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71.
72.
Changsheng Zhao Binyu Yu Bosi Qian Qiang Wei Kaiguang Yang Aimin Zhang 《Journal of membrane science》2008,310(1-2):38-43
Bisphenol A (BPA) imprinted polyethersulfone (PES) hollow fiber membrane was spun using a dry–wet spinning method, the membrane was then prepared as a filter with an effective area of 200 cm2. The hollow fiber filter was employed to study the BPA transport behavior. The transport ability of the prepared hollow fiber membrane was measured using 100 μmol/l BPA aqueous solutions at a flow flux of 50 and 75 ml/min, respectively. The BPA transfer rate increased for the imprinted hollow fiber membranes due to the larger amount of binding sites, comparing with the non-imprinted one. In the present study, hollow fiber membrane and the molecular imprinting technique were combined for advanced separation and the data suggested that small molecules could transfer in the direction opposite to the concentration gradient due to different pH. 相似文献
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74.
In this paper a singularly perturbed Riccati equation is considered. The problem is solved by using a hybrid finite difference method on a Shishkin mesh. The method is composed of the midpoint upwind scheme and the backward Euler scheme based on the relation between the local mesh width and the perturbation parameter. It is proved that the scheme is almost second-order convergent, in the global maximum norm, independently of the singular perturbation parameter. Numerical experiments support the theoretical results. 相似文献
75.
Highly mesoporous spherical activated carbons (SACs) were prepared from divinylbenzene-derived polymers by ZnCl(2) activation; the effects of activation temperature and retention time on the yield and textural properties of the resulting SACs were studied. SACs thus prepared were characterized by N(2) adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), and aqueous adsorption assays. All the SACs were generated with high yield (>54%) and high mesopore fraction (around 80%). SEM and XRD analyses of SAC28 verified the presence of the disordered micrographite stacking with developed mesoporosity. Compared with conventional activated carbons, SAC28 prepared in our study exhibited a comparable adsorption capacity of 190 mg g(-1) for bisphenol A and even more excellent capacity of 330 mg g(-1) for phenol. Bisphenol A preloading significantly reduced the adsorption capacity of SAC28 for phenol due to both reduction of adsorption sites and pore blockage. 相似文献
76.
Quinn A Tjipto E Yu A Gengenbach TR Caruso F 《Langmuir : the ACS journal of surfaces and colloids》2007,23(9):4944-4949
We report the influence of polyelectrolyte (PE) multilayer films prepared from poly(styrene sulfonate)-poly(acrylic acid) (PSS-PAA) blends, deposited in alternation with poly(allylamine hydrochloride) (PAH), on film wettability and the adsorption behavior of the protein immunoglobulin G (IgG). Variations in the chemical composition of the PAH/(PSS-PAA) multilayer films, controlled by the PSS/PAA blend ratio in the dipping solutions, were used to systematically control film thickness, surface morphology, surface wettability, and IgG adsorption. Spectroscopic ellipsometry measurements indicate that increasing the PSS content in the blend solutions results in a systematic decrease in film thickness. Increasing the PSS content in the blend solutions also leads to a reduction in film surface roughness (as measured by atomic force microscopy), with a corresponding increase in surface hydrophobicity. Advancing contact angles (theta) range from 7 degrees for PAH/PAA films through to 53 degrees for PAH/PSS films. X-ray photoelectron spectroscopy measurements indicate that the increase in film hydrophobicity is due to an increase in PSS concentration at the film surface. In addition, the influence of added electrolyte in the PE solutions was investigated. Adsorption from PE solutions containing added salt favors PSS adsorption and results in more hydrophobic films. The amount of IgG adsorbed on the multilayer films systematically increased on films assembled from blends with increasing PSS content, suggesting strong interactions between PSS in the multilayer films and IgG. Hence, multilayer films prepared from blended PE solutions can be used to tune film thickness and composition, as well as wetting and protein adsorption characteristics. 相似文献
77.
Among various ionization detectors for gas chromatography(GC), the most promising one is perhaps the nonradioactive ionization detector which makes use of a microwave induced plasma(MIP). The use of MIP for gas chromatography was first studied by McCormack, et al. in 1965, Freeman developed a photoionization detector utilizing helium microwave discharge. In 1971, we developed a microwave 相似文献
78.
DEHYDROGENATIVE COUPLING OF METHANE UNDER PULSE CORONA PLASMA OVER A MnO|?/|?-A12O3 CATALYST 下载免费PDF全文
Pulse corona plasma was used as an activation method fordehydrogenative coupling of methane at the normal temperature and under' the normal pressure. The exprimental results showed that a great enhancement in the selectivity to C2 was achieved by the combination of pulse corona plasma with a y-Mn2OO3/Y-A12O3 catalyst. The distribution of C2 hydrocarbons was mainly affected by the power input and the nature of the catalyst. In addition, the gas stream direction exerted an influence upon the C2 yield, especially at higher power input. 相似文献
79.
研究了铜锆中间合金中铜、锆的测定方法。试样经高氯酸、硝酸分解后,采用电解法测定铜:分离铜后的电解液,经盐酸处理后以二甲酚橙为指示剂,用EDTA标准溶液滴定测定锆。该方法简便,具有良好的精密度和准确度,相对标准偏差分别为铜0.19%。锆0.15%。 相似文献
80.