Cellulose-based materials have attracted growing interest in the development of advanced energy storage systems owing to their intrinsic sustainability,tunable physicochemical properties,and structural versatility.Thi...Cellulose-based materials have attracted growing interest in the development of advanced energy storage systems owing to their intrinsic sustainability,tunable physicochemical properties,and structural versatility.This review systematically summarizes the key features of cellulose from the perspectives of synthesis,physicochemical characteristics,and structural design,highlighting its unique functionality and adaptability.Furthermore,the roles of cellulose in four critical battery components,i.e.,electrode,solid electrolyte interphase,separator,and electrolyte,are comprehensively discussed,emphasizing the properties aligning with the specific requirements of each component.Finally,potential research directions are proposed to guide future development.This review provides a comprehensive framework for understanding the transformative potential of cellulose in sustainable electrochemical energy storage systems as well as a guideline for future studies.展开更多
The effect of Hf on the grain refinement of as-cast aluminum was investigated using optical microscopy, electron microscopy and X-ray diffraction. The result shows that the grain size of studied alloy decreases effect...The effect of Hf on the grain refinement of as-cast aluminum was investigated using optical microscopy, electron microscopy and X-ray diffraction. The result shows that the grain size of studied alloy decreases effectively with the addition of Hf,Hf can react with Al to form Al3Hf particles during the solidification, the primary Al3Hf particles are highly potent nucleants for Al and the nanoscale coherent Al3Hf particles can inhibit the grain growth by pinning effect. The grain refinement mechanism of studied alloys was verified by the solute theory and the crystallography study, and it can be divided into two distinct types: At low Hf contents, there are no primary Al3Hf phases to form, the acquired grain refinement is primarily attributed to the constitutional undercooling induced by the Hf solute. At medium and high Hf contents, both Hf solute and Al3Hf particles contribute to the refinement.展开更多
To meet the specification of the qubits in our laboratory,a 0.4 kA·cm^-2 superconducting rapid single flux quantum(RSFQ) circuit was designed and successfully fabricated with an improved Nb-based self-aligned lif...To meet the specification of the qubits in our laboratory,a 0.4 kA·cm^-2 superconducting rapid single flux quantum(RSFQ) circuit was designed and successfully fabricated with an improved Nb-based self-aligned lift-off process.This circuit consists of a single-fluxquantum(SFQ) pulse generator,a Josephson transmission line(JTL) and a T-flip flop(TFF),and it acts as a frequency divider.The values of the inductors in this circuit were extracted using InductEX and the basic function of this circuit was confirmed using the simulation software WRspice before fabrication.After fabrication,the basic parameters of this circuit were measured at ~2.5 K in a Janis He-3 cryostat.This work laid the theoretical and experimental basis for the future research on the RSFQqubit control circuits.展开更多
In this paper,a white organic light-emitting device(WOLEDs) with multiple-emissive-layer structure has been fabricated.The device has a simple structure of indium tin oxide(ITO)/NPB(20 nm)//DPVBi(20 nm)/CDBP:x Ir(btp)...In this paper,a white organic light-emitting device(WOLEDs) with multiple-emissive-layer structure has been fabricated.The device has a simple structure of indium tin oxide(ITO)/NPB(20 nm)//DPVBi(20 nm)/CDBP:x Ir(btp)2acac(10 nm)/Alq3(25 nm)/BCP(5 nm)/Cs F(1 nm)/Al(150 nm)(x= 0.15,2.5 and 3.0 wt%),where NPB and BCP are used as the hole-injecting layer,electron transporting and hole blocking layer,respectively.White light emission was realized in an OLED with 2.5% Ir(btp)2acac doping concentration.The device exhibits peak efficiency of 1.93 cd/A at 9 V and maximum brightness of 7005 cd/m^2 at 14 V.The Commission International de I'Eclairage(CIE)(1931) coordinates of white emission are well within the white zone,which moves from(0.35,0.33) to(0.26,0.30) when the applied voltage is varied from 5 V to 14 V.展开更多
