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ORBIT评分与HAS-BLED评分对心脏瓣膜置换术后华法林抗凝出血风险的预测价值比较
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作者 赵慧明 刘勇 +3 位作者 粟丽 夏浩然 陈婷 王亚莉 《实用临床医药杂志》 CAS 2024年第6期83-87,共5页
目的比较ORBIT评分与HAS-BLED评分对心脏瓣膜置换术后华法林抗凝出血风险的预测价值。方法回顾性分析304例心脏瓣膜置换术后需行华法林抗凝治疗患者的病例资料,分别根据ORBIT评分和HAS-BLED评分对患者进行风险分层和分组,分析基于不同... 目的比较ORBIT评分与HAS-BLED评分对心脏瓣膜置换术后华法林抗凝出血风险的预测价值。方法回顾性分析304例心脏瓣膜置换术后需行华法林抗凝治疗患者的病例资料,分别根据ORBIT评分和HAS-BLED评分对患者进行风险分层和分组,分析基于不同评分的风险分层与术后华法林抗凝出血事件的相关性,比较2种评分方法风险分层的一致性及其对出血事件的预测价值。结果304例患者中,出血患者32例、未出血患者272例,出血患者的术后ORBIT评分、HAS-BLED评分均高于未出血患者,差异有统计学意义(P<0.05)。基于ORBIT评分划分的中危、高危患者的出血风险分别为低危患者的6.092(95%CI:2.694~13.775)倍、9.373(95%CI:1.465~59.943)倍,基于HAS-BLED评分划分的中危、高危患者的出血风险分别为低危患者的3.750(95%CI:1.383~10.166)倍、14.250(95%CI:5.489~36.995)倍。受试者工作特征曲线分析结果显示,ORBIT评分预测华法林抗凝出血风险的曲线下面积(AUC)为0.646(95%CI:0.589~0.699),敏感度为46.88%,特异度为87.87%,最佳截断值为3分;HAS-BLED评分预测华法林抗凝出血风险的AUC为0.768(95%CI:0.717~0.814),敏感度为75.00%,特异度为69.85%,最佳截断值为2分;Delong检验结果显示,2种评分的AUC差异有统计学意义(D=0.122,95%CI:0.001~0.245,Z=1.962,P<0.05)。结论ORBIT评分和HAS-BLED评分对心脏瓣膜置换术后华法林抗凝出血风险均具有一定预测价值,其中HAS-BLED评分的预测效能更优。 展开更多
关键词 心脏瓣膜置换术 华法林 抗凝 orbit评分 HAS-BLED评分 出血事件
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Unstable periodic orbits analysis in the Qi system
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作者 贾莲 董成伟 +1 位作者 李瀚涛 眭晓红 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期237-248,共12页
We use the variational method to extract the short periodic orbits of the Qi system within a certain topological length.The chaotic dynamical behaviors of the Qi system with five equilibria are analyzed by the means o... We use the variational method to extract the short periodic orbits of the Qi system within a certain topological length.The chaotic dynamical behaviors of the Qi system with five equilibria are analyzed by the means of phase portraits,Lyapunov exponents,and Poincarémaps.Based on several periodic orbits with different sizes and shapes,they are encoded systematically with two letters or four letters for two different sets of parameters.The periodic orbits outside the attractor with complex topology are discovered by accident.In addition,the bifurcations of cycles and the bifurcations of equilibria in the Qi system are explored by different methods respectively.In this process,the rule of orbital period changing with parameters is also investigated.The calculation and classification method of periodic orbits in this study can be widely used in other similar low-dimensional dissipative systems. 展开更多
关键词 CHAOS periodic orbits BIFURCATION Qi system
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A Positioning Method and Realization on Single Satellites in Different Orbits Using TDOA
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作者 Laiding Zhao Xun Zhu +1 位作者 Gengxin Zhang Zhaowen Wang 《China Communications》 SCIE CSCD 2023年第7期108-121,共14页
The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA,the principle is to determine the location of the signal source by using the difference in arrival time and freque... The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA,the principle is to determine the location of the signal source by using the difference in arrival time and frequency of the wireless signal between different receivers.Therefore,ground monitoring stations need to be equipped with more than two antenna receiving stations,and multiple satellites should be able to simultaneously relay the distress signal from the target source in order to achieve the geolocation function.However,when the ground receiving system has only one antenna receiving station,or the target source is in a heavily obscured environment,the ground side is unable to receive the forwarded signals from multiple satellites at the same time,which will make it impossible to locate.To address these problems,in this paper,a time-sharing single satellite geolocations method based on different orbits is proposed for the first time.This method uses one or several low-earth orbit satellites(LEO)and mediumearth orbit satellites(MEO)in the visible area,and the receiving station only needs one pair of receiving antennas to complete the positioning.It can effectively compensate for the shortcomings of the traditional TDOA using the same moment and have better positioning accuracy compared with the single satellite in the same orbit.Due to the limited experimental conditions,this paper tests the navigation satellite using different orbit time-sharing single satellite geolocations,and proves that the positioning method has high positioning accuracy and has certain promotion and application value. 展开更多
关键词 different orbit time-sharing non-convex optimization single satellite TDOA
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Dynamic Electron Orbits in Atomic Hydrogen
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作者 Gurcharn S. Sandhu 《Journal of Modern Physics》 2023年第11期1497-1525,共29页
