排序方式: 共有50条查询结果,搜索用时 31 毫秒
1.
四氢呋喃(THF)-Na2O-SiO2-Al2O3-H2O体系水热合成的THF-FER沸石,经酸交 换-焙烧脱THF(Ⅰ)或焙烧脱THF-酸交换(Ⅱ)的不同方式处理,均可制得低钠H- FER沸石。经XRD,^27Al与^29Si MAS NMR,低温氮吸附等表征证明,通过1273K高温 的热处理和1073K饱和水蒸气下的水热处理,H-FER沸石骨架保持高度稳定。在高温 水蒸气作用下,Si(2Al)容易从骨架上脱离,而Si(1Al)则保持相对稳定,以(Ⅱ )方法处理,制备的H-FER沸石在水热条件下易产生较多的硅差劲基缺陷。经高温 热和水热处理后,H-FER沸石孔道结构基本保持完美、开放。 相似文献
2.
用^13C HPDEC MAS NMR与热分析方法表征了在四氢呋喃(THF)-Na2O-SiO2- Al2O3-H2O体系中水热合成的高硅Na-THF-FER沸石、酸交换后的H-THF-FER沸石以及 吸附于Na-FER和H-FER沸石中的THF。结果证明,模板剂分子THF位于Na-THF-FER沸 石骨架的FER笼内,平衡骨架阳离子Na^+主要存在于十元环孔道;而吸附子FER沸石 中的THF仅处于十元环孔道中,合成样品中THF的化学位移与液态THF相比,向低场 移动,谱线明显变宽,表明THF分子与FER笼之间存在很强的相互作用。 相似文献
3.
Crystal and Molecular Structure of Quinide 总被引:1,自引:0,他引:1
CrystalandMolecularStructureofQuinideWANGGang-Li;ZHAOShu-Jie;CHENDe-Chang(NationalInstitutefortheControlofPharmaceuticalandBi... 相似文献
4.
Marko Stojkovic Israel Joel Koenka Wolfgang Thormann Peter C. Hauser 《Electrophoresis》2014,35(4):482-486
A CE system featuring an array of 16 contactless conductivity detectors was constructed. The detectors were arranged along 70 cm length of a capillary with 100 cm total length and allow the monitoring of separation processes. As the detectors cannot be accommodated on a conventional commercial instrument, a purpose built set‐up employing a sequential injection manifold had to be employed for automation of the fluid handling. Conductivity measurements can be considered universal for electrophoresis and thus any changes in ionic composition can be monitored. The progress of the separation of Na+ and K+ is demonstrated. The potential of the system to the study of processes in CZE is shown in two examples. The first demonstrates the differences in the developments of peaks originating from a sample plug with a purely aqueous background to that of a plug containing the analyte ions in the buffer. The second example visualizes the opposite migration of cations and anions from a sample plug that had been placed in the middle of the capillary. 相似文献
5.
Carlos Javier Villagomez Tomaso Zambelli Sébastien Gauthier André Gourdon Sladjana Stojkovic Christian Joachim 《Surface science》2009,603(10-12):1526-1532
An isomer of the methylterrylene molecule was adsorbed both on Cu(111) and on a NaCl bilayer deposited on Cu(111) and imaged by ultra high vacuum scanning tunneling microscopy at low temperature (5 K). On the bare metal surface, the STM images do not reveal any intramolecular resolution and do not depend on the applied tunnel bias. On the contrary, the images acquired at specific bias voltages for the molecule on the salt layer show a striking similarity with the spatial distribution of the electronic probability density in the highest occupied molecular orbital (HOMO) and in the lowest unoccupied molecular orbital (LUMO) of free methylterrylene. They are well reproduced by elastic scattering quantum chemistry calculations. These data provide a direct view of the hyperconjugative interaction between the methyl group and the frontier orbitals of terrylene. 相似文献
6.
Stojkovic D 《Physical review letters》2005,94(1):011603
In models with extra dimensions that accommodate a TeV-scale gravity, small black holes could be produced in near future accelerator experiments. Such small black holes, whose gravitational radius is much smaller than the characteristic size of extra dimensions can be very well described by asymptotically flat solutions, thus losing the information about the global geometry of the extra manifold. One might conclude that such small black holes would be indistinguishable in different scenarios. We argue that important differences still exist, especially regarding experimental signature in colliders, which may help us distinguish between the various extra dimensional scenarios. The main differences come from the fact that most of the models with the warped extra dimension have an additional discrete Z2 symmetry that makes the brane behave as if it were an infinite tension brane. 相似文献
7.
8.
Wen Wang Jian-Cun Rao Hua Ke Ming Feng Rui-Lin Xia Qing-Chang Meng De-Chang Jia Yu Zhou 《Journal of Sol-Gel Science and Technology》2010,56(1):87-92
We report the independent invention of perovskite ferroelectric nanowires strontium bismuth tantalate (SrBi2Ta2O9, SBT). Electrophoretic sol–gel techniques have been used successfully. The morphology and structures are analyzed via SEM,
TEM and XRD. SBT nanowires and nanoparticles filled template revealed 30 and 40 μm long, respectively. SBT are proved to be
a single phase of orthorhombic perovskite structure. As it indicated, SBT nanowires has been crystallized at 700 °C. To minimize
surface polarity, SBT nanowires oriented preferentially along the growing axis (c axis) by translation and rotation of atomic clusters of SBT. 相似文献
9.
This paper aims at exploring a digital image integration technique for multi-geoscience in formation dominated by airborne gamma-ray data, especially deeply discussing the method to secondly develop those aerial data by combining digital image processing system with the colored mapping system. Utilizing this technique , we have analyzed the geologic environment of uranium mineralization of Lianshanguan area > Liaoning Province, provided some important background information for further seeking of minerals. Meanwhile , experimental studies have been made to predict uranium mineralization , and evident results aquired. Practise shows that this new technique offers prospecting significance for mineral seeking and great practical value in survey of uranium resources. 相似文献
10.