制备了依托度酸和哌嗪的有机盐,并得到了其晶体结构。结构解析结果表明,依托度酸羧基上的氢转移到哌嗪的氮原子上,N H O氢键是维持结构稳定的主要分子间相互作用。与原药相比,新合成的盐的本征溶出速率和平衡溶解度分别提高了2.1倍和4....制备了依托度酸和哌嗪的有机盐,并得到了其晶体结构。结构解析结果表明,依托度酸羧基上的氢转移到哌嗪的氮原子上,N H O氢键是维持结构稳定的主要分子间相互作用。与原药相比,新合成的盐的本征溶出速率和平衡溶解度分别提高了2.1倍和4.8倍。此外,新合成的盐具有良好的水合稳定性,在25℃,相对湿度95%的条件下暴露28 d未发生相变。作为依托度酸的第一个有机盐,该盐是依托度酸有前景的固体存在形式。展开更多
基于人工触发闪电T179的10次回击过程,分析了雷电流作用下2个独立地网的相互作用及转移地电位特征,并通过冲击低压电源浪涌保护器(SPD),计算和评估了转移地电位冲击SPD的能量。结果发现,地网隔离40 m距离产生的转移电位(T G P)电压峰值...基于人工触发闪电T179的10次回击过程,分析了雷电流作用下2个独立地网的相互作用及转移地电位特征,并通过冲击低压电源浪涌保护器(SPD),计算和评估了转移地电位冲击SPD的能量。结果发现,地网隔离40 m距离产生的转移电位(T G P)电压峰值比较大,平均值可达–10.9 kV。T G P电压峰值与触发闪电电流峰值之间呈现非常好的正相关性,拟合优度R2达到0.97。冲击SPD的能量比较小,10次回击平均值为1.5 J,电子设备加装SPD浪涌保护器是相对安全。展开更多
In recent years, locating total lightning at the VLF/LF band has become one of the most important directions in lightning detection. The Low-frequency E-field Detection Array(LFEDA) consisting of nine fast antennas wa...In recent years, locating total lightning at the VLF/LF band has become one of the most important directions in lightning detection. The Low-frequency E-field Detection Array(LFEDA) consisting of nine fast antennas was developed by the Chinese Academy of Meteorological Sciences in Guangzhou between 2014 and 2015. This paper documents the composition of the LFEDA and a lightning-locating algorithm that applies to the low-frequency electric field radiated by lightning pulse discharge events(LPDEs). Theoretical simulation and objective assessment of the accuracy and detection efficiency of LFEDA have been done using Monte Carlo simulation and artificial triggered lightning experiment, respectively. The former results show that having a station in the network with a comparatively long baseline improves both the horizontal location accuracy in the direction perpendicular to the baseline and the vertical location accuracy along the baseline. The latter results show that detection efficiencies for triggered lightning flashes and return strokes are 100% and 95%, respectively. The average planar location error for return strokes of triggered lightning flashes is 102 m. By locating LPDEs in thunderstorms, we find that LPDEs are consistent with convective regions as indicated by strong reflectivity columns, and present a reasonable distribution in the vertical direction.In addition, the LFEDA can reveal an image of lightning development through mapping the channels of lightning. Based on three-dimensional locations, the vertical propagation speed of the preliminary breakdown and the changing trend of the leader's speed in an intra-cloud and a cloud-to-ground flash are investigated. The research results show that the LFEDA has the capability for three-dimensional location of lightning, which provides a new technique for researching lightning development characteristics and thunderstorm electricity.展开更多
文摘制备了依托度酸和哌嗪的有机盐,并得到了其晶体结构。结构解析结果表明,依托度酸羧基上的氢转移到哌嗪的氮原子上,N H O氢键是维持结构稳定的主要分子间相互作用。与原药相比,新合成的盐的本征溶出速率和平衡溶解度分别提高了2.1倍和4.8倍。此外,新合成的盐具有良好的水合稳定性,在25℃,相对湿度95%的条件下暴露28 d未发生相变。作为依托度酸的第一个有机盐,该盐是依托度酸有前景的固体存在形式。
文摘基于人工触发闪电T179的10次回击过程,分析了雷电流作用下2个独立地网的相互作用及转移地电位特征,并通过冲击低压电源浪涌保护器(SPD),计算和评估了转移地电位冲击SPD的能量。结果发现,地网隔离40 m距离产生的转移电位(T G P)电压峰值比较大,平均值可达–10.9 kV。T G P电压峰值与触发闪电电流峰值之间呈现非常好的正相关性,拟合优度R2达到0.97。冲击SPD的能量比较小,10次回击平均值为1.5 J,电子设备加装SPD浪涌保护器是相对安全。
基金supported by the National Natural Science Foundation of China(Grant Nos.41675005,91537290&41275008)the Basic Research Fund of Chinese Academy of Meteorological Sciences(Grant Nos.2016Z002&2015Z006)
文摘In recent years, locating total lightning at the VLF/LF band has become one of the most important directions in lightning detection. The Low-frequency E-field Detection Array(LFEDA) consisting of nine fast antennas was developed by the Chinese Academy of Meteorological Sciences in Guangzhou between 2014 and 2015. This paper documents the composition of the LFEDA and a lightning-locating algorithm that applies to the low-frequency electric field radiated by lightning pulse discharge events(LPDEs). Theoretical simulation and objective assessment of the accuracy and detection efficiency of LFEDA have been done using Monte Carlo simulation and artificial triggered lightning experiment, respectively. The former results show that having a station in the network with a comparatively long baseline improves both the horizontal location accuracy in the direction perpendicular to the baseline and the vertical location accuracy along the baseline. The latter results show that detection efficiencies for triggered lightning flashes and return strokes are 100% and 95%, respectively. The average planar location error for return strokes of triggered lightning flashes is 102 m. By locating LPDEs in thunderstorms, we find that LPDEs are consistent with convective regions as indicated by strong reflectivity columns, and present a reasonable distribution in the vertical direction.In addition, the LFEDA can reveal an image of lightning development through mapping the channels of lightning. Based on three-dimensional locations, the vertical propagation speed of the preliminary breakdown and the changing trend of the leader's speed in an intra-cloud and a cloud-to-ground flash are investigated. The research results show that the LFEDA has the capability for three-dimensional location of lightning, which provides a new technique for researching lightning development characteristics and thunderstorm electricity.
