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Surface plasmon resonance-induced visible-light photocatalytic performance of silver/silver molybdate composites 被引量:5
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作者 杨祥龙 王尹 +3 位作者 徐骁 瞿阳 丁星 陈浩 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第2期260-269,共10页
Novel silver/silver molybdate(Ag/Ag2MoO4) composites with surface plasmon resonance(SPR)-enhanced photocatalytic performance were successfully fabricated via a facile one-pot hydrothermal route with the presence o... Novel silver/silver molybdate(Ag/Ag2MoO4) composites with surface plasmon resonance(SPR)-enhanced photocatalytic performance were successfully fabricated via a facile one-pot hydrothermal route with the presence of sodium dodecyl sulfate(SDS) in this study.The as prepared silver/silver molybdate(Ag/Ag2MoO4) composites were systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and ultraviolet-visible diffuse reflectance absorption spectroscopy(DRS) in order to investigate their crystal structure,morphology and optical property as well.The photocatalytic activities of the composites were subsequently evaluated by their ability to degrade rhodamine B(RhB) under visible-light irradiation.Varies of controlled experiments were then carefully operated to gain a deep insight into the assembling of Ag/Ag2MoO4composites.It was found that preparation conditions such as pH,reaction time,and the amount of surfactant played important roles in the formation of composites with octahedral microstructures.And the composite obtained at 160 ℃ using 0.5 g of sodium dodecyl sulfate exhibited the highest photocatalytic performance under visible-light irradiation.Capture experiments were also conducted to clarify the function of different active species generated on the surface of Ag/Ag2MoO4during the photocatalytic process,in which both holes and ·OH radicals were found to play crucial role in photocatalytic removal of RhB under visible light irradiation.A possible photocatalytic mechanism of Ag/Ag2MoO4 was finally proposed on the basis of all the results to explain the higher photocatalytic activity of the octahedral Ag/Ag2MoO4 composites.It was inferred that the photoinduced "hot" electrons can quickly transfer from the Ag NPs to the conduction band of Ag2MoO4 and react with oxygen and H2O to generate a large quality of active radicals such as ·OH and ·O2^- because of the SPR effects.Besides,this SPR effects of Ag nanoparticles deposited on the surface of Ag2MoO4 can not only dramatically amplify its light absorption,especially in the visible region,but also promote the separation of photoexcited electron-hole pairs and effectively decrease electron-hole recombination. 展开更多
关键词 SILVER Silver molybdate Sodium dodecyl sulfate Photocatalytic activity Surface plasmon resonance Rhodamine B
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Role and Mechanism of Action of Exogenous Salicylic Acid and Sodium Molybdate in Improving Cold Tolerance of Bougainvillea glabra 被引量:6
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作者 Yongfu ZHANG Yanfen NIU Shengjing PENG 《Agricultural Biotechnology》 CAS 2018年第6期35-40,共6页
This study was conducted to comprehensively evaluate the effects of salicylic acid and sodium molybdate on cold tolerance of an ornamental plant Bougainvillea glabra and to provide a theoretical guidance for landscape... This study was conducted to comprehensively evaluate the effects of salicylic acid and sodium molybdate on cold tolerance of an ornamental plant Bougainvillea glabra and to provide a theoretical guidance for landscape maintenance.B.glabra plants were treated with 0.5 mmol/L salicylic acid and 2.0 μmol/L alone or in combination,and then exposed to low temperature stress before physiological indices were measured.The results showed that all salicylic acid and sodium molybdate treatments reduced the relative conductivity and malondialdehyde( MDA) content of B.glabra to varying extents under the stress of low temperature,and more significant effect was achieved by using the two agents in combination.Oxygen free radicals production rate increased with decreasing temperature from 20 to 6 ℃,but declined with temperature