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Implementation of Controlled Geometric Phase Gate for Two Trapped Neutral Atoms
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作者 吴怀志 杨贞标 郑仕标 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第11期835-839,共5页
We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use ... We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use theRydberg interaction induced energy shifts to generate geometric phase and construct quantum gates. 展开更多
关键词 neutral atom geometric phase gate Rydberg interaction
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First Neutral Atomic Hydrogen Images of Quasar Host Galaxies
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作者 Jeremy Lim (Academia Sinica Institute of Astronomy & Astrophysics PO Box 1 87, Nankang, Taipei 115, Taiwan) Paul T. P. Ho (Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA) 《天文研究与技术》 CSCD 1999年第S1期205-209,共5页
Violent galactic encounters or mergers are the leading contenders for triggering luminous quasar activity at low redshifts: such interactions can lead to the concentration of gas in the host galactic nucleus, thus fue... Violent galactic encounters or mergers are the leading contenders for triggering luminous quasar activity at low redshifts: such interactions can lead to the concentration of gas in the host galactic nucleus, thus fueling the suspected central superrmassive black hole. Although optical images show a number of violently interacting systems, in many cases the evidence for such interactions is only circumstantial (e.g., asymmetric optical morphologies, projected nearby companion galaxies) or not at all apparent. Here we image quasar host galaxies for the first time in the redshifted 21 cm line emission of neutral atomic hydrogen (HI) gas, which in nearby galaxies has proven to be a particularly sensitive as well as enduring tracer of tidal interactions. The three quasars studied have different optical environments normally seen around low reshift quasars, ranging from a perhaps mildly interacting system to a relatively undisturbed host with a projected neighbouring galaxy to an isolated and apparently serene host galaxy. By contrast with their optical appearences, all three quasar host galaxies exhibit ongoing or remnant tidal HI disruptions tracing galactic encounters or mergers. These observations provide a better understanding of the likely stage of their interaction. 展开更多
关键词 NATURE First neutral atomic Hydrogen Images of Quasar Host Galaxies
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Report on Science Project for Probing the High-Latitude Ionosphere with Complementary Radar and Energetic Neutral Atom(ENA)Measurements
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作者 Daniel Martini Carl-Fredrik Enell +2 位作者 Anita Aiko Thomas Ulich Young-Sil Kwak 《International Journal of Geosciences》 2014年第6期607-610,共4页
Vast magnetospheric regions are mapped along the field lines to the narrow latitudinal band of the polar/auroral regions. Therefore monitoring of solar wind energy dissipation into the ionosphere at auroral latitudes ... Vast magnetospheric regions are mapped along the field lines to the narrow latitudinal band of the polar/auroral regions. Therefore monitoring of solar wind energy dissipation into the ionosphere at auroral latitudes gives unique opportunities to study geomagnetic disturbances in their complexity from a relatively well-localized vantage point. Here we introduce and present the current state of a recently proposed science project for coordinated monitoring of high-latitude activity with the EISCAT (European Incoherent Scatter) radar array supported by ground-based magnetometer and optical data and ENA (Energetic Neutral Atom) observation from the CINEMA (Cube-Sat for Ions, Neutrals, Electrons and Magnetic field) satellite system. 展开更多
