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Tuning of the textural features and acidic properties of sulfated mesoporous lanthana-zirconia solid acid catalysts for alkenylation of diverse aromatics to their corresponding α-arylstyrenes
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作者 赵忠奎 冉金凤 +2 位作者 郭永乐 苗博元 王桂茹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1303-1313,共11页
The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids (SO42?/meso‐La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9O... The textural features and acidic properties of sulfated mesoporous lanthana‐zirconia solid acids (SO42?/meso‐La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso‐La0.1Zr0.9Oδcomposites, such as the molar ratio of the template to La and Zr metal ions (Nt/m), molar ratio of ammonia to La and Zr metal ions (Na/m), hydrothermal temperature (Thydro), and hy‐drothermal time (thydro). The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p‐xylene with phenylacetylene was investi‐gated. Various characterization techniques such as N2 physisorption, X‐ray diffraction, NH3 temper‐ature‐programmed desorption, and thermogravimetric analysis were employed to reveal the rela‐tionship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso‐La0.1Zr0.9Oδcomposite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t‐ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42?/meso‐La0.1Zr0.9Oδcatalyst exhibited much superior catalytic activity and coke‐resistant stabil‐ity. Moreover, the developed SO42?/meso‐La0.1Zr0.9Oδcatalyst demonstrated excellent catalytic per‐formance for alkenylation of diverse aromatics with phenylacetylene to their correspondingα‐arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42?/meso‐La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production ofα‐arylstyrenes through clean and atom efficient solid‐acid‐mediated Friedel‐Crafts alkenylation of diverse aromatics with phenylacetylene. 展开更多
关键词 Mesoporous solid acid ALKENYLATION Clean synthesis Alkenyl aromatics Textural and acidic properties Tuning
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Synthesis of NbFAPO-5 and NbFAPSO-5 Molecular Sieve by Hydrothermal Method and Comparison of Their XRD Patterns and Their Acidic Properties Evaluation by Infrared Spectroscopy
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作者 Mominou Nchare Lei Wang Salomon Anagho 《Open Journal of Inorganic Chemistry》 2016年第3期155-162,共9页
Mesoporous molecular sieves, NbFAPO-5 and NbFAPSO-5 were hydrothermally synthesized with AlPO-5 type structure. Characterization of these molecular sieves was performed by X-ray diffraction to determine their structur... Mesoporous molecular sieves, NbFAPO-5 and NbFAPSO-5 were hydrothermally synthesized with AlPO-5 type structure. Characterization of these molecular sieves was performed by X-ray diffraction to determine their structure, ICP-EAS for their elemental composition and infrared spectrometry to access their acidic properties. X-ray diffraction patterns confirmed well AlPO-5 type structure. ICP-EAS analysis confirmed the incorporation of silicon (12.9%), aluminium (15.4%), phosphorous (21.9%), iron (5.62%) and niobium (0.39%) into AlPO-5 framework. Infrared spectrometry analysis showed that both Bronsted and Lewis sites were found in the synthesized samples. The presence of both Bronsted and Lewis acid site led to bifunctional function of NbFAPO-5 and NbFAPSO-5 molecular sieve in promoting both oxidation and esterification reactions. NbFAPSO-5 Bronsted acidity was higher than that of NbFAPO-5 and for Lewis acidity, NbFAPO-5 was higher than that of NbFAPO-5. 展开更多
关键词 NIOBIUM AlPO-5 Molecular Sieve Hydrothermal Synthesis Acid properties
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Crystal Structure and Magnetic Properties of a Dinuclear Terbium Compound Tb_2(μ_2-anthc)_4(anthc)_2(1,10-phen)_2 被引量:6
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作者 韩长宝 王玉玲 刘庆燕 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第4期705-710,共6页
