We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonometh...We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.展开更多
Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemi...Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).展开更多
Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. Accordin...Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. According to Kepler’s 1st Law, “orbit of a planet with respect to the Sun is an ellipse, with the Sun at one of the two foci.” Orbit of the Moon with respect to Earth is also distinctly elliptical, but this ellipse has a varying eccentricity as the Moon comes closer to and goes farther away from the Earth in a harmonic style along a full cycle of this ellipse. In this paper, our research results are summarized, where it is first mathematically shown that the “distance between points around any two different circles in three-dimensional space” is equivalent to the “distance of points around a vector ellipse to another fixed or moving point, as in two-dimensional space”. What is done is equivalent to showing that bodies moving on two different circular orbits in space vector-wise behave as if moving on an elliptical path with respect to each other, and virtually seeing each other as positioned at an instantaneously stationary point in space on their relative ecliptic plane, whether they are moving with the same angular velocity, or different but fixed angular velocities, or even with different and changing angular velocities with respect to their own centers of revolution. This mathematical revelation has the potential to lead to far reaching discoveries in physics, enabling more insight into forces of nature, with a formulation of a new fundamental model regarding the motions of bodies in the Universe, including the Sun, Planets, and Satellites in the Solar System and elsewhere, as well as at particle and subatomic level. Based on the demonstrated mathematical analysis, as they exhibit almost fixed elliptic orbits relative to one another over time, the assertion is made that the Sun, the Earth, and the Moon must each be revolving in their individual circular orbits of revolution in space. With this expectation, individual orbital parameters of the Sun, the Earth, and the Moon are calculated based on observed Earth to Sun and Earth to Moon distance data, also using analytical methods developed as part of this research to an approximation. This calculation and analysis process have revealed additional results aligned with observation, and this also supports our assertion that the Sun, the Earth, and the Moon must actually be revolving in individual circular orbits.展开更多
Multi-electron and multi-orbital effects play a crucial role in the interaction of strong laser fields with complex molecules.Here,multi-electron effects encompass not only electron-electron Coulomb interactions and e...Multi-electron and multi-orbital effects play a crucial role in the interaction of strong laser fields with complex molecules.Here,multi-electron effects encompass not only electron-electron Coulomb interactions and exchangecorrelation effects but also the interference between the dynamics of different electron wave packets.展开更多
The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contribu...The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.展开更多
Dear Editor,Traumatic optic neuropathy(TON)is a severe vision-threatening condition,with an incidence rate ranging from 0.7% to 2.5%[1].The limited regenerative capacity of the optic nerve and the challenges of nerve ...Dear Editor,Traumatic optic neuropathy(TON)is a severe vision-threatening condition,with an incidence rate ranging from 0.7% to 2.5%[1].The limited regenerative capacity of the optic nerve and the challenges of nerve transplantation result in substantial and irreversible visual loss in patients with TON.展开更多
After a few days,there will be a“gazelle company”jumping f rom the Government Work Repor t of the National People’s Congress and Chinese People’s Political Consultative Conference to China International Supply Cha...After a few days,there will be a“gazelle company”jumping f rom the Government Work Repor t of the National People’s Congress and Chinese People’s Political Consultative Conference to China International Supply Chain Expo(CISCE).Tianjin Yunyao Aerospace Tech nolog y Co.,Ltd(hereinafter referred to as Yunyao Aerospace)is a young enterprise founded in March 2019.It has already obtained impressive achievements in the commercial aerospace field.展开更多
