There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute thre...There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2"~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components.展开更多
Atmospheric turbulence(AT) induced crosstalk can significantly impair the performance of a free-space optical(FSO)communication link using orbital angular momentum(OAM) multiplexing.In this paper,we propose a mu...Atmospheric turbulence(AT) induced crosstalk can significantly impair the performance of a free-space optical(FSO)communication link using orbital angular momentum(OAM) multiplexing.In this paper,we propose a multiple-user detection(MUD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link.First,we present a MUD equivalent communication model for an OAM-multiplexed FSO communication link under AT.In the equivalent model,each input bit stream represents one user's information.The deformed OAM spatial modes caused by AT,instead of the pure OAM spatial modes,are used as information carriers,and the overlapping between the deformed OAM spatial modes are computed as the correlation coefficients between the users.Then,we present a turbulence mitigation scheme based on MUD idea to enhance AT tolerance of the OAM-multiplexed FSO communication link.In the proposed scheme,the crosstalk caused by AT is used as a useful component to deduce users' information.The numerical results show that the performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme.When the turbulence strength C_n^2 is 1 × 10^(-15) m^(-2/3),the transmission distance is 1000 m and the channel signal-to-noise ratio(SNR)is 26 dB,the bit-error-rate(BER) performance of four spatial multiplexed OAM modes l_m = + 1,+2,+3,+4 are all close to 10-5,and there is a 2-3 fold increase in the BER performance in comparison with those results without the proposed scheme.In addition,the proposed scheme is more effective for an OAM-multiplexed FSO communication link with a larger OAM mode topological charge interval.The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link.展开更多
AIM:To assess the role of orthoptics in referring patients with orbital floor blowout fracture(OFBF)for conservative or surgical treatment and based on the results,to propose a scoring system for such decision making....AIM:To assess the role of orthoptics in referring patients with orbital floor blowout fracture(OFBF)for conservative or surgical treatment and based on the results,to propose a scoring system for such decision making.METHODS:A retrospective analysis of 69 patients with OFBF was performed(35 treated conservatively,34 surgically).The role of orthoptics in referring to surgery or conservative treatment was retrospectively evaluated,the factors with the highest significance for decision making were identified,and a scoring system proposed using Logistic regression.RESULTS:According to defined criteria,the treatment was unsuccessful in 2(6%)surgically treated and only in one(3%)conservatively treated patient.The proposed scoring system includes the defect size and several values resulting from the orthoptic examination,the elevation of the eyebulb measured on Lancaster screen being the most significant.CONCLUSION:The study demonstrates the benefits of orthoptic examination when making decisions on conservative or surgical treatment and for diagnosing ocular motility disorder(with or without binocular diplopia)in OFBF patients.The proposed scoring system could,following verification in a prospective study,become a valuable adjunctive tool.展开更多
In this paper, the extended Pade approximant is used to construct the homoclinic and the heteroclinic trajectories in nonlinear dynamical systems that are asymmetric at origin. Meanwhile, the conservative system, the ...In this paper, the extended Pade approximant is used to construct the homoclinic and the heteroclinic trajectories in nonlinear dynamical systems that are asymmetric at origin. Meanwhile, the conservative system, the autonomous system, and the nonautonomous system equations with quadratic and cubic nonlinearities are considered. The disturbance parameter ~ is not limited to being small. The ranges of the values of the linear and the nonlinear term parameters, which are variables, can be determined when the boundary values are satisfied. New conditions for the potentiality and the convergence are posed to make it possible to solve the boundary-value problems formulated for the orbitals and to evaluate the initial amplitude values.展开更多
To assess all available data to compare the efficacy of glucocorticoids treatment and orbital decompression for dysthyroid optic neuropathy(DON).PubMed,EMBASE,the Cochrane Library databases as well as other sources we...To assess all available data to compare the efficacy of glucocorticoids treatment and orbital decompression for dysthyroid optic neuropathy(DON).PubMed,EMBASE,the Cochrane Library databases as well as other sources were searched by two independent reviewers followed by extensive hand-searching for the identification of relevant studies.The primary outcomes were the improvement in visual acuity and responder rate.Secondary outcomes were the proptosis reduction,change in diplopia,and clinical activity score(CAS).One randomized controlled trial,three retrospective case series and one prospective case series met the inclusion criteria.They were divided into intravenous high-dose glucocorticoids(ivGC)group and orbital decompression(OD)group.Both groups demonstrated improvement in visual acuity.In addition,the proportion of patients with improved vision in OD group was higher than that in ivGC group(P<0.001).Post-treatment proptosis reduction was also reported in both groups.Overall,weighted mean in proptosis reduction estimated at 1.64 and 5.45 mm in patients treated with ivGC and OD respectively.This study also presented results regarding pre-existing and new-onset diplopia.Apart from diplopia,a wide variety of minor and major complications were noted in 5 included studies.The most common complication in ivGC group and OD group was Cushing's syndrome and epistaxis respectively.The present systematic review shows that both glucocorticoids treatment and OD are effective in treating DON and OD may work better in improving visual acuity and reducing proptosis.However,high-quality,large-sample,controlled studies need to be performed in the future.展开更多
