会员主页

全部

• 2018-12-17 04:50发布了问答

  荧光光谱的荧光光谱

  　

  333人看过

• 2018-12-09 09:09发布了问答

  请求达人帮忙做点翻译~~2

  关于化学的文章，有些地方是下标什么的，可能翻译有点麻烦。 Mn3O4 powder was soaked with a LiNO3 solution to get LiMn204． After dryness， the powder was sintered at different temperatures for 24h in air． The X—ray diffraction was carried ... 关于化学的文章，有些地方是下标什么的，可能翻译有点麻烦。 Mn3O4 powder was soaked with a LiNO3 solution to get LiMn204． After dryness， the powder was sintered at different temperatures for 24h in air． The X—ray diffraction was carried out with a Rigaku 12 kW rotary X—ray diffractometer with Cu Ka radiation and a graphite monochromator． Thepowder sample was examined with 2θ varying from10℃ to 75℃．The X—ray diffraction data for the samples sintered at different temperatures showed lines that could be indexed based on the spinel structure. The Raman spectra were excited from the samples held at room temperature，at an excitation wavelength of 517．4 nm and with a Nd—YAG laser operated at 1064 cm 1and 10 mW ． The spectra were recorded on a Renishaw Raman spectrometer with the sample mounted in a backscattering(180°) geometry and at a resolution of 4 cm -1． Results and Discussion Although all the diffraction lines can be fitted with a spinel structure very well，we cannot unambiguously distinguish the layered α一NaFeO2 structure(space group R3m )from the spinel structure(space group Fd3m ) only based on those X—ray diffraction data． Raman spectroscopy must be employed to identify the real structure of the materials． Ammundsen et al. have calculated the Raman—active modes for spinel structure based on factor group analysis，showing that there should be five bands for the spinel structure． Fig.2 shows the Raman spectra of LiMn204 sintered at 500 and 600 ℃． There is a significant difference between the spectra from the samples sintered at these two temperatures，i.e.，there are five Raman peaks for the sample sintered at 500 ℃ and only two peaks for the sample sintered at 600 ℃ ．Five calculationpredicted Raman—active modes for LiMn204 are one mode of Alg symmetry，one mode of Eg symmetry，and three modes of T2g symmetry .Accordingly， LiMn204 sample sintered at 600 ℃ seem s not to be crystallized in the spinel structure，while LiMn204 sample sintered below 500 ℃ is crystallized in the spinel structure．Usually，the low—temperature(LT) phase of LiCoO2 exhibits the spinel stucture，while the high—temperature(HT ) phase of it exhibits the α一NaFeO2 structure． According to our Raman data，the LT phase of the LiMn204 powder exhibits the spinel structure， which displays the same tendency as LiCo02 materia1． 展开

  464人看过

• 2018-11-22 18:06发布了问答

  原子吸收光谱的原子化方式有哪些？各有何特点

  　

  325人看过

• 2018-03-15 08:58发布了问答

  二氧化碳分子的红外光谱有2个吸收谱带，分别对应分子的什么运动

  　

  825人看过

• 2018-03-02 04:16发布了问答

  紫外光谱的电子跃迁

  　

  471人看过

• 2017-12-25 20:31发布了问答

  手持光谱仪可以打铂金吗

  手持光谱仪可以打铂金吗

  292人看过

• 2017-10-03 21:34发布了问答

  icp-oes能测出络合的金属离子吗

  　

  533人看过

• 2017-06-19 16:49发布了问答

  仪器分析中激发源和光源是同一个概念吗

  仪器分析中激发源和光源是同一个概念吗... 仪器分析中激发源和光源是同一个概念吗 展开

  405人看过

• 2017-05-11 22:31发布了问答

  荧光光谱测定和圆二色谱测定，溶液配制的浓度有什么要求

  　

  876人看过

• 2017-03-31 10:22发布了问答

  拉曼光谱仪中为什么激发波长越长，输出功率越大

  　

  320人看过

• 2017-03-21 21:33发布了问答

  怎么判断简正振动是有拉曼活性还是红外活性

  　

  953人看过

• 2016-11-24 01:04发布了问答

  色散型红外光谱仪的色散元件材料是什么

  　

  274人看过

• 2016-09-04 11:31发布了问答

  icp-oes电感耦合等离子体发射光谱仪哪家好

  　

  539人看过

• 2016-08-29 15:24发布了问答

  试述血细胞形态学所观察的内容

  　

  376人看过

• 2013-01-26 07:49发布了问答

  谁有苯并咪唑的红外光谱图及特征峰解析啊？

  麻烦有图的朋友发张图，有特征峰解析的发数据，谢谢啦！

  286人看过