Using mean-field theory, we have studied the effect of quantum transverse anisotropies with RKKY interaction on the multi-layer transition and magnetic properties of the spin-1 Blume-Capel model of a system formed by ...Using mean-field theory, we have studied the effect of quantum transverse anisotropies with RKKY interaction on the multi-layer transition and magnetic properties of the spin-1 Blume-Capel model of a system formed by two magnetic multi-layer materials, of different thicknesses, separated by a non-magnetic spacer of thickness M. It is found that the multilayer magnetic order-disorder transition temperature depends strongly on the value of the transverse anisotropy. The multilayer transition temperature decreases when increasing the transverse anisotropy. Furthermore, there exists a critical quantum transverse anisotropy △xL beyond which the separate transitions occur in the two magnetic layers. The critical transverse anisotropy AxL decreases （increases） on increasing the non-magnetic spacer of thickness M （on increasing the crystal field）, and AxL undergoes oscillations as a function of the Fermi level.展开更多
The container loading problem (CLP) is a well-known NP-hard problem. Due to the computation complexity, heuristics is an often-sought approach. This article proposes two heuristics to pack homogeneous rectangular boxe...The container loading problem (CLP) is a well-known NP-hard problem. Due to the computation complexity, heuristics is an often-sought approach. This article proposes two heuristics to pack homogeneous rectangular boxes into a single container. Both algorithms adopt the concept of building layers on one face of the container, but the first heuristic determines the layer face once for all, while the second treats the remaining container space as a reduced-sized container after one layer is loaded and, hence, selects the layer face dynamically. To handle the layout design problem at a layer's level, a block-based 2D packing procedure is also developed. Numerical studies demonstrate the efficiency of the heuristics.展开更多
In this paper, the effects of thickness of AlN nucleation layer grown at high temperature on AlN epi-layer crystalline quality are investigated. Crack-ftee AlN samples with various nucleation thicknesses are grown on ...In this paper, the effects of thickness of AlN nucleation layer grown at high temperature on AlN epi-layer crystalline quality are investigated. Crack-ftee AlN samples with various nucleation thicknesses are grown on sapphire substrates by plasma-assisted molecular beam epitaxy. The AlN crystalline quality is analysed by transmission electron microscope and x-ray diffraction （XRD） rocking curves in both （002） and （102） planes. The surface profiles of nucleation layer with different thicknesses after in-situ annealing are also analysed by atomic force microscope. A critical nucleation thickness for realising high quality AlN films is found. When the nucleation thickness is above a certain value, the （102） XRD full width at half maximum （FWHM） of AlN bulk increases with nucleation thickness increasing, whereas the （002） XRD FWHM shows an opposite trend. These phenomena can be attributed to the characteristics of nucleation islands and the evolution of crystal grains during AlN main layer growth.展开更多
An improved 4H-SiC metal-semiconductor field-effect transistors （MESFETs） with step p-buffer layer is proposed, and the static and dynamic electrical performances are analysed in this paper. A step p-buffer layer ha...An improved 4H-SiC metal-semiconductor field-effect transistors （MESFETs） with step p-buffer layer is proposed, and the static and dynamic electrical performances are analysed in this paper. A step p-buffer layer has been applied not only to increase the channel current, but also to improve the transconductance. This is due to the fact that the variation in p-buffer layer depth leads to the decrease in parasitic series resistance resulting from the change in the active channel thickness and modulation in the electric field distribution inside the channel. Detailed numerical simulations demonstrate that the saturation drain current and the maximum theoretical output power density of the proposed structure are about 30% and 37% larger than those of the conventional structure. The cut-off frequency and the maximum oscillation frequency of the proposed MESFETs are 14.5 and 62 GHz, respectively, which are higher than that of the conventional structure. Therefore, the 4H-SiC MESFETs with step p-buffer layer have superior direct-current and radio-frequency performances compared to the similar devices based on the conventional structure.展开更多
Possible anti-mutagenic effects of eighnatural foods (sesame、chestnut、dad-lily、laver、red date、bamboo shoot、kelp、greentea) on Salmonella typhimurium TA98 and TA100mutants were tested.The tested
