The photoabsorption spectra,of nanoycrystalline silicon(nc-Si:H)films were measured by means of constant photoconductivity method.We investigated the changes of absorption spectra,with the increasing of crystallinity ...The photoabsorption spectra,of nanoycrystalline silicon(nc-Si:H)films were measured by means of constant photoconductivity method.We investigated the changes of absorption spectra,with the increasing of crystallinity as the deposited films are amorphous,micro crystallin e and nan o-crystallin e.We found that in nc-Si:H the transition processes in the interfacial region between the grains predominate the whole range of the absorption spectra.We related the phenomenon to the structural changes in the material.展开更多
The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. A...The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. Among all, the control of ground deformations and variations in sea level has considerable importance. Time series of ground deformation and tidal data in this area have been analysed to highlight these important geophysical features and these results are compared with those obtained from similar data in other time periods. With regard to first mentioned, tiltmetric data have been analysed. These ones come from the tiltmeter network sited in Pozzuoli. Instead, the tidal data come from the tide gauge in Pozzuoli. Data have been analysed by means of a wavelet approach, using a Continuos Wavelet Transform and using, as so-called ＂Wavelet Mother＂, a Gabor-Morlet wavelet. For each time series, the principal harmonic constituents result： lunar semidiurnal （M2）, solar semidiumal （S2） and lunar diurnal （K1）. Other harmonic constituents, having frequencies higher than 1/hour, are present.These last ones could be interpreted as seiches and they could be linked up with generation of discrete plumes of rising magma. Frequencies at which there is the occurrence of these seiches are in agreement with previous studies.展开更多
In this view point paper,we briefly summarize some of the clinical,biochemical and biophysical results obtained in our research on Relaxation Response.We also qualitatively describe the theoretical biophysical model t...In this view point paper,we briefly summarize some of the clinical,biochemical and biophysical results obtained in our research on Relaxation Response.We also qualitatively describe the theoretical biophysical model that could link them.Our work points to a unified view of the human biological system activity,joining the dynamics ruling the interactions and correlations of the microscopic components to the knowledge of their specific individual properties in the effort of going beyond a purely atomistic approach.展开更多
Seismic attributes supported by composite logs are the best way that can enable the interpreter to understand seismic data very well and generate a new view of the output results.Detection of the reservoir zone can be...Seismic attributes supported by composite logs are the best way that can enable the interpreter to understand seismic data very well and generate a new view of the output results.Detection of the reservoir zone can be enhanced by analyzing wells log data based on Gamma-ray,Resistivity,and Vp sonic logs respectively.Composite logs of Scarab-1,Scarab-De,Scarab-Da,Scarab-Dd,and Scarab-2 wells indicate the lateral and vertical variation of the gas reservoir in ElWastani Formation.However,there are several seismic attributes that can be used to support reservoirs identification.For enhancement the detection of the hydrocarbon reservoirs,it is important to carefully analyze the 2D seismic data,which in this study will be primarily prepared to enhance seismic attributes results for the identification of gas chimneys,gas zones as channels,enhance stratigraphic and structural interpretations.In this article,we have performed data conditioning,quality control and seismic well ties including the preliminary wavelet extractions to get accurate output.Then,we have extracted of several classes of physical,geometrical and complex attributes as a direct hydrocarbon indicator to identify the gas zones,channels and chimneys and to identify the faults and discontinuities.The main contribution of this work is to provide a more detailed seismic reflection image supported by several seismic attributes classes and well logs to show a visual and quantitative evidence to identify the gas channels and gas chimneys with improving the detection of the faults and discontinuities.展开更多
The offshore part of the Nile Delta is considered one of the most prolific provinces for gas production andfor future petroleum exploration. Amplitude Variation with Offset (AVO) analysis supported by composite logs c...The offshore part of the Nile Delta is considered one of the most prolific provinces for gas production andfor future petroleum exploration. Amplitude Variation with Offset (AVO) analysis supported by composite logs considered as one of the best-advanced techniques enables the interpreter to understand theseismic data. It is used to generate a new view of the output results, especially for the identification of gaszones as gas channels by using pre-stack AVO attributes that based on the intercept product gradient(A*B) and the Scaled Poisson’s Ratio Change. Free gas, regardless of the percentage show obvious AVOanomaly. Well log data, including gamma-ray, resistivity, and Vp sonic logs are used in the seismic data towell tie and in the generation of the synthetic seismogram. Seismic data conditioning processes withcheck-shot correction is performed to improve the resolution of the reflection events and signal to noiseratio. AVO attributes technique, as a direct hydrocarbon indicator, including AVO gradient analysis andAVO crossplot separate the gas levels in the sand-shale sequences. The identified gas-bearing zonesconsistent with well log data responses. As the main conclusion, we show the visual evidence for the gasbearing zones by interpreting different AVO responses due to the changes in fluid and rock types.展开更多
