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采用水热法在铁铬铝合金片载体上原位合成了MCM-22沸石膜,并采用X射线衍射和扫描电子显微镜对沸石膜进行了表征,探讨了成膜的影响因素. 结果表明,载体预处理条件对合成沸石膜的品质有较大的影响. 载体仅经碱处理后合成的沸石膜稀疏而不连续; 载体先经碱处理再经酸处理后可得到连续致密的沸石膜,且晶片取向均一; 载体预先涂覆Al2O3胶过渡层后制得的MCM-22沸石膜经超声波清洗后不会脱落,表明沸石膜与载体间的结合力增强. 此外,增大晶化母液量有利于沸石膜的生长. 相似文献
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李朋杰 李智焕 陈志强 吴鸿毅 田正阳 蒋伟 李晶 冯骏 臧宏亮 刘强 牛晨阳 杨彪 陶龙春 张允 孙晓慧 王翔 刘洋 李奇特 楼建玲 李湘庆 华辉 江栋兴 叶沿林 《原子核物理评论》2017,34(2):177-183
介绍了利用硅探测器的脉冲形状甄别进行粒子鉴别的原理。详细叙述了基于数字化方法的脉冲形状甄别的实现。采样频率和位数是数字化方法的两个重要参数。对于硅探测器信号,采用100 MS/s,12 bit的Digitizer可以满足脉冲形状甄别法对时间分辨的要求。同时对该方法粒子鉴别的特征和能量阈值做了简要的分析和对比。粒子背面入射硅探测器的所得的阈值低于正面入射的情况。例如对于氖周围的同位素,背面入射情况的阈值约为100 MeV,为正面入射情况下鉴别阈值的二分之一,相当与ΔE-E方法中ΔE探测器厚度约为60 μm情况下的阈值。最后定性讨论了硅探测器的电阻率不均匀性和沟道效应对粒子鉴别性能的影响。In this paper Pulse Shape Discrimination(PSD) for silicon detector has been briefly introduced. The emerging digital method successfully applied to detector signal processing makes digital PSD method one of the most promising particle identification methods. Sampling frequency and the number of bits are two key parameters of digital method. For silicon detector signal, adopting 100 Ms/s, 12 bit Digitizer can satisfy the time resolution requirement of PSD method. The identification characteristic and energy threshold of this method have been discussed and compared with both front injection and rear injection cases. Energy threshold with rear injection usually is much lower than that with front injection. For example, around for Neon isotope energy threshold with rear injection is about 100 MeV which is only half of the threshold with front injection, also equivalent to thickness of about 60 μm silicon detector threshold in ΔE-E method. At the end the impact of silicon detector's resistivity nonuniformity and channel effect on the identification capacity of PSD method has been discussed in detail. 相似文献
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Chen J Zhang J Han B Feng X Hou M Li W Zhang Z 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(31):8067-8074
The effect of compressed CO2 on the critical micelle concentration (cmc) and aggregation number of sodium bis-2-ethylhexylsulfosuccinate (AOT) reverse micelles in isooctane solution was studied by UV/Vis and fluorescence spectroscopy methods in the temperature range of 303.2-318.2 K and at different pressures or mole fractions of CO2 (X(CO2)). The capacity of the reverse micelles to solubilize water was also determined by direct observation. The standard Gibbs free energy (DeltaGo(m)), standard enthalpy (DeltaHo(m)), and standard entropy (DeltaSo(m)) for the formation of the reverse micelles were calculated by using the cmc data determined. It was discovered that the cmc versus X(CO2) curve and the DeltaGo(m) versus X(CO2) curve for a fixed temperature have a minimum, and the aggregation number and water-solubilization capacity of the reverse micelles reach a maximum at the X(CO2) value corresponding to that minimum. These results indicate that CO2 at a suitable concentration favors the formation of and can stabilize AOT reverse micelles. A detailed thermodynamic study showed that the driving force for the formation of the reverse micelles is entropy. 相似文献
26.
壳聚糖基多功能纳米药物载体的体外研究 总被引:1,自引:0,他引:1
制备了一种壳聚糖基多功能纳米药物载体系统, 并探讨了其体外释药性质. 合成了甲氨蝶呤-壳聚糖偶联物(MTX-CS), 甲氨喋呤(MTX)的取代度为6.3%; MTX-CS具有两亲性, 在水性介质中能自组装形成纳米粒子, 平均粒径为(269.5±18.3) nm, zeta电位为(25.7±0.9) mV. MTX-CS纳米粒子能有效包载抗血管生成药Combretastatin A-4(CA-4), 当药物/载体材料投料比为1∶4 时, 载药量为15.7%, 包封率为62.8%. 体外释放实验结果显示, CA-4释放较快, MTX释放缓慢, 有利于发挥2种药物的协同抗肿瘤作用. 相似文献
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Surfactant-directed assembly of mesoporous metal-organic framework nanoplates in ionic liquids 总被引:1,自引:0,他引:1
L Peng J Zhang J Li B Han Z Xue G Yang 《Chemical communications (Cambridge, England)》2012,48(69):8688-8690
Mesoporous MOF nanoplates were formed in surfactant-IL solutions. This method is simple, requires less energy, and is environmental friendly, and can be easily applied to the synthesis of other MOFs with different morphologies and porosities. 相似文献
29.
Formation of multiple water-in-ionic liquid-in-water emulsions 总被引:2,自引:0,他引:2
Emulsions composed of an ionic liquid (IL) 3-methyl-1-octylimidazolium hexafluorophosphate, water, and surfactant TX-100 (poly(ethylene glycol)-tert-octylphenyl) were studied by laser confocal scanning microscopy, stability determination and electrical conductivity. Multiple water-in-ionic liquid-in-water (W/IL/W) emulsions were formed around water volume fractions ~0.70. Further studies showed that the W/IL/W multiple emulsions were formed through an inversion between water-in-IL emulsion and IL-in-water emulsion. 相似文献
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