Studies of surface film medium on the sea surface are carried out in this paper for developing the technology to automatically detect and classify sea surface films, and an effective dielectric constant model of elect...Studies of surface film medium on the sea surface are carried out in this paper for developing the technology to automatically detect and classify sea surface films, and an effective dielectric constant model of electromagnetic backscattering from a stratified air–ocean interface. Numerical results of the new model show the characteristics of effective dielectric constants for the air–sea surface film–sea water medium as follows. The effective dielectric constants decrease with increasing relative dielectric constants of the sea surface films. The effective dielectric constants decrease in horizontal polarization(abbr. HH polarization) and increase in VV vertical polarization(abbr. VV polarization) with increasing radar incident angle. Effective dielectric constants vary with relative sea surface film thickness as a cosinusoidal function of sea surface film thickness. Effective dielectric constant of VV polarization is larger than that of HH polarization. Two potential applications are found with our model, i.e., the retrieval of dielectric constants from the sea surface film, and the film thickness retrieval with our model. Our model has a highly significant influence on improving the technology related to the remote sensing of sea surface films.展开更多
Interference layer metallography was used to identify the phases present in the aluminide coating on superalloy IN738LC. They are: two intermetallic aluminides NiAl and Ni_3Al, y-solid solution and a Cr-rich solid sol...Interference layer metallography was used to identify the phases present in the aluminide coating on superalloy IN738LC. They are: two intermetallic aluminides NiAl and Ni_3Al, y-solid solution and a Cr-rich solid solution, two sulphides M_(23)C_6 and MC, and two sulphides (Al,Cr)_3S_4 and (Cr,Ti)_3S_4. ZnS and ZnSe are proposed to be vapor deposited onto the surface of the specimen to get good colour contrast and good light-dark contrast. The refractive index and absorption coefficient of all these phases have been detemined.展开更多
To provide a safe transportation system in an extremely cold region,evaluation needs to be conducted of the thickness and the volumetric water content of the active layer,as they significantly affect frost heave.The o...To provide a safe transportation system in an extremely cold region,evaluation needs to be conducted of the thickness and the volumetric water content of the active layer,as they significantly affect frost heave.The objective of this study was to evaluate the dielectric constant(κ)of the active layer using ground-penetrating radar(GPR)and a dynamic cone penetrometer(DCP);this evaluation was then used to estimate the thickness and the volumetric water content of the active layer.A field located in midwest Alaska was selected as the study site.A GPR survey and two DCP tests were conducted on the surface of the ground,and the ground temperature was measured.From the GPR survey,travel times of the electromagnetic wave in the active layer were obtained.In addition,the thickness of the active layer was determined by using the dynamic cone penetration index(DCPI)and ground temperature.By using the travel time and travel distance of the electromagnetic wave in the active layer,dielectric constants were calculated as 26.3 and 26.4 for two DCP points.From the mean dielectric constant,the volumetric water content was estimated to be 40%~43%,and the thickness of the active layer was evaluated along the GPR survey line.The spatial-scaled GPR image showed that the thickness of the active layer varied from 520 mm to 700 mm due to the presence of a puddle,which accelerated the heat exchange.The results show that evaluation of the dielectric constant using the GPR survey and the DCP test can be effectively used to estimate the thickness and the volumetric water content of the active layer.展开更多
H_2O-based and O_3-based La_xAl_yO nanolaminate films were deposited on Si substrates by atomic layer deposition(ALD). Structures and performances of the films were changed by different barrier layers. The effects o...H_2O-based and O_3-based La_xAl_yO nanolaminate films were deposited on Si substrates by atomic layer deposition(ALD). Structures and performances of the films were changed by different barrier layers. The effects of different structures on the electrical characteristics and physical properties of the La_xAl_yO films were studied. Chemical bonds in the La_xAl_yO films grown with different structures and different oxidants were also investigated with x-ray photoelectron spectroscopy(XPS). The preliminary testing results indicate that the La_xAl_yO films with different structures and different oxidants show different characteristics, including dielectric constant, equivalent oxide thickness(EOT), electrical properties, and stability.展开更多