Persistent luminescence nanoparticles(PLNPs)are a kind of phosphors that can remain luminescent for seconds to several days after the stoppage of excitation.Lanthanides show the special capability to largely broaden t...Persistent luminescence nanoparticles(PLNPs)are a kind of phosphors that can remain luminescent for seconds to several days after the stoppage of excitation.Lanthanides show the special capability to largely broaden the emission range and enhance the luminescence intensity of PLNPs due to their dense energy structure and unique electronic configurations.In the past decades,various methods have been developed for the synthesis of lanthanide-based PLNPs with excellent pe rsistent luminescence propertie s,and the lanthanide-based PLNPs are widely studied in areas including biome dicine,energy,and information storage.In this review,we summarized the research progress in the synthe sis of lanthanidebased PLNPs and outline d several typical synthesis methods.We discussed the fundamental concepts of preparation methods as well as the advantages and drawbacks of the typical synthetic approache s.Moreove r,the current challenges and the potential solutions for the development of lanthanide-based PLNP s are also discussed in an attempt to provide strate gies to further improve the optical properties of lanthanide-based PLNPs.We hope this review can contribute to the design of lanthanide-based PLNPs with desired properties and further promote their applications in biomedicine,energy,and information science.展开更多
We examine theoretically the performance of an Hg0.77Cd0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate.A rigoro...We examine theoretically the performance of an Hg0.77Cd0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate.A rigorous noise model of the receiver has been developed for this purpose.We calculate the total noise and sensitivity of the receiver.The front-end of the receiver exhibits a sensitivity of -45 dBm at a bit rate of 1 Gb/s and -30 dBm at a bit rate of 10 Gb/s,and the total mean-square noise curren t〈i2n〉=5×10-15 A2 at a bit rate of 1 Gb/s an d〈i2n〉 =10-12 A2 at a bit rate of 10 Gb/s,and a 3-dB bandwidth of 10 GHz.展开更多
The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and ...The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.展开更多
We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measure...We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.展开更多
We observe the Autler-Townes splitting effect in a △-type quantum three-level system, using the lowest three levels of a SQUID-type Al/AlOx/Al transmon qubit embedded in a three-dimensional copper microwave cavity. A...We observe the Autler-Townes splitting effect in a △-type quantum three-level system, using the lowest three levels of a SQUID-type Al/AlOx/Al transmon qubit embedded in a three-dimensional copper microwave cavity. A control tone at different strengths is applied in resonance with the transition between the first and second excited states, while the spectra between each of them and the ground state are probed by another microwave tone. The experimental result shows the difference between the two spectra, and fits well with the Lindblad master equation model.展开更多
The growth process of GeOx films formed by plasma post-oxidation （PPO） at room temperature （RT） is investigated using angle-resolved x-ray photoelectron spectroscopy （AR-XPS）. The experimental results show that ...The growth process of GeOx films formed by plasma post-oxidation （PPO） at room temperature （RT） is investigated using angle-resolved x-ray photoelectron spectroscopy （AR-XPS）. The experimental results show that the distributions of the Ge4＋ states, a mixture of the Ge^2＋ and Ge^3＋ states, and the Ge^1＋ states are localized from the GeOx surface to the GeOx/Ge interface. Moreover, the Ge^1＋ states are predominant when the two outermost layers of Ge atoms are oxidized. These findings are helpful for establishing in-depth knowledge of the growth mechanism of the GeOx layer and valuable for the optimization of Ge-based gate stacks for future complementary metal-oxide-semiconductor （MOS） field-effect transistor （CMOSFET） devices.展开更多
