排序方式: 共有49条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
报道了一种基于含锌(II)有机配位聚合物制备微孔碳的新方法. 通过锌离子和酒石酸之间的配位作用获得含锌有机配位化合物, 并通过氢键作用将其引入到间苯二酚/甲醛低聚物溶胶的开放网络结构中. 使含锌有机配位化合物和酚醛低聚物溶胶体系发生共聚反应得到酚醛和含锌有机配位共聚物, 在950℃下热处理分解以及锌蒸气蒸发后制得微孔碳. 微孔碳材料典型样品具有相对较大以及比较规则的微孔, 其比表面积可以达到1260 m2·g-1, 孔体积为0.63 cm3·g-1. 所得微孔碳作为超级电容器电极材料的等效串联电阻为0.46 Ω, 其循环伏安曲线展示出较好的矩形性. 恒流充放电分析结果表明, 当电流密度为1 A·g-1时, 微孔碳电极的比电容为196 F·g-1; 在10 A·g-1的大电流密度下, 比电容仍然达到137 F·g-1. 该电极具有优良的循环稳定性, 1000次循环后比电容保持率达到98%. 这一研究结果表明, 所得微孔碳在超级电容器电极材料方面具有重要的应用前景. 相似文献
6.
7.
8.
Yu Liu Qian Zhang Dong-Sheng Guo Rui-Jie Zhuang Li-Hua Wang 《Thermochimica Acta》2008,470(1-2):108-112
The binding of three nucleobase-modified β-CDs, (i.e., mono(6-ade-6-deoxy)-β-CD 2, mono(6-thy-6-deoxy)-β-CD 3, and mono(6-ura-6-deoxy)-β-CD 4) with four bile salts (deoxycholate, DCA; cholate, CA; glycocholate, GCA; and taurocholate, TCA) were investigated by means of circular dichroism, 2D NMR spectroscopy and calorimetric titration. The results show the binding of host 2 with bile salts is weaker and different from hosts 3 and 4. Enthalpy changes between hosts 2–4 and bile salts are much more favorable than those of native β-CD 1, whereas the entropy changes are unfavorable. 相似文献
9.
离子液体均匀提取-高效液相色谱法测定参附注射液中4种单酯型乌头碱的含量 总被引:1,自引:0,他引:1
摘要 采用离子液体均匀提取-高效液相色谱法测定了参附注射液中苯甲酰乌头碱(BA)、苯甲酰新乌头碱(BM)、苯甲酰次乌头碱(BH)和苯甲酰脱氧乌头碱(BD)的含量,通过优化离子液体的用量,样品溶液的pH值,提取时间和盐浓度等参数,确定最佳提取条件为:pH为中性,盐浓度为5%,采用0.058g的[C6Mim][ BF4]和0.26g的 NH4PF6作为提取剂,提取1min,可有效地将目标物从5mL注射液中提取出来。在此实验条件下测得四种单酯型乌头碱的检测限分别为45.5(BM),19.8(BA),26.3(BH)和12.2(BD)μg L-1,对参附注射液样品进行分析,加样回收率范围在93.74-107.91%,RSD值均小于4.34%。 相似文献
10.
In order to investigate the variational-cumulant expansion (VCE) method, the 2-dimensional Ising model is expanded to the seventh order by adopting the method of enumerating connected diagrams, in whose process, how to determine the variational parameter is analyzed. The internal energy (U), specific heat (C) and spontaneous magnetization (M) are calculated from the first order to the seventh order. The results show that the thermodynamic and magnetic quantities converge to the exact values very quickly and the critical point approaches the exact one order by order. The curve-pairing phenomenon is watched between neighboring order curves at high teinperature region. 相似文献