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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 194-203页

作者： WANG zhen LI Huajian HUANG Fali YANG Zhiqiang WEN Jiaxin SHI Henan Railway Engineering Research Institute China Academy of Railway Science Corporation LimitedBeijing 100081China State Key Laboratory for Track Technology of High-Speed Railway Beijing 100081China

In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMc)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(c60,c80,c100)as *** evolution of mechanical properties of HMc and the correlation between cubic compressive strength and other mechanical properties are *** to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of *** powder content displays both positive and negative effects on mechanical properties of HMc,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.

关键词： manufactured sand concrete railway mechanical property lithology stone powder content

chandra Studies of the X-ray gas properties of fossil systems

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Research in Astronomy and Astrophysics 2016年第3期16卷 129-138页

作者： zhen-zhen Qin School of Science Southwest University of Science and Technology

We study ten galaxy groups and clusters suggested in the literature to be ＂fossil systems（FSs）＂based on chandra observations. According to the M（500）- T and LX- T relations, the gas properties of FSs are not physically distinct from ordinary galaxy groups or clusters. We also first study the f（gas, 2500）- T relation and find that the FSs exhibit the same trend as ordinary systems. The gas densities of FSs within 0.1r200 are - 10^-3cm^-3, which is the same order of magnitude as galaxy clusters. The entropies within 0.1r200（S（0.1r200）） of FSs are systematically lower than those in ordinary galaxy groups, which is consistent with previous reports, but we find their S（0.1r200）- T relation is more similar to galaxy clusters. The derived mass profiles of FSs are consistent with the Navarro, Frenk and White model in（0.1- 1）（r200）, and the relation between scale radius rs and characteristic mass density δc indicates self-similarity of dark matter halos of FSs. The ranges of rs and δc for FSs are also close to those of galaxy clusters. Therefore, FSs share more common characteristics with galaxy clusters. The special birth place of the FS makes it a distinct type of galaxy system.

关键词： galaxies: cluster: general -- galaxies: evolution -- galaxies: halos -- intergalactic medium --X-ray: galaxies: clusters

Emergent Z2 topological invariant and robust helical edge states in two-dimensional topological metals

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Science china(Physics,Mechanics & Astronomy) 2020年第10期63卷 105-110页

作者： chui-zhen chen Hua Jiang Dong-Hui Xu X.c.Xie Institute for Advanced Study and School of Physical Science and Technology Soochow UniversitySuzhou 215006China Department of Physics Hubei UniversityWuhan 430062China International center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China cAS center for Excellence in Topological Quantum computation University of Chinese Academy of SciencesBeijing 100190China Beijing Academy of Quantum Information Sciences Beijing 100193China

In this work,we study the effects of disorder on topological metals that support a pair of helical edge modes deeply embedded inside the gapless bulk ***,we predict that a quantum spin Hall(QSH)phase can be obtained from such topological metals without opening a global band *** be specific,disorder can lead to a pair of robust helical edge states which is protected by an emergent Z2 topological invariant,giving rise to a quantized conductance plateau in transport *** results are instructive for solving puzzles in various transport experiments on QSH materials that are intrinsically *** work also will inspire experimental realization of the QSH effect in disordered topological metals.

关键词： topological metal disorder Z2 topological invariant

An improved pulse coupled neural networks model for semantic IoT

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Digital communications and Networks 2024年第3期10卷 557-567页

作者： Rong Ma zhen Zhang Yide Ma Xiping Hu Edith c.H.Ngai Victor c.M.Leung School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China School of Medical Technology Beijing Institute of TechnologyBeijing100081China Department of Electrical and Electronic Engineer The University of Hong KongHong Kong 999077China college of computer Science and Software Engineering Shenzhen UniversityShenzhen 518060China Department of Electrical and computer Engineering the University of British ColumbiaVancouverBC V6T 1Z4Canada

