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Galactic Haloes from Self-Interacting Neutrinos
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作者 Richard B. Holmes 《Journal of Modern Physics》 2020年第6期854-885,共32页
The objective of this research is to provide an explanation of galactic haloes using established particles and forces using recent theoretical developments. Light fermions, with masses on the order of 1 eV/c<sup>... The objective of this research is to provide an explanation of galactic haloes using established particles and forces using recent theoretical developments. Light fermions, with masses on the order of 1 eV/c<sup>2</sup>, are not a leading candidate for dark matter because of their large free-streaming scale length and their violation of the Tremaine-Gunn bound. With a self-interaction of fermions, the free-streaming scaling length is reduced, and the tenets of the Tremaine-Gunn bound are not applicable. Binding of neutrinos via a feeble SU(3) force is considered as a model for such interactions. The assumed sum of masses of the three neutrino flavors is 0.07 eV/c<sup>2</sup>. The resulting form of matter for such bound neutrinos is found to be a degenerate Fermi fluid. Pressure-equilibrium approaches applied to this fluid provide cuspy solutions and match observationally-inferred profiles for galactic haloes. Such approaches also match the observed total enclosed mass for galaxies similar to the Milky Way. The computed structures are found to be stable. The hypothesis is considered in view of observationally-inferred halo-halo interactions and gives results that are consistent with the observed Bullet cluster halo interaction. The theory gives agreement with observationally-inferred properties of dark matter near earth. Questions related to interaction rates, consistency with SN1987a data, the cosmic microwave background, the issue of SU(3) interactions between neutrinos and quarks, free-streaming after neutrino decoupling, and dark-matter abundance are addressed in a companion paper. 展开更多
关键词 Galactic haloes Dark Matter Halo-Halo Interactions
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Negative Haloes and Geochemical Field Systems of Hydrothermal Deposits 被引量:1
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作者 Ji Kejian, Wang Liben, Lu Fengxiang, Wang Wuyi and Zhang Jianhua Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1993年第2期195-209,共15页
Primary haloes of hydrothermal deposits were previously considered as positive haloes. Although it has been recently suggested that primary haloes incude positive and negative ones, almost all the research work on pri... Primary haloes of hydrothermal deposits were previously considered as positive haloes. Although it has been recently suggested that primary haloes incude positive and negative ones, almost all the research work on primary haloes has still focused on positive haloes for various reasons. In order to understand the source of ore substances a number of large hydrothermal deposits related to magmatism including porphyry, skarn and vein type deposits have been studied. It has been found that negative haloes exist on the peripheries of positive haloes of a mineral deposit. On the basis of the study the authors propose the concept of the geochemical field system of ore-forming elements of hydrotherreal deposits, i. e., with the orebody as the centre outwards there occur the mineralized field, positive halo field, depleted field and background field successively. 展开更多
