Polyhedral Gold Nanoplate: High Fraction Synthesis of Two-Dimensional Nanoparticles through Rapid Heating Process

2008 ◽  
Vol 8 (8) ◽  
pp. 2638-2645 ◽  
Author(s):  
Jong-Hee Lee ◽  
Kai Kamada ◽  
Naoya Enomoto ◽  
Junichi Hojo

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Zhigang Li ◽  
Xiaoming Zhang ◽  
Yuichi Sugai ◽  
Jiren Wang ◽  
Kyuro Sasaki

Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1by a CO2gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results indicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which were increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal mass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore, char-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2, and specified that the source of Hydrocarbons is volatile matter from coal. Moreover, it was confirmed that generations of CO and Hydrocarbons gases are mainly dependent on coal temperature and O2concentration, and they are stimulated at temperature over 1000°C in the CO2-rich atmosphere.



2018 ◽  
Vol 15 ◽  
pp. 1055-1061
Author(s):  
Bin Zhu ◽  
Jia Zhu ◽  
Zhoujie Zhu ◽  
Yilin Wang ◽  
Yisheng Zhang


2007 ◽  
Vol 539-543 ◽  
pp. 4720-4725 ◽  
Author(s):  
A. Nagao ◽  
K. Hayashi ◽  
K. Oi ◽  
S. Mitao ◽  
N. Shikanai

The precipitation behavior of cementite in low carbon steels at various heating rates from 0.3 to 100 K/s has been studied using a high-frequency induction heating apparatus. The materials used in this study were steel platesfor welded structures: 610 and 780 MPa class steel plates with a mixed microstructure of bainite and martensite.Cementite was observed using a carbon extraction replica method and the hardness and toughness were also examined. When heated at the conventional slow rate of 0.3 K/s, relatively large cementite particles with an average diameter of 72 nm precipitated at the lath boundaries, whereas when heated at a rapid rate over 3.0 K/s, cementite precipitated both within the laths and at the lath boundaries, and the cementite was refined down to an average diameter of 54 nm. With such refinement of the cementite, the toughness was improved. On the other hand, the hardness was irrespective of the heating rate and was dependent on the tempering parameter. TEM observations of the cementite precipitation behavior during the rapid heating process revealed that cementite begins to precipitate at the lath boundaries at about 773 K and within the laths at about 873 K. It is concluded that rapid heating especially from 773 to 873 K contributes to the cementite refinement and consequently the improvement in toughness. The effect of alloying elements such as chromium, molybdenum or silicon on the cementite growth during the rapid heating and tempering treatment is also discussed.



2011 ◽  
Vol 79 ◽  
pp. 105-110
Author(s):  
Guo Jun Li ◽  
Xiao Ting Li ◽  
Hai Geng Chen

The most effective way of determining the whole billet temperature field is to use a simulation model. Large amount of calculation as well as computational time is consumed to employ two-dimensional finite difference method since the heating process is extremely complex, then it’s necessary to simplify the calculation process. In this paper, a simplified method in one-dimension format was presented to calculate two-dimensional heat conduction equations of heating slab. The billet simulated was placed in a changeable thermal flux boundary environment, in which the thermal flux was proportional to fourth power of temperature. During the heating process, the changeable parameters were taken into account: i. e different billet dimensions, different billet thermal conduction, different specific heat, etc. The comparision between results of two-dimensional finite difference method and the simplified method verified that the simplified method can satisfy accuracy requirement as well as calculation time saving, which enable the simplified method online using.



1988 ◽  
Vol 144 ◽  
Author(s):  
F. K. Yang ◽  
S. J. Pien ◽  
R. Kwor

ABSTRACTA thermal analysis is performed to simulate the rapid heating process for ion implanted GaAs with consideration of the doping effect. The results are for cases with various concentrations and thicknesses of doping layer. Also studied are the heating processes for silicon dioxide capped GaAs. The effects of the thickness of the oxide layer are discussed. The magnitude of the temperature differences across the wafer is addressed. The present analysis considers xenon-arc lamps and tungsten-halogen lamps as the light sources.



