Tuning the charge carrier concentration is imperative to optimize the thermoelectric(TE)performance of a material.For BiCuSeO based oxyselenides,doping efforts have been limited to optimizing the carrier concentration...Tuning the charge carrier concentration is imperative to optimize the thermoelectric(TE)performance of a material.For BiCuSeO based oxyselenides,doping efforts have been limited to optimizing the carrier concentration.In the present work,dual-doping of In and Pb at Bi site is introduced for p-type BiCuSeO to realize the electric transport channels with intricate band characteristics to improve the power factor(PF).Herein,the impurity resonant state is realized via doping of resonant dopant In over Pb,where Pb comes forward to optimize the Fermi energy in the dual-doped BiCuSeO system to divulge the significance of complex electronic structure.The manifold roles of dual-doping are used to adjust the elevation of the PF due to the significant enhancement in electrical properties.Thus,the combined experimental and theoretical study shows that the In/Pb dual doping at Bi sites gently reduces bandgap,introduces resonant doping states with shifting down the Fermi level into valence band(VB)with a larger density of state,and thus causes to increase the carrier concentration and effective mass(m*),which are favorable to enhance the electronic transport significantly.As a result,both improved ZTmax=0.87(at 873 K)and high ZTave=0.5(at 300–873 K)are realized for InyBi(1−x)−yPbxCuSeO(where x=0.06 and y=0.04)system.The obtained results successfully demonstrate the effectiveness of the selective dual doping with resonant dopant inducing band manipulation and carrier engineering that can unlock new prospects to develop high TE materials.展开更多
The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte Carlo simulations.The magnetizations,specific heat values,and magnetic entropies are obtained for ...The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte Carlo simulations.The magnetizations,specific heat values,and magnetic entropies are obtained for different exchange interactions and external magnetic fields.The adiabatic temperature is obtained.The transition temperature is deduced.The relative cooling power is established with a fixed value of exchange interaction.According to the master curve behaviors for the temperature dependence of △S_m^（max） predicted for different maximum fields,in this work it is confirmed that the paramagnetic-ferromagnetic phase transition observed for our sample is of a second order.The near room-temperature interaction and the superexchange interaction between Ni and Mn are shown to be due to the ferromagnetism of LNMO.展开更多
An M-type Rb^(87) atomic system is proposed for one-dimensional atom microscopy under the condition of Electromagnetically Induced Transparency.Super-localization of the atom in the absorption spectrum while its deloc...An M-type Rb^(87) atomic system is proposed for one-dimensional atom microscopy under the condition of Electromagnetically Induced Transparency.Super-localization of the atom in the absorption spectrum while its delocalization in the dispersion spectrum is observed due to the dual superposition effect of the resonant Reids.The observed minimum uncertainty peaks will find important applications in Laser cooling,creating focused atom beams,atom nanolithography,and in measurement of the center-of-mass wave function of moving atoms.展开更多
The brain tumour is the mass where some tissues become old or damaged,but they do not die or not leave their space.Mainly brain tumour masses occur due to malignant masses.These tissues must die so that new tissues ar...The brain tumour is the mass where some tissues become old or damaged,but they do not die or not leave their space.Mainly brain tumour masses occur due to malignant masses.These tissues must die so that new tissues are allowed to be born and take their place.Tumour segmentation is a complex and time-taking problem due to the tumour’s size,shape,and appearance variation.Manually finding such masses in the brain by analyzing Magnetic Resonance Images(MRI)is a crucial task for experts and radiologists.Radiologists could not work for large volume images simultaneously,and many errors occurred due to overwhelming image analysis.The main objective of this research study is the segmentation of tumors in brain MRI images with the help of digital image processing and deep learning approaches.This research study proposed an automatic model for tumor segmentation in MRI images.The proposed model has a few significant steps,which first apply the pre-processing method for the whole dataset to convert Neuroimaging Informatics Technology Initiative(NIFTI)volumes into the 3D NumPy array.In the second step,the proposed model adopts U-Net deep learning segmentation algorithm with an improved layered structure and sets the updated parameters.In the third step,the proposed model uses state-of-the-art Medical Image Computing and Computer-Assisted Intervention(MICCAI)BRATS 2018 dataset withMRI modalities such as T1,T1Gd,T2,and Fluidattenuated inversion recovery(FLAIR).Tumour types in MRI images are classified according to the tumour masses.Labelling of these masses carried by state-of-the-art approaches such that the first is enhancing tumour(label 4),edema(label 2),necrotic and non-enhancing tumour core(label 1),and the remaining region is label 0 such that edema(whole tumour),necrosis and active.The proposed model is evaluated and gets the Dice Coefficient(DSC)value for High-grade glioma(HGG)volumes for their test set-a,test set-b,and test set-c 0.9795, 0.9855 and 0.9793, respectively. DSC value for the Low-gradeglioma (LGG) volum展开更多
