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Online since: January 2017
Authors: Fen Xu, Yong Jin Zou, Hai Liang Chu, Zi Qiang Wang, Tian Bao Yang, Li Xian Sun
Loh et al [8] have described structure directing role that benzoic acid functionalized graphene played in the nanowires of MOF-5 synthesis.
The remove of water of crystallization lead to the quick loss at about 300 oC, and the structure begin to decompose subsequently.
This phenomenon could be attributed the structure destroy by GO in large amount content.
Too much changed structure could be responsible for this phenomenon.
Falcaro: Journal of Materials Chemistry A, Vol. 1 (2013) No.42, p.13033
The remove of water of crystallization lead to the quick loss at about 300 oC, and the structure begin to decompose subsequently.
This phenomenon could be attributed the structure destroy by GO in large amount content.
Too much changed structure could be responsible for this phenomenon.
Falcaro: Journal of Materials Chemistry A, Vol. 1 (2013) No.42, p.13033
Online since: November 2014
Authors: Su Ping Cui, Ya Li Wang, Zi Ming Wang, Qian Jin Mao, Yan Zheng
In the last 50 years, many new experimental tools to investigate the structure and the chemical composition of nanostructured materials have become available.
Dynamic research methods consist of hydration heat method, hydration dynamic method, electrical resistivity method, environmental scanning electron microscopy and electrochemistry method; Static research methods consists of chemistry combined water, CH quantitative testing, X-ray diffraction and scanning electron microscopy.
Generally speaking, NMR spectroscopy is most sensitive to the local ordering and structure around the spin nucleus, and this permits structural studies not only of crystalline minerals, but also of poorly crystalline and amorphous materials, such as the calium silicate hydration products produced in the setting of Portland cement.
On the other hand, it can quantitatively determine the phase structure and content of the cement.
It was indicated that BSE technique had some distinctive advantages for cement studied, and it can quantitatively determine the phase structure and content of the cement.
Dynamic research methods consist of hydration heat method, hydration dynamic method, electrical resistivity method, environmental scanning electron microscopy and electrochemistry method; Static research methods consists of chemistry combined water, CH quantitative testing, X-ray diffraction and scanning electron microscopy.
Generally speaking, NMR spectroscopy is most sensitive to the local ordering and structure around the spin nucleus, and this permits structural studies not only of crystalline minerals, but also of poorly crystalline and amorphous materials, such as the calium silicate hydration products produced in the setting of Portland cement.
On the other hand, it can quantitatively determine the phase structure and content of the cement.
It was indicated that BSE technique had some distinctive advantages for cement studied, and it can quantitatively determine the phase structure and content of the cement.
Online since: May 2021
Authors: Nikolay Polushin, Razhudin Rizakhanov, Elena Vysotina, Aleksandr Mishanin, Sergey Sigalaev, Vadim Shokorov
However, an introduction of impurities with a diameter bigger than a carbon atom diameter is a very difficult task to implement because of a dense structure and a rigidity of a diamond lattice.
Plasma-chemical etching and metallization procedures do not affect the structure of a polycrystalline diamond film.
Aleksenko of the Institute of Physical Chemistry and Electrochemistry RAS, Moscow, Russia for the help in the preparation of boron-doped polycrystalline diamond films.
Barinov, Semiconductor strain gauge pressure sensors based on silicon-on-insulator structure, J.
Spitsyn and et al, Diamond thin-film heterogeneous structures for pressure sensors, Proceedings of 13th International Conference “Films and Coatings-2017”, St.
Plasma-chemical etching and metallization procedures do not affect the structure of a polycrystalline diamond film.
Aleksenko of the Institute of Physical Chemistry and Electrochemistry RAS, Moscow, Russia for the help in the preparation of boron-doped polycrystalline diamond films.
Barinov, Semiconductor strain gauge pressure sensors based on silicon-on-insulator structure, J.
Spitsyn and et al, Diamond thin-film heterogeneous structures for pressure sensors, Proceedings of 13th International Conference “Films and Coatings-2017”, St.
Online since: January 2016
Authors: Mashitah Mohd Yusoff, Gomaa A. M. Ali, Kwok Feng Chong, Salah A. Makhlouf, Osama A. Fouad
Yusoff1,d, KWOK Feng Chong1,e*
1 Faculty of Industrial Science and Technology, University Malaysia Pahang (UMP), 26300, Kuantan, Pahang, Malaysia
2 Chemistry Department, Faculty of Science, Al–Azhar University, Assiut branch, Assiut 71524, Egypt
3 Central Metallurgical Research and Development Institute, CMRDI, P.O.
Results and Discussion Crystal structure and phase analysis.
