Microstructure and formation mechanism of combustion-synthesized rodlike Ca α-sialon crystals

2001 ◽  
Vol 16 (7) ◽  
pp. 1928-1934 ◽  
Author(s):  
Kexin Chen ◽  
Haibo Jin ◽  
M. Oliveira ◽  
Heping Zhou ◽  
J. M. F. Ferreira
Keyword(s):  
Reaction Mechanism ◽  
Combustion Synthesis ◽  
Formation Mechanism ◽  
Particle Morphology ◽  
Morphological Features ◽  
Combustion Reaction ◽  
Synthesis Process ◽  
Two Dimensional ◽  
High Productivity ◽  
The Relationship

The fabrication of rodlike Ca α-sialon crystals through a combustion synthesis process is reported in this paper. The main morphological features in the product included rodlike crystals, two dimensional elongated platelets, and equiaxed particles. By proper adjustment of the combustion parameters, a high productivity of rodlike Ca α-sialon crystals in the final product could be achieved. The combustion reaction mechanism and the relationship between the combustion parameters and the particle morphology were investigated.

A micromechanistic model of the combustion synthesis process: Influence of intrinsic kinetics

1998 ◽  
Vol 13 (8) ◽  
pp. 2269-2280 ◽  
Author(s):  
Cheng He ◽  
Chantal Blanchetiere ◽  
Gregory C. Stangle
Keyword(s):  
Pore Size ◽  
Combustion Synthesis ◽  
Kinetic Mechanism ◽  
Product Formation ◽  
Point Of View ◽  
Synthesis Process ◽  
Intrinsic Kinetics ◽  
Physical And Chemical ◽  
The Relationship ◽  
Proper Balance

A micromechanistic model of the combustion synthesis of NbC has been developed by combining the results of an experimental study of the intrinsic, pore-level kinetic mechanism [C. He. and G. C. Stangle, J. Mater. Res. 10, 2829–2841 (1995)] and a theoretical model developed previously [Y. Zhang and G. C. Stangle, J. Mater. Res. 9, 2592–2604 (1994); 9, 2605–2619 (1994)], in order to account for the various physical and chemical processes that take place during the combustion synthesis process. Results of the present investigation are interpreted from both a macroscopic and a microscopic point of view. Moreover, the relationship between the microscopic processes and macroscopic features of the combustion synthesis process is discussed. The results show that the formation of a combustion wave in the Nb-C system corresponded to establishment of a proper balance between the rates of enthalpy redistribution within the sample. Furthermore, the pore size had a significant influence on the combustion synthesis process: smaller pores gave rise to a higher area of contact between the reactants, which in turn gave rise to a higher rate of enthalpy increase due to the enhanced rate of product formation. The influence of the pore size distribution on the process is also discussed.

Combustion Synthesis of Ti(C,N) Powder

2007 ◽  
Vol 280-283 ◽  
pp. 1421-1424 ◽  
Author(s):  
Yan An Wang ◽  
Ke Xin Chen ◽  
He Ping Zhou
Keyword(s):  
Reaction Mechanism ◽  
Combustion Synthesis ◽  
Phase Formation ◽  
Combustion Temperature ◽  
Nitrogen Pressure ◽  
Nitrogen Atmosphere ◽  
Titanium Carbonitride ◽  
Synthesis Process ◽  
Reaction Parameters ◽  
N Powder

Titanium carbonitride powders were synthesized directly by a combustion synthesis process between titanium and carbon in a nitrogen atmosphere. The relationships between properties of the final product and the combustion reaction parameters were systematically investigated. Especially, the effects of nitrogen pressure on the phase formation and microstructure of the as-synthesized products were experimentally investigated. The reaction mechanism of Ti(C,N) was proposed through quench experiment, the variation of combustion temperature on time and thermodynamics analysis.

scholarly journals Template-Free Self-Assembly of Two-Dimensional Polymers into Nano/Microstructured Materials

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3310
Author(s):  
Shengda Liu ◽  
Jiayun Xu ◽  
Xiumei Li ◽  
Tengfei Yan ◽  
Shuangjiang Yu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Recent Progress ◽  
Two Dimensional ◽  
Subsequent Removal ◽  
The Past ◽  
2D Polymers ◽  
Template Free ◽  
Self Assembled ◽  
The Relationship ◽  
Polymer Tubes

In the past few decades, enormous efforts have been made to synthesize covalent polymer nano/microstructured materials with specific morphologies, due to the relationship between their structures and functions. Up to now, the formation of most of these structures often requires either templates or preorganization in order to construct a specific structure before, and then the subsequent removal of previous templates to form a desired structure, on account of the lack of “self-error-correcting” properties of reversible interactions in polymers. The above processes are time-consuming and tedious. A template-free, self-assembled strategy as a “bottom-up” route to fabricate well-defined nano/microstructures remains a challenge. Herein, we introduce the recent progress in template-free, self-assembled nano/microstructures formed by covalent two-dimensional (2D) polymers, such as polymer capsules, polymer films, polymer tubes and polymer rings.

EQUIVALENCE OF TWO-DIMENSIONAL GRAVITIES

1990 ◽  
Vol 05 (16) ◽  
pp. 1251-1258 ◽  
Author(s):  
NOUREDDINE MOHAMMEDI
Keyword(s):  
Gauge Theory ◽  
Explicit Solution ◽  
Light Cone ◽  
Equations Of Motion ◽  
Two Dimensional ◽  
Induced Gravity ◽  
Light Cone Gauge ◽  
Dimensional Gravity ◽  
The Relationship ◽  
Chern Simons

We find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL (2, R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2+1 dimensional gravity. We present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given.