关键词 hydrothermal deposit negative halo geochemical field system
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Subhalo Abundance and Satellite Spatial Distribution in Milky Way-Andromeda-like Paired Haloes
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作者 Kemeng Li Shi Shao +2 位作者 Ping He Qing Gu Jie Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第12期344-352,共9页
We study the subhalo and satellite populations in haloes similar to the Milky Way(MW)-Andromeda paired configuration in the Millennium II and P-Millennium simulations.We find subhaloes are 5%–15%more abundant in pair... We study the subhalo and satellite populations in haloes similar to the Milky Way(MW)-Andromeda paired configuration in the Millennium II and P-Millennium simulations.We find subhaloes are 5%–15%more abundant in paired haloes than their isolated counterparts that have the same halo mass and large-scale environmental density.Paired haloes tend to reside in a more isotropic environment than isolated haloes,the shear tensor of their large-scale tidal field is possibly responsible for this difference.We also study the thickness of the spatial distribution of the top 11 most massive satellite galaxies obtained in the semi-analytic galaxy sample constructed from the Millennium II simulation.Moreover,satellites that have lost their host subhaloes due to the resolution limit of the simulation have been taken into account.As a result,we find that the difference in the distribution of the satellite thickness between isolated and paired haloes is indistinguishable,which suggests that the paired configuration is not responsible for the observed plane of satellites in the MW.The results in this study indicate the paired configuration could bring some nonnegligible effect on the subhalo abundance in the investigation of the MW's satellite problems. 展开更多
关键词 galaxies:abundances galaxies:halos galaxies:structure (galaxies:)Local Group (cosmology:)dark matter methods:numerical
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基于弗洛凯特理论的Halo轨道辐轮构型编队控制设计
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作者 闫雪梅 杜博皓 +2 位作者 徐明 张锐 胡志强 《宇航学报》 EI CAS CSCD 北大核心 2024年第9期1408-1418,共11页
面向未来使用平动点航天器编队进行深空探测的需求,研究了特殊的定向辐轮构型航天器编队在日地L2平动点Halo轨道上的动力学和相关控制问题。首先,建立了圆型限制性三体问题(CRTBP)的相对动力学和辐轮构型编队模型的数学表达;其次,基于Fl... 面向未来使用平动点航天器编队进行深空探测的需求,研究了特殊的定向辐轮构型航天器编队在日地L2平动点Halo轨道上的动力学和相关控制问题。首先,建立了圆型限制性三体问题(CRTBP)的相对动力学和辐轮构型编队模型的数学表达;其次,基于Floquet理论和傅里叶级数展开推导了Halo轨道的相对运动解析解,该解的推导同样可应用于其他小偏离的周期时变系统;接着,以深空探测任务为导向,基于Floquet模态法和LQR控制法分别给出编队主星和从星的分层控制策略;最后,对控制策略进行仿真,详细分析了辐轮构型维持控制力的规律等,得到了构型参数(半径和频率)与维持代价的关系。 展开更多
关键词 深空探测 HALO轨道 编队控制 Floquet模态法 解析解
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地月周期轨道对地月L1与L2附近Halo轨道的可见性分析
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作者 李星明 果琳丽 +3 位作者 伏瑞敏 郑国宪 王培培 董联庆 《航天返回与遥感》 CSCD 北大核心 2024年第2期53-65,共13页
随着去往月球航天器的增多,现有的近地空间光学卫星与地基光学望远镜的探测能力已无法满足要求,急需增强地月空间观测能力,通过使用地月周期轨道来填补地月空间观测能力的不足被认为是一种有效手段。针对地月周期轨道的特性,文章基于微... 随着去往月球航天器的增多,现有的近地空间光学卫星与地基光学望远镜的探测能力已无法满足要求,急需增强地月空间观测能力,通过使用地月周期轨道来填补地月空间观测能力的不足被认为是一种有效手段。针对地月周期轨道的特性,文章基于微分校正原理对三体轨道建模,并完成了算法的设计,提出了地月周期轨道的选择原则,并优选了3条轨道。在地月周期轨道对地月拉格朗日点L1、L2附近Halo轨道的可见性分析中,为方便评估,采用类球体的物体星等评估模型来定义可见性的评估标准;基于卫星工具包提供模型计算中涉及的自然天体、物体和观测卫星三者的时空关系,给出了可见性分析过程及结果,研究表明地月周期轨道对地月拉格朗日点L1、L2附近Halo轨道均有不错的观测效果,其中轨道1对地月周期轨道的可见性综合最高,均大于95%。 展开更多
关键词 地月周期轨道 微分校正 HALO轨道 星等模型 可见性 空间探测
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最佳Halo重力牵引治疗Lenke3型脊柱侧凸的生物力学分析 被引量:1