decreasing from 3 to-3 ℃.The SOD activity of the control( CK) was significantly lower than that of other treatments at 0 and-3 ℃.The treatments with salicylic acid and sodium molybdate alone and in combination increased POD activity of B.glabra plants,especially at 0 ℃,as the POD activity of treatments T1,T2 and T3 was significantly higher than that of CK at 0 ℃.In addition,under low temperature stress,the contents of soluble sugar,starch and proline increased initially and decreased subsequently with temperature decreasing.The soluble sugar content at 3 ℃,starch and proline contents at 0 and-3 ℃ in treatments with salicylic acid and sodium molybdate alone and in combination were significantly higher than those of CK.All above results proved that salicylic acid and sodium molybdate are able to improve cold tolerance of B.glabra,and better effect can be achieved by using them together. 展开更多
关键词 BOUGAINviLLEA glabra Salicylic acid SODIUM molybdate Low temperature stress Cold TOLERANCE PHYSIOLOGICAL mechanism
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Characterization and photoluminescence properties of ultrafine copper molybdate(α-CuMoO_4) powders prepared via a combustion-like process 被引量:2
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作者 Mohamed Benchikhi Rachida El Ouatib +2 位作者 Sophie Guillemet-Fritsch Lahcen Er-Rakho Bernard Durand 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第11期1340-1345,共6页
We report a simple method for preparing copper(II) molybdate(CuMoO_4) powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing... We report a simple method for preparing copper(II) molybdate(CuMoO_4) powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the(CuMo)-precursor gel was studied by thermogravimetry–differential thermal analysis(TG–DTA), Fourier transform infrared spectroscopy(FTIR), and X-ray diffraction(XRD). We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^(2-)] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size. 展开更多
关键词 copper molybdate chemical synthesis photoluminescence Jahn-Teller effect
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Growth and corrosion behavior of molybdate passivation film on hot dip galvanized steel 被引量:12
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作者 卢锦堂 孔纲 +2 位作者 陈锦虹 许乔瑜 眭润舟 《中国有色金属学会会刊:英文版》 CSCD 2003年第1期145-148,共4页
Hot dip galvanized steel sheets were passivated by molybdate aqueous solution containing 10 g/L Na 2MoO 4·2H 2O, and the growth behavior and corrosion resistance of the passivation film were investigated. In the ... Hot dip galvanized steel sheets were passivated by molybdate aqueous solution containing 10 g/L Na 2MoO 4·2H 2O, and the growth behavior and corrosion resistance of the passivation film were investigated. In the initial stage of passivation, the mass gain of film increases with passivation time proportionally. The film grows up more quickly and is apt to cracking at grain boundaries of zinc, then the cracks spread gradually on the whole surface of the film, and eventually the film will flake off with the increasing of film thickness. XPS results indicate that Mo compounds are present in Mo(Ⅵ) state on the surface of the film, and Mo(Ⅵ) and Mo(Ⅳ) states inside the film. NSS test shows that, the corrosion resistance of the passivation film decreases as the cracks occur, but in AASS test, the thicker the film is, the better the corrosion resistance is, the cracks of film have little effect on the corrosion resistance. 展开更多
关键词 耐腐蚀性 钼酸盐钝化薄膜 热浸镀锌钢 生长
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Effect of Molybdate Ions on the Corrosion Behaviour of Ti Alloys
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作者 Magda.M.A.Gad, Kamal.E.Mohamed and Abdelwahab A.El-Sayed (Metallurgy Dept., Materials Division, Atomic Energy Authority, Cairo, Egypt) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第1期45-49,共5页
