The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have di...The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have difficulty reflecting practical con-ditions.This work demonstrated a multi-fingerβ-Ga_(2)O_(3) MOSFET with a maximum drain current of 0.5 A.Electrical characteris-tics were measured,and the heat dissipation of the device was investigated through infrared images.The relationship between device temperature and time/bias is analyzed.展开更多
A new self-heating effect model for 4H-SiC MESFETs is proposed based on a combination of an analytical and a computer aided design （CAD） oriented drain current model. The circuit oriented expressions of 4H-SiC low-f...A new self-heating effect model for 4H-SiC MESFETs is proposed based on a combination of an analytical and a computer aided design （CAD） oriented drain current model. The circuit oriented expressions of 4H-SiC low-field electron mobility and incomplete ionization rate, which are related to temperature, are presented in this model, which are used to estimate the self-heating effect of 4H-SiC MESFETs. The verification of the present model is made, and the good agreement between simulated results and measured data of DC I - V curves with the self-heating effect is obtained.展开更多
Dynamic self-heating effect(SHE)of silicon-on-insulator(SOI)MOSFET is comprehensively evaluated by ultrafast pulsed I-V measurement in this work.It is found for the first time that the SHE complete heating response an...Dynamic self-heating effect(SHE)of silicon-on-insulator(SOI)MOSFET is comprehensively evaluated by ultrafast pulsed I-V measurement in this work.It is found for the first time that the SHE complete heating response and cooling response of SOI MOSFETs are conjugated,with two-stage curves shown.We establish the effective thermal transient response model with stage superposition corresponding to the heating process.The systematic study of SHE dependence on workload shows that frequency and duty cycle have more significant effect on SHE in first-stage heating process than in the second stage.In the first-stage heating process,the peak lattice temperature and current oscillation amplitude decrease by more than 25 K and 4%with frequency increasing to 10 MHz,and when duty cycle is reduced to 25%,the peak lattice temperature drops to 306 K and current oscillation amplitude decreases to 0.77%.Finally,the investigation of two-stage(heating and cooling)process provides a guideline for the unified optimization of dynamic SHE in terms of workload.As the operating frequency is raised to GHz,the peak temperature depends on duty cycle,and self-heating oscillation is completely suppressed.展开更多
For exploiting advantages of electron beam air plasma in some unusual applications, a Monte Carlo （MC） model coupled with heat transfer model is established to simulate the characteristics of electron beam air plasm...For exploiting advantages of electron beam air plasma in some unusual applications, a Monte Carlo （MC） model coupled with heat transfer model is established to simulate the characteristics of electron beam air plasma by considering the self-heating effect. Based on the model, the electron beam induced temperature field and the related plasma properties are investigated. The results indicate that a nonuniform temperature field is formed in the electron beam plasma region and the average temperature is of the order of 600 K. Moreover, much larger volume pear-shaped electron beam plasma is produced in hot state rather than in cold state. The beam ranges can, with beam energies of 75 keV and 80 keV, exceed 1.0 m and 1.2 m in air at pressure of 100 torr, respectively. Finally, a well verified formula is obtained for calculating the range of high energy electron beam in atmosphere.展开更多
A thermal model of 4H-SiC MESFET is developed based on the temperature dependences of material parameters and three-region I - V model. The static current characteristics of 4H-SiC MESFET have been obtained with the c...A thermal model of 4H-SiC MESFET is developed based on the temperature dependences of material parameters and three-region I - V model. The static current characteristics of 4H-SiC MESFET have been obtained with the consideration of the self-heating effect on related parameters including electron mobility, saturation velocity and thermal conductivity. High voltage performances are analysed using equivalent thermal conductivity model. Using the physicalbased simulations, we studied the dependence of self-heating temperature on the thickness and doping of substrate. The obtained results can be used for optimization of the thermal design of the SiC-based high-power field effect transistors.展开更多
An inherent self-heating effect of the silicon-on-insulator (SOI) devices limits their application at high current levels. In this paper a novel solution to reduce the self-heating effect is proposed, based on N+ and ...An inherent self-heating effect of the silicon-on-insulator (SOI) devices limits their application at high current levels. In this paper a novel solution to reduce the self-heating effect is proposed, based on N+ and O+ co-implantation into silicon wafer to form a new buried layer structure. This new structure was simulated using Medici program, and the temperature distribution and output characteristics were compared with those of the conventional SOI counterparts. As expected, a reduction of self-heating effect in the novel SOI device was observed.展开更多
