低阶煤基炭材料研究进展

低阶煤因其储量丰富、富含多环芳烃有机物、含碳量高、成本低等特点,被认为是炭材料的优质前驱体。然而,由于不同低阶煤的灰分、微观结构、界面的差异,导致了煤基炭材料结构、性能难以有效调控的问题。近年来,研究人员提出了低阶煤基炭材料微观结构、表界面调控的有效方法。本文重点总结了低阶煤制备吸附活性炭、电容炭、硬炭、石墨和纳米炭材料的差异化策略,进一步讨论了煤种和工艺对煤基炭材料的微观结构、界面特性和官能团种类等的影响。同时介绍了煤基炭材料在吸附、超级电容器和碱金属电池中的应用。最后,展望了低级煤基炭材料未来研究的方向和挑战。

The relationship between the high-frequency performance of supercapacitors and the type of doped nitrogen in the carbon electrode

Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particularly in terms of their high-frequency response.However,the charge storage and electrolyte ion response mechanisms of different nitrogen dopants at high frequencies are still unclear.In this study,melamine foam carbons with different configurations of surfacedoped N were formed by gradient carbonization,and the effects of the configurations on the high-frequency response behavior of the supercapacitors were analyzed.Using a combination of experiments and first-principle calculations,we found that pyrrolic N,characterized by a higher adsorption energy,increases the charge storage capacity of the electrode at high frequencies.On the other hand,graphitic N,with a lower adsorption energy,increases the speed of ion response.We propose the use of adsorption energy as a practical descriptor for electrode/electrolyte design in high-frequency applications,offering a more universal approach for improving the performance of N-doped carbon materials in supercapacitors.

β-胡萝卜素-15,15’-加氧酶基因rs11646692位点单核苷酸多态性与血液β-胡萝卜素水平的相关性研究

目的分析β-胡萝卜素-15,15’-加氧酶(BCO1)基因rs11646692位点单核苷酸多态性(SNP)与血液β-胡萝卜素水平的关系。方法从浙江省宁波市某区体检人群中筛选研究对象(男性94人,女性96人),连接酶检测法检测rs11646692位点基因型,等度反向HPLC法测定血浆β-胡萝卜素水平。结果 t检验显示rs11646692位点基因型的分布在性别间无统计学差异(P> 0.05),女性血液β-胡萝卜素浓度高于男性(P <0.001)。控制性别因素后,广义线性模型分析结果显示rs11646692基因型(P=0.039)、蔬菜摄入量(P=0.037)、以及二者的交互作用(P=0.005)对β-胡萝卜素水平有影响;在蔬菜摄入量大于150g/d的人群中,rs11646692位点为GG型者的β-胡萝卜素浓度高于CC或CG型者(P分别为0.048和0.003)。结论 BCO1 rs11646692 SNP基因型和蔬菜摄入可共同影响血液β-胡萝卜素水平。