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91.
A new flow-injection chemiluminescence (CL) method for determination of chloroquine is proposed based on a stronger chemiluminescence of chloroquine in hydrogen peroxide-nitrite-sulfuric acid medium. The proposed method allows the measurement of chloroquine over the range of 3.0×10−7 to 1.0×10−5 mol l−1. The detection limit is 8.6×10−8 mol l−1, and the relative standard deviation for 1.0×10−6 mol l−1 chloroquine (n=11) is 1.6%. The CL mechanism is also discussed. 相似文献
92.
核糖核酸酶A在DAB-环乙烷溶液中的活性和构象 总被引:1,自引:0,他引:1
The activity and conformation of ribonuclerse A (RNaseA) solubilized in cyclohexane via dodecylammonium butyrate(DAB) reverse micelles were investigated. The activity of RNaseA was studied using the cytidine 2’,3’ -phosphate as the substrate, and it was found that kcat increases significantly with respect to that in water attended by an increased Km•FT-IR spectra of RNaseA in reverse micellar solution were investigated as a function of w0(= [H2O]/ [DAB]), and it was noted that the structure of RNaseA became losser in reverse micelles campared to that in aqueous solution. The relation between activity and conformation was discussed. 相似文献
93.
Flow-injection chemiluminescence determination of fluoroquinolones by enhancement of weak chemiluminescence from peroxynitrous acid 总被引:1,自引:0,他引:1
A flow-injection chemiluminescence (CL) method is described for the determination of fluoroquinolones including ciprofloxacin, norfloxacin and ofloxacin. The method is based on the enhancement by these compounds of the weak CL from peroxynitrous acid. The linear ranges are 1.0×10−7 to 1.0×10−5 mol l−1 for ciprofloxacin and norfloxacin, and 3.0×10−7 to 3.0×10−5 mol l−1 for ofloxacin, respectively. The detection limits (S/N=3) are 4.5×10−8 mol l−1 ciprofloxacin, 5.9×10−8 mol l−1 norfloxacin and 1.1×10−7 mol l−1 ofloxacin, respectively. The proposed method was applied to the determination of fluoroquinolones in pharmaceutical preparations. 相似文献
94.
95.
Water swelling rubber (WSR) was prepared by reaction blending SBR andsodium polyacrylate (PAANa). The existing states of water in the WSR was studied bymeans of DSC and TG. It was found that water exists in three states: nonfreezing water,bound freezable water and free water. The relationships between water states and structureof PAANa were investigated. The results showed that the amount of non-freezing waterwas related to total water content, and the ratio of non-freezing water versus -COONagroups on PAANa (mol/mol) was about 4. However, total water content slightly affectedthe content of bound freezable water and remarkably affected the amount of free waer. 相似文献
96.
A dinuclear manganese(II) complex, [Mn2(μ-Oac)2(phen)4](ClO4)2 1 (phen = phenanthroline), has been prepared by the reaction of Mn(Oac)2·4H2O, phen, tartaric acid and NaClO4·H2O in MeOH/H2O solution. The crystal structure has been determined by X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 9.6052(4), b = 14.2353(7), c = 18.8893(8)(A),β= 96.584(1)°, C52H38Cl2Mn2N8O12, Mr = 1147.68, V = 2565.8(2) (A)3, Dc = 1.486 g/cm3, F(000) = 1172, μ = 0.668 cm-1 and Z = 2. The final refinement gave R = 0.0605 and wR = 0.1619 for 3203 reflections with I > 2σ(I). The complex contains a dinuclear [Mn2(μ-Oac)2(phen)4]]2+ cation located at a centre of symmetry with two syn-anti acetate bridges between the Mn atoms. Each Mn atom is coordinated by four N atoms from two chelating phen ligands and two O atoms from a pair of bridging acetate groups to furnish a distorted octahedral geometry. Two ClO4 anions exist around the cation [Mn2(μ-Oac)2(phen)4]2+as counter ions. 相似文献
97.
La0.8Sr0.2Ga0.8Mg0.2O2.8的电化学性质及其在SOFC中的应用 总被引:3,自引:0,他引:3
采用凝胶浇注法制备具有较高氧离子电导率的固体电解质La0.8Sr0.2Ga0.8Mg0.2O2.8粉料.X射线衍射结果表明,于1400℃焙烧后即形成了钙钛矿结构,无杂相存在.探讨了粉料压制坯体的致密化和导电性能在1450℃下与烧结时间的关系,发现烧结时间为18h时其相对密度达98.3%,而在24h的情况下,样品具有最佳的氧离子导电性.采用Ni-Ce0.8Gd0.2O1.9作为阳极,La0.8Sr0.2Ga0.6Ni0.4O2.7作为阴极,组装了平板型固体氧化物燃料电池(SOFC).阳极和阴极分别通入含3%H2O的氢气和空气,750℃时的开路电压为1.04V,最大输出功率密度(P)达252mW/cm2(U=0.48V,J=525mA/cm2). 相似文献
98.
以表面活性剂十六烷基三甲基溴化铵(CTAB)和难溶有机颜料耐晒大红BBN(简称BBN)为双组分降解底物, 以TiO2为光催化剂, 研究双组分底物的光催化降解的快慢及规律, 双组分降解的相互影响, 初步建立双组分和催化剂之间的作用模型. 结果表明, pH值及底物的浓度对双组分体系的降解都有显著影响, 碱性条件更适合体系的降解, 在中性(pH=6.8)环境中两种底物的降解效果明显高于单组分的降解. 在碱性条件下(pH=9.2), 加入BBN使CTAB的降解速率略有下降. CTAB的浓度对BBN褪色速率影响较大, 当CTAB 的浓度为1 cmc 时, BBN和CTAB的降解速率都达到最快. BBN在TiO2表面吸附性强, 且被优先降解. 相似文献
99.
100.
本文探讨了计算机断层扫描(CT)、磁共振成像(MRI)对良恶性甲状腺结节的鉴别价值。方法:选取2015年3月至2018年3月本院收治的甲状腺结节患者150例,依据病理结果分为恶性48例、良性102例,所有患者均给予CT、MRI检查,分析CT、MRI对良恶性甲状腺结节的鉴别价值。结果发现,MRI总病灶、形态不规则、边界不清/毛糙、信号/密度不均检出率明显高于CT,MRI钙化灶检出率明显低于CT,差异有统计学意义(P<0.05),CT、MRI淋巴结转移检出率比较,差异无统计学意义(P>0.05);在鉴别良恶性甲状腺结节的敏感度、特异度、准确度中,CT为79.17%、74.51%、76.00%,MRI为83.33%、80.39%、81.33%,CT联合MRI为95.83%、96.08%、96.00%,CT联合MRI明显高于CT、MRI,差异有统计学意义(P<0.05)。说明CT、MRI可作为鉴别良恶性甲状腺结节的重要方法,CT对钙化灶有较高的分辨能力,MRI对软组织及小病灶有较高的分辨能力,CT联合MRI可有效提高其鉴别价值。 相似文献