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丙醇—溴化十六烷基三甲胺—硫酸铵—水体系萃取分离汞(Ⅱ) 总被引:1,自引:0,他引:1
研究了丙醇-溴化十六烷基三甲胺9CTMAB)-(NH4)2SO4-水体系萃取分离泵的行为及与常见离子分离条件。试验表明:调节pH1.0或3.0,能使Hg从Fe^3+,Co^2+,Ni^2+m,Zn^2+,Mn^2+,Cu^2+,Al63+等离子混合液中分离出来。 相似文献
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合成了(CeO2)0.7-x(MO)x(La2O3)0.3(M-Mg、Ca、Sr)固体电解质。对其晶体结构、电导率、XPS谱、离子迁移数及制成的燃料电池的V-I曲线进行了测定。(CeO2)0.7(La2O3)0.3中掺入Ca^2+、Mg^2+或Sr^2+,可使电解质的氧离子导电性能改善,从而使制成的燃料电池的开路电压输出功率也得到提高。 相似文献
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PTFE—乙醚柱反相萃取层析连续分离和测定镓(Ⅲ)铟(Ⅲ)的研究 总被引:2,自引:3,他引:2
研究了在抗坏血酸存在下的6mol/L HBr介质作流动相,以PTFE(聚四氟乙烯)负载的乙醚作固定相,反相萃取层析使微量Ga(Ⅲ),In(Ⅲ)与Fe^3+、Tl^3+、Mo^6+、Au^3+、Ti^4+、Bi^3+、Al^3+、Mg^2+、Ca^2+、Ni^2+、Co^2+、Cd^2+、Zn^2+、Pb^2+、Cu^2+等多种离子分离。留于柱上的铟、镓分别用HCl(4mol/L)-H2O2(3%) 相似文献
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采用单柱离子色谱系统和电导检测的方法,以丙二酸为淋洗液,同时有效地分离、检测了溶液中SO4^2-、Cl^-、NO3^-、F^-、NH4^+、K^+、Mg^2+、Ca^2+9种离子。研究了丙二酸浓度和流速对各离子保留时间及电导检测行为的影响。该法用于目前市售饮用水中的阴阳离子分析,得到了满意的结果。 相似文献
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本文研究了与Keggin结构相关的31种3大系列(2:18系列,1:11系列和双系列)杂多化合物的红外光谱,它们是:NP2W18(N=(CH3)4N^+,(C2H5)4N^+,(C4H9)4N^+),MP2W18(M=Li^+,Na^+,Ag^+,Cu^2+);KnZW11(Z=P,B,Ge,Si),MSiW11(M=Mn,Zn,Cu,Co,Ni)和M(PW11)2(M=Ce,Pr,Nd,Sm,E 相似文献
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研究了4种C7H7Cl异构体在70eV电子轰击下产生的[C7H7Cl]^2+、[C7H6Cl]^2+.和[C7H5Cl]^2+ 3种双电荷离子的电子捕获诱导解离(ECID)反应。分子离子的ECID反应明显的邻位效应,表明其结构仍保持中性分子的结构特征;而由各异构体产生的[C7H6Cl]^2+.和[C7H5Cl]^2+离子异构化成同一结构。3种双电荷离子ECID反应的产物与离子所带电子的奇偶性有关, 相似文献
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Antonija Dindune Zaiga Kanepe Edvardas Kazakeviius Algimantas Keionis Janis Ronis Antanas Orliukas 《Journal of Solid State Electrochemistry》2003,7(2):113-117
Compounds of the system Li1+
x
M
x
Ti2–
x
(PO4)3 (where M=Sc, Al, Fe, Y; x=0.3) were synthesized by a solid-state reaction and studied by X-ray diffraction. The ceramic samples were sintered and investigated
by complex impedance spectroscopy in the frequency range 106–1.2×109 Hz in the temperature range 300–600 K. Two relaxation dispersions related to the fast Li+ ion transport in bulk and grain boundaries were found. The activation energies of the bulk conductivity and relaxation frequency
were obtained from the slops of Arrhenius plots. The values of the activation energies of the bulk ionic conductivity and
relaxation frequency were found to be very similar in all the materials investigated. That can be attributed to the fact that
the temperature dependences of the bulk conductivity are caused only by the mobility of the fast Li+ ions, while the number of charge carriers remains constant with temperature.