Titanium alloys are extensively used in power, chemical and petroleum industries as constructional materials for vessels and heat transfer tubes. Moreover they are candidate materials for nuclear waste disposal. These... Titanium alloys are extensively used in power, chemical and petroleum industries as constructional materials for vessels and heat transfer tubes. Moreover they are candidate materials for nuclear waste disposal. These alloys have superior resistance to localized forms of corrosion compared to stainless steels and Ni-base alloys. However, this resistance is not as remarkable in crevice corrosion conditions in some aggressive media. Electrochemical corrosion tests were conducted on two ASTM Ti grades namely, Ti-2 and Ti-12 in extremely low pH acidic environment. Results indicated that Ti-2 has less resistance to both general and crevice corrosion attack than Ti-12. Both alloys possess better resistance to general corrosion than to crevice corrosion. Also, results showed that the molybdate addition improves remarkably the resistance of Ti-2 to both types of attack. The increase of molybdate ions concentration from 0.03 mol/L to 0.15 mol/L made Ti-2 to be as resistant as, or somewhat higher than, Ti-12. The elecrochemical findings were further supplemented by optical examination of the corroded surface. 展开更多
关键词 TI MO Effect of molybdate Ions on the Corrosion Behaviour of Ti Alloys
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Solid and Solution Structural Studies of Dimeric and Tetrameric Molybdenum(VI) Malate Complexes 被引量:1
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作者 张荣华 周朝晖 万惠霖 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第8期919-926,共8页
Reactions of potassium molybdate with racemic malic acid (H3mal = C4H6O5) result in the isolation of two mesomeric molybdenum malate complexes K8[(MoO2)2O(R-mal)2][(MoO2)2O(Smal)2]-4H2O 1 and (Him)2K6[(M... Reactions of potassium molybdate with racemic malic acid (H3mal = C4H6O5) result in the isolation of two mesomeric molybdenum malate complexes K8[(MoO2)2O(R-mal)2][(MoO2)2O(Smal)2]-4H2O 1 and (Him)2K6[(MoO2)4O3(R-mal)2][(MoOE)4O3(S-mal)2]-8H2O 2. Complex 1 belongs to the monoclinic system, space group C2/c with a = 14.8637(3), b = 6.9544(1), c = 19.6783(5)A, β = 100.081(2)°, V = 2002.70(7) A^3, Mr = 1452.88, Z = 2, F(000) = 1416, T = 173 K, Dc = 2.409 g/cm3, fl(MoKa') = 2.167, R = 0.0283 and wR = 0.0733.2 is of triclinic system, space group P1^- with a = 8.7707(2), b = 9.3310(3), c = 17.9093(7)A, α= 83.781(3), β = 85.626(2), y= 84.822(2)°, V = 1447.84(8)A^3, Mr = 2160.68, Z = 1, F(000) = 1048, T = 173 K, Dc = 2.478 g/cm^3,μ(MoKα) = 2.230, R = 0.0234 and wR = 0.0584.1 is the first isolated dinuclear molybdenum(VI) malato complex in 1:1 molar ratio. The molybdenum atoms in the two complexes are six-coordinated in an approximately octahedral geometry. Two malates coordinate tridentately with the Mo atom via their α-alkoxy, α-carboxy and α-carboxy groups in 1 and 2. β-Carboxy group in 2 further links with the other two Mo atoms to give a tetrameric unit. The solution ^1H and ^13C NMR spectra indicate that dimeric malate molybdenum in 1 dissociates partly in solution and exists in an equilibrium with tetrameric species, while 2 is stable and retains its tetrameric structure without any dissociation. 展开更多
关键词 molybdate(vi) MALATE NITROGENASE crystal structure NMR
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海藻酸钠基凝胶吸附材料对Cr(VI)吸附性能研究 被引量:1
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作者 王红菊 《广州化工》 CAS 2024年第3期50-52,共3页
海藻酸钠(SA)是一种天然生物质材料,其来源广、价格低,聚乙烯亚胺是一种含有氨基(-NH_(2))的水溶性高分子聚合物,螯合重金属离子能力强,众多研究者将二者结合其制备成吸附剂去除水溶液中的金属离子。本研究以海藻酸钠为基体,加入碳酸钙... 海藻酸钠(SA)是一种天然生物质材料,其来源广、价格低,聚乙烯亚胺是一种含有氨基(-NH_(2))的水溶性高分子聚合物,螯合重金属离子能力强,众多研究者将二者结合其制备成吸附剂去除水溶液中的金属离子。本研究以海藻酸钠为基体,加入碳酸钙和聚乙烯亚胺,以戊二醛为交联剂,经冷冻干燥后形成吸附较好的海藻酸钠-聚乙烯亚胺吸附材料。采用吸附实验研究了材料对水中Cr(VI)的吸附性能,并研究初始浓度、溶液pH、吸附时间、吸附剂用量等对吸附效果的影响。实验结果表明:在Cr(VI)溶液初始浓度为15 mg/L、吸附剂用量0.4 g、吸附时间200 min,吸附温度为313 K时,Cr(VI)去除率达90%以上。 展开更多
关键词 海藻酸钠 CR(vi) 吸附 性能
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Luminescent Properties of Samarium Ion in Calcium Molybdate 被引量:8
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作者 胡运生 庄卫东 叶红齐 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第6期821-824,共4页
