Dear authors and readers,As the quality of our journal becomes better and better and standardized,we received a lot of papers submitted to our journal,the work load for the editorial office is much more than before,an...Dear authors and readers,As the quality of our journal becomes better and better and standardized,we received a lot of papers submitted to our journal,the work load for the editorial office is much more than before,and we have to increase our co-workers in edi-torial office,and we also changed our work flow path,we asked the professional contingent to composing and typeset-ting the papers,so the expenses of the journal increased.Refer to other journals,start from July 2009 the authors展开更多
Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN, XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russ...Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN, XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russia LEFEBVRE, A.H. U.S.A. LEONTIEV, A.I. Russia MA, Chong-Fang China MA,TongZe China MARTYNENKO, O.G. Belorussia NAKORIAKOV, V.E. Russia RAUTENBERG, Manfred Germany SWITHENBANK, J. United Kingdom WANG,BuXuan China WENG, Shi Lie China WU, Cheng Kang China YE, Da Jun China ZIEREP, Jurgen展开更多
Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications i...Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications in the field of thermal and fluid sciences. The journal publishes high-quality papers of original work on experimental, numerical and theoretical investigations which give better insight into the major areas of thermal and fluid sciences. The scope of the Journal covers the following aspects:展开更多
Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications i...Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications in the field of thermal and fluid sciences. The journal publishes high-quality papers of original work on experimental, numerical and theoretical investigations which give better insight into the major areas of thermal and fluid sciences. The scope of the Journal covers the following aspects:展开更多
A novel piezoelectricity based nano energy conversion device using vertically aligned ZnO nanowires/PVVH matrix as the working unit is proposed. Thermal energy is converted to electricity via the interaction of the PV...A novel piezoelectricity based nano energy conversion device using vertically aligned ZnO nanowires/PVVH matrix as the working unit is proposed. Thermal energy is converted to electricity via the interaction of the PVVH polymer and ZnO nanowires. The thermal properties of PVVH ave studied using Raman spectroscopy under different temperatures. The results show that the structure of PVVH is sensitive to fluctuations of the environmental temperatures. With the increasing temperature, PVVH tends to be crystallized and stress can be developed inside the polymer. The stress is responsible for the deformation and voltage generation of the ZnO nanowires.展开更多
We prepare the gallium oxide （β-Ga2O3） nanomaterials from gallium and oxygen by thermal evaporation in the argon atmosphere and research their oxygen sensing under UV illumination with different oxygen pressures. X...We prepare the gallium oxide （β-Ga2O3） nanomaterials from gallium and oxygen by thermal evaporation in the argon atmosphere and research their oxygen sensing under UV illumination with different oxygen pressures. X-ray diffraction reveals that the synthesized product is monoclinic gallium oxide, it is further confirmed by electron diffraction of transmission electron microscope, and its morphology through the observation using scanning electron microscope reveals thatβ-Ga2O3 nanobelts with a breadth less than lOOnm and length of severai micrometers are synthesized under low oxygen pressure, while the nano/microbelts are synthesized under high oxygen pressure. Room-temperature oxygen sensing is tested under at 254 nm illumination and it is found that the current decreases quickly first and then slowly with oxygen pressure from low to high.展开更多
The melt＇s solidification behavior of elemental selenium is investigated by a series of experiments including rapid compressing to 2.8 and 3.5 GPa within 20ms respectively, slow compressing to 2.8 GPa for 20 min and ...The melt＇s solidification behavior of elemental selenium is investigated by a series of experiments including rapid compressing to 2.8 and 3.5 GPa within 20ms respectively, slow compressing to 2.8 GPa for 20 min and natural cooling at ambient pressure. Based on the x-ray diffraction, scanning electron microscope and transmission electron microscope results of the recovered samples, it is clearly shown that homogenous nanostructures are formed only by the rapid compression processes, and that the average crystal sizes are about 18.7 and 19.0 nm in the samples recovered from 2.8 and 3.5 GPa, respectively. The relative density of the nanocrystalline bulk reaches 98.17% of the theoretical value. It is suggested that rapid compression could induce pervasive nucleation and restrain grain growth during the solidification, which is related to fast supercooling, higher viscosity of the melt and lower diffusivity of atoms under high pressure.展开更多
