为探究路基黄土的剪切特征,获取Mohr-Coulomb(M-C)模型参数内摩擦角φ和黏聚力c,Ducker-Prager(D-P)模型参数β和d,控制压实度为94%,含水率ω为9.5%、11.5%、13.5%、15.5%、19.5%,利用GDS(Geotechnical digital systems,GDS)静三轴仪在...为探究路基黄土的剪切特征,获取Mohr-Coulomb(M-C)模型参数内摩擦角φ和黏聚力c,Ducker-Prager(D-P)模型参数β和d,控制压实度为94%,含水率ω为9.5%、11.5%、13.5%、15.5%、19.5%,利用GDS(Geotechnical digital systems,GDS)静三轴仪在100、200、300 kPa围压下开展重塑黄土不固结不排水三轴剪切试验,并进行有限元模拟,分析模型在表征黄土剪切特性时的误差。研究结果表明:当ω为9.5%时,100 kPa和200 kPa围压下土样应力应变曲线出现“软化”现象,当ω在11.5%~19.5%之间时,所有围压下土样应力应变均出现“硬化”现象。土的内摩擦角φ和黏聚力c,β和d均随含水率增大而减小,随围压增大而增大;当含水率大于最佳含水率时,黏聚力c和d会迅速减小。有限元模拟对比M-C和D-P模型,发现M-C模型能更好地反映黄土的剪切特性。最终得到了M-C和D-P模型的力学参数,并给出拟合公式,可预测压实度为94%、含水率在9.5%~19.5%范围内土样的模型参数,为工程建设提供参考。展开更多
Raman spectroscopy offers a great power to detect,analyze and identify molecules,and monitor their temporal dynamics and evolution when combined with single-molecule surface-enhanced Raman scattering(SM-SERS)substrate...Raman spectroscopy offers a great power to detect,analyze and identify molecules,and monitor their temporal dynamics and evolution when combined with single-molecule surface-enhanced Raman scattering(SM-SERS)substrates.Here we present a SM-SERS scheme that involves simultaneously giant chemical enhancement from WS22D materials,giant electromagnetic enhancement from plasmonic nanogap hot spot,and inhibition of molecular fluorescence influence under near-infrared laser illumination.Remarkably we find Coulomb attraction between analyte and gold nanoparticle can trigger spontaneous formation of molecule-hotspot pairing with high precision,stability and robustness.The scheme has enabled realization of universal,robust,fast,and large-scale uniform SM-SERS detection for three Raman molecules of rhodamine B,rhodamine 6G,and crystal violet with a very low detection limit of 10−16 M and at a very fast spectrum acquisition time of 50 ms.展开更多
This study theoretically investigates chaos in a cavity optomechanical system with Coulomb coupling.The system consists of a Fabry-Pérot cavity with a movable mirror,where Coulomb interactions arise from charging...This study theoretically investigates chaos in a cavity optomechanical system with Coulomb coupling.The system consists of a Fabry-Pérot cavity with a movable mirror,where Coulomb interactions arise from charging the two movable mirrors.We examine the chaotic dynamics under the influence of both single and bichromatic laser fields.The single laser field represents a system driven exclusively by the pump field,whereas the bichromatic field represents simultaneous driving by both the pump and probe fields.In addition to conventional chaos-inducing methods through parameter variations,we demonstrate that increasing the Coulomb coupling strength enhances the system’s nonlinearity and induces chaotic behavior.Furthermore,we propose several strategies for generating and controlling chaos,while also identifying the parameter ranges necessary for the resonance of the two mechanical oscillators.Interestingly,when adjusting the driving power in a system driven solely by the pump field,we unexpectedly observe the emergence of high-order sidebands.These findings contribute to the development of chaotic behavior in future cavity optomechanical systems and provide a theoretical basis for applications in physical random number generation and secure communication.展开更多
Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batt...Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.展开更多
This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the atto...This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.展开更多
