Submicron scale temperature sensors are crucial for a range of applications,particularly in micro and na-noscale environments.One promising solution involves the use of active whispering gallery mode(WGM)microresonato...Submicron scale temperature sensors are crucial for a range of applications,particularly in micro and na-noscale environments.One promising solution involves the use of active whispering gallery mode(WGM)microresonators.These resonators can be remotely excited and read out using free-space structures,simplifying the process of sensing.In this study,we present a submicron-scale temperature sensor with a remarkable sensitivity up to 185 pm/℃based on a trian-gular MAPbI3 nanoplatelet(NPL)laser.Notably,as temperature changes,the peak wavelength of the laser line shifts lin-early.This unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL laser.The optical modes are confined within the perovskite NPL,which measures just 85 nm in height,due to total internal reflec-tion.Our NPL laser boasts several key features,including a high Q of~2610 and a low laser threshold of about 19.8μJ·cm^(−2).The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature sensors.This advancement paves the way for significant prog-ress in the development of ultrasmall temperature sensors,opening new possibilities across various fields.展开更多
With a reduction in transistor dimensions to the nanoscale regime of 45 nm or less, quantum mechanical effects begin to reveal themselves and have an impact on key device performance parameters. As a result, in order ...With a reduction in transistor dimensions to the nanoscale regime of 45 nm or less, quantum mechanical effects begin to reveal themselves and have an impact on key device performance parameters. As a result, in order to develop simulation tools that can be used for the design of nanoscale transistors in the future, new theories and modelling methodologies must be developed that properly and effectively capture the physics of quantum transport. An artificial neural network(ANN) is used in this paper to examine nanoscale CMOS circuits and predict the performance parameters of CMOS-based digital inverters for a temperature range of 300 K to 400 K. The training algorithm included three hidden layers with sizes of 20, 10, and 8, as well as a function fitting ANN with Bayesian Backpropagation Regularization. Further, simulation through HSPICE using Predictive Technology Model(PTM) nominal parameters has been done to compare with ANN(trained using an analytical model) results. The obtained results lie within the acceptable range of 1%-10%. Moreover, it has also been demonstrated that the ANN simulation provides a speed improvement of around 85 % over the HSPICE simulation, and that it can be easily integrated into software tools for designing and simulating complicated CMOS logic circuits.展开更多
Voltage scaling has been extensively used in industry for decades to reduce power consumption.In recent years,exploring digital circuit operation in moderate inversion has created an interest among researchers due to ...Voltage scaling has been extensively used in industry for decades to reduce power consumption.In recent years,exploring digital circuit operation in moderate inversion has created an interest among researchers due to its immense capability to provide a perfect tradeoff between high performance and low energy operation.But circuits operating in moderate inversion are susceptible to process variations and variability.To compute variability,statistical parameters such as the probability density function(PDF)and cumulative distribution function(CDF)are required.This paper presents an analytical model framework for delay calculations utilizing log skew normal distribution for ultradeep submicron technology nodes up to 22 nm.The CDF of the proposed model is utilized to calculate minimum and maximum delays with 3σ-accuracy providing better accuracy than the conventional methods.The obtained results are also compared with Monte Carlo simulations with errors lying within the acceptable range of 2%-4%.展开更多
Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy wer...Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy were experimentally investigated, and the influence of the extrusion temperature on its microstructure and properties was made clear. Also, the strengthening mechanism of the alloy was discussed. It was revealed that the microstructure of the alloy is very fine, with an average grain size being about 100~120 nm, and thus possesses significant fine grain strengthening effect, leading to very high mechanical strength of 800~1 000 MPa. Meanwhile, the alloy also possesses quite good electrical conductivity and moderate tensile elongation, with the former in the range of 55%~70%(IACS) and the latter about 5% respectively.展开更多
The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) an...The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The results showed that Mo2C formed at 800degreesC or below. Both WC and Mo2C disappeared at 1200degreesC, and TiN disappeared at 1250degreesC. In addition, the variations of lattice constants of the titanium carbonitride and nickel binder phase with sintering temperature were experimentally obtained, and the reason was analyzed.展开更多
