Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an...Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an empirical formula for porosity calculation from full diameter rhyolite core experiments with the matrix porosity formulas commonly used. We discuss the applicability of the empirical formula in fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Based on core analysis data, the error distribution of the calculated porosity of our empirical formula and the other porosity formulas in these reservoirs are given. The statistical error analysis indicates that the our empirical formula provides a higher precision than the other porosity formulas. When the porosity is between 1.5% and 15%, the acoustic experiment formula can be used not only for acidic volcanics but also in other fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Moreover, the formula can reduce the effects of borehole enlargement and rock alteration on porosity computation.展开更多
Intelligent computing paradigms have become increasingly important for the efficient processing of massive amounts of data.However,using traditional electronic devices to implement these intelligent paradigms is curre...Intelligent computing paradigms have become increasingly important for the efficient processing of massive amounts of data.However,using traditional electronic devices to implement these intelligent paradigms is currently mismatched and limited by their energy,area,and speed.Spintronics,which exploits the magnetic and electrical properties of electrons,could break through these limitations and bring new possibilities to electrical devices.In particular,the tunneling magnetoresistance effect,merging quantum and spintronics,enables spintronic devices to be compatible with standard integrated circuits with a magnetic tunnel junction(MTJ)design,showing great potential for implementing hardware-based intelligent frameworks.In this review,we introduce the specific capabilities of MTJs,including nonvolatility,stochasticity,plasticity,and nonlinearity,which are highly favorable in artificial intelligence algorithms.We then present how these devices could impact the development of intelligent computing,including in-memory computing,probabilistic computing,and neuromorphic computing.Finally,we discuss their challenges and perspectives in intelligent hardware implementations.展开更多
The dyeing temperature of natural dye lac red on two kinds of natural protein fibers was studied, and the interaction between dyestuff and fiber was discussed through thermodynamic study and density functional theory ...The dyeing temperature of natural dye lac red on two kinds of natural protein fibers was studied, and the interaction between dyestuff and fiber was discussed through thermodynamic study and density functional theory (DFT) calculation. The optimum temperature for lac red dyed silk was 60˚C and wool showed a better response at 90˚C. The thermodynamics study revealed good Nernst isotherm and Freundlich adsorption models respectively, and the lac dye adsorption processes were both spontaneous and exothermic. The potential interaction of Laccaic acid A with the external environment by electrostatic potential and atomic charge distribution was first explored. With molecular simulation, Laccaic acid A and glycine composed 8 stable complexes. Then, typical hydrogen bonds, bond length, and binding energy, etc. were analyzed. The results revealed lac red on silk and wool fabric mainly depended on the weak hydrogen bonds and van der Waals force which determined the low dye fastness.展开更多
Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have...Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have transitioned from focusing on the interface coupling features to achieving the manipulation and detection of AFMs.As AFMs are internally magnetic,taking full use of AFMs for information storage has been the main target of research.In this paper,we provide a comprehensive description of AFM spintronics applications from the interface coupling,read-out operations,and writing manipulations perspective.We examine the early use of AFMs in magnetic recordings and conventional magnetoresistive random-access memory(MRAM),and review the latest mechanisms of the manipulation and detection of AFMs.Finally,based on exchange bias(EB)manipulation,a high-performance EB-MRAM is introduced as the next generation of AFM-based memories,which provides an effective method for read-out and writing of AFMs and opens a new era for AFM spintronics.展开更多
The current-induced spin-orbit torque(SOT) is one of the most promising ways for high speed and low power spintronics devices. However, the mechanism of SOT driven magnetization reversal, especially the role of the fi...The current-induced spin-orbit torque(SOT) is one of the most promising ways for high speed and low power spintronics devices. However, the mechanism of SOT driven magnetization reversal, especially the role of the field-like torque(FLT), is still unclear. Here, we report the observed promotion and suppression of switching by FLT, which depends on the relative direction of FLT and spin polarization. Our results reveal that the FLT could modulate the switching speed and power consumption by affecting the work done by the damping-like torque, and leads two different reversal dynamical paths during the switching.Furthermore, the origin of incubation time in SOT induced switching is clarified simultaneously.展开更多
