A novel super-junction lateral double-diffused metal-oxide semiconductor （SJ-LDMOS） with a partial lightly doped P pillar （PD） is proposed. Firstly, the reduction in the partial P pillar charges ensures the charge...A novel super-junction lateral double-diffused metal-oxide semiconductor （SJ-LDMOS） with a partial lightly doped P pillar （PD） is proposed. Firstly, the reduction in the partial P pillar charges ensures the charge balance and suppresses the substrate-assisted depletion effect. Secondly, the new electric field peak produced by the P/P junction modulates the surface electric field distribution. Both of these result in a high breakdown voltage （BV）. In addition, due to the same conduction paths, the specific on-resistance （Ron,sp） of the PD SJ-LDMOS is approximately identical to the conventional SJ-LDMOS. Simulation results indicate that the average value of the surface lateral electric field of the PD SJ-LDMOS reaches 20 V/μm at a 15 μm drift length, resulting in a BV of 300 V.展开更多
Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are ch...Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.展开更多
A series of multiphase metal-oxide catalysts(MnOx/γ-Al_(2)O_(3),CuOx/γ-Al_(2)O_(3),FeO_(x/γ)-Al_(2)O_(3),CeO_(x)/γ-Al_(2)O_(3)and LaOx/γ-Al_(2)O_(3))were prepared for plasma-catalyst degradation of multicomponent...A series of multiphase metal-oxide catalysts(MnOx/γ-Al_(2)O_(3),CuOx/γ-Al_(2)O_(3),FeO_(x/γ)-Al_(2)O_(3),CeO_(x)/γ-Al_(2)O_(3)and LaOx/γ-Al_(2)O_(3))were prepared for plasma-catalyst degradation of multicomponent volatile organic compounds(VOCs,such as toluene,acetone and ethyl acetate).The results reveal that the degradation efficiency(DE)of acetone,toluene and ethyl acetate in the DDBD system can be arranged as follows:Mn_(2)O_(3)/γ-Al_(2)O_(3)>Fe2O3/γ-Al_(2)O_(3)>CuO_(/γ)-Al_(2)O_(3)>CeO_(2)/γ-Al_(2)O_(3)>La_(2)O_(3)/γ-Al_(2)O_(3)>γ-Al_(2)O_(3),and the highest DE(49.5%for acetone,93.3%for toluene and 79.8%for ethyl acetate)is obtained in Mn_(2)O_(3)/γ-Al_(2)O_(3)+double dielectric barrier discharge(DDBD)system at specific input energy(SIE)of 700 J/L.Compared with the other catalysts,Mn_(2)O_(3)/γ-Al_(2)O_(3)also exhibits the most significant inhibitory effect on the production of ozone(O3).On the other hand,CeO_(2)/γ-Al_(2)O_(3)and La_(2)O_(3)/γ-Al_(2)O_(3)catalysts display different catalytic selectivity.Both catalysts can slightly raise the DE of VOCs and remarkably facilitate VOCs’mineralization.The carbon balance(CB)is increased by 30.2%and 38.8%,and the CO_(2)selectivity(SCO_(2))is raised by 70.5%and 11.9%in the CeO_(2)/γ-Al_(2)O_(3)+DDBD system and La_(2)O_(3)/γ-Al_(2)O_(3)+DDBD system at SIE of 700 J/L,respectively.To further understand the catalytic effect of the catalysts,the adsorption of O3on different catalysts was simulated by a DFT model.According to the results of the DFT model,it is found that the adsorption energy of other metal oxides seems to be used as a reference for catalytic effect to a certain extent except CeO_(2).The higher the absolute values of adsorption energy,the higher the improvement of VOCs degradation efficiency by catalyst.展开更多
This paper presents a numerical study on the simultaneous reconstruction of temperature and volume fraction fields of soot and metal-oxide nanoparticles in an axisymmetric nanofluid fuel sooting flame based on the rad...This paper presents a numerical study on the simultaneous reconstruction of temperature and volume fraction fields of soot and metal-oxide nanoparticles in an axisymmetric nanofluid fuel sooting flame based on the radiative energy images captured by a charge-coupled device(CCD)camera.The least squares QR decomposition method was introduced to deal with the reconstruction inverse problem.The effects of ray numbers and measurement errors on the reconstruction accuracy were investigated.It was found that the reconstruction accuracies for volume fraction fields of soot and metaloxide nanoparticles were easily affected by the measurement errors for radiation intensity,whereas only the metal-oxide volume fraction field reconstruction was more sensitive to the measurement error for the volume fraction ratio of metaloxide nanoparticles to soot.The results show that the temperature,soot volume fraction,and metal-oxide nanoparticles volume fraction fields can be simultaneously and accurately retrieved for exact and noisy data using a single CCD camera.展开更多
Nanoclusters(NCs)have been demonstrated of outstanding performance in electrochemical energy storage and conversion technologies due to their strong quantum confinement effects and strong interaction with supports.Her...Nanoclusters(NCs)have been demonstrated of outstanding performance in electrochemical energy storage and conversion technologies due to their strong quantum confinement effects and strong interaction with supports.Here,we developed a class of ultrafine metal-oxide(MOx,M=Fe,Co and Ni)NCs incorporated with iron phthalocyanine(FePc),MOx/FePc-G,supported on graphene as high-performance catalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and carbon dioxide reduction(CO2RR).The high activities for ORR and OER are attributed to the electron donation and accepting ability of the highly redox active of FePc-G that could tune the properties of MOx.The FeOx/FePc-G exhibits an extremely positive half-wave potential(E1/2)of 0.888 and 0.610 V for ORR in alkaline and neutral conditions,respectively,which is around 60 mV more positive than that of Pt/C.And NiOx/FePc-G shows similar OER activity with the state-of-the-art catalysts,Ir/C,and better performance than NiFeO NCs supported on graphene.Remarkably,the CoOx/FePc-G and NiOx/FePc-G show high activity and selectivity to reduce CO2 into CO with a low onset potential of-0.22 V(overpotential is 0.11 V).展开更多