In Vitro-In Vivo antidiabetic effect of Pleurotus florida mycelia was evaluated using enzymes,yeast cell and in streptozotocin induced type 2 diabetic(T2D)animal model.P.florida mycelia was prepared by submerged ferme...In Vitro-In Vivo antidiabetic effect of Pleurotus florida mycelia was evaluated using enzymes,yeast cell and in streptozotocin induced type 2 diabetic(T2D)animal model.P.florida mycelia was prepared by submerged fermentation process.The fungal biomass was organically extracted using mixture of ethanol and water.Highest extractives yield of 14.3%w/w was obtained in hydroalcoholic solvent with dielectric constant-δvalue of 78.2(EX78).P.florida mycelia extract(EX 78)shows higher antioxidant power with 86.87%free radical scavenging activity and with 75.29 reducing power.In-vitroα-amylase inhibition,α-glucosidase inhibition and glucose uptake activity of EX 78 shows higher effectiveness.The P.florida mycelia extract(EX 78)is also found to be effective in controlling of blood glucose and insulin level in streptozotocin-nicotinamide induced T2D animals.The blood glucose was reduced to 216±6.21 mg/dl from 357±0.34 mg/dl and the insulin level was increased to 0.423±0.006 ng per mL from 0.164±0.03 ng/mL in P.florida treated animals.The higher fatty acids,C20-eicosane;C24-tetracosane and C30-squalene present in P.florida mycelium extract was found to be effective in inhibiting human intestinalα-glucosidase and pancreaticα-amylase.The P.florida mushroom is found to be effective in controlling high blood glucose elevated liver and cardiac enzymes.Consumption of this mushroom is suitable for controlling blood glucose level in person with hyperglycaemia.展开更多
The magnetic properties of inverse ferrite Fe_(3+) Fe_(3+)Co_(2+) O^(2-)_4, Fe^(3+) Fe^(3+)Cu^(2+) O^2_(-4), Fe^(3+) Fe^(3+)Fe^(2+) O^2_(-4),and Fe^(3+) Fe^(3+)Ni^(2+) O^(2-)_4spinels have been studied using Monte Car...The magnetic properties of inverse ferrite Fe_(3+) Fe_(3+)Co_(2+) O^(2-)_4, Fe^(3+) Fe^(3+)Cu^(2+) O^2_(-4), Fe^(3+) Fe^(3+)Fe^(2+) O^2_(-4),and Fe^(3+) Fe^(3+)Ni^(2+) O^(2-)_4spinels have been studied using Monte Carlo simulation. We have also calculated the critical and Curie Weiss temperatures from the thermal magnetizations and inverse of magnetic susceptibilities for each system.Magnetic hysteresis cycles have been found for the four systems. Finally, we found the critical exponents associated with magnetization, magnetic susceptibility, and external magnetic field. Our results of critical and Curie Weiss temperatures are similar to those obtained by experiment results. The critical exponents are similar to those of known 3 D-Ising model.展开更多
Owing to the unique features,such as mechanically robust,low-toxic,high stability,and high thermoelectric performance,CoSb_(3)-based skutterudite materials are among art-of-the state thermoelectric candidates.In this ...Owing to the unique features,such as mechanically robust,low-toxic,high stability,and high thermoelectric performance,CoSb_(3)-based skutterudite materials are among art-of-the state thermoelectric candidates.In this work,we develop a facile in-situ method for the growth of well-crystallinity(Ag,Sn)co-doped CoSb_(3)thin films.This preparation method can efficiently control the dopant concentration and distribution in the thin films.Both the density functional theory calculation and the experimental results suggest that Sn and Ag dopants trend to enter the lattice and preferentially fill interstitial sites.Additionally,band structure calculation results suggest that the Fermi level moves into the conduction bands due to co-doping and eventually induces the increased electrical conductivity,which agrees with the optimization of carrier concentration.Moreover,an increase in the density of state after co-doping is responsible for the increased Seebeck coefficient.As a result,the power factors of(Ag,Sn)co-doped CoSb_(3)thin films are greatly enhanced,and the maximum power factor achieves over 0.3 m W m^(-1)K^(-2)at 623 K,which is almost two times than that of the un-doped CoSb_(3)film.Multiple microstructures,including Sb vacancies and Ag/Sn interstitial atoms as point defects,and a high density of lattice distortions coupled with nano-sized Ag-rich grains,lead to all scale phonon scatterings.As a result,a reduced thermal conductivity of~0.28 W m^(-1)K^(-1)and a maximum ZT of~0.52 at 623 K are obtained from(Ag,Sn)co-doped CoSb_(3)thin films.This study indicates our facile in-situ growth can be used to develop high-performance dual doped CoSb_(3)thins.展开更多
