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以LiTi2(PO4)3为基以天然高岭石为起始原料,经高温固相反应(950~1150℃)制得了 一系列锂快离子导体材料Li1+2x+yAlxYbyTi2-x-ySixP3-xO12(以下简称Al-Yb-Lisicon).系统 的合成温度随x和y值的增大而降低.应用交流阻抗技术测定的电导率数据结果表明y=0.3, x=0.1的合成物的电导率最好,400℃时电导率达2.45×10-2S/cm, 200~400℃内的电导激 活能为38.3kJ/mol.XRD分析结果表明在y=0.3,x≤04及y=0.5,x≤0.3的组成范围内 均能得到空间群为R3c的合成物. 相似文献
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立方A^4+M^5+2O7型化合物与新型负热膨胀材料 总被引:1,自引:0,他引:1
概述了立方A^4+M^5+2O7型化合物的结构特点,讨论了AV2-xPxO7型(A=Zr或Hf;x=0.1~1.2)及其部分取代的A^4+1-yB^4+yV2-xPxO7型(B=Ti,Ce,Th,U,Mo,Pt,Pb,Sn,Ge或Si;y=0.1~0.4)和A^4+1-yC^1+yD^3+yV2-xPxO7型(C为碱金属元素,D为稀土金属元素)材料的负热膨胀性能。 相似文献
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用溶胶-凝胶法合成了Li2+xBxSi1-xO3(x=0-0.5),发现形成固溶体的范围是0〈x≤0.2。对其离子导电性的研究发现,当x=0.3时出现电导率极大值。 相似文献
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以高岭石和NaTi2(PO4)3为基的钠快离子导体 总被引:3,自引:1,他引:2
本文以高岭石为起始原料、以NaTi2(PO4)3为母体结构,通过高温固相反应合成快离子导体Na1+2xAlxTi2-xSixP3-xO12系统,并研究了此系统的相组成、结构和电性能.大多数合成反应在1073~1223K下完成.在。x<0.6的组成范围内可形成具有NASICON结构、空间群为C2/c的固溶体·x射线粉末衍射分析表明随。的增大,系统各合成物的晶胞参数增大.x=0.4的合成物具有最好的离子电导率,673K时达3.00×10-3S/cm,而激活能为36.02kJ/mol. 相似文献
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Nasicon型快离子导体Na1+xZr2-yM0.8ySixP3-xO12系统采用高温固相合成,春合成温度在1373K左右完成,该的合成温度在x不变的情况下,随着y的增大而降低,大多烽合成物为单斜晶系;空间群为C3/c。当y不变,x增大地基地率的变化是先增大,后减小。最佳导一的起始组成为x=1.5、y=0.1,其电导率在室温时为3.20×10^-4S/cm,在673K时为6.88×10^-2S/ 相似文献
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采用高温固相反应法制备了一系列白光LED用CaSi2O2N2:0.05Eu2+,xDy3+,xLi+(0≤x≤0.03)荧光粉.利用X射线衍射仪对样品的物相结构进行了分析,结果表明:Dy3+和Li+离子的掺入没有改变CaSi2O2N2:Eu2+荧光粉的主晶相.利用荧光光谱仪对样品的发光性能进行了测试,发现所有样品的激发光谱均覆盖了从近紫外到蓝光的较宽范围,400 nm激发下得到的发射光谱为宽波段的单峰,峰值位于545 nm左右,是Eu2+离子5d-4f电子跃迁引起的.Dy3+离子掺杂可以提高CaSi2O2N2:Eu2+荧光粉的发光强度,Dy3+与Li+共掺杂可进一步提高荧光粉的发光强度,当Dy3+和Li+的掺杂量为1mol%时,荧光粉的发光强度达到最大值,是单掺杂Eu2+的荧光粉发光强度的157%. 相似文献
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Ti/SnO2+Sb2O3+MnO2/PbO2阳极的性能研究 总被引:10,自引:0,他引:10
制备了一种非贵金属阳极-Ti/SnO2 Sb2O3 MnO2/PbO2,并用XRD、SEM进行了表征,计算出了电极的分形维数,测定了该电极在硫酸中的使用寿命和动力学参数,把该电极用于处理含酚废水和Pb电极进行对,结果表明,节电33%,转化率达95%,是一种优良的电化学催化剂。 相似文献
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Shigeki Iyoki Masahito Nakanishi Hiroshi Yoshida Tohru Okuda Tadashi Uemura 《International Journal of Refrigeration》1993,16(4)
The thermodynamic properties (solubility, vapour pressure, density, viscosity, heat capacity and heat of mixing) of the H2O + CH3OH + LiBr + ZnCl2 (9:1 H2O:CH3OH and 1:1 LiBr:ZnCl2 by mass) system using H2O + CH3OH as the working media and LiBr + ZnCl2 as the absorbents were measured. The solubility data were obtained in the temperature range from 270.35 to 389.55 K. The measurements of vapour pressure, density, viscosity and heat capacity were carried out at various temperatures and absorbent concentrations. The differential heat of dilution and differential heat of solution at 298.15 K were measured for solutionw with absorbent concentrations from 0 to 75.2 wt%. The integral heat of mixing data at 298.15 K were obtained from both sets of experimental data. The integral heats of mixing for this quaternary system showed exothermic behaviour. The vapour pressure data were correlated with an Antoine-type equation. An empirical formula for the heat capacity was obtained from experimental data. The experimental data for the basic thermodynamic properties of this quaternary system were compared with those of the basic H2O + LiBr system. 相似文献