Hydraulic fracturing technique is widely used for methane drainage and has achieved good effects in numerous coal mines,but negative effects may occur as the fracturing fluids are absorbed into the coal seam.Gas wetta...Hydraulic fracturing technique is widely used for methane drainage and has achieved good effects in numerous coal mines,but negative effects may occur as the fracturing fluids are absorbed into the coal seam.Gas wettability alteration(GWA)technology can be used as it can enhance the gas and water mobility during dewatering process as a result of capillary pressure change.However,there have been few reported field tests in coal mines using GWA technology.This paper describes a pilot-scale field test in Xinjing coal mine,Yangquan,China.The fluorocarbon surfactants perfluorooctyl methacrylate monomer-containing polymethacrylate(PMP)was used to alter the wettability of coal seam to strong gas-wetness during the hydraulic fracturing process.The study focuses on the comparison of two boreholes(Boreholes#9 and#10)and one other borehole(Borehole#8)with and without using GWA approach.A well-defined monitoring program was established by measuring the dewatering volume of the fracturing fluid and the drainage volume of methane as well as the concentration.The field test results showed that the average methane drainage rates of Boreholes#9(39.28 m^(3)/d)and#10(51.04 m^(3)/d)with GWA treatment exceeded that of Borehole#8(21.09 m^(3)/d)without GWA treatment,with an increase of 86.3%and 142.1%,respectively.The average methane concentrations of Boreholes#9(4.05%)and#10(6.18%)were 64.6%and 151.2%higher than that of Borehole#8(2.46%),respectively.On the other hand,the dewatering ratio of Boreholes#9(4.36%)and#10(3.11%)was almost 19 times and 13 times greater than that of Borehole#8(0.22%).These field test results were in agreement with the experimental data.The significant increase in both methane concentration and dewatering ratio demonstrated that GWA technology could be applied for enhanced methane drainage in coal mines.Important lessons learned at Xinjing coal mine might be applied to other coal mines in China and elsewhere.展开更多
Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel ...Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel junctions(MTJs).The droplet nucleation is accompanied by power enhancement compared with its ferromagnetic resonance modes.The nucleation and stabilization of droplets are ascribed to the double-Co Fe B free-layer structure in the all-perpendicular MTJ,which provides a low Zhang-Li torque and a high pinning field.Our results enable better electrical sensitivity in fundamental studies of droplets and show that the droplets can be utilized in MTJ-based applications and materials science.展开更多
The distribution and characteristics of LDH isoenzymes in different tissues of 25spe-cies of vertebrats were comparativety analysed by discontinuous polyacrylamide gel diskelectrophoresis,combined with experiments on ...The distribution and characteristics of LDH isoenzymes in different tissues of 25spe-cies of vertebrats were comparativety analysed by discontinuous polyacrylamide gel diskelectrophoresis,combined with experiments on heat and urea inhibition.The result showed that indifferent tissues of Cienopharyngodon idellus,Carassius,ayratus,Trichiurus haumete and Miichihysmiiuy in addition to the distribution of LDH isoenzymes,composed of A and B subuits,a E4isoenzyme band,moving very fast to the positive pole,was detectedin the eye tissue of Trichiurushaumele and a F4 isoenzyme hand,moving very slow to the positive pole,was found in liver andkidney of Cienopharyngodon idellus.The A4 isoenzyme band was found in different tisseues ofPleuronichlhys cornulus,inhabiting on the bottom of the ocean.From the amphition to the mammal,with the exception of Hyta arboreu immaculata,Chinnemys reevesii,Trioyx sinensis,Gallus gallusdomeslicus and Corvus macrorhynchos,which have special electrophoretic behaviours.In展开更多
基金sponsored by the Science Research and Technology Development Project of Petrochina Company Limited "Well Logging Interpretation and Integrative Evaluation of the Complex Lithology"(Grant No.2008A-2705)