Even after extensive research in Quantum Mechanics, we are still unable to visualize instant-to-instant motion of an electron in hydrogen atom. That is because in QM treatment, potential energy term has been mistakenl... Even after extensive research in Quantum Mechanics, we are still unable to visualize instant-to-instant motion of an electron in hydrogen atom. That is because in QM treatment, potential energy term has been mistakenly assumed to be time-independent instead of depending on the instant-to-instant varying position of the orbiting electron [1]. This has led to wrong and weird solutions for the electron motion in hydrogen atom. Before the advent of wave mechanics, Sommerfeld model of elliptical electron orbits was able to explain most features of hydrogen spectra, except for the features associated with electron spin and magnetic moment interactions. However, the Sommerfeld elliptical orbits were of kinematic origin and could not provide visualization of instant-to-instant dynamic motion of the orbiting electron. Contrary to the QM perspective, we find that central core of the electron behaves as a classical particle while its electrostatic field behaves as a wave phenomenon. As such an electron under Coulomb force moves strictly in accordance with Newtonian laws of motion. In this paper, we develop dynamic electron orbits in hydrogen atom by using energy and angular momentum conservation principle in central force field. We have shown that during photon emission, angular momentum of the orbiting electron is changed by ħ due to recoil action. This may be the origin of various quantization rules. During emission of a photon, elliptical orbit transitions are also computed and plotted. Orbit transition time is of the order of 10<sup>-16</sup> seconds. We have extended this methodology to compute electron orbits in hydrogen molecular bond and computed the H<sub>2</sub> bond energy. 展开更多
关键词 Sommerfeld Model Schrödinger Equation DYNAMIC Electron orbits Photon Emission
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Spherical and Circular Non-Equatorial Photon Orbits around Kerr Black Holes
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作者 Leo Morgovsky 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期888-896,共9页
By analytically solving the equation of azimuthal null geodesics for spherical photon trajectories, a parametric representation of the corresponding segment of the orbit is obtained. The solution parameter is the lati... By analytically solving the equation of azimuthal null geodesics for spherical photon trajectories, a parametric representation of the corresponding segment of the orbit is obtained. The solution parameter is the latitude coordinate. The dependences of the orbital radius on the black hole spinning parameter and the angle of inclination of its plane with respect to the rotation axis are calculated for flat circular non-equatorial orbits. It is proved that all spherical photon trajectories in the Kerr spacetime are unstable, as well as equatorial ones, and the critical photon orbits in the Schwarzschild metric. 展开更多
关键词 Black Holes Kerr Metric Photon Trajectories Null Geodesics orbits Instability
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Orbital-Ordering Driven Simultaneous Tunability of Magnetism and Electric Polarization in Strained Monolayer VCl_(3)
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作者 郭的坪 王聪 +4 位作者 王侣锦 陆赟豪 吴骅 张妍宁 季威 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第4期126-131,共6页
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
关键词 MONOLAYER symmetry orbitAL
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Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review
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作者 Farzad Pakdel Hassan Asadigandomani +5 位作者 Melika Arab Bafrani Zohreh Nozarian Zohre Abedinifar Niloofar Pirmarzdashti Behzad Jafari Zaynab Siami 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期603-606,共4页
Citation:Pakdel F,Asadigandomani H,Arab Bafrani M,Nozarian Z,Abedinifar Z,Pirmarzdashti N,Jafari B,Siami Z.Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review.Int J O... Citation:Pakdel F,Asadigandomani H,Arab Bafrani M,Nozarian Z,Abedinifar Z,Pirmarzdashti N,Jafari B,Siami Z.Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review.Int J Ophthalmol 2024;17(3):603-606. 展开更多
关键词 GRAFT orbitAL AFTER
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Theory for Charge Density Wave and Orbital-Flux State in Antiferromagnetic Kagome Metal FeGe
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作者 马海洋 殷嘉鑫 +1 位作者 M.Zahid Hasan 刘健鹏 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第4期90-104,共15页
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
关键词 interaction PHONON orbitAL
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Prognostic factors and clinical features of rhino-orbitalmucormycosis cases:an update for patient and visual survivals
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作者 Mustafa Aksoy Altan Atakan Ozcan Burak Ulas 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期916-923,共8页