2005 ◽  
Vol 59 (5) ◽  
pp. 620-629 ◽  
Author(s):  
Jinggang Zhao ◽  
Kenji Tatani ◽  
Yukihiro Ozaki

Infrared (IR) spectra of FLC-154 (FLC: ferroelectric liquid crystal) with monotropic phase transition under a nonalignment state with a sample layer thickness of 24.5 μm were measured for heating process from 55 to 90 °C and a cooling process from 90 to 55 °C in increments of 1 °C. The thermal dynamics of FLC-154 were investigated by use of IR spectroscopy combined with principal component analysis (PCA) and sample–sample two-dimensional (2D) correlation spectroscopy. During the cooling, the FLC-154 molecule passes through the monotropic smectic- C* (Sm- C*) phase, which is transformed from the Sm- A phase. The results from PCA suggest that during the heating process, the thermal dynamics of the alkyl chains, core moiety, and C=O groups are similar to each other. Furthermore, PCA and sample–sample 2D correlation spectroscopy indicate that the alkyl chains and C=O groups in the chiral and core moieties are responsible for the emergence of the Sm- C* phase. This conclusion is very important because the IR data have given more evident cause for the emergence of the Sm- C* phase than the theoretical models such as the molecular-statistical theory of ferroelectric ordering and the indigenous polarization theory. Moreover, it has been found that some of the trans conformations of the alkyl chains of FLC-154 change partly to the gauche conformation when the phase transition from the crystalline phase to the Sm- A phase occurs. It has also been found that the intermolecular interactions of the C=O group in the core moiety in the Sm- A phase are weaker than those in the crystalline phase and that the conformational change occurs on the C–O–C bonds in the core moiety upon going from the crystalline to the Sm- A phase.



2005 ◽  
Vol 34 (3) ◽  
pp. 328-329 ◽  
Author(s):  
Takeo Yamada ◽  
Haoshen Zhou ◽  
Itaru Honma ◽  
Yuko Ueno ◽  
Tsutomu Horiuchi ◽  
...  


2020 ◽  
Vol 10 (15) ◽  
pp. 5174
Author(s):  
Junhui Xiao ◽  
Chao Chen ◽  
Wei Ding ◽  
Yang Peng ◽  
Kai Zou ◽  
...  

In this study, a one-step rapid heating novel process was used to prepare high-purity anhydrous scandium chloride molten salt with low-purity scandium oxide. High-purity anhydrous ScCl3 molten salt was used as the Sc-bearing raw material for preparing the Sc-bearing master alloy. Inert gas was used to enhance the purity of anhydrous scandium chloride and reduce the hydrolysis rate of scandium. The results show that high-purity scandium chloride (purity, 99.69%) with the scandium content of 29.61%, was obtained, and the hydrolysis rate of scandium was 1.19% under the conditions used: removing ammonium chloride; residual crystal water temperature of 400 °C; m(Sc2O3):m(NH4Cl) = 1:2.5; holding-time of 90 min; heating-rate of 12 °C/min; and argon flow of 7.5 L/min. XRD, SEM, and EPMA analyses further verified that anhydrous scandium chloride crystallization condition was relatively good and the purity of high-purity anhydrous scandium chloride approached the theory purity of anhydrous scandium chloride.



Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 694 ◽  
Author(s):  
Gorka Larzabal ◽  
Nerea Isasti ◽  
Jose Rodriguez-Ibabe ◽  
Pello Uranga

Cost-effective advanced design concepts are becoming more common in the production of thick plates in order to meet demanding market requirements. Accordingly, precipitation strengthening mechanisms are extensively employed in thin strip products, because they enhance the final properties by using a coiling optimization strategy. Nevertheless, and specifically for thick plate production, the formation of effective precipitation during continuous cooling after hot rolling is more challenging. With the aim of gaining further knowledge about this strengthening mechanism, plate hot rolling conditions were reproduced in low carbon Ti-Mo microalloyed steel through laboratory simulation tests to generate different hot-rolled microstructures. Subsequently, a rapid heating process was applied in order to simulate induction heat treatment conditions. The results indicated that the nature of the matrix microstructure (i.e., ferrite, bainite) affects the achieved precipitation hardening, while the balance between strength and toughness depends on the hot-rolled microstructure.





Sign in / Sign up

Export Citation Format

Share Document