Modern autonomous vehicles are getting progressively popular and increasingly getting closer to the core of future development in transportation field.However,there is no reliable authentication mechanism for the unma...Modern autonomous vehicles are getting progressively popular and increasingly getting closer to the core of future development in transportation field.However,there is no reliable authentication mechanism for the unmanned vehicle communication system,this phenomenon draws attention about the security of autonomous vehicles of people in all aspects.Physical Unclonable Function(PUF)circuits is light-weight,and it can product unique and unpredictable digital signature utilizing the manufacturing variations occur in each die and these exact silicon features cannot be recreated theoretically.Considering security issues of communication between Electronic Control Units(ECUs)in vehicles,we propose a novel delay-based PUF circuit using all the available logical components in every two-slice within Configurable Logic Blocks(CLBs)in Field Programmable Gate Array(FPGA)chips,which is significantly suitable for circuit authentication in ECUs of autonomous vehicles and is a significant improvement over the usual arbiter PUF in resource occupation in FPGA chips,that is to say it can get stronger resistance to security risks with less logic resource overhead.Our PUF design is resource efficient so that it can exactly be applied to the source-constrained devices such as in-vehicle ECUs.It effectively reduce the risk of the messages delivered between ECUs being tampered and then vehicle be illegally controlled by adversary.We simulated the proposed PUF circuit in simulator and implemented it on Xilinx boards under different conditions to obtain experimental results,the analyzed result proves that the proposed PUF satisfies the properties of Uniqueness and Stability.Finally,the ECUs authentication mechanism utilizing our PUF circuit is introduced.展开更多
The self-consistent ab initio calculations based on the density functional theory approach using the full potential linear augmented plane wave method are performed to investigate both the electronic and magnetic prop...The self-consistent ab initio calculations based on the density functional theory approach using the full potential linear augmented plane wave method are performed to investigate both the electronic and magnetic properties of the NiFe compound. Polarized spin within the framework of the ferromagnetic state between magnetic ions is considered. Also, magnetic moments considered to lie along （001） axes are computed. The Monte Carlo simulation is used to study the magnetic properties of NiFe. The transition temperature To, hysteresis loop, coercive field and remanent magnetization of the NiFe compound are obtained using the Monte Carlo simulation.展开更多
Alumina silicate powder which is extracted from the obsolete spark plug NGK (insulator part as a filler) has been used to produce epoxy/alumina silicate composite. The dielectric behavior of the composite materials (e...Alumina silicate powder which is extracted from the obsolete spark plug NGK (insulator part as a filler) has been used to produce epoxy/alumina silicate composite. The dielectric behavior of the composite materials (epoxy resin-alumina silicate NGK) is analyzed as a function of the filler content, temperature and frequency. AC conductivity and impedance are also studied. The results show that the permittivity, dielectric loss and loss tangent for all composites increase with increasing alumina silicate NGK filler content.展开更多
The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each a...The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each as a function of layer thickness for different values of exchange interaction. The exchange interaction in each layer within the interface and the crystal field in the unit cell are studied. The magnetic coercive fields and magnetization remnants are obtained for different values of exchange interaction, different values of temperature and crystal field with fixed values of physical parameters.展开更多
A new ephemeris,period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this study.Light curves of the system taken in BVRI filters from two observatories,in Australi...A new ephemeris,period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this study.Light curves of the system taken in BVRI filters from two observatories,in Australia and Argentina,were modeled using the Wilson-Devinney code.The results of this analysis demonstrate that BF Pav is a contact binary system with a photometric mass ratio q=1.460 ± 0.014,a fillout factor f=12.5%,an inclination of 87.97 ± 0.45 deg and a cold spot on the secondary component.By applying the distance modulus formula,the distance of BF Pav was calculated to be d=268 ± 18 pc which is in good agreement with the Gaia EDR3 distance.We obtain an orbital period increase at a rate of 0.142 s century-1 due to a quadratic trend in the O-C diagram.Also,an alternative sudden period jump probably occurred which could be interpreted as a rapid mass transfer from the lower mass star to its companion of about ΔM=2.45 × 10-6 M⊙.Furthermore,there is an oscillatory behavior with a period of 18.3±0.3 yr.Since BF Pav does not seem to have significant magnetic activity,this behavior could be interpreted as the light-time effect caused by an undetected third body in this system.In this case,the probability for the third body to be a low mass star with M≥ 0.075 M⊙or a brown dwarf is 5.4% and 94.6% respectively.If we assume i’=90°,a3=8.04±0.33 AU.The mass of the secondary component was also determined following two different methods which result close to each other.展开更多