The present study solves a two-layer atmospheric wave equation model with a lower atmosphere concave wind profile and cold-air outbreak over sea, while simultaneously proving that such a wind shear may cause neutral b...The present study solves a two-layer atmospheric wave equation model with a lower atmosphere concave wind profile and cold-air outbreak over sea, while simultaneously proving that such a wind shear may cause neutral boundary layer roll vortices in the presence of disturbing sources upstream. Without thermal effects, the wind shear-induced waves have band structures at the top of the boundary layer that are similar to cloud street patterns observed over sea. This study proves that dynamic and thermal effects can act independently to initiate the roll vortices in the lower atmosphere. At the same time, a quantitative comparison shows that dynamic effects play a large role in the formation of roll vortices in the initial stage of cold-air outbreak and will be surpassed by thermal effects soon after surface heating commences.展开更多
In this study,a novel absorpent(MSAR600℃)with a hydrophobic surface and hierarchical porous structure for the removal of kitchen oil was facilely fabricated from the macroalgae,laver(Porphyra haitanensis)by incorpor-...In this study,a novel absorpent(MSAR600℃)with a hydrophobic surface and hierarchical porous structure for the removal of kitchen oil was facilely fabricated from the macroalgae,laver(Porphyra haitanensis)by incorpor-ating high-temperature carbonization and alkyl polyglucosides(APG)and rhamnolipid(RL)surfactants modifi-cation.The characterization results showed MSAR600℃ possessed a louts-leaf-like papillae microstructure with high contact angle(137.5°),abundant porous structure with high specific surface area(23.4 m^(2)/g),and various oxygen-containing functional groups(-OH,C=O,C-O).Batch adsorption experiments were conducted to inves-tigate the effect of adsorption time,temperature,pH,and absorbent dose on kitchen oil adsorption performance.Then the practical application for the removal of kitchen oil using MSAR600℃ was also performed.The results showed that MSAR600℃ had a higher removal efficiency for kitchen oil(75.98%),compared with the commercial detergent(72.3%).This study demonstrates an example of fabricating a green tableware detergent for enhanced removal performance of kitchen oil.展开更多
The spatial distribution of the energy flux, bottom boundary layer （BBL） energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examin...The spatial distribution of the energy flux, bottom boundary layer （BBL） energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examined in detail. These distributions are obtained from the results of a three-dimensional numerical simulation model （POM）. Compared with observation data from seven stations, the root mean square errors of tidal height are 2.6 cm and 1.2 cm for M2 and N2 respectively, and those of phase-lag are 21.8~ and 15.8~ respectively. The majority of the tidal energy flux off the deep basin is along the shelf edge, although some of this flux crosses the shelf edge, especially in the southeast of the shelf break. The total M2 energy dissipation in the Bering Sea is 30.43 GW, which is about 10 times of that of N2 and $2. The semidiurnal tidal energy enters mainly to the Bering Sea by Samalga Pass, Amukta Pass and Seguam Pass, accounting more than 60% of the total energy entering the Being Sea from the Pacific.展开更多
In this paper,the authors have summarized the kinematic and dynamic features of seismic waves observed by downhole seismometers in China.The features of seismic waves recorded on ground and downhole as well as in soil...In this paper,the authors have summarized the kinematic and dynamic features of seismic waves observed by downhole seismometers in China.The features of seismic waves recorded on ground and downhole as well as in soil layer and bedrock layer,including amplitude,traveltime,spectrum and wave field are discussed individually and then explained integrally in term of the effects of soft covering layer.This research result has been applied to the establishment of downhole seismic stations,the location of fractures in oil fields and the measurement of seismic focus parameters and structural parameters of media.展开更多
[ Objective] The study aimed to analyze and predict the suitable period of laver along the coastal areas of Jiangsu Province. [ Method ] TO enhance the ability of meteorology to service laver culture, using the modern...[ Objective] The study aimed to analyze and predict the suitable period of laver along the coastal areas of Jiangsu Province. [ Method ] TO enhance the ability of meteorology to service laver culture, using the modern weather forecast technology, agricultural weather prediction was de- veloped according to the demands for meteorological conditions during laver production. [ Result] From south to north, there were certain differ- ences in the suitable periods of laver culture, breeding and harvesting, with slight variations. The forecast of the first and last days of certain water temperature could provide scientific references for the meteorological service of laver culture, and the service effect became better after it was modi- fied with the aid of the medium-term and long-term weather prediction. [ Conclusion] The research can offer theoretical bases for the culture of laver along the coastal areas of Jiangsu Province.展开更多
