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51.
聚醚醚酮微结构及反应特性的量子化学研究 总被引:1,自引:1,他引:1
利用AM1对聚醚醚酮重复单元进行条件优化,得出了此分子的最优构型,明确了聚醚醚酮分子链的微观构象,并在此构象基础上进行量子化学计算,给出了健序、净电荷、前线轨道等信息,从理论上研究了聚醚醚酮的磺化反应及热分解反应的一些特性. 相似文献
52.
53.
l,l′-dimethylferricinium (DMFe+),a stable and pH-insensitive blue dye, was prepared via enzymatic oxidation of a 1,1′-dimethylferrocene (DMFe):2-hydroxypropyl-β-cyclodextrin
(HPCD) watersoluble inclusion complex, using bilirubin oxidase immobilized onto porous aminopropyl glass beads via glutaraldehyde
activation. In the presence of glucose, DMFe+ was reduced to DMFe by reacting with the reduced glucose oxidase (FADH2), and the absorbance decrease was followed at 650 nm. In acetate pH 5.2 buffer, the response to glucose in blood serum was
nonlinear, especially in the low concentration range, because of a competition for the reduced glucose oxidase between the
DMFe+ dye and oxygen. At this pH, endogenous ceruloplasmin was also observed to oxidize residual DMFe (16%) in the dye preparation,
causing an increase in absorbance at 650 nm. An assay protocol was then developed using maleate buffer, pH 6.5, to overcome
these interferences as well as mutarotation of α-D-glucose. The results obtained for glucose in the blood serum samples agreed
well with those of the reference hexokinase/glucose-6-phosphate dehydrogenase method. 相似文献
54.
新型含氟聚芳醚酮的合成与表征 总被引:10,自引:0,他引:10
聚芳醚酮具有很高的热稳定性和优良的电性能及机械性能 ,已经被广泛应用于宇航、电子及核能等高技术领域 [1] .氟元素的引入可以降低材料介电常数、折光指数和吸水率 ,提高热稳定性、溶解性和阻燃性 ,增加材料透明度 ,使这类聚合物在光电子、光学和微电子等应用领域的研究倍受关注 [2~ 4 ] .本文在合成含三氟甲基苯侧基的聚芳醚酮 [5] 的基础上 ,设计并合成了新型的含氟量更高的单体和聚合物 ,并对其性能进行了初步研究 .1 实验部分1 .1 试剂与仪器 [3,5 -二 (三氟甲基 ) ]苯代对苯醌 (自制 ) ;锌粉 ,A.R.级 ,天津化学试剂一厂产品 ;… 相似文献
55.
56.
纳米CoHCF修饰电极的制备及其对血红蛋白的电化学测定研究 总被引:1,自引:0,他引:1
A cobalt hexacyanoferrate (CoHCF) nanoparticle (size ca. 60 nm) chemically modified electrode (CME) was fabricated and the electrochemical behavior of hemoglobin (Hb) at this nanosized CoHCF CME was studied. In comparison with a bare glassy carbon electrode (GCE) and a general CoHCF CME electrodeposited in a traditional manner, the present nanosized CoHCF CME performed efficiently electrocatalytic reduction for Hb with relatively high sensitivity, stability, and longlife, Combined with liquid chromatography (LC), the nanosized CoHCF CME was used as the electrochemical detector of Hb in the established flow injection analysis-electrochemical determination (FIA-ECD) system. The peak current was a linear function of concentrations in the range from 2.5×10^-8 to 5.0×10^-6mol/L for Hb, with detection limit of 1.4×10^-8 mol/L. The FIA-ECD system has been successfully applied to assess the Hb content of clinic blood samples with advantages of sensitiveness, speediness, easy control and small sample-consumption. 相似文献
57.
Hydrogen peroxide in basic media is proposed as a means for dissolving whole blood samples to be analyzed by electrothermal atomization atomic absorption spectrometry, ET AAS. Approximately 2 g of the whole blood sample were directly weighed in a 150 mL volumetric flask; 3 mL of a NaOH 0.2 mol L−1 solution, two drops of 1-octanol, as an antifoaming agent, and 1 mL of 30% volume hydrogen peroxide were added to the flask to promote oxidation. The solution was then manually shaken and after approximately three minutes of shaking, a clear solution, with no apparent suspended solids or greasy layers, was obtained. Distilled-deionized water was used to complete the volume. Ten μL of the resulting solution along with 10 μL of a solution containing 5000 mg L−1 of NH4H2PO4 and 300 mg L−1 of Mg(NO3)2 as a modifier, were injected into transversely heated graphite tubes for lead determination. Both aqueous standards and standard addition calibration curves produced results not significantly different at a 95% confidence limit level. Accuracy of the measurements was assessed by analysis of the IAEA A-13 (concentration of trace and minor elements in freeze dried animal blood) standard reference material containing 0.18 mg L−1 lead on a dry basis and by means of recovery tests. Analysis of the IAEA A-13 standard produced 0.17 ± 0.02 mg L−1 lead on a dry basis; recovery tests afforded values from 95 to 105%. Ten consecutive measurements of a 5 ppb lead solution gave a characteristic mass of 47.2 pg and a (3S) detection limit of 1.77 μg L−1 Pb. Results obtained from analysis of whole blood samples of volunteer donors covered a lead concentration range between 8 and 21 μg L−1 with a mean value of 11.9 ± 4.7 μg L−1. 相似文献
58.
The first part of the paper deals with a critical discussion of the methodical basis of essential work of fracture (EWF) concept with respect to the specimen geometry (especially the notch depth) and application to polymers. In the second part, an in situ testing device, which combines a tensile testing machine with an optical strain-field measuring system, has successfully demonstrated possibility of characterization of fracture behaviour of polystyrene-polybutadiene block copolymers and block copolymer/homopolymer blends as examples of nanostructured polymer materials. It has been shown that knowledge of the time evolution of the strain field close to the crack tips leads to a simple verification of the basic precondition for the applicability of the EWF concept, the precondition “plastic zone coalescence-before-stable crack propagation”. 相似文献
59.
含间苯基聚芳醚酮的合成与性能研究 总被引:3,自引:0,他引:3
含间苯基聚芳醚酮的合成与性能研究林权,张万金,吴忠文,尹玖梅(吉林大学化学系,长春,130021)(中国科学院长春应用化学研究所)关键词聚芳醚酮,间苯基,熔点,结晶度聚芳醚酮作为一类耐高温特种工程塑料,由于具有优异的热、电、机械性能,已被广泛应用于电... 相似文献
60.
血橙中微量元素的测定 总被引:2,自引:0,他引:2
采用电感耦合等离子体原子发射光谱仪(ICP-AES),对血橙果肉汁、皮、籽中10种微量元素进行了测定。结果表明,血橙果肉汁、皮、籽中含有Ca、Mg、Fe、Zn、Mn、Cu、Ni等丰富的人体必需微量元素,且血橙果皮、籽中的微量元素含量普遍高于果肉汁中的微量元素的含量,这为血橙药效功能的进一步研究和资源综合开发利用提供一定的科学依据。 相似文献