Compared with bulk-silicon technology, silicon-on-insulator (SOI) technology possesses many advan-tages but it is inevitable that the buried silicon dioxide layer also thermally insulates the metal – oxide – silicon...Compared with bulk-silicon technology, silicon-on-insulator (SOI) technology possesses many advan-tages but it is inevitable that the buried silicon dioxide layer also thermally insulates the metal – oxide – silicon field-effect transistors (MOSFETs) from the bulk due to the low thermal conductivity. One of the alternative insulator to replace the buried oxide layer is aluminum nitride (AlN), which has a thermal conductivity that is about 200 times higher than that of SiO2 (320 W·m ? 1·K? 1 versus 1.4 W·m? 1·K? 1). To investigate the self-heating effects of small-size MOSFETs fabricated on silicon-on-aluminum nitride (SOAN) substrate, a two-dimensional numerical analysis is performed by using a device simulator called MEDICI run on a Solaris workstation to simulate the electri-cal characteristics and temperature distribution by comparing with those of bulk and standard SOI MOSFETs. Our study suggests that AlN is a suitable alternative to silicon dioxide as a buried dielectric in SOI and expands the appli-cations of SOI to high temperature conditions.展开更多
We use an electro-thermal coupled Monte Carlo simulation framework to investigate the self-heating effect（SHE） in 14 nm bulk n Fin FETs with ambient temperature（TA） from 220 to 400 K. Based on this method, nonloca...We use an electro-thermal coupled Monte Carlo simulation framework to investigate the self-heating effect（SHE） in 14 nm bulk n Fin FETs with ambient temperature（TA） from 220 to 400 K. Based on this method, nonlocal heat generation can be achieved. Contact thermal resistances of Si/Metal and Si/Si O_2 are selected to ensure that the source and drain heat dissipation paths are the first two heat dissipation paths. The results are listed below：（i） not all input power（Q_（input） turns into heat generation in the device region and some is taken out by the thermal non-equilibrium carriers, owing to the serious non-equilibrium transport;（ii） a higher TA leads to a larger ratio of input power turning into heat generation in the device region at the same operating voltages;（iii） SHE can lead to serious degradation in the carrier transport, which will increase when TA increases;（iv） the current degradation can be 8.9% when Vds = 0.7 V, Vgs = 1 V and TA = 400 K;（v） device thermal resistance（Rth） increases with increasing of TA, which is seriously impacted by the non-equilibrium transport. Hence, the impact of TA should be carefully considered when investigating SHE in nanoscale devices.展开更多
To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator（SGOI） n-type metal-oxide-semiconductor field-effect transistors（nMOSFETs）,this paper proposes a novel device called double step b...To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator（SGOI） n-type metal-oxide-semiconductor field-effect transistors（nMOSFETs）,this paper proposes a novel device called double step buried oxide（BOX） SGOI,investigates its electrical and thermal characteristics,and analyzes the effect of self-heating on its electrical parameters.During the simulation of the device,a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from phonon boundary scattering is considered.A comparative study of SGOI nMOSFETs with different BOX thicknesses under channel and different channel strains has been performed.By reducing moderately the BOX thickness under the channel,the channel temperature caused by the self-heating effect can be effectively reduced.Moreover,mobility degradation,off state current and a short-channel effect such as drain induced barrier lowering can be well suppressed.Therefore,SGOI MOSFETs with a thinner BOX under the channel can improve the overall performance and long-term reliability efficiently.展开更多
Considering the self-heating effect, an accurate expression for the global interconnection resistance per unit length in terms of interconnection wire width and spacing is presented. Based on the proposed resistance m...Considering the self-heating effect, an accurate expression for the global interconnection resistance per unit length in terms of interconnection wire width and spacing is presented. Based on the proposed resistance model and according to the trade-off theory, a novel optimization analytical model of delay, power dissipation and bandwidth is derived. The proposed optimal model is verified and compared based on 90 nm, 65 nm and 40 nm CMOS technologies. It can be found that more optimum results can be easily obtained by the proposed model. This optimization model is more accurate and realistic than the conventional optimization models, and can be integrated into the global interconnection design ofnano-scale integrated circuits.展开更多