The present paper focused on the detection of methanol and propanol using Pd-gate metal-oxide-semiconductor （MOS） sensor. Surface mor- phology and composition of the gate film were studied by scanning electron micro...The present paper focused on the detection of methanol and propanol using Pd-gate metal-oxide-semiconductor （MOS） sensor. Surface mor- phology and composition of the gate film were studied by scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The response of the sensor for propanol and methanol was measured as shift in capacitance-voltage （C-V） and conductance-voltage （G-V） curves of the MOS structure. The sensitivity of the sensor towards methanol was found to be greater than that towards propanol. It was 58.2% for methanol and 32% for propanol （at 0.6 V, 1 MHz） in terms of capacitance measurements, while in terms of conductance results the sensitivity was found to be 57.2% for methanol and 38.9% for propanol at 1 kHz. The discontinuities or cracks present in the microstructure of the gate material are believed to be mainly responsible for the high sensitivity of the sensor, going with the decomposition of gas molecules and subsequent hydrogen permeation through Pd.展开更多
In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer （XRD） and scanning electron microscope （SEM）. Initially, SnO2 powder was derived u...In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer （XRD） and scanning electron microscope （SEM）. Initially, SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles. A suitable gas sensor structure was fabricated on 1′′×1′′ alumina substrate using thick film technology. The necessary paste for screen printing was also developed. SEM results showed sol-gel derived powder gets more agglomerated in the thick film form. The sensitivity of the sensor has been investigated at different temperatures （150 ？C？350 ？C） upon exposure to methanol, propanol and acetone, yielding a maximum at 250 ？C for acetone with 1 wt% PbO-doping while at 350 ？C for propanol with 3 wt% PbO-doping of the sensor. The reduction of particle size to nanometers （validated through XRD） leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors. The results also correlate well with the microstructural properties of the material and the dopant.展开更多
Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on gla...Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on glass substrate by thermal oxidation of preeposited zinc films using vacuum deposition technique. With applied voltage in the range from -3V to 3V, the contrast ratio, responsivity, and detectivity for an incident radiation of 0.1 mW at 365 nm wavelength were estimated. The proposed device exhibited a high gain which was attributed to the hole trapping at semiconductor-metal interface. I-V characteristics were studied and the parameters, such as ideality factor, leakage current, resistance-areaproduct, and barrier height, were extracted from the measured data.展开更多
The total quantum statistical entropy of Reissner-Nordstrom (RN) black holes is evaluated. The spacetime of the black holes is divided into three regions-region 1, (r > ro);region 2, (ro > r > ri);andregion 3...The total quantum statistical entropy of Reissner-Nordstrom (RN) black holes is evaluated. The spacetime of the black holes is divided into three regions-region 1, (r > ro);region 2, (ro > r > ri);andregion 3, (ri > r > 0)-where ro is the radius of the outer event horizon, and ri is the radius of the inner event horizon. The total quantum statistical entropy of RN black holes is S = S1 + S2 + Ss, where Si (i = 1, 2, 3) is the entropy, contributed by region Si (i = 1, 2, 3). The detailed calculation shows that S2 ≈ 0. S1 = (π^(2)/45)[kbAo/∈^(2)β^(3)], S3 = -(r2/45)[kbAi/∈^(2)β^(3)], where Ao and Ai are, respectively, the area of the outer and inner event horizons. Thus, as ri approaches ro, in the extreme case the total quantum statistical entropy of RN black holes approaches zero.展开更多
A generic numerical model of a long-wavelength Avalanche Photodiode （APD） based on narrow bandgap semiconductor InAsSb on InAs substrate is reported for the first time. This model has been applied for theoretical ch...A generic numerical model of a long-wavelength Avalanche Photodiode （APD） based on narrow bandgap semiconductor InAsSb on InAs substrate is reported for the first time. This model has been applied for theoretical characterization of a proposed N^＋ InAS/P-InAsSb avalanche photodiode structure for possible application in 2-5 μm wavelength region. The parameters such as gain, excess noise factor and their trade-off with variation of doping concentration and bias voltage have been estimated for the APD taking into account history-dependent theory of avalanche multiplication process, The LWIR APD is expected to fred application in optical gas sensor and in future generation of optical communication system.展开更多