A dinuclear Tb(Ⅲ) compound, Tb_2(μ_2-anthc)_4(anthc)_2(1,10-phen)_2(1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline), was synthesized under solvothermal condition and structural... A dinuclear Tb(Ⅲ) compound, Tb_2(μ_2-anthc)_4(anthc)_2(1,10-phen)_2(1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline), was synthesized under solvothermal condition and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P1, with a = 12.5061(12), b = 13.3168(10), c = 15.0079(12) ?, α = 110.620(7), β = 102.941(7), γ = 107.036(7)o, V = 2081.8(3) ?~3, Z = 1, C_(114)H_(70)N_4O_(12)Tb_2, M_r = 2005.58, D_c = 1.600 g/cm^3, μ = 1.759 mm^(-1), F(000) = 1008, the final R = 0.0294 and w R = 0.0608 for 8900 observed reflections with I 〉 2s(I). In compound 1, two Tb(Ⅲ) ions are linked by four carboxylate groups of the bridging anthc– ligands to give a dinuclear Tb_2(μ_2-anthc)_4 unit wherein each Tb(III) ion is further capped by a terminal anthc– ligand and a 1,10-phen ligand in a chelating fashion. Detailed direct-current and alternating-current susceptibility measurements showed no slow magnetism relaxation phenomenon was observed for 1. 展开更多
关键词 Tb(Ⅲ) compound 9-anthracenecarboxylic acid magnetic property crystal structure
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Syntheses,Crystal Structures,and Magnetic Properties of Two Manganese(Ⅱ) Coordination Polymers Based on Bifunctional Pyridine-benzene Carboxylic Acids 被引量:3
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作者 黄胜 蒋畅 +1 位作者 姚枫枫 康杰 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第8期1260-1268,共9页
Two manganese(II) coordination polymers, namely, {[Mn(PIP)(BIBP)]·(BIBP)0.5}n(1) and {[Mn(PTA)(BIMBP)(H2O)]·H2O(0.69)}n(2)(H2PIP = 5-(4-pyridyl)-isophthalic acid, H2 PTA =6-(4-pyridyl... Two manganese(II) coordination polymers, namely, {[Mn(PIP)(BIBP)]·(BIBP)0.5}n(1) and {[Mn(PTA)(BIMBP)(H2O)]·H2O(0.69)}n(2)(H2PIP = 5-(4-pyridyl)-isophthalic acid, H2 PTA =6-(4-pyridyl)-terephthalic acid, BIBP = 4,4?-bis(imidazol-1-yl)biphenyl, and BIMBP =4,4?-bis(imidazol-1-ylmethyl)biphenyl), have been synthesized by using the bifunctional pyrinde-benzene carboxylic acids and bis(imidazole) linkers as mixed ligands to react with Mn SO4,and further characterized by elemental analysis, IR, and PXRD. Compound 1 is in the triclicnic system, space group P1 with a = 10.1089(8), b = 13.1927(12), c = 14.0638(12)A, α = 69.437(2), β= 73.2890(10), γ = 78.5320(10)o, V = 1671.9(2) A^3, Z = 2, Dc = 1.449 g/cm^3, F(000) = 705,μ(MoK α) = 0.453 mm^-1, S = 1.053, R = 0.0491 and wR = 0.1367 for 5837 unique reflections(Rint =0.0208) with I 〉 2σ(I). Compound 2 belongs to the monoclicnic system, space group C2/c with a =15.199(3), b = 19.731(3), c = 21.537(5) ?, β = 105.228(3)o, V = 6232(2) A^3, Z = 8, Dc = 1.363g/cm^3, F(000) = 2648, μ(MoK α) = 0.475 mm^-1, S = 1.048, R = 0.0489 and wR = 0.1151 for 7414 unique reflections(Rint = 0.0425) with I 〉 2σ(I). Structural analyses reveal that complex 1 is a4-connected(44.62)-sql bilayer structure with binuclear [Mn2(COO)2] SBU, while complex 2 is a normally(3,5)-connected(42.67.8)(42.6)-3,5L2 monolayer. And the sheets interacted with the adjacent sheets through weak interactions, finally giving a stable three-dimensional(3D)supramolecule. Besides, the variable-temperature magnetic susceptibility measurement of complex1 was investigated. 展开更多
关键词 coordination polymer pyridine-benzene carboxylic acid manganese magnetic property bis(imidazole) linkers
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Syntheses,Crystal Structures,and Magnetic Properties of Cobalt(Ⅱ) Complexes with 1,1-Cyclohexanediacetic Acid 被引量:5
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作者 鞠丰阳 李云平 +1 位作者 李桂连 刘广臻 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第3期404-412,共9页
Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane ... Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane and bpe = 1,2-bis(4-pyridinyl)ethylene),were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis(TGA),and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square(4,4) grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given. 展开更多
关键词 1 1-cyclohexanediacetic acid hydrothermal synthesis cobalt(Ⅱ) complex magnetic properties
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Synthesis,Fluorescence and Magnetic Properties of a New Europium(Ⅲ) Complex Eu(L)3(Phen)2 被引量:2
