共查询到20条相似文献,搜索用时 31 毫秒
1.
L. N. Komissarova M. A. Ryumin V. V. Pukhkaya E. V. Samsonova Yu. V. Orlovskii 《Russian Journal of Inorganic Chemistry》2011,56(12):1943-1950
Al synthesized samples are isostructural and crystallize in the orthorhombic symmetry system, space group Ibca. Particles of the final product of ∼200 nm in size have been obtained. The introduction of the vanadate anion into the matrix
composition leads to the lowering of the symmetry of the Eu3+ environment and to the rise of the defect luminescence at 450–550 nm because of the unit cell distortion. The luminescence
of defects in terbium-europium-containing samples is determined by the sample surface area, which decreases on annealing.
The τ, W
0 and γ parameters of the luminescence kinetics of the samples have been determined. 相似文献
2.
S. A. Gromilov Yu. V. Shubin A. I. Gubanov E. A. Maksimovskii S. V. Korenev 《Journal of Structural Chemistry》2009,50(6):1121-1125
Thermolysis of the complex salts (NH4)2[OsCl6]
x
[PtCl6]1−x
(x = 0.25−0.9) formed nanocrystalline Os
x
Pt1−x
phases. Pseudomorphism has been found: the habit of the single crystals of the starting salts is preserved during thermolysis,
and the ∼10–20 nm metal particles are agglomerated into octahedral structures sized 5–10 μm. 相似文献
3.
W. -T. Chen S. -M. Ying Y. -P. Xu Q. -Y. Luo D. -S. Liu 《Journal of Structural Chemistry》2011,52(3):631-634
A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex [Tb0.5(C6NO2H5)3(H2O)2]2n
·(H3O)4n
(ZnCl5)
n
(ZnCl4)2n
(1) is synthesized. It has a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that
it displays interesting emissions in the violet, blue, green, and yellow regions. 相似文献
4.
A multicomponent system of complex refractory oxides of the composition Zn2 − x
(Zr
a
Sn
b
)1 − x
Fe2x
O4 (a + b = 1; a: b = 1: 5, 1: 4, 1: 3, 1: 2, 1: 1, 2: 1, 3: 1, 4: 1; x = 0−1.0; Δx = 0.05) was studied by X-ray diffraction. The samples were prepared from oxides of appropriate metals by low-temperature
plasma synthesis (hydrogen-oxygen flame). Two phases with wide homogeneity ranges were identified: α phase crystallized in
the crystal system of inverse cubic spinel and β phase with the structure of tetragonal spinel. The phase boundaries were
found. Structural data are presented for about 100 solid solutions. 相似文献
5.
A. I. Buvailo L. P. Oleksenko N. P. Maksimovich I. P. Matushko A. P. Ripko V. P. Ruchko 《Theoretical and Experimental Chemistry》2010,46(3):153-157
The effect of cobalt additions on the electrical resistance of adsorption–semiconductor sensors based on nanosized SnO2 in air, their sensitivity to hydrogen, and the catalytic activity of the corresponding sensor materials in the oxidation
of H2 were studied. The extremal nature of the obtained relationships is explained by morphological features of the investigated
systems based on nanosized SnO2. 相似文献
6.
7.
A. I. Pylinina I. I. Mikhalenko 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(12):2109-2114
Characteristics of the catalytic activity in the dehydration of butanols of copper-containing sodium-zirconium-phosphates
(NZPs), in which Na+ ions substitute for Cu2+ ions are obtained. It was found that in the 100–370°C region, the action energy of the reaction falls upon the transition
through temperature T* ∼ 300°C, above which the electrophysical and crystallographic properties of phosphates change. The observed dependences
are explained by the center (which consists of copper with various positions in the phosphate network at T < T* and T > T*) taking part in the formation of carbonyl compounds. This indicates the presence of a ligand effect, i.e., to structural
sensitivity of the dehydration reaction in the case of Cu-NZP catalysts. 相似文献
8.
E. I. Burmakin G. Sh. Shekhtman B. D. Antonov 《Russian Journal of Electrochemistry》2011,47(4):453-456
New potassium-conducting solid electrolytes in the mixed ferrite-aluminate system K0.85Pb0.075(Fe1 − x
Al
x
)O2 are synthesized and studied. The electrolytes exhibit high ionic conductivity in the studied temperature range of 350 to
750°C (approximately 10−2 S/cm at 400°C and approximately 10−1 S/cm at 700°C). An increase in the conductivity with increasing concentration of iron in the specimens is a general tendency.
However, in a wide range of compositions (from x = 0.2 to x = 0.9), the conductivity only slightly depends on x. Possible reasons for the effect of Fe/Al ratio in the structure of solid electrolytes on their transport properties are discussed. 相似文献
9.
