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1.
Conductometric and cloud point (CP) measurement studies have been performed to investigate the interaction of tetradecyltrimethylammonium bromide (TTAB) and Triton® X-100 (TX-100) with ciprofloxacin hydrochloride (CFH) in different solvents over the temperature range of 295.15–315.15 K. CFH is used for the treatment of various bacterial infections. The observed critical micelle concentration (CMC) values of TTAB were found to be reduced in the presence of electrolytes (Na2SO4/Na3PO4), and this reduction proceeds with the elevation of salt concentration. The order of the CMC of TTAB follows the trend: > >. The observed CMC values of TTAB were found to increase with increasing temperature and decrease with increasing concentration of CFH in aqueous medium. The values of Gibbs free energy of micellization () for the TTAB/TTAB + CFH mixture were found to be negative, implying spontaneous micellization. The estimated CP of TX-100 decreases with increasing concentration of TX-100 in aqueous medium. The CP values first decrease with increasing concentration of CFH and then increase at higher concentration of CFH almost in all cases investigated. The values of free energy of clouding were found to be positive in all cases studied implying that phase separation of TX-100 was nonspontaneous. The other thermodynamic parameters associated with the micellization of TTAB and the phase separation of TX-100 were estimated and explained.  相似文献   
2.
Adsorption of Triton X-100 on various silica substrates has been investigated. A number of solids, including a natural quartz, this quartz washed with HCl acid and subsequently heated at 1273 K; two aerosils and one Kieselgel silicas were studied. These solids exhibit surface areas in the range of 5 to 430 m2 g?1. All the Triton adsorption isotherms display an S-shape at the adsorption temperatures studied (298 and 308 K). It has been found that the pretreatments of natural quartz (by water washing, impurities removed by acid and/or high temperature calcination) affect considerably the amounts of TX-100 adsorbed. Measurements of surface composition have been made by X-ray photoelectron spectroscopy (XPS) with particular emphasis on the presence of impurities and on the number of OH groups at the surface of the samples. The nature of the surface hydroxyl has also been studied by infrared spectroscopy. Furthermore, the specific number of hydroxyl groups on the surface of the silica samples has been determined by thermogravimetric analysis. Finally an attempt to correlate solid surface characteristics with adsorption isotherms has been developed.  相似文献   
3.
郝建庚 《钢管》1993,(5):33-34
针对定径机换辊后定径钢管所出现的质量问题,提出了成品机架的轧辊孔型不分配变形量和适当增大孔型直径的改进措施。  相似文献   
4.
采用Tritonx-100为铜、锌、铁、锰的增感剂,对高纯氯化锂中的铜、锌、铁、锰进行了原子吸收光谱分析,结果令人满意。其特征浓度铜为0.018μg.ml-1/1%吸收、锌为0.004μg.ml-1/1%吸收、铁为0.021μg.ml-1/1%吸收,锰为0.011μg.ml-1/1%吸收。  相似文献   
5.
pH传感器温度补偿模型研究   总被引:7,自引:0,他引:7  
水质pH值在线监测对提高水产品健康养殖至关重要,本文将无线传感器网络与pH值传感器相集成,设计了pH值监测的无线传感器网络系统。为克服pH值测量过程中温度对测量结果的影响,提出了一种pH传感器温度补偿模型,该模型通过pH传感器和PT100铂电阻温度传感器分别测量溶液的pH值和温度,利用最小二乘法对pH值和电压进行线性分析,建立pH传感器的温度补偿模型。实验结果表明,该补偿模型测量精度高,能够实现较精确的pH值在线监测。  相似文献   
6.
7.
介绍了台湾塑胶工业股份有限公司高密度聚乙烯(HDPE)树脂的生产装置、工艺技术、生产能力、树脂牌号及新产品开发现状,同时阐述了HDPE专用树脂的开发策略。目前,台塑公司HDPE商品牌号台塑烯的产品包括薄膜专用树脂、中空吹塑专用树脂、挤出专用树脂和注塑等用树脂等,并且产品具有单峰、双峰甚至宽峰相对分子质量分布的特性。2006年,台塑公司将调整台塑烯专用树脂的生产比例,强化产品结构而维持一定的营利水平。  相似文献   
8.
富集纯化三七皂甙Rb_3方法的研究   总被引:1,自引:0,他引:1  
研究了丙酮直接结晶法,正丁醇萃取法,HPD-100型药用大孔吸附树脂对三七皂甙Rb3的精制作用,并对它们的效果及可行性进行比较,主要从上样量,纯化效果进行优化,确定了用大孔吸附树脂是工业上的最佳条件。  相似文献   
9.
曹菊琴  汪建华  满卫东  熊礼威 《应用化工》2006,35(10):745-746,751
以H2和CH4的混合气体为气源,用微波等离子体辅助化学气相沉积法(MPECVD)在1 cm×1 cm S i(100)基体上沉积了金刚石薄膜。研究了不同的甲烷浓度对金刚石薄膜(100)织构生长趋势的影响。分别采用扫描电子显微镜(SEM),Ram an光谱对金刚石膜的表面形貌、质量进行了分析。结果表明,当基体温度为750℃,气压为4.8×103Pa,甲烷浓度为1.4%时,薄膜表面为(100)织构。  相似文献   
10.
Polycrystalline (pCVD) and single crystal (scCVD) diamond films grown from Chemical Vapour Deposition (CVD), if sufficiently pure at Raman analysis, are very good materials for beam or flux monitors inside accelerators or nuclear reactors. This is because they are very hard to damage in high radiation fields and very resistant to high temperatures. Films of pCVD diamond are, however, not so good as spectroscopy detectors due to inhomogeneities induced by their growth in grains with the consequent presence of grain boundaries which worsen their energy resolution. The latter can be significantly improved by growing scCVD diamond films onto HPHT synthetic diamond substrates. We have shown that it is possible to measure the density of defects inside diamond specimens using as probes suitable penetrating nuclear radiations. With the preliminary results reported here we'll show that, bombarding CVD diamond films grown at Roma “Tor Vergata” with energetic protons and 4He, 6Li and 12C ions produced in the accelerators of Catania laboratories, the pulse height defects are higher than those in silicon detectors and likewise well described by a power law in the deposited energy. Furthermore, we'll show that pulse heights for the same particles seem to depend on the duration of the measurement, thus exhibiting a sort of depolarization of the insulator when exposed to the electric voltage which makes it a particle detector.  相似文献   
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