In this study, WC-Co powder with WC submicron grain size of 0. 7 - 0. 9μm was used as feedstock powder to deposit wear resistant coating by home-made T J-9000 HVOF system. The deposition efficiency of the feedstock p...In this study, WC-Co powder with WC submicron grain size of 0. 7 - 0. 9μm was used as feedstock powder to deposit wear resistant coating by home-made T J-9000 HVOF system. The deposition efficiency of the feedstock powder was examined. Influences of the High Velocity Oxy-Fuel (HVOF) spraying parameters on the microstructures, phase compositions, microhardness, and wear resistance of sprayed coatings were investigated. The deposition efficiency of the feedstock powder was very high, and reached to 58%. The sprayed coatings were very dense, and their porosities were lower than 1% and could be lowered than 0. 42% with optimal spraying parameters. According to the X-ray Diffraction ( XRD ) analysis, the phase compositions of the sprayed coatings consisted of WC, Co, W2 C, and Co6 W6 C. W appeared at high flame power. The average microhardness of the coating was 1 100 HVo 1 and had reversely linear relationship with the porosity of coatings. The weight loss of the counter wear ring GCrl5 was 20 times than that of the sprayed WC-Co coating. At the load of 15 kg and rotational speed of 200 r/min of GCr15 counter wear ring, the friction coefficient was 0. 68 in the dry wear conditions. It was concluded that the sprayed submicron structural WC-12Co coating had good wear resistance.展开更多
In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetiz...In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetizing effect and ferromagnetic resonance data. By theoretical simulation, the magnetization, gyromagnetic ratio and g value of the sample are determined. The theoretical curves of the dependence of the resonance field on the field orientation φ H fit well with the experimental data. When the steady magnetic field is applied near the film normal, a series of additional regular peaks (up to eight ) appeared in the FMR spectrum on the low field side of the main FMR peak. The resonance field of these side peaks decreases linearly with the peak number. The possible physical mechanism of these multiple peaks was discussed.展开更多
Base metal nickel is often used as the inner electrode in multilayer chip positive temperature coefficient resistance (PTCR). The fine grain of ceramic powders and base metal nickel are necessary. This paper uses re...Base metal nickel is often used as the inner electrode in multilayer chip positive temperature coefficient resistance (PTCR). The fine grain of ceramic powders and base metal nickel are necessary. This paper uses reducing hydrazine to gain submicron nickel powder whose diameter was 200-300 nm through adjusting the consumption of nucleating agent PVP properly. The submicron nickel powder could disperse well and was fit for co--fired of multilayer chip PTCR. It analyes the submicron nickel powder through x-ray Diffraction (XRD) and calculates the diameter of nickel by PDF cards. Using XRD analyses it obtains several conclusions: If the molar ratio of hydrazine hydrate and nickel sulfate is kept to be a constant, when enlarging the molar ratio of NaOH/Ni^2+, the diameter of nickel powder would become smaller. When the temperature in the experiment raises to 70-80 ℃, nickel powder becomes smaller too. And if the molar ratio of NaOH/Ni2+ is 4, when molar ratio of (C2H5O)2/Ni^2+ increases, the diameter of nickel would reduce. Results from viewing the powders by optical microscope should be the fact that the electrode made by submicron nickel powder has a better formation and compactness. Furthermore, the sheet resistance testing shows that the electrode made by submicron nickel is smaller than that made by micron nickel.展开更多
Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects f...Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects for commercial application,such as uncontrollable ordered layered structure,which leads to higher energy barrier for Li+diffusion.In addition,suffering from structural mutability,the bulk nickelrich cathode materials likely trigger overall volumetric variation and intergranular cracks,thus obstructing the lithium ion diffusion path and shortening the service life of the whole device.Herein,we report wellordered layered Li Ni0.8Co0.1Mn0.1O2 submicron spheroidal particles via an optimized co-precipitation and investigated as LIBs cathodes for high-performance lithium storage.The as-fabricated Li Ni0.8Co0.1Mn0.1O2 delivers high initial capacity of 228 mAh g–1,remarkable energy density of 866 Wh kg–1,rapid Li ion diffusion coefficient(10–9cm2s–1)and low voltage decay.The remarkable electrochemical performance should be ascribed to the well-ordered layered structure and uniform submicron spheroidal particles,which enhance the structural stability and ameliorate strain relaxation via reducing the parcel size and shortening Li-ion diffusion distance.This work anticipatorily provides an inspiration to better design particle morphology for structural stability and rate capability in electrochemistry energy storage devices.展开更多