A. W. Skempton cognized that shear strength of clay subjected to large shear deformation will be decreased because of development of orientation in the clay. N. R. Morgenstern and J. S. Tchalenko studied the microstru...A. W. Skempton cognized that shear strength of clay subjected to large shear deformation will be decreased because of development of orientation in the clay. N. R. Morgenstern and J. S. Tchalenko studied the microstructure orientation in the shear zone on slips with a polariscope and indicated that the thicknesses of the observed shear zone展开更多
We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results i...We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results indicate that the magnetron-sputtered HfTaON films on Si substrate are not stable during the post-deposition annealing （PDA）. HfTaON will react with Si and form the interfacial layer at the interface between HfTaON and Si substrate. Hf-N bonds are not stale at high temperature and easily replaced by oxygen, resulting in significant loss of nitrogen from the bulk film. SiO2 buffer layer introduction at the interface of HfraON and Si substrate may effectively suppress their reaction and control the formation of thicker interfacial layer. But SiO2 is a low k gate dielectric and too thicker SiO2 buffer layer will increase the gate dielectric＇s equivalent oxide thickness. SiON prepared by oxidation of N-implanted Si substrate has thinner physical thickness than SiO2 and is helpful to reduce the gate dielectric＇s equivalent oxide thickness.展开更多
文摘Using mean-field theory, we have studied the effect of quantum transverse anisotropies with RKKY interaction on the multi-layer transition and magnetic properties of the spin-1 Blume-Capel model of a system formed by two magnetic multi-layer materials, of different thicknesses, separated by a non-magnetic spacer of thickness M. It is found that the multilayer magnetic order-disorder transition temperature depends strongly on the value of the transverse anisotropy. The multilayer transition temperature decreases when increasing the transverse anisotropy. Furthermore, there exists a critical quantum transverse anisotropy △xL beyond which the separate transitions occur in the two magnetic layers. The critical transverse anisotropy AxL decreases （increases） on increasing the non-magnetic spacer of thickness M （on increasing the crystal field）, and AxL undergoes oscillations as a function of the Fermi level.
基金the Natural Sciences and Engineering Research Council of Canada (NSERC) under the Discovery Grant Program
文摘The container loading problem (CLP) is a well-known NP-hard problem. Due to the computation complexity, heuristics is an often-sought approach. This article proposes two heuristics to pack homogeneous rectangular boxes into a single container. Both algorithms adopt the concept of building layers on one face of the container, but the first heuristic determines the layer face once for all, while the second treats the remaining container space as a reduced-sized container after one layer is loaded and, hence, selects the layer face dynamically. To handle the layout design problem at a layer's level, a block-based 2D packing procedure is also developed. Numerical studies demonstrate the efficiency of the heuristics.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60536020 and 60723002)the National Basic Research Program of China (Grant Nos. 2006CB302800 and 2006CB921106)+1 种基金the National High Technology Research and Development Program for Advanced Materials of China (Grant No. 2006AA03A105)the Major Project of Beijing Municipal Science and Technology Commission,China (Grant No. D0404003040321)
文摘In this paper, the effects of thickness of AlN nucleation layer grown at high temperature on AlN epi-layer crystalline quality are investigated. Crack-ftee AlN samples with various nucleation thicknesses are grown on sapphire substrates by plasma-assisted molecular beam epitaxy. The AlN crystalline quality is analysed by transmission electron microscope and x-ray diffraction （XRD） rocking curves in both （002） and （102） planes. The surface profiles of nucleation layer with different thicknesses after in-situ annealing are also analysed by atomic force microscope. A critical nucleation thickness for realising high quality AlN films is found. When the nucleation thickness is above a certain value, the （102） XRD full width at half maximum （FWHM） of AlN bulk increases with nucleation thickness increasing, whereas the （002） XRD FWHM shows an opposite trend. These phenomena can be attributed to the characteristics of nucleation islands and the evolution of crystal grains during AlN main layer growth.
