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111.
Silanized support based SERS substrate is applied to detect chrysoidin in Sprite at 0.01 mg/L and malachite green in fish pond water at 0.0001 mg/L. The SERS method is sensitive, cost-effective and convenient, which has great potential in detection of illegal additives and harmful substances. 相似文献
112.
《化学:亚洲杂志》2018,13(19):2770-2780
Owing to resource abundance, and hence, a reduction in cost, wider global distribution, environmental benignity, and sustainability, sodium‐based, rechargeable batteries are believed to be the most feasible and enthralling energy‐storage devices. Accordingly, they have recently attracted attention from both the scientific and industrial communities. However, to compete with and exceed dominating lithium‐ion technologies, breakthrough research is urgently needed. Among all non‐electrode components of the sodium‐based battery system, the electrolyte is considered to be the most critical element, and its tailored design and formulation is of top priority. The incorporation of a small dose of foreign molecules, called additives, brings vast, salient benefits to the electrolytes. Thus, this review presents progress in electrolyte additives for room‐temperature, sodium‐based, rechargeable batteries, by enlisting sodium‐ion, Na−O2/air, Na−S, and sodium‐intercalated cathode type‐based batteries. 相似文献
113.
Qiuwei Shi Yiren Zhong Min Wu Prof. Hongzhi Wang Prof. Hailiang Wang 《Angewandte Chemie (International ed. in English)》2018,57(29):9069-9072
Developing Na metal anodes that can be deeply cycled with high efficiency for a long time is a prerequisite for rechargeable Na metal batteries to be practically useful despite their notable advantages in theoretical energy density and potential low cost. Their high chemical reactivity with the electrolyte and tendency for dendrite formation are two major issues limiting the reversibility of Na metal electrodes. In this work, we introduce for the first time potassium bis(trifluoromethylsulfonyl)imide (KTFSI) as a bifunctional electrolyte additive to stabilize Na metal electrodes, in which the TFSI? anions decompose into lithium nitride and oxynitrides to render a desirable solid electrolyte interphase layer while the K+ cations preferentially adsorb onto Na protrusions and provide electrostatic shielding to suppress dendritic deposition. Through the cooperation of the cations and anions, we have realized Na metal electrodes that can be deeply cycled at a capacity of 10 mAh cm?2 for hundreds of hours. 相似文献
114.
Single-phase LiCoPO4 nanoparticles were synthesized by solid-state reaction method and subsequent high-energy ball milling. The electrochemical
properties of LiCoPO4/Li batteries were analyzed by ac impedance experiments, cyclic voltammetry (CV), and charge/discharge tests. The structural
and morphological performance of LiCoPO4 nanoparticles was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron
microscope (TEM). The XRD result demonstrated that LiCoPO4 nanoparticles had an orthorhombic olivine-type structure with a space group of Pmnb. Different conductive additives including
acetylene black and carbon black (SP270) were used to fabricate electrodes. The morphologies of the electrodes and different
conductive additives were observed by field emission-scanning electron microscopy (FE-SEM). LiCoPO4/Li battery with acetylene black showed the best electrochemical properties, and exhibited a discharge plateau at around 4.7 V
with an initial discharge capacity of 110 mAh g−1 at a discharge current density of 0.05 mA cm−2 at 25 °C. 相似文献
115.
Guoyi Bai Hailong Wang Huisen Ning Fei He Guofeng Chen 《Reaction Kinetics and Catalysis Letters》2008,94(2):375-383
A continuous process for the dehydrogenation of cyclohexanol to cyclohexanone on copper-based catalysts was described. The
catalysts were characterized by XRD, XPS and TPR, and Cu0 was found to be the active site for the copper-based catalysts studied. The two carrier catalysts were proved to be more
active than the single carrier ones, and the Cr additive, which mainly existed as the CuCr2O4 phase on the catalyst’s surface, was found to have a significant effect on the activity and stability of the Cu-Cr-Mg-Al
catalyst. 相似文献
116.
