3n(H20) with 2,3-pyridinedi carboxylic acid (H2L) and 2,2'-bipyridine (2,2'-bipy) as ligands has been synthesized in the mixed etha... A new 1D chain copper coordination polymer [CuE(H2L)2(C10HsN2)(HEO)2]n'3n(H20) with 2,3-pyridinedi carboxylic acid (H2L) and 2,2'-bipyridine (2,2'-bipy) as ligands has been synthesized in the mixed ethanol and water solvents. Crystal data for this complex are as follows: monoclinic, space group P2Jc, a = 7.7713(7), b = 27.478(3), c = 13.2621(13)/1,, fl = 100.6940(10), V= 2782.8(5) A3, Dc = 1.722 g/cm3, Z = 4, p = 1.61 mm-1, F(000) = 1472, the final R = 0.0363 and wR = 0.0933. In the crystal structure, the whole molecule consists of two cooper ions, two H2L, one 2,2"-bipy molecule and six water molecules. Each central copper ion is coordinated with three oxygen atoms from two H2L and one water molecule, two nitrogen atoms from one 2,2'-bipy molecule and two H2L, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated. 展开更多
关键词 copper(II) coordination polymer crystal structure thermal stability properties
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Crystal Structure, Spectroscopic Characterization, and Electrochemical and Thermal Stability Properties of a Dinuclear Nickel(Ⅱ) Complex 被引量:1
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作者 李昶红 陈志辉 +1 位作者 李衡峰 李薇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第7期1093-1098,共6页
A new nickel(Ⅱ) complex Ni2(L)2(2,2'-bipy)2·5.5H2O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2'-bipy) as ligands has been synthesized in the mixed solvent ... A new nickel(Ⅱ) complex Ni2(L)2(2,2'-bipy)2·5.5H2O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2'-bipy) as ligands has been synthesized in the mixed solvent DMF and water(v:v = 5:2). It crystallizes in the triclinic space group P1 with a = 10.414(2), b = 12.884(3), c = 16.176(4) A, α = 70.715(5), β = 80.599(5), γ = 77.383(6)°, V = 1989.4(8) A^3, Dc = 1.531 g/cm^3, Z = 2, F(000) = 958, GOOF = 1.028, the final R = 0.0808 and w R = 0.2036. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two nickel ions are bridged by two μ2-η1:η0 3-carboxylate groups of L2- anions. The coordination environment of Ni(Ⅱ) ion is Ni N2O3, giving a distorted square pyramidal geometry. The thermal stability and electrochemical properties of the complex were investigated. 展开更多
关键词 nickel(Ⅱ) complex electrochemical and thermal stability properties
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Synthesis, Crystal Structure and Thermal Stability Properties of the Supramolecular Complex [Co(phen)_3][(C_6H_5)_2C(OH)COO]_2·7H_2O
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作者 许金生 袁亚莉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第10期1325-1328,共4页
One new cobalt complex [Co(phen)3][(C6Hs)2C(OH)COO]2·7H2O with benzeneacetic acid (BAA), 1,10-phenanthroline and cobaltous perchlorate has been synthesized by means of solvent method. It crystallizes in t... One new cobalt complex [Co(phen)3][(C6Hs)2C(OH)COO]2·7H2O with benzeneacetic acid (BAA), 1,10-phenanthroline and cobaltous perchlorate has been synthesized by means of solvent method. It crystallizes in the triclinic system, space group P^-1, with a = 1.14181(13), b = 1.64417(18), c = 1.65342(18) nm, α = 74.2830(10), β= 84.4490(10), γ = 74.9430(10)°, V = 2.8842(6) nm^3, Dc = 1.359 g/cm^3, Z = 2, F(000) = 1234, R = 0.0621 and wR = 0.1673. The crystal structure shows that the cobalt ion is coordinated with six nitrogen atoms from three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. There are a lot of hydrogen bonds in the complex, from which a two-dimensional network is constructed. The result of TG analysis shows that the title complex is stable below 130.0 ℃. 展开更多
关键词 cobalt(Ⅱ) complex crystal structure thermal stability properties
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Synthesis,Structure,Luminescence and Thermal Stability Properties of a New(3,4)-Connected 2D Zn Coordination Polymer 被引量:2
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作者 WANG Hai-Peng WANG Hong-Liang LI Bao-Long 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2020年第10期1835-1840,1743,共7页
A new zinc coordination polymer{[Zn2(ttmb)2(dca)4(H2O)].H2O}n(1.H2O)was synthesized by the reaction of 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene(ttmb),Zn(Ⅱ)salt and sodium dicyanamide(Na(dca)).The structure of the ... A new zinc coordination polymer{[Zn2(ttmb)2(dca)4(H2O)].H2O}n(1.H2O)was synthesized by the reaction of 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene(ttmb),Zn(Ⅱ)salt and sodium dicyanamide(Na(dca)).The structure of the title compound was determined by single-crystal X-ray diffraction,elemental analyses and IR spectra.1 exhibits a(3,4)-connected 2D double-layer network with the point symbol of{63}{(66}.The solid-state luminescence shows a strong emission band at 485 nm upon excitation at 384 nm.The thermal stability properties were also studied. 展开更多