V. A. Ketsko E. N. Beresnev M. A. Kop’eva L. V. Elesina A. I. Baranchikov A. I. Stognii A. V. Trukhanov N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2010,55(3):427-429
This work demonstrates the possibility of preparing solid solutions in the (MgGa2O4)
x
(MgFe2O4)1 − x
system by pyrohydrolytic and solid-phase methods. It is shown that the products obtained have different specific surface
areas depending on the ratio between metal nitrates and citric acid. The composition dependence of the unit cell parameter
deviates considerably from the Vegard’s rule. The compounds obtained are found to be stable up to 300°C, which makes them
candidate materials for electronics. 相似文献
10.
采用溶胶-凝胶-程序升温溶剂热一步法,利用表面活性剂EO20PO70EO20(P123)作为模板剂,分别制备了三元纳米复合材料Ag/ZnO-TiO2、Ag/Al2O3-TiO2和Ag/Fe2O3-TiO2。通过XRD、氮气吸附-脱附测定、TEM以及扫描电子显微镜配合X-射线能量色散谱仪(SEM-EDS)等对合成的3种催化剂进行了对比表征分析。结果表明,复合材料Ag/MxOy-TiO2中Ag以单质形式存在并较好地分布在MxOy-TiO2表面上。所合成产物颗粒尺寸较小(约10 nm左右),形貌较好。其中,Ag/ZnO-TiO2的比表面积与Ag/Al2O3-TiO2十分相近,略大于Ag/Fe2O3-TiO2。光催化活性研究中,以甲基橙为模型分子且辅以微波场作用。结果显示,上述三元复合材料的活性均明显高于未掺杂银的二元复合材料,其中Ag/ZnO-TiO2的光催化活性最好,在90 min内对甲基橙的降解率高达86%。 相似文献
11.
V. V. Kaichev Yu. V. Dubinin T. P. Smirnova M. S. Lebedev 《Journal of Structural Chemistry》2011,52(3):480-487
By X-ray photoelectron spectroscopy (XPS), using the technique of layer-by-layer analysis, the films of (HfO2)
x
(Al2O3)1−x
solid solutions synthesized by chemical vapor deposition are studied. The possibility to determine the structure of solid
binary solutions based on the analysis of the XPS spectra is demonstrated. 相似文献
12.
I. V. Spesivtseva N. A. Kochetova E. M. Gorbunova I. E. Animitsa 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(10):1689-1694
Solid solutions of the composition Ba2(In1 − x
Al
x
)2O5[VO]1 (0 ≤ x ≤ 0.20) with an incomplete oxygen sublattice were obtained. It was established that, along with an increase in parameter
x, there is disordering of oxygen vacant positions and a transition from the structure of brownmillerite to that of defect
perovskite. It was demonstrated that the phases under study are characterized by an ability for reversible interaction with
water vapors in the temperature range 150–450°C. During this process, proton defects, predominantly in the form of OH− groups, are formed in the oxide structure. We conclude that in a number of solid solutions, the amount of intercalated water
declines upon an increase in the aluminum content. 相似文献
13.
E. A. Filonova A. N. Petrov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(11):1832-1835
The homogeneity regions of Nd1 − x
Ba
x
MnO3 (0.0 ≤ x ≤ 0.25) and NdMn1 − y
Fe
y
O3 (0.0 ≤ y ≤ 1.0) orthorhombic solid solutions in air at 1373 K were determined. The region of the existence of Nd1 − x
Ba
x
Mn1 − y
Fe
y
O3 orthorhombic solid solutions in air at 1373 K was studied. A fragment of the phase diagram of the NdMnO3-BaMnO3-BaFeO2.5-NdFeO3 quasi-quaternary complex oxide system in air at 1373 K was suggested. The mechanothermal properties of Nd0.75Ba0.25MnO3, Nd0.8Ba0.2Mn0.9Fe0.1O3, Nd0.8Ba0.2Mn0.7Fe0.3O3, and Nd0.8Ba0.2Mn0.5Fe0.5O3 doped neodymium manganates were studied. 相似文献
14.
A. S. Monaenkova A. A. Popova L. A. Tiflova M. L. Kovba 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(7):1085-1088
The enthalpies of reactions of Sm1 + x
Ba2 − x
Cu3O
y
substitution solid solutions (x = 0, 0.1, 0.2, 0.3, 0.7, and 0.8) with 1.07 N HCl were measured at 298.15 K in a hermetic isothermic-shell swinging calorimeter.
The results and the literature data were used to calculate the standard enthalpies of their formation from simple substances
and binary oxides (Δf
H
298.15o and Δox
H
298.15o). The dependence of the enthalpy of formation on the degree of samarium substitution for barium was obtained. 相似文献
15.
A. S. Monaenkova A. A. Popova L. A. Tiflova E. A. Gudilin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(8):1280-1284
The enthalpies of reactions of substitution solid solutions Pr1 + x
Ba2 − xCu3O
y
, where x = 0, 0.2, 0.4, 0.6, and 0.9, with 1.07 N HCl were measured at 298.15 K in a hermetic swinging isothermic-shell calorimeter.