Magnetic composites of carbon nanotubes （CNTs） are synthesized by the in situ catalytic decomposition of benzene at temperatures as low as 400℃ over Fe nanoparticles （mean grain size = 26 nm） produced by sol-gel ...Magnetic composites of carbon nanotubes （CNTs） are synthesized by the in situ catalytic decomposition of benzene at temperatures as low as 400℃ over Fe nanoparticles （mean grain size = 26 nm） produced by sol-gel fabrication and hydrogen reduction. The yield of CNT composite is up to about 3025% in a run of 6 h. FE- SEM and HRTEM investigations reveal that one-dimensional carbon species are produced in a large quantity. A relatively high value of magnetization is observed for the composite due to the encapsulation of ferromagnetic Fe3 C and/or α-Fe. The method is suitable for the mass-production of CNT composites that contain magnetic nanoparticles.展开更多
The microstructural variation near surface of nano elastic materials is analyzed based on different potentials. The atomic/molecular mechanism underlying the variation and its effect on elastic modulus are such that t...The microstructural variation near surface of nano elastic materials is analyzed based on different potentials. The atomic/molecular mechanism underlying the variation and its effect on elastic modulus are such that the nature of long-range interactions （attractive or repulsive） in the atomic/molecular potentials essentially governs the variation near surface （looser or tighter） and results in two opposite size effects （decreasing or increasing modulus） with decreasing size.展开更多
We investigate a peculiar phenomenon by processing ZnO nanobelts with an atomic force microscope （AFM）. In the contact mode of AFM, peculiar bending occurs in meso-scale when the nanobelt is applied with force in la...We investigate a peculiar phenomenon by processing ZnO nanobelts with an atomic force microscope （AFM）. In the contact mode of AFM, peculiar bending occurs in meso-scale when the nanobelt is applied with force in lateral direction. We study the mechanical properties of ZnO nanobelts under the influence of small size effect, with finite element analysis and mathematical analysis by means of Matlab. Based on this abnormal effect, a novel measuring method is proposed, which allows the surface morphology and surface properties to be characterized at the same time.展开更多
Pure zinc blende GaAs nanowires were grown by metal organic chemical vapor deposition on GaAs（111）B substrates via Au catalyzed vapor-liquid-solid mechanism. The diameter, size distribution, and density of Au partic...Pure zinc blende GaAs nanowires were grown by metal organic chemical vapor deposition on GaAs（111）B substrates via Au catalyzed vapor-liquid-solid mechanism. The diameter, size distribution, and density of Au particles can be changed by varying the Au film thickness. We find that the grown nanowires are of rod-like shapes and pure zinc blende structure; moreover, the growth rate depends on the density of Au particles and it is independent of its diameters. It can be concluded that the nanowire was grown with main contributions from the direct impingement of vapor species onto the Au-Ga droplets and contributions from adatom diffusion can be negligible. The results indicate that the droplet acts as a catalyst rather than an adatom collector.展开更多
We report new Raman features of epitaxial graphene （EG） on Si-face 4H-SiC prepared by pulsed electron irradiation （PEI）. With increasing graphene layers, frequencies of G and 2D peaks show blue-shifts and approach...We report new Raman features of epitaxial graphene （EG） on Si-face 4H-SiC prepared by pulsed electron irradiation （PEI）. With increasing graphene layers, frequencies of G and 2D peaks show blue-shifts and approach those of bulk highly-oriented pyrolytic graphite. It is indicated that the EG is slightly tension strained and tends to be strain-free. Meanwhile, single Lorentzian line shapes are well fitted to the 2D peaks of EG on SiC（O001） and their full widths at half maximum decrease with the increasing graphene layers, which indicates that the multilayer EG on Si-face can also contain turbostratic stacking by our PEI route instead of only AB Bernal stacking by a traditional thermal annealing method. It is worth noting that the stacking style plays an important role on the charge carrier mobility. Therefore our findings will be a candidate for growing quality graphene with high carrier mobility both on the Si- and C-terminated SiC substrate. Mechanisms behind the features are studied and discussed.展开更多
The effect of In composition on two-dimensional electron gas in wurtzite AlGaN/InGaN heterostructures is theoretically investigated. The sheet carrier density is shown to increase nearly linearly with In mole fraction...The effect of In composition on two-dimensional electron gas in wurtzite AlGaN/InGaN heterostructures is theoretically investigated. The sheet carrier density is shown to increase nearly linearly with In mole fraction x, due to the increase in the polarization charge at the AlGaN/InGaN interface. The electron sheet density is enhanced with the doping in the AlGaN layer. The sheet carrier density is as high as 3.7×1013 cm^-2 at the donor density of 10×1018 cm^-3 for the HEMT structure with x=0.3. The contribution of additional donor density on the electron sheet density is nearly independent of the In mole fraction.展开更多
