Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The s...Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The sensor consists of a 1μm thick silicon nitride (SiN_y) intermediate layer deposited by electron beam evaporation on a 36°Y-cut X-propagating piezoelectric lithium tantalate (LiTaO_3) substrate and a 100 nm thin indium oxide (InO_x) sensing layer deposited by R.F.magnetron sputtering.The device fabrication is described and the performance of the sensor is analyzed in terms of response magnitude as a function of operating temperature.Large frequency shifts of 360 kHz for 600μg/g of H_2 and 92 kHz for 40 ng/g O_3 were recorded.In addition,the surface morphology of the deposited films were investigated by Atomic Force Microscopy (AFM) and the chemical composition by X-Ray Photoelectron Spectroscopy (XPS) to correlate gas-sensing behavior to structural characteristics of the thin film.展开更多
In order to suppress the influence of temperature changes on the performance of accelerometers,a digital quartz resonant accelerometer with low temperature drift is developed using a quartz resonator cluster as a tran...In order to suppress the influence of temperature changes on the performance of accelerometers,a digital quartz resonant accelerometer with low temperature drift is developed using a quartz resonator cluster as a transducer element.In addition,a digital intellectual property(IP) is designed in FPGA to achieve signal processing and fusion of integrated resonators.A testing system for digital quartz resonant accelerometers is established to characterize the performance under different conditions.The scale factor of the accelerometer prototype reaches 3561.63 Hz/g in the range of -1 g to +1 g,and 3542.5 Hz/g in the range of-10 g to+10 g.In different measurement ranges,the linear correlation coefficient R~2 of the accelerometer achieves greater than 0.998.The temperature drift of the accelerometer prototype is tested using a constant temperature test chamber,with a temperature change from -20℃ to 80℃.After temperature-drift compensation,the zero bias temperature coefficient falls to 0.08 mg/℃,and the scale factor temperature coefficient is 65.43 ppm/℃.The experimental results show that the digital quartz resonant accelerometer exhibits excellent sensitivity and low temperature drift.展开更多
Pesticides have the potential to leave harmful effects on humans, animals, other living organisms, and the environment. Several human metabolic proteins inhibited after exposure to organophosphorus pesticides absorbed...Pesticides have the potential to leave harmful effects on humans, animals, other living organisms, and the environment. Several human metabolic proteins inhibited after exposure to organophosphorus pesticides absorbed through the skin, inhalation, eyes and oral mucosa, are most important targets for this interaction study. The crystal structure of five different proteins, PDBIDs： 3LII, 3NXU, 4GTU, 2XJ1 and 1YXA in Homo sapiens （H. sapiens）, interact with organophosphorus pesticides at the molecular level. The 3-D structures were found to be of good quality and validated through PROCHECK, ERRAT and ProSA servers. The results show that the binding energy is maximum -45.21 relative units of cytochrome P450 protein with phosmet pesticide. In terms of H-bonding, methyl parathion and parathion with acetylcholinesterase protein, parathion, methylparathion and phosmet with protein kinase C show the highest interaction. We conclude that these organophosphorus pesticides are more toxic and inhibit enzymatic activity by interrupting the metabolic pathways in H. sapiens.展开更多
The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural pr...The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural prop- erties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using ~H-NMR. The ~H- NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm （8） with the coupling constants of 11-16 Hz （Je-cns）. In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm （8） with the coupling constant of 10 Hz （Je-cH2） and the methylene resonances was 4.2-4.4 ppm （8） with the coupling constant of 0.8 Hz （Jp-cH3）, respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.展开更多
In the present endeavour, SnO2 nanoparticles (NPs) were synthesized using microwave method. Synthesized SnO2 NPs were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersi...In the present endeavour, SnO2 nanoparticles (NPs) were synthesized using microwave method. Synthesized SnO2 NPs were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrscopy (EDS) to find their structure, morphology and elemental composition. SnO2 NPs were of spherical morphology having crystallite size of 35.42 nm as obtained from Scherrer’s formula using most intense peak of XRD. Synthesized NPs were used for photodegradation of melthylene blue (MB) dye under UV light. The SnO2 NPs ware found to have photodegradation efficiency and apparent rate constant of 55.97% and 2.149 × 10_2 respectively.展开更多
