The effect of the azimuthal angle φ of the wave vector k on the propagation characteristics of the superluminous L-O mode waves （together with a case of the R-X mode） during different geomagnetic activities using a...The effect of the azimuthal angle φ of the wave vector k on the propagation characteristics of the superluminous L-O mode waves （together with a case of the R-X mode） during different geomagnetic activities using a three-dimensional （3D） ray-tracing method is investigated. This work is primarily an extension of our previous two-dimensional study in which the wave azimuthal angle was not considered. We present numerical simulations for this mode which is generated in the source cavity along a 70° night geomagnetic field line at the specific altitude of 1.5RE （where RE is the Earth＇s radius）. It is found that, as in the two-dimensional case, the trajectory of L-O mode starting in the source meridian plane （or the wave azimuthal angle φ = 180°） can reach the lowest latitude; whereas it basically stays at relatively higher latitudes starting off the source meridian plane （or φ=180°）. The results reveal that under appropriate conditions, the superluminous L-O mode waves may exist in the radiation belts of the Earth, but this remains to be supplemented by observational data.展开更多
本研究采用AB-8大孔吸附树脂、半制备高效液相色谱对金露梅枝叶中槲皮素-7-O-β-D-葡糖苷酸提取分离,并通过13 C NMR鉴定其化学结构,最后采用以4-硝基酚-α-D-吡喃葡萄糖苷(pNPG)为底物的酶抑制剂筛选模型检测其对α-葡萄糖苷酶的抑制...本研究采用AB-8大孔吸附树脂、半制备高效液相色谱对金露梅枝叶中槲皮素-7-O-β-D-葡糖苷酸提取分离,并通过13 C NMR鉴定其化学结构,最后采用以4-硝基酚-α-D-吡喃葡萄糖苷(pNPG)为底物的酶抑制剂筛选模型检测其对α-葡萄糖苷酶的抑制活性和类型。结果显示:槲皮素-7-O-β-D-葡糖苷酸分布在20%乙醇大孔吸附树脂(AB-8)洗脱液中,采用半制备高效液相色谱和高效液相色谱分离纯化得槲皮素-7-O-β-D-葡糖苷酸2481.8 mg,纯度为97.95%。活性检测结果表明,槲皮素-7-O-β-D-葡糖苷酸对α-葡萄糖苷酶的最大抑制率为94.67%,IC 50为0.259 mmol/L,抑制率显著高于阳性对照药物阿卡波糖,且抑制剂类型为竞争性抑制。展开更多
基金National Natural Science Foundation of China(Nos.40774078,40774077)the Chinese Academy of Sciences(No.KZCX3-SW-144)
文摘The effect of the azimuthal angle φ of the wave vector k on the propagation characteristics of the superluminous L-O mode waves （together with a case of the R-X mode） during different geomagnetic activities using a three-dimensional （3D） ray-tracing method is investigated. This work is primarily an extension of our previous two-dimensional study in which the wave azimuthal angle was not considered. We present numerical simulations for this mode which is generated in the source cavity along a 70° night geomagnetic field line at the specific altitude of 1.5RE （where RE is the Earth＇s radius）. It is found that, as in the two-dimensional case, the trajectory of L-O mode starting in the source meridian plane （or the wave azimuthal angle φ = 180°） can reach the lowest latitude; whereas it basically stays at relatively higher latitudes starting off the source meridian plane （or φ=180°）. The results reveal that under appropriate conditions, the superluminous L-O mode waves may exist in the radiation belts of the Earth, but this remains to be supplemented by observational data.