关键词 coordination polymer STRUCTURE (3 4)-connected LUMINESCENCE thermal stability properties
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Synthesis, Crystal Structure, Fluorescence, Thermal Stability and Magnetic Properties of the Dinuclear Manganese(Ⅱ) Complex [Mn_2(L)_2(2,2'-bipy)_2(H_2O)_5]_2·3H_2O 被引量:2
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作者 LI Wei LI Chang-Hong +1 位作者 LI Yu-Lin LI Heng-Feng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第6期973-978,共6页
A new dinuclear manganese complex [Mn2(L)2(2,2'-bipy)2(H2O)512·3H2O has been synthesized with MnSO4·H2O, 2,2'-bibenzoic acid (H2L) and 2,2'-bipyridine(2,2'-bipy) in the mixed solvent ethanol an... A new dinuclear manganese complex [Mn2(L)2(2,2'-bipy)2(H2O)512·3H2O has been synthesized with MnSO4·H2O, 2,2'-bibenzoic acid (H2L) and 2,2'-bipyridine(2,2'-bipy) in the mixed solvent ethanol and water. It crystallizes in monoclinic, space group Pi with a = 9.9944(10), b = 21.939(2), c = 25.628(3) A, a = 108.429(3), β = 100.613(4), 7 = 102.821(3)°, V = 4997.9(9) A3, Dc= 1.355 g/cm^3, Z = 2, F(000) = 2108, GOOF = 1.074, the R= 0.0626 and wR= 0.1531. The structure of the complex contains two [Mn2(L)2(2,2'-bipy)2] units, ten coordinated H2O molecules and three uncoordinated H2O molecules. The fluorescence, thermal stability and magnetic properties of the complex were investigated. 展开更多
关键词 dinuclear manganese complex FLUORESCENCE thermal stability and magnetic properties
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Hydrothermal Synthesis, Crystal Structure, Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex 被引量:2
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作者 李昶红 李薇 +1 位作者 胡汉祥 胡波年 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第10期1553-1557,共5页
A new dinuclear copper(Ⅱ) complex [Cu(CH3COO)(C7H5N4)(H2O)]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallize... A new dinuclear copper(Ⅱ) complex [Cu(CH3COO)(C7H5N4)(H2O)]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallizes in the monoclinic space group P21/c, with a = 12.0188(7), b = 13.7993(8), c = 8.7488(5) A, β = 101.7350(10)o, V = 1420.67(14) A3, D3 c = 1.568 g/cm, Z = 1, F(000) = 690, the final GOOF = 1.145, R = 0.0437, and w R = 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ2-η1:η0 3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Cu(Ⅱ) ion is Cu O2N3, giving a distorted square pyramidal geometry. The thermal stability and magnetic properties of the complex were investigated. 展开更多
关键词 copper(Ⅱ) complex thermal stability and magnetic properties
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Effects of terbium sulfide addition on magnetic properties,microstructure and thermal stability of sintered Nd-Fe--B magnets 被引量:1
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作者 李向斌 刘硕 +4 位作者 曹学静 周贝贝 陈岭 闫阿儒 严高林 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期423-426,共4页
To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into(Pr(0.25)Nd(0.75))(30.6)Cu(0.15)Fe(bal)B1(wt.%) b... To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into(Pr(0.25)Nd(0.75))(30.6)Cu(0.15)Fe(bal)B1(wt.%) basic magnets. The effects of the addition of terbium sulfide on magnetic properties, microstructure, and thermal stability of sintered Nd–Fe–B magnets are investigated.The experimental results show that by adding 3 wt.% Tb2S3, the coercivity of the magnet is remarkably increased by about 54% without a considerable reduction in remanence and maximum energy product. By means of the electron probe microanalyzer(EPMA) technology, it is observed that Tb is mainly present in the outer region of 2:14:1 matrix grains and forms a well-developed Tb-shell phase, resulting in enhancement of HA, which accounts for the coercivity enhancement.Moreover, compared with Tb2S3-free magnets, the reversible temperature coefficients of remanence(α) and coercivity(β) and the irreversible flux loss of magnetic flow(hirr) values of Tb2S3-added magnets are improved, indicating that the thermal stability of the magnets is also effectively improved. 展开更多
关键词 terbium sulfide magnetic property microstructure thermal stability
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Magnetic Properties and Thermal Stability of Pr_(1-x)La_xCo_(5-y)Alloys
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作者 Fazeng LIAN (Dept. of Materials Science and Engineering, Northeastern University, Shenyang, 110006, China)Meiqing HUANG, S.Simizu and W.E.Wallace (Carnegie Mellon Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第6期463-465,共3页
Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic pr... Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic properties for the Pr0.85La0.15Co4.3 and Pr0.75La0.25Co4.1 magnets are iHc=368 kA/m, Br=0.91 T, (BH)max=145.6 kJ/m3, αBr=-0.03%/℃ and iHc=568 kA/m,Br=0.8 T, (BH)max=127.2 kJ/m3,αBr,=-0.06%/℃, respectively The phase structures of as-cast alloys and magnets were investigated 展开更多
关键词 LA x)La_xCo Magnetic properties and thermal stability of Pr y)Alloys
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Synthesis, Crystal Structure and Thermal Stability of a New Binuclear Cu(Ⅱ) Complex with 2-Benzoylbenzoic Acid as the Ligand 被引量:2
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作者 李昶红 李薇 +2 位作者 胡波年 胡汉祥 彭爱成 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第8期1264-1268,共5页
A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic... A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated. 展开更多
关键词 copper(II) complex 2-benzoyibenzoic acid crystal structure thermal stability properties
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Hydrothermal Synthesis,Crystal Structure and Thermal Stability of [Ni(phen)_3]·(C_8H_(12)O_4)·(H_2O)_(14)
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作者 张少华 李昶红 +2 位作者 杨颖群 李薇 李玉林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第12期1427-1430,共4页
One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = ... One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = 2.3475(5), b = 1.2208(2), c = 1.9499(4) nm, β= 114.682(3)°, V = 5.0778(16) nm^3, Dc = 1.339 g/cm^3, Z = 4,μ(MoKa) = 0.458 mm^-1, F(000) = 2168, GOOF = 1.014, R = 0.0401 and wR = 0.0961. The nickel(H) center in the title complex is coordinated with six nitrogen atoms of three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. However, the nickel(Ⅱ) ion does not coordinate to the hexane dicarboxylic acid. The complex molecules form a 3D structure through hydrogen bonds. TG analysis shows that the title complex is stable below 240.0 ℃. 展开更多
关键词 nickel(Ⅱ) complex hydrothermal synthesis thermal stability property
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Effect of Ga_2O_3 on Structure and Properties of Calcium Aluminate Glasses 被引量:1
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作者 王衍行 ZU Chengkui +2 位作者 HE Kun ZHAO Huifeng LIU Yonghua 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第5期961-964,共4页
The effect of Ga_2O_3 on the structure and properties of calcium aluminate glasses fabricated by vacuum melting process was investigated by Raman spectrum, differential scanning calorimeter(DSC), and infrared spectr... The effect of Ga_2O_3 on the structure and properties of calcium aluminate glasses fabricated by vacuum melting process was investigated by Raman spectrum, differential scanning calorimeter(DSC), and infrared spectrum methods. The results show that calcium aluminate glass network only consists of [AlO_4] tetrahedral units. With the gradual addition of Ga_2O_3, the quantity of [GaO_4] tetrahedral units increases. Substitution of Ga_2O_3 for Al_2O_3 results in a decrease in Tg, Tx, and Tp, and an increase in the thermal stable index ΔT. Similarly, the absorption band around 3.0 μm obviously reduces and the transparency in 4.0-6.0 μm rapidly increases with increasing Ga_2O_3 content. However, the chemical stability of calcium aluminate glasses decreases if Ga_2O_3 is introduced due to the increasing of [GaO_4] units in the glass network. 展开更多
关键词 calcium aluminate glass structure thermal property infrared property chemical stability
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Syntheses, Structure and Properties of a Strontium(Ⅱ) Complex with 5-Sulfoisophthalic Acid Monosodium 被引量:1
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作者 冯建华 王小锋 +1 位作者 张志强 吴刚 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第3期428-434,共7页
A new Sr(Ⅱ) complex, [Sr(Hsip)(H2O)] (1, NaH2sip = 5-sulfoisophthalic acid monosodium), has been synthesized by solvothermal reaction of SrCO3 and NaH2sip at 120 ℃, and characterized by single-crystal X-ray ... A new Sr(Ⅱ) complex, [Sr(Hsip)(H2O)] (1, NaH2sip = 5-sulfoisophthalic acid monosodium), has been synthesized by solvothermal reaction of SrCO3 and NaH2sip at 120 ℃, and characterized by single-crystal X-ray diffraction studies, elemental analysis and FT-IR. Single- crystal X-ray diffraction reveals that compound 1 has a 3D architecture, and there is only one crystallographically independent Sr(Ⅱ) ion in 1. The coordination geometry of Sr(Ⅱ) is a distorted tetragonai anti-prism. The whole Hsip2- ligand performs aμ6-coordination model. In the solid state, complex 1 shows luminescence with the maximum emission intensity at 417 nm upon excitation at 320 nm. Thermal stability of complex 1 was also investigated. 展开更多