This paper proposes a voice codification based on two algorithms that make the wave form codification in time domain. The first uses the significant impulse model (SIM), which has as a goal to operate as an endpoint d...This paper proposes a voice codification based on two algorithms that make the wave form codification in time domain. The first uses the significant impulse model (SIM), which has as a goal to operate as an endpoint detector and as a dawn sampling, through the detection and selection of the significant valleys and crests;the second algorithm, is a redundant wave-form recycler (RWR) that uses an architecture based on fuzzy logic with an accumulative memory. The fuzzy algorithm obtains the similitude grade between the redundant wave forms, this with the objective of save into an knowledge base the patterns, based on the no supervised learning and when there are into memory, automatically there will be used to identified their arrive respect to the input signal, substituting the input block by the correspondent pattern into memory. This decoding process is using the SIM interpolation with a memory in accordance to the RWR.展开更多
Transmission characteristics of single and double coplanar waveguide(CPW)resonators are simulated.The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature me...Transmission characteristics of single and double coplanar waveguide(CPW)resonators are simulated.The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature measurement results.The crosstalk behaves as exponential attenuation versus the distance between two resonators.展开更多
This paper presents a heuristic polarity decision-making algorithm for solving Boolean satisfiability （SAT）. The algorithm inherits many features of the current state-of-the-art SAT solvers, such as fast BCP, clause...This paper presents a heuristic polarity decision-making algorithm for solving Boolean satisfiability （SAT）. The algorithm inherits many features of the current state-of-the-art SAT solvers, such as fast BCP, clause recording, restarts, etc. In addition, a preconditioning step that calculates the polarities of variables according to the cover distribution of Karnaugh map is introduced into DPLL procedure, which greatly reduces the number of conflicts in the search process. The proposed approach is implemented as a SAT solver named DiffSat. Experiments show that DiffSat can solve many ＂real-life＂ instances in a reasonable time while the best existing SAT solvers, such as Zchaff and MiniSat, cannot. In particular, DiffSat can solve every instance of Bart benchmark suite in less than 0.03 s while Zchaff and MiniSat fail under a 900 s time limit. Furthermore, DiffSat even outperforms the outstanding incomplete algorithm DLM in some instances.展开更多
We successfully designed and fabricated TES bolometers utilizing Al/Ti bilayer TESs as sensitive thermometers.To reduce the intrinsic noise level and tune the saturation power of a bolometer,the TES thermometer is pla...We successfully designed and fabricated TES bolometers utilizing Al/Ti bilayer TESs as sensitive thermometers.To reduce the intrinsic noise level and tune the saturation power of a bolometer,the TES thermometer is placed on a suspended SiN platform which is thermally coupled to the heat bath by four long SiN beams with different geometries.The measurement results show that the detectors have background limited noise performance,with a low noise equivalent power(NEP)on the order of10-17W/Hz1/2and have a saturation power of several tens pW at a bath temperature of 320 mK.These detectors are suitable for applications in ground-based astrophysics experiments by integrating absorbers for specific wavelengths.展开更多
A novel low-loss 50-Ω coplanar waveguide with V-groove on an SOI substrate is proposed.Through a CMOS-compatible process and anisotropic etching of silicon, surface silicon is removed from the SOI.The measured result...A novel low-loss 50-Ω coplanar waveguide with V-groove on an SOI substrate is proposed.Through a CMOS-compatible process and anisotropic etching of silicon, surface silicon is removed from the SOI.The measured results show that the V-groove coplanar waveguide causes about 50% less loss than the conventional one at a high frequency of up to 40 GHz.展开更多
基金the funding support from University of Macao(Grant No.SRG2024-00034-IAPME)The Science and Technology Development Fund from Macao SAR(FDCT)(Grant No.0002/2024/TFP).