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作者 富荣昌 杨骁峥 李现政 《中国组织工程研究》 CAS 北大核心 2024年第18期2901-2905,共5页
背景:Halo重力牵引是许多学者认可的术前牵引方法,但大部分为临床观察,缺乏有限元的相关分析。目的:运用有限元法探究Halo重力牵引对Lenke3型脊柱侧凸的最佳牵引力,从生物力学角度为临床提供理论依据。方法:对脊柱侧凸患者扫描的CT图像... 背景:Halo重力牵引是许多学者认可的术前牵引方法,但大部分为临床观察,缺乏有限元的相关分析。目的:运用有限元法探究Halo重力牵引对Lenke3型脊柱侧凸的最佳牵引力,从生物力学角度为临床提供理论依据。方法:对脊柱侧凸患者扫描的CT图像进行逆向建模处理并建立有限元模型,并取正常节段(T1-T4椎体)对模型的有效性进行验证。对腰胸椎侧凸模型设置5组不同的受力条件,模拟患者在不同牵引力作用下的矫正情况。5组皆将L5下表面完全约束,在T1上表面施加沿Z轴正方向(重力的反方向)不同大小的牵引力,分别为50,100,150,200,250 N。对比不同牵引力下侧凸脊柱的位移、主弯曲的Cobb角变化情况、脊柱的伸长量以及Von Mises应力。结果与结论:①当Halo重力牵引力为150-200 N时,主弯曲的Cobb角缩小量为最大缩小量的69.4%-88.9%,Z轴的伸长量是最大伸长量69.4%-85.9%,受到的应力为最大应力的63.6%-82.9%;②牵引力大于200 N,Cobb角的减少量和Z轴的伸长量变化不明显,但应力值急剧增长,且此时的T6、T7、T8椎体质心到L5中垂线的减小距离最为明显;③当Halo重力牵引力为150-200 N时,对此类型患者的矫正效果最佳——Cobb角缩小量与Z轴伸长量效果较佳的同时不会有应力的急剧增长。上述结果可为临床矫正提供一定的理论支持,可在较大程度矫正侧凸时保证患者安全。 展开更多
关键词 脊椎侧凸 Halo重力牵引 COBB角 有限元
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微流星体碰撞对日地L_(2)点Halo轨道的影响
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作者 李庆军 吴雨亭 +3 位作者 王博 霍卓玺 刘冀林 刘慧根 《动力学与控制学报》 2024年第6期16-23,共8页
空间中存在大量高速运动的微流星体,与在轨运行的航天器发生碰撞后将导致轨道偏离、性能下降、结构破坏甚至航天器失效.由于Halo轨道具有不稳定的特性,本文主要探究微流星体碰撞对日地L_(2)点Halo轨道动力学演化规律的影响.首先,建立日... 空间中存在大量高速运动的微流星体,与在轨运行的航天器发生碰撞后将导致轨道偏离、性能下降、结构破坏甚至航天器失效.由于Halo轨道具有不稳定的特性,本文主要探究微流星体碰撞对日地L_(2)点Halo轨道动力学演化规律的影响.首先,建立日地L_(2)点附近轨道的动力学模型,通过微分修正法构造Halo轨道的初始条件,基于Grün微流星体通量模型计算微流星体与航天器碰撞的数量和碰撞引起的速度改变量.然后,采用Runge-Kutta算法求解Halo轨道的动力学方程,研究碰撞速度改变量引起的轨道偏差随时间的演化规律.此外,采用状态转移矩阵方法分析初始状态偏差的演化规律,并与数值积分方法对比.最后基于状态转移矩阵方法分析了不同碰撞速度改变量的大小和方向引起的动力学响应.研究发现,状态转移矩阵在短时间内得到的结果与数值积分方法基本一致,而且只需一次矩阵乘法即可通过初始状态偏差计算得到末时刻状态偏差,具有非常高的效率.研究结果表明,由于Halo轨道固有的不稳定特性,所以初始时刻微流星体碰撞引起的微小状态偏差会快速增长,导致消耗更多控制燃料,最终将影响航天器的寿命.此外,微流星体碰撞的速度改变量的方向对偏差传递的规律有重要的影响. 展开更多
关键词 微流星体碰撞 HALO轨道 状态转移矩阵 太空望远镜
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改良Halo骨盆牵引对重度脊柱畸形伴呼吸功能障碍患者的干预效果
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作者 杨云飞 黄立军 +5 位作者 夏庆福 张玉双 赵国峰 夏纪元 田新奇 刘畅 《河北医药》 CAS 2024年第11期1642-1646,共5页
目的探讨一期改良Halo骨盆牵引(halo-pelvic traction,HPT)联合二期手术对重度脊柱畸形伴呼吸功能障碍患者的应用效果。方法选取2019年1月至2022年1月北京大望路急诊抢救医院收治的120例重度脊柱畸形伴呼吸功能障碍患者作为研究对象。... 目的探讨一期改良Halo骨盆牵引(halo-pelvic traction,HPT)联合二期手术对重度脊柱畸形伴呼吸功能障碍患者的应用效果。方法选取2019年1月至2022年1月北京大望路急诊抢救医院收治的120例重度脊柱畸形伴呼吸功能障碍患者作为研究对象。所有患者均行一期HPT牵引治疗和二期脊柱畸形矫形术。牵引前、牵引末次复查、内固定术后、末次随访,比较患者影像学指标和呼吸功能指标的变化情况。结果牵引前,患者主弯侧凸Cobb角、颈7铅垂线至骶骨正中线的距离(C7PL-CSVL)、顶椎偏距(AVT)、T1倾斜角、影像学肩高度、矢状面偏移(SVA)、腰胸椎后凸角(TK)为(119.17±15.39)°、(33.33±7.2)mm、(103.55±16.56)mm、(20.13±5.94)°、(26.78±6.32)mm、(38.29±5.54)mm、(87.66±11.63)°,高于牵引末次复查[(74.62±15.15)°、(13.23±4.27)mm、(57.70±17.56)mm、(9.29±1.73)°、(10.18±2.00)mm、(14.41±3.24)mm、(52.96±12.11)°]、内固定术后[(60.78±14.40)°、(12.42±3.58)mm、(44.31±13.77)mm、(8.89±2.66)°、(9.38±2.39)mm、(17.11±3.24)mm、(51.28±11.20)°]和末次随访[(64.21±14.86)°、(12.69±3.26)mm、(45.17±11.65)mm、(6.51±1.77)°、(9.53±2.36)mm、(17.50±3.07)mm、(51.82±12.20)°],差异有统计学意义(P<0.01)。牵引前,患者FVC、FVC%、FEV1、FEV1%为(1.13±0.19)L、(31.61±4.64)%、(1.08±0.22)L、(29.68±11.56)%,低于牵引末次复查[(1.36±0.28)L、(36.19±4.95)%、(1.17±0.19)L、(33.45±5.97)%]、内固定术后[(1.49±0.28)L、(38.08±7.46)%、(1.26±0.22)L、(35.91±7.81)%]和末次随访[(1.53±0.26)L、(38.61±6.91)%、(1.28±0.24)L、(36.88±7.85)%],差异有统计学意义(P<0.01)。结论改良HPT牵引能有效矫正重度脊柱畸形伴呼吸功能障碍患脊柱畸形,改善呼吸功能,是一种安全、有效地辅助治疗措施。 展开更多
关键词 Halo骨盆牵引 改良 呼吸功能障碍 重度脊柱畸形
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Halo-骨盆牵引治疗重度脊柱侧弯畸形的效果及其对肺功能的影响
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作者 夏纪元 杨云飞 +2 位作者 黄立军 夏庆福 张玉双 《武警医学》 CAS 2024年第3期230-234,共5页