Spectral hole burning is investigated in an optical medium in the presence of Doppler broadening and Kerr nonlinearity. The Kerr nonlinearity generates coherent hole burning in the absorption spectrum. The higher orde...Spectral hole burning is investigated in an optical medium in the presence of Doppler broadening and Kerr nonlinearity. The Kerr nonlinearity generates coherent hole burning in the absorption spectrum. The higher order Kerr nonlinearity enhances the typical lamb dip of the hole. Normal dispersion in the hole burning region while Steep anomalous dispersion between the two hole burning regions also enhances with higher order Kerr effect. A large phase shift creates large delay or advancement in the pulse propagation while no distortion is observed in the pulse. These results provide significant steps to improve optical memory, telecom devices, preservation of information and image quality.展开更多
In this study,we show how a static magnetic field can control photon-induced electron transport through a quantum dot system coupled to a photon cavity.The quantum dot system is connected to two electron reservoirs an...In this study,we show how a static magnetic field can control photon-induced electron transport through a quantum dot system coupled to a photon cavity.The quantum dot system is connected to two electron reservoirs and exposed to an external perpendicular static magnetic field.The propagation of electrons through the system is thus influenced by the static magnetic and the dynamic photon fields.It is observed that the photon cavity forms photon replica states controlling electron transport in the system.If the photon field has more energy than the cyclotron energy,then the photon field is dominant in the electron transport.Consequently,the electron transport is enhanced due to activation of photon replica states.By contrast,the electron transport is suppressed in the system when the photon energy is smaller than the cyclotron energy.展开更多
The intrinsic ferromagnetism of CoBr2 bulk was investigated using DFT(density functional theory)combined with the full potential linear augmented plane wave method and Monte Carlo simulations.The ground state of CoBr2...The intrinsic ferromagnetism of CoBr2 bulk was investigated using DFT(density functional theory)combined with the full potential linear augmented plane wave method and Monte Carlo simulations.The ground state of CoBr2 exhibits ferromagnetic behavior and a semiconductor character.We used the generalized gradient approximation(GGA)and GGA+U(Hubbard correction)approximations to determinate the magnetic moment.The magnetic moment reached the experimental value and was in good agreement with the other theoretical values.The value obtained was used as an input to a Monte Carlo study to calculate the thermal magnetization and magnetic hysteresis cycles.Ferromagnetic behavior was observed and was found to be due to an positive exchange interaction.These results lead us to believe that this material could be a promising spintronic material.展开更多
We demonstrate the possibility of creating a time gap in the slow light based on spectral hole burning in a fourlevel Doppler broadened sodium atomic system. A time gap is also observed between the slow and the fast l...We demonstrate the possibility of creating a time gap in the slow light based on spectral hole burning in a fourlevel Doppler broadened sodium atomic system. A time gap is also observed between the slow and the fast light in the hole burning region and near the burnt hole region, respectively. A cloaking time gap is attained in microseconds and no distortion is observed in the transmitted pulse. The width of the time gap is observed to vary with the inverse Doppler effect in this system. Our results may provide a way to create multiple time gaps for a temporal cloak.展开更多
Renewable energy is a kind of energy that comes from natural sources like water, sunlight, wind and so on. Water electrolysis is currently the most dominant technology used for hydrogen production from renewable sourc...Renewable energy is a kind of energy that comes from natural sources like water, sunlight, wind and so on. Water electrolysis is currently the most dominant technology used for hydrogen production from renewable sources because of high energy conversion efficiency. In this present work, the effect of NaHCO3 via electrolysis?was studied. Stainless steel is chosen to be as the electrode and different concentration of NaHCO3 are used as alkaline solutions in electrolysis system. The rates of hydrogen gas produced using different concentration of NaHCO3 and pH value of every sample were measured. The experimental results that the performance of water electrolysis was highly affected by NaHCO3, the rate of hydrogen gas showed that 0.4 M of NaHCO3 and 65 ml/min at pH 8.2 are the best amount.展开更多
