136 resultados para propyl gallate(PG)
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IEECAS SKLLQG
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A bifunctional reagent of 3-(triethoxysilyl)propyl isocyanate (TEPI) was initially adopted as a spacer reagent to prepare the bonded types of chiral stationary phases (CSPs) with cellulose derivatives. The silica-based CSPs were chemically prepared with non-regioselective and regioselective approaches and their chiral resolving capabilities were evaluated in terms of HPLC resolution of test enantiomers. It was observed that the chiral recognition capabilities of the non-regioselectively prepared CSPs were influenced by the amount of TEPI used. And also, the regioselectively prepared CSP generally showed a slightly higher resolution power than the non-regioselectively prepared CSP, while the non-regioselective procedures were highly advantageous to rapid preparation. In addition, chiral recognition of the prepared CSPs was affected by the properties of the used silica matrices. (C) 2003 Elsevier B.V. All rights reserved.
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Nano/microstructure of bis(propyl)triethoxysilane substituted perylenediimide (1) with nanoparticle and twisted microrod morphologies were obtained by reprecipitation method induced by water and petroleum ether, respectively. It is believed that the different nucleation and growth processes involved are responsible for the formation of the nano/micro-structure With different morphologies of 1. UV-vis absorption and photoluminescence measurements show that their UV-vis absorption and photoluminescence properties are different from each other as well as their monomer mid bulk materials due to the different effects on the change transfer (CT) transition energy levels caused by their different aggregation behaviors.
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Eight new compounds of (GeCH2CH (CH3) COOAr)(2)O-3 type were synthesized. Four of them were tested for antitumor activities against Hela cells in vitro, showing considerable tumor inhibitory activities.
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The geneswere cloned for the two apoprotein subunits, alpha and beta, of phycocyanin from the cyanobacterium Spirulina maxima (=Arthrospira maxima) strain F3. The alpha- and beta-subunit gene-coding regions contain 489 bp and 519 bp, respectively. The beta-subunit gene is upstream from the alpha-subunit gene, with a 111-bp segment separating them. Similarities between the alpha-subunits of S. maxima and nine other cyanobacteria were between 58% and 99%, as were those between the beta-subunits. The maximum similarity between the alpha- and beta-subunits from S. maxima was 27%.
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As the first arrival of seismic phase in deep seismic sounding, Pg is the important data for studying the attributes of the sedimentary layers and the shape of crystalline basement because of its high intensity and reliable detection. Conventionally, the sedimentary cover is expressed as isotropic, linear increasing model in the interpretation of Pg event. Actually, the sedimentary medium should be anisotropic as preferred cracks or fractures and thin layers are common features in the upper crust, so the interpretation of Pg event needs to be taken account of seismic velocity anisotropy. Traveltime calculation is the base of data processing and interpretation. Here, we only study the type of elliptical anisotropy for the poor quality and insufficiency of DSS data. In this thesis, we first investigate the meaning of elliptical anisotropy in the study of crustal structure and attribute, then derive Pg event’s traveltime-offset relationship by assuming a linear increasing velocity model with elliptical anisotropy and present the invert scheme from Pg traveltime-offset dataset to seismic velocity and its anisotropy of shallow crustal structure. We compare the Pg traveltime calculated by our analytic formula with numerical calculating method to test the accuracy. To get the lateral variation of elliptical anisotropy along the profiling, a tomography inversion method with the derived formula is presented, where the profile is divided into rectangles. Anisotropic imaging of crustal structure and attribute is efficient method for crust study. The imaging result can help us interprete the seismic data and discover the attribute of the rock to analyze the interaction between layers. Traveltime calculation is the base of image. Base on the ray tracing equations, the paper present a realization of three dimension of layer model with arbitrary anisotropic type and an example of Pg traveltime calculation in arbitrary anisotropic type is presented. The traveltime calculation method is complex and it only adapts to nonlinear inversion. Perturbation method of travel-time calculation in anisotropy is the linearization approach. It establishes the direct relation between seismic parameters and travetime and it is fit for inversion in anisotropic structural imaging. The thesis presents a P-wave imaging method of layer media for TTI. Southeastern China is an important part of the tectonic framework concerning the continental margin of eastern China and is commonly assumed to comprise the Yangtze block and the Cathaysia block, the two major tectonic units in the region. It’s a typical geological and geophysical zone. In this part, we fit the traveltime of Pg phase by the raytracing numerical method. But the method is not suitable here because the inefficiency of numerical method and the method itself. By the analytic method, we fit the Pg and Sg and get the lateral variation of elliptical anisotropy and then discuss its implication. The northeastern margin of Qinghai-Tibetan plateau is typical because it is the joint area of Eurasian plate and Indian plate and many strong earthquakes have occurred there in recent years.We use the Pg data to get elliptical anisotropic variation and discuss the possible meaning.
