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901.
Zhaoyun Ding Liguo Zhou Shimin Fang 《Journal of Dispersion Science and Technology》2013,34(9):1342-1349
Effect of surfactants [polyglycerol diisostearate ethoxylates (PGDIS-E31, PGDIS-E36 and PGDIS-E40) and Tween-80], alcohols (1,2-propandiol, ethanol, 1-propanol, 1-butanol, 2-butanol and 1-pentanol), oils [isopropyl palmitate (IPP), isooctyl palmitate (IOP), dioctyl carbonate (DOC), and dioctyl hexanediate (DOH)], temperature and sodium chloride on the microemulsion formation of the surfactant/alcohol/oil/water system has been investigated by the pseudo-ternary phase diagrams. The capacities of the four surfactants in the microemulsion formation of the surfactant/alcohol/IPP/water system at surfactant/alcohol of 2:1 are in the order of PGDIS-E31 > PGDIS-E36 > Tween-80 > PGDIS-E40, whatever alcohol (ethanol, 1-propanol, and 1-butanol) is used. PGDIS-E31 and 1-butanol exhibit best synergism in the microemulsion formation. In addition, the volume, structure and polarity of oil all influence the microemulsion formation. At the optimum weight ratio 2:1 of PGDIS-E31/1-butanol, the microemulsion region of the PGDIS-E31/1-butanol/IPP/water system is the largest among the studied systems. The microemulsion system of PGDIS-E31/1-butanol/IPP/water is not sensitive to lower temperature such as 40°C. It is also not sensitive to sodium chloride when the concentration of sodium chloride is in the range of 0 to 1.0%. 相似文献
902.
Based on the J(x) fractal distribution function of aperture given by Jaroniec, this article suggests another function K(x), a variant of J(x) but offering new insight. We then use these two functions to characterize three kinds of activated carbon fiber (ACF) of different specific areas. This article also provides the fractal distribution of the aperture and the isotherm of nonpolarity benzene steam on the ACF specimens and the relationship between them. 相似文献
903.
Zhaoyun Ding Peng Zhang Zhongni Wang 《Journal of Dispersion Science and Technology》2013,34(4):495-500
A series of polyglycerol diisostearate ethoxylates with two hydrophobic chains were prepared by the reaction of polyglycerol diisostearate with ethylene oxide. Surface properties including water solubility, cloud temperature, critical micelle concentration, emulsification, and the solubilizing capacity of polyglycerol diisostearate ethoxylates for simvastatin were investigated in comparison with those of Tween‐80. The critical micelle concentrations of all polyglycerol diisostearate ethoxylates are less than 0.01 mmol l?1, which is one order of magnitude lower than that of Tween‐80. Polyglycerol diisostearate ethoxylates show better emulsification than Tween‐80. For enhancing the solubility of simvastatin in micelles, polyglycerol diisostearate ethoxylates also are superior to Tween‐80. 相似文献
904.
Wu Men Fenfen Wang Yusheng Zhang Jianhua He Wen Yu Yiliang Li 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):89-94
224Ra concentrations in the coastal sea water of western Taiwan Strait in winter were measured using Mn-fiber adsorption—successive emanation scintillation method. 224Ra activities in the seawater of the western Taiwan Strait varied from 0.90 to 16.25 Bq/m3 with an average of 4.60 Bq/m3. The horizontal and vertical distributions of 224Ra were studied. The distributions of 224Ra in the surface water decreased gradually with increasing distance offshore. The apparent horizontal and vertical eddy diffusion coefficients estimated from the one dimensional steady state model of 224Ra were (5.0–55.4) × 106cm2/s and (4.0–51.7) cm2/s, respectively. 相似文献
905.
以多孔Al2O3陶瓷为基体材料, 采用浸渍法担载NiO后用2B铅笔修饰NiO/Al2O3表面, 通过化学镀法沉积约5 μm厚的金属钯, 还原后成功制得Pd/Pencil/Ni/Al2O3膜. 为进行对比, 还制备了未担载镍的Pd/Pencil/Al2O3膜. 膜的表面和断面形貌分别采用扫描电镜和金相显微镜观测, 膜的透氢动力学通过H2/N2单气体法测试, 并以成分为H2 77.8%, CO 5.2%, CO2 13.5%和CH4 3.5%的原料氢测定了膜的氢分离效果. 结果表明, 未载镍的Pd/Pencil/Al2O3膜只具有氢分离作用, 而Pd/Pencil/Ni/Al2O3膜还可以有效地将钯膜泄漏的CO和CO2转化为甲烷, 因而成为双功能型钯膜. 这种双功能膜尤其适用于面向质子交换膜燃料电池(PEMFC)的氢气分离, 既有效解决了PEMFC对氢燃料中CO格外敏感的难题, 又提高了对钯膜缺陷的容忍度, 因而延长了钯膜的使用寿命. 相似文献
906.