In the interaction of laser-plasma the system of Zakharov equation plays an important role.This system attracted many scientists' wide interest and attention.And the formation, evolution and interaction of the Lan...In the interaction of laser-plasma the system of Zakharov equation plays an important role.This system attracted many scientists' wide interest and attention.And the formation, evolution and interaction of the Langmuir solutions differ from solutions of the KDV equation. Here we consider the following generalized Zakharov展开更多
A new flexible tether-net space robotic system used to capture space debris is presented in this paper. With a mass point assumption, a dynamic model of the tether-net system was established in orbital frame by applyi...A new flexible tether-net space robotic system used to capture space debris is presented in this paper. With a mass point assumption, a dynamic model of the tether-net system was established in orbital frame by applying Lagrange Equations. In order to investigate the net in-plane trajectories after being cast, the non-controlled R-bar and V-bar captures were simulated with ignoring the out-of-plane libration, and the effect of in-plane libration on the trajectories of the capture net was demonstrated by simulation results. With an effort to damp the in-plane libration, the control scheme based on tether tension was investigated, then an integrated control scheme was proposed by introducing thrusters into the system, and the nonlinear close-loop dynamics was linearised by feedforward strategy. Simulation results show that the feedforward controller is effective for in-plane libration damping and enables the capture net to track an expected trajectory.展开更多
We theoretically study the charge order and orbital magnetic properties of a new type of antiferromagnetic kagome metal FeGe.Based on first-principles density functional theory calculations,we study the electronic str...We theoretically study the charge order and orbital magnetic properties of a new type of antiferromagnetic kagome metal FeGe.Based on first-principles density functional theory calculations,we study the electronic structures,Fermi-surface quantum fluctuations,as well as phonon properties of the antiferromagnetic kagome metal FeGe.It is found that charge density wave emerges in such a system due to a subtle cooperation between electron-electron interactions and electron–phonon couplings,which gives rise to an unusual scenario of interaction-triggered phonon instabilities,and eventually yields a charge density wave(CDW)state.We further show that,in the CDW phase,the ground-state current density distribution exhibits an intriguing star-of-David pattern,leading to flux density modulation.The orbital fluxes(or current loops)in this system emerge as a result of the subtle interplay between magnetism,lattice geometries,charge order,and spin-orbit coupling(SOC),which can be described by a simple,yet universal,tight-binding theory including a Kane-Mele-type SOC term and a magnetic exchange interaction.We further study the origin of the peculiar step-edge states in FeGe,which sheds light on the topological properties and correlation effects in this new type of kagome antiferromagnetic material.展开更多
The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,...The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain unclear.Therefore,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory calculations.For a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic activities.The hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR performance.The maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR performance.The asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and positions.This work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs.展开更多
In order to understand the properties of the spin system with orbital degeneracy, we first study the ground state of the SU(4) spin-orbital model on a square lattice. The mean-field results suggest that for a small Hu...In order to understand the properties of the spin system with orbital degeneracy, we first study the ground state of the SU(4) spin-orbital model on a square lattice. The mean-field results suggest that for a small Hund's interaction, the flavor liquid state is stable against the solid state, but with sufficient deviation from the SU(4) limit the long-range order may be attained in 2D system. Furthermore, we employ a variational approach to calculate the phase diagram of the ground state and the temperature-dependent susceptibility by taking into account the Hund's interaction and the anisotropy in orbital wavefunctions. Finally, the implications for the experimental observations on the material, , are discussed.展开更多