The development of magnetic heterostructures with strong perpendicular magnetic anisotropy(PMA),strong spin-orbit torques(SOTs),low impedance,and good integration compatibility at the same time is central for high-per...The development of magnetic heterostructures with strong perpendicular magnetic anisotropy(PMA),strong spin-orbit torques(SOTs),low impedance,and good integration compatibility at the same time is central for high-performance spintronic memory and computing applications.Here,we report the development of the PMA superlattice[Pt/Co/W]_(n)that can be sputtered-deposited on commercial oxidized silicon substrates and has giant SOTs,strong uniaxial PMA of≈9.2 Merg/cm^(3),and rigid macrospin performance.The damping-like and field-like SOTs of the[Pt/Co/W]_(n)superlattices exhibit a linear increase with the repeat number n and reach the giant values of 225%and-33%(two orders of magnitude greater than that in clean-limit Pt)at n=12,respectively.The damping-like SOT is also of the opposite sign and much greater in magnitude than the field-like SOT,regardless of the number n.These results clarify that the spin current that generates SOTs in the[Pt/Co/W]_(n)superlattices arises predominantly from the spin Hall effect rather than bulk Rashba spin splitting,providing a unified understanding of the SOTs in these superlattices.We also demonstrate deterministic switching in thickerthan-50-nm PMA[Pt/Co/W]_(12)superlattices at a low current density.This work establishes the[Pt/Co/W]_(n)superlattice as a compelling material candidate for ultra-fast,low-power,long-retention nonvolatile spintronic memory and computing technologies.展开更多
AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy...AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy(GPT).METHODS:A total of 57 eligible patients(35.09%males,mean age of 51.19±11.90y)were included in this case-series study.The medical information collected during each visit was evaluated and analyzed.RESULTS:Significant improvement was observed in patients six months after radiation therapy.Both the clinical activity score and the efficacy score showed substantial improvement(P<0.001).Furthermore,there was significant resolution of extraocular muscle inflammation on magnetic resonance imaging at three and six months after radiation therapy.The initial high signal intensity ratio(SIR)max was found to be associated with greater improvement in SIR sum(P<0.001,B=2.002,95%CI:1.377 to 2.628),while the presence of sight-threatening stage or moderate to severe diplopia negatively influenced the improvement of SIR sum(P=0.045,0.008,0.006;B=-1.966,-1.478,-0.997;95%CI:-3.886 to-0.045,-2.552 to-0.403,-1.694 to-0.300;respectively).CONCLUSION:The combination therapy demonstrates significant effectiveness in treating patients with GO who experienced severe ocular inflammation and have previous GPT failure.Noticeable improvement is observed as early as one month after initiating radiation therapy,and patients with more severe inflammatory states showes greater benefit from the treatment.展开更多
Taking the GY8HC well in the Gulong Sag of the Songliao Basin,NE China,as an example,this study utilized high-precision zircon U-Pb ages from volcanic ashes and AstroBayes method to estimate sedimentation rates.Throug...Taking the GY8HC well in the Gulong Sag of the Songliao Basin,NE China,as an example,this study utilized high-precision zircon U-Pb ages from volcanic ashes and AstroBayes method to estimate sedimentation rates.Through spectral analysis of high-resolution total organic carbon content(TOC),laboratory-measured free hydrocarbons(S_(1)),hydrocarbons formed during pyrolysis(S_(2)),and mineral contents,the enrichment characteristics and controlling factors of shale oil in an overmature area were investigated.The results indicate that:(1)TOC,S_(1),and S_(2)associated with shale oil enrichment exhibit a significant 173×10^(3)a obliquity amplitude modulation cycle;(2)Quartz and illite/smectite mixed-layer contents related to lithological composition show a significant 405×10^(3)a long eccentricity cycle;(3)Comparative studies with the high-maturity GY3HC well and moderate-maturity ZY1 well reveal distinct in-situ enrichment characteristics of shale oil in the overmature Qingshankou Formation,with a significant positive correlation to TOC,indicating that high TOC is a key factor for shale oil enrichment in overmature areas;(4)The sedimentary thickness of 12-13 m corresponding to the 173×10^(3)a cycle can serve as the sweet spot interval height for shale oil development in the study area,falling within the optimal fracture height range(10-15 m)generated during hydraulic fracturing of the Qingshankou shale.Orbitally forced climate changes not only controlled the sedimentary rhythms of organic carbon burial and lithological composition in the Songliao Basin but also influenced the enrichment characteristics and sweet spot distribution of Gulong shale oil.展开更多