An analytical DC model accounting for the self-heating effect of polycrystalline silicon thin-film transistors（poly-Si TFTs） is presented.In deriving the model for the self-heating effect, the temperature dependence...An analytical DC model accounting for the self-heating effect of polycrystalline silicon thin-film transistors（poly-Si TFTs） is presented.In deriving the model for the self-heating effect, the temperature dependence of the effective mobility is studied in detail.Based on the mobility model and a first order approximation, a closed-form analytical drain current model considering the self-heating effect is derived.Compared with the available experimental data, the proposed model, which includes the self-heating and kink effects, provides an accurate description of the output characteristics over the linear, the saturation, and the kink regimes.展开更多
Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms lig...Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.展开更多
The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF...The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.展开更多
Agglomeration supports the high-quality development of the manufacturing industry,and its associated resource and environmental effects play a crucial role in driving green economic development.Based on data from pref...Agglomeration supports the high-quality development of the manufacturing industry,and its associated resource and environmental effects play a crucial role in driving green economic development.Based on data from prefecture-level cities in China from 2005 to 2019,this study employs the inverse distance weighting method,the bivariate local indicator of spatial association model,the spatial Durbin model,and other techniques to explore the relationship between manufacturing agglomeration and PM_(2.5)concentrations,and to assess the impact of its manufacturing agglomeration.Four correlation patterns are observed:high-high,low-low,high-low,and low-high.Among these,high-high and low-low patterns dominate in terms of number of cities.These correlation patterns demonstrate strong temporal stability,with a clear“Matthew effect”.The effect of manufacturing agglomeration on PM_(2.5)levels is significantly negative and helps reduce concentrations regionally,indicating the need to further enhance agglomeration levels regionally.However,it can increase PM_(2.5)levels in neighboring areas due to a siphon effect,and the impact of varies across regions.Compared with levels in 2005-2013,the significance of the relationship between manufacturing agglomeration and PM_(2.5)weakened in the 2013-2019 period.Accordingly,this study proposes countermeasures and policy recommendations aimed at strengthening regional collaborative governance and inspiring differentiated agglomeration strategies to support sustainable economic development in China.展开更多
Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticle...Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.展开更多
Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electro...Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.展开更多
The efficient electrocatalytic oxidation of glycerol(GLY)is one of the most promising routes for the valorization of GLY.Doping has emerged as a powerful strategy to tailor the electrocatalytic performance of silver n...The efficient electrocatalytic oxidation of glycerol(GLY)is one of the most promising routes for the valorization of GLY.Doping has emerged as a powerful strategy to tailor the electrocatalytic performance of silver nanoclusters(Ag NCs),yet the effects of doping mode(surface vs.core)and the interface environment(e.g.,electrolyte concentration)on the electrocatalytic performance for Ag NCs toward GLY oxidation remain understood.In this work,surface-doped Ag_(4)M_(2)(SR)_(8) and core-doped Ag_(24)M(SR)_(18)(M=Ni,Pd,Pt;SR=SPhMe_(2))NCs were synthesized for electrocatalytic GLY oxidation.The results revealed a strong dependence of selectivity on doping mode and electrolyte concentration:under low KOH concentration,Pd-and Pt-doped Ag_(4)M_(2) NCs exhibited 100%selectivity toward oxalic acid(OA),whereas Pd-and Pt-doped Ag_(24)M NCs delivered>95%selectivity for formic acid(FA).In contrast,under high KOH concentration,Pd-and Pt-doped Ag_(4)M_(2) NCs gave rise to>80%FA,while Pd-and Pt-doped Ag_(24)M NCs produced>45%FA.Mechanism studies indicated that Ni doping predominantly enhanced catalytic activity via lowering the activation barrier of the initial reaction step(GLY→glyceraldehyde),whereas Pd and Pt doping modulated selectivity through reducing the energy barrier of the selective branch step(glyceric acid→OA,OA→FA).High KOH concentration promoted the oxidation by increasing the electrochemical active surface area and facilitating electron transfer of Ag NCs.This study provides clear guidance for designing high-performance Ag-based electrocatalysts for biomass valorization.展开更多
The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,an...The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,and the Hen’s Egg Test-Chorioallantoic Membrane were also processed to assess the mildness.As a result,bisabolol,pongamia pinnata seed extract,pterocarpus marsupium bark extract and other materials were screened as the effective and gentle sunscreen synergistic ingredients.展开更多
