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Electrochemical Reduction of Nitrobenzene in Ionic Liquid BMImac

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Chemical Research in Chinese Universities 2014年第2期30卷 293-296页

作者： ZHANG Yinxu maO Xinbiao REN shuying ma Chunan State Key Laboratory of Green Chemistry Synthesis Technology College of Chemical Engineering and Materials ScienceZhejiang University of Technology Hangzhou 310032 P.R.China

Ionic liquid,1-butyl-3-methylimidazolium acetate（BMImac）,was used in the electrochemical reduction of *** electro-reduction of nitrobenzene on platinum electrode was studied by cyclic voltammetry（CV）,in situ Fourier transform infrared（FTIR） spectroscopy and constant-potential *** experimental results show that electrochemical reduction process of nitrobenzene was controlled by diffusion,the main reduction product was azobenzen at-1.45 V,and the influences of scan rate and temperature on the electrochemical behaviors were obviously.A reduction mechanism of nitrobenzene in an ionic liquid was a probable ‘nitrobenzene→nitrosobenzene→azobenzene→aniline＇ main reductive reaction route.

关键词： Nitrobenzene BMImac Electro-reduction In situ Fourier transform infrared spectroscopy

Prediction of SYM-H index by NARX neural network from IMF and solar wind data

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Science China(Technological Sciences) 2009年第10期52卷 2877-2885页

作者： CAI Lei ma shuying CAI HongTao ZHOU YunLiang LIU RuoSi Department of Space Physics College of Electronic InformationWuhan UniversityWuhan 430079China

SYM-H is one of the important indices for space weather. It indicates the intensity of magnetic storm, similarly to Dst index but with much higher time-resolution. In this paper an artificial neural network (ANN) of Nonlinear Auto Regressive with eXogenous inputs (NARX) has been developed to predict SYM-H index from solar wind and IMF data. In comparison with usual BP and Elman network, the new NRAX model shows much better prediction capability. For 15 testing great storms including 5 super-storms of Min. SYM-H march 2001 with ***-H of -434 nT; while for the two super-storms with Min. SYM-H ranging from -300 nT to -400 nT, the correlations reach as high as 0.93 and 0.96 respectively. The remarkable improvement of the model performance can be attributed to such a key feedback from the network output of SYM-H with a suitable length (about 120 min) to the input, which implies that some information on the quasi real-time ring currents with a proper length of history does its work in the prediction. It tells us that, in addition to the direct driving by solar wind and IMF, the own status of the ring current plays an important role in its evolution especially for recovery phase and must properly be considered in storm-time SYM-H prediction by ANN. The neural network model of NARX developed in this paper provides an effective way to achieve it.

关键词： magnetic storm SYM-H index space weather prediction artificial neural network

Abnormal distribution of ionospheric electron density during November 2004 super-storm by 3D CT reconstructions from IGS and LEO/GPS observations

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Science China(Technological Sciences) 2012年第5期55卷 1230-1239页

作者： XIAO Rui XU JiSheng ma shuying XIONG Chao Luehr H. College of Electronic Information Wuhan UniversityWuhan 430079China Germany Research Center for Geoscience Telegrafenberg14473 PotsdamGermany

Using time-dependent 3D tomography method, the electron density distributions in the low-latitude ionosphere during November 2004 super-storm are reconstructed from GPS observations of joint ground-based IGS network and onboard CHAMP/GRACE satellites. The reconstructed electron densities are validated by satellite in situ measurements of CHAMP and GRACE satellites. It is indicated by computer tomography （CT） reconstructions that the long-lived positive storm phase during the first main phase of the storm （November 8） is mainly attributed to enhancement of electron density in the upper F region above the F2 peak. It is found by the CT imaging that the top-hat-like F2-3 double layers occurred in the equatorial ionization anomaly region during the main phase of the storm （at forenoon of November 8）. The structures of column-like enhanced electron density are found at the time near the minimum of Dst and in the longitudinal sector about 157°E, which extend from the topside ionosphere toward plasmasphere, reaching at least about 2000 km as high. Their footprints stand on the two peaks of the EIA.