We have comparatively studied the addition of Cr and V in titania.Cr and V content were changed by means of insets placed in the Ti target.Structural,compositional and electrical analyses of different series of thin f...We have comparatively studied the addition of Cr and V in titania.Cr and V content were changed by means of insets placed in the Ti target.Structural,compositional and electrical analyses of different series of thin films,made by XRF, XRD,are presented.Electrical characterization not only showed that Cr doped layers were very sensitive to ethanol within a useful range for applications,but also allowed to verify that the electrical behaviour is dependent on the structure of film. Finally,the Cr and V concentrations that gives the best results in terms of sensing performances has been determined and a correlation between structural and electrical measurement has been evidenced.展开更多
In the present work,zinc oxide(ZnO)and silver(Ag)doped ZnO nanostructures are synthesized using a hydrothermal method.Structural quality of the products is attested using X-ray diffraction,which confirms the hexagonal...In the present work,zinc oxide(ZnO)and silver(Ag)doped ZnO nanostructures are synthesized using a hydrothermal method.Structural quality of the products is attested using X-ray diffraction,which confirms the hexagonal wurtzite struc-ture of pure ZnO and Ag-doped ZnO nanostructures.XRD further confirms the crystallite orientation along the c-axis,(101)plane.The field emission scanning electron microscope study reveals the change in shape of the synthesized ZnO particles from hexagonal nanoparticles to needle-shaped nanostructures for 3 wt%Ag-doped ZnO.The optical band gaps and lattice strain of nanostructures is increased significantly with the increase of doping concentration of Ag in ZnO nanostructure.The anti-microbial activity of synthesized nanostructures has been evaluated against the gram-positive human pathogenic bacteria,Staphylococcus aureus via an agarose gel diffusion test.The maximum value of zone of inhibition(22 mm)is achieved for 3 wt%Ag-doped ZnO nanostructure and it clearly demonstrates the remarkable antibacterial activity.展开更多
A detailed study is reported of the synthesis and characterization of n- type ZnO nanomaterial and its application as temperature sensor. The ZnO nanomaterial has been synthesized through pyrolysis of the oxalate prod...A detailed study is reported of the synthesis and characterization of n- type ZnO nanomaterial and its application as temperature sensor. The ZnO nanomaterial has been synthesized through pyrolysis of the oxalate produced by a conventional precipitation method. It is synthesized by flash heating the oxalate at 450°C for 15 min. Pellet of this material was prepared and used as a sensing element. The variations in resistance of sensing pellet at different temperatures were recorded. The relative resistance was decreased linearly with increasing temperatures over the range, 120°C - 260°C. The activation energy of ZnO calculated from Arrhenius plot was found 1.12 eV. Temperature response in terms of the relative variation, ΔR, of sensor resistance to a given temperature was measured. Scanning electron micrograph of the sensing element has been studied. Pellet of the ZnO is comprised of nanorods of varying diameters and different lengths. Diameter of ZnO nanorods varies from 75 to 300 nm. X-ray diffraction pattern of the sensing element reveal their nano-crystalline nature. Optical characterization of the sensing material was carried out by UV-visible spectrophotometer. By UV-Vis spectra, the estimated value of band gap of ZnO was found 4.7 eV.展开更多
Aging degradation and seismic damage of civil infrastructures have become a serious issue for society,and one promising technology for monitoring their conditions is optical fiber sensing.Glass optical fibers have bee...Aging degradation and seismic damage of civil infrastructures have become a serious issue for society,and one promising technology for monitoring their conditions is optical fiber sensing.Glass optical fibers have been predominantly used for the past several decades to develop fiber sensors,but currently polymer or plastic optical fibers(POFs)have also been used extensively to develop advanced fiber sensors because of their unique features,such as high flexibility,large breakage strain,and impact resistance.This review focuses on recently developed distributed and quasi-distributed POF-based sensing techniques based on Rayleigh scattering,Brillouin scattering,and fiber Bragg gratings.展开更多