C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initia...C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initial Coulombic efficiency(ICE),which significantly hinders its practical application.Herein,we reported a straightforward iodine redox chemistry strategy to realize highly reversible Li storage behavior and remarkably enhanced ICE of high-capacity C/SiO_(x)anode toward long-life lithium-ion batteries.Specifically,I2is introduced into porous C/SiO_(x)via simple fumigation to synthesize their composite(C/SiO_(x)@I),in which I_(2)can effectively inhibit the irreversible lithiation reactions of SiO_(x)through redox reaction.Further,redox reaction intermediates of LiI_(3)and LiIO_(3)can inhibit the decomposition of electrolyte and LiPF6,thereby reducing the thickness of the solid-electrolyte interphase film.Consequently,the obtained C/SiO_(x)@I exhibits a considerable capacity of 1241 mAh g^(-1)with an improved ICE of 88.5%at 0.1 A g^(-1)and impressive cyclability,showing capacity retention of 95%after 700 cycles at5.0 A g^(-1).Besides,the C/SiO_(x)@I with a 12%addition ratio can greatly enhance the capacity of graphite from 352 to 454 mAh g^(-1),with negligible impact on its ICE.When the addition ratio is 9%,the energy density of the 18,650 cylindrical battery composed of graphite and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)can be enhanced by approximately 25 Wh kg^(-1).This study opens a new avenue for developing high ICE in SiO_(x)-based anodes for high-energy-density lithium-ion batteries.展开更多
Two long-term slow slip events(SSEs) in Lower Cook Inlet, Alaska, were identified by Li SS et al.(2016). The earlier SSE lasted at least 9 years with M_(w) ~7.8 and had an average slip rate of ~82 mm/year. The latter ...Two long-term slow slip events(SSEs) in Lower Cook Inlet, Alaska, were identified by Li SS et al.(2016). The earlier SSE lasted at least 9 years with M_(w) ~7.8 and had an average slip rate of ~82 mm/year. The latter SSE, occurring in a similar area, lasted approximately 2 years with M_(w) ~7.2 and an average slip rate of ~91 mm/year. To test whether these SSEs triggered earthquakes near the slow slip area, we calculated the Coulomb stressing rate changes on receiver faults by using two fault geometry definitions: nodal planes of focal mechanism solutions of past earthquakes, and optimally oriented fault planes. Regions in the shallow slab(30–60 km) that experienced a significant increase in the Coulomb stressing rate due to slip by the SSEs showed an increase in seismicity rates during SSE periods. No correlation was found in the volumes that underwent a significant increase in the Coulomb stressing rate during the SSE within the crust and the intermediate slab. We modeled variations in seismicity rates by using a combination of the Coulomb stress transfer model and the framework of rate-and-state friction. Our model indicated that the SSEs increased the Coulomb stress changes on adjacent faults,thereby increasing the seismicity rates even though the ratio of the SSE stressing rate to the background stressing rate was small. Each long-term SSE in Alaska brought the megathrust updip of the SSE areas closer to failure by up to 0.1–0.15 MPa. The volumes of significant Coulomb stress changes caused by the Upper and Lower Cook Inlet SSEs did not overlap.展开更多
In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-bindi...In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.展开更多
[目的]地下硐室施工涉及复杂的地质条件,如软弱围岩、破碎带和断层等。这些区域的围岩稳定性较差,容易发生塌方、滑移等地质灾害。因此,研究硐室围岩的稳定性对于理论研究与工程实践均具有重要意义。文章旨在探讨Mohr-Coulomb强度准则与...[目的]地下硐室施工涉及复杂的地质条件,如软弱围岩、破碎带和断层等。这些区域的围岩稳定性较差,容易发生塌方、滑移等地质灾害。因此,研究硐室围岩的稳定性对于理论研究与工程实践均具有重要意义。文章旨在探讨Mohr-Coulomb强度准则与Hoek-Brown强度准则对压缩空气储能(Compressed Air Energy Storage,CAES)地下硐室施工的影响,比较不同强度准则下硐室稳定性的差异及其在设计中的适用性。[方法]基于FLAC3D数值模拟方法,以内蒙古某CAES电站密封硐库地下工程为背景,采用了Mohr-Coulomb和Hoek-Brown两种强度准则,分析了硐室围岩承压状态下的位移变形和塑性区分布情况。通过模拟计算,比较了不同强度准则对围岩变形及塑性区影响的差异,进一步评估了大罐式硐室、圆截面隧道和马蹄形隧道3种硐室形式的性能。[结果]模拟结果表明,采用Mohr-Coulomb与Hoek-Brown强度准则得到的硐室稳定性分析结果基本一致。大罐式硐室在应力分布和塑性区控制方面表现更优,显示出更好的稳定性与安全性。相比之下,圆截面隧道和马蹄形隧道的稳定性较差,特别是在高压储气条件下。[结论]文章为地下硐室在高压储气条件下的优化设计与施工提供了重要参考,验证了大罐式硐室在控制围岩变形、降低塑性破坏风险方面的优势,具有良好的应用前景。研究成果为CAES项目中地下硐室设计提供了理论依据,并为实际工程实践提供了指导。展开更多
基金financial support from Science and Technology Project of Guangdong(2020B010190001)National Natural Science Foundation(12434016).