An 2024Al matrix composite reinforced with 36%(volume fraction)β-Si_(3)N_(4) particles was fabricated by pressure infiltration method,and its microstructure and the effect of annealing treatment on thermo-conductivit...An 2024Al matrix composite reinforced with 36%(volume fraction)β-Si_(3)N_(4) particles was fabricated by pressure infiltration method,and its microstructure and the effect of annealing treatment on thermo-conductivity were discussed.Si_(3)N_(4) particles distribute uniformly without any particle clustering and no apparent particle porosity or significant casting defects are observed in the composites.The combination of particles and matrix is well.The raw Si_(3)N_(4) particles are regular cylindrical polyhedron with flat surface and change to serrated surface in composite due to reactions during fabrication.Thermal conductivity of as-cast Si_(3)N_(4)p/2024 composite is 90.125 W/(m·K)at room temperature,and increases to 94.997 W/(m·K)after annealing treatment. The calculated results of thermal conductivity of the Si_(3)N_(4p)/Al composite by Maxwell model,H-S model and PG model are lower than experimental results while that by ROM model is higher.展开更多
To improve the removal efficiency of such submicron inclusions,we designed an argon blowing method for an RH facility based on mathematical simulations.The effect of the argon blowing on the liquid steel flow and the ...To improve the removal efficiency of such submicron inclusions,we designed an argon blowing method for an RH facility based on mathematical simulations.The effect of the argon blowing on the liquid steel flow and the movement of submicron inclusions was studied using the k-ε flow model coupled with the DPM model for inclusion movement based on fluid computational dynamics in FLUENT.It was found that a more uniform argon flow can be achieved in the up-leg snorkel with a new nozzle position and inner diameter,which resulted in a favorable up-lifting and mixing movement.The new design also increased the circulation rate of molten steel in the RH chamber.The increased turbulent kinetic energy and turbulent dispersing rate enhanced the collision probability of submicron inclusions,which results in an improved removal for 0.5-1 μm inclusions.The proposed RH facility could increase the removal rate of submicron inclusions from the original 57.1% to 66.4%,which improves the magnetic properties of non-oriented silicon steel.展开更多
A new cement free iron trough castable was prepared with dense corundum and silicon carbide as the main raw materials and submicron SiO_(2) powder(d_(50)=0.242μm,SiO_(2)=99.9 mass%)as the binder.The effect of the sub...A new cement free iron trough castable was prepared with dense corundum and silicon carbide as the main raw materials and submicron SiO_(2) powder(d_(50)=0.242μm,SiO_(2)=99.9 mass%)as the binder.The effect of the submicron SiO_(2) powder addition(3%,4%,5%,6%,7%,8%,and 9%,by mass,respectively)on the properties of the prepared castables was studied.The working mechanism of submicron SiO_(2) powder was analyzed from the perspective of the particle size distribution and infrared absorption spectrum.The results show that:(1)cement free iron trough castables can be prepared using submicron SiO_(2) powder alone as the binder;(2)compared with traditional castables,the cement free castables have made a breakthrough in the water addition and hot modulus of rupture.The optimal submicron SiO_(2) powder addition is 4%-6%.展开更多
Nickel particles with submicron size are prepared by using the solvothermal method. These spheres are then coated with a layer of MnO2 using the soft chemical method. The microstructure is characterized by x-ray diffr...Nickel particles with submicron size are prepared by using the solvothermal method. These spheres are then coated with a layer of MnO2 using the soft chemical method. The microstructure is characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Energy x-ray dispersive spectrometry and high- resolution images show that the granular composites have a classical core/shell structure with an MnO2 superficial layer, no more than 10 nm in thickness. The hysteresis measurements indicate that these submicron-size Ni composite powders have small remanence and moderate coercivity. The electromagnetic properties of the powders measured by a vector network analyzer in a frequency range of 2-18 GHz are also reported in detail.展开更多
This paper reviews various fabrication methods of ultrafine grained materials and their limitations briefly, and examines the possibility to produce ultrafine grained titanium alloy by compressive deformation prelimin...This paper reviews various fabrication methods of ultrafine grained materials and their limitations briefly, and examines the possibility to produce ultrafine grained titanium alloy by compressive deformation preliminarily. It has been shown that submicrongrained TC11 alloy can be obtained by compressive deformation below 725°C. During microstructure refinement, dynamic recrystallization occurs only in α phases, and β phases undergo a process of precipitation and growth. Compared with the situation of static annealing, deformation can not only enhance the precipitation and growth of β phases but also change the morphology of βprecipitates.展开更多