The objective of this work is to prepare the Pd-decorated WS^(2)nanostructures using a hydrothermal technique,which is subsequently utilized in designing a photodetector device for detecting different wavelengths of t...The objective of this work is to prepare the Pd-decorated WS^(2)nanostructures using a hydrothermal technique,which is subsequently utilized in designing a photodetector device for detecting different wavelengths of the solar spectrum.Broadband photodetection can be significantly enhanced by developing transition metal dichalcogenides with tunable band gaps and unique electrical and optical properties.The X-ray photoelectron spectroscopy analysis has confirmed the presence of W 4+oxidation states,as evidenced by the observation of peaks corresponding to W5p_(3/2),W4f_(3/2),and W4f_(7/2)with binding energies of 37.83,34.36,and 32.29 eV respectively.Plasmonic photodetector offers advantageous characteristics such as the ability to provide photodetection of different wavelengths by a single photodetector device.WS2exhibits a notable responsivity of 125 mA·W^(-1)and a detectivity of 8.40×1010cm·Hz^(1/2)·W^(-1).On decorating with Pd,the responsivity and detectivity of the device increase up to 4.25 A·W-1and 1.16×10^(14)cm·Hz^(1/2)·W^(-1),respectively.By utilizing the plasmons at the semiconductor surface,a surface plasmon effect has been produced,thereby increasing the photocurrent value and offering numerous advantageous features.展开更多
Artificial intelligence(AI)advancements are driving the need for highly paral-lel and energy-efficient computing analogous to the human brain and visualsystem.Inspired by the human brain,resistive random-access memori...Artificial intelligence(AI)advancements are driving the need for highly paral-lel and energy-efficient computing analogous to the human brain and visualsystem.Inspired by the human brain,resistive random-access memories(ReRAMs)have recently emerged as an essential component of the intelligentcircuitry architecture for developing high-performance neuromorphic comput-ing systems.This occurs due to their fast switching with ultralow power con-sumption,high ON/OFF ratio,excellent data retention,good endurance,andeven great possibilities for altering resistance analogous to their biologicalcounterparts for neuromorphic computing applications.Additionally,with theadvantages of photoelectric dual modulation of resistive switching,ReRAMsallow optically inspired artificial neural networks and reconfigurable logicoperations,promoting innovative in-memory computing technology forneuromorphic computing and image recognition tasks.Optoelectronicneuromorphic computing architectured ReRAMs can simulate neural func-tionalities,such as light-triggered long-term/short-term plasticity.They can beused in intelligent robotics and bionic neurological optoelectronic systems.Metal oxide(MOx)–polymer hybrid nanocomposites can be beneficial as anactive layer of the bistable metal–insulator–metal ReRAM devices,which holdpromise for developing high-performance memory technology.This reviewexplores the state of the art for developing memory storage,advancement inmaterials,and switching mechanisms for selecting the appropriate materials asactive layers of ReRAMs to boost the ON/OFF ratio,flexibility,and memorydensity while lowering programming voltage.Furthermore,material designcum-synthesis strategies that greatly influence the overall performance of MOx–polymer hybrid nanocomposite ReRAMs and their performances arehighlighted.Additionally,the recent progress of multifunctional optoelectronicMOx–polymer hybrid composites-based ReRAMs are explored as artificial syn-apses for neural networks to emulate neuromorphic visualization and memo-rize information.Finally,the challenges,limitations,and future outlooks ofthe fabrication of MOx–polymer hybrid composite ReRAMs over the conven-tional von Neumann computing systems are discussed.展开更多
The controllability of persistent photoconductance （PPC） and charge/energy storage of ZnO nanorod arrays （NRAs） were demonstrated experimentally by tuning the nanorod diameter. The dependency of the ZnO NRAs＇ pho...The controllability of persistent photoconductance （PPC） and charge/energy storage of ZnO nanorod arrays （NRAs） were demonstrated experimentally by tuning the nanorod diameter. The dependency of the ZnO NRAs＇ photoelectric characteristics on the nanorod diameter suggests that the Debye length and photon penetration depth in ZnO could spatially partition a standalone nanorod into three different photoelectric functional regions （PFRs）. Theoretically, a series of rate functions was employed to describe the different extrinsic/intrinsic carrier photogeneration/recombination dynamic sub-processes occurring in the different PFRs, associated with oxygen chemisorption/photodesorption, oxygen vacancy photoionization, and electron trapping by photoionized oxygen vacancies. On the basis of the coupled contributions of these different dynamic sub-processes in the photoelectric properties of the ZnO NRAs, a thorough-process photoelectric dynamic model （TPDM） was proposed using the simultaneous rate functions. Through solving the rate