The number of mobile devices accessing wireless networks isskyrocketing due to the rapid advancement of sensors and wireless communicationtechnology. In the upcoming years, it is anticipated that mobile datatraffic wo...The number of mobile devices accessing wireless networks isskyrocketing due to the rapid advancement of sensors and wireless communicationtechnology. In the upcoming years, it is anticipated that mobile datatraffic would rise even more. The development of a new cellular networkparadigm is being driven by the Internet of Things, smart homes, and moresophisticated applications with greater data rates and latency requirements.Resources are being used up quickly due to the steady growth of smartphonedevices andmultimedia apps. Computation offloading to either several distantclouds or close mobile devices has consistently improved the performance ofmobile devices. The computation latency can also be decreased by offloadingcomputing duties to edge servers with a specific level of computing power.Device-to-device (D2D) collaboration can assist in processing small-scaleactivities that are time-sensitive in order to further reduce task delays. The taskoffloading performance is drastically reduced due to the variation of differentperformance capabilities of edge nodes. Therefore, this paper addressed thisproblem and proposed a new method for D2D communication. In thismethod, the time delay is reduced by enabling the edge nodes to exchangedata samples. Simulation results show that the proposed algorithm has betterperformance than traditional algorithm.展开更多
基金Present work was supported by Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515110107 and 2020A1515010515)the National Natural Science Foundation of China(No.11604212)。
文摘Tuning the charge carrier concentration is imperative to optimize the thermoelectric(TE)performance of a material.For BiCuSeO based oxyselenides,doping efforts have been limited to optimizing the carrier concentration.In the present work,dual-doping of In and Pb at Bi site is introduced for p-type BiCuSeO to realize the electric transport channels with intricate band characteristics to improve the power factor(PF).Herein,the impurity resonant state is realized via doping of resonant dopant In over Pb,where Pb comes forward to optimize the Fermi energy in the dual-doped BiCuSeO system to divulge the significance of complex electronic structure.The manifold roles of dual-doping are used to adjust the elevation of the PF due to the significant enhancement in electrical properties.Thus,the combined experimental and theoretical study shows that the In/Pb dual doping at Bi sites gently reduces bandgap,introduces resonant doping states with shifting down the Fermi level into valence band(VB)with a larger density of state,and thus causes to increase the carrier concentration and effective mass(m*),which are favorable to enhance the electronic transport significantly.As a result,both improved ZTmax=0.87(at 873 K)and high ZTave=0.5(at 300–873 K)are realized for InyBi(1−x)−yPbxCuSeO(where x=0.06 and y=0.04)system.The obtained results successfully demonstrate the effectiveness of the selective dual doping with resonant dopant inducing band manipulation and carrier engineering that can unlock new prospects to develop high TE materials.
文摘The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte Carlo simulations.The magnetizations,specific heat values,and magnetic entropies are obtained for different exchange interactions and external magnetic fields.The adiabatic temperature is obtained.The transition temperature is deduced.The relative cooling power is established with a fixed value of exchange interaction.According to the master curve behaviors for the temperature dependence of △S_m^（max） predicted for different maximum fields,in this work it is confirmed that the paramagnetic-ferromagnetic phase transition observed for our sample is of a second order.The near room-temperature interaction and the superexchange interaction between Ni and Mn are shown to be due to the ferromagnetism of LNMO.
基金supported by the Higher Education Commission (HEC) of Pakistan
文摘An M-type Rb^(87) atomic system is proposed for one-dimensional atom microscopy under the condition of Electromagnetically Induced Transparency.Super-localization of the atom in the absorption spectrum while its delocalization in the dispersion spectrum is observed due to the dual superposition effect of the resonant Reids.The observed minimum uncertainty peaks will find important applications in Laser cooling,creating focused atom beams,atom nanolithography,and in measurement of the center-of-mass wave function of moving atoms.