Elecrochemical CO_(2) reduction is a promising route to convert CO_(2) into the value added chemicals,and to control the increasing accumulation of 002 in the atmosphere.The CO_(2) molecule is stable and chemically in...Elecrochemical CO_(2) reduction is a promising route to convert CO_(2) into the value added chemicals,and to control the increasing accumulation of 002 in the atmosphere.The CO_(2) molecule is stable and chemically inert,so a highly efficient electrocatalyst is required for CO_(2) reduction.The single atoms with metal oxdde support is a new fronder in CO_(2) reduction.The supported single atoms contain disperse isolated atoms with an appropriate support maxcimize the atom efficiency of metals for boosting the catalytc perfomance.In this review,we had discussed state-of-the-art research on the synthestis of single atoms supported on the metal oxdde for boosting catalytic activity for CO_(2) reduction and special emphasis is placed on the influence of single atoms supported on metal oxdde on the CO_(2) reduction.Futhermore,we had discussed the challenges,and opportunities for paving the development of single atoms with metal support and their application in ecrocatalytic CO_(2) reduction.展开更多
Artificial synapses utilizing spike signals are essential elements of new generation brain-inspired computers.In this paper,we realize light-stimulated adaptive artificial synapse based on nanocrystalline zinc oxide f...Artificial synapses utilizing spike signals are essential elements of new generation brain-inspired computers.In this paper,we realize light-stimulated adaptive artificial synapse based on nanocrystalline zinc oxide film.The artificial synapse photoconductivity shows spike-type signal response,long and short-term memory(LTM and STM),STM-to-LTM transition and paired-pulse facilitation.It is also retaining the memory of previous exposures and demonstrates spike-frequency adaptation properties.A way to implement neurons with synaptic depression,tonic excitation,and delayed accelerating types of response under the influence of repetitive light signals is discussed.The developed artificial synapse is able to become a key element of neuromorphic chips and neuromorphic sensorics systems.展开更多
The surge arrester with excellent protection characteristics would decrease the overvoltage level ap- plied on the power apparatus to reduce their insulation levels and manufacturing bottleneck. The arrester for the 1...The surge arrester with excellent protection characteristics would decrease the overvoltage level ap- plied on the power apparatus to reduce their insulation levels and manufacturing bottleneck. The arrester for the 1000-kV ultra-high voltage ac power transmission system is designed as tank-type structure. The field-circuit combination numerical method combining the three-dimensional finite element method with circuit is proposed to analyze the potential distribution of GIS arrester. By comparing several design schemes, the most effective method to improve the potential distribution along the varistor column is to increase the voltage gradient of the ZnO varistor. Synthesizing several influential factors, the suitable voltage gradient of ZnO varistor should be controlled to 435 V/mm, and the resulted nonuniform degree of the potential distribution along the varistor column inside the GIS arrester would be controlled smaller than 10%. The result in this paper provides the fundamental technical index for the study of the high voltage gradient ZnO varistors.展开更多
With the growing applications of nanofluid flame, the monitoring and controlling of its combustion process is of paramount importance. Thus, it is necessary to develop diagnosing methods which can simultaneously image...With the growing applications of nanofluid flame, the monitoring and controlling of its combustion process is of paramount importance. Thus, it is necessary to develop diagnosing methods which can simultaneously image important parameters such as temperature and volume fractions of soot, metal-oxide nanoparticles. Tomographic emission spectroscopy is an effective method which has been proposed for this purpose. However, the inversion process was only reported with least-squares QR decomposition(LSQR) so far and there are numerous well-established reconstruction algorithms which have not been utilized yet.Thus, this work aims to perform systematic comparative studies on several representative algorithms for the inversion process. In the simulative studies, algorithms including Tikhonov regularization, algebraic reconstruction technique(ART), LSQR,Landweber algorithm, maximum likelihood expectation maximization(MLEM), and ordered subset expectation maximization(OSEM) were discussed. The effects of the number of iterations, the signal-to-noise ratio, and the number of projections and the calibration error in projection angles on the performance of the algorithms were investigated. Advice on selecting the suitable algorithms under different application conditions is then provided according to the extensive numerical studies.展开更多
Aligned carbon nanotube films coated with amorphous carbon were developed into novel templates by atomic layer deposition. Freestanding macroscopic metal-oxide nanotube films were then successfully synthesized by usin...Aligned carbon nanotube films coated with amorphous carbon were developed into novel templates by atomic layer deposition. Freestanding macroscopic metal-oxide nanotube films were then successfully synthesized by using these templates. The reactive amorphous carbon layer greatly improved the nuclei density, which ensured the high quality of the films and allowed for precise control of the wall thickness of the nanotubes. Using template-synthesized alumina nanotube films, we demonstrate a humidity sensor with a high response speed, a transmission electron microscopy （TEM） grid, and a catalyst support. The cross- stacked assembly, ultrathin thickness, chemical inertness, and high thermal stability of the alumina nanotube films contributed to the excellent performance of these devices. In addition, it is expected that the metal-oxide nanotube films would have significant potential owing to their material richness, macroscopic appearance, flexibility, compatibility with the semiconducting technologies, and the feasibility of mass production.展开更多
