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在含20%乙醇的B-R缓冲溶液(V/V,pH=7.2)中,利用电分析化学方法测得双氢青蒿素氧基苯甲酰肼(dihydroartemisininoxy benzoic acid hydrazide,DBAH)在银电极上于-0.66V(vs.SCE)处有一不可逆还原峰。DBAH与被高碘酸钠氧化后的转铁蛋白(holotransferrin,Tf)结合形成电活性复合物,其还原峰峰电位由-0.16V负移至-0.84V,峰电流随DBAH和Tf浓度的增加而增加。该法测得一个Tf分子可以与3个DBAH分子连接,其结合常数为5.1×1010。紫外可见吸收光谱法测定结果与电化学测定结果相吻合。实验结果表明,Tf与DBAH共价结合形成电活性复合物。 相似文献
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In this paper, we present an analytical solution of the interaction of the nanotube (NT) with a wedge disclination dipole in nanotube-based composites. The corresponding boundary value problem is solved exactly by using complex potential functions. The explicit expression of the force exerted on disclination dipole is given by using the generalized Peach- Koehler formula. As a numerical illustration, both the equilibrium position and the stability of the disclination dipole are evaluated for different material combinations, relative thickness of an NT, surface/interface effects, and the features of the disclination dipole. The results show that as the thickness of the NT layer increases, the NT has a relatively major role in the force acting on the disclination dipole in the NT-based composite. The cooperative effect of surface/interface stresses and the NT becomes considerable as the increase of NT layer thickness. The equilibrium position may occur, even more than one, due to the influences of the surface/interface stress and the NT thickening. The influences of the surface/interface stresses and the thickness of the NT layer on the force are greatly dependent on the disclination angle. 相似文献
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吹扫捕集气相色谱法分析土壤中熏蒸剂氰与氰化氢残留量 总被引:1,自引:0,他引:1
采用吹扫捕集气相色谱法建立了土壤中熏蒸剂氰和氰化氢的分析方法,对土壤中氰和氰化氢预处理的吹扫温度、吹扫时间和吹扫载气(N2)流速进行了优化。最佳吹扫参数为:以10%H2SO4溶液作溶剂、吹扫温度80℃、吹扫时间60 min和吹扫载气(N2)流速40 mL.min-1。氰和氰化氢在0.2~10 mg.L-1质量浓度范围内线性关系良好,相关系数(r2)分别为0.999 1和0.998 3。在优化条件下,土壤中氰和氰化氢的平均回收率分别为95%和96%,相对标准偏差分别为3.6%和5.2%,检出限(S/N=3)分别为0.012、0.021 mg.kg-1,定量下限(S/N=10)分别为0.040、0.070 mg.kg-1。用100 mg.kg-1氰熏蒸土壤48 h,氰及其降解产物氰化氢在土壤中的残留量分别为0.32 mg.kg-1和5.68 mg.kg-1。该方法简便快速,精密度与准确度均符合要求,适用于土壤中氰和氰化氢残留量的检测。 相似文献
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扩展互作用速调管采用多间隙分布作用谐振腔和全金属平面结构,互作用电路短、单位长度增益高,其平面化结构特征与现代微加工工艺相兼容,已成为发展太赫兹高功率源的研究热点,进一步展宽扩展互作用速调管放大器的带宽成为拓展其应用的关键技术问题。设计了一种G波段5腔多间隙注波互作用电路,采用参差调谐技术扩展群聚段带宽和滤波器加载技术扩展输出段带宽,通过CST软件对结构参数优化和输出特性模拟仿真,结果表明:在电子注电压19 kV,电流300 mA,输入功率120 mW时,获得输出功率222 W,电子效率3.89%,增益32.67 dB,3 dB瞬时带宽达到了1.5 GHz。 相似文献
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