文摘Cellulose-based materials have attracted growing interest in the development of advanced energy storage systems owing to their intrinsic sustainability,tunable physicochemical properties,and structural versatility.This review systematically summarizes the key features of cellulose from the perspectives of synthesis,physicochemical characteristics,and structural design,highlighting its unique functionality and adaptability.Furthermore,the roles of cellulose in four critical battery components,i.e.,electrode,solid electrolyte interphase,separator,and electrolyte,are comprehensively discussed,emphasizing the properties aligning with the specific requirements of each component.Finally,potential research directions are proposed to guide future development.This review provides a comprehensive framework for understanding the transformative potential of cellulose in sustainable electrochemical energy storage systems as well as a guideline for future studies.
基金Project(SGRI-WD-71-13-001) supported by the Scientific and Technological Project of State Grid Corporation of China
文摘The effect of Hf on the grain refinement of as-cast aluminum was investigated using optical microscopy, electron microscopy and X-ray diffraction. The result shows that the grain size of studied alloy decreases effectively with the addition of Hf,Hf can react with Al to form Al3Hf particles during the solidification, the primary Al3Hf particles are highly potent nucleants for Al and the nanoscale coherent Al3Hf particles can inhibit the grain growth by pinning effect. The grain refinement mechanism of studied alloys was verified by the solute theory and the crystallography study, and it can be divided into two distinct types: At low Hf contents, there are no primary Al3Hf phases to form, the acquired grain refinement is primarily attributed to the constitutional undercooling induced by the Hf solute. At medium and high Hf contents, both Hf solute and Al3Hf particles contribute to the refinement.
基金financially supported by the Natural Science Foundation of China (No.60836001)the State Key Program for Basic Research of China (No.2011CBA00304)the Tsinghua University Initiative Scientific Research Program (No. 20131089314)
文摘To meet the specification of the qubits in our laboratory,a 0.4 kA·cm^-2 superconducting rapid single flux quantum(RSFQ) circuit was designed and successfully fabricated with an improved Nb-based self-aligned lift-off process.This circuit consists of a single-fluxquantum(SFQ) pulse generator,a Josephson transmission line(JTL) and a T-flip flop(TFF),and it acts as a frequency divider.The values of the inductors in this circuit were extracted using InductEX and the basic function of this circuit was confirmed using the simulation software WRspice before fabrication.After fabrication,the basic parameters of this circuit were measured at ~2.5 K in a Janis He-3 cryostat.This work laid the theoretical and experimental basis for the future research on the RSFQqubit control circuits.
文摘In this paper,a white organic light-emitting device(WOLEDs) with multiple-emissive-layer structure has been fabricated.The device has a simple structure of indium tin oxide(ITO)/NPB(20 nm)//DPVBi(20 nm)/CDBP:x Ir(btp)2acac(10 nm)/Alq3(25 nm)/BCP(5 nm)/Cs F(1 nm)/Al(150 nm)(x= 0.15,2.5 and 3.0 wt%),where NPB and BCP are used as the hole-injecting layer,electron transporting and hole blocking layer,respectively.White light emission was realized in an OLED with 2.5% Ir(btp)2acac doping concentration.The device exhibits peak efficiency of 1.93 cd/A at 9 V and maximum brightness of 7005 cd/m^2 at 14 V.The Commission International de I'Eclairage(CIE)(1931) coordinates of white emission are well within the white zone,which moves from(0.35,0.33) to(0.26,0.30) when the applied voltage is varied from 5 V to 14 V.