2D and 3D submicron periodic structures are first fabricated by red-induced photopolymerization using a common 635 nm semiconductor laser and specially developed red-sensitive polymer material. The principle of this n...2D and 3D submicron periodic structures are first fabricated by red-induced photopolymerization using a common 635 nm semiconductor laser and specially developed red-sensitive polymer material. The principle of this new photo- polymer material fabrication is explained and the absorption spectra of the material are measured. This fabrication technique allows a deeper penetration into volume and larger interference irradiation area which is more than 1 cm2. The optical design, theoretical calculations and experimental results including diffraction patterns verifying the forma- tion of periodic structures are presented. Compared with other fabrication technologies using high-power lasers, this approach has greatly reduced the demand for laser apparatus. Therefore, it is much more accessible to most. laboratories and potentially usable in holographic fabrication of photonic crystals and devices in micro electro-mechanical systems (MEMS).展开更多
The synthesis and dielectric properties of calcium titanate (CaTiO3) submicron powder synthesized by mechanical ball-milling method have been investigated in this paper. With the ball-milling time increased, the siz...The synthesis and dielectric properties of calcium titanate (CaTiO3) submicron powder synthesized by mechanical ball-milling method have been investigated in this paper. With the ball-milling time increased, the size of CaTiO3 particles decreased from micron to submicron, and a great deal of nanoparticles (50-100 nm) occurred. The CaTiO3 ceramics made from submicron powders achieved compact structure at the sintering temperature of 1 250℃, and had good dielectric properties: εr=171, Q×f= 4 361 GHz, τf =+782 ppm/+C, IR=6.5×10^12Ω, which was a similar result compared with the CaTiO3 ceramics made from nanoparticles by sol-gel method.展开更多
Hot carrier injection (HCI) at high temperatures and different values of gate bias Vg has been performed in order to study the actions of negative bias temperature instability (NBTI) and hot carriers. Hot-carrier-...Hot carrier injection (HCI) at high temperatures and different values of gate bias Vg has been performed in order to study the actions of negative bias temperature instability (NBTI) and hot carriers. Hot-carrier-stress-induced damage at Vg = Vd, where Vd is the voltage of the transistor drain, increases as temperature rises, contrary to conventional hot carrier behaviour, which is identified as being related to the NBTI. A comparison between the actions of NBTI and hot carriers at low and high gate voltages shows that the damage behaviours are quite different: the low gate voltage stress results in an increase in transconductance, while the NBTI-dominated high gate voltage and high temperature stress causes a decrease in transconductance. It is concluded that this can be a major source of hot carrier damage at elevated temperatures and high gate voltage stressing of p-channel metal-oxide-semiconductor field-effect transistors (PMOSFETs). We demonstrate a novel mode of NBTI-enhanced hot carrier degradation in PMOSFETs. A novel method to decouple the actions of NBTI from that of hot carriers is also presented.展开更多
A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experi...A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.展开更多
Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integra...Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integrated circuits.2.Deep submicron LDD CMOS devices and integrated circuits.3.C band and Ku band microwave GaAs MESFET and III-V compound hetrojunction HEM T and HBT devices and integrated circuits.展开更多
To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chrom...To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chromatography coupled with tandem mass spectrometry detection(UPLC-MS/MS)through a new validated method.The pharmacokinetic parameters of the nitrendipine submicron emulsion and nitrendipine solution were as follows:AUC_(0-t) 900.76±186.59 versus 687.08±66.24 ng h/ml,C_(max) 854.54±159.48 versus 610.59±235.99 ng/ml,t_(1/2)2.37±1.99 versus 2.80±2.69 h.The relative bioavailability of nitrendipine submicron emulsion to nitrendipine solution was 131.4±11.3%.The developed methods could meet the requirements of bioanalysis.Compared to the solution injection,intravenous submicron emulsion presents higher systematic exposure which can help to improve the therapeutic efficacy.展开更多
文摘Submicron scale temperature sensors are crucial for a range of applications,particularly in micro and na-noscale environments.One promising solution involves the use of active whispering gallery mode(WGM)microresonators.These resonators can be remotely excited and read out using free-space structures,simplifying the process of sensing.In this study,we present a submicron-scale temperature sensor with a remarkable sensitivity up to 185 pm/℃based on a trian-gular MAPbI3 nanoplatelet(NPL)laser.Notably,as temperature changes,the peak wavelength of the laser line shifts lin-early.This unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL laser.The optical modes are confined within the perovskite NPL,which measures just 85 nm in height,due to total internal reflec-tion.Our NPL laser boasts several key features,including a high Q of~2610 and a low laser threshold of about 19.8μJ·cm^(−2).The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature sensors.This advancement paves the way for significant prog-ress in the development of ultrasmall temperature sensors,opening new possibilities across various fields.