目的探讨Halo-骨盆牵引(HPT)治疗重度脊柱侧弯畸形的效果及其对肺功能的影响。方法回顾性分析2021-01至2023-10北京大望路急诊抢救医院收治的100例脊柱侧弯合并肺功能不全患者的临床资料作为研究对象,所有患者均行一期HPT牵引治疗和二... 目的探讨Halo-骨盆牵引(HPT)治疗重度脊柱侧弯畸形的效果及其对肺功能的影响。方法回顾性分析2021-01至2023-10北京大望路急诊抢救医院收治的100例脊柱侧弯合并肺功能不全患者的临床资料作为研究对象,所有患者均行一期HPT牵引治疗和二期脊柱侧弯矫形术。牵引前、牵引末次复查、内固定术后,比较患者影像学指标和肺功能指标的变化情况。采用Pearson统计学相关性分析主弯Cobb角对肺功能指标的影响。结果纳入患者肺功能结果显示,牵引前、牵引末次复查、内固定术后比较,限制性通气功能参数均存在不同程度增高(P<0.05)。相关分析表明,随着主弯Cobb角减小,肺限制性通气功能参数呈显著负相关性(P<0.05)。结论HPT牵引能有效矫正重度脊柱侧弯畸形,改善呼吸功能,是一种安全、有效的辅助治疗措施。 展开更多
关键词 Halo骨盆牵引 肺功能不全 重度脊柱畸形
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Statistical Study of the Geoeffectivity of Halo Coronal Mass Ejections Associated with X-Class Flares during Solar Cycles 23 and 24
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作者 Younoussa Diakite Christian Zoundi +1 位作者 M’Bi Kabore Jean Louis Zerbo 《Open Journal of Applied Sciences》 2024年第4期950-960,共11页
By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ej... By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 December 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth. 展开更多
关键词 CME Halo (X) Geoeffectivity Geomagnetic Storm Solar Flare Solar Cycle
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Extinction of Light in the Galactic Halo: First Observational Evidence of the Interaction of Light and Dark Matter
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作者 Charles H. McGruder III 《Journal of Modern Physics》 2024年第8期1144-1198,共55页
We study the distribution of quasars on the celestial sphere according to ground-based SDSS and space-based WISE and Gaia observations. All distributions as a function of galactic latitude, b, exhibit a decrease in qu... We study the distribution of quasars on the celestial sphere according to ground-based SDSS and space-based WISE and Gaia observations. All distributions as a function of galactic latitude, b, exhibit a decrease in quasar frequency well outside the dust in and near the galactic plane. We prove that the observed decrease in quasar frequency at high galactic latitudes is not accompanied by reddening, meaning that it can not be caused by dust. The scattering of light by the circumgalactic gas is negligible because the Thomson scattering cross section is very small. We conclude the observed scattering of light must be caused by dark matter in the galactic halo. We determine the mass and charge of dark matter particles. If the dark matter particle is a fermion its mass, mDMand charge eDM=δe, where e is the elementary charge are: mDM=3.2×10−2eV and δ=3.856×10−5. If however the dark matter particle is spinless then: mDM=0.511eV and δ=2.132×10−4. These values for the charge of a dark matter particle are orders of magnitude higher than the upper limit of the neutrino charge according to laboratory experiments. Consequently, dark matter particles are not charged neutrinos. Since dark matter particles are charged, they must emit and absorb electromagnetic radiation. However, PDM~δ2, or: PDM~1.487×10−9Pe, where Peis the power output of a single electron. 展开更多
关键词 Milky Way Dark Matter Halo (1049)
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2022年国外高超声速空面导弹发展动态研究 被引量:2
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作者 任春艳 刘颖 +2 位作者 张迁 周江阳 史丹雅 《航空兵器》 CSCD 北大核心 2023年第6期18-26,共9页
对2022年国外高超声速空面导弹的发展动态进行了总结和归纳,包括Kh-47M“匕首”高超声速导弹、Kh-95远程高超声速导弹、“锐利”高超声速导弹、“幼虫”-MD高超声速武器系统、AGM-183A高超声速导弹、高超声速攻击巡航导弹(HACM)、高超... 对2022年国外高超声速空面导弹的发展动态进行了总结和归纳,包括Kh-47M“匕首”高超声速导弹、Kh-95远程高超声速导弹、“锐利”高超声速导弹、“幼虫”-MD高超声速武器系统、AGM-183A高超声速导弹、高超声速攻击巡航导弹(HACM)、高超声速空射进攻性反水面目标导弹(HALO)、“啸箭”(Screaming Arrow)导弹、“牌王”(Gambit)导弹和“高超声速飞行2”(HyFly2)导弹,并对2022年国外高超声速空面导弹的研发、试验及作战等特点进行了分析。 展开更多