Further information about the chemical structure was obtained from FTIR data presented in Fig. 2(a).
The energy gaps were found to be 1.95 and 1.35 eV suggesting direct allowed transitions, being consistent with the Co3O4 band structure.
These results are much higher than those reported for Co3O4 nanowires (336 Fg-1 at 1 Ag-1) [1] and layered parallel folding structure of mesoporous Co3O4 (202.5 Fg-1 at 1 Ag-1) [8].
Results and Discussion Crystal structure and phase analysis.
Further information about the chemical structure was obtained from FTIR data presented in Fig. 2(a).
The energy gaps were found to be 1.95 and 1.35 eV suggesting direct allowed transitions, being consistent with the Co3O4 band structure.
These results are much higher than those reported for Co3O4 nanowires (336 Fg-1 at 1 Ag-1) [1] and layered parallel folding structure of mesoporous Co3O4 (202.5 Fg-1 at 1 Ag-1) [8].
Online since: May 2022
Authors: Yeng Fong Shih, Jia Yi Xu, Ying Hsiao Chen
Vanillin-Based Polyimine Vitrimer: Self-Healing and Physical Properties
Yeng-Fong Shih1,a, Jia-Yi Xu2,b*, Ying-Hsiao Chen3,c
1,2,3Department of Applied Chemistry, Chaoyang University of Technology, No. 168, Jifeng E.
However they cannot be recycled due to their cross-linked network structure.
BV was synthesized by the nucleophilic substitution reaction of vanillin with 1,3,5-tris(bromomethyl)benzene, and its chemical structure was confirmed by 13C NMR and FTIR in Fig 2 and Fig 3, respectively.
As shown in Fig. 5(a), BVD-2 has the highest tensile strength of 49.81 MPa, which is presumed that the BV monomer bearded a polybenzene ring structure.
This behavior was attributed to the lower amine ratio in the BVD-2 resulting in higher stacked structures; therefore, the higher char residues could be obtained.[13].
However they cannot be recycled due to their cross-linked network structure.
BV was synthesized by the nucleophilic substitution reaction of vanillin with 1,3,5-tris(bromomethyl)benzene, and its chemical structure was confirmed by 13C NMR and FTIR in Fig 2 and Fig 3, respectively.
As shown in Fig. 5(a), BVD-2 has the highest tensile strength of 49.81 MPa, which is presumed that the BV monomer bearded a polybenzene ring structure.
This behavior was attributed to the lower amine ratio in the BVD-2 resulting in higher stacked structures; therefore, the higher char residues could be obtained.[13].
Online since: October 2011
Authors: Azlan Abdul Aziz, Abdul Razak Khairunisak, Rahmah Noordin, Rabizah Makhsin Siti
This method is simple but the major drawbacks are the spherical structure of AuNPs produced is difficult to control after the size exceeds 30 nm and becomes polydisperse.
The seeded-growth method offers many advantages such as able to produce monodisperse structure and easy to control the size, shape and dimension of AuNPs [6].
Therefore, the degree of supersaturation is attained at longer period resulting in non-homogenize and elliptical structure as shown in Figs. 1(a – b).
Therefore, the bulk and cluster structures of AuNPs are formed as in Fig. 5 (f).
Kachru: Food Chemistry Vol. 122 (2010), p. 1298–1303 [5] A.
The seeded-growth method offers many advantages such as able to produce monodisperse structure and easy to control the size, shape and dimension of AuNPs [6].
Therefore, the degree of supersaturation is attained at longer period resulting in non-homogenize and elliptical structure as shown in Figs. 1(a – b).
Therefore, the bulk and cluster structures of AuNPs are formed as in Fig. 5 (f).
Kachru: Food Chemistry Vol. 122 (2010), p. 1298–1303 [5] A.
Online since: January 2009
Authors: Ze Bing Xing, Xu Dong Wang, Shuang Ping Lin, Xue Kuan Su, Zuo-Ren Nie
Fig.1 Optical microstructure in transversal surfaces of intergranular corrosion
a) 1# alloy b) 2# alloy c) 3# alloy d) 4# alloy
The experiment alloy should form a oxide film in air, which has the γ-Al2O3 structure, e.g. spinal
structure.
When it enters the oxide film, Er can reduce the vacancy of the face due to Er has the same structure with the γ-Al2O3, thus oxide will become much condensation.