关键词 Sr(Ⅱ) complex sulfonate group luminescence property thermal stability
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Analysis on the Characteristic Properties of PEDOT Nano-particle Based on Reversed Micelle Method
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作者 郑华靖 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第3期422-428,共7页
Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,w... Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT. 展开更多
关键词 poly (3 4-ethylenedioxythiophene) conducting polymer reversed micelle nano-particle photoelectric properties thermal stability
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Structure, magnetic properties, and thermal stability of Sm(1-x)Tm_xCo_5compounds
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作者 Jian-Hua Zuo Ming Yue +5 位作者 Qing-Mei Lu Dong-Tao Zhang Xue-Xu Gao Jiu-Xing Zhang Zhao-Hui Guo Wei Li 《Rare Metals》 SCIE EI CAS CSCD 2014年第2期176-179,共4页
Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction(XRD), thermal magnetic analysis(TMA), and magnetic measurements. XRD results show that all ... Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction(XRD), thermal magnetic analysis(TMA), and magnetic measurements. XRD results show that all the compounds have a main phase of hexagonal CaCu5-type crystal structure with small amount of impurity phases; increasing Tm content is associated with contraction of the hexagonal unit cell in the direction of the c axis and expansion of the a and b parameters. TMA results indicate that the Curie temperature(TC) of Sm1-xTmxCo5 compounds gets higher with the increase in Tm content.Magnetic measurements show that both the magnetic anisotropy field(HA) and the magnetization at an applied field of 7 T(M7 T) decrease with the increase of Tm content. However, the thermal stability of both the HAand M7 Tof all the Tm doped compounds is remarkably improved compared with that of the pure SmCo5 compound, leading to the result that both the M7 Tand HAof Sm0.8Tm0.2Co5 .2are higher than those of SmCo5 compound at 473 K, which indicates the good potential of Tm doped compound in the practical applications at elevated temperature. 展开更多
关键词 Sm1-xTmxCo5 compounds Crystal structure Intrinsic magnetic property thermal stability
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Mechanical and thermal properties of mesogen-jacketed liquid crystalline polymer/epoxy resin composites 被引量:4
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作者 Chunpeng Chai Fangfang Yin +1 位作者 Guoping Li Yunjun Luo 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第6期1021-1026,共6页
The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by i... The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis(TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction(WAXD) and scanning electron microscope(SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin. 展开更多
关键词 mesogen-jacketed liquid crystalline polymer epoxy resin mechanical properties thermal stability properties
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Synthesis and Characterization of Fluorinated Polyurethane Containing Carborane in the Main Chain: Thermal, Mechanical and Chemical Resistance Properties 被引量:5
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作者 Ning Li Fang-Lei Zeng +5 位作者 Yu Wang De-Zhi Qu Chun Zhang Juan Li Jin-Zhao Huo Yong-Ping Bai 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2018年第1期85-97,共13页
In this study, two fluorinated polyurethanes(FPU) containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer(HDI trimer) with fluorin... In this study, two fluorinated polyurethanes(FPU) containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer(HDI trimer) with fluorinated polyesters(CFPETs) having hydroxyl-terminated carborane groups at room temperature. The structures of carborane fluorinated polyesters(CFPETs) and polyurethanes(CFPUs) were characterized by gel permeation chromatography(GPC), Fourier transform infrared(FTIR) spectroscopy and nuclear magnetic resonance(NMR) measurements. The thermal stability, mechanical properties, Shore A hardness, solvent resistance and acid-alkali resistance of the carborane fluorinated polyurethane films were also studied. Thermogravimetric analysis(TGA) tests manifested that the introduction of carborane groups into the main chain of fluorinated polyurethane endowed the obtained fluorinated polyurethane with excellent thermal stability. The thermal decomposition temperature of carborane fluorinated polyurethane(CFPU) increased by 190 °C compared with that of the carborane-free fluorinated polyurethane(FPU). Even at 800 °C, CFPU showed the char yield of 66.5%, which was higher than that of FPU(34.3%). The