关键词 高超声速空面导弹 Kh-47M“匕首”导弹 Kh-95导弹 “锐利”导弹 “幼虫”-MD导弹 AGM-183A导弹 HACM导弹 HALO导弹 “啸箭”导弹 “牌王”导弹 “高超声速飞行2”导弹
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利用halo导航星的地月空间联合自主轨道确定
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作者 刘磊 刘也 +1 位作者 程潏 刘勇 《宇航学报》 EI CAS CSCD 北大核心 2023年第8期1151-1159,共9页
面向未来地月空间的自主导航定位需求,研究了利用halo导航星的地月空间联合自主轨道确定(LAOD)。首先,建立了基于星间测距的地月空间联合自主定轨模型;其次,讨论了利用halo导航星联合自主定轨的可观性;最后,数值分析了不同误差条件下导... 面向未来地月空间的自主导航定位需求,研究了利用halo导航星的地月空间联合自主轨道确定(LAOD)。首先,建立了基于星间测距的地月空间联合自主定轨模型;其次,讨论了利用halo导航星联合自主定轨的可观性;最后,数值分析了不同误差条件下导航星与用户星的联合自主定轨精度,其中用户星轨道涵盖了典型的地月空间任务轨道,包括低地球轨道(LEO)、地月转移飞行轨道(CTT)和环月低轨道(LLO)。针对CTT自主定轨精度问题,特别分析了利用2颗halo导航星的定轨情况。结果表明,单颗halo导航星条件下LEO和LLO的定轨精度最高,导航星次之,CTT最差,增加1颗halo导航星可将CTT的定轨精度提高至少2倍,可为星间联合自主轨道确定技术在后续月球和深空探测任务中的应用提供参考借鉴。 展开更多
关键词 HALO轨道 星间测量 联合自主定轨 地月空间 月球探测
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Continuum Skyrme Hartree-Fock-Bogoliubov theory with Green’s function method for neutron-rich Ca,Ni,Zr,and Sn isotopes 被引量:3
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作者 En-Bo Huo Ke-Ran Li +2 位作者 Xiao-Ying Qu Ying Zhang Ting-Ting Sun 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第7期162-178,共17页
The possible exotic nuclear properties in the neutron-rich Ca,Ni,Zr,and Sn isotopes are examined with the continuum Skyrme Hartree-Fock-Bogoliubov theory in the framework of the Green’s function method.The pairing co... The possible exotic nuclear properties in the neutron-rich Ca,Ni,Zr,and Sn isotopes are examined with the continuum Skyrme Hartree-Fock-Bogoliubov theory in the framework of the Green’s function method.The pairing correlation,the couplings with the continuum,and the blocking effects for the unpaired nucleon in odd-A nuclei are properly treated.The Skyrme interaction SLy4 is adopted for the ph channel and the density-dependentinteraction is adopted for the pp chan-nel,which well reproduce the experimental two-neutron separation energies S_(2n)and one-neutron separation energies Sn.It is found that the criterion S_(n)>0 predicts a neutron drip line with neutron numbers much smaller than those for S_(2n)>0.Owing to the unpaired odd neutron,the neutron pairing energies−E_(pair)in odd-A nuclei are much lower than those in the neighbor-ing even-even nuclei.By investigating the single-particle structures,the possible halo structures in the neutron-rich Ca,Ni,and Sn isotopes are predicted,where sharp increases in the root-mean-square(rms)radii with significant deviations from the traditional rA^(1∕3)rule and diffuse spatial density distributions are observed.Analyzing the contributions of various partial waves to the total neutron densityρlj(r)∕ρ(r)reveals that the orbitals located around the Fermi surface-particularly those with small angular momenta-significantly affect the extended nuclear density and large rms radii.The number of neutrons Nλ(N_(0))occupying above the Fermi surfacen(continuum threshold)is discussed,whose evolution as a function of the mass number A in each isotope is consistent with that of the pairing energy,supporting the key role of the pairing correlation in halo phenomena. 展开更多
关键词 Neutron-rich nuclei Neutron halo Skyrme Hartree-Fock-Bogoliubov theory Green’s function method
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Research on the influence of quadrupole deformation and continuum effects on the exotic properties of 15,17,19B with the complex momentum representation method 被引量:2