In this study, we investigate the effects of Ga N cap layer thickness on the two-dimensional electron gas(2DEG)electron density and 2DEG electron mobility of Al N/Ga N heterostructures by using the temperature-depen...In this study, we investigate the effects of Ga N cap layer thickness on the two-dimensional electron gas(2DEG)electron density and 2DEG electron mobility of Al N/Ga N heterostructures by using the temperature-dependent Hall measurement and theoretical fitting method. The results of our analysis clearly indicate that the Ga N cap layer thickness of an Al N/Ga N heterostructure has influences on the 2DEG electron density and the electron mobility. For the Al N/Ga N heterostructures with a 3-nm Al N barrier layer, the optimized thickness of the Ga N cap layer is around 4 nm and the strained a-axis lattice constant of the Al N barrier layer is less than that of Ga N.展开更多
This paper focuses on the design of the cross layer between the video application layer and the MIMO physical layer. MIMO physical layer research has promised an enormous increase in the capacity of wireless communica...This paper focuses on the design of the cross layer between the video application layer and the MIMO physical layer. MIMO physical layer research has promised an enormous increase in the capacity of wireless communication systems. Also MIMO wireless systems operate under fading conditions where the channel faces arbitrary fluctuations. Since the wireless channel changes over each coherence period, the capacity of the wireless channel, given the power constraints, changes. Hence to make efficient use of the available capacity one needs to adapt the video bit rate. However it is impossible to adapt at the application layer as changing the parameters of the video takes more time than the coherence period of the channel. In this paper we address this problem through a novel solution and also investigate its performance through a simulation study.展开更多
A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography pl...A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography plates as a spray reagent. This new reagent enabled to produce various distinguishable colors with amino acids with different RF values. The detection limits and the binding ability of PDBIQ with amino acids have been calculated. PDBIQ is also able to detect aminoacids from hydrolised seed protein. The title compound also exhibited profound inhibitory action against some gm (+ve) and gm (-ve) bacterial organisms. This paper deals with synthesis, spectroscopic application and biological evaluation of the organic moity.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFC1401007)the Global Change Research Program of China(Grant No.2015CB953901)+2 种基金the Canadian Program on Energy Research and Development(OERD)the Office of Naval Research(Code 322,“Arctic and Global Prediction”(Principal Investigator:William Perrie))(Grant No.N00014-15-1-2611)the National Natural Science Foundation of China(Grant No.41276187)
文摘Studies of surface film medium on the sea surface are carried out in this paper for developing the technology to automatically detect and classify sea surface films, and an effective dielectric constant model of electromagnetic backscattering from a stratified air–ocean interface. Numerical results of the new model show the characteristics of effective dielectric constants for the air–sea surface film–sea water medium as follows. The effective dielectric constants decrease with increasing relative dielectric constants of the sea surface films. The effective dielectric constants decrease in horizontal polarization(abbr. HH polarization) and increase in VV vertical polarization(abbr. VV polarization) with increasing radar incident angle. Effective dielectric constants vary with relative sea surface film thickness as a cosinusoidal function of sea surface film thickness. Effective dielectric constant of VV polarization is larger than that of HH polarization. Two potential applications are found with our model, i.e., the retrieval of dielectric constants from the sea surface film, and the film thickness retrieval with our model. Our model has a highly significant influence on improving the technology related to the remote sensing of sea surface films.
文摘Interference layer metallography was used to identify the phases present in the aluminide coating on superalloy IN738LC. They are: two intermetallic aluminides NiAl and Ni_3Al, y-solid solution and a Cr-rich solid solution, two sulphides M_(23)C_6 and MC, and two sulphides (Al,Cr)_3S_4 and (Cr,Ti)_3S_4. ZnS and ZnSe are proposed to be vapor deposited onto the surface of the specimen to get good colour contrast and good light-dark contrast. The refractive index and absorption coefficient of all these phases have been detemined.
