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101.
本文制备了均匀棒状过氧化氢合碳酸钠,化学分析确定其组成为Na2CO3·1.5H2O2,用DTA-TG-DTG技术并辅以X-ray分析研究了它在静态空气、流动氧气和流动氮气气氛中的非等温热分解过程及动力学。 相似文献
102.
A new polyoxomolybdate complex HNa7[Mo36O112(H2O)16]·47H2O 1 has been prepared in the beaker solution and characterized by single-crystal X-ray diffraction and elemental analyses. Crystal data: H127Mo36Na7O175, Mr = 6542.79, monoclinic, C2/c, a = 40.891(6), b = 17.900(3), c = 25.580(4) , β = 125.673(2)°, V = 15210(4) 3, Z = 4, Dc = 2.857 g/cm3, F(000) = 12464, μ = 3.013 mm-1, R = 0.0633 and wR = 0.1654 (I > 2σ(I)). With the bridging sodium cations, the [Mo36O112(H2O)16]8- units in compound 1 are linked to form a one-dimensional structure, on the basis of which a three-dimensional architecture is further constructed via other sodium cations and complicated hydrogen bonds. 相似文献
103.
104.
在异维生素C钠(D-VcNa)的合成过程中,以SO42-/S iO2-TiO2复合固体超强酸作为酯化反应催化剂,2-酮基-D-葡萄糖酸(2-KGA)和甲醇为原料,采用精馏脱水酯化工艺,不断除去酯化过程中产生的水。催化剂的最佳焙烧温度为550℃,催化剂用量为2.5%;反应时间3~4 h,产品收率为88.6%,催化剂的重复使用性较好,催化体系优于硫酸法。 相似文献
105.
硼氢化钠水解制氢的研究 总被引:8,自引:0,他引:8
采用置换镀的方法在泡沫镍基体上获得不同载钌量的NaBH4水解制氢催化剂。实验结果表明,NaBH4水解制氢反应为零级反应,氢气生成速率随载钌量的增加而变快;当泡沫镍表面完全被钌覆盖时,载钌量为6%,相应的催化能力最强。与离子交换树脂载钌催化剂相比,泡沫镍载钌催化剂更稳定、耐用。实验还证实,30%比35%的NaBH4水溶液在相同的催化剂作用下更易发生水解反应;NaBH4水溶液中加入少量的NaOH有助于提高钌催化剂的催化性能。通过对NaBH4储氢体系的能量计算,说明采用该氢源体系的微型燃料电池的能量密度有望达到甚至超过锂离子电池的比能量水平。 相似文献
106.
H. N. Altshuler L. P. Abramova N. V. Malyshenko G. Yu. Shkurenko E. V. Ostapova 《Russian Chemical Bulletin》2005,54(8):1978-1981
The ion-exchange equilibrium in network polymers obtained from cis-2,8,14,20-tetraphenyl-4,6,10,12,16,18,22,24-octahydroxycalix[4]arene by template synthesis on cations Na+, K+, and Ba2+ as matrices was studied. The selectivity coefficients of ion exchanges Ba2+-H+, Na+-H+, K+-H+, Na+-K+, and Na+-NH4
+ were determined. The template synthesis enhanced the affinity of the polymers to matrix-forming cations by 6–8 kJ mol−1.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1919–1922, August, 2005. 相似文献
107.
MITIC Snezana ZIVANOVIC Valentina OBRADOVIC Mirjana TOSIC Snezana PAVLOVIC Aleksandra 《中国化学》2007,25(4):531-534
The kinetic method for the determination of phosphate microamounts was described. The developed method is based on catalytic effect of phosphate on sodium pyrogallol-5-sulphonate (PS) by dissolved oxygen. The reaction was followed spectrophotometrically by measuring the rate of change in the values of the absorbance of the oxidation product at 437 nm. The optimum reaction conditions are PS (0.44×10^-3 mol·L^-1) and HClO4 (3.6×10^-6 mol·L^-1) at 25 ℃. Following this procedure, phosphate can be determined with a linear calibration graph up to 0.23 μg·mL^-1. The interference effect of several species was also investigated and it was found that the most common cations and anions did not interfere with the determination. The developed procedure was successfully applied to the determination of phosphate in natural waters and soil. 相似文献
108.
A homodinuclear complex (NH3CH2CH2CH2NH3)2 {Na2[(C6H4O2)2] (C6H4O2H)2} (1) has been synthesized by a solution-based self-assembly route. It crystallized in monoclinic system with space group P21/c. Every sodium ion coordinates in a tetragonal prism fashion with two O atoms of a terminal chelating catecholate ligand and three O atoms from two bridging catecholate ligands. Two neighboring NaO5 tetragonal prisms are edge-shared and centrosymmetric with regard to the inversion center to form a binuclear cluster {Na2[(C6H4O2)2](C6H4OOH)2}^4- anion. The complex anions were aligned parallelly by n-n interaction and linked with the protonated 1,3-propylenediamine through hydrogen bonds which were assembled into a multi-lamellar structure with channels. The crystal exhibits rectangular geometry with an interior triangle hollow structure under optical microscopy. And the scanning electron microscopy (SEM) indicates that the wall of the tubes shows multi-lamella morphologies. Further, the transmission electron microscopy (TEM) reveals that the crystal is composed of multi-lamellar nano-tubes with diameters less than 100 nm. The molecular structure of the complex was compared with that of its isomer complex 2. 相似文献
109.
Beitz T Kötz J Wolf G Kleinpeter E Friberg SE 《Journal of colloid and interface science》2001,240(2):581-589
The influence of the nonionic polymer poly(N-vinyl-2-pyrrolidone) (PVP) in comparison to the surfactant 1-octyl-2-pyrrolidinone (OP) on the phase behavior of the system SDS/pentanol/xylene/water was studied. In both modified systems a strong increase in the water solubilization capacity was found, accompanied by a change in the spontaneous curvature toward zero. In the polymer-modified system an isotropic phase channel is formed with increasing polymer content that connects the L1 and the L2 phase. The lamellar liquid crystalline phase is destabilized in both cases. In the L1 phase the adsorption of PVP at the surface of the microemulsion droplets and the formation of a cluster-like structure is proven by several methods like 13C NMR T1 relaxation time measurments, zeta potential measurements, and rheology. In the L2 phase a modification of the interface of the inverse droplets is detected by a shift in the percolation boundary (conductivity) and 13C NMR T1 relaxation measurements. The formation of a cluster-like structure can be assumed on the basis of our rheological measurements. 相似文献
110.
The apparent molar heat capacities of dilute aqueous solutions of acetic, propanoic and succinic acid and sodium salts of the two monofunctional acids were measured at 300 Kp,2
o
. After subtracting the heat capacity of a point mass, the remaining heat capacity was successfully decomposed into functional group contributions at all temperatures. Together with the results of our previous paper on alcohols and diols the heat capacity contributions of the CH2, CH3, OH, COOH, (COOH)2, and COONa groups are now available and these allow reasonably accurate predictions of the heat capacities of all compounds composed of these groups in this temperature range. 相似文献