Trivalent samarium ion (Sm^(3+)) activated calcium molybdate (CaMoO_4) phosphor was prepared by solid-state reaction in air. The XRD pattern of the powder CaMoO_4∶Sm shows that the CaMoO_4∶Sm single phase is develop... Trivalent samarium ion (Sm^(3+)) activated calcium molybdate (CaMoO_4) phosphor was prepared by solid-state reaction in air. The XRD pattern of the powder CaMoO_4∶Sm shows that the CaMoO_4∶Sm single phase is developed fully through our preparation procedure. The excitation spectrum of CaMoO_4∶Sm is composed of a broad absorption of host and some sharp lines of the f-f transition absorption of Sm^(3+). Illustrated in photoluminescence spectrum, CaMoO_4 doped with Sm^(3+) displays orange red emission that is ascribed to the inner 4f^5 electron transitions ~6H_(7/2)(orange)and ~6H_(9/2)(red)of Sm^(3+). Different from the sites of Sm^(3+) in CdWO_4, the Sm^(3+) ions substitute for the Ca^(2+) and form only one type emission center in the CaMoO_4 crystal lattice. 展开更多
关键词 PHOTOLUMINESCENCE calcium molybdate samarium rare earths
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Synthesis and Structure Investigation of a Transition Metal Ion Bridging Bis(diphosphopentamolybdates),[H_2BIIM]_3[HBIIM]_4[Mn(H_2O)_4(P_2Mo_5O_(23))_2]·7H_2O 被引量:6
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作者 魏林恒 王子梁 +1 位作者 赵俊伟 王敬平 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第5期784-788,共5页
A novel transition metal ion bridging bis(diphosphopentamolybdates) has been synthesized and characterized by elemental analysis,IR spectrum,UV spectrum and single-crystal X-ray diffraction.The single-crystal struct... A novel transition metal ion bridging bis(diphosphopentamolybdates) has been synthesized and characterized by elemental analysis,IR spectrum,UV spectrum and single-crystal X-ray diffraction.The single-crystal structure analysis shows that the compound consists of seven charge-compensating 2,2'-biimidazole cations (BIIM=2,2'-biimidazole) and one dumbbell-like [Mn(H2O)4(P2Mo5O23)2]10-heteropolyanion which is constructed by two [P2Mo5O23]6-clusters bridged through one [Mn(H2O)4]2+ cation. 展开更多
关键词 POLYOXOMETALATE molybdate crystal structure dumbbell-like PHOSPHATE
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Synergistic Corrosion Inhibition Effect of Molybdate and Phosphate Ions for Anodic Oxidation Film Formed on 2024 Aluminum Alloy 被引量:5
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作者 王文博 DONG Peng +2 位作者 WANG Haiyun 程杰 刘胜利 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第2期426-432,共7页
In order to effectively improve the corrosion resistance of aluminum alloys, anodic oxidation technique was used to generate the oxide film. We investigated the influences of two inorganic corrosion inhibitors(ammoniu... In order to effectively improve the corrosion resistance of aluminum alloys, anodic oxidation technique was used to generate the oxide film. We investigated the influences of two inorganic corrosion inhibitors(ammonium dihydrogen phosphate and sodium molybdate) on the corrosion resistance of anodic oxidation films on 2024 aluminum alloy, and studied the synergistic effect of two corrosion inhibitors. The corrosion resistance of anodic oxidation film in 3.5 wt% NaCl solution was evaluated by electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization curves. Results show that, after adding the single ammonium dihydrogen phosphate or sodium molybdate of 0.01 M to oxalic acid electrolyte, inhibition efficiencies of the anodized samples are 10% and 47%, respectively. However, in the presence of two inhibitors with the same concentration of 0.01 M, inhibition efficiency can be as high as 92%. Therefore, we observed the significantly synergistic corrosion inhibition effect of molybdate and phosphate ions for anodic oxidation film formed on 2024 aluminum alloy. 展开更多
关键词 anodic oxidation technique CORROSION AMMONIUM DIHYDROGEN PHOSPHATE sodium molybdate SYNERGISTIC effect
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Removal of tungsten and vanadium from molybdate solutions using ion exchange resin 被引量:14
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作者 Xian-zheng ZHU Guang-sheng HUO +1 位作者 Jie NI Qiong SONG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第12期2727-2732,共6页
