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Online since: May 2015
Authors: Mohammed Gamil, Sahour Sayed, Ahmed Abd El Moneim Abd Elmoneim, Ahmed M.R. Fath El-Bab
The use of strain gauges is the most common way to detect dimensional changes in large structures as well as in delicate electronic applications.
Graphene has excellent electrical and mechanical properties, in addition to the merit of planar structure which makes it easily patterned if compared to CNTs [2].
Therefore; graphene-based flexible devices are attracting great attention due to the excellent properties of graphene regarding its planar structure, flexibility and high electron mobility as well as high strength [11, 12].
The images illustrate the overlapped flakes structure of the graphene film; the continuity of the flakes is held together by electrostatic forces (Van der Waals forces).
Saito: Physical Chemistry Chemical Physics Vol. 9 (2007), p. 1276 [22] Z.
Graphene has excellent electrical and mechanical properties, in addition to the merit of planar structure which makes it easily patterned if compared to CNTs [2].
Therefore; graphene-based flexible devices are attracting great attention due to the excellent properties of graphene regarding its planar structure, flexibility and high electron mobility as well as high strength [11, 12].
The images illustrate the overlapped flakes structure of the graphene film; the continuity of the flakes is held together by electrostatic forces (Van der Waals forces).
Saito: Physical Chemistry Chemical Physics Vol. 9 (2007), p. 1276 [22] Z.
Online since: August 2018
Authors: Da Ming Du, Fang Wang, Rui Hua Wang, Ai Xia Chen, Jie Guang Song, Cai Wen Li, Cheng Wei Hao, Lin Chen, Qiu Min Zou
Preparation and Characterization of Al2O3-Al Cermet with Coated Microstructure Using Powder Metallurgy Method
Ruihua Wang1, Aixia Chen1,a, Daming Du1, Fang Wang1, Caiwen Li1,
Qiumin Zou1, Jieguang Song2,b, Lin Chen2, Chengwei Hao3
1Engineering & Technology Research Center for Materials Surface Remanufacturing of Jiangxi Province, Jiujiang University, Jiujiang 332005 China
2Key Laboratory for Industrial Ceramics of Jiangxi Province, School of Materials and Chemistry Engineering, Pingxiang University, Pingxiang 337055 China
3School of Architecture and Civil Engineering, West Anhui University, Luan 237012, China
a93618054@qq.com, bsongjieguang@163.com
Keywords: Cermet; Al2O3; Al; coated microstructure; powder metallurgy method.
In this paper, the composite were prepared via the powder metallurgy method, because the powder metallurgy method is the first to manufacture metal matrix composite method, it can be prepared to enhance the volume fraction of very high levels of metal matrix composites, and is not the type of alloy matrix and reinforcing the type of restriction and attention[7-9].While the Al2O3 and Al combined to form a composite material having a special coated structure, the effectively improve the interface performance between the Al2O3 and Al is few studied, Al2O3-Al cermet with an coated microstructure are prepared by adjusting the preparing process in the paper, which provides the reference basis for the development to get good wear resistance, low thermal conductivity of the metal ceramic material.
The reasons for this phenomenon that the beginning of the sintering temperature is relatively low as the sample in the sintering process, when the sintering temperature is gradually increased, the sample porosity will be with the internal temperature increases as the declining, So that the internal structure of the sample also become more dense.
Because the melting point of Al is 660℃, the melting point of Al2O3 is 2050℃, the sintering temperature of sample is 900℃, Al powder is completely melted, while the Al2O3 powder is not, the combination type is mechanical bonding, the microstructure shows non-sintering densification and loose structure, Al is a dense phase with respect to Al2O3, and Al2O3 is non-dense phase.
And the prepared Al2O3-Al cermet adding sintering aids has a coated structure, which indicates that the large number of particles is migrated on the grain boundary during the sintering process, it improves to form the coated particles, the particles and particles effectively bonded to enhance the sample all aspects of performance.
In this paper, the composite were prepared via the powder metallurgy method, because the powder metallurgy method is the first to manufacture metal matrix composite method, it can be prepared to enhance the volume fraction of very high levels of metal matrix composites, and is not the type of alloy matrix and reinforcing the type of restriction and attention[7-9].While the Al2O3 and Al combined to form a composite material having a special coated structure, the effectively improve the interface performance between the Al2O3 and Al is few studied, Al2O3-Al cermet with an coated microstructure are prepared by adjusting the preparing process in the paper, which provides the reference basis for the development to get good wear resistance, low thermal conductivity of the metal ceramic material.
The reasons for this phenomenon that the beginning of the sintering temperature is relatively low as the sample in the sintering process, when the sintering temperature is gradually increased, the sample porosity will be with the internal temperature increases as the declining, So that the internal structure of the sample also become more dense.