carborane-containing fluorinated polyurethanes also showed excellent chemical resistance and prominent mechanical property even after the cured films being immersed into Jet aircraft oil or 37% HCl for 168 h or at high temperature(700 °C). It is found that the structural characteristics of carborane group and the compacted structure of CFPU effectively improve the thermal stability, mechanical property, solvent resistance and acid-alkali resistance of the carborane-free fluorinated polyurethane. These excellent properties make CFPU as the useful raw materials to prepare the high temperature resistant coatings or adhesives for automotive engines, engine or fuel tank of aircraft and other equipment working in high-temperature or high concentrations of acid-alkali environments. 展开更多
关键词 Fluorinated polyurethane Carborane thermal stability Mechanical property Chemical resistance
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Effect of niobium substitution on microstructures and thermal stability of TbCu7-type Sm-Fe-N magnets 被引量:5
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作者 Guiyong Wu Hongwei Li +6 位作者 Dunbo Yu Kuoshe Li Wenlong Yan Chao Yuan Liang Sun Yang Luo Kun Zhang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2018年第3期281-286,共6页
This paper reports crystal structures, magnetic properties and thermal stability of TbCu7-type Sm(8.5)Fe((85.8-x)Co(4.5)Zr(1.2)Nbx(x = 0-1.8) melt-spun compounds and their nitrides, investigated by means of... This paper reports crystal structures, magnetic properties and thermal stability of TbCu7-type Sm(8.5)Fe((85.8-x)Co(4.5)Zr(1.2)Nbx(x = 0-1.8) melt-spun compounds and their nitrides, investigated by means of X-ray diffraction, vibrating sample magnetometer, flux meter and transmission electron microscope. It is found that the lattice parameter ratio c/a of TbCu7-type crystal structure increases with Nb substitution, which indicates that the Nb can increase the stability of the metastable phase in the Sm-Fe ribbons. Nb substitution impedes the formation of magnetic soft phase a-Fe in which reversed domains initially form during the magnetization reversal process. Meanwhile, Nb substitution refines grains and leads to homogeneous micro structure with augmented grain boundaries. Thus the exchange coupling pining field is enhanced and irreversible domain wall propagation gets suppressed. As a result, the magnetic properties are improved and the irreversible flux loss of magnets is notably decreased. A maximum value 771.7 kA/m of the intrinsic coercivity H(cj) is achieved in the 1.2 at% substituted samples.The irreversible flux loss for 2 h exposure at 120 ℃ declines from 8.26% for Nb-free magnets to 6.32% for magnets with 1.2 at% Nb substitution. 展开更多
关键词 Magnetic properties thermal stability Grain size Pinning field Irreversible flux loss Rare earths
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Modification of Liquid Silicone Rubber by Octavinyl-polyhedral Oligosilsesquioxanes and Silicon Sol 被引量:1
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作者 白洪强 yi shengping +2 位作者 huang chi 黎厚斌 廖俊 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第2期229-236,共8页
To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber(LSR), a series of modified LSR samples were prepared by introducing octavinyl-p... To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber(LSR), a series of modified LSR samples were prepared by introducing octavinyl-polyhedral oligosilsesquioxanes(VPOSS) and high purity silicon sol singly or in combination before vulcanization. Significant correlation was found between the loading rate of VPOSS and thermal properties. However, mechanical properties were negatively correlated with VPOSS content within the range experimented, which may be ascribed to material defect caused by uneven distribution and aggregation. Furthermore, test results approved that the introducing of silicon sol indeed affected the stabilities of the polymer by restraining the material defect caused by the aggregation of POSS molecules and improving cross link density. For example, adding 10%-20% of silicon sol into VPOSS(1.0%) modified LSR will increase tear resistance by 43.9%-85.7%, elongation at break by 31.7%-57.3%, residue at 800 ℃ in N2 atmosphere by 32.0%-37.9%, residue at 650 ℃ in air atmosphere by 70.9%-91.6%, respectively. This work proves that, to incorporate VPOSS into LSR by hydrosilylation, and to use silicon sol as dispersant and reinforce filler can become an efficient way to improve the mechanical property, thermal stability and bio-compatibility of LSR in the future. 展开更多
关键词 POSS LSR silicon sol thermal stabilities mechanical properties
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