基金Project supported by the National Key R&D Program of China(2021YFA1202400,2017YFA0208000)the National Natural Science Foundation of China(21925401,21904033,51902177)the Fundamental Research Funds for the Central Universities(2042021 kf0036)。
文摘Persistent luminescence nanoparticles(PLNPs)are a kind of phosphors that can remain luminescent for seconds to several days after the stoppage of excitation.Lanthanides show the special capability to largely broaden the emission range and enhance the luminescence intensity of PLNPs due to their dense energy structure and unique electronic configurations.In the past decades,various methods have been developed for the synthesis of lanthanide-based PLNPs with excellent pe rsistent luminescence propertie s,and the lanthanide-based PLNPs are widely studied in areas including biome dicine,energy,and information storage.In this review,we summarized the research progress in the synthe sis of lanthanidebased PLNPs and outline d several typical synthesis methods.We discussed the fundamental concepts of preparation methods as well as the advantages and drawbacks of the typical synthetic approache s.Moreove r,the current challenges and the potential solutions for the development of lanthanide-based PLNP s are also discussed in an attempt to provide strate gies to further improve the optical properties of lanthanide-based PLNPs.We hope this review can contribute to the design of lanthanide-based PLNPs with desired properties and further promote their applications in biomedicine,energy,and information science.
文摘We examine theoretically the performance of an Hg0.77Cd0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate.A rigorous noise model of the receiver has been developed for this purpose.We calculate the total noise and sensitivity of the receiver.The front-end of the receiver exhibits a sensitivity of -45 dBm at a bit rate of 1 Gb/s and -30 dBm at a bit rate of 10 Gb/s,and the total mean-square noise curren t〈i2n〉=5×10-15 A2 at a bit rate of 1 Gb/s an d〈i2n〉 =10-12 A2 at a bit rate of 10 Gb/s,and a 3-dB bandwidth of 10 GHz.
基金the Office of R&D,National Cheng Kung University,Taiwan
文摘The performance of polymer light emitting devices(PLEDs)based on polyvinyl carbazole(PVK)is improved by introducing a nanoscale interfacial thin layer,made of poly(ethylene oxide)(PEO),between the calcium cathode and the PVK emissive layer.It is believed that the PEO layer plays a key role in enhancing the device performance.In comparison to the device with Ca/Al as the cathode,the performance of the PLED with PEO/Ca/Al cathode,including the driving voltage,luminance efficiency is significantly improved.These improvements are attributed to the introduction of a thin layer of PEO that can lower the interfacial barrier and facilitate electron injection.
基金supported by the National Basic Research Program of China(Grant No.2011CBA00304)Tsinghua University Initiative Scientific Research Program,China(Grant No.20131089314)the National Natural Science Foundation of China(Grant Nos.60836001 and 11273023)
文摘We report the optical response characteristics of A1/Ti bilayer transition edge sensors （TESs）, which are mainly comprised of A1/Ti bilayer thermometers and suspended SiN membranes for thermal isolation. The measurement was performed in a 3He sorption refrigerator and the device＇s response to optical pulses was investigated using a pulsed laser source. Based on these measurements, we obtained the effective recovery time （τeff） of the devices at different biases and discussed the dependence of Veff on the bias. The device with a 940 μm × 940 μm continuous suspended SiN membrane demonstrated a fast response speed with τeff = 3.9 μs, which indicates a high temperature sensitivity （a = T/R·dR/dT = 326）. The results also showed that the TES exhibits good linearity under optical pulses of variable widths.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00304,2014CB848700 and 2014CB921401
文摘We observe the Autler-Townes splitting effect in a △-type quantum three-level system, using the lowest three levels of a SQUID-type Al/AlOx/Al transmon qubit embedded in a three-dimensional copper microwave cavity. A control tone at different strengths is applied in resonance with the transition between the first and second excited states, while the spectra between each of them and the ground state are probed by another microwave tone. The experimental result shows the difference between the two spectra, and fits well with the Lindblad master equation model.
基金supported by the National Natural Science Foundation of China(Grant Nos.61574168 and 61504163)
文摘The growth process of GeOx films formed by plasma post-oxidation （PPO） at room temperature （RT） is investigated using angle-resolved x-ray photoelectron spectroscopy （AR-XPS）. The experimental results show that the distributions of the Ge4＋ states, a mixture of the Ge^2＋ and Ge^3＋ states, and the Ge^1＋ states are localized from the GeOx surface to the GeOx/Ge interface. Moreover, the Ge^1＋ states are predominant when the two outermost layers of Ge atoms are oxidized. These findings are helpful for establishing in-depth knowledge of the growth mechanism of the GeOx layer and valuable for the optimization of Ge-based gate stacks for future complementary metal-oxide-semiconductor （MOS） field-effect transistor （CMOSFET） devices.
