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141.
Stable, reproducible nanorecording on rotaxane thin films 总被引:3,自引:0,他引:3
Feng M Guo X Lin X He X Ji W Du S Zhang D Zhu D Gao H 《Journal of the American Chemical Society》2005,127(44):15338-15339
Stable, reversible conductance transitions and memory effects were observed in solid-state rotaxane-based Langmuir-Blodgett (LB) thin films. Taking advantage of the switching property, we have achieved reproducible nanometer-scale recording dots on rotaxane LB films via voltage application using a scanning tunneling microscope probe. The stable and easily controlled conductance switching makes the rotaxanes a hopeful candidate for nanorecording. 相似文献
142.
以EGTA-Ba和SO4^2-为联合掩蔽体系,有效地消除因大量钙存在而产生的干扰。在PH10.2硼砂缓溶液中,镁与偶氮氯磷Ⅰ形成稳定络合物,用自制的双波长分光光度仪,在组合波长570nm和500nm下,用于磷矿中镁的测定。不需分离,方法简单,快速,结构满意。 相似文献
143.
全氟辛基磺酸酸度函数H0的测定 总被引:2,自引:1,他引:2
It is reported in this paper that the acidity function H_0 of perfluorooctanesulfonic acid (POSA) is -12.11±0.03, which was measured first time by ~1H NMR method, in term of the α-H chemical shifts of the acid-ether systems, using 98% to 100% H_2SO_4 as reference standards. This method provides a new procedure for measuring the H_0 value of solid perfluoroalkanesulfonie acid C_nH_(2n+1)SO_3H(n>7). 相似文献
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146.
An indirect laser photoacoustic technique is described. The basic principle, the experimental set-up and the influencing factors are discussed in detail. This method was used to quantify phenylamine, arginine and methylene blue on membranes. The linear ranges of the calibration curve are up to two orders of magnitude. With 1 microliter of sample solution, the detection limits are 0.25, 1.52 and 0.14 pmol for phenylamine, arginine and methylene blue, respectively. 相似文献
147.
148.
Xiao-pingYan Bao-linHe JieZhang Han-fanLiua 《高分子科学》2005,(4):393-399
Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate. Compared to the enantiomeric excess (e.e.) value (71.4%) obtained without the presence of metal cations, obvious e.e. enhancement (up to 82.5%) was resulted from the addition of Zn^2 but with a certain decrease in activity. The reaction parameters in the presence of Zn^2 were also studied. It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations. 相似文献
149.
Molecularly imprinted polymer membranes containing artificial recognition sites for 4-aminopyridine have been prepared by photopolymerization using 4-aminopyridine as template. Reference membranes were prepared with the same monomer mixture but in the absence of the template. The binding characteristics of the imprinted polymer membrane were investigated by a batch method and the transport properties of the membranes were investigated using diffusion chambers. The results showed that the binding amount of 4-aminopyridine is higher than that of 2-aminopyridine whereas the latter can transport the 4-aminopyridine imprinted polymer membrane faster than 4-aminopyridine. 相似文献