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作者 Xue‑Neng Cao Xian‑Xian Zhou +1 位作者 Ming Fu Xin‑Xing Shi 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第2期98-108,共11页
The properties of exotic nuclei are the focus of the present research.Two-neutron halo structures of neutron-rich17,19B were experimentally confirmed.We studied the formation mechanism of halo phenomena in17,19B using... The properties of exotic nuclei are the focus of the present research.Two-neutron halo structures of neutron-rich17,19B were experimentally confirmed.We studied the formation mechanism of halo phenomena in17,19B using the complex momentum representation method applied to deformation and continuum coupling.By examining the evolution of the weakly bound and resonant levels near the Fermi surface,s–d orbital reversals and certain prolate deformations were observed.In addition,by analyzing the evolution of the occupation probabilities and density distributions occupied by valence neutrons,we found that the ground state of15B did not exhibit a halo and the ground states of17B and19B exhibited halos at 0.6≤β2≤0.7 and0.3≤β2≤0.7,respectively.The low-l components in the valence levels that are weakly bound or embedded in the continuous spectrum lead to halo formation. 展开更多
关键词 Quadrupole deformation Resonant states Complex momentum representation HALO
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Detection of the Milky Way Reflex Motion Caused by the Magellanic Clouds in Different Observation Accuracy
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作者 Ya-Nan Cao Hao Tian +4 位作者 Shi Shao Xiang-Xiang Xue Yi-Zhou Liu Zhou Fan Jing Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第8期247-255,共9页
Motivated by recent studies of the perturbation of the Magellanic Clouds(MCs)on the Milky Way(MW)and the planned multi-band wide-field deep survey named Chinese Space Station Telescope(CSST),we explore the detection l... Motivated by recent studies of the perturbation of the Magellanic Clouds(MCs)on the Milky Way(MW)and the planned multi-band wide-field deep survey named Chinese Space Station Telescope(CSST),we explore the detection limit of the MW reflex motion due to the MCs infall in different observation precision using an MW-MCs-mass galaxy from MAGPIE simulation to provide a reference for the CSST survey.By involving different errors of distance,proper motion,and radial velocity,we investigate the reflex motion characterized by the velocity shift in each velocity component.We find the strongest shifts in the tangential velocities,which align with the motion direction of the MCs.In the ideal case that distance errors dominate,we find a relative distance error of 10%can allow the reliable detection of velocity shifts in tangential velocities within 100 kpc,and a relative distance error of 30%is the minimum requirement to detect the reliable tangential velocity shifts of about 40kms^(-1)within 50 kpc.Different errors of proper motions in combination with a relative distance error of 10%or 20%show an error of 0.1 mas yr^(-1)in proper motions can guarantee the reliable detection of velocity shifts in V_(l)and V_(b)up to 80-100 kpc and an error of 0.15 mas yr^(-1)is the minimum requirement.In the other ideal case that radial velocity errors dominate,we find a radial velocity error of 20kms^(-1)can present reliable reflex motion in line-of-sight velocity up to 70 kpc,while the detection volume will be reduced to 50 kpc as the radial velocity error increases to 40kms^(-1).When the radial velocity error is larger than 60kms^(-1),the velocity shifts cannot be detected anymore.In addition,we find that reliable detection of reflex motion requires at least 20%of the whole sample. 展开更多