Ga-doped ZnO nanowires have been synthesized by a pulsed laser chemical vapor deposition method. The crystal structure and photoluminescence spectra indicate that the dopant atoms are well integrated into the ZnO wurt...Ga-doped ZnO nanowires have been synthesized by a pulsed laser chemical vapor deposition method. The crystal structure and photoluminescence spectra indicate that the dopant atoms are well integrated into the ZnO wurtzite lattice. The photocurrent properties at different temperatures have been systematically investigated for nanowires configured as a three-terminal device. Among the experimental highlights, a pronounced semiconductor-to-metal transition occurs upon UV band-to-band excitation. This is a consequence of the reduction in electron mobility arising from the drastically enhanced Coulomb interactions and surface scattering. Another feature is the reproducible presence of two resistance valleys at 220 and 320 K upon light irradiation. This phenomenon originates from the trapping and detrapping processes in the impurity band arising from the native defects as well as the extrinsic Ga dopants. This work demonstrates that due to the dimensional confinement in quasi-one-dimensional structures, enhanced Coulomb interaction, surface scattering, and impurity states can significantly influence charge transport.展开更多
We investigate the tunnel coupling between the outer p-type GaAsSb shell and the n-type InAs core in catalyst-free InAs/lnP/GaAsSb core-dualshell nanowires.We present a device fabrication protocol based on wet-etching...We investigate the tunnel coupling between the outer p-type GaAsSb shell and the n-type InAs core in catalyst-free InAs/lnP/GaAsSb core-dualshell nanowires.We present a device fabrication protocol based on wet-etching processes on selected areas of the nanostructures that enables multiple configurations of measurements in the same nanowire-based device(i.e.shell-shell,core-core and core-shell).Low-temperature(4.2 K)transport in the shell-shell configuration in nanowires with 5 nm-thick InP barrier reveals a weak negative differential resistance.Differently,when the InP barrier thickness is increased to 10 nm,this negative differential resistance is fully quenched.The electrical resistance between the InAs core and the GaAsSb shell,measured in core-shell configuration,is significantly higher with respect to the resistance of the InAs core and of the GaAsSb shell.The field effect,applied via a back-gate,has an opposite impact on the electrical transport in the core and in the shell portions.Our results show that electron and hole free carriers populate the InAs and GaAsSb regions respectively and indicate InAs/InP/GaAsSb core-dualshell nanowires as an ideal system for the investigation of the physics of interacting electrons and holes at the nanoscale.展开更多
In this work,we present a novel biochemical sensing approach based on a plasmonic sensor chip,combined with a specific receptor,excited and interrogated via a custom 3D-printed holder through a transmission-based expe...In this work,we present a novel biochemical sensing approach based on a plasmonic sensor chip,combined with a specific receptor,excited and interrogated via a custom 3D-printed holder through a transmission-based experimental setup,exploiting polymer optical fibers. The setup is designed to measure a disposable plasmonic chip based on a gold nanograting fabricated on a polymethylmethacrylate substrate. The examined sensor configurations here presented are simulated,realized,and experimentally tested. More specifically,first,a numerical analysis is carried out by changing several sensor parameters,then an experimental optical characterization of different sensor configurations is reported. Finally,to test the biosensing capabilities of the proposed method,as a proof of concept,we deposit on the best sensor configuration a biomimetic receptor specific for bovine serum albumin detection. The experimental results demonstrate that the proposed sensor shows an ultra-low limit of detection,equal to about 37 pmol/L.展开更多
Durable dropwise condensation of saturated vapor is of significance for heat transfer and energy saving in extensive industrial applications.While numerous superhydrophobic surfaces can promote steam condensation,main...Durable dropwise condensation of saturated vapor is of significance for heat transfer and energy saving in extensive industrial applications.While numerous superhydrophobic surfaces can promote steam condensation,maintaining discrete microdroplets on surfaces without the formation of a flooded filmwise condensation at high subcooling remains challenging.Here,we report the development of carbon nanotube array-embedded hierarchical composite surfaces that enable ultra-durable dropwise condensation under a wide range of subcooling(ΔT_(sub)=8 K–38 K),which outperforms existing nanowire surfaces.This performance stems from the combined strategies of the hydrophobic nanostructures that allow efficient surface renewal and the patterned hydrophilic micro frames that protect the nanostructures and also accelerate droplet nucleation.The synergistic effects of the composite design ensure sustained Cassie wetting mode and capillarity-governed droplet mobility(Bond number<0.055)as well as the large specific volume of condensed droplets,which contributes to the enhanced condensation heat transfer.Our design provides a feasible alternative for efficiently transferring heat in a vapor environment with relatively high temperatures through the tunable multiscale morphology.展开更多
基金Supported in part by the National Natural Science Foundation of China.