functions, the corresponding analytical equations could be employed to simulate the time-resolved PPC spectra of the ZnO NRAs, and then the quantitative parameters extracted to decipher the PPC and charge/energy storage mechanisms in the ZnO NRAs. In this way, the TPDM model provided a numerical-analytical method to quantitatively evaluate the photoelectric properties of ZnO NRA-based devices. Additionally, the TPDM model revealed how the different photoinduced carrier dynamics in the different PFRs could play functional roles in different optoelectronic applications, e.g., photodetectors, photocatalysts, solar cells and optical nonvolatile memories, and thus it illuminated a practical approach for the design of ZnO NRA-based devices via optimization of the modularized spatial configuration of the PFRs.展开更多
Collective oscillations of massless particles in two-dimensional(2D)Dirac materials offer an innovative route toward implementing atomically thin devices based on low-energy quasiparticle interactions.Strong confineme...Collective oscillations of massless particles in two-dimensional(2D)Dirac materials offer an innovative route toward implementing atomically thin devices based on low-energy quasiparticle interactions.Strong confinement of nearfield distribution on the 2D surface is essential to demonstrate extraordinary optoelectronic functions,providing means to shape the spectral response at the mid-infrared(IR)wavelength.Although the dynamic polarization from the linear response theory has successfully accounted for a range of experimental observations,a unified perspective was stll elusive,connecting the state-of-the-art developments based on the 2D Dirac plasmon-polaritons.Here,we review recent works on graphene and three-dimensional(3D)topological insulator(TI)plasmon-polariton,where the mid-IR and terahertz(THz)radiation experiences prominent confinement into a deep-subwavelength scale in a novel optoelectronic structure.After presenting general light-matter interactions between 2D Dirac plasmon and subwavelength quasiparticle excitations,we introduce various experimental techniques to couple the plasmonpolaritons with electromagnetic radiations.Electrical and optical controls over the plasmonic excitations reveal the hybridized plasmon modes in graphene and 3D Tl,demonstrating an intense near-field interaction of 2D Dirac plasmon within the highly-compressed volume.These findings can further be applied to invent optoelectronic biomolecular sensors,atomically thin photodetectors,and laser-driven light sources.展开更多
A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an...A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.展开更多
An experimental platform was developed to investigate the effects of audible sound(20 Hz to 20 MHz)on plant growth promotion,which included a microcontroller-based embedded system for audible sound adjustment and anal...An experimental platform was developed to investigate the effects of audible sound(20 Hz to 20 MHz)on plant growth promotion,which included a microcontroller-based embedded system for audible sound adjustment and analysis.The direct digital frequency synthesis(DDFS)method was used to generate various waveforms of sound in the platform.Soundproof glass and mufflers were used to reduce background noise.The developed system was tested on various plants,including hydroponic tomatoes,celery and mung bean.The testing results showed that the developed platform could produce pure tone and mixing audible sound with high stability and accuracy,make octave analysis of the sound under experimental environments,and the background noise in the testing chamber of the platform was lower than 55 dB(A)when the compression engine was working.The developed experimental platform has a great potential on facilitating scientific research on acoustic biology effects on plants and collecting real-time experimental data.展开更多
文摘Layered Surface Acoustic Wave (SAW) devices with an InO_x/SiN_u/36°YX LiTaO_3 structure were investigated for sensing low concentrations of hydrogen (H_2) and ozone (O_3) at different operating temperatures.The sensor consists of a 1μm thick silicon nitride (SiN_y) intermediate layer deposited by electron beam evaporation on a 36°Y-cut X-propagating piezoelectric lithium tantalate (LiTaO_3) substrate and a 100 nm thin indium oxide (InO_x) sensing layer deposited by R.F.magnetron sputtering.The device fabrication is described and the performance of the sensor is analyzed in terms of response magnitude as a function of operating temperature.Large frequency shifts of 360 kHz for 600μg/g of H_2 and 92 kHz for 40 ng/g O_3 were recorded.In addition,the surface morphology of the deposited films were investigated by Atomic Force Microscopy (AFM) and the chemical composition by X-Ray Photoelectron Spectroscopy (XPS) to correlate gas-sensing behavior to structural characteristics of the thin film.
