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Visar resultat 21 - 25 av 32 avhandlingar som matchar ovanstående sökkriterier.

1. 21. Structure determination of beam sensitive crystals by rotation electron diffraction : the impact of sample cooling

   Författare :Fei Peng; Junliang Sun; Xiaodong Zou; Dag Nores; Ute Kolb; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron crystallography; rotation electron diffraction; structure determination; cooling; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Electron crystallography is complementary to X-ray crystallography. Single crystal X-ray diffraction requires the size of a crystal to be larger than about 5 × 5 × 5 μm3 while a TEM allows a million times smaller crystals being studied. This advantage of electron crystallography has been used to solve new structures of small crystals. LÄS MER

3. 22. Three-dimensional electron diffraction for studying order, disorder and flexibility in metal-organic frameworks

   Författare :Laura Samperisi; Xiaodong Zou; Sebastian Henke; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; continuous rotation electron diffraction; metal-organic frameworks; flexibility; rotational dynamics; atomic displacement parameters; anisotropic refinement; oorganisk kemi; Inorganic Chemistry;

   Sammanfattning : Metal-organic frameworks (MOFs) represent a class of 3D crystalline porous materials composed of organic linkers and metal nodes. Over the years, tens of thousands of MOF architectures have been developed, addressing various applications such as gas storage and separation, catalysis, chemical sensing, ion exchange and drug delivery. LÄS MER

4. 23. Novel framework materials : organically templated silicogermanates and hybrid fluorotitanates

   Författare :Liqiu Tang; Xiaodong Zou; Gunnar Svensson; Gies Hermann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; framework materials; silicogermanates; hybrid fluorotitananates; Chemistry; Kemi;

   Sammanfattning : Two types of novel framework materials, including six organically templated silicogermanates and five hybrid fluorotitanates, have been synthesized, and their structures have been determined by single crystal X-ray diffraction. Their structures and the interactions between the organic and inorganic species are discussed in some detail. LÄS MER

5. 24. Development of rotation electron diffraction as a fully automated and accurate method for structure determination

   Författare :Bin Wang; Xiaodong Zou; Andy Stewart; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron crystallography; structure determination; structure refinement; metal-organic framework; guest molecules; software development; automation; hierarchical cluster analyses; high-throughput data processing; data merging; frame orientations; least-squares optimization; data processing; TEM goniometer; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Over the past decade, electron diffraction methods have aroused more and more interest for micro-crystal structure determination. Compared to traditional X-ray diffraction, electron diffraction breaks the size limitation of the crystals studied, but at the same time it also suffers from much stronger dynamical effects. LÄS MER

7. 25. 3D Electron Diffraction : Application and Development towards High-quality Structure Determination

   Författare :Yunchen Wang; Wei Wan; Xiaodong Zou; Junliang Sun; Mauro Gemmi; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; three-dimensional electron diffraction; structure determination; rotation electron diffraction; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Electron crystallography has been proven to be effective for structure determination of nano- and micron-sized crystals. In the past few years, 3D electron diffraction (3DED) techniques were used for the structure solution of various types of complex structures such as zeolites, metal-organic frameworks (MOF) and pharmaceutical compounds. LÄS MER