An Improved Receptor-Based Pharmacophore Generation Algorithm Guided by Atomic Chemical Characteristics and Hybridization Types

Technique of Extrusion Die Tolerance Analysis Based on CAT

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.941-944.1777 ◽

2014 ◽

Vol 941-944 ◽

pp. 1777-1781

Author(s):

Yuan Lou Gao ◽

Zhe Li ◽

Xin Wang

Keyword(s):

Manufacturing Process ◽

Tolerance Analysis ◽

Chemical Characteristics ◽

Tolerance Design ◽

Generation Algorithm ◽

Extrusion Die ◽

Tolerance Modeling ◽

Screw Extrusion ◽

Computer Aided ◽

Manual Calculation

As traditional screw extrusion die tolerance analysis has characteristics like manual calculation, experience dependence so far, this paper aims at applying CAT (Computer Aided Tolerancing) into extrusion field with the assistance of tolerance modeling and self-generation algorithm of retrieval dimension chain to analyze tolerance and reassign tolerance based on the technology used for aircraft assembly referring to chemical characteristics of the manufacturing process. Practice on production line testified the rationality of improved tolerance design.

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Characterization of defects in tabular silver halide grains

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178367 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1046-1047

Author(s):

C. Goessens ◽

D. Schryvers ◽

J. Van Landuyt ◽

A. Verbeeck ◽

R. De Keyzer

Keyword(s):

Radiation Damage ◽

Silver Halide ◽

Chemical Characteristics ◽

X Ray ◽

Free Region ◽

Central Defect ◽

Crystallographic Defects ◽

Physical And Chemical ◽

Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

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