文摘The photoabsorption spectra,of nanoycrystalline silicon(nc-Si:H)films were measured by means of constant photoconductivity method.We investigated the changes of absorption spectra,with the increasing of crystallinity as the deposited films are amorphous,micro crystallin e and nan o-crystallin e.We found that in nc-Si:H the transition processes in the interfacial region between the grains predominate the whole range of the absorption spectra.We related the phenomenon to the structural changes in the material.
文摘The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. Among all, the control of ground deformations and variations in sea level has considerable importance. Time series of ground deformation and tidal data in this area have been analysed to highlight these important geophysical features and these results are compared with those obtained from similar data in other time periods. With regard to first mentioned, tiltmetric data have been analysed. These ones come from the tiltmeter network sited in Pozzuoli. Instead, the tidal data come from the tide gauge in Pozzuoli. Data have been analysed by means of a wavelet approach, using a Continuos Wavelet Transform and using, as so-called ＂Wavelet Mother＂, a Gabor-Morlet wavelet. For each time series, the principal harmonic constituents result： lunar semidiurnal （M2）, solar semidiumal （S2） and lunar diurnal （K1）. Other harmonic constituents, having frequencies higher than 1/hour, are present.These last ones could be interpreted as seiches and they could be linked up with generation of discrete plumes of rising magma. Frequencies at which there is the occurrence of these seiches are in agreement with previous studies.
文摘In this view point paper,we briefly summarize some of the clinical,biochemical and biophysical results obtained in our research on Relaxation Response.We also qualitatively describe the theoretical biophysical model that could link them.Our work points to a unified view of the human biological system activity,joining the dynamics ruling the interactions and correlations of the microscopic components to the knowledge of their specific individual properties in the effort of going beyond a purely atomistic approach.
基金supported by a part of the Egyptian General Petroleum Corporation(EGPC)project in west offshore Nile Delta,Egypt.
文摘Seismic attributes supported by composite logs are the best way that can enable the interpreter to understand seismic data very well and generate a new view of the output results.Detection of the reservoir zone can be enhanced by analyzing wells log data based on Gamma-ray,Resistivity,and Vp sonic logs respectively.Composite logs of Scarab-1,Scarab-De,Scarab-Da,Scarab-Dd,and Scarab-2 wells indicate the lateral and vertical variation of the gas reservoir in ElWastani Formation.However,there are several seismic attributes that can be used to support reservoirs identification.For enhancement the detection of the hydrocarbon reservoirs,it is important to carefully analyze the 2D seismic data,which in this study will be primarily prepared to enhance seismic attributes results for the identification of gas chimneys,gas zones as channels,enhance stratigraphic and structural interpretations.In this article,we have performed data conditioning,quality control and seismic well ties including the preliminary wavelet extractions to get accurate output.Then,we have extracted of several classes of physical,geometrical and complex attributes as a direct hydrocarbon indicator to identify the gas zones,channels and chimneys and to identify the faults and discontinuities.The main contribution of this work is to provide a more detailed seismic reflection image supported by several seismic attributes classes and well logs to show a visual and quantitative evidence to identify the gas channels and gas chimneys with improving the detection of the faults and discontinuities.
文摘The offshore part of the Nile Delta is considered one of the most prolific provinces for gas production andfor future petroleum exploration. Amplitude Variation with Offset (AVO) analysis supported by composite logs considered as one of the best-advanced techniques enables the interpreter to understand theseismic data. It is used to generate a new view of the output results, especially for the identification of gaszones as gas channels by using pre-stack AVO attributes that based on the intercept product gradient(A*B) and the Scaled Poisson’s Ratio Change. Free gas, regardless of the percentage show obvious AVOanomaly. Well log data, including gamma-ray, resistivity, and Vp sonic logs are used in the seismic data towell tie and in the generation of the synthetic seismogram. Seismic data conditioning processes withcheck-shot correction is performed to improve the resolution of the reflection events and signal to noiseratio. AVO attributes technique, as a direct hydrocarbon indicator, including AVO gradient analysis andAVO crossplot separate the gas levels in the sand-shale sequences. The identified gas-bearing zonesconsistent with well log data responses. As the main conclusion, we show the visual evidence for the gasbearing zones by interpreting different AVO responses due to the changes in fluid and rock types.