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作者 谭雄文 李昶红 +1 位作者 李衡峰 杨颖群 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第1期170-174,共5页
A new europium(III) complex Eu(L)3(Phen)2(1) with 2-benzoylbenzoic acid(HL) and 1,10-phenanthroline(Phen) as ligands has been synthesized. Crystal data for the complex are as follows: monoclinic, space gr... A new europium(III) complex Eu(L)3(Phen)2(1) with 2-benzoylbenzoic acid(HL) and 1,10-phenanthroline(Phen) as ligands has been synthesized. Crystal data for the complex are as follows: monoclinic, space group P21/c, a = 2.2577(4), b = 1.23484(19), c = 1.8789(3) nm, β = 94.918(3)o, V = 5.2189(14) nm^3, Dc = 1.512 g/cm^3, Z = 4, μ(Mo Kα) = 1.269 mm^-1, F(000) = 2408, the final R = 0.0433 and w R = 0.1038. The Eu(III) ion is coordinated by nine atoms to give a single-capped square antiprism coordination geometry. 1 shows two intense fluorescence emission bands arising from the transitions of Eu^3+: ^5D0→^7F1(597 nm) and ^5D0→^7F2(615 nm) with an excitation wavelength of 396 nm. In addition, 1 displays antiferromagnetic property at low temperature. 展开更多
关键词 europium(Ⅲ) complex 2-benzoylbenzoic acid crystal structure fluorescent and magnetic properties
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Effect of x-alumina addition on H_2S oxidation properties of pure and modified y-alumina
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作者 Svetlana A.Yashnik Vadim V.Kuznetsov Zinfer R.Ismagilov 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第2期258-274,共17页
The influence of the textural and acidic properties ofγ‐Al2O3,(γ+χ)‐Al2O3,and?‐Al2O3on the catalytic activity,selectivity,and stability of direct H2S oxidation has been studied.A comparison of the H2S‐to‐S con... The influence of the textural and acidic properties ofγ‐Al2O3,(γ+χ)‐Al2O3,and?‐Al2O3on the catalytic activity,selectivity,and stability of direct H2S oxidation has been studied.A comparison of the H2S‐to‐S conversion effectiveness of aluminas with their acidic properties(identified by Fourier transform infrared spectroscopy and temperature programmed desorption of NH3)shows that H2S adsorption occurs predominantly on weak Lewis acid sites(LAS).γ‐Alumina samples containing aχ‐phase and/or modified Mg2+ions have a greater concentration of weak LAS and exhibit greater catalytic activity.When alumina is treated with a sulfuric acid solution,strong LAS appear and the number of LAS decreases significantly.Modification of alumina with hydrochloric acid has a limited effect on LAS strength.Weak LAS are retained and double in number compared to that present in the unmodified alumina,but the treated sample has Al?Cl bonds.Alumina samples modified by sulfate and chloride anions exhibit poor catalytic activity in H2S oxidation. 展开更多
关键词 ALUMINA χ‐Al2O3 Hydrogen sulfide oxidation acidic property Lewis acid sites Fourier transform infrared spectroscopy NH3‐temperature programmed desorption
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Preparation and Properties of Heat Resistant Polylactic Acid(PLA)/Nano-SiO2 Composite Filament 被引量:1
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作者 吴改红 刘淑强 +1 位作者 JIA Husheng DAI Jinming 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第1期164-171,共8页
In order to improve the thermal properties of polylactic acid(PLA) filament,nano-SiO_2 was applied to mix with PLA,then they were spun as composite filament by melt-spinning.The dispersion of nano SiO_2 and the frac... In order to improve the thermal properties of polylactic acid(PLA) filament,nano-SiO_2 was applied to mix with PLA,then they were spun as composite filament by melt-spinning.The dispersion of nano SiO_2 and the fracture surfaces of filaments were studied by scanning electron microscopy(SEM).The properties of composite filament,such as orientation degree,mechanical properties,and surface friction properties,were analyzed.The thermal performances of composite filament were analyzed by differential scanning calorimetry(DSC) and thermo gravimetric analysis(TGA).The results showed that the nano-SiO_2 modified by 5% KH-550 could disperse evenly and loosely in nano-scale,and 1 wt% and 3 wt% nano-SiO_2 dispersed throughout PLA evenly.As the quantity of nano-SiO_2 increased,the properties of composite filament,such as orientation degree,friction coefficient,thermal decomposition temperature,and glass transition temperature,increased more or less.The breaking tenacity increased when 1 wt% SiO_2 was added in PLA,but declined when 3 wt% SiO_2 was added. 展开更多