基金supported by the National Research Council of Science & Technology (NST) grant by the Korean government (MSIP) (No. CRC-14-02-ETRI)
文摘To provide a safe transportation system in an extremely cold region,evaluation needs to be conducted of the thickness and the volumetric water content of the active layer,as they significantly affect frost heave.The objective of this study was to evaluate the dielectric constant(κ)of the active layer using ground-penetrating radar(GPR)and a dynamic cone penetrometer(DCP);this evaluation was then used to estimate the thickness and the volumetric water content of the active layer.A field located in midwest Alaska was selected as the study site.A GPR survey and two DCP tests were conducted on the surface of the ground,and the ground temperature was measured.From the GPR survey,travel times of the electromagnetic wave in the active layer were obtained.In addition,the thickness of the active layer was determined by using the dynamic cone penetration index(DCPI)and ground temperature.By using the travel time and travel distance of the electromagnetic wave in the active layer,dielectric constants were calculated as 26.3 and 26.4 for two DCP points.From the mean dielectric constant,the volumetric water content was estimated to be 40%~43%,and the thickness of the active layer was evaluated along the GPR survey line.The spatial-scaled GPR image showed that the thickness of the active layer varied from 520 mm to 700 mm due to the presence of a puddle,which accelerated the heat exchange.The results show that evaluation of the dielectric constant using the GPR survey and the DCP test can be effectively used to estimate the thickness and the volumetric water content of the active layer.
基金Project supported supported by the National Natural Science Foundation of China(Grant Nos.61376099 and 61434007)
文摘H_2O-based and O_3-based La_xAl_yO nanolaminate films were deposited on Si substrates by atomic layer deposition(ALD). Structures and performances of the films were changed by different barrier layers. The effects of different structures on the electrical characteristics and physical properties of the La_xAl_yO films were studied. Chemical bonds in the La_xAl_yO films grown with different structures and different oxidants were also investigated with x-ray photoelectron spectroscopy(XPS). The preliminary testing results indicate that the La_xAl_yO films with different structures and different oxidants show different characteristics, including dielectric constant, equivalent oxide thickness(EOT), electrical properties, and stability.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174182 and 61306113)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20110131110005)
文摘In this study, we investigate the effects of Ga N cap layer thickness on the two-dimensional electron gas(2DEG)electron density and 2DEG electron mobility of Al N/Ga N heterostructures by using the temperature-dependent Hall measurement and theoretical fitting method. The results of our analysis clearly indicate that the Ga N cap layer thickness of an Al N/Ga N heterostructure has influences on the 2DEG electron density and the electron mobility. For the Al N/Ga N heterostructures with a 3-nm Al N barrier layer, the optimized thickness of the Ga N cap layer is around 4 nm and the strained a-axis lattice constant of the Al N barrier layer is less than that of Ga N.
文摘This paper focuses on the design of the cross layer between the video application layer and the MIMO physical layer. MIMO physical layer research has promised an enormous increase in the capacity of wireless communication systems. Also MIMO wireless systems operate under fading conditions where the channel faces arbitrary fluctuations. Since the wireless channel changes over each coherence period, the capacity of the wireless channel, given the power constraints, changes. Hence to make efficient use of the available capacity one needs to adapt the video bit rate. However it is impossible to adapt at the application layer as changing the parameters of the video takes more time than the coherence period of the channel. In this paper we address this problem through a novel solution and also investigate its performance through a simulation study.
文摘A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography plates as a spray reagent. This new reagent enabled to produce various distinguishable colors with amino acids with different RF values. The detection limits and the binding ability of PDBIQ with amino acids have been calculated. PDBIQ is also able to detect aminoacids from hydrolised seed protein. The title compound also exhibited profound inhibitory action against some gm (+ve) and gm (-ve) bacterial organisms. This paper deals with synthesis, spectroscopic application and biological evaluation of the organic moity.