“Beholding the Man”: Viewing (or is it Marking?) John’s Trial Scene alongside Kitsch Art

2016 ◽  
Vol 24 (2) ◽  
pp. 245-264
Author(s):  
Andrew P. Wilson
Keyword(s):  
Two Dimensional ◽  
Devotional Art ◽  
The People ◽  
Subject And Object ◽  
Ecce Homo ◽  
Small Stories ◽  
John's Gospel ◽  
Relationship Of ◽  
The Relationship ◽  
Point Of Departure

One of the grand scenes of the Passion narratives can be found in John’s Gospel where Pilate, presenting Jesus to the people, proclaims “Behold the man”: “Ecce Homo.” But what exactly does Pilate mean when he asks the reader to “Behold”? This paper takes as its point of departure a roughly drawn picture of Jesus in the “Ecce Homo” tradition and explores the relationship of this picture to its referent in John’s Gospel, via its capacity as kitsch devotional art. Contemporary scholarship on kitsch focuses on what kitsch does, or how it functions, rather than assessing what it is. From this perspective, when “beholding” is understood not for what it reveals but for what it does, John’s scene takes on a very different significance. It becomes a scene that breaks down traditional divisions between big and small stories, subject and object as well as text and context. A kitsch perspective opens up possibilities for locating John’s narrative in unexpected places and experiences. Rather than being a two-dimensional departure from the grandeur of John’s trial scene, kitsch “art” actually provides a lens through which the themes and dynamics of the narrative can be re-viewed with an expansiveness somewhat lacking from more traditional commentary.


Numerical Analysis of Bridge Expansion-Induced Rail Deformation of Ballast Truck

2014 ◽  
Vol 580-583 ◽  
pp. 3208-3214 ◽  
Author(s):  
Zhen Wei Xiong ◽  
Xin Ling Liang ◽  
Xian Xing Dai ◽  
Ping Wang
Keyword(s):  
Granular Flow ◽  
Element Model ◽  
Discrete Element Model ◽  
Board Structure ◽  
Vertical Deformation ◽  
Two Dimensional ◽  
Running Safety ◽  
Bridge Plate ◽  
Ballast Track ◽  
The Relationship

when the ballast track stretch with the bridge, ballast which is near expansion joint will move confusedly. As a result, rail produced vertical deformation. The deformation will affect the running safety and comfortability of train. At present, there are two kinds of treatments which are cover board structure and baffle structure to deal ballast’s movement. Aiming at the different modes of stretching when the two kinds of structures and different arrangement condition of bridge plate are applied, the rail-sleeper-ballast discrete element model is developed by the method of two-dimensional granular flow. The relationship between rail deformation and bridge expansion is analyzed on the foundation of the model. Results show as flows: when bridge extends or shortens, rail always produced upwarp deformation. Bridge plate should arrange asymmetrically. Like this, the rail deformation decrease by 40%. And adopting the baffle structure can effectively reduce the influence of bridge expansion in ballast truck.

Combustion reaction mechanism of four typical Chinese biomass by TG and DTG

2011 ◽  
Vol 7 ◽  
pp. S209-S215 ◽  
Author(s):  
Pei-Sheng Li ◽  
Qin Wang ◽  
Qiao Xu ◽  
Wan Yu ◽  
Ya-Nan Yue ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Combustion Reaction ◽  
Tg And Dtg

A Convenient Method for Preparing Well-Dispersed Er2Zr2O7 Nanocrystals

2010 ◽  
Vol 123-125 ◽  
pp. 611-614 ◽  
Author(s):  
Yu Ping Tong ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao ◽  
Chang Yong Li
Keyword(s):  
Particle Size ◽  
Combustion Synthesis ◽  
Crystal Size ◽  
Lattice Distortion ◽  
Combustion Method ◽  
Treatment Temperature ◽  
Synthesis Process ◽  
Thermal Treatment Temperature ◽  
Average Size ◽  
Xrd And Tem

Well-dispersed fluorite Er2Zr2O7 nanocrystals have been successfully prepared by a convenient salt-assistant combustion method. The effects of calcinations temperature and salt category on the characteristics of the products were investigated by XRD and TEM. The thermal treatment temperature has an important effect on crystal size and lattice distortion of the nanocrystals. The experiment showed that the introduction of salt in the combustion synthesis process resulted in the formation of well-dispersed Er2Zr2O7 nanocrystals. The average size was 30 nm and was in agreement with the XRD result, which indicated that the nanocrystals were uniform in particle size distribution. Moreover, the possible formation process in the salt-assisted combustion synthesis was also analyzed.

Latest Research and Developing Tendency of Hyperbranched Polymers Fabrication

2021 ◽  
Vol 896 ◽  
pp. 45-50
Author(s):  
Lian Yi Huo ◽  
Xue Tao Shi ◽  
Si Ming Chen ◽  
Meng Yao Zhang
Keyword(s):  
Reaction Mechanism ◽  
Ring Opening ◽  
Hyperbranched Polymers ◽  
Ring Opening Polymerization ◽  
Synthesis Process ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Environmental Friendly ◽  
High Efficient ◽  
The Future

Hyperbranched polymers (HBPs) have been applied in various fields because of its outstanding biodegradability and biocompatibility. At present, there are a variety of methods that are used to fabricate HBPs, such as polycondensation, reactive polymerization and ring-opening polymerization according to reaction mechanism. These methods are all environmental-friendly and high-efficient to generate HBPs, and are valuable for industrialization. In this work, we conclude some common methods of HBPs fabrication and make the comparison between them to analyze their advantages and disadvantages, which contribute in how to improve the synthesis process in the future research.

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