关键词 polylactic acid PLA composite filament nano-silicon dioxide(nano-SiO_2) thermal property
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Hydrothermal Synthesis,Crystal Structure and Properties of a Novel 3D Metal-organic Coordination Polymer with Helical Chains Based on 5-(Imidazol-1-ylmethyl)isophthalic Acid
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作者 李付安 杨维春 +1 位作者 苗许 李松田 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第3期421-427,共7页
A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethyl)isophthalic acid(H_2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillar... A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethyl)isophthalic acid(H_2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillary ligand,[Cd L(bpa)_(0.5)]_n(1),has been obtained under hydrothermal conditions and characterized by elemental analysis,powder X-ray diffraction(PXRD),IR,thermal gravimetric analyses(TGA) and single-crystal X-ray diffraction.It crystallizes in monoclinic,space group P2_1/c with a = 10.984(2),b = 10.1829(12),c = 17.782(3) A,β = 123.156(11)o,V = 1665.1(5) A^3,Z = 4,Mr = 448.72,Dc = 1.790 g/cm^3,Rint = 0.0871,F(000) = 892,the final R = 0.0687 and w R = 0.1294 for 2920 observed reflections(I 〉 2σ(I)).In complex 1,the L^2- anions connect Cd(Ⅱ) ions to form two-dimensional metal-organic layers(Cd_2L_2)n,in which the 1D helical chains(Cd-L)_n are alternately arranged in a right-and left-handed sequence.These layers are further linked to build a 3D network by the bpa ligand.In addtion,photoluminescent properties for 1 are also investigated. 展开更多
关键词 cadmium 5-(imidazol-1-ylmethyl)isophthalic acid PXRD luminescent properties
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SUIDIES ON SOME PROPERTIES AND CATALYSIS OF RARE EARTH HETEROPOLY ACIDS
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《Chemical Research in Chinese Universities》 SCIE CAS 1986年第1期93-96,共4页
INTRODUCTIONThough potassium salts of rare earth substituted silicotungsticacids were synthesized early in 1971 by R.D.Peacock etc.,sofar the reports about the application of the corresponding acidshave not been found... INTRODUCTIONThough potassium salts of rare earth substituted silicotungsticacids were synthesized early in 1971 by R.D.Peacock etc.,sofar the reports about the application of the corresponding acidshave not been found.We prepared fourteen rare earth substitutedsilicotungstic acids and determined their thermal stability,IRabsorption Spectra and x-ray diffraction spectra.Furthermore,thecatalytic activities of the fourteen heteropoly acids in acid cata-lytic reaction were investigated.Our experimental results demonstrated rare earth substituted silico-tungstic acids have very high catalytic activity in the reaction of 展开更多
关键词 SUIDIES ON SOME properties AND CATALYSIS OF RARE EARTH HETEROPOLY ACIDS
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Promoted effect of zinc–nickel bimetallic oxides supported on HZSM-5 catalysts in aromatization of methanol 被引量:8
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作者 Yanming Jia Junwen Wang +4 位作者 Kan Zhang Wei Feng Shibin Liu Chuanmin Ding Ping Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第3期540-548,共9页
Zn/ZSM-5(NZ2) and Zn/Ni/ZSM-5(NZ3) as the catalysts for methanol to aromatics(MTA) were synthesized by a simple ultrasonic impregnation. The textural and acid properties of all catalysts were characterized using... Zn/ZSM-5(NZ2) and Zn/Ni/ZSM-5(NZ3) as the catalysts for methanol to aromatics(MTA) were synthesized by a simple ultrasonic impregnation. The textural and acid properties of all catalysts were characterized using XRD, HRTEM, NH;-TPD, Py-IR, XPS, XRF and TG techniques. The XRD and HRTEM results showed that the basic zeolite structures were not affected much with the incorporation of Zn and Ni species. However, great changes have taken place in acid properties. The Py-IR and XPS results indicated that the Zn-Lewis acid