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| 1 | ASAF: altered spontaneous activity fingerprinting in Alzheimer’s disease based on multisite fMRI显示文摘Several monocentric studies have noted alterations in spontaneous brain activity in Alzheimer's disease (AD), although there is no consensus on the altered amplitude of low-frequency fluctuations in AD patients. The main aim of the present study was to identify a reliable and reproducible abnormal brain activity pattern in AD. The amplitude of local brain activity (AM), which can provide fast mapping of spontaneous brain activity across the whole brain, was evaluated based on multisite rs-fMRI data for 688 subjects (215 normal controls (NCs), 221 amnestic mild cognitive impairment (aMCI) 252 AD). Two-sample t-tests were used to detect group differences between AD patients and NCs from the same site. Differences in the AM maps were statistically analyzed via the Stouffer's meta-analysis. Consistent regions of lower spontaneous brain activity in the default mode network and increased activity in the bilateral hippocampus/parahippocampus, thalamus, caudate nucleus, orbital part of the middle frontal gyrus and left fusiform were observed in the AD patients compared with those in NCs. Significant correlations (P? | Jiachen Li Dan Jin Ang Li Bing Liu Chengyuan Song Pan Wang Dawei Wang Kaibin Xu Hongwei Yang Hongxiang Yao Bo Zhou Alexandre Bejanin Gael Chetelat Tong Han Jie Lu Qing Wang Chunshui Yu Xinqing Zhang Yuying Zhou Xi Zhang Tianzi Jiang Yong Liu Ying Han | 2019 | Science Bulletin2019，64，14： | 3 |
| 2 | Strain glass transition in high damping Mn-22Cu-5Ni-2Fe alloy显示文摘It has been recognized that the high damping capacity of MnCu based alloys is closely related to the formation of elastic twins as a result of antiferromagnetic transition and martensitic transformation. However, the mechanism for these transitions in this kind of alloy has not been fully understood. For example, previous investigations ascribed the elastic modulus softening prior to martensitic transformation to antiferromagnetic or pre-martensitic transitions, although no convincing evidence was reported. In this paper, an intensive experimental study was made of the modulus softening and microstructural evolution in a typical high damping Mn-22Cu-5Ni-2 Fe alloy, and the evidence of strain glass transition was reported. Such a transition, characterized by a continuous formation of nano-martensite domains, is accompanied by a gradual frequency-dependent modulus softening over a broad temperature range prior to martensitic transformation. | Shiwen Hou Fangyu Qin Jingyun Han Wenlong Xiao Fengshuang Lu Xinqing Zhao | 2018 | Progress in Natural Science:Materials International2018，28，5： | 3 |
| 3 | Impact of EBG Structures' Positions on the Performance of an EBG Antenna显示文摘Six circularly polarized patch antennas with electromagnetic band gap(EBG)arranged at different locations were studied.These EBG antennas were compared in terms of impedance bandwidth,axial ratio(AR)bandwidth and radiation patterns.When the EBG cells were placed closer to the edge of the substrate,the EBG antenna had a larger front radiation and a narrower bandwidth.Integrating the EBG cells closer to the center of the patch resulted in a wider impedance bandwidth,a wider axial ratio bandwidth and a decreased front gain. | Zijian Han Wei Song Xinqing Sheng | 2017 | Journal of Beijing Institute of Technology2017，26，1： | 3 |
| 4 | Microstructure of ultrahigh carbon martensite显示文摘Recent experimental investigations suggest that the martensite formed by quenching carbon steels(0.2–1.26 mass %C) are composed of twins and nanoscale ω particles in twin boundaries, rather than carbon supersaturated uniform solutions. In order to probe the microstructure of the martensite with ultrahigh carbon content, a novel strategy is employed in the present study to obtain ultrahigh carbon martensite(approximate2.1 mass %C) by quenching ductile cast iron. The microstructure of the martensite was intensively characterized by high resolution transmitting electron microscopy. It is indicated that the microstructure of the ultrahigh carbon martensites is composed of ultrafine {112} < 111 >-type twins and high-density nano-scaled ω particles embedded in twin boundaries. These ω nanoparticles in twin boundaries could remarkably impede the deformation of the movement of the nanotwins in martensites, leading to poor ductility and strength of the quenched ductile cast iron. These findings not only reveal the substructures of ultrahigh carbon martensite, but also enhance the understanding of the mechanical behavior of high carbon steels and ductile cast irons. | Chao Wang Yulin Chen Jingyun Han Dehai Ping Xinqing Zhao | 2018 | Progress in Natural Science:Materials International2018，28，6： | 0 |