The ammonia decomposition for the production of carbon-free hydrogen has triggered great attention yet still remains challenging due to its sluggish kinetics,posting the importance of precise design of efficient catal...The ammonia decomposition for the production of carbon-free hydrogen has triggered great attention yet still remains challenging due to its sluggish kinetics,posting the importance of precise design of efficient catalysts for ammonia decomposition under low temperatures.Constructing the metal-support interaction and interface is one of the most important strategies for promoting catalysts.In this work,by coating ceria onto the Ni nanoparticles(NPs),we discover that the Ni-CeO_(2)interfaces create an exceptional effect to enhance the catalytic decomposition of ammonia by over 10 folds,compared with the pristine Ni.The kinetic analysis demonstrates that the recombinative N2 desorption is the rate-determining step(RDS)and the Ni-CeO_(2)interface greatly increases the RDS.Based on these understandings,a strategy to fabricate the Ni/CeO_(2)catalyst with abundant Ni-Ce-O interfaces via one-pot sol-gel method was employed(hereafter denoted to s-Ni/CeO_(2)).The s-Ni/CeO_(2)catalyst shows a high activity for ammonia decomposition,achieving a H_(2)formation rate of 10.5 mmol gcat1 min^(-1)at 550℃.Combined with a series of characterizations,the relationship between the catalyst structure and the performance was investigated for further understanding the effect of metal-oxide interfaces.展开更多
Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil en...Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil energies,while such a process is limited by chemical inertia and thermal stability of the CO_(2) molecule and complex hydrogenation routes.In this review,we first summarized the recent progresses of metal-oxide nanocatalysts considered as a category of the most promising catalysts in CO_(2) hydrogenation to value-added C1 chemicals including CH_(4)/CO,formic acid/formate,and methanol.These studies involve with different structural factors affecting the metal-oxide interfacial catalysis including the structures of both the metals(type,particle size,morphology/crystal plane,and bimetal alloy)and the supports(type,particle size,crystal phase,morphology/crystal plane,and composite)and their(strong)metal-support interactions so as to identify the key factor determining the reaction activity,product selectivity,and catalytic stability in CO_(2) hydrogenation.Finally,we further discuss challenging coupling with future research opportunities for tunable interfacial catalysis of metal-oxide nanocatalysts in CO_(2) conversion.展开更多
The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydroge...The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/C03 O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation （CO ＋ 02 and CO ＋ NO） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/C03 O4/cordierite. The second support decreases the activity of Pd/Co3Oa/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of COA1204 formation.展开更多
The interface between metal nanoparticles(NPs)and support plays a vital role in catalysis because both electron and atom exchanges occur across the metal-support interface.However,the rational design of interfacial st...The interface between metal nanoparticles(NPs)and support plays a vital role in catalysis because both electron and atom exchanges occur across the metal-support interface.However,the rational design of interfacial structure facilitating the charge transfer between the neighboring parts remains a challenge.Herein,a guided nucleation strategy based on redox reaction between noble metal precursor and supportsurface is introduced to construct epitaxial interfaces between Pt NPs and CeO2 support.The Pt/CeO2 catalyst exhibits near room temperature catalytic activity for CO oxidation that is benefited from the well-defined interface structure facilitating charge transfer from CeO2 support to Pt NPs.Meanwhile,this general approach based on support-surface-induced-nucleation was successfully extended to synthesize Pd and Cu nanocatalysts on CeO2,demonstrating its universal and feasible characteristics.This work is an important step towards developing highly active supported metal catalysts by engineering their interfaces.展开更多
The Complementary Metal-Oxide Semiconductor(CMOS)image sensor is a critical component with the function of providing accurate positioning in many space application systems.Under long-time operation in space environmen...The Complementary Metal-Oxide Semiconductor(CMOS)image sensor is a critical component with the function of providing accurate positioning in many space application systems.Under long-time operation in space environments,there are radiation related degradation and var-ious uncertainties affecting the positioning accuracy of CMOS image sensors,which further leads to a reliability reduction of CMOS image sensors.Obviously,the reliability of CMOS image sensors is related to their specified function,degradation,and uncertainties;however,current research has not fully described this relationship.In this paper,a comprehensive approach to reliability modelling of CMOs image sensors is proposed based on the reliability science principles.Firstly,the perfor-mance margin modelling of centroid positioning accuracy is conducted.Then,the degradation model of CMOS image sensors is derived considering the dark current increase induced by the total ionizing dose effects.Finally,various uncertainties are analyzed and quantified,and the measure-ment equation of reliability is proposed.A case study of a CMOS image sensor is conducted to apply the proposed method,and the sensitivity analysis can provide suggestions for design and use of CMOS image sensors to ensure reliability.A simulation study is conducted to present the advantages oftheproposed comprehensive approach.展开更多
Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of tu...Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of turn-on voltage(VON),and dual-gate TFTs for acquiring sensor signals and modulating VON have been deployed to improve the robustness and performance of the systems in which they are deployed.Digital circuit building blocks based on fluorinated TFTs have been designed,fabricated,and characterized,which demonstrate the utility of the proposed low-temperature TFT technologies for implementing flexible electronic systems.The construction and characterization of an analog front-end system for the acquisition of bio-potential signals and an active-matrix sensor array for the acquisition of tactile images have been reported recently.展开更多
