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61.
3-Acetonyl-1,2,4-oxadiazoles and 2-acetonyl-1,3,4-oxadiazoles are accessible starting with the ketal of acetoacetamide oxime and the ketal of acetoacetic acid hydrazide, respectively. 5-Acetonyl-1,2,4-thiadiazoles are obtained from 5-chloro-1,2,4-thiadiazoles andtert.-butyl acetoacetate. These Acetonyl-azoles are starting materials for three series of azolylvinyl phosphates and phosphonates.
Herrn Prof. Dr.Klaus Weissermel zu seinem 60. Geburtstag.  相似文献   
62.
铁电极上硫脲及衍生物的缓蚀作用研究   总被引:7,自引:1,他引:7  
用极化曲线方法测定了硫酸溶液中硫脲及其衍生物的浓度变化对铁腐蚀电化学行为的影响,获得了腐蚀电位下缓蚀剂对阴极和阳极过程的作用系数,用EHMO方法对硫脲及其衍生物的结构参数进行了量化计算,分析表明,缓蚀剂对阴极和阳极过程作用系数的大小与这些参量有密切关系。  相似文献   
63.
64.
Excess molar enthalpies of binary mixtures for tributyl phosphate (TBP)+methanol/ethanol were measured with a TAM air Isothermal calorimeter at 298.15 K and ambient. The results for xTBP+(1–x)CH3OH are negative in the whole range of composition, while the values for xTBP+(1–x)C2H5OH change from positive values at low x to small negative values at high x. The experimental results have been correlated with the Redlich–Kister polynomial. IR spectra of the mixtures were measured to investigate the effect of hydrogen bonding in the mixture.  相似文献   
65.
El-shahat MF  Moawed EA  Zaid MA 《Talanta》2003,59(5):851-866
The present work describes a novel method for the incorporation of Nile blue A into polyurethane foam matrix. This foam material was found to be very suitable for the extraction of metal ions from aqueous solutions. The characterization of Nile blue A grafted foam and the effect of halide concentration, pH, shaking time, extraction isotherm and capacity have been investigated. This foam material was found to be suitable for the separation and preconcentration of iron (III), zinc (II), cadmium (II) and mercury (II) from waste water. The extraction was accomplished in (15-20) minutes. Iron was separated from acid medium (2-4 M HCl), zinc from (3-5 M HCl), cadmium from (4-6 M HCl) as thiocyanate complexes and mercury was separated from (1-2 M HCl) as chloride.  相似文献   
66.
一种新的磷酸根离子敏感电极研究   总被引:5,自引:0,他引:5  
一种新的磷酸根离子敏感电极研究肖丹,俞汝勤,李军,袁孔铨(湖南大学化学化工系,长沙,410082)关键词磷酸根,离子选择电极,磷酸二氢根磷酸根离子浓度的测定在化学化工、环境保护、生命科学和临床医学等领域有着重要的意义。对磷酸根离子敏感电极的研究和探索...  相似文献   
67.
The intercalation of some amines (aniline, benzylamine, cyclohexylamine,piperidine, pyridine, pyrazine and piperazine) into -titaniumphosphate, Ti(HPO4)H2O,has been investigated by the batch method and/or by exposing the host to thevapour of the amines. The changes in the interlayer distance of the solidduring the intercalation process was followed by X-ray powder diffraction.The new intercalates were characterised by chemical and thermal analysis.Materials with a monolaminar and/or bilaminar arrangement of amine moleculesin the phosphate interlayer region are obtained depending on the nature ofthe amine. Due to steric hindrance, saturated phases are not obtained forall amines studied. The thermal decomposition of the intercalates (nitrogenatmosphere), takes place in three stages: dehydration, removal of amines andcondensation of the hydrogenphosphate to pyrophosphate groups.  相似文献   
68.
Quartz-homeotypic gallium (ortho-) phosphate, GaPO4, is of special interest for resonator applications asking for temperature compensated cuts with higher electro-mechanical coupling than quartz and operational temperatures up to 970°C. The crystal microbalance technique, well known for quartz (QCM) which can be used only at moderate temperatures, can now be extended to much higher temperatures using GaPO4 crystals, benefiting from all three advantages mentioned above. Two different experiments were done to demonstrate the advantages of a crystal microbalance based on GaPO4. First, the GaPO4 resonator was used for film thickness determination and compared with a commercial QCM. This experiment demonstrated that the measuring range can be extended by using GaPO4 resonators instead of quartz. The second experiment demonstrates the possibility for thermogravimetric analysis up to 720°C by using a new concept for resonator mounting.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   
69.
Different Fe-containing catalysts (pure Fe2O3, Fe2O3 supported on active carbon or g-Al2O3, and hydrotalcite derived Mg-Fe oxides) were examined in the dehydrogenation of propane performed in an Ar or CO2 atmosphere at 873 K. A promoting effect of carbon dioxide was found for the Fe2O3 and Fe2O3/AC samples. The catalytic results are discussed in terms of redox properties of the catalysts determined by temperature-programmed reduction (TPR). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
70.
火焰原子吸收光谱法测定天然水中微量铁的形态   总被引:3,自引:1,他引:3  
研究了用抗坏血酸为还原剂,使二价铁离子与邻菲啰啉(phen)形成螯合物,用硝基苯萃取,火焰原子吸收光谱法测定有机相中的铁。方法检出限为1.7ng·ml~(-1),回收率为98.0%~109.6%,线性范围为0~10.0μg·ml~(-1)(原水相),线性相关系数为0.9994。测定结果与ICP-AES法结果对照相对误差小于9.46%。  相似文献   
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