AIM:To determine the frequency of patients’vision survival and prognostic factors and evaluate clinical features in rhino-orbital mucormycosis.METHODS:Forty-three eyes of 43 patients followed up with orbital mucormyc... AIM:To determine the frequency of patients’vision survival and prognostic factors and evaluate clinical features in rhino-orbital mucormycosis.METHODS:Forty-three eyes of 43 patients followed up with orbital mucormycosis infections were included in the study.Demographic characteristics of the patients,symptoms at admission,ophthalmologic and non-ophthalmologic examination findings,clinical findings during follow-up,medical and surgical procedures,and complications were recorded.Patient survival was determined by assessing the incidence of mortality,and vision survival was defined as achieving a final visual acuity of at least light perception.RESULTS:Twenty-seven(62.8%)patients were male,and 16(37.2%)were female.When the underlying disease status of the patients was examined,it was observed that all patients had an underlying disease and diabetes constituted the majority(65.2%).Periorbital swelling(69.8%)and ophthalmoplegia(53.5%)were the most common symptoms and findings at the admission of patients with mucormycosis infection.The disease resulted in death in 22(51.2%)patients.The presence of fever and shorter duration of antifungal therapy were associated with lower patient survival.Exenteration surgery was not found to be associated with the survival of the patients.Frozen eye,loss of pupillary light reflex,and development of central retinal artery occlusion were associated with lower vision survival.CONCLUSION:This study presents one of the most extensive patient series in the literature on rhino-orbital mucormycosis.Knowing the patients’symptoms at the time of admission and the clinical findings during the infection process will increase awareness about the disease. 展开更多
关键词 MUCORMYCOSIS rhino-orbital-mucormycosis orbital apex syndrome retinal arterial occlusion
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Effect of navigation endoscopy combined with threedimensional printing technology in the treatment of orbital blowout fractures
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作者 Jin-Hai Yu Yao-Hua Wang +3 位作者 Qi-Hua Xu Chao Xiong An-An Wang Hong-Fei Liao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期570-576,共7页
●AIM:To explore the combined application of surgical navigation nasal endoscopy(NNE)and three-dimensional printing technology(3DPT)for the adjunctive treatment of orbital blowout fractures(OBF).●METHODS:Retrospectiv... ●AIM:To explore the combined application of surgical navigation nasal endoscopy(NNE)and three-dimensional printing technology(3DPT)for the adjunctive treatment of orbital blowout fractures(OBF).●METHODS:Retrospective analysis was conducted on the data of patients with OBF who underwent surgical treatment at the Affiliated Eye Hospital of Nanchang University between July 2012 and November 2022.The control group consisted of patients who received traditional surgical treatment(n=43),while the new surgical group(n=52)consisted of patients who received NNE with 3DPT.The difference in therapeutic effects between the two groups was evaluated by comparing the duration of the operation,best corrected visual acuity(BCVA),enophthalmos difference,recovery rate of eye movement disorder,recovery rate of diplopia,and incidence of postoperative complications.●RESULTS:The study included 95 cases(95 eyes),with 63 men and 32 women.The patients’age ranged from 5 to 67y(35.21±15.75y).The new surgical group and the control group exhibited no statistically significant differences in the duration of the operation,BCVA and enophthalmos difference.The recovery rates of diplopia in the new surgical group were significantly higher than those in the control group at 1mo[OR=0.03,95%CI(0.01–0.15),P<0.0000]and 3mo[OR=0.11,95%CI(0.03–0.36),P<0.0000]postoperation.Additionally,the recovery rates of eye movement disorders at 1 and 3mo after surgery were OR=0.08,95%CI(0.03–0.24),P<0.0000;and OR=0.01,95%CI(0.00–0.18),P<0.0000.The incidence of postoperative complications was lower in the new surgical group compared to the control group[OR=4.86,95%CI(0.95–24.78),P<0.05].●CONCLUSION:The combination of NNE and 3DPT can shorten the recovery time of diplopia and eye movement disorder in patients with OBF. 展开更多
关键词 orbital blowout fracture three-dimensional printing ENDOSCOPY surgical navigation
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Generation of orbital angular momentum hologram using a modified U-net
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作者 郑志刚 韩菲菲 +1 位作者 王乐 赵生妹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期401-407,共7页
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
关键词 orbital angular momentum(OAM) HOLOGRAPHY OAM holography deep learning
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Manipulating d-d orbital hybridization induced by Mo-doped Co_(9)S_(8) nanorod arrays for high-efficiency water electrolysis
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作者 Xue Zhou Jing Li +8 位作者 Guangyao Zhou Weiran Huang Yucan Zhang Jun Yang Huan Pang Mingyi Zhang Dongmei Sun Yawen Tang Lin Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期592-600,I0015,共10页
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
关键词 d-d orbital hybridization Transition metal sulfides Nanorods arrays Water electrolysis