We prove the existence and the orbital stability of standing waves for the nonau- tonomous Schrodinger system……under suitable conditions on the coefficient functions a and b. We follow the idea of analyzing the comp...We prove the existence and the orbital stability of standing waves for the nonau- tonomous Schrodinger system……under suitable conditions on the coefficient functions a and b. We follow the idea of analyzing the compactness of minimizing sequence of the constrained minimization problems.展开更多
AIM:To compare the exposure rate,infection rate,percentage of enhancement,and success rate between Medpor and the three-dimensional printed polyethylene(3DP-PE)orbital implant in a preliminary report.METHODS:This pros...AIM:To compare the exposure rate,infection rate,percentage of enhancement,and success rate between Medpor and the three-dimensional printed polyethylene(3DP-PE)orbital implant in a preliminary report.METHODS:This prospective,randomized,equivalence,controlled trial was conducted at two institutes.The equivalent margin was±10%.The sample size for the equivalence trial was 174 participants per group.Patients who were eligible for enucleations received either Medpor or 3DP-PE implants based on a randomized block of six.The surgeries were performed by five oculoplastic surgeons.The assessor and patients were masked.The magnetic resonance imaging(MRI)of the orbit was performed at least 6mo after operation and the fibrovascular ingrowth was analyzed using the Image J software.Follow-up continued at least 1y after surgery.The intention to treat and per protocol approaches were used.RESULTS:Totally 128 patients met the criteria in the report.Fifty Medpor and 553DP-PE cases completed the trial.The most common cause of blindness was trauma.The mean follow-up times of Medpor and 3DP-PE were 33 and 40mo respectively.The exposure rate was not statistically significant between two groups(6.0%and 7.3%),P<0.05,95%CI(-9.8%,+12.0%).The success rates were 94%(Medpor)and 92.7%(3DP-PE).No postoperative infection was reported.Nine patients had MRI tests and two had implant exposures with 66.3% enhancement at 75mo(Medpor)and 58% enhancement at 57mo(3DP-PE)postoperatively.CONCLUSION:There is no statistically significant difference in exposure rate and success rate between Medpor and 3DP-PE in enucleation in the report.However,we cannot conclude that they are equivalent in terms of the exposure rate and success rate because the 95%CI is wider than±10%.The infection rate is equivalent in both groups.展开更多
The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in ele...The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.展开更多
Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the tra...Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the transmitter and receiver must be parallel and coaxial;otherwise,the accuracy of mode detection at the receiver can be seriously influenced.In this paper,we design an OAM millimeter-wave communication system for overcoming the above limitation.Specifically,the first contribution is that the power distribution between different OAM modes and the capacity of the system with different mode sets are analytically derived for performance analysis.The second contribution lies in that a novel mode selection scheme is proposed to reduce the total interference between different modes.Numerical results show that system performance is less affected by the offset when the mode set with smaller modes or larger intervals is selected.展开更多
Orbital angular momentum(OAM)holography has become a promising technique in information encryption,data storage and opto-electronic computing,owing to the infinite topological charge of one single OAM mode and the ort...Orbital angular momentum(OAM)holography has become a promising technique in information encryption,data storage and opto-electronic computing,owing to the infinite topological charge of one single OAM mode and the orthogonality of different OAM modes.In this paper,we propose a novel OAM hologram generation method based on a densely connected U-net(DCU),where the densely connected convolution blocks(DCB)replace the convolution blocks of the U-net.Importantly,the reconstruction process of the OAM hologram is integrated into DCU as its output layer,so as to eliminate the requirement to prepare training data for the OAM hologram,which is required by conventional neural networks through an iterative algorithm.The experimental and simulation results show that the OAM hologram can rapidly be generated with the well-trained DCU,and the reconstructed image's quality from the generated OAM hologram is significantly improved in comparison with those from the Gerchberg-Saxton generation method,the Gerchberg-Saxton based generation method and the U-net method.In addition,a 10-bit OAM multiplexing hologram scheme is numerically demonstrated to have a high capacity with OAM hologram.展开更多
Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstruct...Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstructed from an OAM-multiplexing hologram. However, the traditional design of an OAM hologram is constrained by the helical mode index of the selected OAM mode, for a larger helical mode index OAM mode has a bigger sampling distance, and the crosstalk is produced for different sampling distances for different OAM modes. In this paper, we present the design of the OAM hologram based on a Bessel–Gaussian beam, which is non-diffractive and has a self-healing property during its propagation. The Fourier transform of the Bessel–Gaussian beam is the perfect vortex mode that has the fixed ring radius for different OAM modes. The results of simulation and experiment have demonstrated the feasibility of the generation of the OAM hologram with the Bessel–Gaussian beam. The quality of the reconstructed holographic image is increased, and the security is enhanced. Additionally, the anti-interference property is improved owing to its self-healing property of the Bessel-OAM holography.展开更多
