络合萃取-在线衍生气相色谱-质谱法检测土壤中酸性除草剂

以Na4-EDTA为络合剂、五氟苄基溴为衍生试剂,对土壤中酸性除草剂进行在线衍生络合萃取,采用负化学源质谱技术对衍生产物实现了快速、高灵敏检测.将10.0 g土壤样品、1.5 mL蒸馏水、0.50 g Na4-EDTA充分混合,加入过量衍生试剂,采用加速溶剂萃取仪,样品在100 ℃,10.3 Mpa压力下,10 min...     

丁醇稀溶液的络合萃取

有机酸;烷基膦酸酯;丁醇稀溶液的络合萃取     

丁醇稀溶液的络合萃取

有机酸;烷基膦酸酯;丁醇稀溶液的络合萃取     

氟-铝络合滴定计算分析法测定乙醇-水溶液介质中的铝

导出了氟离子标准溶液滴定铝离子的络合滴定计算分析的数学模型。以氟离子选择性电极作指示电极,利用氟离子与铝离子在乙醇-水溶液中产生沉淀,仅形成3种络合物的现象,先计算出3个条件累积稳定常数,再计算出铝离子的分析浓度。通过氢氧化铝的条件溶度积常数,求出溶液控制的pH值约为4．7。讨论了滴定数据的位置对测定结果的影响。     

铟-二甲酚橙络合吸附波的研究

铟(Ⅲ)在0.03mol/l邻苯二甲酸氢钾(KHP)、5×10~(-6)mol/l二甲酚橙(XO)溶液(pH3.9)中,出现一良好的示波极谱图,峰电位E_p=-0.68V(vs.SCE),其峰电流与铟的浓度在1.0×10~(-7)～3.0×10~(-6)mol/l范围内成线性关系,检测下限为5.0×10~(-8)mol/l。用等摩尔连续变化法确定络合物的络合比为In(Ⅲ):XO=1:1。用循环伏安法等电化学手段研究极谱波的性质及其反应机理。并测定了不同铟浓度时体系的吸附量。体系的吸附符合Frumkin吸附等温式,吸附系数β=4.3×10~5,吸引因数α=-1.75。实验表明,该波属于络合吸附波。     

改性酚氧树脂/聚(甲基丙烯酸丁酯-co-4-乙烯基吡啶)共混物的相容-络合行为和表面表征

合成了一系列不同4-乙烯基吡啶含量的聚(甲基丙烯酸丁酯-co-4-乙烯基吡啶)(BVPy)共聚物,并对酚氧树脂(Phenoxy)的仲羟基进行了不同乙酰化程度的改性.用粘度法和激光光散射(LLS)研究了BVPy/改性Phenoxy共混物在溶液中的络合行为对氢键相互作用基团密度的依赖性,并用DSC研究了共混体系在本体中的相容性.将粘度法及LLS的结果结合起来,得到了改性Phenoxy/BVPy共混体系的不相容-相容-络合转变相图.在此基础上,用XPS初步考察了共混物的相容性对其表面组成的影响.结果表明,大分子间的络合相互作用可抑制共混物的表面富集.     

交流示波极谱法中电流—电位曲线的研究——Ⅲ.电流-电位曲线示波极谱络合滴定法

利用交流示波极谱法中i_f-E曲线来指示滴定终点的容量分析方法,叫做i_f-E曲线示波极谱滴定法。本文研究i_f-E曲线示波极谱络合滴定法。     

孔性介质负载下的络合氢化物及其储氢特性

络合氢化物具有较高的重量储氢密度,已成为国内外研究的热点。孔性介质由于高比表面积、孔径均匀可调以及良好热稳定性而备受关注。研究表明,实现孔性介质负载的络合氢化物可有效地改善其储氢性能。本文简述了孔性介质的结构特征和物化特性,着重阐述了孔性介质负载催化络合氢化物的制备方法、脱/加氢性能的影响及其催化机理的研究进展,并指出了需要研究的科学问题。     

铟-8-氨基喹啉络合吸附波的研究

在0.04Mol/L HAc-0.36Mol/L NaAc(pH5.7)和3.5×10~(-4)Mol/L 8-氨基喹啉(8-Aminoquinoline)溶液中,用单扫示波极谱法可得到In(Ⅲ)-8-氨基喹啉络合吸附波,峰电位在-0.78V处。其导数峰高与铟在5.0×10~(-8)-4.0×10~(-6)Mol/L范围内的浓度呈线性关系,最低检出限为2.0×10~(-8)Mol/L。研究确定该波为1∶1铟-8-氨基喹啉络合物的吸附波。测定了几种地球化学标准样品中的锢,结果满意。     

Polarographic Determination of Famotidine through Complexation with Nickel(II) Chloride

The present investigation describes the development of a sensitive, rapid polarographic method for the determination of famotidine in pure form and in certain dosage forms. The proposed method depends upon studying the polarographic activity of Nickel(II)‐famotidine complex in Britton Robinson buffer over the pH range 4–8 and its usefulness in the analysis of famotidine using direct current (DC_t), differential pulse (DPP), and alternating current (AC_t) polarography. The different experimental parameters affecting the cathodic waves were carefully investigated and optimized. Moreover, to check the validity of the proposed method, the standard addition method was applied by adding famotidine to the previously analyzed tablets. The recovery of the drug was calculated by comparing the concentration obtained from the spiked mixtures with those of the pure drug. The results of analysis of commercial tablets and the recovery study suggested that there is no interference from any excipients, which are present in tablets. Statistical comparison of the results was performed with regard to accuracy and precision using student's t‐test and F‐ratio at 95% confidence level. There is no significant difference between the comparison and proposed method with regard to accuracy and precision.     