Here we describe the story behind the link between molecular chirality and macroscopic phenomena, the latter being a probe for the direct assignment of absolute configuration of chiral molecules. First, a brief tour of the history of molecular stereochemistry, starting with the classic experiment reported by Pasteur in 1848 on the separation of enantiomorphous crystals of a salt of tartaric acid, and his conclusion that the molecules of life are chiral of single-handedness. With time, this study raised, inter alia, two fundamental questions: the absolute configuration of chiral molecules and how a molecule of given configuration shapes the enantiomorphous morphology of its crystal. As for the first question, following the beginning of crystal structure determination by X-ray diffraction in 1912, it took almost 40 years before Bijvoet assigned molecular chirality through the esoteric method involving anomalous X-ray scattering. We have been able to address and link both questions through ‘everyday concepts of left and right’ (in the words of Jack Dunitz) by the use of ‘tailor-made’ auxiliaries. By such means, it proved possible to reveal, through morphology, etch patterns, epitaxy and symmetry reduction of both chiral and, paradoxically, centrosymmetric crystals, the basic chiral symmetry of the molecules of life, the α-amino acids and sugars. 相似文献
117.
118.
An additive-free Watts type bath containing micron- and nano-SiC particles (1 μm and 20 nm respectively), as well as ultrafine-WC
particles (200 nm), was used for the production of pure Ni and nickel matrix composite electrocoatings under both direct and
pulse current conditions. Moreover, nickel nanocrystalline deposits were obtained from a Watts type bath containing small
amounts of 2-butyne-1,4-diol, in order to investigate the combined advantages of additives and pulse technique on the properties
of the deposits. The influence of the variable electrolysis parameters, the particle size and the organic additive concentration
on the surface morphology, the structure and properties of the deposits were discussed. It has been proved that the application
of pulse electrodeposition affects drastically the structural characteristics and properties of the deposits and under well-defined
conditions could lead to the preparation of nanostructured materials with improved mechanical properties.
Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 6, pp. 802–811.
The text was submitted by the authors in English. 相似文献
119.
镍氢电池的循环性能与活性物质微结构的研究 总被引:1,自引:0,他引:1
与循环试验大致同步, 用静态(初态和终态)或准动态(增加若干个中间态)的模式对MH/H电池循环性能、电极(包括负极和正极)材料的微结构进行了X射线衍射(XRD)研究, 发现循环性能衰减与正极材料β-Ni(OH)2的点阵参数、平均晶粒尺度、微应变和总的层错几率均随循环周期增加而减小以及负极材料中腐蚀产物A(OH)3和B相出现和增加有一定的对应关系, 发现MH/Ni 电池循环性能的衰减是正极材料和负极材料的结构和微结构随着循环次数的增加发生明显变化, 恶化了正负极材料的电化学性能, 同时消耗和恶化了电解液的综合结果. 为了提高电池的循环性能, 采用不同正极材料的添加剂. 结果表明, CaF2和Lu2O3有明显的效果, 其中CaF2效果最好, 并有广泛的实用性. 相似文献
120.
以合成的两种无灰型含磷/硫化合物为润滑添加剂, 以可生物降解的菜籽油作为基础油, 用四球机研究了体系的抗磨减摩性能, 以X射线光电子能谱(XPS)和X射线吸收精细结构光谱(XANES)对所形成的摩擦膜和热膜进行了表面分析, 并初步探讨了其润滑机理. 摩擦学研究结果表明, 两种含磷/硫化合物作为菜籽油的润滑添加剂时, 具有良好的抗磨减摩性能. XPS和XANES分析结果显示, 摩擦膜和热膜主要由吸附层和反应层组成; 在表面膜中, 磷主要以磷酸盐或焦磷酸盐等形式存在, 而硫主要以硫酸盐的形式存在. 研究结果还表明, 摩擦热在两种不同添加剂的摩擦膜形成过程中发挥着不同的作用. 相似文献