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211.
氯化钙/水-醇溶液稀释热 总被引:3,自引:0,他引:3
电解质溶液稀释热是溶液的重要热性质之一.由它可计算不同浓度下电解质的溶解热、表现相对摩尔焓、溶液中反应热和化合物生成热等.在电解质溶液理论研究中,稀释热也是重要的基础数据.由稀释热可推算溶液中组分的活度系数、渗透系数、相对偏摩尔焓及表观摩尔热容等[1-3].在化工生产中,稀释热是化工过程能量计算不可缺少的数据.电解质水溶液稀释热已有不少研究[2,4].但电解质混合溶剂体系稀释热报导甚少.随着加盐精馏技术、海水淡化技术等研究的进展,急需这方面数据.本文作者已报告了CaCl2/C2H5OH-H2O体系[5]和CaCl2/n-C… 相似文献
212.
A series of new complexes of formula Ln(acac)_s(Ph_3PO)_3 (where Ln~(3+)=Nd~(3+), Sm~(3+), Eu~(3+), Tb~(3+), Ho~(3+)) have been prepared and characterized. The coordination of two ligands with lanthanide ions are studied by IR spectra, ~1H, ~(13)C, ~(31)P-NMR and metal-ligand charge tranafer tranaition is also discussed via electronic adaorption and luminescence spectroscopy. 相似文献
213.
A novel thin-layer amperometric detector (TLAD) based on chemically modified ring-disc electrode and its application for simultaneous measurements of nitric oxide (NO) and nitrite (NO2−) in rat brain were demonstrated in this work. The ring-disc electrode was simultaneously sensitive to nitric oxide (NO) and nitrite (NO2−) by modifying its inner disc with electropolymerized film of cobalt(II) tetraaminophthalocyanine (polyCoTAPc)/Nafion and its outer ring with poly(vinylpyridine) (PVP), respectively. The ring-disc electrode was used to constitute a novel TLAD in radial flow cell for simultaneous measurements of NO and NO2− in rat brain combined with techniques of high performance liquid chromatography (HPLC) and in vivo microdialysis. It was found that the basal concentration of NO in the caudate nucleus of rat brain is lower than 1.0×10−7 mol l−1, NO2− concentration is 5.0×10−7 mol l−1 and NO exists in brain maybe mainly in the form of its decomposed product. 相似文献
214.
Li BS Kang SZ Cheuk KK Wan L Ling L Bai C Tang BZ 《Langmuir : the ACS journal of surfaces and colloids》2004,20(18):7598-7603
In the present work, we investigated self-assembling of a poly(phenylacetylene) carrying L-valine pendants (PPA-Val) in a water/methanol solution, upon evaporation of the solution on mica, and on the water surface. With intercalation of a fluorescence probe of Ru(phen)2(dppx)2+ (phen = 1,10-phenanthroline, dppx=7,8-dimethyldipyridophenazine) into the hydrophobic cavities associated by the PPA-Val chains, their helical structures were directly detected in solution with an in situ fluorescence microscope. Helical aggregates were observed with AFM upon evaporation of the solvents, suggesting that the helical structures in the solution are the building blocks of the helical aggregates. Self-assembling structures of PPA-Val on the water surface were, however, very different from that formed upon evaporation of its THF solution on the mica surface. The polymer chains associated into a monolayer of extended fibers on the water surface, whereas superhelical fibers formed on the mica surface. Water molecules play a critical role in inducing the polymer to form diverse morphological structures in its bulk solution and on its surface. In solution, the isotropic hydrophobic effect drove the polymer chains to form superhelical aggregates, while on the water surface, the hydrophobic effect concentrated mainly on the lateral part of the polymer, thus giving a monolayer of extended fibers. 相似文献
215.
不可逆电活性药物米托蒽醌与脱氧核糖核酸的相互作用 总被引:4,自引:0,他引:4
研究了抗癌新药米托蒽醌(MXT)的电化学行为及与脱氧核糖核酸(DNA)的相互作用,推导了适用于研究不可逆电活性分子与DNA相互作用的电化学公式,运用该公式可以简便、快速地测定靶向分子与DNA的结合常数和结合位点数。实验发现,MXT与小牛胸腺DNA的结合以蒽醌母核的嵌插作用为主,同时,烃氨基侧链与骨架磷酸基团之间的静电吸引对母核起稳定作用,使化合物易于嵌入DNA的平面结构。MXT与DNA相互作用引起的峰电流的变化可以用于分析测定DNA。 相似文献
216.
Plastic microchannels (4.5 cm long) fabricated from an etched glass master were tested for high-resolution single-stranded DNA analysis. Using replaceable denaturing linear polyacrylamide as sieving matrix, one-color separation of a fragment sizing standard with single-base resolution (R > 0.5) was achieved up to 275 bases. Two-color sizing analysis of four loci short tandem repeat (STR) allelic ladder (CSF1PO, TPOX, TH01, vWA) with single-base resolution (R = 0.62) on TH01 alleles 9.3 (198 bp) and 10 (199 bp) was demonstrated. An average standard deviation of +/- 0.06 bp and +/-0.11 bp in sizing 32 alleles of the CTTv ladder was attained between runs and between channels, respectively. Four-color sequencing separation of a terminator sequencing standard showed a base-calling accuracy of 99.1% out to 320 bases in 13 min. 相似文献
217.
218.
利用傅立叶变换红外(FT-IR)和拉曼(FT-Raman)光谱研究了高浓度磷脂酰胆碱(PC)与牛血清白蛋白(BSA)的相互作用,及Eu3+对该作用的影响.FT-IR结果显示,PC/BSA混合体系中二者的相互作用主要发生在PC头部极性基团,且这一作用随BSA含量的增加而增强,作用后蛋白质二级结构中α螺旋的比例有所增加. FT-Raman光谱说明PC与BSA的相互作用影响磷脂CH链的排列有序程度. PC/BSA/Eu3+体系的红外光谱显示, Eu3+与PC的磷氧键发生了强相互作用,并使蛋白α螺旋的比例进一步增加. 相似文献
219.
三正辛胺修饰电极伏安测定痕量金的研究 总被引:3,自引:0,他引:3
用化学修饰电极伏安测定痕量金,Kalcher K等曾采用阴离子交换剂碳糊修饰电极及打萨宗碳糊修饰电极检测100~300μg/L的金。本文采用三正辛胺(TOA)修饰玻碳电极,在1.5 mol/L介质中,Au(Ⅲ)在+0.16 V(vs SCE)处有一灵敏的不可逆还原峰。检出限为0.1μg/L。灵敏度比文献方法高千倍。Au(Ⅲ)浓度在5×10~(-7)~5×10~(-9)mol/L范围内峰高与浓度 相似文献
220.
In this review, we check out the number of published literature in the field of ECL biosensors trends during nearly a decade, and compare the research status of four different types of biosensors; summarize the application forms of nanomaterials in ECL biosensor. We have an overview of the building patterns and application example of the four main types of biosensors in the paper. 相似文献