We theoretically studied the dynamic properties of the skyrmion driven by electromagnetic(EM)waves with spin angular momentum(SAM)and orbital angular momentum(OAM)using micromagnetic simulations.First,the guiding cent...We theoretically studied the dynamic properties of the skyrmion driven by electromagnetic(EM)waves with spin angular momentum(SAM)and orbital angular momentum(OAM)using micromagnetic simulations.First,the guiding centers of the skyrmion driven by EM waves with SAM,i.e.,left-handed and right-handed circularly polarized EM waves,present circular trajectories,while present elliptical trajectories under linear EM waves driving due to the superposition of oppositely polarized wave components.Second,the trajectories of the skyrmion driven by EM waves with OAM demonstrate similar behavior to that driven by linearly polarized EM waves.Because the wave vector intensity varies with the phase for both linearly polarized EM waves and EM waves with OAM,the angular momentum is transferred to the skyrmion non-uniformly,while the angular momentum is transferred to the skyrmion uniformly for left-handed and right-handed circularly polarized EM driving.Third,the dynamic properties of the skyrmion driven by EM waves with both SAM and OAM are investigated.It is found that the dynamic trajectories exhibit more complex behavior due to the contributions or competition of SAM and OAM.We investigate the characteristics of intrinsic gyration modes and frequency-dependent trajectories.Our research may provide insight into the dynamic properties of skyrmion manipulated by EM waves with SAM or OAM and provide a method for controlling skyrmion in spintronic devices.展开更多
Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept ...Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.展开更多
Fractional orbital angular momentum(OAM) vortex beams present a promising way to increase the data throughput in optical communication systems. Nevertheless, high-precision recognition of fractional OAM with different...Fractional orbital angular momentum(OAM) vortex beams present a promising way to increase the data throughput in optical communication systems. Nevertheless, high-precision recognition of fractional OAM with different propagation distances remains a significant challenge. We develop a convolutional neural network(CNN)method to realize high-resolution recognition of OAM modalities, leveraging asymmetric Bessel beams imbued with fractional OAM. Experimental results prove that our method achieves a recognition accuracy exceeding 94.3% for OAM modes, with an interval of 0.05, and maintains a high recognition accuracy above 92% across varying propagation distances. The findings of our research will be poised to significantly contribute to the deployment of fractional OAM beams within the domain of optical communications.展开更多
Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical pr...Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).展开更多
文摘There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2"~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61271238 and 61475075)the Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology,Ministry of Education,China(Grant No.NYKL2015011)+1 种基金the Postgraduate Innovation Research Plan of Jiangsu Province,China(Grant No.CXZZ13_0489)the University Natural Science Foundation of Jiangsu Province,China(Grant No.16KJB510037)
文摘Atmospheric turbulence(AT) induced crosstalk can significantly impair the performance of a free-space optical(FSO)communication link using orbital angular momentum(OAM) multiplexing.In this paper,we propose a multiple-user detection(MUD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link.First,we present a MUD equivalent communication model for an OAM-multiplexed FSO communication link under AT.In the equivalent model,each input bit stream represents one user's information.The deformed OAM spatial modes caused by AT,instead of the pure OAM spatial modes,are used as information carriers,and the overlapping between the deformed OAM spatial modes are computed as the correlation coefficients between the users.Then,we present a turbulence mitigation scheme based on MUD idea to enhance AT tolerance of the OAM-multiplexed FSO communication link.In the proposed scheme,the crosstalk caused by AT is used as a useful component to deduce users' information.The numerical results show that the performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme.When the turbulence strength C_n^2 is 1 × 10^(-15) m^(-2/3),the transmission distance is 1000 m and the channel signal-to-noise ratio(SNR)is 26 dB,the bit-error-rate(BER) performance of four spatial multiplexed OAM modes l_m = + 1,+2,+3,+4 are all close to 10-5,and there is a 2-3 fold increase in the BER performance in comparison with those results without the proposed scheme.In addition,the proposed scheme is more effective for an OAM-multiplexed FSO communication link with a larger OAM mode topological charge interval.The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link.