关键词 Energetic neutral atoms Incoherent Scatter Radar Satellite Observation Ionsphere Geomagnetic Activity
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Quantum states of neutral atoms bound in the magnetic field of a Kepler-guide
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作者 HE Ming, WANG Jin, ZHAN Ming sheng (State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P.R.China) 《原子与分子物理学报》 CAS CSCD 北大核心 2003年第3期369-372,共4页
The spectrum and the wave function of neutral atoms in the magnetic field of a Kepler guide are presented by reducing a two dimensional stationary Schrdinger equation to a one dimensional hydrogen atom in Rydberg st... The spectrum and the wave function of neutral atoms in the magnetic field of a Kepler guide are presented by reducing a two dimensional stationary Schrdinger equation to a one dimensional hydrogen atom in Rydberg states. In addition, we set the scale for the atomic orbits and binding energy in the quantum regime, and compare it with the outcome of the experiment. At the same time, we find that reducing the current and radius of the wire properly will increase the loading efficiency of the Kepler guide. 展开更多
关键词 量子态 中性原子 开普勒波导 磁性
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Rydberg quantum computation with nuclear spins in two-electron neutral atoms 被引量:4
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作者 Xiao-Feng Shi 《Frontiers of physics》 SCIE CSCD 2021年第5期21-38,共18页
Alkaline-earth-like(AEL)atoms with two valence electrons and a nonzero nuclear spin can be excited to Rydberg state for quantum computing.Typical AEL ground states possess no hyperfine splitting,but unfortunately a GH... Alkaline-earth-like(AEL)atoms with two valence electrons and a nonzero nuclear spin can be excited to Rydberg state for quantum computing.Typical AEL ground states possess no hyperfine splitting,but unfortunately a GHz-scale splitting seems necessary for Rydberg excitation.Though strong magnetic fields can induce a GHz-scale splitting,weak fields are desirable to avoid noise in experiments.Here,we provide two solutions to this outstanding challenge with realistic data of well-studied AEL isotopes.In the first theory,the two nuclear spin qubit states∣0〉and∣1〉are excited to Rydberg states∣r〉with detuningΔand 0,respectively,where a MHz-scale detuningΔarises from a weak magnetic field on the order of 1 G.With a proper ratio betweenΔandΩ,the qubit state∣1〉can be fully excited to the Rydberg state while∣0〉remains there.In the second theory,we show that by choosing appropriate intermediate states a two-photon Rydberg excitation can proceed with only one nuclear spin qubit state.The second theory is applicable whatever the magnitude of the magnetic field is.These theories bring a versatile means for quantum computation by combining the broad applicability of Rydberg blockade and the incomparable advantages of nuclear-spin quantum memory in two-electron neutral atoms. 展开更多
关键词 alkaline-earth atom Rydberg state quantum computation neutral atom
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Iterative inversion of global magnetospheric information from energy neutral atom (ENA) images recorded by the TC-2/NUADU instrument 被引量:6
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作者 S. MCKENNA-LAWLOR S. BARABASH J. BALAZ 《Science China(Technological Sciences)》 SCIE EI CAS 2008年第10期1731-1744,共14页