This paper focuses on propagating perturbed two-body motion using orbital elements combined with a novel integration technique.While previous studies show that Modified Chebyshev Picard Iteration(MCPI)is a powerful to...This paper focuses on propagating perturbed two-body motion using orbital elements combined with a novel integration technique.While previous studies show that Modified Chebyshev Picard Iteration(MCPI)is a powerful tool used to propagate position and velocity,the present results show that using orbital elements to propagate the state vector reduces the number of MCPI iterations and nodes required,which is especially useful for reducing the computation time when including computationally-intensive calculations such as Spherical Harmonic gravity,and it also converges for>5.5x as many revolutions using a single segment when compared with cartesian propagation.Results for the Classical Orbital Elements and the Modified Equinoctial Orbital Elements(the latter provides singularity-free solutions)show that state propagation using these variables is inherently well-suited to the propagation method chosen.Additional benefits are achieved using a segmentation scheme,while future expansion to the two-point boundary value problem is expected to increase the domain of convergence compared with the cartesian case.MCPI is an iterative numerical method used to solve linear and nonlinear,ordinary differential equations(ODEs).It is a fusion of orthogonal Chebyshev function approximation with Picard iteration that approximates a long-arc trajectory at every iteration.Previous studies have shown that it outperforms the state of the practice numerical integrators of ODEs in a serial computing environment;since MCPI is inherently massively parallelizable,this capability is expected to increase the computational efficiency of the method presented.展开更多
Lithium-sulfur(Li-S)batteries are considered a potential candidate for next-generation energy-dense and sustainable energy storage.However,the slow conversion and severe shuttle of polysulfides(LiPSs)result in rapid p...Lithium-sulfur(Li-S)batteries are considered a potential candidate for next-generation energy-dense and sustainable energy storage.However,the slow conversion and severe shuttle of polysulfides(LiPSs)result in rapid performance degradation over long-term cycling.Herein,we report a high-entropy single-atom(HE-SA)catalyst to regulate the multi-step conversion of LiPS to attain a high-performance Li-S battery.Both the density functional theory calculations and the experimental results prove that the Fe atomic site with high spin configurations strongly interacts with Li_(2)S_(4)through d-p and s-p synergistic orbital hybridization which facilitates the reduction of LiPS.Moreover,S-dominant p-d hybridization between Li_(2)S and a high-spin Mn site weakens the Li-S bond and facilitates the rapid sulfur evolution reaction.Consequently,the Li-S battery with a bifunctional HE-SA catalyst shows an ultralow capacity decay of 0.026% per cycle over 1900 cycles at 1 C.This work proposes a high-entropy strategy for sculpting electronic structures to enable spin and orbital hybridization modulation in advanced catalysts toward longcycling Li-S batteries.展开更多
In February 2025,a startup satellite manufacturer,Albedo(Broomfield,CO,USA)is expected to launch its first satellite,Clarity-1,into orbit aboard SpaceX’s Transporter-13,a Falcon 9 rideshare mission[1].Like many imagi...In February 2025,a startup satellite manufacturer,Albedo(Broomfield,CO,USA)is expected to launch its first satellite,Clarity-1,into orbit aboard SpaceX’s Transporter-13,a Falcon 9 rideshare mission[1].Like many imaging satellites,Clarity-1’s mis-sion will be to take high-resolution aerial photos for clients in var-ious economic sectors including agriculture,insurance,energy,mapping,utilities,and defense.What makes this satellite unique is both its industry-leading 10 cm spatial resolution and its extre-mely low orbit of 200 km,far closer to Earth than the 450 km or higher orbits of most of its peers with similar missions.展开更多
The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin proje...The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin project delineates detailed requirements for orbit determination during both the launch phase and subsequent scientific experimentation.This paper pioneers the investigation of Precise Orbit Determination(POD)for Tian Qin utilizing the third generation of Bei Dou global navigation satellite system(BDS-3)Inter-Satellite Link(ISL)through simulation.By analyzing the visibility,the feasibility of using BDS-3 ISLs for Tian Qin POD is explored.Furthermore,a refined Solar Radiation Pressure(SRP)model is developed,and the POD accuracy of Tian Qin is assessed,considering factors such as arc length,ranging intervals,and error sources.The results indicate the following:(A)Visibility between Tian Qin and BDS-3 satellites is intermittent,with an average of 10.6 BDS-3 satellites visible to Tian Qin,and the average Root Mean Square(RMS)-value of Position Dilution of Precision(PDOP)for Tian Qin is 48.13.(B)POD accuracy improves with shorter ranging intervals.(C)The error in ephemeris is the dominant factor affecting the POD accuracy.(D)The establishment of three links between Tian Qin and the BDS-3 satellites satisfies the POD requirements of Tian Qin.With a ranging interval of 600 s and over a 7-day arc,the average three-Dimensional(3D)position accuracy of the three Tian Qin satellites is 1.35 m,while the 3D velocity accuracy is 0.08 mm/s.展开更多