Because the melting point of Al is 660℃, the melting point of Al2O3 is 2050℃, the sintering temperature of sample is 900℃, Al powder is completely melted, while the Al2O3 powder is not, the combination type is mechanical bonding, the microstructure shows non-sintering densification and loose structure, Al is a dense phase with respect to Al2O3, and Al2O3 is non-dense phase.
And the prepared Al2O3-Al cermet adding sintering aids has a coated structure, which indicates that the large number of particles is migrated on the grain boundary during the sintering process, it improves to form the coated particles, the particles and particles effectively bonded to enhance the sample all aspects of performance.
Online since: September 2018
Authors: Elena M. Evsina, Tamara V. Alykova, Natalia V. Zolotareva, Nariman M. Alykov
Mechanism of Ionic Associates Formation
It had been previously established [10] by us, that the flask represents aluminium silicate structures in the form of various linear and cyclic formations of the following type (1)-(3):
Si
O …
H2O
O
Si
O….
H2O O Si OН… H2O Fig.1 Aluminium silicate structures in the form of various linear and cyclic formations Si = O Si O O O = Si Si O OH Si = O Si O O O OH O = Si H2O H2O H2O H2O Fig. 2.
Aluminosilicate structures, Fig. 3.
Aluminosilicate structures, in the form of cyclic formations in the form of cyclic formations Other formations are possible.
Baron Handbook of physical-chemical variables book, Leningrad, Chemistry,1974
H2O O Si OН… H2O Fig.1 Aluminium silicate structures in the form of various linear and cyclic formations Si = O Si O O O = Si Si O OH Si = O Si O O O OH O = Si H2O H2O H2O H2O Fig. 2.
Aluminosilicate structures, Fig. 3.
Aluminosilicate structures, in the form of cyclic formations in the form of cyclic formations Other formations are possible.
Baron Handbook of physical-chemical variables book, Leningrad, Chemistry,1974
Online since: October 2008
Authors: David A. Jefferson, Volker Engels, Andrew E.H. Wheatley, Angel Berenguer-Murcia, Brian F.G. Johnson
Controlling
the size, shape, composition, and crystal structure of bimetallic nanoparticles continues to represent
a fundamental goal for researchers in this field, and over the last twenty years a number of
preparative methods have been developed to this end: the reduction-by-solvent (that is, the polyol
reduction) method [4] has become one of the most widely utilised.
Compositional influence on the size and structure of the resulting nanoparticles has been studied using a combination of High Resolution TEM, EDS and ICP spectroscopy.
Mean particle sizes as a function of the molar fraction of Pd Since core/shell structures have not previously been reported for the synthetic method used here, it stands to reason that a monometallic surface is unlikely to be determining the particles microstructure.
In this work, correlations between the colloid structure, and particularly the catalytically crucial particle surface with the mono- and bimetallic phases of the PdZn phase diagram [13], could not be established.
Vol. 100 (1996), p. 14430 [13] Landolt-Börnstein, Group IV Physical Chemistry / Vol. 5I (Springer, New York 1998).
Compositional influence on the size and structure of the resulting nanoparticles has been studied using a combination of High Resolution TEM, EDS and ICP spectroscopy.
Mean particle sizes as a function of the molar fraction of Pd Since core/shell structures have not previously been reported for the synthetic method used here, it stands to reason that a monometallic surface is unlikely to be determining the particles microstructure.
In this work, correlations between the colloid structure, and particularly the catalytically crucial particle surface with the mono- and bimetallic phases of the PdZn phase diagram [13], could not be established.
Vol. 100 (1996), p. 14430 [13] Landolt-Börnstein, Group IV Physical Chemistry / Vol. 5I (Springer, New York 1998).
Online since: December 2008
Authors: Katsutoshi Komeya, Junichi Tatami, Daisuke Hiratsuka, Kentarou Chihara, Fumihiro Wakai
High-Temperature Compressive Deformation of SiAlON Polycrystals
Prepared without Additives
Kentarou Chihara1,a
, Daisuke Hiratsuka
2, Junichi Tatami
2, Fumihiro Wakai1
and Katsutoshi Komeya2
1
Secure Materials Center, Materials and Structures Laboratory, Tokyo Institute of Technology,
4259 Nagatsuta, Midori, Yokohama 226-8503, Japan
2
Graduate School of Environment and Information Sciences, Yokohama National University,
79-9 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan
a
chihara-kentarou@sei.co.jp
Keywords: SiAlON, Grain Boundary, Intergranular Glass Phase, Deformation Mechanisms
Abstract.
Introduction SiAlONs, which are the solid solutions based on α- and β-silicon nitride (Si3N4), have an opportunity to prepare dense nitride ceramics without residual glass phase, because SiAlONs are able to accommodate oxide additives into their structures [1].