A method is presented for retrieving the magnetospheric ion distribution from En-ergetic Neutral Atom (ENA) measurements made by the NUADU instrument on the TC-2 spacecraft. Based on the already well-established metho... A method is presented for retrieving the magnetospheric ion distribution from En-ergetic Neutral Atom (ENA) measurements made by the NUADU instrument on the TC-2 spacecraft. Based on the already well-established method of constrained lin-ear inversion, an iterance technique suitable for the low count ENA measurements has been developed which is tolerant of the noise background. By the iterance technique, it is possible for the first time to simultaneously retrieve the magneto-spheric ion distribution and the exospheric neutral density, and further to recover global ENA emissions in three dimensions. The technique is applied to a repre-sentative ENA image recorded in energy channel 2 (protons: 50―81 keV) of the NUADU instrument during a major geomagnetic storm and it is, thereby, shown that the retrieval method developed provides a useful tool for extracting ion distribution information from ENA data. 展开更多
关键词 ENERGETIC neutral atom (ENA) ring current magnetospheric IONS exospheric neutral density
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A Single Folded Beam Magneto-Optical Trap System for Neutral Mercury Atoms 被引量:1
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作者 刘亢亢 赵儒臣 +6 位作者 苟维 付小虎 刘洪力 尹士奇 孙剑芳 徐震 王育竹 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第7期38-41,共4页
Mercury is a promising candidate for the optical lattice clock, due to its low sensitivity to the blackbody radiation. We develop a single folded beam magneto-optical trap for the neutral mercury optical lattice clock... Mercury is a promising candidate for the optical lattice clock, due to its low sensitivity to the blackbody radiation. We develop a single folded beam magneto-optical trap for the neutral mercury optical lattice clock, with a 253. 7nm frequency quadrupled laser. Up to 1.7 × 10^6 (202Hg) or 1.5 × 10^6 (199Hg) atoms can be captured, and the atom temperature is lowered to 170μK (202Hg) or 50μK (199Hg). The cold atom signals of all six rich abundant isotopes are observed in this system. 展开更多
关键词 for of Hg A Single Folded Beam Magneto-Optical Trap System for neutral Mercury atoms in is MOT
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Magneto optical trap for neutral mercury atoms
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作者 刘洪力 尹士奇 +4 位作者 刘亢亢 钱军 徐震 洪涛 王育竹 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期32-35,共4页
Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap (MOT... Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap (MOT). Because of the high vapor pressure at room temperature, the mercury source and the cold pump were cooled down to 40℃ and 70 ℃, respectively, to keep the science chamber in an ultra-high vacuum of 6×10^-9 Pa. Limited by the power of the UV cooling laser, the one beam folded MOT configuration was adopted, and 1.5×10^5 Hg-202 atoms were observed by fluorescence detection. 展开更多
关键词 laser cooling and trapping neutral mercury atom laser spectroscopy
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日球层边际能量中性原子遥感探测技术与发展趋势
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作者 于航 张嵬 +6 位作者 陆希 张伟 何建森 邹鸿 叶雨光 王永福 施伟红 《空间科学与试验学报》 CSCD 2024年第2期61-67,共7页
来自太阳系边际及以外的星际空间的能量中性原子,是认识邻近星际介质及其与太阳风相互作用的重要载体。受限于太阳系边际就位探测的任务时长与探测难度,在近地空间对日球层边际能量中性原子实施遥感探测更为切实可行。研究日球层边际能... 来自太阳系边际及以外的星际空间的能量中性原子,是认识邻近星际介质及其与太阳风相互作用的重要载体。受限于太阳系边际就位探测的任务时长与探测难度,在近地空间对日球层边际能量中性原子实施遥感探测更为切实可行。研究日球层边际能量中性原子可以增进对局地/邻近星际介质的组成及性质了解,深入验证太阳系演化与系内行星演变过程等空间科学问题,对推动我国空间任务和前沿科学发展有着重大意义。本文对近年来国际上开展或计划开展的日球层边际能量中性原子遥感探测的案例进行了总结,分析其探测任务的关键技术与科学目标,梳理了未来该领域的发展趋势及方向,针对我国今后的太阳系边际探测任务规划与技术发展提出了建议。 展开更多