AIM: To investigate the diffusion changes in both the optic nerve and optic tract in orbital space-occupying lesion patients with decreased visual acuity, and its clinical significance using probabilistic diffusion tr...AIM: To investigate the diffusion changes in both the optic nerve and optic tract in orbital space-occupying lesion patients with decreased visual acuity, and its clinical significance using probabilistic diffusion tractography(PDT). METHODS: Twenty patients with orbital space-occupying lesions and 25 age-and gender-matched healthy persons were included. All patients and controls underwent routine orbital magnetic resonance imaging and diffusion tensor imaging(DTI), using a 3.0 T magnetic resonance scanner(Trio Tim Siemens). After the image data were preprocessed, each DTI parameters of the optic nerve and optic tract was obtained by PDT, including fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD) and radial diffusivity(RD). The asymmetry index(AI) of each parameter was calculated. Compared the parameters of the affected side optic nerve and ipsilateral optic tract with the contralateral side by paired sample t-test;compared AI of parameters of optic nerve and optic tract between the patient group and the control group by independent sample t-test. Patients were divided into threesubgroups according to the low vision grade standard of WHO, compared the FA and AI of FA between the three subgroups by single factor variance analysis. RESULTS: The affected side optic nerve presented significantly decreased FA, increased MD, AD, and RD values compared to the unaffected side(P<0.05). The AI of FA, MD, AD, and RD of optic nerve in the patients was significantly higher than that of the controls(P<0.05). The comparison results of the optic tract showed that there was no significant difference between the patient group and control group in terms of the bilateral optic tracts in patients(P>0.05). The AIs of the FA value of the optic nerve in the eyesight <0.1 subgroup was significantly higher than that in the other groups(P<0.05). CONCLUSION: FA, MD, AD, and RD of the affected side optic nerve of the orbital space-occupying lesions have significantly changed, the FA value is the most sensitive. The PDT could be a useful tool to provide valid quantitative markers of optic nerve injuries and evaluate the severity of orbital diseases, which other examinations cannot be acquired.展开更多
This paper proposes an optimal,robust,and efficient guidance scheme for the perturbed minimum-time low-thrust transfer toward the geostationary orbit.The Earth’s oblateness perturbation and shadow are taken into acco...This paper proposes an optimal,robust,and efficient guidance scheme for the perturbed minimum-time low-thrust transfer toward the geostationary orbit.The Earth’s oblateness perturbation and shadow are taken into account.It is difficult for a Lyapunov-based or trajectory-tracking guidance method to possess multiple characteristics at the same time,including high guidance optimality,robustness,and onboard computational efficiency.In this work,a concise relationship between the minimum-time transfer problem with orbital averaging and its optimal solution is identified,which reveals that the five averaged initial costates that dominate the optimal thrust direction can be approximately determined by only four initial modified equinoctial orbit elements after a coordinate transformation.Based on this relationship,the optimal averaged trajectories constituting the training dataset are randomly generated around a nominal averaged trajectory.Five polynomial regression models are trained on the training dataset and are regarded as the costate estimators.In the transfer,the spacecraft can obtain the real-time approximate optimal thrust direction by combining the costate estimations provided by the estimators with the current state at any time.Moreover,all these computations onboard are analytical.The simulation results show that the proposed guidance scheme possesses extremely high guidance optimality,robustness,and onboard computational efficiency.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.