文摘With a reduction in transistor dimensions to the nanoscale regime of 45 nm or less, quantum mechanical effects begin to reveal themselves and have an impact on key device performance parameters. As a result, in order to develop simulation tools that can be used for the design of nanoscale transistors in the future, new theories and modelling methodologies must be developed that properly and effectively capture the physics of quantum transport. An artificial neural network(ANN) is used in this paper to examine nanoscale CMOS circuits and predict the performance parameters of CMOS-based digital inverters for a temperature range of 300 K to 400 K. The training algorithm included three hidden layers with sizes of 20, 10, and 8, as well as a function fitting ANN with Bayesian Backpropagation Regularization. Further, simulation through HSPICE using Predictive Technology Model(PTM) nominal parameters has been done to compare with ANN(trained using an analytical model) results. The obtained results lie within the acceptable range of 1%-10%. Moreover, it has also been demonstrated that the ANN simulation provides a speed improvement of around 85 % over the HSPICE simulation, and that it can be easily integrated into software tools for designing and simulating complicated CMOS logic circuits.
文摘Voltage scaling has been extensively used in industry for decades to reduce power consumption.In recent years,exploring digital circuit operation in moderate inversion has created an interest among researchers due to its immense capability to provide a perfect tradeoff between high performance and low energy operation.But circuits operating in moderate inversion are susceptible to process variations and variability.To compute variability,statistical parameters such as the probability density function(PDF)and cumulative distribution function(CDF)are required.This paper presents an analytical model framework for delay calculations utilizing log skew normal distribution for ultradeep submicron technology nodes up to 22 nm.The CDF of the proposed model is utilized to calculate minimum and maximum delays with 3σ-accuracy providing better accuracy than the conventional methods.The obtained results are also compared with Monte Carlo simulations with errors lying within the acceptable range of 2%-4%.
文摘Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy were experimentally investigated, and the influence of the extrusion temperature on its microstructure and properties was made clear. Also, the strengthening mechanism of the alloy was discussed. It was revealed that the microstructure of the alloy is very fine, with an average grain size being about 100~120 nm, and thus possesses significant fine grain strengthening effect, leading to very high mechanical strength of 800~1 000 MPa. Meanwhile, the alloy also possesses quite good electrical conductivity and moderate tensile elongation, with the former in the range of 55%~70%(IACS) and the latter about 5% respectively.
基金This work wasfinancially supported by the National Natural Science Foundation Of China (50074017), the NationalDoctorate Progr
文摘The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The results showed that Mo2C formed at 800degreesC or below. Both WC and Mo2C disappeared at 1200degreesC, and TiN disappeared at 1250degreesC. In addition, the variations of lattice constants of the titanium carbonitride and nickel binder phase with sintering temperature were experimentally obtained, and the reason was analyzed.