The results and the literature data were used to calculate the standard enthalpies of formation of solid solutions from the
elements and oxides. The dependence of the enthalpy of solid solution formation on the degree of praseodymium substitution
for barium (x) was revealed. 相似文献
16.
A series of Cs2Te0.2H0.6 + x PMo12 − x V x O n (x = 0–3) heteropoly compounds has been prepared and tested in the partial oxidation of isobutane. Catalytic tests show that at 350°C very high selectivity to methacrylic acid (60.1%) can be achieved at isobutane conversion of 12.2% over a Cs2.0Te0.2H1.6PMo11VO n catalyst with only one molybdenum atom per unit cell substituted by vanadium. The presence of Te4+ in the heteropoly compounds appears to interfere with the dehydrqgenation step and favor the formation of methacrolein and methacrylic acid. 相似文献
17.
The quantum-chemical calculations of the (C6H5)2PCl3 molecule were performed by the methods RHF/6-31G(d) and MP2/6-31G(d) with complete and partial optimization of its geometry.
The results of calculations were used for evaluating the NQR frequencies of 35Cl and the parameters of asymmetry of the of electric field gradient on the 35Cl nuclei of this molecule. According to the results of calculations with the partial optimization of geometry and to the
experimental data of 35Cl NQR the bond lengths were found of central atom P in the solid state of this compound. The mutual influence of its axial
and equatorial bonds was studied. It is shown that in chlorophosphoranes the 35Cl NQR frequencies of the axial and equatorial chlorine atoms decrease with the decrease in the bond lengths of phosphorus
atom. 相似文献
18.
M. A. Ryumin V. V. Pukhkaya L. N. Komissarova 《Russian Journal of Inorganic Chemistry》2011,56(9):1343-1350
Samples with various dopant contents were obtained using solid-state and sol-gel methods. The resulting single-phase samples
have the formula K2Y1 − x
Eu
x
(MoO4)(PO4)0.9(VO4)0.1 (x = 0, 0.005, 0.01, 0.02, 0.03) and are isostructural with K2Y(MoO4)(PO4). The possibility of formation of complex molybdate vanadates M2IMIII(MoO4)(VO4). was studied. Unlike their precursor K2Y(MoO4)(PO4), the complex potassium yttrium molybdate phosphates obtained are deliquescent. Their structures contain no water molecules.
The absorption and emission spectra of the compounds under study were recorded. In all the spectra, the electric dipole transition
5
D
0−7
F
2 (616 nm) is appreciably more intense than the magnetic dipole transition 5
D
0−7
F
1 (590 nm). This suggests that the coordination environment of the Eu3+ ion keeps asymmetric. The excitedstate lifetimes of anhydrous and humidified samples were determined. The average lifetime
is the same for all samples (≈1.5 ms), which is due to the stability of their structures. 相似文献
19.
A. R. Shaikhlislamova I. A. Stenina A. B. Yaroslavtsev 《Russian Journal of Inorganic Chemistry》2008,53(12):1829-1833
Synthesis and ionic conductivity of Li3−2x
Nb
x
Fe2−x
(PO4)3 complex phosphates were studied by X-ray powder diffraction and impedance spectroscopy. These phosphates are formed only
at 900–1000°C. Variations in their thermal expansivity and unit cell parameters induced by aliovalent doping were characterized.
The conductivity of these materials increases monotonically in the series Li0.5Nb1.25Fe0.75(PO4)3-LiNbFe(PO4)3 and Li1.2Nb0.9Fe1.1(PO4)3-Li3Fe2(PO4)3, which is explained by consecutive occupation of the Li(1) and Li(2) positions in their structures.
Original Russian Text ? A.R. Shaikhlislamova, I.A. Stenina, A.B. Yaroslavtsev, 2008, published in Zhurnal Neorganicheskoi
Khimii, 2008, Vol. 53, No. 12, pp. 1957–1962. 相似文献
20.
将不同比例的铈锆前驱体负载到ZIF-67,氮气气氛焙烧制备CexZr1-xO2/Co/C-N催化剂,对催化剂进行了XRD,H2-TPR、XPS表征,并在固定床反应器评价其CO2加氢制甲醇性能。XRD结果表明,在铈中加入适量锆形成铈锆固溶体,铈锆固溶体与钴物种较强的相互作用力可以阻止表明金属Co的氧化。但过量加入的锆又会削弱这一作用力,部分金属Co被氧化为Co3O4。H2-TPR结果表明适量的锆的加入改善催化剂的还原性能,催化剂还原温度降低。XPS证实了25%Ce0.67Zr0.33O2/Co/C-N催化剂中含有更多的氧空穴及氮含量,氧空穴和碱性氮都有利于CO2的解离吸附。优化后的25%Ce0.67Zr0.33O2/Co/C-N 催化剂在225 oC,2 MPa,GHSV = 6 L/gcat/h反应条件下取得最高甲醇时空收率,为3.0 mmol/gcat/h。 相似文献