文摘Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).
文摘Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. According to Kepler’s 1st Law, “orbit of a planet with respect to the Sun is an ellipse, with the Sun at one of the two foci.” Orbit of the Moon with respect to Earth is also distinctly elliptical, but this ellipse has a varying eccentricity as the Moon comes closer to and goes farther away from the Earth in a harmonic style along a full cycle of this ellipse. In this paper, our research results are summarized, where it is first mathematically shown that the “distance between points around any two different circles in three-dimensional space” is equivalent to the “distance of points around a vector ellipse to another fixed or moving point, as in two-dimensional space”. What is done is equivalent to showing that bodies moving on two different circular orbits in space vector-wise behave as if moving on an elliptical path with respect to each other, and virtually seeing each other as positioned at an instantaneously stationary point in space on their relative ecliptic plane, whether they are moving with the same angular velocity, or different but fixed angular velocities, or even with different and changing angular velocities with respect to their own centers of revolution. This mathematical revelation has the potential to lead to far reaching discoveries in physics, enabling more insight into forces of nature, with a formulation of a new fundamental model regarding the motions of bodies in the Universe, including the Sun, Planets, and Satellites in the Solar System and elsewhere, as well as at particle and subatomic level. Based on the demonstrated mathematical analysis, as they exhibit almost fixed elliptic orbits relative to one another over time, the assertion is made that the Sun, the Earth, and the Moon must each be revolving in their individual circular orbits of revolution in space. With this expectation, individual orbital parameters of the Sun, the Earth, and the Moon are calculated based on observed Earth to Sun and Earth to Moon distance data, also using analytical methods developed as part of this research to an approximation. This calculation and analysis process have revealed additional results aligned with observation, and this also supports our assertion that the Sun, the Earth, and the Moon must actually be revolving in individual circular orbits.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0134200)the National Natural Science Foundation of China(Grant No.12204214)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.GK202207012)QCYRCXM-2022-241。
文摘Multi-electron and multi-orbital effects play a crucial role in the interaction of strong laser fields with complex molecules.Here,multi-electron effects encompass not only electron-electron Coulomb interactions and exchangecorrelation effects but also the interference between the dynamics of different electron wave packets.
基金financially supported by the Science Center of the National Science Foundation of China (Grant No. 52088101)the National Natural Science Foundation of China (Grant Nos. 52161160334, 12274437, 12174426, and 52271237)+1 种基金the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research No. YSBR-084the CAS Youth Interdisciplinary Team。
文摘The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.
基金supported by Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology(20200730009)the National Natural Science Foundation of China(81870656)the Natural Science Foundation of Guangdong Province of China(2017A030313610 and 2023A1515012397).
文摘Dear Editor,Traumatic optic neuropathy(TON)is a severe vision-threatening condition,with an incidence rate ranging from 0.7% to 2.5%[1].The limited regenerative capacity of the optic nerve and the challenges of nerve transplantation result in substantial and irreversible visual loss in patients with TON.
文摘After a few days,there will be a“gazelle company”jumping f rom the Government Work Repor t of the National People’s Congress and Chinese People’s Political Consultative Conference to China International Supply Chain Expo(CISCE).Tianjin Yunyao Aerospace Tech nolog y Co.,Ltd(hereinafter referred to as Yunyao Aerospace)is a young enterprise founded in March 2019.It has already obtained impressive achievements in the commercial aerospace field.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1204000)the Beijing National Natural Science Foundation(Grant No.Z230006)the National Natural Science Foundation of China(Grant Nos.12304155 and 12274405).
