排序方式: 共有30条查询结果,搜索用时 15 毫秒
21.
22.
23.
TiO2-loaded activated carbon fibers (ACF) were prepared by a hydrothermal method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry and UV-vis diffuse reflectance spectra (DRS). SEM images showed that the TiO2 nanoparticles were deposited on the surface of ACF, and the particle size and loading amount of TiO2 were varied by changing the initial concentration of tetrabutyl titanate (TBOT). The results of an ash experiment showed that the loading amounts of TiO2 were 18.4%, 43.3%, 52.5%, 75.1%, and 91.1% for initial concentrations of TBOT of 0.07,014, 0.21,0.28, and 0.35 tool/L, respectively, Physical interactions played an important role in the formation of TiO2/ACF composite fibers that absorb UV and visible light. Compared with those of ACF, improved adsorption and photocatalytic activity toward Rhodamine B (RhB) were observed for TiO2/ACF composite fiber. The Rhodamine B could be removed efficiently by TiO2/ACF composite fibers, and the TiO2 loading amount had a significant effect on the photocatalytic activity of TiO2/ACF composite fibers. 相似文献
24.
利用CD谱对皖南尖吻蝮蛇蛇毒内抗凝血因子(ACF)的二级结构,即α-螺旋、β-折叠和无规则卷曲进行了测定,利用ChenandYang的方法计算出了它们在ACF分子内的百分比.溶液的pH值对ACF的二级结构影响不大,但当pH位于5和6时,二级结构稍稍出现了异常.这可能是由于氢离子电离引起的电荷变化带来的效应.ACF的脱钙破坏了分子内的配位结构,而使α-螺旋的百分比大大降低.尽管三价镧系离子能取代ACF中的钙离子,但是没有给ACF的二级结构带来较大的影响. 相似文献
25.
沥青基活性炭纤维复合活化工艺的研究 总被引:3,自引:0,他引:3
以沥青基炭纤维为原料,研究了用铵盐作为化学活化剂对其进行浸渍预处理,然后采用(H2O+CO2)活化的方法制备活性炭纤维,讨论了工艺条件对活性炭纤维性能的影响并通过光电子能谱XPS探讨了活化过程中炭纤维表面官能团的变化。结果表明:采用这种物理和化学复合活化工艺,可以在较高得率下提高活性炭纤维比表面积。同时浸渍处理、H2O流量、活化温度和活化时间等工艺参数显著影响活性炭纤维的比表面积和得率,优化的工艺为:经铵盐浸渍6h,炭纤维在水蒸气与CO2流量比3:1的混合气氛中900℃活化30min。XPS研究表明,活化后炭纤维表面的含氧官能团C-O明显减少,铵盐浸渍未能增加活性炭纤维表面的含氮基团。 相似文献
26.
27.
28.
活性炭纤维固相微萃取-气相色谱法测定海水中的硝基苯类和环酮类化合物 总被引:2,自引:0,他引:2
建立了自制活性炭纤维固相微萃取与气相色谱联用测定海水中6种硝基苯类和环酮类化合物的分析方法。优化的萃取条件为: 样品中加NaCl至饱和,在1500 r/min速率搅拌下,于60 ℃水浴中顶空萃取30 min,于280 ℃下解吸2 min。方法的线性范围为0.01~400 μg/L,检出限为1.4~3.2 ng/L,相对标准偏差(RSD,n6)为1.4%~7.8%。海水样品中硝基苯类和环酮类化合物的加标回收率和RSD分别为86.3%~101.8%和3.7%~7.8%。应用所建立的方法对东海近岸表层水样进行测定,其中硝基苯、1,3-二硝基苯、2,6-二硝基甲苯的质量浓度分别为0.756,0.944,0.890 μg/L。实验结果表明,该方法简便、高效、无需有机溶剂,适合于海洋水体中硝基苯类和环酮类化合物的分析。 相似文献
29.
为了深入理解双包层光纤的光场传输特性,应用耦合模理论将双包层光纤等效为相互耦合的单模光纤和环形芯光纤,研究了圆对称的双包层光纤的光场传输.通过计算单模光纤LP01模和环形芯光纤导模的耦合系数发现了环形芯光纤LP0n模的耦合系数远大于其它导模的耦合系数,且LP0n模中的高阶模比低阶模的耦合系数大.据此,应用耦合模理论计算得到了该双包层光纤的光传输特性,计算结果发现光场沿光纤轴向呈近似周期分布,且纤芯中光功率变化的平均周期随波长递增,但平均归一化功率与光纤参数紧的选择有关. 相似文献
30.
A series of uniaxial ratcheting experiments on anisotropic conductive adhesive film (ACF) were conducted under stress-control at elevated temperature using a DMA-Q800. The ratcheting behavior of ACF specimens with different hygrothermal aging times was investigated at room temperature and 120 °C. The effects of loading rate, mean stress and stress amplitude on the ratcheting behavior of unaged and aged specimens were compared. The results show that the ratcheting strains of aged specimens are smaller than those of unaged specimens under the same experimental conditions. The cycling stability of aged specimens is increased by hygrothermal aging. At room temperature, with the increase of aging time, the ratcheting strains of aged specimens increase with hygrothermal aging time when it is less than or equal to 96 h but, however, decrease when it exceeds 96 h. At 120 °C the ratcheting strains of ACF only decrease with the increase of hygrothermal aging time. Additionally, the effects of loading rate, mean stress and stress amplitude on the ratcheting behavior of unaged and aged ACF are different and their effects are weakened by hygrothermal aging. 相似文献