文摘The brain tumour is the mass where some tissues become old or damaged,but they do not die or not leave their space.Mainly brain tumour masses occur due to malignant masses.These tissues must die so that new tissues are allowed to be born and take their place.Tumour segmentation is a complex and time-taking problem due to the tumour’s size,shape,and appearance variation.Manually finding such masses in the brain by analyzing Magnetic Resonance Images(MRI)is a crucial task for experts and radiologists.Radiologists could not work for large volume images simultaneously,and many errors occurred due to overwhelming image analysis.The main objective of this research study is the segmentation of tumors in brain MRI images with the help of digital image processing and deep learning approaches.This research study proposed an automatic model for tumor segmentation in MRI images.The proposed model has a few significant steps,which first apply the pre-processing method for the whole dataset to convert Neuroimaging Informatics Technology Initiative(NIFTI)volumes into the 3D NumPy array.In the second step,the proposed model adopts U-Net deep learning segmentation algorithm with an improved layered structure and sets the updated parameters.In the third step,the proposed model uses state-of-the-art Medical Image Computing and Computer-Assisted Intervention(MICCAI)BRATS 2018 dataset withMRI modalities such as T1,T1Gd,T2,and Fluidattenuated inversion recovery(FLAIR).Tumour types in MRI images are classified according to the tumour masses.Labelling of these masses carried by state-of-the-art approaches such that the first is enhancing tumour(label 4),edema(label 2),necrotic and non-enhancing tumour core(label 1),and the remaining region is label 0 such that edema(whole tumour),necrosis and active.The proposed model is evaluated and gets the Dice Coefficient(DSC)value for High-grade glioma(HGG)volumes for their test set-a,test set-b,and test set-c 0.9795, 0.9855 and 0.9793, respectively. DSC value for the Low-gradeglioma (LGG) volum
基金The authors would like to thank Professor Gerard Abraham,ICAR-Indian Agricultural Research Institute,New Delhi for performing GC-MS analysis of the samples.Dr.Syed Obaidur Rahman,Department of Pharmacology,SPER,Jamia Hamdard.New Delhi for assisting in in-vivo study.
文摘In Vitro-In Vivo antidiabetic effect of Pleurotus florida mycelia was evaluated using enzymes,yeast cell and in streptozotocin induced type 2 diabetic(T2D)animal model.P.florida mycelia was prepared by submerged fermentation process.The fungal biomass was organically extracted using mixture of ethanol and water.Highest extractives yield of 14.3%w/w was obtained in hydroalcoholic solvent with dielectric constant-δvalue of 78.2(EX78).P.florida mycelia extract(EX 78)shows higher antioxidant power with 86.87%free radical scavenging activity and with 75.29 reducing power.In-vitroα-amylase inhibition,α-glucosidase inhibition and glucose uptake activity of EX 78 shows higher effectiveness.The P.florida mycelia extract(EX 78)is also found to be effective in controlling of blood glucose and insulin level in streptozotocin-nicotinamide induced T2D animals.The blood glucose was reduced to 216±6.21 mg/dl from 357±0.34 mg/dl and the insulin level was increased to 0.423±0.006 ng per mL from 0.164±0.03 ng/mL in P.florida treated animals.The higher fatty acids,C20-eicosane;C24-tetracosane and C30-squalene present in P.florida mycelium extract was found to be effective in inhibiting human intestinalα-glucosidase and pancreaticα-amylase.The P.florida mushroom is found to be effective in controlling high blood glucose elevated liver and cardiac enzymes.Consumption of this mushroom is suitable for controlling blood glucose level in person with hyperglycaemia.
文摘The magnetic properties of inverse ferrite Fe_(3+) Fe_(3+)Co_(2+) O^(2-)_4, Fe^(3+) Fe^(3+)Cu^(2+) O^2_(-4), Fe^(3+) Fe^(3+)Fe^(2+) O^2_(-4),and Fe^(3+) Fe^(3+)Ni^(2+) O^(2-)_4spinels have been studied using Monte Carlo simulation. We have also calculated the critical and Curie Weiss temperatures from the thermal magnetizations and inverse of magnetic susceptibilities for each system.Magnetic hysteresis cycles have been found for the four systems. Finally, we found the critical exponents associated with magnetization, magnetic susceptibility, and external magnetic field. Our results of critical and Curie Weiss temperatures are similar to those obtained by experiment results. The critical exponents are similar to those of known 3 D-Ising model.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2020A1515010515 and 2019A1515110107)National Natural Science Foundation of China(11604212)Australian Research Council。
文摘Owing to the unique features,such as mechanically robust,low-toxic,high stability,and high thermoelectric performance,CoSb_(3)-based skutterudite materials are among art-of-the state thermoelectric candidates.In this work,we develop a facile in-situ method for the growth of well-crystallinity(Ag,Sn)co-doped CoSb_(3)thin films.This preparation method can efficiently control the dopant concentration and distribution in the thin films.Both the density functional theory calculation and the experimental results suggest that Sn and Ag dopants trend to enter the lattice and preferentially fill interstitial sites.Additionally,band structure calculation results suggest that the Fermi level moves into the conduction bands due to co-doping and eventually induces the increased electrical conductivity,which agrees with the optimization of carrier concentration.Moreover,an increase in the density of state after co-doping is responsible for the increased Seebeck coefficient.As a result,the power factors of(Ag,Sn)co-doped CoSb_(3)thin films are greatly enhanced,and the maximum power factor achieves over 0.3 m W m^(-1)K^(-2)at 623 K,which is almost two times than that of the un-doped CoSb_(3)film.Multiple microstructures,including Sb vacancies and Ag/Sn interstitial atoms as point defects,and a high density of lattice distortions coupled with nano-sized Ag-rich grains,lead to all scale phonon scatterings.As a result,a reduced thermal conductivity of~0.28 W m^(-1)K^(-1)and a maximum ZT of~0.52 at 623 K are obtained from(Ag,Sn)co-doped CoSb_(3)thin films.This study indicates our facile in-situ growth can be used to develop high-performance dual doped CoSb_(3)thins.