The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,rem...The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,remove toxins,clear heat,and alleviate wind-heat syndromes.It also has hepatoprotective,anti-inflammatory,antiviral,antibacterial,anticancer,antioxidant,antiaging,and anti-obesity effects,as well as potential therapeutic effects on Alzheimer’s disease and diabetic nephropathy.It is used to treat scrofula,mastitis,wind-heat common cold,and other ailments.The review summarizes the chemical constituents and pharmacological effects of F.suspensa,aiming to provide a scientific foundation for its future development,research,and clinical utilization.展开更多
The Zeeman effect,a fundamental quantum phenomenon,demonstrates the interaction between magnetic fields and atomic systems.While precise spectroscopic measurements of this effect have advanced significantly,there rema...The Zeeman effect,a fundamental quantum phenomenon,demonstrates the interaction between magnetic fields and atomic systems.While precise spectroscopic measurements of this effect have advanced significantly,there remains a lack of simple,visually accessible demonstration for educational purposes.Here,we present a low-cost experiment that allows for direct visual observation of the Zeeman effect.Our setup involves a flame containing sodium(from table salt)placed in front of a sodium vapor lamp.When a magnetic field is applied to the flame,the shadow cast by the flame noticeably lightens,providing a clear,naked-eye demonstration of the Zeeman effect.Furthermore,we conduct two quantitative experiments using this setup,examining the effects of varying magnetic field strength and sodium concentration.This innovative approach not only enriches the experimental demonstration for teaching atomic physics at undergraduate and high school levels but also provides an open platform for students to explore the Zeeman effect through hands-on experience.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.61925110,62004184 and 62234007the Key-Area Research and Development Program of Guangdong Province under Grant No.2020B010174002.
文摘The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have difficulty reflecting practical con-ditions.This work demonstrated a multi-fingerβ-Ga_(2)O_(3) MOSFET with a maximum drain current of 0.5 A.Electrical characteris-tics were measured,and the heat dissipation of the device was investigated through infrared images.The relationship between device temperature and time/bias is analyzed.
基金Project supported by the National Defense Foundation of China (Grant No 51327010101)the National Natural Science Foundation of China (Grant No 60606022)
文摘A new self-heating effect model for 4H-SiC MESFETs is proposed based on a combination of an analytical and a computer aided design （CAD） oriented drain current model. The circuit oriented expressions of 4H-SiC low-field electron mobility and incomplete ionization rate, which are related to temperature, are presented in this model, which are used to estimate the self-heating effect of 4H-SiC MESFETs. The verification of the present model is made, and the good agreement between simulated results and measured data of DC I - V curves with the self-heating effect is obtained.
文摘Dynamic self-heating effect(SHE)of silicon-on-insulator(SOI)MOSFET is comprehensively evaluated by ultrafast pulsed I-V measurement in this work.It is found for the first time that the SHE complete heating response and cooling response of SOI MOSFETs are conjugated,with two-stage curves shown.We establish the effective thermal transient response model with stage superposition corresponding to the heating process.The systematic study of SHE dependence on workload shows that frequency and duty cycle have more significant effect on SHE in first-stage heating process than in the second stage.In the first-stage heating process,the peak lattice temperature and current oscillation amplitude decrease by more than 25 K and 4%with frequency increasing to 10 MHz,and when duty cycle is reduced to 25%,the peak lattice temperature drops to 306 K and current oscillation amplitude decreases to 0.77%.Finally,the investigation of two-stage(heating and cooling)process provides a guideline for the unified optimization of dynamic SHE in terms of workload.As the operating frequency is raised to GHz,the peak temperature depends on duty cycle,and self-heating oscillation is completely suppressed.
基金supported by National Natural Science Foundation of China (No.10905044)
文摘For exploiting advantages of electron beam air plasma in some unusual applications, a Monte Carlo （MC） model coupled with heat transfer model is established to simulate the characteristics of electron beam air plasma by considering the self-heating effect. Based on the model, the electron beam induced temperature field and the related plasma properties are investigated. The results indicate that a nonuniform temperature field is formed in the electron beam plasma region and the average temperature is of the order of 600 K. Moreover, much larger volume pear-shaped electron beam plasma is produced in hot state rather than in cold state. The beam ranges can, with beam energies of 75 keV and 80 keV, exceed 1.0 m and 1.2 m in air at pressure of 100 torr, respectively. Finally, a well verified formula is obtained for calculating the range of high energy electron beam in atmosphere.