文摘The present paper focused on the detection of methanol and propanol using Pd-gate metal-oxide-semiconductor （MOS） sensor. Surface mor- phology and composition of the gate film were studied by scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The response of the sensor for propanol and methanol was measured as shift in capacitance-voltage （C-V） and conductance-voltage （G-V） curves of the MOS structure. The sensitivity of the sensor towards methanol was found to be greater than that towards propanol. It was 58.2% for methanol and 32% for propanol （at 0.6 V, 1 MHz） in terms of capacitance measurements, while in terms of conductance results the sensitivity was found to be 57.2% for methanol and 38.9% for propanol at 1 kHz. The discontinuities or cracks present in the microstructure of the gate material are believed to be mainly responsible for the high sensitivity of the sensor, going with the decomposition of gas molecules and subsequent hydrogen permeation through Pd.
文摘In the present work the structural information of PbO-doped SnO2 thick film sensor has been investigated with X-ray diffractometer （XRD） and scanning electron microscope （SEM）. Initially, SnO2 powder was derived using sol-gel process and was subsequently doped with PbO and ground up to nanosized particles. A suitable gas sensor structure was fabricated on 1′′×1′′ alumina substrate using thick film technology. The necessary paste for screen printing was also developed. SEM results showed sol-gel derived powder gets more agglomerated in the thick film form. The sensitivity of the sensor has been investigated at different temperatures （150 ？C？350 ？C） upon exposure to methanol, propanol and acetone, yielding a maximum at 250 ？C for acetone with 1 wt% PbO-doping while at 350 ？C for propanol with 3 wt% PbO-doping of the sensor. The reduction of particle size to nanometers （validated through XRD） leads to a dramatic improvement in sensitivity of sensors for the chosen organic vapors. The results also correlate well with the microstructural properties of the material and the dopant.
基金support by Indo-Iraq Cultural Exchange Program of ICCR (Indian Council for Cultural Relations)
文摘Fabrication and characterization of metal-semiconductor-metal ultraviolet （MSM UV） photodetector based on ZnO ultra thin （nano scale） films with Pd Schottky contact are reported. The ZnO thin film was grown on glass substrate by thermal oxidation of preeposited zinc films using vacuum deposition technique. With applied voltage in the range from -3V to 3V, the contrast ratio, responsivity, and detectivity for an incident radiation of 0.1 mW at 365 nm wavelength were estimated. The proposed device exhibited a high gain which was attributed to the hole trapping at semiconductor-metal interface. I-V characteristics were studied and the parameters, such as ideality factor, leakage current, resistance-areaproduct, and barrier height, were extracted from the measured data.
文摘The total quantum statistical entropy of Reissner-Nordstrom (RN) black holes is evaluated. The spacetime of the black holes is divided into three regions-region 1, (r > ro);region 2, (ro > r > ri);andregion 3, (ri > r > 0)-where ro is the radius of the outer event horizon, and ri is the radius of the inner event horizon. The total quantum statistical entropy of RN black holes is S = S1 + S2 + Ss, where Si (i = 1, 2, 3) is the entropy, contributed by region Si (i = 1, 2, 3). The detailed calculation shows that S2 ≈ 0. S1 = (π^(2)/45)[kbAo/∈^(2)β^(3)], S3 = -(r2/45)[kbAi/∈^(2)β^(3)], where Ao and Ai are, respectively, the area of the outer and inner event horizons. Thus, as ri approaches ro, in the extreme case the total quantum statistical entropy of RN black holes approaches zero.
