搜索结果: 1-15 共查到“MAS-NMR”相关记录31条 . 查询时间(0.125 秒)
13C CP/MAS NMR光谱法分析烟草果胶的含量和结构
烟草 果胶 NMR光谱 结构分析
2015/6/18
采用CP/MAS 13C NMR光谱法分析烟草果胶的含量和结构。对烟草果胶进行了优化提取后, 再对其13C NMR光谱图C-6吸收峰区域进行了详细研究, 用于计算果胶中半乳糖醛酸(GalA)、甲酯度(DM) 和乙酰度(DA) 的含量, 并就建立的定量方法与经典的色谱法和重量法进行了比较。结果表明, CP/MAS 13C NMR光谱法测定烟草样品中果胶的含量是可靠的, 化学位移和峰面积可用来计算烟草...
27Al和29Si MAS-NMR对Mo/HZSM-5催化剂的研究
Mo/HZSM-5 NMR 脱铝 Al2(MoO4)3 甲烷无氧活化
2009/12/14
27Al和29Si MAS-NMR对Mo/HZSM-5催化剂的研究。
利用二维多量子魔角旋转（2D MQ MAS）技术并结合量子化学计算，研究了铝在MCM-22分子筛骨架上的分布，并对铝的不等价四面体位进行了归属.在27Al 2D 5Q MAS NMR谱中骨架四配位铝的范围内观察到3个信号，证明MCM-22分子筛有3种骨架铝.经计算这3种骨架四配位铝的各向同性化学位移和四极作用常数分别为：δ 50.5、δ 57.3、δ 62.4和1.74、1.68、1.92 MHz...
Effect of Addition Method of Phosphorus on Alumina-supported NiMoP Catalysts —Hydrodesulfurization of 4,6-Dimethyldibenzothiophene and Characterization Using MAS NMR—
Nickel molybdenum catalyst Phosphorus addition Hydrodesulfurization
2009/7/24
A series of Ni-Mo-P/Al2O3 catalysts with phosphorus added by different methods were prepared. The hydrodesulfurization of 4,6-dimethyldibenzothiophene (4,6-DMDBT) was carried out using the catalysts....
以不同交联度的PH敏感丙烯酰胺-丙烯酸P(AmNaAc)及温敏异丙基丙烯酰胺-丙烯酸P(NIPA-Ac)交联共聚水凝胶为实验体系,研究了用二维及固体高分辨NMR技术表征溶胀态下交联高分子材料微观结构的方法,结果表明,高灵敏度的 2D HMQC、NOESY及固体高分辨 MAS NMR技术是研究这类体系微观结构的有力工具。
有机-无机杂化磷酸锆及胺插层化合物的MAS NMR 研究
有机-无机杂化磷酸锆 胺插层化合物 MAS NMR
2008/4/30
英文关键词：zirconium phosphonate-phosphate; amine-intercalated compound; MAS NMR
The layered zirconium [N-(phosphonomethyl)iminodiacetic acid-phosphate]
Zr(HPO4)1.3...
Multinuclear MAS NMR study of structural changes in LaF3 doped borosilicate glasses for optoelectronics
oxyfluoride glass borosilicate glass
2011/5/5
A new type of oxyfluoride glass-ceramics based on the silicate glassy matrix and the nano-phase of LaF3 was developed for generating the up-conversion luminescence processes. In such material, the low...
^1^1^3Cd MAS NMR谱表征纳米CdO， CdS在NaY的β笼内 形成的构型
结构表征 纳米相材料 光敏材料 构型 分子筛 簇 硫化镉 笼状结构 氧化镉 核磁共振谱法 镉113核磁共振谱法
2007/12/19
摘要 通过29^Si,27^Al和^1^1^3CdMASNMR谱，观察到如下结果：(1)在Nayβ笼内形成的CdO和CdS簇，它们的^1^1^3Cd化学位移分别为115.0和100.0这些值接近于体相CdO的化学位移83.5，而远离体相CdS的化学位移583.8，因此它们的构型应归属为体相CdO的立方岩盐构型，而不属于体相CdS的配位数为4的闪锌矿构型。(2)CdO-NaY硫化时，NaY的骨架脱铝...
13C CP/MAS NMR spectra of pectins: a peak-fitting analysis in the C-6 region
13C CP/MAS NMR pectins peak fitting degrees of methylation (DM) degrees of acetylation (DAc)
2014/3/19
13C CP/MAS NMR spectra of pectin samples were measured and interpreted. The influence of methylesterification and O-acetylation on chemical shifts of pectin carbons was studied using model pectate, pe...
13C CP/MAS NMR spectra of pectins: a peak-fitting analysis in the C-6 region
13C CP/MAS NMR pectins peak fitting degrees of methylation (DM) degrees of acetylation (DAc)
2014/3/19
13C CP/MAS NMR spectra of pectin samples were measured and interpreted. The influence of methylesterification and O-acetylation on chemical shifts of pectin carbons was studied using model pectate, pe...
13C CP/MAS NMR spectra of pectins: a peak-fitting analysis in the C-6 region
13C CP/MAS NMR pectins peak fitting degrees of methylation (DM) degrees of acetylation (DAc)
2014/3/19
13C CP/MAS NMR spectra of pectin samples were measured and interpreted. The influence of methylesterification and O-acetylation on chemical shifts of pectin carbons was studied using model pectate, pe...
Solid-state 29Si MAS NMR studies of illite and illite-smectite from shale
Solid-state 29Si MAS NMR studies illite illite-smectite shale
2012/4/1
A new method to extract quantitative information from poorly resolved Si magic-angle spinning
(MAS) nuclear magnetic resonance (NMR) spectra of natural mixed-layer illite-smectite (I-S) clays29Si
i...
Local Ca-Mg distribution of Mg-rich pyrope-grossular garnets synthesized at different temperatures revealed by 29Si MAS NMR spectroscopy
Local Ca-Mg distribution Mg-rich pyrope-grossular garnets synthesized different temperatures revealed 29Si MAS NMR spectroscopy
2012/4/1
Pyrope-grossular solid solutions, (Mg,Ca) Al Si O , of composition Py Gr and Py Gr were3 2 3 12 85 15 75 25
synthesized at 1000, 1200, and 1400 ?C and 30 kbars in a piston-cylinder device. The synt...
Three- and five-quantum 17O MAS NMR of forsterite Mg2SiO4
Three- and five-quantum 17O MAS NMR forsterite Mg2SiO4
2012/3/31
17Three- and five-quantum O MAS NMR experiments are used to resolve fully the three crystallo-
graphically distinct oxygen species in forsterite (Mg
SiO ). The chemical shift and quadrupolar pa-2 4...
23Na, 29Si, and 71Ga MAS-NMR spectroscopy of synthetic gallian-fluor-amphiboles
synthetic gallian-fluor-amphiboles magic-angle-spinning nuclear magnetic resonance
2012/3/31
A magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopic study was done
on the series of synthetic gallian-fluor amphiboles to identify the extent of Ga and Si ordering in the
Si MA...