In this study we investigate the dynamic recovery effects in IRF9520 commercial p-channel power vertical double diffused metal-oxide semiconductor field-effect transistors（VDMOSFETs） subjected to negative bias tempe...In this study we investigate the dynamic recovery effects in IRF9520 commercial p-channel power vertical double diffused metal-oxide semiconductor field-effect transistors（VDMOSFETs） subjected to negative bias temperature（NBT）stressing under the particular pulsed bias. Particular values of the pulsed stress voltage frequency and duty cycle are chosen in order to analyze the recoverable and permanent components of stress-induced threshold voltage shift in detail. The results are discussed in terms of the mechanisms responsible for buildup of oxide charge and interface traps. The partial recovery during the low level of pulsed gate voltage is ascribed to the removal of recoverable component of degradation, i.e., to passivation/neutralization of shallow oxide traps that are not transformed into the deeper traps（permanent component）.Considering the value of characteristic time constant associated with complete removal of the recoverable component of degradation, it is shown that by selecting an appropriate combination of the frequency and duty cycle, the threshold voltage shifts induced under the pulsed negative bias temperature stress conditions can be significantly reduced, which may be utilized for improving the device lifetime in real application circuits.展开更多
The paper proposes a novel transceiver in physical layer for high-speed serial data link based upon Universal Serial Bus (USB) 2.0, comprising transmitter and receiver. In the design, transmitter contains pre-and-main...The paper proposes a novel transceiver in physical layer for high-speed serial data link based upon Universal Serial Bus (USB) 2.0, comprising transmitter and receiver. In the design, transmitter contains pre-and-main driver to satisfy slew rate of output data, receiver includes optimized topology to improve preci- sion of received data. The circuit simulation is based on Cadence’s spectre software and Taiwan Semiconduc- tor Manufacture Corporation’s library of 0.25μm mixed-signal Complementary Metal-Oxide Semiconductor (CMOS) model. The front and post-simulation results reveal that the transceiver designed can transmit and re- ceive high-speed data in 480Mbps, which is in agreement with USB2.0 specification. The chip of physi- cal-layer transceiver has been designed and implemented with 0.25μm standard CMOS technology.展开更多
The catalysts of three-dimensionally ordered macroporous(3 DOM)Al_(2)O_(3)-supported core-shell structured Pt@MnOx nanoparticles(3 DOM-Pt@MnO_(x)/Al_(2)O_(3))were successfully prepared by the gas bubbling-assisted mem...The catalysts of three-dimensionally ordered macroporous(3 DOM)Al_(2)O_(3)-supported core-shell structured Pt@MnOx nanoparticles(3 DOM-Pt@MnO_(x)/Al_(2)O_(3))were successfully prepared by the gas bubbling-assisted membrane reduction-precipitation(GBMR/P)method.Pt@MnO_(x)core-shell nanoparticles(NPs)are highly dispersed on the inner surface of 3 DOM-Al_(2)O_(3)support.Pt@MnOx/3 DOM-Al_(2)O_(3)catalysts,which combine both advantages of high-efficiency soot-catalyst contact by 3 DOM-Al_(2)O_(3)structure and the abundant active sites by the optimized Pt-MnO_(x)interface,exhibit high catalytic activities for soot combustion,and the catalytic activities are strongly dependent on the thickness of MnO_(x)shell.Among the catalysts,3 DOM-Pt@MnO_(x)/Al_(2)O_(3)-1 catalyst with optimized Pt-MnO_(x)interface shows the highest catalytic activity for soot combustion,i.e.,its values of T_(50)and S_(CO_(2))^(m) are 351℃and98.6%,respectively.The highest density of Pt-MnO_(x)active sites for adsorptio n-activation of gaseous O_(2)is responsible for enhancing catalytic activity for soot combustion.Pt@MnOx/3 DOM-Al_(2)O_(3)catalysts are promising to practical applications for the emission reduction of soot particles.展开更多
The resistive switching properties in amorphous Pr0.67Sr0.33MnO3 films deposited by pulsed laser deposition are investigated.Reproducible and bipolar counter-8-shape and 8-shape switching behaviours of Au/Pr0.67Sr0.33...The resistive switching properties in amorphous Pr0.67Sr0.33MnO3 films deposited by pulsed laser deposition are investigated.Reproducible and bipolar counter-8-shape and 8-shape switching behaviours of Au/Pr0.67Sr0.33MnO3 /F：SnO2 junctions are obtained at room temperature.Dramatically,the coexistence of two switching polarities could be reversibly adjusted by an applied voltage range.The results allocated those two switching types to areas of different defect densities beneath the same electrode.The migration of oxygen vacancies and the trapping effect of electrons under an applied electric field play an important role.An interface-effect-related resistance switching is proposed in an amorphous Pr0.67Sr0.33MnO3-based memory cell.展开更多
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2010ZX02201)the National Natural Science Foundation of China (Grant No. 61176069)the National Defense Pre-Research of China (Grant No. 51308020304)
文摘A novel super-junction lateral double-diffused metal-oxide semiconductor （SJ-LDMOS） with a partial lightly doped P pillar （PD） is proposed. Firstly, the reduction in the partial P pillar charges ensures the charge balance and suppresses the substrate-assisted depletion effect. Secondly, the new electric field peak produced by the P/P junction modulates the surface electric field distribution. Both of these result in a high breakdown voltage （BV）. In addition, due to the same conduction paths, the specific on-resistance （Ron,sp） of the PD SJ-LDMOS is approximately identical to the conventional SJ-LDMOS. Simulation results indicate that the average value of the surface lateral electric field of the PD SJ-LDMOS reaches 20 V/μm at a 15 μm drift length, resulting in a BV of 300 V.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61176092,61036003,and 60837001)the National Basic Research Program of China (Grant No. 2012CB933503)+1 种基金the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20110121110025)the Fundamental Research Funds for the Central Universities,China (Grant No. 2010121056)
文摘Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.