基金Project supported by the Fundamental Research Funds for the Central Universities(Grant No.ZYGX2009J029)
文摘An improved 4H-SiC metal-semiconductor field-effect transistors （MESFETs） with step p-buffer layer is proposed, and the static and dynamic electrical performances are analysed in this paper. A step p-buffer layer has been applied not only to increase the channel current, but also to improve the transconductance. This is due to the fact that the variation in p-buffer layer depth leads to the decrease in parasitic series resistance resulting from the change in the active channel thickness and modulation in the electric field distribution inside the channel. Detailed numerical simulations demonstrate that the saturation drain current and the maximum theoretical output power density of the proposed structure are about 30% and 37% larger than those of the conventional structure. The cut-off frequency and the maximum oscillation frequency of the proposed MESFETs are 14.5 and 62 GHz, respectively, which are higher than that of the conventional structure. Therefore, the 4H-SiC MESFETs with step p-buffer layer have superior direct-current and radio-frequency performances compared to the similar devices based on the conventional structure.
文摘Possible anti-mutagenic effects of eighnatural foods (sesame、chestnut、dad-lily、laver、red date、bamboo shoot、kelp、greentea) on Salmonella typhimurium TA98 and TA100mutants were tested.The tested
基金supported by the National Basic Research Program of China (973 Program) (Grant No. 2010CB951801)the National Natural Science Foundation of China (Key Program) (Grant No. 41030106)
文摘The present study solves a two-layer atmospheric wave equation model with a lower atmosphere concave wind profile and cold-air outbreak over sea, while simultaneously proving that such a wind shear may cause neutral boundary layer roll vortices in the presence of disturbing sources upstream. Without thermal effects, the wind shear-induced waves have band structures at the top of the boundary layer that are similar to cloud street patterns observed over sea. This study proves that dynamic and thermal effects can act independently to initiate the roll vortices in the lower atmosphere. At the same time, a quantitative comparison shows that dynamic effects play a large role in the formation of roll vortices in the initial stage of cold-air outbreak and will be surpassed by thermal effects soon after surface heating commences.
基金This study was supported by the Fundamental Research Funds for Zhejiang Provincial Universities and Research Institutes(No.2021J004)the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202044721).
文摘In this study,a novel absorpent(MSAR600℃)with a hydrophobic surface and hierarchical porous structure for the removal of kitchen oil was facilely fabricated from the macroalgae,laver(Porphyra haitanensis)by incorpor-ating high-temperature carbonization and alkyl polyglucosides(APG)and rhamnolipid(RL)surfactants modifi-cation.The characterization results showed MSAR600℃ possessed a louts-leaf-like papillae microstructure with high contact angle(137.5°),abundant porous structure with high specific surface area(23.4 m^(2)/g),and various oxygen-containing functional groups(-OH,C=O,C-O).Batch adsorption experiments were conducted to inves-tigate the effect of adsorption time,temperature,pH,and absorbent dose on kitchen oil adsorption performance.Then the practical application for the removal of kitchen oil using MSAR600℃ was also performed.The results showed that MSAR600℃ had a higher removal efficiency for kitchen oil(75.98%),compared with the commercial detergent(72.3%).This study demonstrates an example of fabricating a green tableware detergent for enhanced removal performance of kitchen oil.