文摘In order to suppress the influence of temperature changes on the performance of accelerometers,a digital quartz resonant accelerometer with low temperature drift is developed using a quartz resonator cluster as a transducer element.In addition,a digital intellectual property(IP) is designed in FPGA to achieve signal processing and fusion of integrated resonators.A testing system for digital quartz resonant accelerometers is established to characterize the performance under different conditions.The scale factor of the accelerometer prototype reaches 3561.63 Hz/g in the range of -1 g to +1 g,and 3542.5 Hz/g in the range of-10 g to+10 g.In different measurement ranges,the linear correlation coefficient R~2 of the accelerometer achieves greater than 0.998.The temperature drift of the accelerometer prototype is tested using a constant temperature test chamber,with a temperature change from -20℃ to 80℃.After temperature-drift compensation,the zero bias temperature coefficient falls to 0.08 mg/℃,and the scale factor temperature coefficient is 65.43 ppm/℃.The experimental results show that the digital quartz resonant accelerometer exhibits excellent sensitivity and low temperature drift.
文摘Pesticides have the potential to leave harmful effects on humans, animals, other living organisms, and the environment. Several human metabolic proteins inhibited after exposure to organophosphorus pesticides absorbed through the skin, inhalation, eyes and oral mucosa, are most important targets for this interaction study. The crystal structure of five different proteins, PDBIDs： 3LII, 3NXU, 4GTU, 2XJ1 and 1YXA in Homo sapiens （H. sapiens）, interact with organophosphorus pesticides at the molecular level. The 3-D structures were found to be of good quality and validated through PROCHECK, ERRAT and ProSA servers. The results show that the binding energy is maximum -45.21 relative units of cytochrome P450 protein with phosmet pesticide. In terms of H-bonding, methyl parathion and parathion with acetylcholinesterase protein, parathion, methylparathion and phosmet with protein kinase C show the highest interaction. We conclude that these organophosphorus pesticides are more toxic and inhibit enzymatic activity by interrupting the metabolic pathways in H. sapiens.
文摘The purpose of this study was to investigate the nuclear magnetic resonance （NMR） assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural prop- erties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using ~H-NMR. The ~H- NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm （8） with the coupling constants of 11-16 Hz （Je-cns）. In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm （8） with the coupling constant of 10 Hz （Je-cH2） and the methylene resonances was 4.2-4.4 ppm （8） with the coupling constant of 0.8 Hz （Jp-cH3）, respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.
文摘In the present endeavour, SnO2 nanoparticles (NPs) were synthesized using microwave method. Synthesized SnO2 NPs were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrscopy (EDS) to find their structure, morphology and elemental composition. SnO2 NPs were of spherical morphology having crystallite size of 35.42 nm as obtained from Scherrer’s formula using most intense peak of XRD. Synthesized NPs were used for photodegradation of melthylene blue (MB) dye under UV light. The SnO2 NPs ware found to have photodegradation efficiency and apparent rate constant of 55.97% and 2.149 × 10_2 respectively.
文摘We have comparatively studied the addition of Cr and V in titania.Cr and V content were changed by means of insets placed in the Ti target.Structural,compositional and electrical analyses of different series of thin films,made by XRF, XRD,are presented.Electrical characterization not only showed that Cr doped layers were very sensitive to ethanol within a useful range for applications,but also allowed to verify that the electrical behaviour is dependent on the structure of film. Finally,the Cr and V concentrations that gives the best results in terms of sensing performances has been determined and a correlation between structural and electrical measurement has been evidenced.