基金supported by the Key Scientific and Technological Innovation Team of the Shaanxi Province,China,under Grant No.2017KCT-29,and the Key Research Item for the Industry Shaanxi Province under Grant No.2018GY-136.
文摘Modern autonomous vehicles are getting progressively popular and increasingly getting closer to the core of future development in transportation field.However,there is no reliable authentication mechanism for the unmanned vehicle communication system,this phenomenon draws attention about the security of autonomous vehicles of people in all aspects.Physical Unclonable Function(PUF)circuits is light-weight,and it can product unique and unpredictable digital signature utilizing the manufacturing variations occur in each die and these exact silicon features cannot be recreated theoretically.Considering security issues of communication between Electronic Control Units(ECUs)in vehicles,we propose a novel delay-based PUF circuit using all the available logical components in every two-slice within Configurable Logic Blocks(CLBs)in Field Programmable Gate Array(FPGA)chips,which is significantly suitable for circuit authentication in ECUs of autonomous vehicles and is a significant improvement over the usual arbiter PUF in resource occupation in FPGA chips,that is to say it can get stronger resistance to security risks with less logic resource overhead.Our PUF design is resource efficient so that it can exactly be applied to the source-constrained devices such as in-vehicle ECUs.It effectively reduce the risk of the messages delivered between ECUs being tampered and then vehicle be illegally controlled by adversary.We simulated the proposed PUF circuit in simulator and implemented it on Xilinx boards under different conditions to obtain experimental results,the analyzed result proves that the proposed PUF satisfies the properties of Uniqueness and Stability.Finally,the ECUs authentication mechanism utilizing our PUF circuit is introduced.
文摘The self-consistent ab initio calculations based on the density functional theory approach using the full potential linear augmented plane wave method are performed to investigate both the electronic and magnetic properties of the NiFe compound. Polarized spin within the framework of the ferromagnetic state between magnetic ions is considered. Also, magnetic moments considered to lie along （001） axes are computed. The Monte Carlo simulation is used to study the magnetic properties of NiFe. The transition temperature To, hysteresis loop, coercive field and remanent magnetization of the NiFe compound are obtained using the Monte Carlo simulation.
文摘Alumina silicate powder which is extracted from the obsolete spark plug NGK (insulator part as a filler) has been used to produce epoxy/alumina silicate composite. The dielectric behavior of the composite materials (epoxy resin-alumina silicate NGK) is analyzed as a function of the filler content, temperature and frequency. AC conductivity and impedance are also studied. The results show that the permittivity, dielectric loss and loss tangent for all composites increase with increasing alumina silicate NGK filler content.
文摘The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each as a function of layer thickness for different values of exchange interaction. The exchange interaction in each layer within the interface and the crystal field in the unit cell are studied. The magnetic coercive fields and magnetization remnants are obtained for different values of exchange interaction, different values of temperature and crystal field with fixed values of physical parameters.
基金based on the Binary Systems of South and North Project (http:// bsnp.info)。
文摘A new ephemeris,period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this study.Light curves of the system taken in BVRI filters from two observatories,in Australia and Argentina,were modeled using the Wilson-Devinney code.The results of this analysis demonstrate that BF Pav is a contact binary system with a photometric mass ratio q=1.460 ± 0.014,a fillout factor f=12.5%,an inclination of 87.97 ± 0.45 deg and a cold spot on the secondary component.By applying the distance modulus formula,the distance of BF Pav was calculated to be d=268 ± 18 pc which is in good agreement with the Gaia EDR3 distance.We obtain an orbital period increase at a rate of 0.142 s century-1 due to a quadratic trend in the O-C diagram.Also,an alternative sudden period jump probably occurred which could be interpreted as a rapid mass transfer from the lower mass star to its companion of about ΔM=2.45 × 10-6 M⊙.Furthermore,there is an oscillatory behavior with a period of 18.3±0.3 yr.Since BF Pav does not seem to have significant magnetic activity,this behavior could be interpreted as the light-time effect caused by an undetected third body in this system.In this case,the probability for the third body to be a low mass star with M≥ 0.075 M⊙or a brown dwarf is 5.4% and 94.6% respectively.If we assume i’=90°,a3=8.04±0.33 AU.The mass of the secondary component was also determined following two different methods which result close to each other.