基金Project supported by the National Natural Science Foundation of China (Grant No 60606022)the State Key Development Program for Basic Research of China (Grant No 51327010101)Xi’an Applied Materials Innovation Fund,China (Grant No XA-AM-200702)
文摘A thermal model of 4H-SiC MESFET is developed based on the temperature dependences of material parameters and three-region I - V model. The static current characteristics of 4H-SiC MESFET have been obtained with the consideration of the self-heating effect on related parameters including electron mobility, saturation velocity and thermal conductivity. High voltage performances are analysed using equivalent thermal conductivity model. Using the physicalbased simulations, we studied the dependence of self-heating temperature on the thickness and doping of substrate. The obtained results can be used for optimization of the thermal design of the SiC-based high-power field effect transistors.
基金Supported by the Special Funds for Major State Basic Research Projects(NO.G20000365)and the National Natural Science Foundation of China(No.90101012)
文摘An inherent self-heating effect of the silicon-on-insulator (SOI) devices limits their application at high current levels. In this paper a novel solution to reduce the self-heating effect is proposed, based on N+ and O+ co-implantation into silicon wafer to form a new buried layer structure. This new structure was simulated using Medici program, and the temperature distribution and output characteristics were compared with those of the conventional SOI counterparts. As expected, a reduction of self-heating effect in the novel SOI device was observed.
基金Supported by the Special Funds for Major State Basic Research Projects (No.G2000036506)the National Natural Science Foundation of China (No. 60476006)
文摘Compared with bulk-silicon technology, silicon-on-insulator (SOI) technology possesses many advan-tages but it is inevitable that the buried silicon dioxide layer also thermally insulates the metal – oxide – silicon field-effect transistors (MOSFETs) from the bulk due to the low thermal conductivity. One of the alternative insulator to replace the buried oxide layer is aluminum nitride (AlN), which has a thermal conductivity that is about 200 times higher than that of SiO2 (320 W·m ? 1·K? 1 versus 1.4 W·m? 1·K? 1). To investigate the self-heating effects of small-size MOSFETs fabricated on silicon-on-aluminum nitride (SOAN) substrate, a two-dimensional numerical analysis is performed by using a device simulator called MEDICI run on a Solaris workstation to simulate the electri-cal characteristics and temperature distribution by comparing with those of bulk and standard SOI MOSFETs. Our study suggests that AlN is a suitable alternative to silicon dioxide as a buried dielectric in SOI and expands the appli-cations of SOI to high temperature conditions.
基金supported by the National Key Technology Research and Development Program of China(No.2016YFA0202101)the National Natural Science Foundation of China(Nos.61421005,61604005)+1 种基金the National High-Tech R&D Program(863 Program)(No.2015AA016501)The simulation was carried out at National Supercomputer Center in Tianjin,with Tian He-1(A)
文摘We use an electro-thermal coupled Monte Carlo simulation framework to investigate the self-heating effect（SHE） in 14 nm bulk n Fin FETs with ambient temperature（TA） from 220 to 400 K. Based on this method, nonlocal heat generation can be achieved. Contact thermal resistances of Si/Metal and Si/Si O_2 are selected to ensure that the source and drain heat dissipation paths are the first two heat dissipation paths. The results are listed below：（i） not all input power（Q_（input） turns into heat generation in the device region and some is taken out by the thermal non-equilibrium carriers, owing to the serious non-equilibrium transport;（ii） a higher TA leads to a larger ratio of input power turning into heat generation in the device region at the same operating voltages;（iii） SHE can lead to serious degradation in the carrier transport, which will increase when TA increases;（iv） the current degradation can be 8.9% when Vds = 0.7 V, Vgs = 1 V and TA = 400 K;（v） device thermal resistance（Rth） increases with increasing of TA, which is seriously impacted by the non-equilibrium transport. Hence, the impact of TA should be carefully considered when investigating SHE in nanoscale devices.