基金the research facilities in the Department of Physics,Ch.Charan Singh University,Meerut,Uttar Pradesh,India.This work was supported by the UGC,Govt.of India[No.F.30-303/2016(BSR),F.D.Dy.No.11299]。
文摘In the present work,zinc oxide(ZnO)and silver(Ag)doped ZnO nanostructures are synthesized using a hydrothermal method.Structural quality of the products is attested using X-ray diffraction,which confirms the hexagonal wurtzite struc-ture of pure ZnO and Ag-doped ZnO nanostructures.XRD further confirms the crystallite orientation along the c-axis,(101)plane.The field emission scanning electron microscope study reveals the change in shape of the synthesized ZnO particles from hexagonal nanoparticles to needle-shaped nanostructures for 3 wt%Ag-doped ZnO.The optical band gaps and lattice strain of nanostructures is increased significantly with the increase of doping concentration of Ag in ZnO nanostructure.The anti-microbial activity of synthesized nanostructures has been evaluated against the gram-positive human pathogenic bacteria,Staphylococcus aureus via an agarose gel diffusion test.The maximum value of zone of inhibition(22 mm)is achieved for 3 wt%Ag-doped ZnO nanostructure and it clearly demonstrates the remarkable antibacterial activity.
文摘A detailed study is reported of the synthesis and characterization of n- type ZnO nanomaterial and its application as temperature sensor. The ZnO nanomaterial has been synthesized through pyrolysis of the oxalate produced by a conventional precipitation method. It is synthesized by flash heating the oxalate at 450°C for 15 min. Pellet of this material was prepared and used as a sensing element. The variations in resistance of sensing pellet at different temperatures were recorded. The relative resistance was decreased linearly with increasing temperatures over the range, 120°C - 260°C. The activation energy of ZnO calculated from Arrhenius plot was found 1.12 eV. Temperature response in terms of the relative variation, ΔR, of sensor resistance to a given temperature was measured. Scanning electron micrograph of the sensing element has been studied. Pellet of the ZnO is comprised of nanorods of varying diameters and different lengths. Diameter of ZnO nanorods varies from 75 to 300 nm. X-ray diffraction pattern of the sensing element reveal their nano-crystalline nature. Optical characterization of the sensing material was carried out by UV-visible spectrophotometer. By UV-Vis spectra, the estimated value of band gap of ZnO was found 4.7 eV.
基金Japan Society for the Promotion of Science(17H04930,20K22417,21H04555)Noguchi Institute+5 种基金Murata Science FoundationTelecommunications Advancement FoundationYazaki Memorial Foundation for Science and TechnologyTakahashi Industrial and Economic Research FoundationEuropean Regional Development Fundthe Republic of Cyprus through the Research and Innovation Foundation(INTEGRATED/0918/0031)。
文摘Aging degradation and seismic damage of civil infrastructures have become a serious issue for society,and one promising technology for monitoring their conditions is optical fiber sensing.Glass optical fibers have been predominantly used for the past several decades to develop fiber sensors,but currently polymer or plastic optical fibers(POFs)have also been used extensively to develop advanced fiber sensors because of their unique features,such as high flexibility,large breakage strain,and impact resistance.This review focuses on recently developed distributed and quasi-distributed POF-based sensing techniques based on Rayleigh scattering,Brillouin scattering,and fiber Bragg gratings.
基金the Council of Scientific&Industrial Research and University Grant Commission(CSIRUGC),the Government of India for financial support in the form of a Junior Research Fellowship(NTA Ref.No.:231610026817)。
文摘The objective of this work is to prepare the Pd-decorated WS^(2)nanostructures using a hydrothermal technique,which is subsequently utilized in designing a photodetector device for detecting different wavelengths of the solar spectrum.Broadband photodetection can be significantly enhanced by developing transition metal dichalcogenides with tunable band gaps and unique electrical and optical properties.The X-ray photoelectron spectroscopy analysis has confirmed the presence of W 4+oxidation states,as evidenced by the observation of peaks corresponding to W5p_(3/2),W4f_(3/2),and W4f_(7/2)with binding energies of 37.83,34.36,and 32.29 eV respectively.Plasmonic photodetector offers advantageous characteristics such as the ability to provide photodetection of different wavelengths by a single photodetector device.WS2exhibits a notable responsivity of 125 mA·W^(-1)and a detectivity of 8.40×1010cm·Hz^(1/2)·W^(-1).On decorating with Pd,the responsivity and detectivity of the device increase up to 4.25 A·W-1and 1.16×10^(14)cm·Hz^(1/2)·W^(-1),respectively.By utilizing the plasmons at the semiconductor surface,a surface plasmon effect has been produced,thereby increasing the photocurrent value and offering numerous advantageous features.