基金Project supported by the Fundamental Research Funds for the Central Universities(2232021G-10)。
文摘A series of multiphase metal-oxide catalysts(MnOx/γ-Al_(2)O_(3),CuOx/γ-Al_(2)O_(3),FeO_(x/γ)-Al_(2)O_(3),CeO_(x)/γ-Al_(2)O_(3)and LaOx/γ-Al_(2)O_(3))were prepared for plasma-catalyst degradation of multicomponent volatile organic compounds(VOCs,such as toluene,acetone and ethyl acetate).The results reveal that the degradation efficiency(DE)of acetone,toluene and ethyl acetate in the DDBD system can be arranged as follows:Mn_(2)O_(3)/γ-Al_(2)O_(3)>Fe2O3/γ-Al_(2)O_(3)>CuO_(/γ)-Al_(2)O_(3)>CeO_(2)/γ-Al_(2)O_(3)>La_(2)O_(3)/γ-Al_(2)O_(3)>γ-Al_(2)O_(3),and the highest DE(49.5%for acetone,93.3%for toluene and 79.8%for ethyl acetate)is obtained in Mn_(2)O_(3)/γ-Al_(2)O_(3)+double dielectric barrier discharge(DDBD)system at specific input energy(SIE)of 700 J/L.Compared with the other catalysts,Mn_(2)O_(3)/γ-Al_(2)O_(3)also exhibits the most significant inhibitory effect on the production of ozone(O3).On the other hand,CeO_(2)/γ-Al_(2)O_(3)and La_(2)O_(3)/γ-Al_(2)O_(3)catalysts display different catalytic selectivity.Both catalysts can slightly raise the DE of VOCs and remarkably facilitate VOCs’mineralization.The carbon balance(CB)is increased by 30.2%and 38.8%,and the CO_(2)selectivity(SCO_(2))is raised by 70.5%and 11.9%in the CeO_(2)/γ-Al_(2)O_(3)+DDBD system and La_(2)O_(3)/γ-Al_(2)O_(3)+DDBD system at SIE of 700 J/L,respectively.To further understand the catalytic effect of the catalysts,the adsorption of O3on different catalysts was simulated by a DFT model.According to the results of the DFT model,it is found that the adsorption energy of other metal oxides seems to be used as a reference for catalytic effect to a certain extent except CeO_(2).The higher the absolute values of adsorption energy,the higher the improvement of VOCs degradation efficiency by catalyst.
基金Project supported by the National Natural Science Foundation of China(Grant No.51576100)the Project of"Six Talent Summit"of Jiangsu Province,China(Grant No.2014-XNY-002)
文摘This paper presents a numerical study on the simultaneous reconstruction of temperature and volume fraction fields of soot and metal-oxide nanoparticles in an axisymmetric nanofluid fuel sooting flame based on the radiative energy images captured by a charge-coupled device(CCD)camera.The least squares QR decomposition method was introduced to deal with the reconstruction inverse problem.The effects of ray numbers and measurement errors on the reconstruction accuracy were investigated.It was found that the reconstruction accuracies for volume fraction fields of soot and metaloxide nanoparticles were easily affected by the measurement errors for radiation intensity,whereas only the metal-oxide volume fraction field reconstruction was more sensitive to the measurement error for the volume fraction ratio of metaloxide nanoparticles to soot.The results show that the temperature,soot volume fraction,and metal-oxide nanoparticles volume fraction fields can be simultaneously and accurately retrieved for exact and noisy data using a single CCD camera.
基金supported by the Australian Research Council Discovery Project Funding Scheme(project number:DP180100568)
文摘Nanoclusters(NCs)have been demonstrated of outstanding performance in electrochemical energy storage and conversion technologies due to their strong quantum confinement effects and strong interaction with supports.Here,we developed a class of ultrafine metal-oxide(MOx,M=Fe,Co and Ni)NCs incorporated with iron phthalocyanine(FePc),MOx/FePc-G,supported on graphene as high-performance catalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and carbon dioxide reduction(CO2RR).The high activities for ORR and OER are attributed to the electron donation and accepting ability of the highly redox active of FePc-G that could tune the properties of MOx.The FeOx/FePc-G exhibits an extremely positive half-wave potential(E1/2)of 0.888 and 0.610 V for ORR in alkaline and neutral conditions,respectively,which is around 60 mV more positive than that of Pt/C.And NiOx/FePc-G shows similar OER activity with the state-of-the-art catalysts,Ir/C,and better performance than NiFeO NCs supported on graphene.Remarkably,the CoOx/FePc-G and NiOx/FePc-G show high activity and selectivity to reduce CO2 into CO with a low onset potential of-0.22 V(overpotential is 0.11 V).
基金This work was supported by China Postdoctoral Science Foundation under project number 2019M663054.