sites(ZnOH;species), which have stronger interaction with the zeolite framework compared with ZnO species, were generated at the expense of B acid sites with the incorporation of zinc species. Moreover, the product analysis results showed that the incorporation of zinc species promoted the primary aromatization by enhancing the dehydroaromatization and suppressing the cracking and subsequent H-transfer reaction. Furthermore, the addition of Ni species well inhibited the loss of zinc species by converting partial ZnO species to ZnOH;species, and thus improved the aromatization activity and catalyst stability. The catalytic performance results showed that the NZ3 possess higher conversion of methanol in a longer time and lower average rate of coke formation compared with NZ2. In addition,the NZ3 also exhibited the highest yield of BTX as the reaction proceeds. 展开更多
关键词 Zn/Ni/ZSM-5 Acid properties METHANOL AROMATIZATION
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Controllably tailoring external surface sites of nanosheet HZSM-5 for maximizing light olefins in catalytic cracking of n-decane 被引量:1
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作者 Tiantian Zhu Hairui Liang +2 位作者 Bofeng Zhang Yajie Tian Guozhu Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期276-285,共10页
A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modificati... A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modification was found to passivate some external Br?nsted and Lewis acid sites by37.8%,in which Br?nsted acid sites(BAS)were found more easily sacrificed by breaking the surface Al AO bond of bridging hydroxyl groups and forming Si AOASi bonds.The selectivity of ZN-8 catalyst for light olefins(ethylene,propylene and butene)in n-decane catalytic cracking is up to 26%(450℃,WHSV=10.95 h^(-1)),which is ca.78%higher than that of parent one.The better performance was attributed to the appropriate external acid density in ZN-8,which inhibits bimolecular hydrogen transfer reaction of light olefins on the adjacent acid sites,resulting in more olefins,few coke precursors and thus an excellent catalytic stability. 展开更多
关键词 Nanosheet HZSM-5 Acid properties Surface modification Catalysis DEACTIVATION FIXED-BED
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Effects of total replacement of corn silage with sorghum silage on milk yield,composition, and quality 被引量:7
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作者 M.Cattani N.Guzzo +1 位作者 R.Mantovani L.Bailoni 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第3期652-659,共8页
Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments cond... Background: In the last years, difficulties occurring in corn cultivation(i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield.However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition(i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese.This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage.Results: The sorghum diet reduced milk yield(P = 0.043) but not 4% fat corrected milk(P = 0.85). Feeding sorghum silage did not influence milk contents of protein(P = 0.07) and lactose(P = 0.65), and increased fat content(P = 0.024).No differences emerged for milk concentrations of saturated(P = 0.61) and monounsaturated fatty acids(P = 0.50),whereas polyunsaturated fatty acids were lower(P 〈 0.001) for the sorghum diet. Concentrations of n-6(P 〈 0.001) and n-3 fatty acids(P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the "a30"(the curd firmness, expressed in mm, 30 min after rennet addition), that was lower(P = 0.042) for the sorghum diet.Conclusions: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets. 展开更多
关键词 Dairy cows Forage sorghum silage Mean particle size Milk coagulation properties Milk fatty acid profile
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Molecular Structure and Theoretical Thermodynamic Study of Folic Acid Based on the Computational Approach 被引量:3
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作者 Shahla Hamedani Hossein Aghaie 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第9期1307-1316,共10页