关键词 日球层 能量中性原子 太阳系边际 遥感探测 星际介质
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Mars Ion and Neutral Particle Analyzer (MINPA) for Chinese Mars Exploration Mission (Tianwen-1): Design and ground calibration 被引量:7
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作者 LingGao Kong AiBing Zhang +15 位作者 Zhen Tian XiangZhi Zheng WenJing Wang Bin Liu Peter Wurz Daniele Piazza Adrian Etter Bin Su YaYa An JianJing Ding WenYa Li Yong Liu Lei Li YiRen Li Xu Tan YueQiang Sun 《Earth and Planetary Physics》 CSCD 2020年第4期333-344,共12页
The main objective of the Mars Ion and Neutral Particle Analyzer(MINPA)aboard the Chinese Mars Exploration Mission(Tianwen-1)is to study the solar wind-Mars interaction by measuring the ions and energetic neutral atom... The main objective of the Mars Ion and Neutral Particle Analyzer(MINPA)aboard the Chinese Mars Exploration Mission(Tianwen-1)is to study the solar wind-Mars interaction by measuring the ions and energetic neutral atoms(ENAs)near Mars.The MINPA integrates ion and ENA measurements into one sensor head,sharing the same electronics box.The MINPA utilizes a standard toroidal top-hat electrostatic analyzer(ESA)followed by a time of flight(TOF)unit to provide measurement of ions with energies from 2.8 eV to 25.9 keV and ENAs from 50 eV to 3 keV with a base time resolution of 4 seconds.Highly polished silicon single crystal substrates with an Al2O3 film coating are used to ionize the ENAs into positive ions.These ions can then be analyzed by the ESA and TOF,to determine the energy and masses of the ENAs.The MINPA provides a 360°×90°field of view(FOV)with 22.5°×5.4°angular resolution for ion measurement,and a 360°×9.7°FOV with 22.5°×9.7°angular resolution for ENA measurement.The TOF unit combines a-15 kV acceleration high voltage with ultra-thin carbon foils to resolve H+,He2+,He+,O+,O2+and CO2+for ion measurement and to resolve H and O(≥16 amu group)for ENA measurement.Here we present the design principle and describe our ground calibration of the MINPA. 展开更多
关键词 MARS ION energetic neutral atom electrostatic analyzer time of flight
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Controllable Magnetic Focusing of Cold Atoms on a Chip
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作者 刘泱 恽旻 印建平 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第7期1698-1701,共4页
We propose a new lens scheme to focus cold atoms by using a controllable inhomogeneous magnetic field from a square current-carrying wire fabricated on a chip. The spatial distributions of the magnetic field are calcu... We propose a new lens scheme to focus cold atoms by using a controllable inhomogeneous magnetic field from a square current-carrying wire fabricated on a chip. The spatial distributions of the magnetic field are calculated, and the results show that the generated magnetic field is a two-dimensional (2D) quadrupole one and can be used to focus cold atoms or a cold atomic beam. The dynamic processes of cold atoms passing through our square wire layout and its focusing properties are studied by using Monte Carlo simulations. Our study shows that the atomic clouds can be focused effectively by our magnetic lens scheme, and the focal length of the atomic lens and its radius of focused spot can be continuously changed by adjusting the current in the wires. 展开更多
关键词 BOSE-EINSTEIN CONDENSATION neutral atomS HOLLOW-BEAM LIGHT MICROMANIPULATION FORCES MIRROR OPTICS FUNNEL TRAPS
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Localization of a Three-Level Cascade Atom via Resonant Absorption