文摘Matrix porosity calculations of fractured and vuggy reservoirs, such as volcanics and weathered dolomite, are one of the problems urgently needed to solve in well-log evaluation. In this paper, we first compare the an empirical formula for porosity calculation from full diameter rhyolite core experiments with the matrix porosity formulas commonly used. We discuss the applicability of the empirical formula in fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Based on core analysis data, the error distribution of the calculated porosity of our empirical formula and the other porosity formulas in these reservoirs are given. The statistical error analysis indicates that the our empirical formula provides a higher precision than the other porosity formulas. When the porosity is between 1.5% and 15%, the acoustic experiment formula can be used not only for acidic volcanics but also in other fractured and vuggy reservoirs, such as intermediate-basic volcanics and weathered dolomite. Moreover, the formula can reduce the effects of borehole enlargement and rock alteration on porosity computation.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFB4400201,and 2022YFB440020)the National Natural Science Foundation of China(Grant Nos.92164206,62271026,and 62001014)the Academic Excellence Foundation of BUAA for PhD Students。
文摘Intelligent computing paradigms have become increasingly important for the efficient processing of massive amounts of data.However,using traditional electronic devices to implement these intelligent paradigms is currently mismatched and limited by their energy,area,and speed.Spintronics,which exploits the magnetic and electrical properties of electrons,could break through these limitations and bring new possibilities to electrical devices.In particular,the tunneling magnetoresistance effect,merging quantum and spintronics,enables spintronic devices to be compatible with standard integrated circuits with a magnetic tunnel junction(MTJ)design,showing great potential for implementing hardware-based intelligent frameworks.In this review,we introduce the specific capabilities of MTJs,including nonvolatility,stochasticity,plasticity,and nonlinearity,which are highly favorable in artificial intelligence algorithms.We then present how these devices could impact the development of intelligent computing,including in-memory computing,probabilistic computing,and neuromorphic computing.Finally,we discuss their challenges and perspectives in intelligent hardware implementations.
文摘The dyeing temperature of natural dye lac red on two kinds of natural protein fibers was studied, and the interaction between dyestuff and fiber was discussed through thermodynamic study and density functional theory (DFT) calculation. The optimum temperature for lac red dyed silk was 60˚C and wool showed a better response at 90˚C. The thermodynamics study revealed good Nernst isotherm and Freundlich adsorption models respectively, and the lac dye adsorption processes were both spontaneous and exothermic. The potential interaction of Laccaic acid A with the external environment by electrostatic potential and atomic charge distribution was first explored. With molecular simulation, Laccaic acid A and glycine composed 8 stable complexes. Then, typical hydrogen bonds, bond length, and binding energy, etc. were analyzed. The results revealed lac red on silk and wool fabric mainly depended on the weak hydrogen bonds and van der Waals force which determined the low dye fastness.
基金the National Key Research and Development Program of China(Grants No.2021YFB3601303,2021YFB3601300)the National Natural Science Foundation of China(Grants No.92164206,61904009,62001014 and 61627813)for their financial support of this work.
文摘Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have transitioned from focusing on the interface coupling features to achieving the manipulation and detection of AFMs.As AFMs are internally magnetic,taking full use of AFMs for information storage has been the main target of research.In this paper,we provide a comprehensive description of AFM spintronics applications from the interface coupling,read-out operations,and writing manipulations perspective.We examine the early use of AFMs in magnetic recordings and conventional magnetoresistive random-access memory(MRAM),and review the latest mechanisms of the manipulation and detection of AFMs.Finally,based on exchange bias(EB)manipulation,a high-performance EB-MRAM is introduced as the next generation of AFM-based memories,which provides an effective method for read-out and writing of AFMs and opens a new era for AFM spintronics.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2021YFB3601303, and 2021YFB3601300)the National Natural Science Foundation of China (Grant Nos. 92164206, 61904009, and 62001014) for their financial support of this work。
文摘The current-induced spin-orbit torque(SOT) is one of the most promising ways for high speed and low power spintronics devices. However, the mechanism of SOT driven magnetization reversal, especially the role of the field-like torque(FLT), is still unclear. Here, we report the observed promotion and suppression of switching by FLT, which depends on the relative direction of FLT and spin polarization. Our results reveal that the FLT could modulate the switching speed and power consumption by affecting the work done by the damping-like torque, and leads two different reversal dynamical paths during the switching.Furthermore, the origin of incubation time in SOT induced switching is clarified simultaneously.