In our previous work, we studied the interaction of folic acid, FA, molecule with single- walled carbon nanotube and the related binding energies with other related parameters. Now, in order to extend our study with r... In our previous work, we studied the interaction of folic acid, FA, molecule with single- walled carbon nanotube and the related binding energies with other related parameters. Now, in order to extend our study with respect to the other structural properties of folic acid molecule and its thermodynamic properties, we optimized the structures of both neutral and zwitteronic forms of this molecule by using the DFT/B3LYP method in the gas phase and then in different solvents. In addition, the electronic properties, such as the molecular orbital study (HOMO, LUMO, PDOS, and TDOS) and geometrical structure, were investigated by the above-mentioned method with 6-3 l G(d) basis set. The thermodynamic properties of both neutral and zwitterionic forms of the FA molecule at different temperature have been calculated. Natural bond orbital (NBO) analysis has been done to study the stability of the molecule arising from charge delocalization. 展开更多
关键词 folic acid thermodynamic properties DFT NBO
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Synthesis,Structure and Photoluminescence of a New Pb(Ⅱ)Coordination Polymer[Pb(1,4-chdc)(L)]n·nH2O Based on a Flexible 1,4-Cyclohexanedicarboxylic Acid 被引量:1
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作者 吴振东 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第5期753-757,共5页
A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f]... A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182(8), b = 11.3249(10), c = 12.7326(12) A, α = 77.897(2), β = 81.644(2), γ = 84.491(2)°, V = 1269.0(2) A^3, Z = 2, C_(27)H_(24)FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F(000) = 690, μ(MoKa) = 6.701 mm^(-1), R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb(Ⅱ) atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied. 展开更多
关键词 crystal structure coordination polymer 1 4-cyclohexanedicarboxylic acid luminescent property
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Two Metal Ion-controlled Zn(Ⅱ)/Cd(Ⅱ) Coordination Polymers Based on 1,3,5-Benzenetricarboxylic Acid 被引量:2
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作者 王记江 曹壮 +4 位作者 唐龙 王潇 侯向阳 鞠萍 张恩生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第10期1617-1623,共7页
Two new coordination polymers {[Zn(Hbtc)(bpyb)]·H2O}n(1) and {[Cd(Hbtc)-(bpyb)(1.5)]·0.5 bpyb}n(2)(H3btc = 1,3,5-benzenetricarboxylic acid, bpyb = 1,4-bis(4-pyridyl)benzene) have been synth... Two new coordination polymers {[Zn(Hbtc)(bpyb)]·H2O}n(1) and {[Cd(Hbtc)-(bpyb)(1.5)]·0.5 bpyb}n(2)(H3btc = 1,3,5-benzenetricarboxylic acid, bpyb = 1,4-bis(4-pyridyl)benzene) have been synthesized under hydrothermal conditions. The two compounds were characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Compound 1 displays a 2-fold interpenetrating 3D supramolecular architecture through O–H…N/O hydrogen bonds and π-π stacking interactions. Compound 2 exhibits a 2D→3D polycatenated structure, which is further stabilized by O–H…N hydrogen bonds. The results indicate that the metal ion has significant effects on the formation and structure of the resulted coordination polymers. Furthermore, thermal stability and photoluminescent properties of 1 and 2 are also discussed in detail. 展开更多
关键词 Zn(Ⅱ)/Cd(Ⅱ) 1 3 5-benzenetricarboxylic acid photoluminescent properties
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Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ)Coordination Polymer Based on Terephthalic Acid 被引量:1
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作者 林小英 杨攀 +2 位作者 陈君 刘明华 林诚 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期61-68,共8页
Solvothermal reaction of Pb(NO3)2·6H2O with rigid linear ligand terephthalic acid(H2pta) in N,N-dimethylformamide(DMF) produced a new three-dimensional(3D) lead(Ⅱ)coordination polymer[Pb2(pta)1.5(μ... Solvothermal reaction of Pb(NO3)2·6H2O with rigid linear ligand terephthalic acid(H2pta) in N,N-dimethylformamide(DMF) produced a new three-dimensional(3D) lead(Ⅱ)coordination polymer[Pb2(pta)1.5(μ4-OH)(DMF)]n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ4-OH bridges the nearby lead(Ⅱ) ions into an infinite one-dimensional(1D) chain,and then the organic ligand pta^2- joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta^2- and the p orbitals of the Pb^2+ centers. 展开更多