基金Project supported by the National Natural Science Foundation of China(Nos.60976068,60936005)the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China(No.708083)the Specialized Research Fund for the Doctoral Program of Higher Education,China(No.200807010010)
文摘To reduce the self-heating effect of strained Si grown on relaxed SiGe-on-insulator（SGOI） n-type metal-oxide-semiconductor field-effect transistors（nMOSFETs）,this paper proposes a novel device called double step buried oxide（BOX） SGOI,investigates its electrical and thermal characteristics,and analyzes the effect of self-heating on its electrical parameters.During the simulation of the device,a low field mobility model for strained Si MOSFETs is established and reduced thermal conductivity resulting from phonon boundary scattering is considered.A comparative study of SGOI nMOSFETs with different BOX thicknesses under channel and different channel strains has been performed.By reducing moderately the BOX thickness under the channel,the channel temperature caused by the self-heating effect can be effectively reduced.Moreover,mobility degradation,off state current and a short-channel effect such as drain induced barrier lowering can be well suppressed.Therefore,SGOI MOSFETs with a thinner BOX under the channel can improve the overall performance and long-term reliability efficiently.
基金supported by the National Natural Science Foundation of China(No.60606006)the Key Science&Technology Special Project of Shaanxi Province,China(No.2011KTCQ01-19)the National Defense Pre-Research Foundation of China(No.9140A23060111)
文摘Considering the self-heating effect, an accurate expression for the global interconnection resistance per unit length in terms of interconnection wire width and spacing is presented. Based on the proposed resistance model and according to the trade-off theory, a novel optimization analytical model of delay, power dissipation and bandwidth is derived. The proposed optimal model is verified and compared based on 90 nm, 65 nm and 40 nm CMOS technologies. It can be found that more optimum results can be easily obtained by the proposed model. This optimization model is more accurate and realistic than the conventional optimization models, and can be integrated into the global interconnection design ofnano-scale integrated circuits.
文摘An analytical DC model accounting for the self-heating effect of polycrystalline silicon thin-film transistors（poly-Si TFTs） is presented.In deriving the model for the self-heating effect, the temperature dependence of the effective mobility is studied in detail.Based on the mobility model and a first order approximation, a closed-form analytical drain current model considering the self-heating effect is derived.Compared with the available experimental data, the proposed model, which includes the self-heating and kink effects, provides an accurate description of the output characteristics over the linear, the saturation, and the kink regimes.
文摘Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.
基金National Natural Science Foundation of China(11875039)Shanxi Scholarship Council of China(2023-033)+2 种基金Fundamental Research Program of Shanxi Province(202303021221071)China Baowu Low Carbon Metallurgical Innovation Foundation(2022)2023 Anhui Major Industrial Innovation Plan Project。
文摘The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.
基金supported by the National Natural Science Foundation of China“Research on the Multi-scale Regional Industrial Spatial Evolution Mechanism,Resource and Environmental Effects,and Green Transformation in the Yellow River Basin”[Grant No.42371194]Taishan Scholar Foundation of Shandong Province[Grant Nos.tsqn202408148 and tstp20240821].
文摘Agglomeration supports the high-quality development of the manufacturing industry,and its associated resource and environmental effects play a crucial role in driving green economic development.Based on data from prefecture-level cities in China from 2005 to 2019,this study employs the inverse distance weighting method,the bivariate local indicator of spatial association model,the spatial Durbin model,and other techniques to explore the relationship between manufacturing agglomeration and PM_(2.5)concentrations,and to assess the impact of its manufacturing agglomeration.Four correlation patterns are observed:high-high,low-low,high-low,and low-high.Among these,high-high and low-low patterns dominate in terms of number of cities.These correlation patterns demonstrate strong temporal stability,with a clear“Matthew effect”.The effect of manufacturing agglomeration on PM_(2.5)levels is significantly negative and helps reduce concentrations regionally,indicating the need to further enhance agglomeration levels regionally.However,it can increase PM_(2.5)levels in neighboring areas due to a siphon effect,and the impact of varies across regions.Compared with levels in 2005-2013,the significance of the relationship between manufacturing agglomeration and PM_(2.5)weakened in the 2013-2019 period.Accordingly,this study proposes countermeasures and policy recommendations aimed at strengthening regional collaborative governance and inspiring differentiated agglomeration strategies to support sustainable economic development in China.
文摘Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.
