排序方式: 共有69条查询结果,搜索用时 15 毫秒
31.
SnO2纳米晶的水热合成及其气敏特性 总被引:2,自引:0,他引:2
以SnCl2·2H2O和H2O2为主要原料,在无水乙醇和水的混合溶剂中,不同温度下,水热法制备了不同粒径的SnO2纳米晶.利用X射线粉末衍射、透射电子显微镜和比表面积测定等手段对产物进行了表征,并对产物的气敏性进行了测定和分析.结果表明,120、150和180℃时制备的产物均为单相SnO2,其对应的比表面积分别为210.3、125.6和69.2m2/g.产物SnO2对还原性气体CO和C2H5OH均有一定的气敏性,其中对C2H5OH气体的气敏性远大于CO气体.产物气敏性的大小与其比表面积的大小有关,比表面积越大,气敏性越高. 相似文献
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合成和表征了两种新的Schiff碱配合物[ZnL(C104)·4H2O(A)和CdL(C104)·3H20(B)],其中L=2-{2-(Aminomethyl-amino]-methyl}-phenol.A(或B)、FeSO4·7H2O和K3[Fe(ox)3]·3H2O进一步反应,生成了配位聚合物{[ML][Fe^ⅡFe^Ⅲ(ox)3]·H2O}∞,其中M=Zn^2+(C)或Cd^2+(D).红外光谱和Mossbauer谱测定结果表明,C和D具有二维层状结构,其阴离子层由[Fe^ⅡFe^Ⅲ(ox)3]-单元构成. 相似文献
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A novel compound [Cl2Bz(3-MeQl) ](TCNQ) ([Cl2Bz(3-MeQl) ]+ = 1-(3,4-dichlo-robenzyl) 3-methlquinoline cation,TCNQ-= 7,7,8,8-tetracyanoquinodimethanide anion) has been synthesized by the reaction of [Cl2Bz(3-MeQl) ]Br and LiTCNQ,and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic,space group P21/c. The structure analysis shows that the anions are stacked into a column with isolated π-dimers,and there is one type of TCNQ entries(TCNQ) ,in agreement with the IR spectra analysis and density functional theory calculations of the compound. The most prominent structural features are the completely segregated stacking columns of the TCNQ- anions and [Cl2Bz(3-MeQl)]+ cations. 相似文献
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利用水热合成制备了一个新颖的基于柔性多羧酸配体的碱土金属配合物Sr(BuTA)0.5(H2O)2(1)(H4BuTA=1,2,3,4-丁四酸)。利用元素分析及X-射线单晶衍射对其进行了表征。结构分析结果表明标题化合物1属于单斜晶系,P21/c空间群,晶胞参数为a=0.870 03(5) nm,b=0.793 03(5) nm,c=1.268 07(5) nm,β=127.689(3)°,晶胞体积V=0.692 36(7) nm3,Z=4,Dcalc=2.290 g·cm-3,F(000)=468,μ=7.768 cm-1,R=0.015 8,wR=0.037 7。在化合物1中,每个Sr(Ⅱ)的配位环境为八配位的反四棱柱配位构型。在配合物中金属和配体互相连接形成一个三维的框架结构,其拓扑为(46)2(412.612.84)。在其结构中配体是少见的八连接点。对配合物1的热稳定性也做了测试。 相似文献
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合成和表征了两种新的Schiff碱配合物[NiL(ClO4)*3H2O (1)和CuL(ClO4)*4H2O (2),其中L是由摩尔比为1∶1的水杨醛和二乙撑三胺缩合而成的Schiff碱.1(或2)、FeSO4*7H2O和K3[Fe(ox)3]*3H2O进一步反应,生成了双金属层状配位聚合物{[ML][FeⅡFeⅢ(ox)3] *1.5 H2O}∞,其中M2+ = Ni2+ (3)或Cu2+ (4).红外光谱和Mssbauer谱测定结果表明,3和4具有二维层状结构,其阴离子层由[FeⅡFeⅢ(ox)3]-单元构成. 相似文献
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催化动力学分光光度法同时测定铜和铁 总被引:1,自引:0,他引:1
研究发现 :在硫酸介质中Cu(Ⅱ )和Fe(Ⅲ )能同时催化溴酸钾氧化酸性铬蓝K的褪色反应 ,但二者存在一定的速率差异 ,反应速率常数之比随时间而变化 ,且吸光度的加和性不佳。运用了三层Levenberg Marquardt优化BP神经网络处理实验数据 ,实现了Cu(Ⅱ ) ,Fe(Ⅲ )的催化动力学分析法同时测定。研究了最佳反应和测定条件。用于合成样品和人发中铜和铁的测定 ,结果满意 相似文献
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A novel cadmium(Ⅱ) coordination polymer [Cd2(3-pa)4(4,4'-bpy)(H2O)].3.08H2O 1 has been synthesized by pyridine-3-carboxylate (3-pall) and CdO with exo-bidentate rigid dipyridyl ligand 4,4'-bipyridine (4,4'-bpy) by using a hydrothermal method, its structure was determined by single-crystal X-ray diffraction and its luminescent property was also documented. Complex 1 crystallizes in orthorhombic space group Pbcn with a = 21.4074(14), b = 27.1119(18), c = 12.3879(8) A, V = 7189.9(8) A3, Z = 8, C34H32.16Cd2N6O12.08, Mr= 942.85, Dc = 1.742 g/cms, p = 1.255 mm-1 and F(000) = 3766. The structure was solved by direct methods and refined to R = 0.0353 and wR = 0.0891 for 6278 observed reflections (I 〉 2σ(I)). The most prominent structural feature is the mutual interpenetration of two identical 3-D open frameworks via filling the large void space, which gives a 2-fold interpenetrating architecture during the self-assembly process. 相似文献
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建立了HPLC测定市售阿莫西林胶囊中有效成分的方法.采用Agilent C18柱(250mm×4.6mm,5μm),以十八烷基键合硅胶为固定相,0.05mol·L^-1磷酸二氢钾溶液(用2mol·L^-1氢氧化钾溶液调节pH值至5.0)(A)-乙氰(B)(97.5∶2.5,V/V)为流动相.流速为1.0mL·min^-1,柱温为25℃,检测波长为254nm,进样量为10μL.实验结果表明:回归方程为y=5.27x+2.83,r=0.9995(n=6),线性范围20-500μg ·mL^-1,RSD为3.97%,样品中阿莫西林含量为821.3mg/g.此方法具有简单方便、灵敏度高、快速、准确性和重现性好等特点,可用于阿莫西林原料药及其制剂有效成分的质量控制. 相似文献