文摘The development of magnetic heterostructures with strong perpendicular magnetic anisotropy(PMA),strong spin-orbit torques(SOTs),low impedance,and good integration compatibility at the same time is central for high-performance spintronic memory and computing applications.Here,we report the development of the PMA superlattice[Pt/Co/W]_(n)that can be sputtered-deposited on commercial oxidized silicon substrates and has giant SOTs,strong uniaxial PMA of≈9.2 Merg/cm^(3),and rigid macrospin performance.The damping-like and field-like SOTs of the[Pt/Co/W]_(n)superlattices exhibit a linear increase with the repeat number n and reach the giant values of 225%and-33%(two orders of magnitude greater than that in clean-limit Pt)at n=12,respectively.The damping-like SOT is also of the opposite sign and much greater in magnitude than the field-like SOT,regardless of the number n.These results clarify that the spin current that generates SOTs in the[Pt/Co/W]_(n)superlattices arises predominantly from the spin Hall effect rather than bulk Rashba spin splitting,providing a unified understanding of the SOTs in these superlattices.We also demonstrate deterministic switching in thickerthan-50-nm PMA[Pt/Co/W]_(12)superlattices at a low current density.This work establishes the[Pt/Co/W]_(n)superlattice as a compelling material candidate for ultra-fast,low-power,long-retention nonvolatile spintronic memory and computing technologies.
基金Supported by the Sichuan Department of Science and Technology(No.2022JDKP0010).
文摘AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy(GPT).METHODS:A total of 57 eligible patients(35.09%males,mean age of 51.19±11.90y)were included in this case-series study.The medical information collected during each visit was evaluated and analyzed.RESULTS:Significant improvement was observed in patients six months after radiation therapy.Both the clinical activity score and the efficacy score showed substantial improvement(P<0.001).Furthermore,there was significant resolution of extraocular muscle inflammation on magnetic resonance imaging at three and six months after radiation therapy.The initial high signal intensity ratio(SIR)max was found to be associated with greater improvement in SIR sum(P<0.001,B=2.002,95%CI:1.377 to 2.628),while the presence of sight-threatening stage or moderate to severe diplopia negatively influenced the improvement of SIR sum(P=0.045,0.008,0.006;B=-1.966,-1.478,-0.997;95%CI:-3.886 to-0.045,-2.552 to-0.403,-1.694 to-0.300;respectively).CONCLUSION:The combination therapy demonstrates significant effectiveness in treating patients with GO who experienced severe ocular inflammation and have previous GPT failure.Noticeable improvement is observed as early as one month after initiating radiation therapy,and patients with more severe inflammatory states showes greater benefit from the treatment.
基金Supported by the National Natural Science Foundation of China(42372162,4244205C)Project of"Solving Problems by Listing Talents"in Heilongjiang Province(2022-JS-1740,2022-JS-1853)Project on the Theory of Oil and Gas Enrichment from the Interaction of Earth's Multiple Spheres(THEMSIE04010103).
文摘Taking the GY8HC well in the Gulong Sag of the Songliao Basin,NE China,as an example,this study utilized high-precision zircon U-Pb ages from volcanic ashes and AstroBayes method to estimate sedimentation rates.Through spectral analysis of high-resolution total organic carbon content(TOC),laboratory-measured free hydrocarbons(S_(1)),hydrocarbons formed during pyrolysis(S_(2)),and mineral contents,the enrichment characteristics and controlling factors of shale oil in an overmature area were investigated.The results indicate that:(1)TOC,S_(1),and S_(2)associated with shale oil enrichment exhibit a significant 173×10^(3)a obliquity amplitude modulation cycle;(2)Quartz and illite/smectite mixed-layer contents related to lithological composition show a significant 405×10^(3)a long eccentricity cycle;(3)Comparative studies with the high-maturity GY3HC well and moderate-maturity ZY1 well reveal distinct in-situ enrichment characteristics of shale oil in the overmature Qingshankou Formation,with a significant positive correlation to TOC,indicating that high TOC is a key factor for shale oil enrichment in overmature areas;(4)The sedimentary thickness of 12-13 m corresponding to the 173×10^(3)a cycle can serve as the sweet spot interval height for shale oil development in the study area,falling within the optimal fracture height range(10-15 m)generated during hydraulic fracturing of the Qingshankou shale.Orbitally forced climate changes not only controlled the sedimentary rhythms of organic carbon burial and lithological composition in the Songliao Basin but also influenced the enrichment characteristics and sweet spot distribution of Gulong shale oil.