关键词： ionosphere electron density abnormal distribution tomogpaphy super-storm

Field-aligned current distribution and response to interplanetary conditions during a superstorm——CHAMP observation

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Chinese Science Bulletin 2007年第2期52卷 248-258页

作者： WANG Hui ma shuying Hermann LUEHR ZHOU YunLiang DANG Ge Institute of Ionosphere and magnetosphere LOGEG CNME College of Electronic Information Wuhan University Wuhan 430079 China GeoForschungsZentrum Potsdam 14473 Germany

With geomagnetic measurements on board of CHAMP satellite, the characteristics of global large-scale field-aligned currents (FACs) in the topside ionosphere are investigated along with their responses to interplanetary conditions for the superstorm of November, 2003. It is found that (1) The storm-time FAC densities enhanced greatly in comparison with quiet period and the enhancements show hemispheric asymmetry of both summer-winter and sunlit-dark. (2) For the first time, it is revealed that the lati-tude-integrated FAC density is controlled mainly by solar wind dynamic pressure rather than IMF. (3) FACs expanded equatorward dramatically, with the lowest latitude being 45° MLat or more; on the day-side this expansion was controlled directly by IMF Bz, showing an interaction time scale of about 25 min in the solar wind-magnetosphere-ionosphere coupling system, and a nonlinear saturation of the equatorward expansion when IMF Bz main phase, the nightside FAC latitude coverage extended to 25° or wider, appearing multi-sheet current structure with more than 10 sheets.

关键词：地磁场地球空间耦合机制电离层

Numerical Simulation of Ionization Enhancement in the Topside Ionosphere of Cusp Foot-Point Region Caused by Low Energy Particle Precipitation

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Wuhan University Journal of Natural Sciences 2008年第2期13卷 185-190页

作者： CAI Hongtao ma shuying G Kirchengast School of Electronic Information/Key Laboratory ofGeospace Environment and Geodesy of Ministry of Education Wuhan University Wuhan 430072 China Institute for Geophysics Astrophysics and MeteorologyUniversity of Graz Graz A-8010 Austria

The Graz Ionospheric Flux Tube Simulations （GIFTS） has been improved. The improved GIFTS model was used to numerically investigate the energy particle precipitation on the distribution of electron density in the ionospheric cusp foot-point region under conditions of large plasma convection during magnetic storm. After including the effects of low energy incident particles, the ionospheric electron densities increase remarkably above altitude of -250 km, showing a peak at about 350 km. The percent enhancements of electron densities increase gradually with altitude, exceed- ing 60% near the upper boundary of the calculation. The calculated ionospheric F2-peak was remarkably enhanced and lifted up by the incident low energy electrons.

关键词： magnetic storms particle precipitation cusp ionization enhancement ionospheric physical model numerical simulation

Cluster observations of high-altitude cusp during multiple fast-turning IMF

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Chinese Science Bulletin 2010年第22期55卷 1178-1185页

作者： CAI HongTao ma shuying DUNLOP M W BOGDANOVA Y DAVIES J A PITOUT F School of Electronic Information Wuhan University Wuhan 430079 China Key Lab of Geospace Environment and Geodesy CNEM Wuhan 430079 China SSTD Rutherford Appleton Laboratory Chilton OX11 OQX UK Department of Physics La Trobe University Melbourne Victoria 3086 Australia max-Planck-lnstitut fiir Extraterrestrische Physik Garching D-37191 Germany

Using coordinated observations from the Cluster,DMSP and ESR radar,high-altitude cusp was investigated for a time period characterized by four fast reversals of the IMF *** February 12,2003,Cluster was flying sunward at duskside over the Northern Hemisphere,across the high-altitude northern cusp *** the two crossings are during steady northward IMF interval,whereas ion fluxes detected during the time period are quite *** cusp in the first crossing is a "typical" northward-IMF one,with short-lived ion injections of evident "reversed" dispersion *** the second crossing,however,the cusp appears to be a region reminiscent of the Stagnant Exterior Cusp (SEC).In addition,evident upward-flowing O+ ion bursts,possibly original from polar ionosphere,are also detected during the second cusp crossing,together with enhancement of trapped magnetospheric-like electron *** suggest that the SEC-like cusp is likely on newly closed field lines,which were first reconnected (being opened) at low latitudes and later reconnected again (being closed) poleward of the northern cusp.

关键词：国际货币基金组织高海拔群集观测十字路口离子检测低纬度地区气象卫星

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Side chains and backbone structures influence on 4,7-dithien-2-yl-2,1,3-benzothiadiazole （DTBT）-based Iow-bandgap conjugated copolymers for organic photovoltaics

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Frontiers of Optoelectronics 2013年第4期6卷 418-428页

作者： Debin NI Dong YANG shuying ma Guoli TU Jian ZHANG Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian National Laboratory of Clean Energy Dalian 116023 China