基金Supported by the Outstanding Middle-aged and Young Scientist Foundation in Shandong Province under Grant of No.2008BS06003National High Technology Research and development Program (863 Program) (No.2007AA06A403)National Nature Science Foundation under Grant of No.40706008
文摘The spatial distribution of the energy flux, bottom boundary layer （BBL） energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examined in detail. These distributions are obtained from the results of a three-dimensional numerical simulation model （POM）. Compared with observation data from seven stations, the root mean square errors of tidal height are 2.6 cm and 1.2 cm for M2 and N2 respectively, and those of phase-lag are 21.8~ and 15.8~ respectively. The majority of the tidal energy flux off the deep basin is along the shelf edge, although some of this flux crosses the shelf edge, especially in the southeast of the shelf break. The total M2 energy dissipation in the Bering Sea is 30.43 GW, which is about 10 times of that of N2 and $2. The semidiurnal tidal energy enters mainly to the Bering Sea by Samalga Pass, Amukta Pass and Seguam Pass, accounting more than 60% of the total energy entering the Being Sea from the Pacific.
文摘In this paper,the authors have summarized the kinematic and dynamic features of seismic waves observed by downhole seismometers in China.The features of seismic waves recorded on ground and downhole as well as in soil layer and bedrock layer,including amplitude,traveltime,spectrum and wave field are discussed individually and then explained integrally in term of the effects of soft covering layer.This research result has been applied to the establishment of downhole seismic stations,the location of fractures in oil fields and the measurement of seismic focus parameters and structural parameters of media.
基金Supported by National Research Fund for Public Welfare (Meteorology) of China (GYHY201006029)Meteorological Scientific Research Open Fund of Jiangsu Province,China (ZD201108)
文摘[ Objective] The study aimed to analyze and predict the suitable period of laver along the coastal areas of Jiangsu Province. [ Method ] TO enhance the ability of meteorology to service laver culture, using the modern weather forecast technology, agricultural weather prediction was de- veloped according to the demands for meteorological conditions during laver production. [ Result] From south to north, there were certain differ- ences in the suitable periods of laver culture, breeding and harvesting, with slight variations. The forecast of the first and last days of certain water temperature could provide scientific references for the meteorological service of laver culture, and the service effect became better after it was modi- fied with the aid of the medium-term and long-term weather prediction. [ Conclusion] The research can offer theoretical bases for the culture of laver along the coastal areas of Jiangsu Province.
文摘A. W. Skempton cognized that shear strength of clay subjected to large shear deformation will be decreased because of development of orientation in the clay. N. R. Morgenstern and J. S. Tchalenko studied the microstructure orientation in the shear zone on slips with a polariscope and indicated that the thicknesses of the observed shear zone
基金supported by the State Key Development Program for Basic Research of China (No. 2006CB302704) the National Natural Science Foundation of China (No. 60776030)
文摘We investigate the thermal stability of HfTaON films prepared by physical vapor deposition using high resolution transmission electronic microscope （HRTEM） and X-ray photoelectron spectroscopy （XPS）. The results indicate that the magnetron-sputtered HfTaON films on Si substrate are not stable during the post-deposition annealing （PDA）. HfTaON will react with Si and form the interfacial layer at the interface between HfTaON and Si substrate. Hf-N bonds are not stale at high temperature and easily replaced by oxygen, resulting in significant loss of nitrogen from the bulk film. SiO2 buffer layer introduction at the interface of HfraON and Si substrate may effectively suppress their reaction and control the formation of thicker interfacial layer. But SiO2 is a low k gate dielectric and too thicker SiO2 buffer layer will increase the gate dielectric＇s equivalent oxide thickness. SiON prepared by oxidation of N-implanted Si substrate has thinner physical thickness than SiO2 and is helpful to reduce the gate dielectric＇s equivalent oxide thickness.