关键词 GALAXY kinematics and dynamics-(galaxies:)Magellanic Clouds-Galaxy HALO
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Semiconducting SWCNT Photo Detector for High Speed Switching Through Single Halo Doping
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作者 A.Arulmary V.Rajamani T.Kavitha 《Computer Systems Science & Engineering》 SCIE EI 2023年第8期1617-1630,共14页
The method opted for accuracy,and no existing studies are based on this method.A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube(SWCNT)Field Effect Transistor as a ... The method opted for accuracy,and no existing studies are based on this method.A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube(SWCNT)Field Effect Transistor as a photodetector is carried out.In the proposed device,better performance is achieved by increasing the diameter and introducing a new single halo(SH)doping in the channel length of the CNTFET device.This paper is a study and analysis of the performance of a Carbon Nano Tube Field Effect Transistor(CNTFET)as a photodetector using the self-consistent Poisson and Green function method.The 2D self-consistent Poisson and Green’s function method for various optical intensities and wavelength simulate this proposed photodetector.The performance study is based on the simulation of drain current,transconductance,sub-threshold swing,cut-off frequency,gain,directivity,and quantum efficiency under dark and illuminated conditions.These quantum simulation results show that cut-off frequency increases while there is an increase in diameter.The proposed SH-CNTFET provides better performance in terms of higher gain and directivity than conventional CNTFET(C-CNTFET).This device will be helpful in optoelectronic integrated circuits(OEIC)receivers due to its superior performance. 展开更多
关键词 Single halo CNTFET self-consistent poisson equation green’s function photodetector
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Mock X-Ray Observations of Hot Gas with L-Galaxies Semi-analytic Models of Galaxy Formation
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作者 Wenxin Zhong Jian Fu +1 位作者 Shiyin Shen Feng Yuan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第7期37-51,共15页
We create mock X-ray observations of hot gas in galaxy clusters with a new extension of the L-Galaxies semianalytic model of galaxy formation,which includes the radial distribution of hot gas in each halo.Based on the... We create mock X-ray observations of hot gas in galaxy clusters with a new extension of the L-Galaxies semianalytic model of galaxy formation,which includes the radial distribution of hot gas in each halo.Based on the model outputs,we first build some mock light cones,then generate mock spectra with the SOXS package and derive the mock images in the light cones.Using the mock data,we simulate mock X-ray spectra for the ROSAT all-sky survey,and compare the mock spectra with the observational results.Then,we consider the design parameters of the HUBS mission and simulate the observation of the halo hot gas for HUBS as an important application of our mock work.We find:(1)our mock data match the observations by current X-ray telescopes.(2)The survey of hot baryons in resolved clusters by HUBS is effective below redshift 0.5,and the observations of the emission lines in point-like sources at z>0.5 by HUBS help us understand the hot baryons in the early universe.(3)By taking advantage of the large simulation box and flexibility in semi-analytic models,our mock X-ray observations provide the opportunity to select targets and observation strategies for forthcoming X-ray facilities. 展开更多