文摘A generic numerical model of a long-wavelength Avalanche Photodiode （APD） based on narrow bandgap semiconductor InAsSb on InAs substrate is reported for the first time. This model has been applied for theoretical characterization of a proposed N^＋ InAS/P-InAsSb avalanche photodiode structure for possible application in 2-5 μm wavelength region. The parameters such as gain, excess noise factor and their trade-off with variation of doping concentration and bias voltage have been estimated for the APD taking into account history-dependent theory of avalanche multiplication process, The LWIR APD is expected to fred application in optical gas sensor and in future generation of optical communication system.
文摘This paper proposes a voice codification based on two algorithms that make the wave form codification in time domain. The first uses the significant impulse model (SIM), which has as a goal to operate as an endpoint detector and as a dawn sampling, through the detection and selection of the significant valleys and crests;the second algorithm, is a redundant wave-form recycler (RWR) that uses an architecture based on fuzzy logic with an accumulative memory. The fuzzy algorithm obtains the similitude grade between the redundant wave forms, this with the objective of save into an knowledge base the patterns, based on the no supervised learning and when there are into memory, automatically there will be used to identified their arrive respect to the input signal, substituting the input block by the correspondent pattern into memory. This decoding process is using the SIM interpolation with a memory in accordance to the RWR.
基金Supported by the State Key Program for Basic Research of China under Grant No 2011CBA00304the National Natural Science Foundation of China(60836001).
文摘Transmission characteristics of single and double coplanar waveguide(CPW)resonators are simulated.The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature measurement results.The crosstalk behaves as exponential attenuation versus the distance between two resonators.
基金the National Natural Science Foundation of China (Grant Nos. 90207002, 90307017, 60773125 and 60676018)National Science Foundation (Grant Nos. CCR-0306298)+1 种基金China Postdoctoral Science Foundation (Grant No. KLH1202005)the Natural Science Foundation of Shanghai City (Grant No. 06ZR14016)
文摘This paper presents a heuristic polarity decision-making algorithm for solving Boolean satisfiability （SAT）. The algorithm inherits many features of the current state-of-the-art SAT solvers, such as fast BCP, clause recording, restarts, etc. In addition, a preconditioning step that calculates the polarities of variables according to the cover distribution of Karnaugh map is introduced into DPLL procedure, which greatly reduces the number of conflicts in the search process. The proposed approach is implemented as a SAT solver named DiffSat. Experiments show that DiffSat can solve many ＂real-life＂ instances in a reasonable time while the best existing SAT solvers, such as Zchaff and MiniSat, cannot. In particular, DiffSat can solve every instance of Bart benchmark suite in less than 0.03 s while Zchaff and MiniSat fail under a 900 s time limit. Furthermore, DiffSat even outperforms the outstanding incomplete algorithm DLM in some instances.
基金supported by the National Basic Research Program of China (2011CBA00304)Tsinghua University Initiative Scientific Research Program (20131089314) the National Natural Science Foundation of China (60836001 and 11273023)
文摘We successfully designed and fabricated TES bolometers utilizing Al/Ti bilayer TESs as sensitive thermometers.To reduce the intrinsic noise level and tune the saturation power of a bolometer,the TES thermometer is placed on a suspended SiN platform which is thermally coupled to the heat bath by four long SiN beams with different geometries.The measurement results show that the detectors have background limited noise performance,with a low noise equivalent power(NEP)on the order of10-17W/Hz1/2and have a saturation power of several tens pW at a bath temperature of 320 mK.These detectors are suitable for applications in ground-based astrophysics experiments by integrating absorbers for specific wavelengths.
基金supported by the Shanghai Science & Technology Committee(Nos.075007033, 07QB14018)
文摘A novel low-loss 50-Ω coplanar waveguide with V-groove on an SOI substrate is proposed.Through a CMOS-compatible process and anisotropic etching of silicon, surface silicon is removed from the SOI.The measured results show that the V-groove coplanar waveguide causes about 50% less loss than the conventional one at a high frequency of up to 40 GHz.
