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Linear, dibranched, and miktoarm amphiphiles containing both hydrophobic and fluorophilic moieties were synthesized and characterized in an attempt to elucidate the relationship between semifluorinated amphiphile structure and aggregate behavior in aqueous solution. For the linear and dibranched amphiphiles, there was an exponential decrease in critical aggregation concentration (CMC) and a logarithmic increase in core microviscosity with increasing length of the fluorocarbon segments; while the miktoarm architecture produced no notable trend in microviscosity or CMC. Furthermore, the linear and dibranched surfactants showed enhanced kinetic stability, dissociating more slowly in the presence of human serum than did either the dibranched or miktoarm amphiphiles. Finally, encapsulation studies with the hydrophobic drug paclitaxel (PTX) showed that the ability to solubilize and retain PTX increased with the presence and with the increasing size of the fluorocarbon moiety for both the linear and dibranched amphiphiles, while no such trend was observed for the miktoarm amphiphiles. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3324–3336  相似文献   
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A new diiodine substituted IDA derivative, 2,4-diiodine-6-methyl IDA (DIIODIDA) was synthesized and labeled with99mTc. It was established that99mTc-DIIODIDA had high radiochemical purity. Biodistribution and influence of bilirubin on99mTc-DIIODIDA biokinetics has been studied in rats and compared to the corresponding results for99mTc-SOLCOIODIDA. Related to99mTc-SOLCOIODIDA,99mTc-DIIODIDA has much better biliary exretion (55.18 versus 43.63%). No change of99mTc-DIIODIDA biokinetics, under influence of bilirubin was noticed. Biliary excretion of99mTc-SOLCOIODIDA has been reduced for about 60%. The protein binding of99mTc-DIIODIDA and99mTc-SOLCOIODIDA were also determined, using in vitro method of precipitation. These results showed that99mTc-DIIODIDA hepatobiliary imaging agent is superior to the presently used99mTc-monoiodine IDA derivatives.  相似文献   
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章新友  L.J. Li  黄永畅 《物理学报》2014,63(19):190301-190301
本文获得了有各种相互作用的一般n阶特征量泛函,其耦合系数反映了不同特征量泛函之间的耦合强度.依据定量因果原理,导出了一般n阶特征量泛函的变分原理,获得了一般n阶特征量泛函的Euler-Lagrange方程,它的不同系数可拟合不同的物理现实,如从线性到任意n阶非线性物理系统,使复杂难解的任意n阶非线性物理系统变得具体可解.并获得了该对称变换下不变的m个的守恒量,以及它们之间的关系和统一描述.依据定量因果原理导出了相对性原理,证明了绝对加速参考系、牵连参考系和相对参考系的力都有来自加速度和质量变化的贡献.利用定量因果原理自然导出了广义牛顿第一定律和广义牛顿第二定律,而且还导出了一个新定律,即广义牛顿第三定律,亦即平移不变性系统合力为零定理.进而将研究结论应用于对银河系的修正引力势、分子势、夸克禁闭势等,且其结果与物理实验一致.  相似文献   
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All solvable Lie algebras with Heisenberg nilradical have already been classified. We extend this result to a classification of solvable Leibniz algebras with Heisenberg nilradical. As an example, we show the complete classification of all real or complex Leibniz algebras whose nilradical is the 3-dimensional Heisenberg algebra.  相似文献   
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A method is presented whereby the absolute and relative stabilityof linear control systems containing transport lag can be determined.As a result feedback systems with variable time delay and loopgain, may be investigated in straightforward manner.  相似文献   
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Summary A simple theory to account for the reciprocal relationship between concentration of solute and the charge on a droplet ejected as a rising bubble bursts at a solution's surface is proposed. Reasonable agreement is found between theoretical predictions of charge in multivalent electrolytes and the experimental values. Application to continuous analysis of flowing systems and to end-point detection is demonstrated for acidbase and compleximetric titrations.
Gasblasenladung als analytisches Hilfsmittel
Zusammenfassung Eine Theorie wird vorgestellt, die die reziproke Beziehung zwischen der Konzentration des Gelösten und der Ladung erklärt, die an Tröpfchen entsteht, die beim Platzen aus Flüssigkeiten aufsteigender Gasblasen gebildet werden. Allgemeine Übereinstimmung von Theorie und Experiment wurde für verschiedene mehrwertige Elektrolyte festgestellt. Die Anwendung dieses Prinzips zur kontinuierlichen Analyse fließender Systeme sowie zur Endpunktsbestimmung von Säure-Base- und komplexometrischen Titrationen wird beschrieben.
Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany.  相似文献   
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By applying a transverse magnetic field B( perpendicular) of sufficient strength to the uniaxial molecular magnets Fe8 and Mn12, the tunneling splitting Delta(t) of their S = +/-10 magnetic ground states can be made large compared to perturbations such as hyperfine and dipolar interactions. We present evidence for such a Delta(t) from magnetic specific heat data below 1 K that is consistent with coherent quantum mechanical tunneling in a "mesoscopic" system under such conditions.  相似文献   
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The particle size distribution within an aerosol containing refractory nanoparticles can be inferred using time-resolved laser-induced incandescence (TR-LII). In this procedure, a small volume of aerosol is heated to incandescent temperatures by a short laser pulse, and the incandescence of the aerosol particles is then measured as they return to the ambient gas temperature by conduction heat transfer. Although the cooling rate of an individual particle depends on its volume-to-area ratio, recovering the particle size distribution from the observed temporal decay of the LII signal is complicated by the fact that the LII signal is due to the incandescence of all particle size classes within the sample volume, and because of this, the particle size distribution is related to the time-resolved LII signal through a mathematically ill-posed equation. This paper reviews techniques proposed in the literature for recovering particle size distributions from TR-LII data. The characteristics of this problem are then discussed in detail, with a focus on the effect of ill-posedness on the stability and uniqueness of the recovered particle size distributions. Finally, the performance of each method is evaluated and compared based on the results of a perturbation analysis. PACS  44.05.+e; 47.70.Pq; 78.70.-g; 65.80.+n; 78.20.Ci  相似文献   
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