文摘Ga-doped ZnO nanowires have been synthesized by a pulsed laser chemical vapor deposition method. The crystal structure and photoluminescence spectra indicate that the dopant atoms are well integrated into the ZnO wurtzite lattice. The photocurrent properties at different temperatures have been systematically investigated for nanowires configured as a three-terminal device. Among the experimental highlights, a pronounced semiconductor-to-metal transition occurs upon UV band-to-band excitation. This is a consequence of the reduction in electron mobility arising from the drastically enhanced Coulomb interactions and surface scattering. Another feature is the reproducible presence of two resistance valleys at 220 and 320 K upon light irradiation. This phenomenon originates from the trapping and detrapping processes in the impurity band arising from the native defects as well as the extrinsic Ga dopants. This work demonstrates that due to the dimensional confinement in quasi-one-dimensional structures, enhanced Coulomb interaction, surface scattering, and impurity states can significantly influence charge transport.
基金This research activity was partially supported by the SUPERTOP project,QUANTERA ERA-NET Cofound in Quantum Technologies,and by the FET-OPEN project AndQC.
文摘We investigate the tunnel coupling between the outer p-type GaAsSb shell and the n-type InAs core in catalyst-free InAs/lnP/GaAsSb core-dualshell nanowires.We present a device fabrication protocol based on wet-etching processes on selected areas of the nanostructures that enables multiple configurations of measurements in the same nanowire-based device(i.e.shell-shell,core-core and core-shell).Low-temperature(4.2 K)transport in the shell-shell configuration in nanowires with 5 nm-thick InP barrier reveals a weak negative differential resistance.Differently,when the InP barrier thickness is increased to 10 nm,this negative differential resistance is fully quenched.The electrical resistance between the InAs core and the GaAsSb shell,measured in core-shell configuration,is significantly higher with respect to the resistance of the InAs core and of the GaAsSb shell.The field effect,applied via a back-gate,has an opposite impact on the electrical transport in the core and in the shell portions.Our results show that electron and hole free carriers populate the InAs and GaAsSb regions respectively and indicate InAs/InP/GaAsSb core-dualshell nanowires as an ideal system for the investigation of the physics of interacting electrons and holes at the nanoscale.
文摘In this work,we present a novel biochemical sensing approach based on a plasmonic sensor chip,combined with a specific receptor,excited and interrogated via a custom 3D-printed holder through a transmission-based experimental setup,exploiting polymer optical fibers. The setup is designed to measure a disposable plasmonic chip based on a gold nanograting fabricated on a polymethylmethacrylate substrate. The examined sensor configurations here presented are simulated,realized,and experimentally tested. More specifically,first,a numerical analysis is carried out by changing several sensor parameters,then an experimental optical characterization of different sensor configurations is reported. Finally,to test the biosensing capabilities of the proposed method,as a proof of concept,we deposit on the best sensor configuration a biomimetic receptor specific for bovine serum albumin detection. The experimental results demonstrate that the proposed sensor shows an ultra-low limit of detection,equal to about 37 pmol/L.
基金L.-W.Zhang acknowledges the support from the Marine Equipment Foresight Innovation Union Project(A-03).
文摘Durable dropwise condensation of saturated vapor is of significance for heat transfer and energy saving in extensive industrial applications.While numerous superhydrophobic surfaces can promote steam condensation,maintaining discrete microdroplets on surfaces without the formation of a flooded filmwise condensation at high subcooling remains challenging.Here,we report the development of carbon nanotube array-embedded hierarchical composite surfaces that enable ultra-durable dropwise condensation under a wide range of subcooling(ΔT_(sub)=8 K–38 K),which outperforms existing nanowire surfaces.This performance stems from the combined strategies of the hydrophobic nanostructures that allow efficient surface renewal and the patterned hydrophilic micro frames that protect the nanostructures and also accelerate droplet nucleation.The synergistic effects of the composite design ensure sustained Cassie wetting mode and capillarity-governed droplet mobility(Bond number<0.055)as well as the large specific volume of condensed droplets,which contributes to the enhanced condensation heat transfer.Our design provides a feasible alternative for efficiently transferring heat in a vapor environment with relatively high temperatures through the tunable multiscale morphology.