文摘This paper focuses on propagating perturbed two-body motion using orbital elements combined with a novel integration technique.While previous studies show that Modified Chebyshev Picard Iteration(MCPI)is a powerful tool used to propagate position and velocity,the present results show that using orbital elements to propagate the state vector reduces the number of MCPI iterations and nodes required,which is especially useful for reducing the computation time when including computationally-intensive calculations such as Spherical Harmonic gravity,and it also converges for>5.5x as many revolutions using a single segment when compared with cartesian propagation.Results for the Classical Orbital Elements and the Modified Equinoctial Orbital Elements(the latter provides singularity-free solutions)show that state propagation using these variables is inherently well-suited to the propagation method chosen.Additional benefits are achieved using a segmentation scheme,while future expansion to the two-point boundary value problem is expected to increase the domain of convergence compared with the cartesian case.MCPI is an iterative numerical method used to solve linear and nonlinear,ordinary differential equations(ODEs).It is a fusion of orthogonal Chebyshev function approximation with Picard iteration that approximates a long-arc trajectory at every iteration.Previous studies have shown that it outperforms the state of the practice numerical integrators of ODEs in a serial computing environment;since MCPI is inherently massively parallelizable,this capability is expected to increase the computational efficiency of the method presented.
基金supported by the National Natural Science Foundation of China(52302240)the Macao Young Scholars Program(AM2023011)the Yuanguang Scholars Program,Hebei University of Technology(282022554)。
文摘Lithium-sulfur(Li-S)batteries are considered a potential candidate for next-generation energy-dense and sustainable energy storage.However,the slow conversion and severe shuttle of polysulfides(LiPSs)result in rapid performance degradation over long-term cycling.Herein,we report a high-entropy single-atom(HE-SA)catalyst to regulate the multi-step conversion of LiPS to attain a high-performance Li-S battery.Both the density functional theory calculations and the experimental results prove that the Fe atomic site with high spin configurations strongly interacts with Li_(2)S_(4)through d-p and s-p synergistic orbital hybridization which facilitates the reduction of LiPS.Moreover,S-dominant p-d hybridization between Li_(2)S and a high-spin Mn site weakens the Li-S bond and facilitates the rapid sulfur evolution reaction.Consequently,the Li-S battery with a bifunctional HE-SA catalyst shows an ultralow capacity decay of 0.026% per cycle over 1900 cycles at 1 C.This work proposes a high-entropy strategy for sculpting electronic structures to enable spin and orbital hybridization modulation in advanced catalysts toward longcycling Li-S batteries.
文摘In February 2025,a startup satellite manufacturer,Albedo(Broomfield,CO,USA)is expected to launch its first satellite,Clarity-1,into orbit aboard SpaceX’s Transporter-13,a Falcon 9 rideshare mission[1].Like many imaging satellites,Clarity-1’s mis-sion will be to take high-resolution aerial photos for clients in var-ious economic sectors including agriculture,insurance,energy,mapping,utilities,and defense.What makes this satellite unique is both its industry-leading 10 cm spatial resolution and its extre-mely low orbit of 200 km,far closer to Earth than the 450 km or higher orbits of most of its peers with similar missions.