The removal of tungsten(W)and vanadium(V)from molybdate solutions was studied using the poly hydroxyl chelating resin D403in batch and column experiments.The batch experiments indicated that tungsten and vanadium coul... The removal of tungsten(W)and vanadium(V)from molybdate solutions was studied using the poly hydroxyl chelating resin D403in batch and column experiments.The batch experiments indicated that tungsten and vanadium could be preferentially adsorbed by the D403resin for4h in molybdate solution at a pH of approximately9.25.Separation factors,αVMo andαWMo,wereabove45and18,respectively,when the molar ratios of Mo/V and Mo/W in the solution exceeded40.Elution tests illustrated that vanadium and tungsten could be easily eluted from the resin with1mol/L sodium hydroxide solution in only1h.To further explore the sorption mechanism of the resin,the experimental equilibrium isotherm data of the three metals fitted well with the Freundlich model.The column experiments confirmed the adaptability of the D403resin in the production of sodium molybdate with a removal rate of tungsten surpassing90%and that of vanadium of99.4%. 展开更多
关键词 TUNGSTEN VANADIUM REMOVAL ion exchange molybdate
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应用型背景下标志与VI设计课程实施课程思政的路径研究
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作者 任静莉 《美术教育研究》 2024年第10期123-125,共3页
全面推进课程思政建设是落实立德树人根本任务的战略举措。为适应新时代对课程思政高质量发展的要求,该文基于高校“三全育人”工作需求,在应用型背景下,探索课程思政元素有机融入艺术设计类专业课程的路径。针对标志与VI设计课程,首先... 全面推进课程思政建设是落实立德树人根本任务的战略举措。为适应新时代对课程思政高质量发展的要求,该文基于高校“三全育人”工作需求,在应用型背景下,探索课程思政元素有机融入艺术设计类专业课程的路径。针对标志与VI设计课程,首先根据神经语言程序学者罗伯特·迪尔茨关于人的认知的六个层次理论,设计课程思政元素体系,进而通过详细解读和挖掘六种层次描述课程思政元素体系的设计思路,最后提出从五个讲授部分和三个实践部分,在课程实施过程中融入课程思政元素的具体策略和路径,以期促进艺术设计类专业教学与课程思政有机融合,充分发挥课程思政在高校艺术设计类专业课程中的育人作用,为标志与VI设计课程的思政教学设计与教学改革提供参考。 展开更多
关键词 标志与vi设计 课程思政
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Synthesis and Crystal Structure of Binuclear Oxomolybdenum(VI) Complex with Both o-Mercaptophenolate 被引量:4
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作者 WANG Xiu-Jian CHEN Zhen-Feng LIANG Hong(Department of Chemistry and Chemical Industry,Guangxi Normal University, Guilin, 541004)YU Kai-Bei(Chengdu Center of Analysis and Measurememt,the Chinese Academy of Scicnces, Chengdu 610041) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1997年第5期403-406,共4页
The complex (Bu4N) 2 [Mo2O5 (mp)2] was synthesized by the reactionof (Bu4N)2[Mo8O26] with H2mp (H2mp=o-mercaptophenol) in methanol. The molecular formula is C44H80Mo2N2O7S2, M.=1005.10. The complex is crystallized in ... The complex (Bu4N) 2 [Mo2O5 (mp)2] was synthesized by the reactionof (Bu4N)2[Mo8O26] with H2mp (H2mp=o-mercaptophenol) in methanol. The molecular formula is C44H80Mo2N2O7S2, M.=1005.10. The complex is crystallized in monoclinic, space group P21/n with unit cell parameters, a = 17. 829 (2) A, b= 13. 759 (2 )A,c= 21. 974(2) A, g=105. 386(8)°, V= 5197. 4(1) , Dc= 1. 285 g/cm3, Z=4,λ(MoKa) =0. 71073 , μ=0. 607 mm-1,F(000) = 2120, final R=0.0348 and wR=0. 0741 for 4912 independent observed reflections (FM>4σ(Fo) ). Two MoO5S units inthe complex molecule exhibits the con facial distorted bioctahedral geometry and possesses an approximate C2 symmetry. 展开更多
关键词 CRYSTAL structure molybdENUM (vi) COMPLEX o-mercaptophenol
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Synthesis and Properties of Eu_(3+) Activated Strontium Molybdate Phosphor 被引量:3
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作者 李旭 杨志平 +3 位作者 关丽 郭庆林 怀素芳 李盼来 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第6期706-709,共4页
In order to prepare fluorescent material for white Light Emitting Diodes (LEDs), a new Eu^3+ activated molybdate phosphor SrMoO4 was fabricated with solid-state method. X-ray diffraction (XRD) showed that the dop... In order to prepare fluorescent material for white Light Emitting Diodes (LEDs), a new Eu^3+ activated molybdate phosphor SrMoO4 was fabricated with solid-state method. X-ray diffraction (XRD) showed that the doping of trivalent europium ion reduced the lattice parameters. The excitation and emission spectra indicated that this phosphor could be excited effectively by the visible light, and then emitted red light with the peaks located at 616 and 624 nm. The influence of Eu^3+ concentration on the luminescent properties of Eu^3+ doped SrMoO4 was investigated and the 25% (mole fraction) was the appropriate molar concentration. The reaction time and temperature had obvious effect on the luminescent properties. The luminescent intensity reached the strongest when it was sintered at 800 ℃ for 3 h. 展开更多