文摘Raman spectroscopy offers a great power to detect,analyze and identify molecules,and monitor their temporal dynamics and evolution when combined with single-molecule surface-enhanced Raman scattering(SM-SERS)substrates.Here we present a SM-SERS scheme that involves simultaneously giant chemical enhancement from WS22D materials,giant electromagnetic enhancement from plasmonic nanogap hot spot,and inhibition of molecular fluorescence influence under near-infrared laser illumination.Remarkably we find Coulomb attraction between analyte and gold nanoparticle can trigger spontaneous formation of molecule-hotspot pairing with high precision,stability and robustness.The scheme has enabled realization of universal,robust,fast,and large-scale uniform SM-SERS detection for three Raman molecules of rhodamine B,rhodamine 6G,and crystal violet with a very low detection limit of 10−16 M and at a very fast spectrum acquisition time of 50 ms.
基金supported by Young Talents from Longyuan,Gansu Province(Liwei Liu),the Fundamental Research Funds for the Central Universities,Northwest Minzu University(Grant No.31920230134)Teaching Achievement Cultivation Project of Gansu Province Department of Education(Grant No.2022GSJXCGPY-46)+1 种基金Special research topic on curriculum and teaching materials for primary,secondary and higher schools,Gansu Province Department of Education(Grant No.GSJC-Y2024204)Quality improvement project for undergraduate talent training,Northwest Minzu University(Grant Nos.2024YBJG-04 and 2024FCTD-03).
文摘This study theoretically investigates chaos in a cavity optomechanical system with Coulomb coupling.The system consists of a Fabry-Pérot cavity with a movable mirror,where Coulomb interactions arise from charging the two movable mirrors.We examine the chaotic dynamics under the influence of both single and bichromatic laser fields.The single laser field represents a system driven exclusively by the pump field,whereas the bichromatic field represents simultaneous driving by both the pump and probe fields.In addition to conventional chaos-inducing methods through parameter variations,we demonstrate that increasing the Coulomb coupling strength enhances the system’s nonlinearity and induces chaotic behavior.Furthermore,we propose several strategies for generating and controlling chaos,while also identifying the parameter ranges necessary for the resonance of the two mechanical oscillators.Interestingly,when adjusting the driving power in a system driven solely by the pump field,we unexpectedly observe the emergence of high-order sidebands.These findings contribute to the development of chaotic behavior in future cavity optomechanical systems and provide a theoretical basis for applications in physical random number generation and secure communication.
基金supported by the faculty research fund of Sejong Universityfunding from the National Research Foundation of Korea(NRF)under grant number NRF-2022R1F1A1071444+2 种基金funding from NRF under grant numbers NRF-2022R1A2B5B03001781Funding provided by the Department of Energy Office of Energy EfficiencyRenewable Energy Vehicles Technology Office。
文摘Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the wo rld.In general,it is thought that the electrochemical performance of recha rgeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role.However,ion transport and storage can be greatly influenced by the electrolyte solution structure,specifically,ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces.Herein,we studied the role of the electrolyte as an active component of electrochemical energy storage devices.We found that with an appropriate electrolyte formulation,ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy.Reduced graphene oxide(RGO)in an ether-based electrolyte demonstrates'spontaneous'ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO,which results in Coulombic efficiency of~145%due to additional charging capacity of~180 mAh g^(-1)during electrochemical processes.The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics,advanced characterizations,and computational simulation.We believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174239,12347165,and 12404330)Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.23JSY022)+2 种基金Natural Science Basic Research Program of Shaanxi(Grant No.2022JM-015)Hebei Natural Science Foundation(Grant No.A2022205002)Science and Technology Project of Hebei Education Department(Grant No.QN2022143)。
文摘This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.