基金Supported by Higher Education Commission(HEC)of Pakistan
文摘Spectral hole burning is investigated in an optical medium in the presence of Doppler broadening and Kerr nonlinearity. The Kerr nonlinearity generates coherent hole burning in the absorption spectrum. The higher order Kerr nonlinearity enhances the typical lamb dip of the hole. Normal dispersion in the hole burning region while Steep anomalous dispersion between the two hole burning regions also enhances with higher order Kerr effect. A large phase shift creates large delay or advancement in the pulse propagation while no distortion is observed in the pulse. These results provide significant steps to improve optical memory, telecom devices, preservation of information and image quality.
基金the Icelandic Research and Instruments Funds for financial supportthe Research Fund of the University of Iceland
文摘In this study,we show how a static magnetic field can control photon-induced electron transport through a quantum dot system coupled to a photon cavity.The quantum dot system is connected to two electron reservoirs and exposed to an external perpendicular static magnetic field.The propagation of electrons through the system is thus influenced by the static magnetic and the dynamic photon fields.It is observed that the photon cavity forms photon replica states controlling electron transport in the system.If the photon field has more energy than the cyclotron energy,then the photon field is dominant in the electron transport.Consequently,the electron transport is enhanced due to activation of photon replica states.By contrast,the electron transport is suppressed in the system when the photon energy is smaller than the cyclotron energy.
文摘The intrinsic ferromagnetism of CoBr2 bulk was investigated using DFT(density functional theory)combined with the full potential linear augmented plane wave method and Monte Carlo simulations.The ground state of CoBr2 exhibits ferromagnetic behavior and a semiconductor character.We used the generalized gradient approximation(GGA)and GGA+U(Hubbard correction)approximations to determinate the magnetic moment.The magnetic moment reached the experimental value and was in good agreement with the other theoretical values.The value obtained was used as an input to a Monte Carlo study to calculate the thermal magnetization and magnetic hysteresis cycles.Ferromagnetic behavior was observed and was found to be due to an positive exchange interaction.These results lead us to believe that this material could be a promising spintronic material.
基金supported by the Higher Education Commission(HEC)of Pakistan
文摘We demonstrate the possibility of creating a time gap in the slow light based on spectral hole burning in a fourlevel Doppler broadened sodium atomic system. A time gap is also observed between the slow and the fast light in the hole burning region and near the burnt hole region, respectively. A cloaking time gap is attained in microseconds and no distortion is observed in the transmitted pulse. The width of the time gap is observed to vary with the inverse Doppler effect in this system. Our results may provide a way to create multiple time gaps for a temporal cloak.
文摘Renewable energy is a kind of energy that comes from natural sources like water, sunlight, wind and so on. Water electrolysis is currently the most dominant technology used for hydrogen production from renewable sources because of high energy conversion efficiency. In this present work, the effect of NaHCO3 via electrolysis?was studied. Stainless steel is chosen to be as the electrode and different concentration of NaHCO3 are used as alkaline solutions in electrolysis system. The rates of hydrogen gas produced using different concentration of NaHCO3 and pH value of every sample were measured. The experimental results that the performance of water electrolysis was highly affected by NaHCO3, the rate of hydrogen gas showed that 0.4 M of NaHCO3 and 65 ml/min at pH 8.2 are the best amount.
文摘The number of mobile devices accessing wireless networks isskyrocketing due to the rapid advancement of sensors and wireless communicationtechnology. In the upcoming years, it is anticipated that mobile datatraffic would rise even more. The development of a new cellular networkparadigm is being driven by the Internet of Things, smart homes, and moresophisticated applications with greater data rates and latency requirements.Resources are being used up quickly due to the steady growth of smartphonedevices andmultimedia apps. Computation offloading to either several distantclouds or close mobile devices has consistently improved the performance ofmobile devices. The computation latency can also be decreased by offloadingcomputing duties to edge servers with a specific level of computing power.Device-to-device (D2D) collaboration can assist in processing small-scaleactivities that are time-sensitive in order to further reduce task delays. The taskoffloading performance is drastically reduced due to the variation of differentperformance capabilities of edge nodes. Therefore, this paper addressed thisproblem and proposed a new method for D2D communication. In thismethod, the time delay is reduced by enabling the edge nodes to exchangedata samples. Simulation results show that the proposed algorithm has betterperformance than traditional algorithm.
