Effect of surface roughness of carbon support films on high-resolution electron diffraction of two-dimensional protein crystals

1991 ◽  
Vol 36 (4) ◽  
pp. 307-318 ◽  
Author(s):  
H.-J. Butt ◽  
D.N. Wang ◽  
P.K. Hansma ◽  
W. Kühlbrandt
Keyword(s):  
Surface Roughness ◽  
High Resolution ◽  
Electron Diffraction ◽  
Carbon Support ◽  
Protein Crystals ◽  
Two Dimensional ◽  
Resolution Electron ◽  
Effect Of Surface

Low dose electron diffraction of wet protein crystals

1978 ◽  
Vol 36 (2) ◽  
pp. 6-7
Author(s):  
B.B. Chang ◽  
D.F. Parsons
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Radiation Damage ◽  
Low Dose ◽  
Protein Crystal ◽  
Protein Crystals ◽  
Electron Dose ◽  
Resolution Electron ◽  
Diffraction Patterns ◽  
Iterative Procedures

High resolution electron diffraction patterns from wet unstained protein-crystals have been successfully obtained by using very low electron dose (∽10-2 e/Å2, much smaller dose than used by Unwin and Henderson (1975) for electron diffraction of their crystals). This enabled us to follow the radiation damage of the protein crystal due to increasing dosage by recording successive diffraction patterns given by the same crystal. Changes in intensities of both the high and the low order reflections can be studied. Another important consequence is that very low dose electron diffraction can be obtained from the same crystal and iterative procedures such as Gerchberg and Saxton's technique can be applied.The electron diffraction work with very low dose was performed at 200 kV using the environmental chamber in the Jeolco 200. To achieve best electron diffraction conditions with the specimen in the hydration chamber, the objective and intermediate lens currents have been changed.

Two-Dimensional Antiphase Structure in The Ordered Ternary Alloy Cu-Zn-Au

1983 ◽  
Vol 21 ◽  
Author(s):  
D. Watanabe ◽  
K. Sato ◽  
R. Miida
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Two Dimensional ◽  
Structure Model ◽  
Ordered Structures ◽  
Resolution Electron ◽  
Zn Content ◽  
High Resolution Electron Microscope

ABSTRACTOrdered structures of Cu-Zn-Au alloys were studied by electron diffraction. Two-dimensional antiphase structures exist at the compositions, Cu55Zn15Au30, Cu80-xZnxAu20 (10 ≤ x ≤ 35) and Cu85-xZnxAu15(25 ≤ x ≤ 35). The domain sizes M's measured in terms of the basic L12 cell along the two orthogonal directions are always the same, and they change from 3.4 to 1.6 as Zn content increases from 10 to 35 at.%. Based on the superstructure image of the Cu55Zn25Au20 with M=2.0 taken with high-resolution electron microscope, a structure model is derived, which explains intensities of all the superlattice spots on the diffraction pattern.

Zur Darstellung und Struktur einer neuen FeNbO4-Modifikation.

1976 ◽  
Vol 31 (3) ◽  
pp. 318-320b ◽  
Author(s):  
Herbert Brunner ◽  
Reginald Gruehn
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Chemical Transport ◽  
High Resolution Electron Microscopy ◽  
Monoclinic Space Group ◽  
Two Dimensional ◽  
Detailed Structure ◽  
Space Group ◽  
Resolution Electron

Three different polymorphs of FeNbO4 were prepared by chemical transport. One of them is a new modification, which crystallisizes in the GaNbO4-type, monoclinic, space group C2, a = 12.52 Å; b= 3.83 Å; c = 6.67 A; β = 107.5°. The detailed structure, composed of 2 x 2 ‘blocks’ of corner shared metal-oxygen octahedra, was investigated by electron-diffraction and two-dimensional high resolution electron microscopy.

Microstructural Studies of the WO3/TiO2 Monolayer Catalyst System Using High Resolution Electron Microscopy

1994 ◽  
Vol 344 ◽  
Author(s):  
A. Burrows ◽  
C. J. Kiely ◽  
R. W. Joyner ◽  
H. Knözinger ◽  
F. Lange
Keyword(s):  
Electron Microscopy ◽  
Surface Roughness ◽  
High Resolution ◽  
Structural Models ◽  
High Resolution Electron Microscopy ◽  
Catalyst System ◽  
Mechanical Mixing ◽  
Chemical Methods ◽  
Resolution Electron ◽  
Microstructural Studies

AbstractWe have characterised the WO3T'iO2 (anatase) catalyst system using High Resolution Electron Microscopy. We will show that the overlayer preserves the surface roughness of titania and consists of 2D-hexagonal clusters that have a definite orientation relationship with the support. The contrast observed from these clusters is discussed in terms of existing structural models. A comparison between traditional chemical methods of preparation and simple mechanical mixing is made to assess the effectiveness of the latter to disperse WO3.

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