Electronic Publication 相似文献
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M.E. Villafuerte-Castrejón J.A. Azamar-Barrios P. Bartolo-Pérez 《Journal of solid state chemistry》1998,140(2):755
Two unusual, extensive new solid solutions of LiNbO3and LiTaO3with MnO have been prepared, where 4Mn2+replace a combination of 3Li+and a pentavalent cation: Nb5+or Ta5+. The formulas are Li1−xM1−xMn4xO3, 0<x<0.13, forM=Nb and 0<x<0.23 forM=Ta. The solid solutions were characterized by X-ray powder diffraction and density measurements. The manganese oxidation states were determined by X-ray photoelectron spectroscopy. 相似文献
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Lisa J. Gillie Sharon A. de Souza Nik Reeves-McLaren Anthony R. West 《Journal of solid state chemistry》2010,183(11):2589-2597
A new vanado-molybdate LiMg3VMo2O12 has been synthesized, the crystal structure determined an ionic conductivity measured. The solid solution Li2−zMg2+zVzMo3−zO12 was investigated and the structures of the z=0.5 and 1.0 compositions were refined by Rietveld analysis of powder X-ray (XRD) and powder neutron diffraction (ND) data. The structures were refined in the orthorhombic space group Pnma with a∼5.10, b∼10.4 and c∼17.6 Å, and are isostructural with the previously reported double molybdates Li2M2(MoO4)3 (M=M2+, z=0). The structures comprise of two unique (Li/Mg)O6 octahedra, (Li/Mg)O6 trigonal prisms and two unique (Mo/V)O4 tetrahedra. A well-defined 1:3 ratio of Li+:Mg2+ is observed in octahedral chains for LiMg3VMo2O12. Li+ preferentially occupies trigonal prisms and Mg2+ favours octahedral sheets. Excess V5+ adjacent to the octahedral sheets may indicate short-range order. Ionic conductivity measured by impedance spectroscopy (IS) and differential scanning calorimetry (DSC) measurements show the presence of a phase transition, at 500-600 °C, depending on x. A decrease in activation energy for Li+ ion conductivity occurs at the phase transition and the high temperature structure is a good Li+ ion conductor, with σ=1×10−3-4×10−2 S cm−1 and Ea=0.6 to 0.8 eV. 相似文献
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采用微波固相法制备了CaWO4:xEu3+,ySm3+,zLi+红色荧光粉。测量样品的XRD图、激发谱、发射谱及发光衰减曲线,研究并分析了Eu3+、Sm3+、Li+的掺杂浓度,对样品微结构、光致发光特性、能量传递及能级寿命的影响。结果表明,Eu3+、Sm3+、Li+掺杂并未引起合成粉体改变晶相,仍为CaWO4单一四方晶系结构。Eu3+、Sm3+共掺样品中,Sm3+掺杂为3%时,Sm3+对Eu3+的能量传递最有效。Li+掺杂起到了助熔剂和敏化剂的作用,使样品发光更强。在394 nm激发下,与CaWO4:3%Eu3+样品比较,3%Eu3+、3%Sm3+共掺CaWO4及3%Eu3+、3%Sm3+、1%Li+共掺CaWO4样品的发光分别增强2倍及2.4倍。同一激发波长下,单掺Eu3+样品寿命最短,Sm3+、Eu3+共掺样品随Sm3+浓度增加,寿命先减小后增加,且掺杂了Li+的样品比不掺Li+的样品5D0能级寿命有所增加。 相似文献
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Crystal Structure and Electric Conductivity of Spinel-Type Li2–2xMn1+xCl4 Solid Solutions The electric conductivity of the fast lithium ion conductors Li2–2xMn1+xCl4 was measured by impedance spectroscopic methods. The conductivities obtained, e.g. ~ 4 × 10?1 Ω?2 cm?1 at 570 K, depend only little on the lithium content. The crystal structure of Li1.6Mn1.2Cl4 was determined by neutron powder and X-ray single crystal diffraction (space group Fd3 m, Z = 8, a = 1 049.39(6) pm, Rw = 1.4% on the basis of 170 reflections). The lithium deficient chloride crystallizes in an inverse spinel structure like the stoichiometric compound Li2MnCl4 according to the formula (Li0,8)[Li0,4Mn0,6]2Cl4 with vacancies ( ) at the tetrahedral sites. The decrease of the Moct? Cl distances with the increase of x reveals that the ionic radius of Mn2+ in chlorides is equal or even smaller than that of Li+ opposite to fluorides and oxides. The ? Cl distances of spinel type chlorides are 237 ( tet) and 274 pm ( oct), respectively. The mechanism of the ionic conductivity is discussed. 相似文献
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6Li and 7Li MAS NMR spectra including 1D-EXSY (exchange spectroscopy) and inversion recovery experiments of fast ionic conducting Li2MgCl4, Li2-xCuxMgCl4, Li2-xNaxMgCl4, and Li2ZnCl4 have been recorded and discussed with respect to the dynamics and local structure of the lithium ions. The chemical shifts, intensities, and half-widths of the Li MAS NMR signals of the inverse spinel-type solid solutions Li2-xMIxMgCl4 (MI=Cu, Na) with the copper ions solely at tetrahedral sites and sodium ions at octahedral sites and the normal spinel-type zinc compound, respectively, confirm the assignment of the low-field signal to Litet of inverse spinel-type Li2MgCl4 and the high-field signal to Lioct as proposed by Nagel et al. (2000). In contrast to spinel-type Li2-2xMg1+xCl4 solid solutions with clustering of the vacancies and Mg2+ ions, the Cu+ and Na+ ions are randomly distributed on the tetrahedral and octahedral sites, respectively. The activation energies due to the