文摘In this study, WC-Co powder with WC submicron grain size of 0. 7 - 0. 9μm was used as feedstock powder to deposit wear resistant coating by home-made T J-9000 HVOF system. The deposition efficiency of the feedstock powder was examined. Influences of the High Velocity Oxy-Fuel (HVOF) spraying parameters on the microstructures, phase compositions, microhardness, and wear resistance of sprayed coatings were investigated. The deposition efficiency of the feedstock powder was very high, and reached to 58%. The sprayed coatings were very dense, and their porosities were lower than 1% and could be lowered than 0. 42% with optimal spraying parameters. According to the X-ray Diffraction ( XRD ) analysis, the phase compositions of the sprayed coatings consisted of WC, Co, W2 C, and Co6 W6 C. W appeared at high flame power. The average microhardness of the coating was 1 100 HVo 1 and had reversely linear relationship with the porosity of coatings. The weight loss of the counter wear ring GCrl5 was 20 times than that of the sprayed WC-Co coating. At the load of 15 kg and rotational speed of 200 r/min of GCr15 counter wear ring, the friction coefficient was 0. 68 in the dry wear conditions. It was concluded that the sprayed submicron structural WC-12Co coating had good wear resistance.
文摘In this paper, we report a ferromagnetic resonance study on the permalloy film of submicron sized rectangular arrays prepared by electron beam lithography and the theoretical simulation to the non uniform demagnetizing effect and ferromagnetic resonance data. By theoretical simulation, the magnetization, gyromagnetic ratio and g value of the sample are determined. The theoretical curves of the dependence of the resonance field on the field orientation φ H fit well with the experimental data. When the steady magnetic field is applied near the film normal, a series of additional regular peaks (up to eight ) appeared in the FMR spectrum on the low field side of the main FMR peak. The resonance field of these side peaks decreases linearly with the peak number. The possible physical mechanism of these multiple peaks was discussed.
基金Project supported by the "863" (Grant No. SQ2008AA03Z4471960)the National Natural Science Foundation of China(Grant No. 60676050)
文摘Base metal nickel is often used as the inner electrode in multilayer chip positive temperature coefficient resistance (PTCR). The fine grain of ceramic powders and base metal nickel are necessary. This paper uses reducing hydrazine to gain submicron nickel powder whose diameter was 200-300 nm through adjusting the consumption of nucleating agent PVP properly. The submicron nickel powder could disperse well and was fit for co--fired of multilayer chip PTCR. It analyes the submicron nickel powder through x-ray Diffraction (XRD) and calculates the diameter of nickel by PDF cards. Using XRD analyses it obtains several conclusions: If the molar ratio of hydrazine hydrate and nickel sulfate is kept to be a constant, when enlarging the molar ratio of NaOH/Ni^2+, the diameter of nickel powder would become smaller. When the temperature in the experiment raises to 70-80 ℃, nickel powder becomes smaller too. And if the molar ratio of NaOH/Ni2+ is 4, when molar ratio of (C2H5O)2/Ni^2+ increases, the diameter of nickel would reduce. Results from viewing the powders by optical microscope should be the fact that the electrode made by submicron nickel powder has a better formation and compactness. Furthermore, the sheet resistance testing shows that the electrode made by submicron nickel is smaller than that made by micron nickel.
基金supported by the National Natural Science Foundation of China (21573083)1000 Young Talent (to Deli Wang)the Innovation Research Funds of HuaZhong University of Science and Technology (2017KFYXJJ164)。
文摘Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost.However,nickel-rich layered oxides also have exposed several defects for commercial application,such as uncontrollable ordered layered structure,which leads to higher energy barrier for Li+diffusion.In addition,suffering from structural mutability,the bulk nickelrich cathode materials likely trigger overall volumetric variation and intergranular cracks,thus obstructing the lithium ion diffusion path and shortening the service life of the whole device.Herein,we report wellordered layered Li Ni0.8Co0.1Mn0.1O2 submicron spheroidal particles via an optimized co-precipitation and investigated as LIBs cathodes for high-performance lithium storage.The as-fabricated Li Ni0.8Co0.1Mn0.1O2 delivers high initial capacity of 228 mAh g–1,remarkable energy density of 866 Wh kg–1,rapid Li ion diffusion coefficient(10–9cm2s–1)and low voltage decay.The remarkable electrochemical performance should be ascribed to the well-ordered layered structure and uniform submicron spheroidal particles,which enhance the structural stability and ameliorate strain relaxation via reducing the parcel size and shortening Li-ion diffusion distance.This work anticipatorily provides an inspiration to better design particle morphology for structural stability and rate capability in electrochemistry energy storage devices.