关键词 white light emitting diodes (WLED) red phosphor molybdate XRD luminescent intensity rare earths
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Tungsten removal from molybdate solutions using chelating ion-exchange resin:Equilibrium adsorption isotherm and kinetics 被引量:3
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作者 朱先正 霍广生 +1 位作者 倪捷 宋琼 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第5期1052-1057,共6页
The equilibrium adsorption isotherm and kinetic of the sorption process for W and Mo on macro chelating resin D403 were investigated on single Na2 Mo O4 and Na2WO4 solutions.The sorption isotherm results show that the... The equilibrium adsorption isotherm and kinetic of the sorption process for W and Mo on macro chelating resin D403 were investigated on single Na2 Mo O4 and Na2WO4 solutions.The sorption isotherm results show that the adsorption process of W obeys the Freundlich model very well whereas the exchange process with Mo approximately follows the Henry model.The kinetic experiments show that the intraparticle diffusion process was the rate-determining step for W sorption on the resin,and the corresponding activation energy is calculated to be 21.976 k J/mol. 展开更多
关键词 TUNGSTEN molybdate ion-exchange resin isotherms KINETICS
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Leaching kinetics of calcium molybdate with hydrochloric acid in presence of phosphoric acid 被引量:5
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作者 Wen-juan ZHANG Cheng-yan WANG Bao-zhong MA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第4期859-867,共9页
Calcium molybdate(CaMoO4)is the main component of powellite and is a predominant intermediate in the pyrometallurgical and hydrometallurgical process of molybdenum.The extraction of Mo from CaMoO4 by a combination of ... Calcium molybdate(CaMoO4)is the main component of powellite and is a predominant intermediate in the pyrometallurgical and hydrometallurgical process of molybdenum.The extraction of Mo from CaMoO4 by a combination of phosphoric acid and hydrochloric acid was investigated.For further understanding of the leaching mechanism,the effects of five key factors were studied to describe the leaching kinetics.The results indicated that the dissolution rate of CaMoO4 was independent of the stirring speed.Mo extraction significantly increased with increasing HCl concentration and temperature,but decreased with increasing particle size.A shrinking core model with surface chemical reaction was found to withstand the dissolution of CaMoO4.The apparent activation energy was calculated to be 70.879 kJ/mol,and a semi-empirical equation was derived for the rate of reaction. 展开更多
关键词 calcium molybdate leaching kinetics phosphoric acid hydrochloric acid
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Preparations of Pure Alkaline Earth Molybdate Phases from Single Molecular Precursors 被引量:1
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作者 JIANGYa-qi ZHAOHong +3 位作者 FANGZhi-min WANHui-lin XIONGMing ZHOUZhao-hui 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第6期675-680,共6页
The pure phases of alkaline earth molybdates MMoO 4, where M=Mg, Ca, Sr or Ba, were synthesized via the calcination of the related citrato oxomolybdate complexes. The mixed metal oxides can be highly dispersed at the... The pure phases of alkaline earth molybdates MMoO 4, where M=Mg, Ca, Sr or Ba, were synthesized via the calcination of the related citrato oxomolybdate complexes. The mixed metal oxides can be highly dispersed at the atomic level due to the existence of uniform citrato oxomolybdenum precursors in definite composition. The complexing effect helps to produce the fine-grained oxides with particle size in the ultrafine scale(<100 nm) at heat-treatment temperatures below 500 ℃. The structures of the precursor complexes and the finally heat-treated particles were studied by means of IR, XRD, DSC, DTA and TG techniques. The morphologies of the particles were observed by using the SEM technique. The average particle sizes were calculated to be in the range of 30_50 nm based on X-ray diffraction line-broadening and SEM images, indicating the poor conglomeration of crystallite at low temperatures. 展开更多