基金the Ministry of Health,Czech Republic Conceptual Development of Research Organization(FNOs/2017).
文摘AIM:To assess the role of orthoptics in referring patients with orbital floor blowout fracture(OFBF)for conservative or surgical treatment and based on the results,to propose a scoring system for such decision making.METHODS:A retrospective analysis of 69 patients with OFBF was performed(35 treated conservatively,34 surgically).The role of orthoptics in referring to surgery or conservative treatment was retrospectively evaluated,the factors with the highest significance for decision making were identified,and a scoring system proposed using Logistic regression.RESULTS:According to defined criteria,the treatment was unsuccessful in 2(6%)surgically treated and only in one(3%)conservatively treated patient.The proposed scoring system includes the defect size and several values resulting from the orthoptic examination,the elevation of the eyebulb measured on Lancaster screen being the most significant.CONCLUSION:The study demonstrates the benefits of orthoptic examination when making decisions on conservative or surgical treatment and for diagnosing ocular motility disorder(with or without binocular diplopia)in OFBF patients.The proposed scoring system could,following verification in a prospective study,become a valuable adjunctive tool.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11072168 and 10872141)
文摘In this paper, the extended Pade approximant is used to construct the homoclinic and the heteroclinic trajectories in nonlinear dynamical systems that are asymmetric at origin. Meanwhile, the conservative system, the autonomous system, and the nonautonomous system equations with quadratic and cubic nonlinearities are considered. The disturbance parameter ~ is not limited to being small. The ranges of the values of the linear and the nonlinear term parameters, which are variables, can be determined when the boundary values are satisfied. New conditions for the potentiality and the convergence are posed to make it possible to solve the boundary-value problems formulated for the orbitals and to evaluate the initial amplitude values.
基金Supported by the Natural Science Foundation of China(No.81770926)the Natural Key Research and Development Program of China(No.2016YFC1101200)。
文摘To assess all available data to compare the efficacy of glucocorticoids treatment and orbital decompression for dysthyroid optic neuropathy(DON).PubMed,EMBASE,the Cochrane Library databases as well as other sources were searched by two independent reviewers followed by extensive hand-searching for the identification of relevant studies.The primary outcomes were the improvement in visual acuity and responder rate.Secondary outcomes were the proptosis reduction,change in diplopia,and clinical activity score(CAS).One randomized controlled trial,three retrospective case series and one prospective case series met the inclusion criteria.They were divided into intravenous high-dose glucocorticoids(ivGC)group and orbital decompression(OD)group.Both groups demonstrated improvement in visual acuity.In addition,the proportion of patients with improved vision in OD group was higher than that in ivGC group(P<0.001).Post-treatment proptosis reduction was also reported in both groups.Overall,weighted mean in proptosis reduction estimated at 1.64 and 5.45 mm in patients treated with ivGC and OD respectively.This study also presented results regarding pre-existing and new-onset diplopia.Apart from diplopia,a wide variety of minor and major complications were noted in 5 included studies.The most common complication in ivGC group and OD group was Cushing's syndrome and epistaxis respectively.The present systematic review shows that both glucocorticoids treatment and OD are effective in treating DON and OD may work better in improving visual acuity and reducing proptosis.However,high-quality,large-sample,controlled studies need to be performed in the future.