基金Project(2003AA305110)supported by the Hi-tech Research and Development Program of China。
文摘An 2024Al matrix composite reinforced with 36%(volume fraction)β-Si_(3)N_(4) particles was fabricated by pressure infiltration method,and its microstructure and the effect of annealing treatment on thermo-conductivity were discussed.Si_(3)N_(4) particles distribute uniformly without any particle clustering and no apparent particle porosity or significant casting defects are observed in the composites.The combination of particles and matrix is well.The raw Si_(3)N_(4) particles are regular cylindrical polyhedron with flat surface and change to serrated surface in composite due to reactions during fabrication.Thermal conductivity of as-cast Si_(3)N_(4)p/2024 composite is 90.125 W/(m·K)at room temperature,and increases to 94.997 W/(m·K)after annealing treatment. The calculated results of thermal conductivity of the Si_(3)N_(4p)/Al composite by Maxwell model,H-S model and PG model are lower than experimental results while that by ROM model is higher.
基金Funded by the National Natural Science Foundation of China(No.51804231)the Key R&D Program of Hubei Province(No.2020BAA027)。
文摘To improve the removal efficiency of such submicron inclusions,we designed an argon blowing method for an RH facility based on mathematical simulations.The effect of the argon blowing on the liquid steel flow and the movement of submicron inclusions was studied using the k-ε flow model coupled with the DPM model for inclusion movement based on fluid computational dynamics in FLUENT.It was found that a more uniform argon flow can be achieved in the up-leg snorkel with a new nozzle position and inner diameter,which resulted in a favorable up-lifting and mixing movement.The new design also increased the circulation rate of molten steel in the RH chamber.The increased turbulent kinetic energy and turbulent dispersing rate enhanced the collision probability of submicron inclusions,which results in an improved removal for 0.5-1 μm inclusions.The proposed RH facility could increase the removal rate of submicron inclusions from the original 57.1% to 66.4%,which improves the magnetic properties of non-oriented silicon steel.
基金support from the National Natural Science Foundation of China(NSFC,No.51804233)。
文摘A new cement free iron trough castable was prepared with dense corundum and silicon carbide as the main raw materials and submicron SiO_(2) powder(d_(50)=0.242μm,SiO_(2)=99.9 mass%)as the binder.The effect of the submicron SiO_(2) powder addition(3%,4%,5%,6%,7%,8%,and 9%,by mass,respectively)on the properties of the prepared castables was studied.The working mechanism of submicron SiO_(2) powder was analyzed from the perspective of the particle size distribution and infrared absorption spectrum.The results show that:(1)cement free iron trough castables can be prepared using submicron SiO_(2) powder alone as the binder;(2)compared with traditional castables,the cement free castables have made a breakthrough in the water addition and hot modulus of rupture.The optimal submicron SiO_(2) powder addition is 4%-6%.
基金Project supported by the National Natural Science Foundation of China (Grant No 50671026)
文摘Nickel particles with submicron size are prepared by using the solvothermal method. These spheres are then coated with a layer of MnO2 using the soft chemical method. The microstructure is characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Energy x-ray dispersive spectrometry and high- resolution images show that the granular composites have a classical core/shell structure with an MnO2 superficial layer, no more than 10 nm in thickness. The hysteresis measurements indicate that these submicron-size Ni composite powders have small remanence and moderate coercivity. The electromagnetic properties of the powders measured by a vector network analyzer in a frequency range of 2-18 GHz are also reported in detail.
文摘This paper reviews various fabrication methods of ultrafine grained materials and their limitations briefly, and examines the possibility to produce ultrafine grained titanium alloy by compressive deformation preliminarily. It has been shown that submicrongrained TC11 alloy can be obtained by compressive deformation below 725°C. During microstructure refinement, dynamic recrystallization occurs only in α phases, and β phases undergo a process of precipitation and growth. Compared with the situation of static annealing, deformation can not only enhance the precipitation and growth of β phases but also change the morphology of βprecipitates.