High pressure behavior of sodium titanate nanotubes （Na2Ti2O5） is investigated by Raman spectroscopy in a diamond anvil cell （DAC） at room temperature. The two pressure-induced irreversible phase transitions are o...High pressure behavior of sodium titanate nanotubes （Na2Ti2O5） is investigated by Raman spectroscopy in a diamond anvil cell （DAC） at room temperature. The two pressure-induced irreversible phase transitions are observed under the given pressure. One occurs at about 4.2 GPa accompanied with a new Raman peak emerging at 834 cm-1 which results from the lattice distortion of the Ti-O network in titanate nanotubes. It can be can be assigned to Ti-O lattice vibrations within lepidocrocite-type （H0.7Ti1.825V0.175O4＆#12539;H2O）TiO6 octahedral host layers with V being vacancy. The structure of the nanotubes transforms to orthorhombic lepidocrocite structure. Another amorphous phase transition occurs at 16.7 GPa. This phase transition is induced by the collapse of titanate nanotubes. All the Raman bands shift toward higher wavenumbers with a pressure dependence ranging from 1.58-5.6 cm-1/GPa.展开更多
Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN,XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russi...Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN,XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russia LEFEBVRE, A.H. U.S.A. LEONTIEV, A.I. Russia MA, Chong-Fang China MA, Tong Ze China MARTYNENKO, O.G. Belorussia NAKORIAKOV, V.E. Russia RAUTENBERG, Manfred Germany SWITHENBANK, J. United Kingdom WANG, Bu Xuan China WENG, Shi Lie China WU, Cheng Kang China YE, Da Jun China ZIEREP, Jurgen展开更多
Bending and first flexural mode vibration behavior of electrostatic actuated nanometer-sized interdigitated cantilever arrays are characterized under vacuum conditions. The pull-in＇＇ effect in dc driving and the har...Bending and first flexural mode vibration behavior of electrostatic actuated nanometer-sized interdigitated cantilever arrays are characterized under vacuum conditions. The pull-in＇＇ effect in dc driving and the hard spring effect＇＇ in ac driving are observed. A mass sensitivity of 20 fg is expected for our devices due to the ultra-small mass of the arm and relative high Q factor. The mass-spring lump model combined with Green＇s function method is used to fit the dc driving behaviors including the pull-in voltage. For the ac driving case, the polynomial expansion of the capacitive force is used in the model. The successfully fittings of the pull-in voltage and the hard spring effect prove that our simulation method could be used for guiding the geometrical design of cantilever-based sensors.展开更多
文摘Dear authors and readers,As the quality of our journal becomes better and better and standardized,we received a lot of papers submitted to our journal,the work load for the editorial office is much more than before,and we have to increase our co-workers in edi-torial office,and we also changed our work flow path,we asked the professional contingent to composing and typeset-ting the papers,so the expenses of the journal increased.Refer to other journals,start from July 2009 the authors
文摘Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN, XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russia LEFEBVRE, A.H. U.S.A. LEONTIEV, A.I. Russia MA, Chong-Fang China MA,TongZe China MARTYNENKO, O.G. Belorussia NAKORIAKOV, V.E. Russia RAUTENBERG, Manfred Germany SWITHENBANK, J. United Kingdom WANG,BuXuan China WENG, Shi Lie China WU, Cheng Kang China YE, Da Jun China ZIEREP, Jurgen
文摘Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications in the field of thermal and fluid sciences. The journal publishes high-quality papers of original work on experimental, numerical and theoretical investigations which give better insight into the major areas of thermal and fluid sciences. The scope of the Journal covers the following aspects:
文摘Journal of Thermal Science, a quarterly English language journal run by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, provides a worldwide forum for research and application communications in the field of thermal and fluid sciences. The journal publishes high-quality papers of original work on experimental, numerical and theoretical investigations which give better insight into the major areas of thermal and fluid sciences. The scope of the Journal covers the following aspects:
基金Supported by the National Natural Science Foundation of China under Grant No 51072119, the Science and Technology Commission of Shanghai Municipality under Grant Nos 09QA1404100 and 10231201103, the National Basic Research Program of China under Grant No 2010CB234609, and the Scientific Research Foundation for the Returned Overseas Chinese Scholars , State Education Ministry.
