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91.
本文报道了一种新型三维亚磷酸锌[HO(CH2)2NH3]2•[Zn3(HPO3)4]的合成和晶体结构。在它的结构中,ZnO4和HPO3严格按照顶点连接的方式交替相连。骨架结构存在两个沿着不同方向无限延伸的由ZnO4和HPO3组成的四元环链,在[0 1 0]、[0 4 15]和[0 -4 15]三个方向形成了三个交叉8元环孔道,有机胺阳离子起着平衡电荷和稳定骨架的结构。它的晶体数据为:[HO(CH2)2NH3]2•[Zn3(HPO3)4],M=640.21, 正交晶系, Fdd2空间群, a=2.8528, b=0.8426, c=1.6159nm, Z=8, V=3.884nm3, R1=0.0219, wR2=0.0544。 相似文献
92.
Xiang Ming He Jian Jun Li Yan Cai Yaowu Wang Jierong Ying Changyin Jiang Chunrong Wan 《Journal of Solid State Electrochemistry》2005,9(6):438-444
A novel process is proposed for synthesis of spinel LiMn2O4 with spherical particles from the inexpensive materials MnSO4, NH4HCO3, and NH3H2O. The successful preparation started with carefully controlled crystallization of MnCO3, leading to particles of spherical shape and high tap density. Thermal decomposition of MnCO3 was investigated by both DTA and TG analysis and XRD analysis of products. A precursor of product, spherical Mn2O3, was then obtained by heating MnCO3. A mixture of Mn2O3 and Li2CO3 was then sintered to produce LiMn2O4 with retention of spherical particle shape. It was found that if lithium was in stoichiometric excess of 5% in the calcination of spinel LiMn2O4, the product had the largest initial specific capacity. In this way spherical particles of spinel LiMn2O4 were of excellent fluidity and dispersivity, and had a tap density as high as 1.9 g cm–3 and an initial discharge capacity reaching 125 mAh g–1. When surface-doped with cobalt in a 0.01 Co/Mn mole ratio, although the initial discharge capacity decreased to 118 mAh g–1, the 100th cycle capacity retention reached 92.4% at 25°C. Even at 55°C the initial discharge capacity reached 113 mAh g–1 and the 50th cycle capacity retention was in excess of 83.8%. 相似文献
93.
二甲基甲酰胺中四种钕盐的电导 总被引:3,自引:0,他引:3
通过电导测量研究了四种钕盐:Nd(CF3SO3)3、Nd(ClO4)3、Nd(NO3)3和NdCl3在极性非质子溶剂DMF中的电导性质.利用线性拟合方法求得在25 ℃下Nd(CF3SO3)3和Nd(ClO4)3的极限摩尔电导率分别为278.8和 280.7 S•cm2•mol-1.用间接方法求得Nd(NO3)3 与NdCl3 的极限摩尔电导率分别为297.2和287.3 S•cm2 •mol-1.在25~65 ℃温度范围内,Nd(CF3SO3)3和Nd(ClO4)3的电导率随温度呈线性变化. Nd(NO3)3和NdCl3的电导行为表现出明显的离子缔合. 相似文献
94.
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96.
Jian Wang Xing‐You Xu Lu‐De Lu Xu‐Jie Yang Wei‐Xing Ma Xiang‐Ning Cui 《Surface and interface analysis : SIA》2007,39(6):482-486
The streaming potential of supersaturated solution of binary carboxylic acids, which have even carbon atoms, was determined to characterize crystallization under different temperatures. The value of the streaming potential was related to the type and solubility of the acids and the starting temperature of crystallization, and was easily influenced by the pressure difference of the liquid or the rate of temperature decline. When the temperature was declined to the point where a crystal nucleus appeared, the streaming potential reached the minimum. Thereafter, as the temperature was sequentially lowered, some minicrystals grew, and the streaming potential presented an ascendant tendency. The higher the starting temperature of the acids saturated solution, the higher is the temperature corresponding to the streaming potential minimum. The less the carbon atoms in the acids and the greater the solubility of the acids are, the higher is the temperature of the streaming potential minimum. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
97.
在胶束电动色谱模式下考察了影响生物胺分离的几个因素(如缓冲溶液及SDS浓度、pH、表面活性剂、分离温度及外加电压等)并优化了分离条件,建立了一种简单快速的利用毛细管胶束电动色谱DAD检测器分离分析生物胺的新方法。当缓冲溶液为40mmol/L硼酸缓冲液(pH8.5)、68mmol/LSDS,分离电压为25kV、分离温度为25℃时,5种生物胺在7min内实现了令人满意的基线分离。在优化的条件下,对其线性范围、检出限和重现性进行了测定。结果表明,生物胺的迁移时间的重现性<0.8%,面积的重现性<4%。 相似文献
98.
Established high-throughput proteomics methods provide limited information on the stereostructures of proteins. Traditional technologies for protein structure determination typically require laborious steps and cannot be performed in a high-throughput fashion. Here, we report a new medium throughput method by combining mobility capillary electrophoresis (MCE) and native mass spectrometry (MS) for the 3-dimensional (3D) shape determination of globular proteins in the liquid phase, which provides both the geometric structure and molecular mass information of proteins. A theory was established to correlate the ion hydrodynamic radius and charge state distribution in the native mass spectrum with protein geometrical parameters, through which a low-resolution structure (shape) of the protein could be determined. Our test data of 11 different globular proteins showed that this approach allows us to determine the shapes of individual proteins, protein complexes and proteins in a mixture, and to monitor protein conformational changes. Besides providing complementary protein structure information and having mixture analysis capability, this MCE and native MS based method is fast in speed and low in sample consumption, making it potentially applicable in top–down proteomics and structural biology for intact globular protein or protein complex analysis.Using native mass spectrometry and mobility capillary electrophoresis, the ellipsoid dimensions of globular proteins or protein complexes could be measured efficiently. 相似文献
99.
A three-coil tungsten wire is used as electrode for the preconcentration of cadmium, which is then placed in a graphite tube for atomization and atomic absorption measurement. The heating parameters of the graphite furnace are optimized using the Modified and Weighted Centroid Simplex Method (MWCS), and computer program for automatic calculation. Sulphuric acid is selected as the supporting electrolyte for electrodeposition. The linear range of the calibration graph is 0.00-0.55 ng/ml. The detection limit is 0.01 ng/ml. For 0.1 ng/ml cadmium the coefficient of variation is 3.35% for ten parallel determinations. No interference occurs in the presence of more than 20 coexisting ions. Traces of cadmium in urine of normal people and in river water and the recoveries for cadmium are determined. The results are satisfactory. 相似文献
100.
Qing Qing Meng He Xiang Bai Feng Li Quan Rui Wang Feng Gang Tao 《中国化学快报》2007,18(7):785-787
A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-α]azepine derivatives 7 was developed. The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene a-acetoxy azo compounds 3 with Ar-CN in the presence of AlCl3 and the consecutive ring enlargement. 相似文献