Five 4,7-dithien-2-yl-2,1,3-benzothiadiazole （DTBT）-based conjugated copolymers with controlled molecular weight were synthesized to explore their optical, energy level and photovoltaic properties. By tuning the positions of hexyl side chains on DTBT unit, the DTBT- fluorene copolymers exhibited very different aggregation properties, leading to 60 nm bathochromic shift in their absorptions and the corresponding power conversion efficiencies （PCEs） value of photovoltaic cells varied from 0.38%, 0.69% to 2.47%. Different copolymerization units, fluorene, earbazole and phenothiazine were also investigated. The polymer based on phenothiazine exhib- ited lower PCE value due to much lower molecular weight owing to its poor solubility, although phenothiazine units were expected to be a better electron donor. Compared with the fluorene-based polymer, the carbazole-DTBT copolymer showed higher short circuit current density （Jsc） and PCE value due to its better intermolecular stacking,

关键词： 4,7-dithien-2-yl-2,1,3-benzothiadiazole(DTBT) conjugated polymers low-bandgap organicphotovoltaics

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板栗树红蜘蛛虫害无人机高光谱遥感监测研究

农业机械学报 2021年第4期52卷 171-180页

作者：马书英郭增长王双亭张凯河南理工大学测绘与国土信息工程学院焦作454003 河南工业职业技术学院城市建设学院南阳473009 河南测绘职业学院郑州451464

为了快速、高效、无损监测板栗树的红蜘蛛病虫害,以实地采集的板栗树局部感染明显叶片、感染轻重不均匀叶片、恢复中的感染叶片及不同感染程度叶片为研究对象,利用UHD185型高光谱相机和数码相机获取各种叶片的高光谱图像和RGB图像,以RG... 详细信息

为了快速、高效、无损监测板栗树的红蜘蛛病虫害,以实地采集的板栗树局部感染明显叶片、感染轻重不均匀叶片、恢复中的感染叶片及不同感染程度叶片为研究对象,利用UHD185型高光谱相机和数码相机获取各种叶片的高光谱图像和RGB图像,以RGB图像为参考,选择各种叶片的感兴趣区,在高光谱图像上提取感兴趣区的光谱曲线,通过微分运算提取光谱曲线的绿峰、红谷、低位、红边、高位、高肩6种光谱特征及特征波长,利用大量实测数据分析板栗树叶各个光谱特征及特征波长随红蜘蛛病虫害危害程度的叶片级变化规律,得到识别红蜘蛛病虫害最佳的光谱特征。利用无人机(Unmanned aerial vehicle,UAV)搭载UHD185型相机,获取了实验区高光谱影像。结果表明,监测板栗树红蜘蛛病虫害危害程度的最佳光谱特征为红边和低位,其与红蜘蛛病虫害的决定系数均超过0.6,当发生轻度红蜘蛛病虫害时,红边波长和低位波长出现"蓝移",说明无人机高光谱遥感系统具有早期发现红蜘蛛病虫害的能力,可为板栗树红蜘蛛病虫害的及时治理提供科学依据。

关键词：板栗树红蜘蛛虫害光谱特征无人机高光谱遥感

Numerical study of the auroral particle transport in the polar upper atmosphere

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Science China(Technological Sciences) 2008年第10期51卷 1759-1771页

作者： CAI HongTao1,2, ma shuying1,2 & PU ZuYin3 1 School of Electronic Information, Wuhan University, Wuhan 430079, China 2 Key Laboratory of Geospace Environment and Geodesy, Ministry of Education of PRC, Wuhan 430079, China 3 School of Earth and Space Sciences, Peking University, Beijing 100871, China School of Electronic Information Wuhan University Wuhan China Key Laboratory of Geospace Environment and Geodesy Ministry of Education of PRC Wuhan China School of Earth and Space Sciences Peking University Beijing China

Starting from the Boltzmann equation and with some reasonable assumptions, a one-dimensional transport equation of charged energetic particles is derived by taking account of major interactions with neutral species in the upper atmosphere, including the processes of elastic scattering, the excitation, the ionization and the secondary electron production. The transport equation is numerically solved, for a simplified atmosphere consisting only of nitrogen molecules (N2), to obtain the variations of incident electron fluxes as a function of altitude, energy and pitch angle. The model results can describe fairly the transport characteristics of pre-cipitating auroral electron spectra in the polar upper atmosphere; meanwhile the N2 ionization rates calculated from the modeled differential flux spectra also exhibit good agreements with existing empirical models in terms of several key parameters. Taking the energy flux spectra of precipitating electrons observed by FAST satellite flying over EISCAT site on may 15, 1997 as model inputs, the model-calculated ionization rate profile of neutral atmosphere consists reasonably with that recon-structed from electron density measurements by the radar.

关键词： aurora particle precipitation polar upper atmosphere electron transport equation numerical simulation