文摘A novel piezoelectricity based nano energy conversion device using vertically aligned ZnO nanowires/PVVH matrix as the working unit is proposed. Thermal energy is converted to electricity via the interaction of the PVVH polymer and ZnO nanowires. The thermal properties of PVVH ave studied using Raman spectroscopy under different temperatures. The results show that the structure of PVVH is sensitive to fluctuations of the environmental temperatures. With the increasing temperature, PVVH tends to be crystallized and stress can be developed inside the polymer. The stress is responsible for the deformation and voltage generation of the ZnO nanowires.
文摘We prepare the gallium oxide （β-Ga2O3） nanomaterials from gallium and oxygen by thermal evaporation in the argon atmosphere and research their oxygen sensing under UV illumination with different oxygen pressures. X-ray diffraction reveals that the synthesized product is monoclinic gallium oxide, it is further confirmed by electron diffraction of transmission electron microscope, and its morphology through the observation using scanning electron microscope reveals thatβ-Ga2O3 nanobelts with a breadth less than lOOnm and length of severai micrometers are synthesized under low oxygen pressure, while the nano/microbelts are synthesized under high oxygen pressure. Room-temperature oxygen sensing is tested under at 254 nm illumination and it is found that the current decreases quickly first and then slowly with oxygen pressure from low to high.
基金Supported by the National Natural Science Foundation of China under Grant No 10774123.
文摘The melt＇s solidification behavior of elemental selenium is investigated by a series of experiments including rapid compressing to 2.8 and 3.5 GPa within 20ms respectively, slow compressing to 2.8 GPa for 20 min and natural cooling at ambient pressure. Based on the x-ray diffraction, scanning electron microscope and transmission electron microscope results of the recovered samples, it is clearly shown that homogenous nanostructures are formed only by the rapid compression processes, and that the average crystal sizes are about 18.7 and 19.0 nm in the samples recovered from 2.8 and 3.5 GPa, respectively. The relative density of the nanocrystalline bulk reaches 98.17% of the theoretical value. It is suggested that rapid compression could induce pervasive nucleation and restrain grain growth during the solidification, which is related to fast supercooling, higher viscosity of the melt and lower diffusivity of atoms under high pressure.
基金Supported by the National Natural Science Foundation of China under Grant No 10674059, the National High Technology Research and Development Program of China under Grant No 2007AA021805, and the National Basic Research Program of China under Grant No 2005CB623605.
文摘Magnetic composites of carbon nanotubes （CNTs） are synthesized by the in situ catalytic decomposition of benzene at temperatures as low as 400℃ over Fe nanoparticles （mean grain size = 26 nm） produced by sol-gel fabrication and hydrogen reduction. The yield of CNT composite is up to about 3025% in a run of 6 h. FE- SEM and HRTEM investigations reveal that one-dimensional carbon species are produced in a large quantity. A relatively high value of magnetization is observed for the composite due to the encapsulation of ferromagnetic Fe3 C and/or α-Fe. The method is suitable for the mass-production of CNT composites that contain magnetic nanoparticles.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10721202, 10432050, 10772012 and 10732090, and the Knowledge Innovation Project of Chinese Academy of Sciences （KJCX2-YW-M04）.
文摘The microstructural variation near surface of nano elastic materials is analyzed based on different potentials. The atomic/molecular mechanism underlying the variation and its effect on elastic modulus are such that the nature of long-range interactions （attractive or repulsive） in the atomic/molecular potentials essentially governs the variation near surface （looser or tighter） and results in two opposite size effects （decreasing or increasing modulus） with decreasing size.
文摘We investigate a peculiar phenomenon by processing ZnO nanobelts with an atomic force microscope （AFM）. In the contact mode of AFM, peculiar bending occurs in meso-scale when the nanobelt is applied with force in lateral direction. We study the mechanical properties of ZnO nanobelts under the influence of small size effect, with finite element analysis and mathematical analysis by means of Matlab. Based on this abnormal effect, a novel measuring method is proposed, which allows the surface morphology and surface properties to be characterized at the same time.
文摘Pure zinc blende GaAs nanowires were grown by metal organic chemical vapor deposition on GaAs（111）B substrates via Au catalyzed vapor-liquid-solid mechanism. The diameter, size distribution, and density of Au particles can be changed by varying the Au film thickness. We find that the grown nanowires are of rod-like shapes and pure zinc blende structure; moreover, the growth rate depends on the density of Au particles and it is independent of its diameters. It can be concluded that the nanowire was grown with main contributions from the direct impingement of vapor species onto the Au-Ga droplets and contributions from adatom diffusion can be negligible. The results indicate that the droplet acts as a catalyst rather than an adatom collector.
