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361.
Giridhar Pulletikurthi Bj?rn B?decker Andriy Borodin Bernd Weidenfeller Frank Endres 《自然科学进展(英文版)》2015,25(6):603-611
The addition of 1-butylpyrrolidine to AlCl_3 results in the formation of an electrolyte that is suited to Al deposition.The feasibility of electrodepositing Al from the synthesized electrolyte was investigated.Several compositions of AlCl_3 and 1-butylpyrrolidine were prepared for this purpose.These mixtures show a different phase behavior at various compositions of AlCl_3 and 1-butylpyrrolidine.IR,Raman and NMR spectroscopy were employed to characterize the synthesized liquids.Among the prepared compositions,1:1.2 mol ratio of 1-butylpyrrolidine:AlCl_3 and the upper phase of 1:1.3 mol ratio of 1-butylpyrrolidine:AlCl_3 were found to be suitable for Al electrodeposition at room temperature(RT).Uniform and thick( mm thick) layers of Al were obtained on copper at RT.Al deposition occured from the cationic species of AlCl_3 xLty(where x r 2,y ? 1–2,and L ? 1-butylpyrrolidine) in this electrolyte.This behavior is contrary to the well investigated classic AlCl_3 based ionic liquids,where the deposition of Al occurs mainly from anionic Al2 Cl 7ions. 相似文献
362.
Self-discharge(SD) of AC/AC(AC ? activated carbon) electrochemical capacitors in aqueous solutions of lithium sulfate(Li2SO4) and lithium sulfate t iodide salts(Li2SO4tKI or Li2SO4tLi I) was investigated at 24 1C and 40 1C after cell potential hold at values from 1 V to 1.6 V.At24 1C,the cells exhibit lower SD in Li2SO4tKI than in Li2SO4,owing to the redox activity of the 2I /I2 system which drives the positive AC electrode to operate in narrow potential range and display lower potential drop than in Li2SO4.At 401 C,the capacitors exhibit comparable and reduced SD both in Li2SO4tLi I and Li2SO4,whatever the holding cell potential.Three-electrode cell experiments demonstrate that,at 40 1C,hydrogen chemisorption is thermodynamically unfavored under negative polarization,while the activity of the 2I /I2 redox system under positive polarization is only slightly reduced.As a consequence,the AC/AC cells in Li2SO4 exhibit a typical electrical double-layer performance at 401 C,whereas they still behave as hybrid ones in Li2SO4tLi I,with twice higher capacitance than in Li2SO4.The(Ui-Ut) vs t1/2plots demonstrate that SD is essentially controlled by diffusion at 401 C,suggesting that it originates from bulkier hydrated ions.Overall,in the investigated temperature range,the AC/AC capacitors in Li2SO4tLi I demonstrate low self-discharge and high capacitance,while being able to operate up to 1.6 V. 相似文献
363.
Hui Song ? Zhibiao Nan 《科学通报(英文版)》2014,59(11):1129-1138
The class of nucleotide-binding site (NBS)- Leucine-rich repeat (LRR) disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Consequently, many NBS-LRR genes have been identified in various plant species. In this study, we identified 617 NBS-encoding genes in the Medicago truncatula genome (Mt3.5v5) and divided them into two groups, regular (490) and non-regular (127) NBS- LRR genes. The regular NBS-LRR genes were character- ized on the bases of structural diversity, chromosomal location, gene duplication, conserved protein motifs, and EST expression profiling. According to N-terminal motifs and LRR motifs, the 490 regular NBS-LRR genes were then classified into 10 types: CC-NBS (4), CC-NBS-LRR (212), TIR-NBS (20), TIR-NBS-LRR (160), TIR-NBS-TIR (1), TIR-NBS-TIR-LRR (2), NBS-TIR (7), NBS-TIR-LRR (1), NBS (10), and NBS-LRR (73). Analysis of the phys- ical location and duplications of the regular NBS-LRR genes revealed that the M. truncatula genome is similar to rice. Interestingly, we found that TIR-type genes are more frequently expressed than non-TIR-type genes in M. trun- catula, whereas the number of non-TIR-type regular NBS- LRR genes was greater than TIR-type genes, suggesting the gene expression was not associated with the total number of NBS-LRR genes. Moreover, we found that the phylogenetic tree supported our division of the regular NBS-LRR genes into two distinct clades (TIR-type and non-TIR-type), but some of the non-TIR-type lineages contain TIR-type genes. These analyses provide a robust database of NBS-LRR genes in M. truncatula that will facilitate the isolation of new resistance genes and breeding strategies to engineer disease resistance in leguminous crop 相似文献
364.