文摘Elecrochemical CO_(2) reduction is a promising route to convert CO_(2) into the value added chemicals,and to control the increasing accumulation of 002 in the atmosphere.The CO_(2) molecule is stable and chemically inert,so a highly efficient electrocatalyst is required for CO_(2) reduction.The single atoms with metal oxdde support is a new fronder in CO_(2) reduction.The supported single atoms contain disperse isolated atoms with an appropriate support maxcimize the atom efficiency of metals for boosting the catalytc perfomance.In this review,we had discussed state-of-the-art research on the synthestis of single atoms supported on the metal oxdde for boosting catalytic activity for CO_(2) reduction and special emphasis is placed on the influence of single atoms supported on metal oxdde on the CO_(2) reduction.Futhermore,we had discussed the challenges,and opportunities for paving the development of single atoms with metal support and their application in ecrocatalytic CO_(2) reduction.
基金supported by the Ministry of Science and Higher Education of the Russian Federation (Grant№075-15-2020-801)by Non-commercial Foundation for support of Science and Education 《INTELLECT》.
文摘Artificial synapses utilizing spike signals are essential elements of new generation brain-inspired computers.In this paper,we realize light-stimulated adaptive artificial synapse based on nanocrystalline zinc oxide film.The artificial synapse photoconductivity shows spike-type signal response,long and short-term memory(LTM and STM),STM-to-LTM transition and paired-pulse facilitation.It is also retaining the memory of previous exposures and demonstrates spike-frequency adaptation properties.A way to implement neurons with synaptic depression,tonic excitation,and delayed accelerating types of response under the influence of repetitive light signals is discussed.The developed artificial synapse is able to become a key element of neuromorphic chips and neuromorphic sensorics systems.
基金Supported by the National Nature Science Foundation of China (Grant Nos.50425721,5073001)the 11th Five-year National S&T Supporting Plan (Grant No.2006BAA02A16)
文摘The surge arrester with excellent protection characteristics would decrease the overvoltage level ap- plied on the power apparatus to reduce their insulation levels and manufacturing bottleneck. The arrester for the 1000-kV ultra-high voltage ac power transmission system is designed as tank-type structure. The field-circuit combination numerical method combining the three-dimensional finite element method with circuit is proposed to analyze the potential distribution of GIS arrester. By comparing several design schemes, the most effective method to improve the potential distribution along the varistor column is to increase the voltage gradient of the ZnO varistor. Synthesizing several influential factors, the suitable voltage gradient of ZnO varistor should be controlled to 435 V/mm, and the resulted nonuniform degree of the potential distribution along the varistor column inside the GIS arrester would be controlled smaller than 10%. The result in this paper provides the fundamental technical index for the study of the high voltage gradient ZnO varistors.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51706141 and 51976122)。
文摘With the growing applications of nanofluid flame, the monitoring and controlling of its combustion process is of paramount importance. Thus, it is necessary to develop diagnosing methods which can simultaneously image important parameters such as temperature and volume fractions of soot, metal-oxide nanoparticles. Tomographic emission spectroscopy is an effective method which has been proposed for this purpose. However, the inversion process was only reported with least-squares QR decomposition(LSQR) so far and there are numerous well-established reconstruction algorithms which have not been utilized yet.Thus, this work aims to perform systematic comparative studies on several representative algorithms for the inversion process. In the simulative studies, algorithms including Tikhonov regularization, algebraic reconstruction technique(ART), LSQR,Landweber algorithm, maximum likelihood expectation maximization(MLEM), and ordered subset expectation maximization(OSEM) were discussed. The effects of the number of iterations, the signal-to-noise ratio, and the number of projections and the calibration error in projection angles on the performance of the algorithms were investigated. Advice on selecting the suitable algorithms under different application conditions is then provided according to the extensive numerical studies.
基金This work was supported by the National Basic Research Program of China （No. 2012CB932301）, the National Natural Science Foundation of China （Nos. 51472142, 51102147, and 51102144）, and the Chinese Postdoctoral Science Foundation （Nos. 2014M550701 and 2012M520261）.
文摘Aligned carbon nanotube films coated with amorphous carbon were developed into novel templates by atomic layer deposition. Freestanding macroscopic metal-oxide nanotube films were then successfully synthesized by using these templates. The reactive amorphous carbon layer greatly improved the nuclei density, which ensured the high quality of the films and allowed for precise control of the wall thickness of the nanotubes. Using template-synthesized alumina nanotube films, we demonstrate a humidity sensor with a high response speed, a transmission electron microscopy （TEM） grid, and a catalyst support. The cross- stacked assembly, ultrathin thickness, chemical inertness, and high thermal stability of the alumina nanotube films contributed to the excellent performance of these devices. In addition, it is expected that the metal-oxide nanotube films would have significant potential owing to their material richness, macroscopic appearance, flexibility, compatibility with the semiconducting technologies, and the feasibility of mass production.
基金supported by the National Key R&D Program of China(No.2022YFB4002401,2022YFB4003701)the National Natural Science Foundation of China(Nos.22178058,22308055)+2 种基金Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22221005)Natural Science Foundation of Fujian Province(2022J05027)the Talent Program of Fuzhou University(XRC-22036).