基金financially supported by the National Natural Science Foundation of China(No.51962027,and 52262039)the Major Science and Technology Project of Inner Mongolia Autonomous Region(2021ZD0016)+3 种基金the National Key R&D Program of China(2020YFC1909105)the Fundamental Research Funds for Inner Mongolia University of Science&Technology(NO.2024QNJS071,2023QNJS052 and 2024QNJS064)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT24002)the Central Guidance Fund for Local Scientific and Technological Development(2024ZY0012)。
文摘C/SiO_(x)anode with higher capacity and lower lithiation potential has been recognized as a nextgeneration alternative to graphite for high-energy-density lithium-ion batteries.However,C/SiO_(x)suffers from low initial Coulombic efficiency(ICE),which significantly hinders its practical application.Herein,we reported a straightforward iodine redox chemistry strategy to realize highly reversible Li storage behavior and remarkably enhanced ICE of high-capacity C/SiO_(x)anode toward long-life lithium-ion batteries.Specifically,I2is introduced into porous C/SiO_(x)via simple fumigation to synthesize their composite(C/SiO_(x)@I),in which I_(2)can effectively inhibit the irreversible lithiation reactions of SiO_(x)through redox reaction.Further,redox reaction intermediates of LiI_(3)and LiIO_(3)can inhibit the decomposition of electrolyte and LiPF6,thereby reducing the thickness of the solid-electrolyte interphase film.Consequently,the obtained C/SiO_(x)@I exhibits a considerable capacity of 1241 mAh g^(-1)with an improved ICE of 88.5%at 0.1 A g^(-1)and impressive cyclability,showing capacity retention of 95%after 700 cycles at5.0 A g^(-1).Besides,the C/SiO_(x)@I with a 12%addition ratio can greatly enhance the capacity of graphite from 352 to 454 mAh g^(-1),with negligible impact on its ICE.When the addition ratio is 9%,the energy density of the 18,650 cylindrical battery composed of graphite and Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)can be enhanced by approximately 25 Wh kg^(-1).This study opens a new avenue for developing high ICE in SiO_(x)-based anodes for high-energy-density lithium-ion batteries.
基金supported by the National Natural Science Foundation of China (Grant No. 42104001)。
文摘Two long-term slow slip events(SSEs) in Lower Cook Inlet, Alaska, were identified by Li SS et al.(2016). The earlier SSE lasted at least 9 years with M_(w) ~7.8 and had an average slip rate of ~82 mm/year. The latter SSE, occurring in a similar area, lasted approximately 2 years with M_(w) ~7.2 and an average slip rate of ~91 mm/year. To test whether these SSEs triggered earthquakes near the slow slip area, we calculated the Coulomb stressing rate changes on receiver faults by using two fault geometry definitions: nodal planes of focal mechanism solutions of past earthquakes, and optimally oriented fault planes. Regions in the shallow slab(30–60 km) that experienced a significant increase in the Coulomb stressing rate due to slip by the SSEs showed an increase in seismicity rates during SSE periods. No correlation was found in the volumes that underwent a significant increase in the Coulomb stressing rate during the SSE within the crust and the intermediate slab. We modeled variations in seismicity rates by using a combination of the Coulomb stress transfer model and the framework of rate-and-state friction. Our model indicated that the SSEs increased the Coulomb stress changes on adjacent faults,thereby increasing the seismicity rates even though the ratio of the SSE stressing rate to the background stressing rate was small. Each long-term SSE in Alaska brought the megathrust updip of the SSE areas closer to failure by up to 0.1–0.15 MPa. The volumes of significant Coulomb stress changes caused by the Upper and Lower Cook Inlet SSEs did not overlap.
基金was supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611200 and 2018YFA0307000)the National Natural Science Foundation of China(Grant Nos.12274154 and 12404182)。
文摘In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.
文摘[目的]地下硐室施工涉及复杂的地质条件,如软弱围岩、破碎带和断层等。这些区域的围岩稳定性较差,容易发生塌方、滑移等地质灾害。因此,研究硐室围岩的稳定性对于理论研究与工程实践均具有重要意义。文章旨在探讨Mohr-Coulomb强度准则与Hoek-Brown强度准则对压缩空气储能(Compressed Air Energy Storage,CAES)地下硐室施工的影响,比较不同强度准则下硐室稳定性的差异及其在设计中的适用性。[方法]基于FLAC3D数值模拟方法,以内蒙古某CAES电站密封硐库地下工程为背景,采用了Mohr-Coulomb和Hoek-Brown两种强度准则,分析了硐室围岩承压状态下的位移变形和塑性区分布情况。通过模拟计算,比较了不同强度准则对围岩变形及塑性区影响的差异,进一步评估了大罐式硐室、圆截面隧道和马蹄形隧道3种硐室形式的性能。[结果]模拟结果表明,采用Mohr-Coulomb与Hoek-Brown强度准则得到的硐室稳定性分析结果基本一致。大罐式硐室在应力分布和塑性区控制方面表现更优,显示出更好的稳定性与安全性。相比之下,圆截面隧道和马蹄形隧道的稳定性较差,特别是在高压储气条件下。[结论]文章为地下硐室在高压储气条件下的优化设计与施工提供了重要参考,验证了大罐式硐室在控制围岩变形、降低塑性破坏风险方面的优势,具有良好的应用前景。研究成果为CAES项目中地下硐室设计提供了理论依据,并为实际工程实践提供了指导。