基金Supported partly by the Knowledge Innovation Project of Chinese Academy of Sciences under Grant Nos KJCX2-YW-W22 and YYYJ-0701, the Ministry of Science and Technology of China under Grant Nos 2007BAE34B00, 2006AA03A146, 2007CB936300 and 2006AA03A107, the National Natural Science Foundation of China under Grant Nos 50972162 and 50702073, and Beijing Municipal Science and Technology Commission under Grant No D09080300500000.
文摘We report new Raman features of epitaxial graphene （EG） on Si-face 4H-SiC prepared by pulsed electron irradiation （PEI）. With increasing graphene layers, frequencies of G and 2D peaks show blue-shifts and approach those of bulk highly-oriented pyrolytic graphite. It is indicated that the EG is slightly tension strained and tends to be strain-free. Meanwhile, single Lorentzian line shapes are well fitted to the 2D peaks of EG on SiC（O001） and their full widths at half maximum decrease with the increasing graphene layers, which indicates that the multilayer EG on Si-face can also contain turbostratic stacking by our PEI route instead of only AB Bernal stacking by a traditional thermal annealing method. It is worth noting that the stacking style plays an important role on the charge carrier mobility. Therefore our findings will be a candidate for growing quality graphene with high carrier mobility both on the Si- and C-terminated SiC substrate. Mechanisms behind the features are studied and discussed.
文摘The effect of In composition on two-dimensional electron gas in wurtzite AlGaN/InGaN heterostructures is theoretically investigated. The sheet carrier density is shown to increase nearly linearly with In mole fraction x, due to the increase in the polarization charge at the AlGaN/InGaN interface. The electron sheet density is enhanced with the doping in the AlGaN layer. The sheet carrier density is as high as 3.7×1013 cm^-2 at the donor density of 10×1018 cm^-3 for the HEMT structure with x=0.3. The contribution of additional donor density on the electron sheet density is nearly independent of the In mole fraction.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50334030 and 100874040, the National Basic Research Program of China under Grant Nos 2005CB724400 and 2007CB616911, the International Science and Technology Cooperation Project of China under Grant No 2001CB711201, and the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China （No 708062）.
文摘High pressure behavior of sodium titanate nanotubes （Na2Ti2O5） is investigated by Raman spectroscopy in a diamond anvil cell （DAC） at room temperature. The two pressure-induced irreversible phase transitions are observed under the given pressure. One occurs at about 4.2 GPa accompanied with a new Raman peak emerging at 834 cm-1 which results from the lattice distortion of the Ti-O network in titanate nanotubes. It can be can be assigned to Ti-O lattice vibrations within lepidocrocite-type （H0.7Ti1.825V0.175O4＆#12539;H2O）TiO6 octahedral host layers with V being vacancy. The structure of the nanotubes transforms to orthorhombic lepidocrocite structure. Another amorphous phase transition occurs at 16.7 GPa. This phase transition is induced by the collapse of titanate nanotubes. All the Raman bands shift toward higher wavenumbers with a pressure dependence ranging from 1.58-5.6 cm-1/GPa.
文摘Editorial Advisory Board AUNG, Win U.S.A. BERGLES, Arthur E. U.S.A. CHEN,XueJun China DVORAK, Rudolf Czech GAL-OR, Ben Israel GALLUS, H.E. Germany GRUNDMANN, Roger Germany HUANG, Zhao Xiang China IVANOV, Michail Russia LEFEBVRE, A.H. U.S.A. LEONTIEV, A.I. Russia MA, Chong-Fang China MA, Tong Ze China MARTYNENKO, O.G. Belorussia NAKORIAKOV, V.E. Russia RAUTENBERG, Manfred Germany SWITHENBANK, J. United Kingdom WANG, Bu Xuan China WENG, Shi Lie China WU, Cheng Kang China YE, Da Jun China ZIEREP, Jurgen
文摘Bending and first flexural mode vibration behavior of electrostatic actuated nanometer-sized interdigitated cantilever arrays are characterized under vacuum conditions. The pull-in＇＇ effect in dc driving and the hard spring effect＇＇ in ac driving are observed. A mass sensitivity of 20 fg is expected for our devices due to the ultra-small mass of the arm and relative high Q factor. The mass-spring lump model combined with Green＇s function method is used to fit the dc driving behaviors including the pull-in voltage. For the ac driving case, the polynomial expansion of the capacitive force is used in the model. The successfully fittings of the pull-in voltage and the hard spring effect prove that our simulation method could be used for guiding the geometrical design of cantilever-based sensors.