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作者 沈文炳 徐俊 胡响明 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第9期2583-2586,共4页
We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the... We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the detecting probability is 50% in the subwavelength domain, and the peaks are narrower on the resonance than the off- resonance. The absorption is the same as that in the usual two-level medium at the nodes and is greatly suppressed outside the nodes due to the Autler-Townes splitting. This is in sharp contrast to the lambda scheme, in which the localization is impossible under the same resonance condition due to the depletion of population of the initial state by the probe field at the nodes and the electromagnetically induced transparency outside the nodes. 展开更多
关键词 BOSE-EINSTEIN CONDENSATION QUANTUM NONDEMOLITION MEASUREMENT AUTLER-TOWNESMICROSCOPY POSITION MEASUREMENT neutral atomS PHASE-CONTROL SINGLE-atom DIFFRACTION INTERFERENCE SPECTRUM
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Quantum state swap for two trapped Rydberg atoms
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作者 吴怀志 杨贞标 郑仕标 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第4期82-87,共6页
The quantum swap gate is one of the most useful gates for quantum computation. Two-qubit entanglement and a controlled-NOT quantum gate in a neutral Rydberg atom system have been achieved in recent experiments. It is ... The quantum swap gate is one of the most useful gates for quantum computation. Two-qubit entanglement and a controlled-NOT quantum gate in a neutral Rydberg atom system have been achieved in recent experiments. It is therefore very interesting to propose a scheme here for swapping a quantum state between two trapped neutral atoms via the Rydberg blockade mechanism. The atoms interact with a sequence of laser pulses without individual addressing. The errors of the swap gate due to imprecision of pulse length, finite Rydberg interaction, and atomic spontaneous emission are discussed. 展开更多
关键词 neutral atom swap gate Rydberg blockade
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馄饨结构的KB@Co-C_(3)N_(4)在中性电解质中作为锌空气电池的高活性和稳定性氧催化剂
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作者 吴维凡 范晋歌 +4 位作者 赵振宏 潘建敏 杨静 阎兴斌 詹怡 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第5期178-189,共12页
金属和氮共掺杂碳(M-N-Cs)由于具有高原子利用率、良好的活性和选择性,因而被认为是具有潜力的氧电催化剂.但其热力学氧化势较低,碳材料在高电位下容易腐蚀.在放电过程中,锌空气电池正极的电位始终比碳氧化的热力学电位高约0.5 V,这导... 金属和氮共掺杂碳(M-N-Cs)由于具有高原子利用率、良好的活性和选择性,因而被认为是具有潜力的氧电催化剂.但其热力学氧化势较低,碳材料在高电位下容易腐蚀.在放电过程中,锌空气电池正极的电位始终比碳氧化的热力学电位高约0.5 V,这导致阴极中碳的严重腐蚀.对于M-N-C,腐蚀会破坏金属氮配位(M-Nx)活性位点,导致活性比表面积减少,同时还会改变孔隙形貌和表面特性,进而降低其催化活性.在充电(即氧气析出反应,OER)过程中,这种腐蚀现象会进一步加剧.因此,开发一种既具有高效双功能催化活性,又具有良好抗电化学腐蚀性能的M-N-C催化剂,对于解决上述问题至关重要.本文利用氮化碳(g-C_(3)N_(4))支撑钴氮配位(Co-Nx)活性位点,同时包覆科琴黑(KB)形成馄饨结构,制备了双功能氧催化剂KB@Co-C_(3)N_(4).首先,将剥离的C_(3)N_(4)与KB混合后煅烧,得到C_(3)N_(4)包覆的KB材料(KB@C_(3)N_(4));随后,再次煅烧将Co单原子引入KB@C_(3)N_(4)中,形成具有高活性和高稳定性的KB@Co-C_(3)N_(4)氧催化剂.红外光谱结果证实了,KB@Co-C_(3)N_(4)中存在C_(3)N_(4)成分.透射电镜和元素标记结果表明,C_(3)N_(4)均匀包覆在KB基底上.同步辐射测试确定了Co单原子的配位环境为CoN4结构.在0.5 mol L^(-1) NH_(4)Cl溶液中测试了KB@Co-C_(3)N_(4)氧催化剂ORR/OER的催化活性和稳定性.结果表明,KB@CoC_(3)N_(4)表现出较好的ORR性能,半波电位为0.723 V,显著优于商业铂碳催化剂(0.673 V)和普通Co-N-C催化剂(0.694 V).经过40000圈加速耐久性测试,KB@Co-C_(3)N_(4)仅衰减9 mV,而商业铂碳和Co-N-C在7500圈测试后分别衰减41和44 mV.在OER方面,KB@Co-C_(3)N_(4)在10 mA cm^(-2)时的过电位为550 mV,优于氧化钌的560 mV和Co-N-C的600 mV.经过20000圈测试,KB@Co-C_(3)N_(4)的OER过电位几乎保持不变,而氧化钌和Co-N-C经过4000圈测试后分别增加了37和20 mV.透射电镜观察发现,KB@Co-C_(3)N_(4)在实验前后形貌未发生明显变化,证明了其较好的稳定性.理论计算揭示,C_(3)N_(4)能够优化Co金属活性位点的电子结构,改善Co中心的电荷分布并增强Co-N键强度;同时,C_(3)N_(4)对KB基底的包覆有效避免了KB在高电位下的腐蚀,确保了KB@Co-C_(3)N_(4)的高稳定性和催化活性.将KB@Co-C_(3)N_(4)应用于中性锌空气电池中,该电池展现出1.52 V的开路电压,并在5 mA cm^(-2)的高电流密度下稳定循环运行超过985 h,性能优于大多数报道的采用碳基材料作为阴极催化剂的中性锌空气电池.综上所述,馄饨结构的KB@Co-C_(3)N_(4)具有较好的氧催化活性和稳定性,为设计高稳定性高活性的M-N-C催化剂提供了一定的参考. 展开更多