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Bessel–Gaussian beam-based orbital angular momentum holography
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作者 季佳滢 郑志刚 +3 位作者 朱家龙 王乐 王新光 赵生妹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期407-413,共7页
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
关键词 orbital angular momentum HOLOGRAPHY Bessel–Gaussian beam OAM-multiplexing hologram
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A Population Dynamics Approach to the Distribution of Space Debris in Low Earth Orbit
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作者 John Jurkiewicz Peter Hinow 《Communications on Applied Mathematics and Computation》 EI 2024年第1期340-353,共14页
The presence of the debris in the Earth’s orbit poses a significant risk to human activity in outer space.This debris population continues to grow due to ground launches,the loss of external parts from space ships,an... The presence of the debris in the Earth’s orbit poses a significant risk to human activity in outer space.This debris population continues to grow due to ground launches,the loss of external parts from space ships,and uncontrollable collisions between objects.A computationally feasible continuum model for the growth of the debris population and its spatial distribution is therefore critical.Here we propose a diffusion-collision model for the evolution of the debris density in the low-Earth orbit and its dependence on the ground-launch policy.We parametrize this model and test it against data from publicly available object catalogs to examine timescales for the uncontrolled growth.Finally,we consider sensible launch policies and cleanup strategies and how they reduce the future risk of collisions with active satellites or space ships. 展开更多
关键词 Population dynamics Space debris Kessler syndrome DIFFUSION Low-Earth orbit
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d-d Orbital coupling induced by crystal-phase engineering assists acetonitrile electroreduction to ethylamine
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作者 Honggang Huang Yao Chen +7 位作者 Hui Fu Cun Chen Hanjun Li Zhe Zhang Feili Lai Shuxing Bai Nan Zhang Tianxi Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期216-225,I0006,共11页
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
关键词 d-d orbital coupling Crystal-phase engineering Metallic aerogels Acetonitrile electroreduction reaction ETHYLAMINE
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Ab initio nonadiabatic molecular dynamics study on spin–orbit coupling induced spin dynamics in ferromagnetic metals
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作者 朱万松 郑镇法 +1 位作者 郑奇靖 赵瑾 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期156-163,共8页
Understanding the photoexcitation induced spin dynamics in ferromagnetic metals is important for the design of photo-controlled ultrafast spintronic device.In this work,by the ab initio nonadiabatic molecular dynamics... Understanding the photoexcitation induced spin dynamics in ferromagnetic metals is important for the design of photo-controlled ultrafast spintronic device.In this work,by the ab initio nonadiabatic molecular dynamics simulation,we have studied the spin dynamics induced by spin–orbit coupling(SOC)in Co and Fe using both spin-diabatic and spin-adiabatic representations.In Co system,it is found that the Fermi surface(E_(F))is predominantly contributed by the spin-minority states.The SOC induced spin flip will occur for the photo-excited spin-majority electrons as they relax to the E_(F),and the spin-minority electrons tend to relax to the EFwith the same spin through the electron–phonon coupling(EPC).The reduction of spin-majority electrons and the increase of spin-minority electrons lead to demagnetization of Co within100 fs.By contrast,in Fe system,the E_(F) is dominated by the spin-majority states.In this case,the SOC induced spin flip occurs for the photo-excited spin-minority electrons,which leads to a magnetization enhancement.If we move the E_(F) of Fe to higher energy by 0.6eV,the E_(F) will be contributed by the spin-minority states and the demagnetization will be observed again.This work provides a new perspective for understanding the SOC induced spin dynamics mechanism in magnetic metal systems. 展开更多
关键词 nonadiabatic molecular dynamics spin dynamics spin–orbit coupling ferromagnetic metal
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Asymmetric orbital hybridization in Zn-doped antiperovskite Cu_(1-x)Zn_(x)NMn_(3)enables highly efficient electrocatalytic hydrogen production
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作者 Yuxiang Yan Yuxin Cao +9 位作者 Zhichao Wang Ka Wang Hengdong Ren Shaoqi Zhang Yi Wang Jian Chen Yong Zhou Lizhe Liu Jun Dai Xinglong Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期304-312,I0008,共10页