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以原位插层共聚法制备木质纤维素-g-丙烯酸/丙烯酰胺/蒙脱土(LNC-g-AA/AM/MMT)纳米复合材料,采用X射线衍射(XRD)、扫描电镜(SEM)对其结构进行表征。研究在金属离子初始浓度、吸附时间、吸附温度、pH值等不同吸附条件下,LNC-g-AA/AM/MMT纳米复合材料对Pb2+、Cd2+吸附性能的影响。结果表明,当Pb2+、Cd2+初始浓度分别为0.04和0.06mol/L,吸附时间分别为120和60min,吸附温度分别为40和30℃,pH值为5.5时,LNC-g-AA/AM/MMT纳米复合材料对Pb2+、Cd2+的吸附量分别高达504.2和246.9 mg/g。整个吸附过程均符合Langmuir吸附等温线模型和伪二级动力学模型,且是个自发放热的反应过程。同时对最佳条件下吸附饱和的LNC-g-AA/AM/MMT纳米复合材料进行解吸研究,脱附率分别为93.4%和92.9%。 相似文献
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载银纳米二氧化钛的表面改性 总被引:3,自引:0,他引:3
采用硅烷偶联剂对载银纳米二氧化钛(TiO2/Ag )进行表面改性,考察了偶联剂用量、反应时间、反应温度及pH值对表面改性的影响,从而确定最佳用量和最佳反应条件.利用元素分析、红外光谱(FTIR)和透射电子显微镜(TEM)等表征手段及亲油化度的测定,研究了表面改性的效果及分散状况.结果表明:TiO2/Ag 纳米粉体表面处理的最佳条件为:硅烷偶联剂KH560添加量8%,反应的水浴温度78.5℃,反应时间4小时,pH=7;KH560以化学键的形式接枝在粉体表面,同时,经过表面改性后的载银纳米TiO2的亲油性和分散性与未改性的粉体相比明显得到改善. 相似文献
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R. Jabłoński 《Materials Research Bulletin》1973,8(8):909-914
Superhyperfine structure s.h.f.s. resulting from the Cr2+ - F? interaction was studied in Cr2+ doped CdF2 crystals. The s.h.f.s. observed can be described with by the following spin-Hamiltonian The constants calculated are . The measurements were made with an ESR spectrometer at X band at 4.2 OK. 相似文献
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Photodegradation of direct yellow-12 using UV/H2O2/Fe2+ 总被引:6,自引:0,他引:6
A detailed investigation of photodegradation of direct yellow-12 (DY12) using UV/H(2)O(2)/Fe(2+) has been carried out in a photochemical reactor. Experiments studied degradation as a function of concentration, decolorization and reduction in chemical oxygen demand (COD). The effect of operating parameters, such as UV, pH, amount of Fenton's reagent (H(2)O(2) and FeSO(4)), and amount of DY12 dye has also been determined. It has been observed that simultaneous utilization of UV irradiation with Fenton's reagent increases the degradation rate of DY12 dye. The dye quickly losses its color and there is an appreciable decrease in COD value, indicating that the dissolved organic have been oxidized. The kinetics of degradation of the dye in dilute aqueous solutions follows pseudo-first order kinetics. Final products detected at the end of the reaction include NO(3)(-), NO(2)(-), N(2)O, NO(2), SO(2), CO(2) and CO. Results indicate that dye degradation is dependent upon pH, UV-intensity, concentration of Fenton's reagent and dye. Acidic pH has been found to be more suitable in comparison to neutral and alkaline. The optimum concentration of Fenton's reagent (H(2)O(2)/Fe(2+)) was found as 1500/500 mg l(-1) for 50 mg l(-1) DY12 dye in water at pH 4. The results indicate that the treatment of DY12 dye wastewater with UV/Fe(2+)/H(2)O(2) system is efficient. 相似文献
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载铜锌纳米羟基磷灰石的抗菌性能及机理研究 总被引:17,自引:0,他引:17
在常压下合成了纳米羟基磷灰石(n—HA)浆料,并在水介质中制备了载铜、载锌和载铜锌双离子n—HA抗菌材料.运用原子吸收光谱(AAS)、转靶X射线衍射(XRD)、透射电镜(TEM)等手段对材料的理化性能进行了表征.并对该抗菌材料的抗菌性能进行了研究.结果表明,载铜和载铜锌双离子n—HA抗菌材料对革兰氏阴性菌E.coil和革兰氏阳性菌S.aureus均有较强的抑制和杀灭作用,而载锌n—HA的抗菌能力较弱.本文还通过实验探讨了该抗菌材料的抗菌机理. 相似文献