In spite of these unique structures of SiAlONs, if excess oxide additives and impurities exist, residual glass phase remains as thin films with the equilibrium thickness of a few nanometers at two-grain junctions and pockets at triple junctions [2,3].
The high-temperature deformation of SiAlON is strongly affected by volume fraction and chemistry of intergranular glass phase.
Accordingly, there has been great interest in controlling grain boundary structure in SiAlONs to improve the high-temperature strength and creep resistance [4-6].
Introduction SiAlONs, which are the solid solutions based on α- and β-silicon nitride (Si3N4), have an opportunity to prepare dense nitride ceramics without residual glass phase, because SiAlONs are able to accommodate oxide additives into their structures [1].
In spite of these unique structures of SiAlONs, if excess oxide additives and impurities exist, residual glass phase remains as thin films with the equilibrium thickness of a few nanometers at two-grain junctions and pockets at triple junctions [2,3].
The high-temperature deformation of SiAlON is strongly affected by volume fraction and chemistry of intergranular glass phase.
Accordingly, there has been great interest in controlling grain boundary structure in SiAlONs to improve the high-temperature strength and creep resistance [4-6].
Online since: July 2013
Authors: Zong Heng Yuan, Zhi Wei Liu, Rui Su
The structure parameters are listed in table 1.
Parameters of ledge parts are linked with the structure of major part, the value of w1 can’t be larger than 13 while w=40.
References Reference an article: [1] Kemal Gurel, Burkan Kaplan, Hasan Guner, Mehmet Bayindir, Aykutlu Dana, Resonant transmission of light through surface plasmon structures, J. applied physics. 94 (2009) 233102
[7] Weihao Liu, Renbin Zhong, Jun Zhou, Yaxin Zhang, Min Hu and Shenggang Liu, Investigations on a nano-scale periodical waveguide structure taking surface plasmon polaritons into consideration, J.
[12] L iu Qian, Zhang Zhe, Qi Zhimei, Study of Mesoporous-SiO2-Film-Modified surface plasmon resonance sensors with wavelength interrogation in near infrared region, J. chinese journal of analytical chemistry. 40 (2012) 556-562
Parameters of ledge parts are linked with the structure of major part, the value of w1 can’t be larger than 13 while w=40.
References Reference an article: [1] Kemal Gurel, Burkan Kaplan, Hasan Guner, Mehmet Bayindir, Aykutlu Dana, Resonant transmission of light through surface plasmon structures, J. applied physics. 94 (2009) 233102
[7] Weihao Liu, Renbin Zhong, Jun Zhou, Yaxin Zhang, Min Hu and Shenggang Liu, Investigations on a nano-scale periodical waveguide structure taking surface plasmon polaritons into consideration, J.
[12] L iu Qian, Zhang Zhe, Qi Zhimei, Study of Mesoporous-SiO2-Film-Modified surface plasmon resonance sensors with wavelength interrogation in near infrared region, J. chinese journal of analytical chemistry. 40 (2012) 556-562
Online since: November 2011
Authors: Yu Fang Zhu, Chen Peng, Chang Ming Wang, Ji Quan Yang
Introduction
‘Heterogeneous object’ refers to the object with spatially different material compositions or structures [1,2].
Structure of heterogeneous object manufacturing system Heterogeneous object manufacturing system is shown in Figure5, which includes computer, X and Y scanners, worktable and some dispensers.
Thus, the discrete export of material information and structure information is available synchronously
“Modeling the material grading and structures of heterogeneous objects for layered manufacturing”.
Analytical Chemistry. 2009, 81(13): 5474–5483
Structure of heterogeneous object manufacturing system Heterogeneous object manufacturing system is shown in Figure5, which includes computer, X and Y scanners, worktable and some dispensers.
Thus, the discrete export of material information and structure information is available synchronously
“Modeling the material grading and structures of heterogeneous objects for layered manufacturing”.
Analytical Chemistry. 2009, 81(13): 5474–5483
Online since: September 2007
Authors: P. Pirouz, M.A. Crimp, Andrew J. Trunek, Kevin M. Speer, J.T. Hile, C. Burda, Philip G. Neudeck, David J. Spry
., M.S. 77-1, Cleveland, OH 44135, USA
4
Dept. of Chemical Engineering & Materials Science, Michigan State University, 2527 Engineering
Building, East Lansing, MI 48824-1226, U.S.A.
5
Dept. of Chemistry, Case Western Reserve University, 10900 Euclid Ave.,
Cleveland, OH 44106-7204, USA
a
kevin.m.speer@case.edu
Keywords: 3C-SiC, Stacking faults, Partial dislocations, Electroluminescence, Electron channeling
contrast imaging.