基金Council of Scientific and Industrial Research,India,Grant/Award Number:08/096(0012)/2020-EMR-IGovernment of Uttar Pradesh,India,Grant/Award Numbers:108/2021/2585/Sattar-4-2021-4(28)/2021/20,78/2022/1984/Sattar-4-2022-003-70-4099/7/022/19,CST/D-1524+1 种基金Chaudhary Charan Singh University,India,Grant/Award Number:Dev./1043/29.06.2022National Research Foundation of Korea,Grant/Award Numbers:2019R1A2C1085448,2023R1A2C1005421。
文摘Artificial intelligence(AI)advancements are driving the need for highly paral-lel and energy-efficient computing analogous to the human brain and visualsystem.Inspired by the human brain,resistive random-access memories(ReRAMs)have recently emerged as an essential component of the intelligentcircuitry architecture for developing high-performance neuromorphic comput-ing systems.This occurs due to their fast switching with ultralow power con-sumption,high ON/OFF ratio,excellent data retention,good endurance,andeven great possibilities for altering resistance analogous to their biologicalcounterparts for neuromorphic computing applications.Additionally,with theadvantages of photoelectric dual modulation of resistive switching,ReRAMsallow optically inspired artificial neural networks and reconfigurable logicoperations,promoting innovative in-memory computing technology forneuromorphic computing and image recognition tasks.Optoelectronicneuromorphic computing architectured ReRAMs can simulate neural func-tionalities,such as light-triggered long-term/short-term plasticity.They can beused in intelligent robotics and bionic neurological optoelectronic systems.Metal oxide(MOx)–polymer hybrid nanocomposites can be beneficial as anactive layer of the bistable metal–insulator–metal ReRAM devices,which holdpromise for developing high-performance memory technology.This reviewexplores the state of the art for developing memory storage,advancement inmaterials,and switching mechanisms for selecting the appropriate materials asactive layers of ReRAMs to boost the ON/OFF ratio,flexibility,and memorydensity while lowering programming voltage.Furthermore,material designcum-synthesis strategies that greatly influence the overall performance of MOx–polymer hybrid nanocomposite ReRAMs and their performances arehighlighted.Additionally,the recent progress of multifunctional optoelectronicMOx–polymer hybrid composites-based ReRAMs are explored as artificial syn-apses for neural networks to emulate neuromorphic visualization and memo-rize information.Finally,the challenges,limitations,and future outlooks ofthe fabrication of MOx–polymer hybrid composite ReRAMs over the conven-tional von Neumann computing systems are discussed.
基金This work was supported by National Natural Science Foundation of China （No. 50927201） and the National Basic Research Program of China （Nos. 2009CB939705 and 2009CB939702）. The authors are also grateful to Analytical and Testing Center of Huazhong University of Science and Technology.
文摘The controllability of persistent photoconductance （PPC） and charge/energy storage of ZnO nanorod arrays （NRAs） were demonstrated experimentally by tuning the nanorod diameter. The dependency of the ZnO NRAs＇ photoelectric characteristics on the nanorod diameter suggests that the Debye length and photon penetration depth in ZnO could spatially partition a standalone nanorod into three different photoelectric functional regions （PFRs）. Theoretically, a series of rate functions was employed to describe the different extrinsic/intrinsic carrier photogeneration/recombination dynamic sub-processes occurring in the different PFRs, associated with oxygen chemisorption/photodesorption, oxygen vacancy photoionization, and electron trapping by photoionized oxygen vacancies. On the basis of the coupled contributions of these different dynamic sub-processes in the photoelectric properties of the ZnO NRAs, a thorough-process photoelectric dynamic model （TPDM） was proposed using the simultaneous rate functions. Through solving the rate functions, the corresponding analytical equations could be employed to simulate the time-resolved PPC spectra of the ZnO NRAs, and then the quantitative parameters extracted to decipher the PPC and charge/energy storage mechanisms in the ZnO NRAs. In this way, the TPDM model provided a numerical-analytical method to quantitatively evaluate the photoelectric properties of ZnO NRA-based devices. Additionally, the TPDM model revealed how the different photoinduced carrier dynamics in the different PFRs could play functional roles in different optoelectronic applications, e.g., photodetectors, photocatalysts, solar cells and optical nonvolatile memories, and thus it illuminated a practical approach for the design of ZnO NRA-based devices via optimization of the modularized spatial configuration of the PFRs.
