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Bone three-dimensional microstructural features of the common osteoporotic fracture sites

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World Journal of Orthopedics 2014年第4期5卷 486-495页

作者： huayue chen Kin-ya Kubo Department of Anatomy Gifu University Graduate School of Medicine Seijoh University Graduate School of Health Care Studies

Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fractures are of global health and socioeconomic importance. The three-dimensional microstructural information of the common osteoporosis-related fracture sites, including vertebra, femoral neck and distal radius, is a key for fully understanding osteoporosis pathogenesis and predicting the fracture risk. Low vertebral bone mineral density(BMD) is correlated with increased fracture of the spine. Vertebral BMD decreases from cervical to lumbar spine, with the lowest BMD at the third lumbar vertebra. Trabecular bone mass of the vertebrae is much lower than that of the peripheral bone. Cancellous bone of the vertebral body has a complex heterogeneous three-dimensional microstructure, with lower bone volume in the central and anterior superior regions. Trabecular bone quality is a key element to maintain the vertebral strength. The increased fragility of osteoporotic femoral neck is attributed to low cancellous bone volume and high compact porosity. Compared with age-matched controls, increased cortical porosity is observed at the femoral neck in osteoporoticfracture patients. Distal radius demonstrates spatial inhomogeneous characteristic in cortical microstructure. The medial region of the distal radius displays the highest cortical porosity compared with the lateral, anterior and posterior regions. Bone strength of the distal radius is mainly determined by cortical porosity, which deteriorates with advancing age.

关键词： Osteoporosis Fracture Microstructure Trabecular bone Cortical bone Vertebra Femoral neck Distal radius

Effects of electron trapping on nonlinear electron-acoustic waves excited by an electron beam via particle-in-cell simulations

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Plasma Science and Technology 2019年第5期21卷 93-101页

作者： Quanming LU huayue chen Yangguang KE Shui WANG CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of ChinaHefei 230026People's Republic of China National Centre for Physics(NCP)at Quaid-e-Azam University Campus Shahdra Valley Road.Islamabad 44000Pakistan Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics University of Science and Technology of ChinaHefei 230026People's Republic of China

By performing one-dimensional particle-in-cell simulations, the nonlinear effects of electronacoustic(EA) waves are investigated in a multispecies plasma, whose constituents are hot electrons, cold electrons, and beam electrons with immobile neutralized positive ions. Numerical analyses have identified that EA waves with a sufficiently large amplitude tend to trap cold electrons. Because EA waves are dispersive, where the wave modes with different wavenumbers have different phase velocities, the trapping may lead to the mixing of cold electrons. The cold electrons finally get thermalized or heated. The investigation also shows that the excited EA waves give rise to a broad range of wave frequencies, which may be helpful for understanding the broadband-electrostatic-noise spectrum in the Earth’s auroral region.

关键词： electron acoustic waves cold electrons trapping particle-in-cell(PIC)simulation

In situ evidence of resonant interactions between energetic electrons and whistler waves in magnetopause reconnection

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Earth and Planetary Physics 2019年第6期3卷 467-473页

作者： Zhi Li QuanMing Lu RongSheng Wang XinLiang Gao huayue chen Chinese Academy Sciences Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of ChinaHefei 230026China Chinese Academy Sciences Center for Excellence in Comparative Planetology Hefei 230026China

In this paper,we analyze one reconnection event observed by the Magnetospheric Multiscale(MMS)mission at the earth’s *** this event,the spacecraft crossed the reconnection current sheet from the magnetospheric side to the magnetosheath side,and whistler waves were observed on both the magnetospheric and magnetosheath *** the magnetospheric side,the whistler waves propagated quasi-parallel to the magnetic field and toward the X-line,while on the magnetosheath side they propagated almost anti-parallel to the magnetic field and away from the *** with the enhancement of the whistler waves,we find that the fluxes of energetic electrons are concentrated around the pitch angle 90°when their energies are higher than the minimum energy that is necessary for the resonant interactions between the energetic electrons and whistler *** observation provides in situ observational evidence of resonant interactions between energetic electrons and whistler waves in the magnetic reconnection.

