碳排放气体浓度遥感监测研究

结合国际碳排放气体浓度遥感监测最新研究进展,介绍了碳排放监测方法,以及碳排放气体浓度遥感监测技术(包括热红外、太阳波谱、主动遥感监测技术)。并详细介绍了目前已在使用和未来将采用的监测主要碳排放气体的几种星载传感器,并对这些传感器已获取的监测结果进行了详细分析。     

Study on GaN-based light emitting diode with InGaN/GaN/InGaN multi-layer barrier

The current study investigates GaN-based light-emitting diodes (LEDs) with InGaN/GaN/InGaN multi-layer barrier (MLB). Simulation results show that GaN-based LEDs with MLB have better performance than conventional GaN-based LEDs with only one GaN barrier because of the enhancement in hole injection into the quantum well and decrease in electron leakage current.     

手性膦配体的合成及其在不对称催化反应中的应用研究进展

手性膦配体的合成及其在不对称催化反应中的应用一直是不对称有机合成和催 化研究中非常重要的研究领域，大量的单齿、双齿和多齿磷配体被合成出来并成功 地应用于不对称催化研究。综述了近十几年来手性磷配体的研究进展。     

An investigation into power attenuations in deformed polymer optical fibers under high temperature conditions

This study investigates the effects of temperature and the bend radius on the power loss and average plastic energy density (APED) in SH-4001, MH-4001 and GH-4001 polymer optical fibers (POFs) deformed at temperatures ranging from 25 to 80 °C. The results show that the APED index provides a viable means of predicting the power loss in the three POFs. Based on the experimental data, curve-fitted equations are derived to estimate the power losses in the three POFs under given deformation and temperature conditions. The difference between the estimated results and the experimental results is found to be less than 6%. The experimental results also indicate that, of the three POFs considered in the present study, the GH-4001 fiber has a higher glass transition temperature and has the best power loss resistance, particularly under higher temperature deformation conditions.     

鼠脑尾核和海马区微透析液中儿茶酚胺类神经递质的高效液相色谱分析

采用反相液相色谱分离-脉冲安培检测和微透析取样技术,测定了取自鼠脑尾核和海马区微透析液中儿茶酚胺类神经递质的含量。对不同神经活动状态下取得微透析液中肾上腺素含量作了比较,将该法用于测定肾上腺素,灵敏度为25μg/L.     

利用介孔材料制备碳纳米管的形貌、结构和Raman散射研究

以碳氢气体为反应物,利用化学气相沉积方法,在不同的衬底上制备了碳纳米管。研究了不同衬底对碳纳米管生长方式的影响。对碳纳米管的形貌和结构进行了观察研究,在介孔二氧化硅衬底上制备了取向生长的碳纳米管。碳纳米管具有很高的密度和纯度。研究了取向碳纳米管的Raman谱,分析了碳纳米管的Raman共振特性与其微观结构的关系。     

Green-emitting Polyfluorenes Containing Hexylthiophen-dibenzothiophene-S,S-dioxide Unit with Large Two-photon Absorption Cross Section

Green light-emitting polyfluorenes containing 3,7-bis(4-hexylthiophen-2-yl)dibenzo[b,d]thiophene 5,5-dioxide(DHTSO)unit were synthesized.All the resulted polymers show high thermal stability with the decomposition temperatures(T_d)over 420°C and the glass transition temperatures(T_g)over 75°C.The polymers exhibit the enhanced highest occupied molecular orbital(HOMO)energy levels and the depressed lowest unoccupied molecular orbital(LUMO)energy levels with the increase of DHTSO unit in polymers.The photoluminescence(PL)spectra of the polymers show positive solvatochromism in solution with the variation of solution polarities,indicating remarkable intramolecular charge transfer(ICT)effect in the polymers containing DHTSO moiety.The fluorescence quantum yields((37)_(PL))are in the range of 34%-67%for PF-DHTSOs in film.All polymers possess two photon absorption(TPA)properties,and the TPA cross sections(?_2)are enhanced with increasing DHTSO unit in polymers.The highest?_2 is 2392 GM for PF-DHTSO15 in chloroform solution upon 740 nm excitation.The device of PF-DHTSO15 shows green emission with the Commission Internationale de L’.Eclairage(CIE)coordinates of(0.26,0.59),and the maximum luminous efficiency(LE_(max))of 10.8 cd·A~(-1) with the configuration of ITO/PEDOT:PSS/EL/Cs F/Al.These results indicate that introducing DHTSO unit into polyfluorene backbone could be a promising molecular design strategy for TPA and effective green-light emission.     

Neighboring lithium-assisted [1,2]-Wittig rearrangement: practical access to diarylmethanol-based 1,4-diols and optically active BINOL derivatives with axial and sp3-central chirality

A facile and practical methodology for the synthesis of synthetically useful diarylmethanol‐based 1,4‐diols and enantiomerically pure BINOL‐derived diols with axial and sp³‐central chirality has been developed through neighboring lithium‐promoted [1,2]‐Wittig rearrangement. The chirality transfer process shows a broad substrate scope in terms of the aromatic ether substituent, which allows access to a broad of range of chiral 1,1′‐binaphthalene‐2‐α‐arylmethanol‐2′‐ols with excellent enantioselectivities (>99 % enantiomeric excess) and yields (84–96 %). This should be considered as an available and attractive chiral source to design and prepare privileged ligands or catalysts.     

Copper-Catalyzed Chemo- and Enantioselective Radical 1,2-Carbophosphonylation of Styrenes

The copper-catalyzed enantioselective radical difunctionalization of alkenes from readily available alkyl halides and organophosphorus reagents possessing a P−H bond provides an appealing approach for the synthesis of α-chiral alkyl phosphorus compounds. The major challenge arises from the easy generation of a P-centered radical from the P−H-type reagent and its facile addition to the terminal side of alkenes, leading to reverse chemoselectivity. We herein disclose a radical 1,2-carbophosphonylation of styrenes in a highly chemo- and enantioselective manner. The key to the success lies in not only the implementation of dialkyl phosphites with a strong bond dissociation energy to promote the desired chemoselectivity but also the utilization of an anionic chiral N,N,N-ligand to forge the chiral C(sp³)−P bond. The developed Cu/N,N,N-ligand catalyst has enriched our library of single-electron transfer catalysts in the enantioselective radical transformations.