基金co-supported by the Guangdong Major Project of Basic and Applied Basic Research,China(No.2019B030302001)the Guangdong Basic and Applied Basic Research Foundation,China(No.2022A1515110236)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University,China(No.23xkjc001)。
文摘The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin project delineates detailed requirements for orbit determination during both the launch phase and subsequent scientific experimentation.This paper pioneers the investigation of Precise Orbit Determination(POD)for Tian Qin utilizing the third generation of Bei Dou global navigation satellite system(BDS-3)Inter-Satellite Link(ISL)through simulation.By analyzing the visibility,the feasibility of using BDS-3 ISLs for Tian Qin POD is explored.Furthermore,a refined Solar Radiation Pressure(SRP)model is developed,and the POD accuracy of Tian Qin is assessed,considering factors such as arc length,ranging intervals,and error sources.The results indicate the following:(A)Visibility between Tian Qin and BDS-3 satellites is intermittent,with an average of 10.6 BDS-3 satellites visible to Tian Qin,and the average Root Mean Square(RMS)-value of Position Dilution of Precision(PDOP)for Tian Qin is 48.13.(B)POD accuracy improves with shorter ranging intervals.(C)The error in ephemeris is the dominant factor affecting the POD accuracy.(D)The establishment of three links between Tian Qin and the BDS-3 satellites satisfies the POD requirements of Tian Qin.With a ranging interval of 600 s and over a 7-day arc,the average three-Dimensional(3D)position accuracy of the three Tian Qin satellites is 1.35 m,while the 3D velocity accuracy is 0.08 mm/s.
基金Supported by the National Natural Science Foundation of China (No.81471649)Beijing Municipal Science and Technology Commission (No. Z171100000117001)
文摘AIM: To investigate the diffusion changes in both the optic nerve and optic tract in orbital space-occupying lesion patients with decreased visual acuity, and its clinical significance using probabilistic diffusion tractography(PDT). METHODS: Twenty patients with orbital space-occupying lesions and 25 age-and gender-matched healthy persons were included. All patients and controls underwent routine orbital magnetic resonance imaging and diffusion tensor imaging(DTI), using a 3.0 T magnetic resonance scanner(Trio Tim Siemens). After the image data were preprocessed, each DTI parameters of the optic nerve and optic tract was obtained by PDT, including fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD) and radial diffusivity(RD). The asymmetry index(AI) of each parameter was calculated. Compared the parameters of the affected side optic nerve and ipsilateral optic tract with the contralateral side by paired sample t-test;compared AI of parameters of optic nerve and optic tract between the patient group and the control group by independent sample t-test. Patients were divided into threesubgroups according to the low vision grade standard of WHO, compared the FA and AI of FA between the three subgroups by single factor variance analysis. RESULTS: The affected side optic nerve presented significantly decreased FA, increased MD, AD, and RD values compared to the unaffected side(P<0.05). The AI of FA, MD, AD, and RD of optic nerve in the patients was significantly higher than that of the controls(P<0.05). The comparison results of the optic tract showed that there was no significant difference between the patient group and control group in terms of the bilateral optic tracts in patients(P>0.05). The AIs of the FA value of the optic nerve in the eyesight <0.1 subgroup was significantly higher than that in the other groups(P<0.05). CONCLUSION: FA, MD, AD, and RD of the affected side optic nerve of the orbital space-occupying lesions have significantly changed, the FA value is the most sensitive. The PDT could be a useful tool to provide valid quantitative markers of optic nerve injuries and evaluate the severity of orbital diseases, which other examinations cannot be acquired.
基金supported by the National Natural Science Foundation of China(No.12022214)the National Key R&D Program of China(No.2020YFC2201200)。
文摘This paper proposes an optimal,robust,and efficient guidance scheme for the perturbed minimum-time low-thrust transfer toward the geostationary orbit.The Earth’s oblateness perturbation and shadow are taken into account.It is difficult for a Lyapunov-based or trajectory-tracking guidance method to possess multiple characteristics at the same time,including high guidance optimality,robustness,and onboard computational efficiency.In this work,a concise relationship between the minimum-time transfer problem with orbital averaging and its optimal solution is identified,which reveals that the five averaged initial costates that dominate the optimal thrust direction can be approximately determined by only four initial modified equinoctial orbit elements after a coordinate transformation.Based on this relationship,the optimal averaged trajectories constituting the training dataset are randomly generated around a nominal averaged trajectory.Five polynomial regression models are trained on the training dataset and are regarded as the costate estimators.In the transfer,the spacecraft can obtain the real-time approximate optimal thrust direction by combining the costate estimations provided by the estimators with the current state at any time.Moreover,all these computations onboard are analytical.The simulation results show that the proposed guidance scheme possesses extremely high guidance optimality,robustness,and onboard computational efficiency.