文摘The ammonia decomposition for the production of carbon-free hydrogen has triggered great attention yet still remains challenging due to its sluggish kinetics,posting the importance of precise design of efficient catalysts for ammonia decomposition under low temperatures.Constructing the metal-support interaction and interface is one of the most important strategies for promoting catalysts.In this work,by coating ceria onto the Ni nanoparticles(NPs),we discover that the Ni-CeO_(2)interfaces create an exceptional effect to enhance the catalytic decomposition of ammonia by over 10 folds,compared with the pristine Ni.The kinetic analysis demonstrates that the recombinative N2 desorption is the rate-determining step(RDS)and the Ni-CeO_(2)interface greatly increases the RDS.Based on these understandings,a strategy to fabricate the Ni/CeO_(2)catalyst with abundant Ni-Ce-O interfaces via one-pot sol-gel method was employed(hereafter denoted to s-Ni/CeO_(2)).The s-Ni/CeO_(2)catalyst shows a high activity for ammonia decomposition,achieving a H_(2)formation rate of 10.5 mmol gcat1 min^(-1)at 550℃.Combined with a series of characterizations,the relationship between the catalyst structure and the performance was investigated for further understanding the effect of metal-oxide interfaces.
基金National Natural Science Foundation of China,21773212,Zhenhua ZhangJinhua Industrial Key Project,20221080,Zhenhua Zhangself-designed scientific research project of Zhejiang Normal University,2021ZS0602,Zhenhua Zhang.
文摘Catalytic CO_(2) hydrogenation to valuable chemicals is an excellent approach to address the increasingly serious“greenhouse effect”caused by CO_(2) emission generated from the utilizations of nonrenewable fossil energies,while such a process is limited by chemical inertia and thermal stability of the CO_(2) molecule and complex hydrogenation routes.In this review,we first summarized the recent progresses of metal-oxide nanocatalysts considered as a category of the most promising catalysts in CO_(2) hydrogenation to value-added C1 chemicals including CH_(4)/CO,formic acid/formate,and methanol.These studies involve with different structural factors affecting the metal-oxide interfacial catalysis including the structures of both the metals(type,particle size,morphology/crystal plane,and bimetal alloy)and the supports(type,particle size,crystal phase,morphology/crystal plane,and composite)and their(strong)metal-support interactions so as to identify the key factor determining the reaction activity,product selectivity,and catalytic stability in CO_(2) hydrogenation.Finally,we further discuss challenging coupling with future research opportunities for tunable interfacial catalysis of metal-oxide nanocatalysts in CO_(2) conversion.
基金supported by the National Specific-Purpose Scientific and Technical Program of Ukraine "Nanotechnology and Nanomaterials" (No.0110U005685)the Program of National Academy of Sciences of Ukraine "Fundamental Problems of Nanos-tructure Systems, Nanomaterials, Nanotechnologies" (No.KPKV 6541030)
文摘The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/C03 O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation （CO ＋ 02 and CO ＋ NO） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/C03 O4/cordierite. The second support decreases the activity of Pd/Co3Oa/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of COA1204 formation.
基金supported by the National Natural Science Foundation of China(Nos.51771047,51525101,U1602275,51601119)the Fundamental Research Funds for the Central Universities(N180204014)+1 种基金the Key Lab for ATM of Northeastern University(China)the Natural Science Foundation of Shenzhen University(No.2019006).
文摘The interface between metal nanoparticles(NPs)and support plays a vital role in catalysis because both electron and atom exchanges occur across the metal-support interface.However,the rational design of interfacial structure facilitating the charge transfer between the neighboring parts remains a challenge.Herein,a guided nucleation strategy based on redox reaction between noble metal precursor and supportsurface is introduced to construct epitaxial interfaces between Pt NPs and CeO2 support.The Pt/CeO2 catalyst exhibits near room temperature catalytic activity for CO oxidation that is benefited from the well-defined interface structure facilitating charge transfer from CeO2 support to Pt NPs.Meanwhile,this general approach based on support-surface-induced-nucleation was successfully extended to synthesize Pd and Cu nanocatalysts on CeO2,demonstrating its universal and feasible characteristics.This work is an important step towards developing highly active supported metal catalysts by engineering their interfaces.
基金the National Natural Science Foundation of China (No.51775020)the Science Challenge Project,China (No.TZ2018007)+1 种基金the National Natural Science Foundation of China (No.62073009)the Fundamental Research Funds for Central Universities,China (No.YWF-19-BJ-J-515).
文摘The Complementary Metal-Oxide Semiconductor(CMOS)image sensor is a critical component with the function of providing accurate positioning in many space application systems.Under long-time operation in space environments,there are radiation related degradation and var-ious uncertainties affecting the positioning accuracy of CMOS image sensors,which further leads to a reliability reduction of CMOS image sensors.Obviously,the reliability of CMOS image sensors is related to their specified function,degradation,and uncertainties;however,current research has not fully described this relationship.In this paper,a comprehensive approach to reliability modelling of CMOs image sensors is proposed based on the reliability science principles.Firstly,the perfor-mance margin modelling of centroid positioning accuracy is conducted.Then,the degradation model of CMOS image sensors is derived considering the dark current increase induced by the total ionizing dose effects.Finally,various uncertainties are analyzed and quantified,and the measure-ment equation of reliability is proposed.A case study of a CMOS image sensor is conducted to apply the proposed method,and the sensitivity analysis can provide suggestions for design and use of CMOS image sensors to ensure reliability.A simulation study is conducted to present the advantages oftheproposed comprehensive approach.