关键词： magnetic reconnection whistler waves magnetosphere energetic electrons

Frequency Bands and Gaps of Magnetospheric Chorus Waves Generated by Resonant Beam/Plateau Electrons

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Journal of Modern Physics 2022年第6期13卷 864-891页

作者： Konrad Sauer huayue chen Eduard Dubinin Quanming Lu CAS Key Laboratory of Geoscience Environment School of Earth and Space Sciences University of Science and Technology of China Hefei China CAS Center of Excellence in Comparative Planetology Hefei China Max-Plnack Institute for Solar System Research G&ouml ttingen Germany

In this paper, the modifications of the whistler dispersion characteristics are investigated which arise if resonant electrons are taken into account. The following chain of processes is emphasized: Generation of whistler waves propagating at different angles to the magnetic field and their nonlinear interaction with resonant electrons result in the appearance of modulated electron beams in the background plasma. As a result, the dispersion characteristics of waves in this new plasma might be significantly changed. By analysing the modified dispersion characteristics these changes are discussed. Supported by particle simulations and space observations, it is assumed that in the electron distribution function at the resonance velocity a plateau-like beam is formed. Because of the weakness of the beam, the term “beam/plateau population (b/p)” is used. By solving the kinetic dispersion relation of whistler waves in electron plasmas with b/p populations, the associated modifications of the whistler dispersion characteristics are presented in diagrams showing, in particular, the frequency versus propagation angle dependence of the excited waves. It is important to point out the two functions of the b/p populations. Because of the bi-directional excitation of whistler waves by temperature anisotropy, one has to distinguish between up- and downstream populations and accordingly between two b/p modes. The interaction of the beam-shifted cyclotron mode ω= Ωe + k⋅Vb (V bVb is the b/p velocity, Ωe: electron cyclotron frequency) with the whistler mode leads to enhanced damping at the ω-k point where they intersect. This is the origin of the frequency gap at half the electron cyclotron frequency (ω~Ωe/2) for quasi-parallel waves which are driven by temperature anisotropy. Furthermore, it is shown that the upstream b/p electrons alone (in the absence of temperature anisotropy) can

关键词： Radiation Belts Waves Whistlers Chorus

Study on the RSSI-based Location Algorithm for Wireless Sensor Networks

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Study on the RSSI-based Location Algorithm for Wireless Sens...

2011 International Conference on Economic, Education and Management(ICEEM2011)

作者： huayue chen Jing Pu Miao Yue Computer College China West Normal University

The location of wireless sensor nodes is the fundamental problem in wireless networks,and the merits of its location directly impact the quality of service and the life cycle of wireless sensor *** this paper,it proposes a node location algorithm applied to wireless sensor *** algorithm improves the computational methods of the average distance per hop and the distance from the anchor node by using anchor nodes to clone new and unknown nodes and calculating the corrected value to correct the coordinates of the unknown ***,the RSSI distance measuring technique is used in the ***,it analyzes and verifies its effectiveness on the location error,which shows that the algorithm is an efficient and accurate location algorithm.

关键词： Wireless Sensor Network RSSI Location Node

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基于加权关联规则的用户关注项目推荐算法

计算机工程 2006年第6期32卷 86-88页

作者：陈华月余刚朱征宇重庆大学计算机学院

根据每个项受关注的程度对其赋予权值,体现每个项在项集中的重要性,引入选择关注度,体现用户选择项时的倾向,推荐时将其与关联规则的置信度相结合,从而为用户更准确的提供关注项目推荐。在实验中比较了文中的算法和一种基于最近邻用户... 详细信息

根据每个项受关注的程度对其赋予权值,体现每个项在项集中的重要性,引入选择关注度,体现用户选择项时的倾向,推荐时将其与关联规则的置信度相结合,从而为用户更准确的提供关注项目推荐。在实验中比较了文中的算法和一种基于最近邻用户协作过滤算法,实验验证了文中的算法在为用户进行推荐项目时用户的点击率和算法的性能都有所提高。

关键词：加权关联规则选择关注度项目推荐

Statistical analysis of relativistic electron precipitation in the magnetosphere from POES observations

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Statistical analysis of relativistic electron precipitation ...