基金The research is supported by the Scientific Research Foundation of Yunnan Provincial Departmentthe Natural Science Foundation of Yunnan Province(No.2005A0026M).
文摘In the interaction of laser-plasma the system of Zakharov equation plays an important role.This system attracted many scientists' wide interest and attention.And the formation, evolution and interaction of the Langmuir solutions differ from solutions of the KDV equation. Here we consider the following generalized Zakharov
基金Sponsored by the High Technology Research & Development Program of China(Grant No.2002AA742012)
文摘A new flexible tether-net space robotic system used to capture space debris is presented in this paper. With a mass point assumption, a dynamic model of the tether-net system was established in orbital frame by applying Lagrange Equations. In order to investigate the net in-plane trajectories after being cast, the non-controlled R-bar and V-bar captures were simulated with ignoring the out-of-plane libration, and the effect of in-plane libration on the trajectories of the capture net was demonstrated by simulation results. With an effort to damp the in-plane libration, the control scheme based on tether tension was investigated, then an integrated control scheme was proposed by introducing thrusters into the system, and the nonlinear close-loop dynamics was linearised by feedforward strategy. Simulation results show that the feedforward controller is effective for in-plane libration damping and enables the capture net to track an expected trajectory.
基金supported by the National Natural Science Foundation of China(Grant No.12174257)the National Key R&D program of China(Grant No.2020YFA0309601)+1 种基金the Science and Technology Commission of the Shanghai Municipality(Grant No.21JC1405100)the Start-Up Grant of ShanghaiTech University。
文摘We theoretically study the charge order and orbital magnetic properties of a new type of antiferromagnetic kagome metal FeGe.Based on first-principles density functional theory calculations,we study the electronic structures,Fermi-surface quantum fluctuations,as well as phonon properties of the antiferromagnetic kagome metal FeGe.It is found that charge density wave emerges in such a system due to a subtle cooperation between electron-electron interactions and electron–phonon couplings,which gives rise to an unusual scenario of interaction-triggered phonon instabilities,and eventually yields a charge density wave(CDW)state.We further show that,in the CDW phase,the ground-state current density distribution exhibits an intriguing star-of-David pattern,leading to flux density modulation.The orbital fluxes(or current loops)in this system emerge as a result of the subtle interplay between magnetism,lattice geometries,charge order,and spin-orbit coupling(SOC),which can be described by a simple,yet universal,tight-binding theory including a Kane-Mele-type SOC term and a magnetic exchange interaction.We further study the origin of the peculiar step-edge states in FeGe,which sheds light on the topological properties and correlation effects in this new type of kagome antiferromagnetic material.
基金supported by the National Natural Science Foundation of China(21905253,51973200,and 52122308)the Natural Science Foundation of Henan(202300410372)the National Supercomputing Center in Zhengzhou
文摘The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is challenging.Two-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising SACs.Up to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain unclear.Therefore,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory calculations.For a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic activities.The hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR performance.The maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR performance.The asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and positions.This work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs.
文摘In order to understand the properties of the spin system with orbital degeneracy, we first study the ground state of the SU(4) spin-orbital model on a square lattice. The mean-field results suggest that for a small Hund's interaction, the flavor liquid state is stable against the solid state, but with sufficient deviation from the SU(4) limit the long-range order may be attained in 2D system. Furthermore, we employ a variational approach to calculate the phase diagram of the ground state and the temperature-dependent susceptibility by taking into account the Hund's interaction and the anisotropy in orbital wavefunctions. Finally, the implications for the experimental observations on the material, , are discussed.
文摘We prove the existence and the orbital stability of standing waves for the nonau- tonomous Schrodinger system……under suitable conditions on the coefficient functions a and b. We follow the idea of analyzing the compactness of minimizing sequence of the constrained minimization problems.