关键词 solvothermal synthesis lead(Ⅱ) coordination polymer terephthalic acid photoluminescence property crystal structure
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Synthesis and Characterization of a Two-dimensional Cadmium(Ⅱ) Metal Organic Framework with Fes Topology 被引量:1
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作者 李欢欢 刘利 +1 位作者 明春伦 崔广华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第7期1050-1056,共7页
A new Cd(II) coordination polymer, {[Cd(Hnbta)(L)]·H2O}n (L = 1,4-bis(5,6-dime- thylbenzimidazol-l-yl)butane), H3nbta= 5-nitrobenzene-1,2,3-tricarboxylic acid), has been hydro -thermally synthesized an... A new Cd(II) coordination polymer, {[Cd(Hnbta)(L)]·H2O}n (L = 1,4-bis(5,6-dime- thylbenzimidazol-l-yl)butane), H3nbta= 5-nitrobenzene-1,2,3-tricarboxylic acid), has been hydro -thermally synthesized and characterized by elemental analyses, IR, XRPD, and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/n with a = 17.3056(13), b = 11.0114(9), c = 17.7484(14) A,β= 117.3640(10)°, V = 3003.7(4) A3, Z = 4, C31H31CdN5O9, Mr = 730.01, Dc = 1.614 g/cm3, μ= 0.792 mm·-1and F(000) = 1488. The cadmium(II) ions are bridged by Hnbta2- to generate a two-dimensional metal organic framework with fes topology. In addition, the thermal stability and fluorescence properties of the complex were also studied. 展开更多
关键词 Cd(II) complex crystal structure fluorescence property 5-nitrobenzene-1 2 3-tricarboxylic acid
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Spectral,Thermal and Structural Studies of Two 3D Coordination Polymers Based on Tetracarboxylic Ligand 被引量:1
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作者 梁丽丽 徐磊 +2 位作者 李培 陈飞剑 薛洪宝 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期85-92,共8页
Two new coordination polymers,[M6L3(DMA)3(H2O)](M=Zn for 1,Cu for 2,L=tetrakis[3-(carboxyphenyl)oxamethyl]methane acid,DMA = N,N-dimethylacetamide) have been solvothermally synthesized. Single-crystal X-ray di... Two new coordination polymers,[M6L3(DMA)3(H2O)](M=Zn for 1,Cu for 2,L=tetrakis[3-(carboxyphenyl)oxamethyl]methane acid,DMA = N,N-dimethylacetamide) have been solvothermally synthesized. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 are isostructural and crystallize in the trigonal space group R. The asymmetrical unit contains two metal ions,one L^4- ligand and two coordinated DMA molecules. The metal ions are connected through six aromatic rings into a linear trimetallic zinc building unit. The whole structure is connected through tetrehedral ligand and the trimetallic building units to form a 4,6-connected framework of the toc topology. Compounds 1 and 2 are further studied by IR spectroscopy,thermogravimetric analyses and PXRD. The solid-state UV-Vis and photoluminescent properties of compounds 1 are also investigated. 展开更多
关键词 tetrakis[3-(carboxyphenyl)oxamethyl]methane acid cupper complex cadmium complex luminescent property
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A Pair of 3D Homochiral Coordination Polymers with Open Channels Constructed by Lactic Acid Derivative Ligands and In-situ Formed Anions 被引量:1
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作者 徐中轩 马钰璐 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第4期671-678,共8页
With the help of in-situ formed CH_3COO- anion, a pair of 3D homochiral coordination polymers with open channels were constructed by the assembly of lactic acid derivative ligands, 1.4-DIB ligands and Cd(II) ions, n... With the help of in-situ formed CH_3COO- anion, a pair of 3D homochiral coordination polymers with open channels were constructed by the assembly of lactic acid derivative ligands, 1.4-DIB ligands and Cd(II) ions, namely [Cd3((R)-CIA)2(CH3CO2)_2(1.4-DIB)2(H2O)2]·x(Guest)(1-D) and [Cd3((S)-CIA)2(CH3CO2)2(1.4-DIB)2(H2O)2]·x(Guest)(1-L). They contain 1D interesting ladder-like Cd-(R)-CIA(3-) chains and exhibit SHG-active behavior and photoluminescent property. 展开更多
关键词 homochiral coordination polymers lactic acid derivative ligand open channel SHG-active behavior photoluminescent property
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