Wenying He ? Chengzhi Zou ? Hongbin Chen 《科学通报(英文版)》2014,59(11):1159-1166
GPS radio occultation data from the Constellation Observing System for Meteorology, Ionosphere, and Climate(COSMIC) mission were used to validate the measurements of the advanced microwave sounding unit-A(AMSU-A) in the lower stratosphere from different satellites. AMSU-A observations from two different calibrations—the pre-launch operational and post-launch simultaneous nadir overpass(SNO) calibrations—were compared to microwave brightness temperatures(Tb)simulated from COSMIC data. Observations from three satellites(NOAA-15,-16, and-18) were used in the comparison. The results showed that AMSU-A Tb measurements from both calibrations and from all three NOAA satellites were underestimated in the lower stratosphere,and that the biases were larger in polar winters, especially over the southern high latitudes. In comparison to operational calibration, the SNO-calibrated AMSU-A data produced much smaller biases relative to the COSMIC data.The improvement due to SNO calibration was quantified by a Ratio index, which measured the bias changes from operational to SNO calibrations relative to the biases between the operational-calibrated AMSU-A data and the COSMIC data. The Ratio values were 70 % for NOAA-15and [80 % for NOAA-18 and-16, indicating that the SNO calibration method significantly reduced AMSU-A biases and effectively improved AMSU-A data quality. 相似文献
365.
中国野生牡丹花粉形态的研究 总被引:4,自引:0,他引:4
通过扫描电镜观察了芍药科(Paeoniaceae)芍药属(Paeonia)牡丹组(Sect.Moutan DC.)9个野生种23个居群的花粉形态.该组花粉多为长球形,少数近球形和超长球形,具三拟孔沟,大小为22.7~46.4 μm×13.6~29.9 μm,外壁纹饰形态多样,可分为穴状、网状、粗网状、条纹-网状、皱波-网状、皱波状.分析结果表明:花粉形态与植物的外部形态特征有一定关系,同一种野生牡丹生长在不同的环境中,其花粉形态也不同.因此,花粉分析对牡丹组种的区分有一定的参考价值,但要合理揭示其系统发育意义,仍需进行更全面深入的研究. 相似文献
366.
我国的小兴安岭自古以来就是东北虎的出没之地,但是近40年来一直没有东北虎的踪迹.值得欣慰的是,自2014年以来,随着东北地区林地的恢复和森林植被范围的扩大,逐渐有一些东北虎个体从俄罗斯来到我国境内.它们来寻找什么?能不能长久地留在我们的森林中呢? 相似文献
367.
为了给中小城市建立低碳交通体系提供理论依据,利用美国联邦公路局(FHWA)微观仿真软件TSIS/CORSIM,并结合广东省清远市中心城区的交通调查,建立了清远中心城区路网交通仿真模型,对以现状交通流量为基础设定的5个情景方案进行了仿真研究.结果表明:随交通流量的增大,路网的交通排放增加,当增大到1.5倍时,车辆每公里的HC,CO,NOx和CO2排放分别上升8%,12%,12%和29%,当交通流量增加(1.5倍)导致交通拥挤时,额外燃油消耗为225 L,额外CO2排放为518 kg,占总排放的16.3%. 相似文献
368.
人们对锂离子电池的容量与寿命提出越来越高的要求.开发具有新型结构和优越性能的聚合物黏结剂,可有效提高电极在循环过程中的机械和电化学稳定性,最终助力实现高性能锂离子电池.本文通过阐述近年国内外围绕硅负极用黏结剂种类、特性及复合体系的研究成果,总结了黏结剂的组成及物化参数对电极电化学性能的影响规律,并展望硅负极黏结剂的发展... 相似文献
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