Electronic band structure calculations have shown that SFs introduce a narrow energy band which splits from the conduction band minimum and extends into the bandgap of 4H-SiC [8,9]; this results in a reduction of excess carrier lifetimes [10], poor conductivity modulation [11], and a corequisite increase in forward voltage required to maintain constant levels of current.
Although some inconsistencies exist with this band structure model-namely, the observation of SF expansion in ptype 4H-SiC [12] - this degradation has effectively prevented beneficial commercialization of 4HSiC bipolar power devices.
Electronic band structure calculations could provide significant insight into this difference.
The elegance of such an electronic band structure model cannot be disputed; however, as previously mentioned, inconsistencies exist with this model that need to be addressed if it is to be truly conclusive.
Electronic band structure calculations have shown that SFs introduce a narrow energy band which splits from the conduction band minimum and extends into the bandgap of 4H-SiC [8,9]; this results in a reduction of excess carrier lifetimes [10], poor conductivity modulation [11], and a corequisite increase in forward voltage required to maintain constant levels of current.
Although some inconsistencies exist with this band structure model-namely, the observation of SF expansion in ptype 4H-SiC [12] - this degradation has effectively prevented beneficial commercialization of 4HSiC bipolar power devices.
Electronic band structure calculations could provide significant insight into this difference.
The elegance of such an electronic band structure model cannot be disputed; however, as previously mentioned, inconsistencies exist with this model that need to be addressed if it is to be truly conclusive.
Online since: February 2015
Authors: Maria V. Lyapunova, Victor S. Malkov
Introduction
Heterocyclic compounds are widespread in nature and play an important role in the chemistry of natural compounds along with proteins, fats and carbohydrates.
Besides, heterocyclic compounds can be used as dyes, structure-forming polymers, and also used in the production of plastics and in vulcanization of rubber.
The structure of the obtained compound is confirmed by IR and NMR spectrums (refer with: Fig. 4, Fig. 5, Fig. 6).
It is confirmed the structure of the obtained compound and the absence of impurities.
Lopyrev, Nitroazoles: Synthesis, Structure and Applications: Monography, Springer, New-York, 2009
Besides, heterocyclic compounds can be used as dyes, structure-forming polymers, and also used in the production of plastics and in vulcanization of rubber.
The structure of the obtained compound is confirmed by IR and NMR spectrums (refer with: Fig. 4, Fig. 5, Fig. 6).
It is confirmed the structure of the obtained compound and the absence of impurities.
Lopyrev, Nitroazoles: Synthesis, Structure and Applications: Monography, Springer, New-York, 2009
Online since: July 2015
Authors: Zalilah Murni Yunus, Norzila Othman, Rafidah Hamdan, Norfarihah Abu Kasin, Nur Solini Leman, Nurun Ruslan Najwa
It is proposed that H2SO4 provokes the pyrolytic decomposition of the precursor and the arrangemnet of the crosslinked structure [17].
Further observation indicated the diamaters have become larger as temperature increased to 490oC and 510oC speculated the damage of the walls’ structure [16] consequently lead to pores ruptures and reduce adsorption ability.
ULAC biosorption (cm-1) Identified Groups LAC biosorption (cm-1) Identified Groups 671.10 Alkynes; -C≡C-H: C-H bend 686.52 Alkynes; -C≡C-H: C-H bend 1099.21 Primary hydroxyl; stretching C-O 1110.75 Secondary hydroxyl, stretching C-O 1577.46 Aromatic structure; stretching C=C 1623.75 Aromatic structures, stretching C=C 2360.41 Alkyne triple bond, nitrile triple bonds 3307.28 Hydroxyl, carboxylic acid; stretching O-H, N-H pore zinc Fig. 3.
Surface chemistry and ion binding properties,” vol. 40, pp. 1493–1505, 2002
Further observation indicated the diamaters have become larger as temperature increased to 490oC and 510oC speculated the damage of the walls’ structure [16] consequently lead to pores ruptures and reduce adsorption ability.
ULAC biosorption (cm-1) Identified Groups LAC biosorption (cm-1) Identified Groups 671.10 Alkynes; -C≡C-H: C-H bend 686.52 Alkynes; -C≡C-H: C-H bend 1099.21 Primary hydroxyl; stretching C-O 1110.75 Secondary hydroxyl, stretching C-O 1577.46 Aromatic structure; stretching C=C 1623.75 Aromatic structures, stretching C=C 2360.41 Alkyne triple bond, nitrile triple bonds 3307.28 Hydroxyl, carboxylic acid; stretching O-H, N-H pore zinc Fig. 3.
Surface chemistry and ion binding properties,” vol. 40, pp. 1493–1505, 2002