基金supported by Grant RGC 16215720 from the Science and Technology Program of Shenzhen under JCYJ20200109140601691Grant GHP/018/21SZ from the Innovation and Technology Fund+1 种基金Grant SGDX20211123145404006 from the Science and Technology Program of ShenzhenFundamental and Applied Fundamental Research Fund of Guangdong Province 2021B1515130001。
文摘Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of turn-on voltage(VON),and dual-gate TFTs for acquiring sensor signals and modulating VON have been deployed to improve the robustness and performance of the systems in which they are deployed.Digital circuit building blocks based on fluorinated TFTs have been designed,fabricated,and characterized,which demonstrate the utility of the proposed low-temperature TFT technologies for implementing flexible electronic systems.The construction and characterization of an analog front-end system for the acquisition of bio-potential signals and an active-matrix sensor array for the acquisition of tactile images have been reported recently.
基金Project supported by the Fund from the Ministry of Education,Science and Technological Development of the Republic of Serbia(Grant Nos.OI-171026 and TR-32026)the Ei PCB Factory,Ni
文摘In this study we investigate the dynamic recovery effects in IRF9520 commercial p-channel power vertical double diffused metal-oxide semiconductor field-effect transistors（VDMOSFETs） subjected to negative bias temperature（NBT）stressing under the particular pulsed bias. Particular values of the pulsed stress voltage frequency and duty cycle are chosen in order to analyze the recoverable and permanent components of stress-induced threshold voltage shift in detail. The results are discussed in terms of the mechanisms responsible for buildup of oxide charge and interface traps. The partial recovery during the low level of pulsed gate voltage is ascribed to the removal of recoverable component of degradation, i.e., to passivation/neutralization of shallow oxide traps that are not transformed into the deeper traps（permanent component）.Considering the value of characteristic time constant associated with complete removal of the recoverable component of degradation, it is shown that by selecting an appropriate combination of the frequency and duty cycle, the threshold voltage shifts induced under the pulsed negative bias temperature stress conditions can be significantly reduced, which may be utilized for improving the device lifetime in real application circuits.
文摘The paper proposes a novel transceiver in physical layer for high-speed serial data link based upon Universal Serial Bus (USB) 2.0, comprising transmitter and receiver. In the design, transmitter contains pre-and-main driver to satisfy slew rate of output data, receiver includes optimized topology to improve preci- sion of received data. The circuit simulation is based on Cadence’s spectre software and Taiwan Semiconduc- tor Manufacture Corporation’s library of 0.25μm mixed-signal Complementary Metal-Oxide Semiconductor (CMOS) model. The front and post-simulation results reveal that the transceiver designed can transmit and re- ceive high-speed data in 480Mbps, which is in agreement with USB2.0 specification. The chip of physi- cal-layer transceiver has been designed and implemented with 0.25μm standard CMOS technology.
基金supported by the National Natural Science Foundation of China(Nos.21673142,21972166)Beijing Natural Science Foundation(No.2202045)+2 种基金National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2017A05)PetroChina Innovation Foundation(No.2018D-5007-0505)Science Foundation of China University of Petroleum,Beijing(No.242017QNXZ02)。
文摘The catalysts of three-dimensionally ordered macroporous(3 DOM)Al_(2)O_(3)-supported core-shell structured Pt@MnOx nanoparticles(3 DOM-Pt@MnO_(x)/Al_(2)O_(3))were successfully prepared by the gas bubbling-assisted membrane reduction-precipitation(GBMR/P)method.Pt@MnO_(x)core-shell nanoparticles(NPs)are highly dispersed on the inner surface of 3 DOM-Al_(2)O_(3)support.Pt@MnOx/3 DOM-Al_(2)O_(3)catalysts,which combine both advantages of high-efficiency soot-catalyst contact by 3 DOM-Al_(2)O_(3)structure and the abundant active sites by the optimized Pt-MnO_(x)interface,exhibit high catalytic activities for soot combustion,and the catalytic activities are strongly dependent on the thickness of MnO_(x)shell.Among the catalysts,3 DOM-Pt@MnO_(x)/Al_(2)O_(3)-1 catalyst with optimized Pt-MnO_(x)interface shows the highest catalytic activity for soot combustion,i.e.,its values of T_(50)and S_(CO_(2))^(m) are 351℃and98.6%,respectively.The highest density of Pt-MnO_(x)active sites for adsorptio n-activation of gaseous O_(2)is responsible for enhancing catalytic activity for soot combustion.Pt@MnOx/3 DOM-Al_(2)O_(3)catalysts are promising to practical applications for the emission reduction of soot particles.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60976016)the Program for Innovative Research Team in Science and Technology in University of Henan Province (IRTSTUHN),China (Grant No. 2012IRTSTHN004)the Foundation Co-established by the Province and the Ministry in Henan University,China (Grant No. SBGJ090503)
文摘The resistive switching properties in amorphous Pr0.67Sr0.33MnO3 films deposited by pulsed laser deposition are investigated.Reproducible and bipolar counter-8-shape and 8-shape switching behaviours of Au/Pr0.67Sr0.33MnO3 /F：SnO2 junctions are obtained at room temperature.Dramatically,the coexistence of two switching polarities could be reversibly adjusted by an applied voltage range.The results allocated those two switching types to areas of different defect densities beneath the same electrode.The migration of oxygen vacancies and the trapping effect of electrons under an applied electric field play an important role.An interface-effect-related resistance switching is proposed in an amorphous Pr0.67Sr0.33MnO3-based memory cell.