关键词 氧电催化 单原子催化剂 中性电解液 抗腐蚀
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Neutralized solar energetic particles for SEP forecasting:Feasibility study of an innovative technique for space weather applications
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作者 Xiao-Dong Wang B.Klecker +6 位作者 G.Nicolaou S.Barabash M.Wieser P.Wurz A.Galli F.Cipriani Y.Futaana 《Earth and Planetary Physics》 CSCD 2022年第1期42-51,共10页
Energetic neutral atoms(ENAs)are produced by the neutralization of energetic ions formed by shock-accelerated gradual solar energetic particle events(SEP).These high-energy ENAs(HENAs)can reach the Earth earlier than ... Energetic neutral atoms(ENAs)are produced by the neutralization of energetic ions formed by shock-accelerated gradual solar energetic particle events(SEP).These high-energy ENAs(HENAs)can reach the Earth earlier than the associated SEPs and thus can provide information about the SEPs at the lower corona.The HENA properties observed at Earth depend on the properties of the coronal mass ejection(CME)-driven shocks that accelerate the SEPs.Using a model of HENA production in a shock-accelerated SEP event,we semi-quantitatively investigate the energy-time spectrum of HENAs depending on the width,propagation speed,and direction of the shock,as well as the density and ion abundances of the lower corona.Compared to the baseline model parameters,the cases with a wider shock width angle or a higher coronal density would increase the HENA flux observed at the Earth,while the case with an Earthpropagating shock shows a softened HENA spectrum.The comparison of expected HENA fluxes in different cases with a flight-proven ENA instrument suggests that solar HENAs can feasibly be monitored with current technologies,which could provide a lead time of 2−3 hours for SEPs at a few MeV.We propose that monitoring of solar HENAs could provide a new method to forecast shock-driven SEP events that are capable of significant space weather impacts on the near-Earth environment. 展开更多
关键词 solar energetic particles energetic neutral atoms space weather numerical simulation
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3d过渡金属单原子掺杂石墨烯缺陷电催化还原CO_(2)的第一性原理研究
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作者 靳宇翔 宋二红 朱永福 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2024年第7期845-852,I0012-I0014,共11页
将CO_(2)高效转化为有价值的化学品(如CO和HCOOH等)是缓解环境问题、实现碳中和的重要措施。然而CO_(2)还原反应(CO_(2)RR)有着产物多样和路径复杂的特点,再加上目前难以确定影响CO_(2)RR活性的真正因素,使得设计对特定产物有高选择性... 将CO_(2)高效转化为有价值的化学品(如CO和HCOOH等)是缓解环境问题、实现碳中和的重要措施。然而CO_(2)还原反应(CO_(2)RR)有着产物多样和路径复杂的特点,再加上目前难以确定影响CO_(2)RR活性的真正因素,使得设计对特定产物有高选择性和高活性的催化剂十分具有挑战性。本研究从第一性原理出发,系统研究了3d过渡金属单原子掺杂石墨烯单个空位(TM@CSV)和双空位(TM@CDV)电催化还原CO_(2)的潜力,具体涵盖基底的稳定性、中间产物热力学吸附以及与之竞争的析氢反应(HER)。通过对Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu和Zn掺杂石墨烯缺陷后形成的20种催化剂进行筛选,发现Sc原子掺杂石墨烯单个空位的Sc@CSV和Sc、Ti原子掺杂石墨烯双空位的Sc@CDV和Ti@CDV同时具备吸附CO_(2)分子和抑制HER的能力。其中Sc@CDV对HCOOH表现出最佳的活性和选择性,速率决定步骤的吉布斯自由能差仅为0.96 eV。最后,通过电子结构分析进一步揭示了Sc@CDV优于其他催化剂的原因是Sc@CDV调整了费米能级附近的活性电子态,从而实现对CO_(2)的高效还原。 展开更多
关键词 第一性原理 单原子催化剂 CO_(2)还原反应 HCOOH 碳中和
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Enhanced cold mercury atom production with two-dimensional magneto-optical trap 被引量:2
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作者 Ye Zhang Qi-Xin Liu +2 位作者 Jian-Fang Sun Zhen Xu Yu-Zhu Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第7期262-267,共6页
