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61.
在pH=3.8的磷酸柠檬酸盐缓冲体系中,铟(Ⅲ)-向红菲(口罗)啉络合物在单扫描示波极谱仪上于-0.67 V(vs.SCE)处产生一灵敏的吸附还原波,其二阶导数波灵敏度高,波形好.峰电位Ⅰ~O_P与钢(Ⅲ)浓度在 2.0X10~(-8)~2.0X10~(-6)mol/L范围内呈良好的线性关系,其检测限为8X10~(-9)mol/L铟(Ⅲ).该法用于试剂氧化锌和镀膜玻璃中铟(Ⅲ)的恻定,结果较好.  相似文献   
62.
徐毅  瞿建国  张经 《分析化学》2007,35(6):877-879
以Mg(OH)2共沉淀和阳离子交换树脂作为离线预富集方法,建立了天然水体中溶解态硅电感耦合等离子体质谱(ICP-MS)测定方法。实验采用NaOH作为Mg(OH)2沉淀引发剂,以共沉淀方式将溶解态硅元素从天然水体中分离富集,再利用阳离子交换树脂将基体Mg2 清除,并对洗脱液流速、共沉淀碱度等条件进行优化选择。结果显示:Mg(OH)2共沉淀步骤可定量回收溶解态硅,控制溶液通过阳离子交换树脂的速率可将硅元素与基体Mg2 完全分离而不会造成损失。不同基体的水样的加标回收率为99%~105%,方法检出限为4.5μg/L(3S,n=8),方法精密度RSD小于3%。  相似文献   
63.
In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contactangle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorptionamount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly withincreasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both thehydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.  相似文献   
64.
本文报道了Mx[GaW9M3O40]nH2O(M′=Mo,V,Ti,Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ);M=k,Na,Gua,Me4N,Et4N,Bu4N)的合成。通过元素分析,阴离子电荷的确定,极谱、IR及UV光谱、可见光谱、ESR、磁化率测定对其进行了表征。并研究了它们在水溶液中对酸碱的稳定性  相似文献   
65.
Zhao H  Qu ZR  Ye Q  Wang XS  Zhang J  Xiong RG  You XZ 《Inorganic chemistry》2004,43(6):1813-1815
The reaction of Cu(CH(3)CN)(4)ClO(4) with 2-pyridylacrylic acid (2-HPYA) affords an unusual mixed-valence Cu(I)-Cu(II) 3-D framework ([Cu(II)(2-PYA)(2)](3).[Cu(I)(2-PYA)](2).(H2O)(2))n (1) with a novel topology which features Cu(II) dimeric units (or paddle-wheel unit). The almost perpendicular coordinating direction between the N atom of pyridyl and the O atom of carboxylate groups may be responsible for the formation of such a novel network.  相似文献   
66.
The action of three kinds of the selenomorpholine compounds on a strain ofEscherichia coli was studied by microcalorimetry. Differences in their capacities to affect the metabolism of this bacterium were observed. The extent and duration of the effect on the metabolism as judged from the rate constant (k) of Escherichia coli (in log phase) varied with the different drugs. The kinetics show that selenomorpholine compounds had an effect on the metabolism process of Escherichia coli. The k of Escherichia coli in the presence of the drugs increased with the increasing concentrations of the drugs (C) at low concentration; but at high concentration, the rate constant decreased with the increasing concentrations of the drugs. The experimental results reveal that the sequence of antibiotic activity of selenomorpholines is: N-selenomorpholinemethyl succinimide and its hydrochloride>N-(α-selenomorpholinebenzyl) succinimide. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
67.
The triplet channel in the photodissociation of ozone in the Hartley band, O3 + hv-->O(3P) + O2(3sigma), is investigated by means of a classical trajectory surface hopping method using ab initio diabatic potential energy surfaces for the B and the R states. Because of the strong recoil in the R state along the breaking O-O bond, O2(3sigma) is produced with a high rotational energy. The nonadiabatic transition probability depends markedly on the coordinate along the crossing seam. As a consequence a unique correlation is found between the internuclear geometry at the crossing and the final vibrational state of O2(3sigma). The calculated distribution of the translational energy is in good accord with the measured distribution.  相似文献   
68.
The calculations of clusters modeling the fluorine-doping and oxygen deficiency of YBa2Cu307 have been performed by the method of all-electronab initio Hartree-Fock with self-consistent crystal field. Results show that in CuO planes electric charge significantly increases, the chemical valence of Cu decreases and the covalent bonding of Cu-O greatly weakens owing to oxygen deficiency, while the effect of F restores the local electronic structure of YBa2Cu3O7. The reported opinion that F occupied the oxygen vacancy in Cu-O chains seems disputable according to the calculated bonding characteristics Project supported by the National Natural Science Foundation of China.  相似文献   
69.
本文报道了一种新的三缺位杂多阴离子α-[GaW_9O_(34)H_2]~(9-)的钠、钾、四甲基铵盐的合成方法,并通过元素分析、红外、紫外、极谱、热分析等方法对它进行了表征。α-[GaW_9-O_(34)H_2]~(9-)是一具有三个空位的杂多阴离子,它能与过渡金属离子反应生成具有Keggin结构的三取代钨镓杂多阴离子[GaW_9O_(37)M_3(H_2O)_3]~(R-)。  相似文献   
70.
Microwave irradiation was firstly attempted for the preparation of organic-based monoliths of poly(styrene-divinylbenzene- methacrylic acid), which single step in situ polymerization was carried out during 15 min. The colunm permeability, electrophoretic and chromatographac behaviors were comparatively evaluated using pressure-assisted CEC, GEC and low pressure-driven separation modes. The largest theoretical plates for the preparing column could be close to 18,0000 plates/m for thiourea in the mode of p-CEC. It provided a viable alternative to traditional initiation means for the perparation of monolithic capillary columns.  相似文献   
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