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201.
Dong X Wang L Zhou J Deng L Huo J Zhang C 《The journal of physical chemistry. B》2006,110(26):13045-13049
Silica with small and regular pore sizes was synthesized by hydrothermal crystallization and investigated with thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption-desorption, and scanning electron microscopy (SEM). The ethylene polymerization was carried out with the silica-supported metallocene catalyst, and the morphology of the resultant polyethylene was investigated with SEM. It was found that the silica could break up into sheet fragments instantaneously during polymerization and the polyethylene could replicate it to obtain nanosheet polyethylene. A possible formation mechanism of the nanosheet polyethylene is proposed. 相似文献
202.
The determination of inorganic phosphorus in human urine is very important, since it has diagnostic value in some clinical
cases. Here we apply a simple, sensitive and direct method to determine inorganic phosphorus in urine. This new ensemble is
prepared by adding ytterbium chloride and pyrocatechol violet in a 2:1 molar ratio in an aqueous solution of 10 mM 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic
acid buffer at pH 7.0. The addition of the urine sample turned the blue ensemble yellow and altered the UV–vis absorption
spectra. The ensemble exhibits excellent selectivity for inorganic phosphorus over other constituents of urine. We validate
the accuracy of our method by the standard procedure (molybdenum blue assay for phosphate). The detection results are basically
consistent with normal excretion of phosphate. Furthermore, we fabricated a new kind of inorganic phosphorus reagent kit,
which enables us to inspect phosphate concentrations of urine with the naked eye. Fit for all kinds of various clinic uses,
our reagent kit is a hopeful substitute for the molybdenum reagent kit.
相似文献
203.
Zhang H Huo C Zhang J Zhang P Tian W Wang Y 《Chemical communications (Cambridge, England)》2006,(3):281-283
A novel multifunctional 1,6-bis(2-hydroxyphenyl)pyridine boron bis(4-n-butyl-phenyl)phenyleneamine compound in which the hole-transporting (HT), electron-transporting (ET), and emitting (EM) components are integrated into a single molecule was synthesized and used as an emitting material to fabricate an efficient single-layer electroluminescent device. 相似文献
204.
205.
Ren J Huo CF Wen XD Cao Z Wang J Li YW Jiao H 《The journal of physical chemistry. B》2006,110(45):22563-22569
The adsorption and dissociation of thiophene on the MoP(001), gamma-Mo(2)N(100), and Ni(2)P(001) surfaces have been computed by using the density functional theory method. It is found that thiophene adsorbs dissociatively on MoP(001), while nondissociatively on gamma-Mo(2)N(100) and Ni(2)P(001). On MoP(001), the dissociation of the C-S bonds is favored both thermodynamically and kinetically, while the break of the first C-S bond on gamma-Mo(2)N(100) has an energy barrier of 1.58 eV and is endothermic by 0.73 eV. On Ni(2)P(001) there are Ni(3)P(2)- and Ni(3)P-terminated surfaces. On the Ni(3)P(2)-terminated surface, the dissociation of the C-S bonds of adsorbed thiophene is endothermic, while it is exothermic on the Ni(3)P-terminated surface. 相似文献
206.
Ag nanoparticle films (simplified as nanofilms hereafter) on Si for electrochemical ATR surface enhanced IR absorption spectroscopy (ATR-SEIRAS) have been successfully fabricated by using chemical deposition, which incorporates initial embedding of Ag seeds on the reflecting plane of an ATR Si prism and subsequent chemical plating of conductive and SEIRA-active Ag nanofilms. Two alternative methods for embedding initial Ag seeds have been developed: one is based on self-assembly of Ag colloids on an aminosilanized Si surface, whereas the other the reduction of Ag+ in a HF-containing solution. A modified silver-mirror reaction was employed for further growth of Ag seeds into Ag nanofilm electrodes with a theoretically average thickness of 40-50 nm. Both Ag seeds and as-deposited Ag nanofilms display island structure morphologies facilitating SEIRA, as revealed by AFM imaging. The cyclic voltammetric feature of the as-prepared Ag nanofilm electrodes is close to that of a polycrystalline bulk Ag electrode. With thiocyanate as a surface probe, enhancement factors of ca. 50-80 were estimated for the as-deposited Ag nanofilms as compared to a mechanically polished Ag electrode in the conventional IRAS after reasonable calibration of surface roughness factor, incident angles, surface coverage, and polarization states. As a preliminary example for extended application, the pyridine adsorption configuration at an as-deposited Ag electrode was re-examined by ATR-SEIRAS. The results revealed that pyridine molecules are bound via N end to the Ag electrode with its ring plane perpendicular or slightly tilted to the local surface without rotating its C2 axis about the surface normal, consistent with the conclusion drawn by SERS in the literature. 相似文献
207.
Xiaojun He Jinrong Wu Guangsu Huang Xiaoan Wang 《Journal of Macromolecular Science: Physics》2013,52(1):188-200
Dynamic mechanical analysis (DMA) is used to investigate the effect of alkyl side chain length on the relaxation behavior of poly(n-alkyl acrylates) (PnAA) and poly(n-alkyl methacrylates) (PnAMA) above the glass transition temperature (Tg). Master curves and shift factors (log aT) were obtained using the time–temperature superposition (TTS) principle. The log aT curves of PnAA and PnAMA exhibit a dynamic crossover from one Vogel–Fulcher–Tammann–Hesse (VFTH) equation to another above Tg. The corresponding temperature was designated as the dynamic crossover temperature (Tc). It is found that Tc/Tg and the apparent activation energy (Eg) increases, e whereas the fragility index (m) decreases with increasing alkyl side chain length. Further analysis shows that m ∝ Tg, Eg∝ , and Eg∝ m2 for both PnAA and PnAMA. 相似文献
208.
We propose a wavelet-based method for determining optimal sampling positions and inferring underlying functions based on the samples when it is known that the underlying function is Lipschitz. We first propose a Lipschitz regularity-based statistical model for data which are sampled from a Lipschitz curve. And then we propose a wavelet-based interpolation method for generating a Lipschitz curve given a set of points, and derive the optimal sampling positions. 相似文献
209.
The behaviors of lead zirconate titanate (PZT) deposited as the dielectric for high-voltage devices are investigated experimentally and theoretically. The devices demonstrate not only high breakdown voltages above 350 V, but also excellent memory behaviors. A drain current-gate voltage (ID-VG) memory window of about 2.2 V is obtained at the sweep voltages of ±10 V for the 350-V laterally diffused metal oxide semiconductor (LDMOS). The retention time of about 270 s is recorded for the LDMOS through a controlled ID-VG measurement. The LDMOS with memory behaviors has potential to be applied in future power conversion circuits to boost the performance of the energy conversion system. 相似文献
210.
The Cauchy problem of one dimensional fourth-order nonlinear Schrödinger equation related to the vortex filament is studied. Local well-posedness for initial data in H s (?) (s > 1/2) is obtained without conditions ν < 0 and μ ? ν/2 = 0 by the Fourier restriction norm method. The result is a refinement of our previous paper (Huo and Jia, 2005). 相似文献