关键词 X-rays:galaxies:clusters galaxies:clusters:intracluster medium galaxies:groups:general galaxies:halos (galaxies:)intergalactic medium
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Pulmonary reversed halo cycles and consolidations after immunotherapy:A case report
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作者 Hong Suo Yu-Jie Shi +2 位作者 Zhao-Di Huang Kai Xu Hui Huang 《World Journal of Clinical Cases》 SCIE 2023年第28期6938-6942,共5页
BACKGROUND Immune checkpoint inhibitor-associated interstitial lung disease(ICI-ILD)and opportunistic pneumonias are the main pulmonary complications during immunotherapy for malignancies.The organizing pneumonia(OP)p... BACKGROUND Immune checkpoint inhibitor-associated interstitial lung disease(ICI-ILD)and opportunistic pneumonias are the main pulmonary complications during immunotherapy for malignancies.The organizing pneumonia(OP)pattern is one of the common radiological manifestations of ICI-ILD,and OP is the most common cause of reversed halo cycles and consolidations.However,opportunistic pneumonias should be excluded.CASE SUMMARY In this report,we described a case of a 44-year-old man with esophageal cancer who showed multiple reversed-halo cycles and consolidations on chest computed tomography(CT)after he had a cold during immunotherapy.He was diagnosed with esophageal squamous-cell cancer(T2NIM0)after surgery.Then,he was successfully treated with 6 cycles of chemotherapy plus tislelizumab,one cycle of radiotherapy and 9 cycles of tislelizumab.Two months later,he complained of low-grade fever and cough with nonpurulent sputum after he had a cold.Community-acquired pneumonia was considered,but moxifloxacin was ineffective.Chest CT showed multiple reversed-halo cycles and consolidations.Mycobacterium tuberculosis was identified with next-generation sequence analysis of bronchoalveolar lavage fluid(BALF).Two months later,he improved with standard anti-tuberculosis medications.Both the cycles and consolidations disappeared in the repeat CT after 6 mo of medications.CONCLUSION When chest CT shows reversed-halo cycles and consolidations in patients during anticancer immunotherapy,both ICI-ILD and infectious pneumonia should be considered.BALF microbiological analysis was helpful to differentiate them. 展开更多
关键词 Reversed halo cycles Consolidations IMMUNOTHERAPY TUBERCULOSIS Checkpoint inhibitor associated interstitial lung disease Case report
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刚落月又探日印度首个太阳探测器升空
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作者 张晨 《太空探索》 2023年第10期48-53,共6页
2023年9月2日14时20分,印度的PSLVXL运载火箭将印度首个太阳探测器“太阳神-L1”(Aditya-L1,Aditya是梵语中太阳的名字)从萨迪什·达万航天中心送入预定轨道。虽然火箭飞行出现一些问题,但还是将探测器准确送入预定轨道。该探测器... 2023年9月2日14时20分,印度的PSLVXL运载火箭将印度首个太阳探测器“太阳神-L1”(Aditya-L1,Aditya是梵语中太阳的名字)从萨迪什·达万航天中心送入预定轨道。虽然火箭飞行出现一些问题,但还是将探测器准确送入预定轨道。该探测器将经过127天的飞行后抵达环绕日地L1点的Halo轨道。这是印度首个太阳探测器,如果不出意外的话,也是印度首个抵达日地L1点的航天器。 展开更多
关键词 预定轨道 航天中心 HALO轨道 运载火箭 探测器 太阳神 航天器 印度
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