The structure of the grain boundary plays a very important role in SCC.
Influence of Aging Treatment on the Grain Boundary Precipitation and Chemistry in 7075Al Alloy [J ].
Research on Rare earth in Aluminum, Materials Science Forum, Cambridge, UK,2002(396-402): 1731-1735 [8] Yang Hui, Including rare earth aluminum alloy surface oxide film structure and performance relations research,.
When it enters the oxide film, Er can reduce the vacancy of the face due to Er has the same structure with the γ-Al2O3, thus oxide will become much condensation.
The structure of the grain boundary plays a very important role in SCC.
Influence of Aging Treatment on the Grain Boundary Precipitation and Chemistry in 7075Al Alloy [J ].
Research on Rare earth in Aluminum, Materials Science Forum, Cambridge, UK,2002(396-402): 1731-1735 [8] Yang Hui, Including rare earth aluminum alloy surface oxide film structure and performance relations research,.
Online since: January 2007
Authors: Ahmet Güral, Metin Gürü, Süleyman Tekeli
Results and discussion
Fig. 1 shows the microstructures of the tempered martensite structure quenched from 890°C and
tempered at 200°C and 600°C, respectively.
A typical tempered martensite structure was obtained at 200°C (Fig. 1a-b), whereas an over-tempered martensite structure was observed at 600°C (Fig. 1cd).
The precipitation of very small cementite particles in the martensite structure can also be seen in the over-tempered specimens.
Martensitic structure completely disappeared in the specimens tempered at 600°C and thus, the wear coefficient increased.
Narasimhan, K.S: Materials Chemistry and Physics, Vol.67 (2001), p.56
A typical tempered martensite structure was obtained at 200°C (Fig. 1a-b), whereas an over-tempered martensite structure was observed at 600°C (Fig. 1cd).
The precipitation of very small cementite particles in the martensite structure can also be seen in the over-tempered specimens.
Martensitic structure completely disappeared in the specimens tempered at 600°C and thus, the wear coefficient increased.
Narasimhan, K.S: Materials Chemistry and Physics, Vol.67 (2001), p.56
Online since: June 2012
Authors: Li Yun Pan, Shun Bo Zhao, Hua Xiao Chen
Introduction
The carbonization of concrete is one of the key factors influencing the durability of concrete structures, which could result in the degradation of concrete protecting steel reinforcements from corrosion and bring the concrete into brittle in some extent [1].
Qu: Durability of Concrete Structures (Shanghai Press of Science and Technology, Shanghai, 2003)
Zhao: Design Principles of Concrete Structures (Tongji University Press, Shanghai, 2004)
Niu: Durability and Service Life Prediction of Concrete Structures (Science Press, Beijing, 2003)
Smolczy: Proceedings of 5th International Symposium on Chemistry of Cement, Tokyo, Vol. 3 (1986), p343-368
Qu: Durability of Concrete Structures (Shanghai Press of Science and Technology, Shanghai, 2003)
Zhao: Design Principles of Concrete Structures (Tongji University Press, Shanghai, 2004)
Niu: Durability and Service Life Prediction of Concrete Structures (Science Press, Beijing, 2003)
Smolczy: Proceedings of 5th International Symposium on Chemistry of Cement, Tokyo, Vol. 3 (1986), p343-368
Online since: May 2011
Authors: Yan Kong, Yuan Yang, Ying Jie Zhang, Sha Li
Results and discussion
Structure and composition of catalysts.
The mesoporous structures of the catalysts were confirmed by the strong diffraction peaks at about 2θ=2°in the XRD patterns, the typical type Ⅳ isotherms and the HRTEM images [7].
This result demonstrated that high copper content was essential for these mesoporous structure catalysts in NO reduction by CO.
In fact, XRD spectra of the reacted catalysts indicated that the mesoporous structures were still maintained.
The catalytic activity didn’t decrease until the hexagonal structure collapsed, which also indicated that the atoms of copper in the framework were the active species.
The mesoporous structures of the catalysts were confirmed by the strong diffraction peaks at about 2θ=2°in the XRD patterns, the typical type Ⅳ isotherms and the HRTEM images [7].
This result demonstrated that high copper content was essential for these mesoporous structure catalysts in NO reduction by CO.
In fact, XRD spectra of the reacted catalysts indicated that the mesoporous structures were still maintained.
The catalytic activity didn’t decrease until the hexagonal structure collapsed, which also indicated that the atoms of copper in the framework were the active species.