关键词 Alkaline earth molybdate Citrate complexes Pechini process CATALYST Thermal decomposition
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Study on Sulfidation Degree and Morphology of MoS_2 Catalyst Derived from Various Molybdate Precursors 被引量:4
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作者 Zhang Le Li Mingfeng Nie Hong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2014年第2期1-7,共7页
The MoS_2 catalysts were prepared from various molybdate precursors including inorganic and organic molybdate compounds. The sulfidation degree and morphology of active phases of MoS_2 activated by various molybdate p... The MoS_2 catalysts were prepared from various molybdate precursors including inorganic and organic molybdate compounds. The sulfidation degree and morphology of active phases of MoS_2 activated by various molybdate precursors in H_2S/H_2 stream at different temperatures were studied by X-ray photoelectron spectroscopy(XPS) and high-resolution transmission electron microscopy(HRTEM). The organic molybdate precursors lead to MoS_2 catalysts with higher sulfidation degree and smaller active phases to demonstrate higher catalytic activity during hydrodesulfurizaiton(HDS) of 4,6-DMDBT. 展开更多
关键词 MOS2 molybdate precursors sulfidation degree MORPHOLOGY
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Mechanism of MoO2 electrodeposition from ammonium molybdate solution 被引量:3
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作者 Hua-zhen CAO Cheng-jian TONG +1 位作者 Hui-bin ZHANG Guo-qu ZHENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第8期1744-1752,共9页
A mechanism study on MoO2 electrodeposition from ammonium molybdate solution was presented via linear sweep voltammetry,species distribution diagram,Raman spectra,Fourier transform infrared spectrometry and X-ray diff... A mechanism study on MoO2 electrodeposition from ammonium molybdate solution was presented via linear sweep voltammetry,species distribution diagram,Raman spectra,Fourier transform infrared spectrometry and X-ray diffractometry.The results show that there exist two reducible species in ammonium molybdate aqueous solution,i.e.Mo7 O24^6- and molybdenum ammonium complex.In weak acid medium without NH4^+,an obvious reduction peak denoting the reduction of Mo7 O24^6- to molybdenum(Ⅳ)oxides emerges at around-0.7 V(vs SCE).While in neutral and basic solutions without NH4^+,the dominant species changes to MoO4^2-,and accordingly,no reduction peak appears except hydrogen evolution.NH4^+ plays an important role in MoO2 electrodeposition.A new current peak appears at-1.25 V(vs SCE)in both acid and basic solutions,which is attributed to the reduction of molybdenum complex.The effects of solution composition and the electrodeposition conditions on the current efficiency were discussed systematically.By optimizing the electrodeposition conditions,the current efficiency can reach up to51.9%. 展开更多
关键词 MoO2 NH4+ sodium molybdate ELECTRODEPOSITION current efficiency MECHANISM
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Synthesis and Crystal Structure of a Polyoxomolybdate Framework Modified by Mn-L Units(L=3-(2-Pyridyl)pyrazole) 被引量:1
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作者 王庆伟 刘潇潇 +1 位作者 张修堂 李秀梅 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第4期575-579,共5页
A new polyoxomolybdate compound,namely {[MnII(L)(4,4?-Hbipy)(H2O)2]2 [Mo5O15(PO4)2]}.2H2O 1(L = 3-(2-pyridyl)pyrazole,4,4'-Hbipy = protonated 4,4'-bipyridine),was designed and synthesized under hydrothe... A new polyoxomolybdate compound,namely {[MnII(L)(4,4?-Hbipy)(H2O)2]2 [Mo5O15(PO4)2]}.2H2O 1(L = 3-(2-pyridyl)pyrazole,4,4'-Hbipy = protonated 4,4'-bipyridine),was designed and synthesized under hydrothermal conditions.Single-crystal X-ray diffraction analysis result reveals that the [Mo5O15(PO4)2]6-cluster in compound 1 links to two MnII cations via the oxygen of PO43-,which is further coordinated by one 3-(2-pyridyl)pyrazole,one 4,4'-Hbipyridine,and two water molecules. 展开更多
关键词 POLYOXOmolybdate molybdate MANGANESE 3-(2-pyridyl)pyrazole)
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