基金Projiect supported by the National Key Basic Research Special Fund of China (Grant No. 2004CB719805)the Ningbo Natural Science Foundation, China (Grant No. 2009A610011)
文摘2D and 3D submicron periodic structures are first fabricated by red-induced photopolymerization using a common 635 nm semiconductor laser and specially developed red-sensitive polymer material. The principle of this new photo- polymer material fabrication is explained and the absorption spectra of the material are measured. This fabrication technique allows a deeper penetration into volume and larger interference irradiation area which is more than 1 cm2. The optical design, theoretical calculations and experimental results including diffraction patterns verifying the forma- tion of periodic structures are presented. Compared with other fabrication technologies using high-power lasers, this approach has greatly reduced the demand for laser apparatus. Therefore, it is much more accessible to most. laboratories and potentially usable in holographic fabrication of photonic crystals and devices in micro electro-mechanical systems (MEMS).
基金Supported by Zhejiang Province Key Science and Technical Program (No.2006C11119)
文摘The synthesis and dielectric properties of calcium titanate (CaTiO3) submicron powder synthesized by mechanical ball-milling method have been investigated in this paper. With the ball-milling time increased, the size of CaTiO3 particles decreased from micron to submicron, and a great deal of nanoparticles (50-100 nm) occurred. The CaTiO3 ceramics made from submicron powders achieved compact structure at the sintering temperature of 1 250℃, and had good dielectric properties: εr=171, Q×f= 4 361 GHz, τf =+782 ppm/+C, IR=6.5×10^12Ω, which was a similar result compared with the CaTiO3 ceramics made from nanoparticles by sol-gel method.
基金Project supported by the National Natural Science Foundation of China (Grant No 60206006). the Program for New Century Excellent Talents of Ministry of Education of China (Grant No 681231366). the National Defense Pre-Research Foundation of China (Grant No 51408010305DZ0168) and the Key Project of Chinese Ministry of Education (Grant No 104172).
文摘Hot carrier injection (HCI) at high temperatures and different values of gate bias Vg has been performed in order to study the actions of negative bias temperature instability (NBTI) and hot carriers. Hot-carrier-stress-induced damage at Vg = Vd, where Vd is the voltage of the transistor drain, increases as temperature rises, contrary to conventional hot carrier behaviour, which is identified as being related to the NBTI. A comparison between the actions of NBTI and hot carriers at low and high gate voltages shows that the damage behaviours are quite different: the low gate voltage stress results in an increase in transconductance, while the NBTI-dominated high gate voltage and high temperature stress causes a decrease in transconductance. It is concluded that this can be a major source of hot carrier damage at elevated temperatures and high gate voltage stressing of p-channel metal-oxide-semiconductor field-effect transistors (PMOSFETs). We demonstrate a novel mode of NBTI-enhanced hot carrier degradation in PMOSFETs. A novel method to decouple the actions of NBTI from that of hot carriers is also presented.
文摘A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.
文摘Device physics research for submicron and deep submicron space microelectronics devices and integrated circuits will be described in three topics.1.Thin film submicron and deep submicron SOS / CMOS devices and integrated circuits.2.Deep submicron LDD CMOS devices and integrated circuits.3.C band and Ku band microwave GaAs MESFET and III-V compound hetrojunction HEM T and HBT devices and integrated circuits.
文摘To compare pharmacokinetic behaviors of nitrendipine submicron emulsion with nitrendipine solution following intravenous administration in rats.The plasma concentrations were analyzed by ultra-performance liquid chromatography coupled with tandem mass spectrometry detection(UPLC-MS/MS)through a new validated method.The pharmacokinetic parameters of the nitrendipine submicron emulsion and nitrendipine solution were as follows:AUC_(0-t) 900.76±186.59 versus 687.08±66.24 ng h/ml,C_(max) 854.54±159.48 versus 610.59±235.99 ng/ml,t_(1/2)2.37±1.99 versus 2.80±2.69 h.The relative bioavailability of nitrendipine submicron emulsion to nitrendipine solution was 131.4±11.3%.The developed methods could meet the requirements of bioanalysis.Compared to the solution injection,intravenous submicron emulsion presents higher systematic exposure which can help to improve the therapeutic efficacy.