文摘Hydraulic fracturing technique is widely used for methane drainage and has achieved good effects in numerous coal mines,but negative effects may occur as the fracturing fluids are absorbed into the coal seam.Gas wettability alteration(GWA)technology can be used as it can enhance the gas and water mobility during dewatering process as a result of capillary pressure change.However,there have been few reported field tests in coal mines using GWA technology.This paper describes a pilot-scale field test in Xinjing coal mine,Yangquan,China.The fluorocarbon surfactants perfluorooctyl methacrylate monomer-containing polymethacrylate(PMP)was used to alter the wettability of coal seam to strong gas-wetness during the hydraulic fracturing process.The study focuses on the comparison of two boreholes(Boreholes#9 and#10)and one other borehole(Borehole#8)with and without using GWA approach.A well-defined monitoring program was established by measuring the dewatering volume of the fracturing fluid and the drainage volume of methane as well as the concentration.The field test results showed that the average methane drainage rates of Boreholes#9(39.28 m^(3)/d)and#10(51.04 m^(3)/d)with GWA treatment exceeded that of Borehole#8(21.09 m^(3)/d)without GWA treatment,with an increase of 86.3%and 142.1%,respectively.The average methane concentrations of Boreholes#9(4.05%)and#10(6.18%)were 64.6%and 151.2%higher than that of Borehole#8(2.46%),respectively.On the other hand,the dewatering ratio of Boreholes#9(4.36%)and#10(3.11%)was almost 19 times and 13 times greater than that of Borehole#8(0.22%).These field test results were in agreement with the experimental data.The significant increase in both methane concentration and dewatering ratio demonstrated that GWA technology could be applied for enhanced methane drainage in coal mines.Important lessons learned at Xinjing coal mine might be applied to other coal mines in China and elsewhere.
基金supported by the Beijing Municipal Science and Technology Project(Grant No.Z201100004220002)the National Natural Science Foundation of China(Grant Nos.61627813,61904009)the China Postdoctoral Science Foundation Funded Project(Grant No.2018M641151)。
文摘Magnetic droplets,a class of highly nonlinear magnetodynamic solitons,can be nucleated and stabilized in nanocontact spintorque nano-oscillators.Here we experimentally demonstrate magnetic droplets in magnetic tunnel junctions(MTJs).The droplet nucleation is accompanied by power enhancement compared with its ferromagnetic resonance modes.The nucleation and stabilization of droplets are ascribed to the double-Co Fe B free-layer structure in the all-perpendicular MTJ,which provides a low Zhang-Li torque and a high pinning field.Our results enable better electrical sensitivity in fundamental studies of droplets and show that the droplets can be utilized in MTJ-based applications and materials science.
文摘The distribution and characteristics of LDH isoenzymes in different tissues of 25spe-cies of vertebrats were comparativety analysed by discontinuous polyacrylamide gel diskelectrophoresis,combined with experiments on heat and urea inhibition.The result showed that indifferent tissues of Cienopharyngodon idellus,Carassius,ayratus,Trichiurus haumete and Miichihysmiiuy in addition to the distribution of LDH isoenzymes,composed of A and B subuits,a E4isoenzyme band,moving very fast to the positive pole,was detectedin the eye tissue of Trichiurushaumele and a F4 isoenzyme hand,moving very slow to the positive pole,was found in liver andkidney of Cienopharyngodon idellus.The A4 isoenzyme band was found in different tisseues ofPleuronichlhys cornulus,inhabiting on the bottom of the ocean.From the amphition to the mammal,with the exception of Hyta arboreu immaculata,Chinnemys reevesii,Trioyx sinensis,Gallus gallusdomeslicus and Corvus macrorhynchos,which have special electrophoretic behaviours.In