Inclusion Complexation of Diphenylamine-4-diazonium Chloride and p-Sulfonatocalix[4]arene

Inclusion complexation of p-sulfonatocalix[4]arene (SC4A) and diphenylamine-4-diazonium chloride (DDC) in aqueous solution was investigated in this study. The inclusion of DDC in the cavity of SC4A leads to ¹H NMR chemical shifts of DDC moving towards higher magnetic field. The complexation of SC4A also results in a bathochromic shift and a decrease in optic intensity of the absorption spectrum of DDC. In the presence of SC4A, the thermal stability of DDC in aqueous solution increases significantly while its photosensitivity still remains high.     

Preparation and spectroscopic studies of PbS/nanoMCM-41 nanocomposite

The present work describes the preparation and characterization of nanosized PbS particles inside the mesopore channels of nanoMCM-41 silicate molecular sieves. The encapsulation of the lead sulfide was carried out at room temperature by ion-exchange method. Diffuse reflectance ultraviolet–visible spectroscopic studies showed a significant shift in the absorption band for the entrapped metal sulfide as compared to corresponding bulk sulfide. Thus, confirming the quantum confinement of the incorporated nanoparticles in nanoMCM-41.     

Fabrication of polystyrene–PbS core-shell and hollow PbS microspheres with sulfonated polystyrene templates

Uniform inorganic- (PbS) coated polymer core-shell and hollow PbS microspheres were prepared by an easy and economical approach. Monodisperse polystyrene (PS) microspheres were used as templates, as well as the core of the composite spheres; lead sulfide shells were obtained through the reaction of lead acetate (Pb(CH₃COO)₂) and thioacetamide (TAA) at room temperature. The morphologies and structures of the as-synthesized products were systematically characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectra (FTIR). The fluorescence property of the as-synthesized product was also investigated. A reasonable mechanism for the formation of PS–PbS core-shell and hollow PbS microspheres was discussed. According to a series of parallel experiments, effects of related experimental parameters were also carefully investigated, such as the molar ratio of Pb(CH₃COO)₂ to TAA, reaction temperature, etc.     

PbS纳米棒的水热合成与表征

以乙酸铅和硫脲为主要原料,十二烷基磺酸钠和十六烷基三甲基溴化铵为表面活性剂,在120℃反应12h,水热法制备了PbS纳米棒.并利用X射线粉末衍射(XRD)、透射电子显微镜(TEM)和高分辨电子显微镜(HRTEM)等手段对产物进行了表征,实验结果表明：产物为纯相立方结构的PbS单晶纳米棒.考察了乙酸铅和硫脲间的摩尔比以及反应温度对合成产物的影响,并初步探讨其形成机理.     

Thermodynamic Modeling of Actinide Complexation with Acetate and Lactate at High Ionic Strength

The stability constants of NpO ₂ ⁺ , UO ₂ ²⁺ Am³⁺, and Th⁴⁺ with acetate and lactate anions has been measured in 0.3–5.0m NaCl media at 25°C by the solvent extraction technique. For the 1:1 complexation, the values of the stability constants increased in the order: NpO ₂ ⁺ < Am³⁺ < ₂ ²⁺ < Th⁴⁺, in accordance with the actinide charge density and reflecting the strongly ionic bonding of the complexes. The Pitzer ionic interaction parameters were calculated and used to estimate the thermodynamic stability constants at I = 0. Because our data were collected mainly in the high ionic strength region values of ⁽¹⁾ were estimated from values reported in the literature. For all stability constants the Pitzer model gives an excellent representation of the data using three interaction parameters ⁽⁰⁾, ⁽¹⁾, and COn leave from Institute of     

双连续微乳体系中PbS纳米管的控制合成(英文)

PbS nanotubes were synthesized by the tiny water channels in bicontinuous microemulsions consisted of p-octyl polyethylene glycol phenylether (OP)/n-amyl alcohol/cyclohexane/water. The possible formation mechanism of PbS nanotubes is also discussed based on their shape evolutions. The results indicate that the formation of PbS nanotubes is probably via the process of the nucleation, growth, assemblage and crystallization.     

胆酸和L-苯丙氨酸的固相包合作用

研究了胆酸(CA)和L-苯丙氨酸(PAA)以固相熔融法形成的固相包埋配位. 通过粉末X射线衍射图、红外光谱、粉末荧光光谱及差热分析方法, 测定了固相包埋形成的CA-PAA配合物. 同时, 用溶剂共沉淀法和机械研磨法对比了CA-PAA包埋物的形成. 结果表明, 封管固相熔融时PPA以客体形式被包合进主体CA形成的通道; 研磨法中CA部分包埋PPA; 溶剂共沉淀方法中, PPA不被主体CA包埋, 而使用的相应溶剂被CA包埋.     

离聚物的缔合与络合

本语文对与离聚物材料的研究和开发相关的离聚物的缔合与络合这两个基本问题作了评述,强调了离聚物的结构与缔合和络合的影响。此外,还对由离子作用和氢键作用所导致的 事作用了比较和讨论。