| 5 | Electronic energy loss and ion velocity correlation effects in track production in swift-ion-irradiated LiNbO_(3):A quantitative assessment between structural damage morphology and energy deposition显示文摘The primary motivation for studying how irradiation modifies the structures and properties of solid materials involves the understanding of undesirable phenomena,including irradiation-induced degradation of components in nuclear reactors and space exploration,and beneficial applications,including material performance tailoring through ion beam modification and defect engineering.In this work,the formation mechanism of latent tracks with different damage morphologies in LiNbO_(3)crystals under 0.09-6.17 Me V/u ion irradiation with an electronic energy loss from 2.6-13.2 ke V/nm is analyzed by experimental characterizations and numerical calculations.Irradiation-induced damage is preliminarily evaluated via the prism coupling technique to analyze the correlation between the dark-mode spectra and energy loss profiles of irradiated regions.Under the irradiation conditions of different ion velocities and electronic energy losses,different damage morphologies,from individual spherical defects to discontinuous and continuous tracks,are experimentally characterized.During ion penetration process,the ion velocity determines the spatiotemporal distribution of deposited irradiation energy induced by electronic energy loss,meaning that the two essential factors including electronic energy loss and ion velocity coaffect the track damage.The inelastic thermal spike model is used to numerically calculate the spatiotemporal evolutions of energy deposition and the corresponding atomic temperature under different irradiation conditions,and a quantitative relationship is proposed by comparison with corresponding experimentally observed track damage morphologies.The obtained quantitative relationship between irradiation conditions and track damage provides deep insight and guidance for understanding the damage behavior of crystal materials in extreme radiation environments and selecting irradiation parameters,including ion species and energies,for ion beam technique application in atomic-level defect manipulation,material modification,and micro/nanofabrication. | Xinqing Han Qing Huang Miguel L.Crespillo Eva Zarkadoula Yong Liu Xuelin Wang Peng Liu | 2022 | Journal of Materials Science & Technology2022，，21： | 0 |
| 6 | Structural damage response of lanthanum and yttrium aluminate crystals to nuclear collisions and electronic excitation:Threshold assessment of irradiation damage显示文摘A comparative analysis is performed on the structural damage response and associated mechanisms in lanthanum aluminate and yttrium aluminate crystals under various irradiation conditions by a combination of experimental and theoretical approaches.Under low-energy Au~+irradiation,the damage accumulation curve shows a higher damage rate for LaAlO_(3)crystals than YAlO_(3)crystals.The relatively low irradiation tolerance of LaAlO_(3)to the action of nuclear collisions is ascribed to the large amorphization cross-section and effective cross-section for defect-stimulated amorphization.Under swift Ar^(12+),Ni^(19+)and Kr^(17+)irradiation with different ion energies and velocities,the formed highly-disordered/amorphous latent tracks with different morphologies in pristine and predamaged crystals are discussed,and the corresponding electronic energy loss and lattice temperature thresholds are quantitatively determined.Compared to YAlO_(3),LaAlO_(3)exhibits lower sensitivity and higher damage tolerance to the electronic energy loss process,attributing to its relatively high recrystallization efficiency during the rapid quenching process.Furthermore,the introduction of lattice defects into LaAlO_(3)and YAlO_(3)crystals considerably enhances the sensitivity and intensity of thermal spike response to the electronic energy loss,and the induced effective modification of track morphologies demonstrates the synergistic effect between the electronic energy loss and pre-existing defects created by nuclear collisions.In this case,even under the action of electronic energy loss below the threshold,the lattice temperature in the nuclear-collision damaged crystalline system could still meet the criterion for track production.The irradiation energy deposited to atoms and induced lattice temperature evolution discussed in this work provide a deeper insight into the complex processes involved in irradiation-induced latent track behaviors. | Yong Liu Xinqing Han Qing Huang Miguel L.Crespillo Peng Liu Eva Zarkadoula Xuelin Wang | 2021 | Journal of Materials Science & Technology2021，，31： | 0 |
| 7 | High-Gain and Low-RCS Patch Antenna Array Based on Slot-EBG Structure显示文摘A novel low radar cross-section(RCS)and high gain patch antenna array is proposed.A pair of slots introduced on the mushroom electromagnetic bandgap(EBG)patch realize polarization-dependency and act as parasitic radiation to enhance the antenna gain.A chessboard-like configuration composed of slot-EBG blocks is further equipped on the antenna array for scattering cancellation.Optimizing the layout pattern enables the designing of a high-gain and low-RCS antenna array using the slot-EBGs.Full-wave simulations validate that a front gain enhancement of more than 2.5.dB in the operating frequency band and low-RCS in a broad frequency band for normal incidence are obtained by the proposed antenna array. | Zijian Han Wei Song Xinqing Sheng Wenbo Zheng | 2019 | Journal of Beijing Institute of Technology2019，28，4： | 0 |
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