A cold atom source is important for quantum metrology and precision measurement.To reduce the quantum projection noise limit in optical lattice clock,one can increase the number of cold atoms and reduce the dead time ... A cold atom source is important for quantum metrology and precision measurement.To reduce the quantum projection noise limit in optical lattice clock,one can increase the number of cold atoms and reduce the dead time by enhancing the loading rate.In this work,we realize an enhanced cold mercury atom source based on a two-dimensional(2D)magnetooptical trap(MOT).The vacuum system is composed of two titanium chambers connected with a differential pumping tube.Two stable cooling laser systems are adopted for the 2D-MOT and the three-dimensional(3D)-MOT,respectively.Using an optimized 2D-MOT and push beam,about 1.3×10^(6)atoms,which are almost an order of magnitude higher than using a pure 3D-MOT,are loaded into the 3D-MOT for202Hg atoms.This enhanced cold mercury atom source is helpful in increasing the frequency stability of a neutral mercury lattice clock. 展开更多
关键词 magneto-optical trap atomic beam neutral mercury atom laser cooling and trapping
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New bipartition model of neutral particle transport in the HL-2A divertor region
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作者 DENGBai-quan YANJian-cheng PENGLi-lin 《核聚变与等离子体物理》 EI CAS CSCD 北大核心 2005年第2期139-145,共7页
A new bipartition neutral transport model has been developed for simulation of the hydrogenic neutral particle transport in the vicinity of HL-2A divertor target plate.The numerical calculation results on the basis of... A new bipartition neutral transport model has been developed for simulation of the hydrogenic neutral particle transport in the vicinity of HL-2A divertor target plate.The numerical calculation results on the basis of this model are fairly consistent with the results obtained with the "multi-generation method". One possible application of this model is to provide a source term originating from neutral transport calculation for any other edge plasma transport code, for instance, B-2 code, which has been used to simulate edge plasma transport of the HL-2A divertor configuration. Especially it can be utilized to quickly classify the plasma in divertor region as high or low recycling regime. 展开更多
关键词 中性粒子传输 氢原子 HL-2A托卡马克 计算机仿真
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抑制频率互调效应的阵列式光镊技术研究
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作者 王世珍 陈嘉怡 +2 位作者 李东豪 徐忠孝 申恒 《红外与激光工程》 EI CSCD 北大核心 2023年第7期166-172,共7页
由于TeO2声光偏转器(Acousto-optic deflector,AOD)具有超快的扫描速度、较宽的布拉格带宽以及大范围的偏转角度等优点,可以及时地改变光镊的位置,因此是获得无缺陷原子阵列的重要工具,在量子计算与模拟中具有重要的作用。但是,当声光... 由于TeO2声光偏转器(Acousto-optic deflector,AOD)具有超快的扫描速度、较宽的布拉格带宽以及大范围的偏转角度等优点,可以及时地改变光镊的位置,因此是获得无缺陷原子阵列的重要工具,在量子计算与模拟中具有重要的作用。但是,当声光偏转器输入含有多频率成分的信号时,会出现频率之间相互调制,导致衍射效率降低,出现不需要的衍射光且得到的衍射光强度分布不均匀等问题。基于此,对多个频率之间的相互调制过程进行了分析,通过对模型的计算分析得到了抑制频率互调的相位条件,并通过实验进行验证,再进行强度优化后得到强度分布相对均匀的光镊阵列。之后对互调过程进行仿真模拟,仿真结果显示与实验测量结果基本符合。对光镊阵列的参数测试显示,聚焦光镊的腰斑为1.5μm,现有实验光路可获得间距3μm的22×22的光镊阵列,满足中性原子阵列的实验需求。 展开更多
关键词 光镊阵列 声光偏转器 频率互调 中性原子阵列
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中性原子成像探测的物理设计与仿真 被引量:5
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作者 路立 S McKenna-Lawlor +3 位作者 J Balaz 史建魁 杨垂柏 罗静 《空间科学学报》 CAS CSCD 北大核心 2014年第3期341-351,共11页
研究了磁层-电离层-热层耦合星座(MIT)卫星计划中高能中性原子成像仪(NAIS-H)探测方案的原理设计和模拟仿真.以双星中性原子成像仪设计思想为基础,依据MIT卫星计划的总体科学目标和磁层卫星的轨道环境及相应自旋姿态,给出中性原子成像... 研究了磁层-电离层-热层耦合星座(MIT)卫星计划中高能中性原子成像仪(NAIS-H)探测方案的原理设计和模拟仿真.以双星中性原子成像仪设计思想为基础,依据MIT卫星计划的总体科学目标和磁层卫星的轨道环境及相应自旋姿态,给出中性原子成像仪的技术架构,并针对地磁偶极场的环电流模型进行了模拟仿真.仿真结果表明,所研制的NAIS-H以其高时空分辨能力适用于监测和反演磁暴期间磁层等离子体的全球动力学过程. 展开更多
关键词 能量中性原子 自旋姿态 环电流
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