基金supported by the National Natural Science Foundation of China(No.62464010)Spring City Plan-Special Program for Young Talents(K202005007)+2 种基金Yunnan Talents Support Plan for Young Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Frontier Research Team of Kunming University 2023.
文摘Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.
基金support from the Jiangsu Natural Science Foundation of China(BK20230329)the National Natural Science Foundation of China(22401147,22361132540,and 22178161)the Russian Science Foundation(23-73-30007).
文摘The efficient electrocatalytic oxidation of glycerol(GLY)is one of the most promising routes for the valorization of GLY.Doping has emerged as a powerful strategy to tailor the electrocatalytic performance of silver nanoclusters(Ag NCs),yet the effects of doping mode(surface vs.core)and the interface environment(e.g.,electrolyte concentration)on the electrocatalytic performance for Ag NCs toward GLY oxidation remain understood.In this work,surface-doped Ag_(4)M_(2)(SR)_(8) and core-doped Ag_(24)M(SR)_(18)(M=Ni,Pd,Pt;SR=SPhMe_(2))NCs were synthesized for electrocatalytic GLY oxidation.The results revealed a strong dependence of selectivity on doping mode and electrolyte concentration:under low KOH concentration,Pd-and Pt-doped Ag_(4)M_(2) NCs exhibited 100%selectivity toward oxalic acid(OA),whereas Pd-and Pt-doped Ag_(24)M NCs delivered>95%selectivity for formic acid(FA).In contrast,under high KOH concentration,Pd-and Pt-doped Ag_(4)M_(2) NCs gave rise to>80%FA,while Pd-and Pt-doped Ag_(24)M NCs produced>45%FA.Mechanism studies indicated that Ni doping predominantly enhanced catalytic activity via lowering the activation barrier of the initial reaction step(GLY→glyceraldehyde),whereas Pd and Pt doping modulated selectivity through reducing the energy barrier of the selective branch step(glyceric acid→OA,OA→FA).High KOH concentration promoted the oxidation by increasing the electrochemical active surface area and facilitating electron transfer of Ag NCs.This study provides clear guidance for designing high-performance Ag-based electrocatalysts for biomass valorization.
文摘The UV-2600 ultraviolet(UV)spectrophotometer and the UV sunscreen index analyzer SolarLight Model 601 were used to test the UV absorption capacity and the UV damage alleviating effect of commonly used raw materials,and the Hen’s Egg Test-Chorioallantoic Membrane were also processed to assess the mildness.As a result,bisabolol,pongamia pinnata seed extract,pterocarpus marsupium bark extract and other materials were screened as the effective and gentle sunscreen synergistic ingredients.
文摘The dried fruit of Forsythia suspensa(Oleaceae),also known as Forsythia,is a traditional Chinese medicinal herb known for its heat-clearing and detoxifying properties.It is used to disperse nodules,reduce swelling,remove toxins,clear heat,and alleviate wind-heat syndromes.It also has hepatoprotective,anti-inflammatory,antiviral,antibacterial,anticancer,antioxidant,antiaging,and anti-obesity effects,as well as potential therapeutic effects on Alzheimer’s disease and diabetic nephropathy.It is used to treat scrofula,mastitis,wind-heat common cold,and other ailments.The review summarizes the chemical constituents and pharmacological effects of F.suspensa,aiming to provide a scientific foundation for its future development,research,and clinical utilization.
基金the National Natural Science Foundation of China for support under grant No.12305037the Fundamental Research Funds for the Central Universities under grant No.2023NTST017。
文摘The Zeeman effect,a fundamental quantum phenomenon,demonstrates the interaction between magnetic fields and atomic systems.While precise spectroscopic measurements of this effect have advanced significantly,there remains a lack of simple,visually accessible demonstration for educational purposes.Here,we present a low-cost experiment that allows for direct visual observation of the Zeeman effect.Our setup involves a flame containing sodium(from table salt)placed in front of a sodium vapor lamp.When a magnetic field is applied to the flame,the shadow cast by the flame noticeably lightens,providing a clear,naked-eye demonstration of the Zeeman effect.Furthermore,we conduct two quantitative experiments using this setup,examining the effects of varying magnetic field strength and sodium concentration.This innovative approach not only enriches the experimental demonstration for teaching atomic physics at undergraduate and high school levels but also provides an open platform for students to explore the Zeeman effect through hands-on experience.
