We present initial results on the temporal evolution of the phase space density (PSD) of the outer radiation belt energetic electrons driven by the superluminous R-X mode waves. We calculate diffusion rates in pitch a...We present initial results on the temporal evolution of the phase space density (PSD) of the outer radiation belt energetic electrons driven by the superluminous R-X mode waves. We calculate diffusion rates in pitch angle and momentum assuming the standard Gaussian distributions in both wave frequency and wave normal angle at the location L=6.5. We solve a 2D momentum-pitch-angle Fokker-Planck equation using those diffusion rates as inputs. Numerical results show that R-X mode can produce significant acceleration of relativistic electrons around geostationary orbit,supporting previous findings that superluminous waves potentially contribute to dramatic variation in the outer radiation belt electron dynamics.展开更多
Hyphenrones R–X(1–7), seven new polyprenylated acylphloroglucinols derivatives, were isolated from the fruits of Hypericum henryi, together with eight know analogues. Compounds 1 and 2 were elucidated to possess com...Hyphenrones R–X(1–7), seven new polyprenylated acylphloroglucinols derivatives, were isolated from the fruits of Hypericum henryi, together with eight know analogues. Compounds 1 and 2 were elucidated to possess complex caged skeleton, while compounds 3–6 shared a common 3,9-epoxy moiety deriving from the normal polyprenylated acylphloroglucinols with a bicyclo[3.3.1]nonane-2,4,9-trione core. The new structures were elucidated on the basis of the interpretation of nuclear magnetic resonance(NMR) data, circular dichroism(CD) comparison, and single-crystal X-ray diffraction. In the bioassay, several compounds exhibited inhibitory activities against human tumor cell lines in vitro.展开更多
Terra SAR-X图像的几何校正和辐射定标对于获取地面目标高精度地理位置信息和辐射特征具有重要意义。采用距离-多普勒间接定位模型和仿射校正模型进行SAR影像几何校正,同时完成地形辐射校正并对辐射定标精度进行验证。距离向和方位向上...Terra SAR-X图像的几何校正和辐射定标对于获取地面目标高精度地理位置信息和辐射特征具有重要意义。采用距离-多普勒间接定位模型和仿射校正模型进行SAR影像几何校正,同时完成地形辐射校正并对辐射定标精度进行验证。距离向和方位向上达到了约0.3 m和0.4 m的几何定位精度;相对辐射定标精度优于0.3 d B,绝对辐射定标精度为0.22 d B,所以该模型能达到方法较高的精度且简单快捷。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.40774078,40925014,40874076and40931053)the Special Fund for Public Welfare Industry(Meteorology)GYHY200806024the Specialized Research Fund for State Key Laboratories of China.
文摘We present initial results on the temporal evolution of the phase space density (PSD) of the outer radiation belt energetic electrons driven by the superluminous R-X mode waves. We calculate diffusion rates in pitch angle and momentum assuming the standard Gaussian distributions in both wave frequency and wave normal angle at the location L=6.5. We solve a 2D momentum-pitch-angle Fokker-Planck equation using those diffusion rates as inputs. Numerical results show that R-X mode can produce significant acceleration of relativistic electrons around geostationary orbit,supporting previous findings that superluminous waves potentially contribute to dramatic variation in the outer radiation belt electron dynamics.
基金supported by the Natural Sciences Foundation of Yunnan Province (2015FA032)Foundation of State Key Laboratory of Phytochemistry and Plant Resources in West China (P2015-ZZ07)+1 种基金the foundation from Youth Innovation Promotion Association CAS to X.W. Yang and G. Xuthe West Light Foundation of the Chinese Academy of Sciences to X.W. Yang
文摘Hyphenrones R–X(1–7), seven new polyprenylated acylphloroglucinols derivatives, were isolated from the fruits of Hypericum henryi, together with eight know analogues. Compounds 1 and 2 were elucidated to possess complex caged skeleton, while compounds 3–6 shared a common 3,9-epoxy moiety deriving from the normal polyprenylated acylphloroglucinols with a bicyclo[3.3.1]nonane-2,4,9-trione core. The new structures were elucidated on the basis of the interpretation of nuclear magnetic resonance(NMR) data, circular dichroism(CD) comparison, and single-crystal X-ray diffraction. In the bioassay, several compounds exhibited inhibitory activities against human tumor cell lines in vitro.
基金Supportedin part by the Natural Science Foundation of Zhejiang Province(Y6090404)supported in part by the Graduate Innovation Seed Project of Hangzhou Normal University
文摘Terra SAR-X图像的几何校正和辐射定标对于获取地面目标高精度地理位置信息和辐射特征具有重要意义。采用距离-多普勒间接定位模型和仿射校正模型进行SAR影像几何校正,同时完成地形辐射校正并对辐射定标精度进行验证。距离向和方位向上达到了约0.3 m和0.4 m的几何定位精度;相对辐射定标精度优于0.3 d B,绝对辐射定标精度为0.22 d B,所以该模型能达到方法较高的精度且简单快捷。