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A supported lanthanum gallate (LSGM) electrolyte thin-film solid oxide fuel cell with Ni-YSZ cermet anode and strontium-doped lanthanum manganite (LSM)-yttria stabilized zirconia (YSZ) composite cathode was, for the first time, fabricated and tested. The cell was prepared by an unconventional approach, in which an LSGM thin film (about 15 mum thick) was first deposited on a porous substrate such as a porous YSZ disk by a wet process and sintered at a high temperature (above 1400degrees C). NiO was then incorporated into the porous substrate by a carefully controlled impregnation process and fired at a much lower temperature. In this way, the severe reaction between LSGM and NiO at a high temperature, which is required for the full densification of LSGM film, can be avoided. A strontium-doped LaMnO3 (LSM)-YSZ composite cathode was screen printed on the surface of the LSGM film and then fired at 1250degrees C. The electrolyte resistances of the SOFC single cells fabricated by this approach are much lower compared to those of thick LSGM film supported cells. A maximum output power density of over 0.85 W/cm(2) at 800degreesC with H-2 as fuel and air as oxidant for a fabricated cell was achieved. (C) 2002 The Electrochemical Society.
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The phase diagram of the dodecyl dimethyl ammonium hydroxyl propyl sulfonate(DDAHPS)/1-pentanol(C5H11OH)/water ternary system has been established. It contains two isotropic monophase regions (L-1 and L-2) and a liquid crystalline region (L.C.). The isotropic phase regions have been investigated by means of Raman spectroscopy and conductivity.
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The phase behavior of liquid crystalline in the ternary system of dodecyl dimethyl ammonium hydroxyl propyl sulfonate(DDAHPS)/1-pentanol(C5H11OH)/water deuteron (D2O) has been investigated by polarizing optical microscopy, H-2 NMR spectroscopy methods. The results indicate that two kinds of liquid crystals (the lamellar, and the hexagonal) exist in the liquid crystalline phase region. In this paper, we also use the polarized Raman spectroscopy method to measure the values of the order/disorder parameters and the values of the environment polarity parameters for the samples selected from the liquid crystalline phase region, and compare these two parameters of the samples with those of solid state DDAHPS and liquid state pentan-1-ol.
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A linear stability analysis is applied to determine the onset of oscillatory thermocapillary convection in cylindrical liquid bridges of large Prandtl numbers (4 <= Pr <= 50). We focus on the relationships between the critical Reynolds number Re-c, the azimuthal wave number m, the aspect ratio F and the Prandtl number Pr. A detailed Re-c-Pr stability diagram is given for liquid bridges with various Gamma. In the region of Pr > 1, which has been less studied previously and where Re, has been usually believed to decrease with the increase of Pr, we found Re-c exhibits an early increase for liquid bridges with Gamma around one. From the computed surface temperature gradient, it is concluded that the boundary layers developed at both solid ends of liquid bridges strengthen the stability of basic axisymmetric thermocapillary convection at large Prandtl number, and that the stability property of the basic flow is determined by the "effective" part of liquid bridge. (c) 2008 Published by Elsevier Ltd on behalf of COSPAR.