基金Supported by the Mettapracharak grantThai Government Budget grant+1 种基金Health Systems Research Institute grantNational Science and Technology Development Agency grant.
文摘AIM:To compare the exposure rate,infection rate,percentage of enhancement,and success rate between Medpor and the three-dimensional printed polyethylene(3DP-PE)orbital implant in a preliminary report.METHODS:This prospective,randomized,equivalence,controlled trial was conducted at two institutes.The equivalent margin was±10%.The sample size for the equivalence trial was 174 participants per group.Patients who were eligible for enucleations received either Medpor or 3DP-PE implants based on a randomized block of six.The surgeries were performed by five oculoplastic surgeons.The assessor and patients were masked.The magnetic resonance imaging(MRI)of the orbit was performed at least 6mo after operation and the fibrovascular ingrowth was analyzed using the Image J software.Follow-up continued at least 1y after surgery.The intention to treat and per protocol approaches were used.RESULTS:Totally 128 patients met the criteria in the report.Fifty Medpor and 553DP-PE cases completed the trial.The most common cause of blindness was trauma.The mean follow-up times of Medpor and 3DP-PE were 33 and 40mo respectively.The exposure rate was not statistically significant between two groups(6.0%and 7.3%),P<0.05,95%CI(-9.8%,+12.0%).The success rates were 94%(Medpor)and 92.7%(3DP-PE).No postoperative infection was reported.Nine patients had MRI tests and two had implant exposures with 66.3% enhancement at 75mo(Medpor)and 58% enhancement at 57mo(3DP-PE)postoperatively.CONCLUSION:There is no statistically significant difference in exposure rate and success rate between Medpor and 3DP-PE in enucleation in the report.However,we cannot conclude that they are equivalent in terms of the exposure rate and success rate because the 95%CI is wider than±10%.The infection rate is equivalent in both groups.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52161135302,22105087)the Postdoctoral Research Foundation of China(Grant No.2022M721360)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210446)。
文摘The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to date.Herein,we successfully realize the structural transformation of Pd Cu metallic aerogels(MAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing treatment.Specifically,the BCC Pd Cu MAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V vs.reversible hydrogen electrode,outperforming than those of FCC Pd Cu MAs.Under the membrane electrode assembly system,BCC Pd Cu MAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu MAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR performance.Our work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.
基金supported in part by The National Natural Science Foundation of China(62071255,62171232,61771257)The Major Projects of the Natural Science Foundation of the Jiangsu Higher Education Institutions(20KJA510009)+3 种基金The Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications),Ministry of Education(JZNY201914)The open research fund of National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology,Nanjing University of Posts and Telecommunications(KFJJ20170305)The Research Fund of Nanjing University of Posts and Telecommunications(NY218012)Henan province science and technology research projects High and new technology(No.182102210106).
文摘Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the transmitter and receiver must be parallel and coaxial;otherwise,the accuracy of mode detection at the receiver can be seriously influenced.In this paper,we design an OAM millimeter-wave communication system for overcoming the above limitation.Specifically,the first contribution is that the power distribution between different OAM modes and the capacity of the system with different mode sets are analytically derived for performance analysis.The second contribution lies in that a novel mode selection scheme is proposed to reduce the total interference between different modes.Numerical results show that system performance is less affected by the offset when the mode set with smaller modes or larger intervals is selected.
基金supported by the National Natural Science Foundation of China(Grant Nos.62375140 and 61871234)the Open Research Fund of National Laboratory of Solid State Microstructures(Grant No.M36055).