2019年中国地球科学联合学术年会

作者： huayue chen Xinliang Gao Quanming Lu N.A.Tsyganenko Yongcun Zhang University of Science and Technology of China Saint Petersburg State University Department of Earth's Physics Saint Petersburg State University State Key Laboratory of Space Weather National Space Science Center

In this letter, we investigate the characters of relativistic electron precipitation(REP), which is derived from seven NOAA Polar-orbiting Operational Environmental Satellites(POES) in the time period from Jan 2012 to... 详细信息

关键词： Statistical analysis of relativistic electron precipitation in the magnetosphere from POES observations REP

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地球磁层中三波段合声波的激发机制

中国科学技术大学学报 2020年第9期50卷 1249-1257页

作者：陈瑞高新亮陈华岳王水中国科学技术大学地球和空间科学学院中国科学院近地空间环境重点实验室安徽合肥230026 中国科学院比较行星学卓越创新中心安徽合肥230026

地球磁层中存在着三波段合声波,它的频谱中有两个明显的能量间断.利用范艾伦探针的观测数据,提出了一种新的激发机制来解释三波段合声波的产生.在观测到三波段合声波时,通常伴随着两束与合声波传播方向相反的电子束流.根据线性理论计算... 详细信息

地球磁层中存在着三波段合声波,它的频谱中有两个明显的能量间断.利用范艾伦探针的观测数据,提出了一种新的激发机制来解释三波段合声波的产生.在观测到三波段合声波时,通常伴随着两束与合声波传播方向相反的电子束流.根据线性理论计算出的合声波的增长率,发现两束电子束流的存在确实能使反方向传播的波动的增长率出现两个极小值.因此,两个特定频率处的合声波被阻尼,从而形成两个能量间断,并导致合声波呈现三个波段的特征.这一工作不仅提出了一种新的机制来解释三波段合声波的产生,还为磁层中经常观测到的合声波在0.5个电子回旋频率处的能量间断提供了新的见解.

关键词：地球磁层三波段合声波能量间断电子束流波粒相互作用

地塞米松对金黄地鼠甲状旁腺超微结构的影响──器官培养的研究

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解剖学报 1995年第2期26卷 206-209页

作者：陈华岳韩永坚浙江医科大学解剖学教研室

应用形态计量学方法，在器官培养条件下，观察了地塞米松对金黄地鼠甲状旁腺超微结构的影响。器官培养２ｈ后，与对照组相比。实验组甲状旁腺主细胞内高尔基复合体发育较差，分泌前颗粒和分泌颗粒数量减少，溶酶体和囊泡样小体增加。器... 详细信息

应用形态计量学方法，在器官培养条件下，观察了地塞米松对金黄地鼠甲状旁腺超微结构的影响。器官培养２ｈ后，与对照组相比。实验组甲状旁腺主细胞内高尔基复合体发育较差，分泌前颗粒和分泌颗粒数量减少，溶酶体和囊泡样小体增加。器官培养２４ｈ后，与对照组相比，实验组甲状旁腺主细胞内高尔基复合体发育较差，分泌前颗粒数量减少，溶酶体和脂滴增加，并可见髓样结构的存在。这些结果提示：在器官培养条件下地塞米松可能对金黄地鼠甲状旁腺的分泌活动有抑制作用。

关键词：主细胞甲状旁腺地塞米松超微结构