various dynamic processes of the lithium ions in inverse spinel-type chlorides obtained by the NMR experiments are Ea=6.6-6.9 and ΔG*>79 KJ mol−1 (in addition to 23, 29, and 75 kJmol-1 obtained by other techniques), respectively. The largest activation energy of >79 KJ mol−1 corresponds to hopping exchange processes of Li ions between the tetrahedral 8a sites and the octahedral 16d sites. The smallest value of 6.6-6.9 KJ mol−1, which was derived from the temperature dependence of both the spin-lattice relaxation times T1 and the correlation times τC of Litet, reveals a dynamic process for the Litet ions inside the tetrahedral voids of the structure, probably between fourfold 32e split sites around the tetrahedral 8a site. 相似文献
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Christopher M. Johnson Mark G. Shilton Arthur T. Howe 《Journal of solid state chemistry》1981,37(1):37-43
We have measured the ionic conductivities of pressed pellets of the layered compounds MUO2PO4 · nH2O, and correlated the results with TGA data. The conductivities (in ohm?1 m?1), at temperatures increasing with decreasing water content over the range 20 to 200°C, were approximately as follows: Li+4H2O, 10?4; Li+, Na+, K+, and NH4+3H2O, 10?4, 10?2, 10?4, and 10?4; H+, Li+, and Na+1.5H2O, 10?2, 10?4, and 10?4; Na+1H2O, 10?5; H+, K+, and NH4+0.5H2O, all 10?5; and H+, Li+, Na+, K+, NH+4, and , 10?5, 10?5, 10?4, 10?5, 10?5, and 10?6. A ring mechanism is proposed to account for the high conductivity found in NaUO2PO4 · 3.1H2O. The accurate TGA data showed that most of the hydrates had water vacancies of the Schottky type, and should be represented as MUO2PO4(A ? x)H2O, where x can be between 0 and 0.3. 相似文献
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Binary ionogenic equilibria (RX + MtXx ? R+MtXn + l? ? R+ + MtXn + 1?, R = φ3C, (pClC6H4)3C; X = Cl; Mt = Hg) are studied in CH2Cl2 by conductivity and u.v. spectroscopy. The importance of such studies to cationic polymerisation is emphasised. The equilibrium constants, the thermodynamic parameters and the molar conductivities of the individual ions are given and the results discussed both in terms of a comparison between the two systems studied and in terms of a comparison with similar data in the literature. 相似文献
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Garnet-structure related metal oxides with the nominal chemical composition of Li5La3Nb2O12, In-substituted Li5.5La3Nb1.75In0.25O12 and K-substituted Li5.5La2.75K0.25Nb2O12 were prepared by solid-state reactions at 900, 950, and 1000 °C using appropriate amounts of corresponding metal oxides, nitrates and carbonates. The powder XRD data reveal that the In- and K-doped compounds are isostructural with the parent compound Li5La3Nb2O12. The variation in the cubic lattice parameter was found to change with the size of the dopant ions, for example, substitution of larger In3+(rCN6: 0.79 Å) for smaller Nb5+ (rCN6: 0.64 Å) shows an increase in the lattice parameter from 12.8005(9) to 12.826(1) Å at 1000 °C. Samples prepared at higher temperatures (950, 1000 °C) show mainly bulk lithium ion conductivity in contrast to those synthesized at lower temperatures (900 °C). The activation energies for the ionic conductivities are comparable for all samples. Partial substitution of K+ for La3+ and In3+ for Nb5+ in Li5La3Nb2O12 exhibits slightly higher ionic conductivity than that of the parent compound over the investigated temperature regime 25-300 °C. Among the compounds investigated, the In-substituted Li5.5La3Nb1.75In0.25O12 exhibits the highest bulk lithium ion conductivity of 1.8×10−4 S/cm at 50 °C with an activation energy of 0.51 eV. The diffusivity (“component diffusion coefficient”) obtained from the AC conductivity and powder XRD data falls in the range 10−10-10−7 cm2/s over the temperature regime 50-200 °C, which is extraordinarily high and comparable with liquids. Substitution of Al, Co, and Ni for Nb in Li5La3Nb2O12 was found to be unsuccessful under the investigated conditions. 相似文献
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N.K. Appandairajan B. Viswanathan J. Gopalakrishnan 《Journal of solid state chemistry》1981,40(1):117-121
Substitution of Li+ into Co3O4 and ZnCo2O4 gives rise to the solid solution series LixM1?xCo2O4 (M = Co2+ or Zn2+) having the spinel structure upto x = 0.4. X-Ray diffraction intensities show that the spinel solid solutions are likely to have the following cation distributions: (Co2+)t[Li+xCo3+2?3xCo4+2x]0O4 and (Zn2+1?xCo2+x)t[Li+xCo3+2?3xCo4+2x]0O4. Electrical resistivity and Seebeck coefficient data indicate that the electron transport in these systems occurs by a small-polaron hopping mechanism. 相似文献