文摘Orbital angular momentum(OAM)holography has become a promising technique in information encryption,data storage and opto-electronic computing,owing to the infinite topological charge of one single OAM mode and the orthogonality of different OAM modes.In this paper,we propose a novel OAM hologram generation method based on a densely connected U-net(DCU),where the densely connected convolution blocks(DCB)replace the convolution blocks of the U-net.Importantly,the reconstruction process of the OAM hologram is integrated into DCU as its output layer,so as to eliminate the requirement to prepare training data for the OAM hologram,which is required by conventional neural networks through an iterative algorithm.The experimental and simulation results show that the OAM hologram can rapidly be generated with the well-trained DCU,and the reconstructed image's quality from the generated OAM hologram is significantly improved in comparison with those from the Gerchberg-Saxton generation method,the Gerchberg-Saxton based generation method and the U-net method.In addition,a 10-bit OAM multiplexing hologram scheme is numerically demonstrated to have a high capacity with OAM hologram.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.62375140 and 62001249)the Open Research Fund of the National Laboratory of Solid State Microstructures (Grant No.M36055)。
文摘Orbital angular momentum(OAM), as a new degree of freedom, has recently been applied in holography technology.Due to the infinite helical mode index of OAM mode, a large number of holographic images can be reconstructed from an OAM-multiplexing hologram. However, the traditional design of an OAM hologram is constrained by the helical mode index of the selected OAM mode, for a larger helical mode index OAM mode has a bigger sampling distance, and the crosstalk is produced for different sampling distances for different OAM modes. In this paper, we present the design of the OAM hologram based on a Bessel–Gaussian beam, which is non-diffractive and has a self-healing property during its propagation. The Fourier transform of the Bessel–Gaussian beam is the perfect vortex mode that has the fixed ring radius for different OAM modes. The results of simulation and experiment have demonstrated the feasibility of the generation of the OAM hologram with the Bessel–Gaussian beam. The quality of the reconstructed holographic image is increased, and the security is enhanced. Additionally, the anti-interference property is improved owing to its self-healing property of the Bessel-OAM holography.
文摘We theoretically studied the dynamic properties of the skyrmion driven by electromagnetic(EM)waves with spin angular momentum(SAM)and orbital angular momentum(OAM)using micromagnetic simulations.First,the guiding centers of the skyrmion driven by EM waves with SAM,i.e.,left-handed and right-handed circularly polarized EM waves,present circular trajectories,while present elliptical trajectories under linear EM waves driving due to the superposition of oppositely polarized wave components.Second,the trajectories of the skyrmion driven by EM waves with OAM demonstrate similar behavior to that driven by linearly polarized EM waves.Because the wave vector intensity varies with the phase for both linearly polarized EM waves and EM waves with OAM,the angular momentum is transferred to the skyrmion non-uniformly,while the angular momentum is transferred to the skyrmion uniformly for left-handed and right-handed circularly polarized EM driving.Third,the dynamic properties of the skyrmion driven by EM waves with both SAM and OAM are investigated.It is found that the dynamic trajectories exhibit more complex behavior due to the contributions or competition of SAM and OAM.We investigate the characteristics of intrinsic gyration modes and frequency-dependent trajectories.Our research may provide insight into the dynamic properties of skyrmion manipulated by EM waves with SAM or OAM and provide a method for controlling skyrmion in spintronic devices.
基金financially supported by the National Natural Science Foundation of China(21972068,22072067,22232004)the High-level Talents Project of Jinling Institute of Technology(jit-b-202164)。
文摘Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.
基金supported by the National Natural Science Foundation of China (Grant Nos.12174338 and 11874321)。
文摘Fractional orbital angular momentum(OAM) vortex beams present a promising way to increase the data throughput in optical communication systems. Nevertheless, high-precision recognition of fractional OAM with different propagation distances remains a significant challenge. We develop a convolutional neural network(CNN)method to realize high-resolution recognition of OAM modalities, leveraging asymmetric Bessel beams imbued with fractional OAM. Experimental results prove that our method achieves a recognition accuracy exceeding 94.3% for OAM modes, with an interval of 0.05, and maintains a high recognition accuracy above 92% across varying propagation distances. The findings of our research will be poised to significantly contribute to the deployment of fractional OAM beams within the domain of optical communications.
基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFE0202700 and 2023YFA1406500)the National Natural Science Foundation of China(Grant Nos.11974422 and 12104504)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)Fundamental Research Funds for the Central Universities,and Research Funds of Renmin University,China(Grant No.22XNKJ30)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2023 of Renmin University,China。
文摘Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).