Rational design of efficient and robust earth-abundant alkaline hydrogen evolution reaction(HER)catalysts is a key factor for developing energy conversion technologies.Currently,antiperovskite nitride CuNMn_(3)has gar... Rational design of efficient and robust earth-abundant alkaline hydrogen evolution reaction(HER)catalysts is a key factor for developing energy conversion technologies.Currently,antiperovskite nitride CuNMn_(3)has garnered significant interest due to its remarkable properties such as negative/zero thermal expansion and magnetocaloric effects.However,when utilized as hydrogen evolution catalysts,it encounters large challenge resulting from excessively strong/weak interactions with adsorbed H on Mn/Cu active sites,which leads to low HER activity.In this study,we introduce an asymmetric orbital hybridization strategy in Zn-doped Cu_(1-x)Zn_(x)NMn_(3)by leveraging the localization of Zn electronic states to reconfigure the electronic structures of Cu and Mn,thereby reducing the energy barrier for water dissociation and optimizing Cu and Mn active sites for hydrogen adsorption and H_(2)production.Electrochemical evaluations reveal that Cu_(0.85)Zn_(0.15)NMn_(3)with x=0.15 demonstrates exceptional electrocatalytic activity in alkaline electrolytes.A low overpotential of 52 mV at 10 mA cm^(-2)and outstanding stability over a 150-h test period are achieved,surpassing commercial Pt/C.This research offers a novel strategy for enhancing HER performance by modulating asymmetric hybridization of electron orbitals between multiple metal atoms within a material structure. 展开更多
关键词 Cu_(1-x)ZnxNMn_(3) Asymmetric orbital hybridization Hydrogen adsorption Hydrogen production
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Fast solution to the free return orbit's reachable domain of the manned lunar mission by deep neural network
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作者 YANG Luyi LI Haiyang +1 位作者 ZHANG Jin ZHU Yuehe 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期495-508,共14页
It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly eval... It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model. 展开更多
关键词 manned lunar mission free return orbit reachable domain(RD) deep neural network computation efficiency
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Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy
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作者 Zhengyan Du Zeshuo Meng +7 位作者 Haoteng Sun Yifan Li Chao Jiang Yaxin Li Xiaoying Hu Yi Cui Shansheng Yu Hongwei Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期52-62,共11页
Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction ... Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its role.To clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER process.Theoretical calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic species.The modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term durability.This study provides a novel perspective for understanding the role of Fe in the OER process. 展开更多
关键词 Oxygenevolution Fe_(5)Ni_(4)S_(8) Electronic orbital occupancy modulation Reconstruction dynamics
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Robust measurement of orbital angular momentum of a partially coherent vortex beam under amplitude and phase perturbations
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作者 Zhao Zhang Gaoyuan Li +5 位作者 Yonglei Liu Haiyun Wang Bernhard J.Hoenders Chunhao Liang Yangjian Cai Jun Zeng 《Opto-Electronic Science》 2024年第1期1-12,共12页
The ability to overcome the negative effects,induced by obstacles and turbulent atmosphere,is a core challenge of long-distance information transmission,and it is of great significance in free-space optical communicat... The ability to overcome the negative effects,induced by obstacles and turbulent atmosphere,is a core challenge of long-distance information transmission,and it is of great significance in free-space optical communication.The spatial-coherence structure,that characterizes partially coherent fields,provides a new degree of freedom for carrying information.However,due to the influence of the complex transmission environment,the spatial-coherence structure is severely damaged during the propagation path,which undoubtedly limits its ability to transmit information.Here,we realize the robust far-field orbital angular momentum(OAM)transmission and detection by modulating the spatial-coherence structure of a partially coherent vortex beam with the help of the cross-phase.The cross-phase enables the OAM information,quantified by the topological charge,hidden in the spatial-coherence structure can be stably transmitted to the far field and can resist the influence of obstructions and turbulence within the communication link.This is due to the self-reconstruction property of the spatial-coherence structure embedded with the cross-phase.We demonstrate experimentally that the topological charge information can be recognized well by measuring the spatial-coherence structure in the far field,exhibiting a set of distinct and separated dark rings even under amplitude and phase perturbations.Our findings open a door for robust optical signal transmission through the complex environment and may find application in optical communication through a turbulent atmosphere. 展开更多
关键词 degree of coherence orbital angular momentum cross-phase topological charge information transmission
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