Chen Li Zheng-Xi Zhou Xiao-Qiang Jia Yu Chen Jiao Liu Jian-Ping Wen 《Applied biochemistry and biotechnology》2013,171(7):1715-1725
A highly efficient oil-degrading bacteria JZX-01 was isolated from the oil-contaminated soil of the seacoast near the Boxi Offshore Oil Field of China. Morphological, physiological, and 16S rDNA gene sequence analyses indicated that JZX-01 was assigned to the genus Rhodococcus sp. This strain decomposed 65.27?±?5.63 % of the crude oil in 9 days. Gas chromatography–mass spectrometry analysis showed that even the long-chain hydrocarbons (C31–C38) and branched alkanes (pristine and phytane), which were regarded as the stubborn ones, could be degraded. Further study showed that the bacteria still has good oil degradation ability at low temperatures as well as under high salt conditions. Moreover, JZX-01 was found to have a biosurfactant-producing capacity, which significantly favors the surface tension reduction and crude oil degradation. The promising isolated strain Rhodococcus sp. JZX-01 could be further used for the bioremediation of oil-polluted soil or seawater in a wide range of temperatures and high salt conditions. 相似文献
907.
Yuedi Ding Jun Fan Wenxin Li Runlin Yang Ying Peng Lili Deng Yu Wu Qiang Fu 《Applied biochemistry and biotechnology》2013,170(7):1637-1648
Somatostatin is a natural inhibitor of growth hormone, and its analogues are clinically used for the therapy of acromegaly, gigantism, thyrotropinoma, and other carcinoid syndrome. However, natural somatostatin is limited for clinical usage because of its short half-life in vivo. Albumin fusion technology was used to construct long-acting fusion proteins, and Pichia pastoris was used as an expression system. Three fusion proteins, (somatostatin (SS)14)2-human serum albumin (HSA), (SS14)3-HSA, and HSA-(SS14)3, were constructed with different fusion copies of somatostatin-14 and fusion orientations. The expression level of (SS14)3-HSA and HSA-(SS14)3 was much lower than (SS14)2-HSA due to the additional fusion of the somatostatin-14 molecule. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry revealed that severe degradation occurred in the fermentation process. Similar to the standard of somatostatin-14, all three fusion proteins were able to inhibit growth hormone secretion in the blood, with (SS14)2-HSA being the most effective one. On the whole, (SS14)2-HSA was the most effective protein in both production level and bioactivity, and increasing the number of small protein copies fused to HSA may not be a suitable method to improve the protein bioactivity. 相似文献
908.
新型磺酸盐型Gemini表面活性剂的合成及其与聚合物相互作用 总被引:1,自引:0,他引:1
以溴代正烷烃、乙二胺、1,3-丙磺内酯合成了一系列新型磺酸盐型Gemini表面活性剂(SGS-8、SGS-10、SGS-12、SGS-14);采用IR、1H NMR及元素分析等手段对合成产物进行结构表征,并研究了其表面活性,采用等温滴定微量热技术、表面张力法和稳态荧光光谱法研究了SGS-12与聚丙烯酰胺(PAM)的相互作用规律及热力学参数。结果表明,合成的产物纯度较高,具有较低的cmc值和较好的表面活性;SGS-12/PAM混合体系的表面张力曲线和芘探针在体系中微极性的变化表明,二者发生相互作用且形成混合胶束;SGS-12与PAM结合是一个由焓驱动的自发过程,△H和△S均小于0,表明相互作用力以氢键和范德华力为主,合成产物在聚丙烯酰胺分子上的平均结合数为287。 相似文献
909.
Wei Li Chaoqin Li Zuosheng Chen Naixiu Ding Zongwei Cai 《International journal of environmental analytical chemistry》2013,93(7):691-711
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analysed in 95 mountainous and park soil samples collected from 19 sites in Beijing, China. The levels of PCDD/Fs in the mountainous soils were low (0.086–0.59; mean 0.29; median 0.23 ng I-TEQ/kg). The levels in the park soils far from the city centre were a little higher (0.39–0.88, mean0.68; median 0.75 ng I-TEQ/kg). However, in the park soils near to the city centre, there were an abrupt jump in their concentration (1.7–3.2; mean 2.3, median 1.7 ng I-TEQ/kg), about ten times higher than those in the mountainous sites. Comparison of PCDD/Fs homologues and congener compositions between possible sources and samples indicated that the mountainous and park soils in Beijing had been slightly contaminated mainly by sodium pentachlorophenate, sewage sludge, atmospheric deposition and vehicle exhaust. These results have also been supported by the principal component analysis. 相似文献
910.
Xiaodong Wen Shengchun Yang Haizhu Zhang Xia Zhao Jie Guo 《International journal of environmental analytical chemistry》2013,93(12):1243-1253
As a new developed instrument, a portable tungsten coil electrothermal atomic absorption spectrometer (W-coil ET-AAS) was first coupled with surfactant assisted dispersive liquid–liquid microextraction (SA-DLLME) to improve its analytical performance and expand its applications in this work. SA-DLLME was very simple, rapid and the extraction efficiency was considerably improved by the effect of surfactant, which was suitable to be coupled with the portable instrument in field analysis. After SA-DLLME, concentrated chromium in organic phase was directly determined on W-coil atomiser. The influence factors relevant to SA-DLLME and instrumental conditions were studied systematically. Under the optimal conditions, the limit of detection (LOD) for Cr(VI) was 0.016 µg L?1, with sensitivity enhancement factor (EF) of 107. The relative standard deviation (RSD) for seven replicate measurements of 0.5 µg L?1 of Cr(VI) was 4.6%. The recoveries for the spiked samples were in the acceptable range of 96.8–104%. The rapid, simple and high effective method greatly improved the sensitivity of this portable spectrometer for the determination of Cr(VI) and was applied to the analysis of ultra-trace Cr(VI) in real and certified water samples with satisfactory results. 相似文献