基金C.I.and H.C.were supported by the National Research Foundation of Korea(NRF)through the government of Korea(Grant No.NRF-2021R1A2C3005905,NRF-2020M3F3A2A03082472)Creative materials Discovery program(grant no.2017M3D1A1040834)+4 种基金Scalable Quantum Computer Technology Platform Center(grant no.2019R1A5A1027055)the core center program(2021R1A6C101B418)the Ministry of Education,and the Institute for Basic Science(IBS),Korea,under Project C ode IBS-R014-G1-2018-A1Part of this study(C.I.and H.C.)has been performed using failities at IBS Center for Correlated Electron Systems,Seoul National University.C.I.was supported by NRF through the government of Korea(Grant No.NRF-2021R1A6A3A14044225)This work was supported by Samsung Advanced Institute of technology in 2014-2018.
文摘Collective oscillations of massless particles in two-dimensional(2D)Dirac materials offer an innovative route toward implementing atomically thin devices based on low-energy quasiparticle interactions.Strong confinement of nearfield distribution on the 2D surface is essential to demonstrate extraordinary optoelectronic functions,providing means to shape the spectral response at the mid-infrared(IR)wavelength.Although the dynamic polarization from the linear response theory has successfully accounted for a range of experimental observations,a unified perspective was stll elusive,connecting the state-of-the-art developments based on the 2D Dirac plasmon-polaritons.Here,we review recent works on graphene and three-dimensional(3D)topological insulator(TI)plasmon-polariton,where the mid-IR and terahertz(THz)radiation experiences prominent confinement into a deep-subwavelength scale in a novel optoelectronic structure.After presenting general light-matter interactions between 2D Dirac plasmon and subwavelength quasiparticle excitations,we introduce various experimental techniques to couple the plasmonpolaritons with electromagnetic radiations.Electrical and optical controls over the plasmonic excitations reveal the hybridized plasmon modes in graphene and 3D Tl,demonstrating an intense near-field interaction of 2D Dirac plasmon within the highly-compressed volume.These findings can further be applied to invent optoelectronic biomolecular sensors,atomically thin photodetectors,and laser-driven light sources.
文摘A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.
基金We acknowledge that the research was supported by Key Team of Science and Technology Innovation of Zhejiang Province(No.2011R50029)College Talent Funds of Ningbo Institute of Technology,Zhejiang University(NO.1141257G1402)+2 种基金Ningbo Tackle Key Program for Agricultural Science and Technology Development(NO.2015C10014)Ningbo Natural Science Foundation(No.2014A610155&No.2011A610185)Zhejiang Provincial Natural Science Foundation of China(No.LQ13F010005).
文摘An experimental platform was developed to investigate the effects of audible sound(20 Hz to 20 MHz)on plant growth promotion,which included a microcontroller-based embedded system for audible sound adjustment and analysis.The direct digital frequency synthesis(DDFS)method was used to generate various waveforms of sound in the platform.Soundproof glass and mufflers were used to reduce background noise.The developed system was tested on various plants,including hydroponic tomatoes,celery and mung bean.The testing results showed that the developed platform could produce pure tone and mixing audible sound with high stability and accuracy,make octave analysis of the sound under experimental environments,and the background noise in the testing chamber of the platform was lower than 55 dB(A)when the compression engine was working.The developed experimental platform has a great potential on facilitating scientific research on acoustic biology effects on plants and collecting real-time experimental data.