In recent years,the Internet of Things(IoT)has gradually developed applications such as collecting sensory data and building intelligent services,which has led to an explosion in mobile data ***,with the rapid development of artificial intelligence,semantic communication has attracted great attention as a new communication ***,for IoT devices,however,processing image information efficiently in real time is an essential task for the rapid transmission of semantic *** the increase of model parameters in deep learning methods,the model inference time in sensor devices continues to *** contrast,the Pulse coupled Neural Network(PcNN)has fewer parameters,making it more suitable for processing real-time scene tasks such as image segmentation,which lays the foundation for real-time,effective,and accurate image ***,the parameters of PcNN are determined by trial and error,which limits its *** overcome this limitation,an Improved Pulse coupled Neural Networks(IPcNN)model is proposed in this *** IPcNN constructs the connection between the static properties of the input image and the dynamic properties of the neurons,and all its parameters are set adaptively,which avoids the inconvenience of manual setting in traditional methods and improves the adaptability of parameters to different types of *** segmentation results demonstrate the validity and efficiency of the proposed self-adaptive parameter setting method of IPcNN on the gray images and natural images from the Matlab and Berkeley Segmentation *** IPcNN method achieves a better segmentation result without training,providing a new solution for the real-time transmission of image semantic information.

关键词： Internet of things(IoT) Semantic information Real-time application Improved pulse coupled neural network Image segmentation

Half-quantized helical hinge currents in axion insulators

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National Science Review 2023年第9期10卷 154-162页

作者： Ming Gong Haiwen Liu Hua Jiang chui-zhen chen X.-c.Xie International center for Quantum Materials School of Physics Peking University center for Advanced Quantum Studies Department of Physics Beijing Normal University 3. School of Physical Science and Technology Soochow University 4. Institute for Advanced StudySoochow University 5. CAS Center for Excellence in Topological Quantum ComputationUniversity of Chinese Academy of Sciences

Fractional quantization can emerge in noncorrelated systems due to the parity anomaly,while its condensed matter realization is a challenging *** propose that in axion insulators(AIs),parity anomaly manifests a unique fractional boundary excitation:the half-quantized helical hinge *** helical hinge currents microscopically originate from the lateral Goos-H?nchen(GH) shift of massless side-surface Dirac electrons that are totally reflected from the ***,due to the presence of the massive top and bottom surfaces of the AI,the helical current induced by the GH shift is *** semiclassical wave packet analysis uncovers that the hinge current has a topological origin and its half quantization is robust to parameter ***,we propose an experimentally feasible six-terminal device to identify the half-quantized hinge channels by measuring the nonreciprocal *** results advance the realization of the half-quantization and topological magneto electric responses in AIs.

关键词： axion insulator parity anomaly half-quantization Goos-Hänchen effect topological magnetoelectric effect

Quantum to classical crossover under dephasing effects in a two-dimensional percolation model

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Science china(Physics,Mechanics & Astronomy) 2020年第2期63卷 130-134页

作者： Junjie Qi Haiwen Liu chui-zhen chen Hua Jiang X.c.Xie International center for Quantum Materials and School of Physics Peking UniversityBeijing 100871China collaborative Innovation center of Quantum Matter Beijing 100871China center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China Institute for Advanced Study and School of Physical Science and Technology Soochow UniversitySuzhou 215006China

Scaling theory predicts complete localization in d = 2 in quantum systems belonging to the orthogonal class(i.e., with timereversal symmetry and spin-rotation symmetry). The conductance g behaves as g^exp(-L/l) with system size L and localization length l in the strong disorder limit. However, classical systems can always have metallic states in which Ohm’s law shows a constant g in d=2. We study a two-dimensional quantum percolation model by controlling dephasing effects. The numerical investigation of g aims at simulating a quantum-to-classical percolation evolution. An unexpected metallic phase, where g increases with L, generates immense interest before the system becomes completely classical. Furthermore, the analysis of the scaling plot of g indicates a metal-insulator crossover.

关键词： quantum percolation model dephasing effects metal-insulator crossover

Doped low-density parity-check codes

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Digital communications and Networks 2024年第1期10卷 217-226页

作者： Yong Li Rui Liu Xianlong Jiao Youqiang Hu zhen Luo Francis c.M.Lau college of computer Science Chongqing UniversityChongqing400044China School of Automation Chongqing UniversityChongqing400044China college of Electronic and Information Engineering Southwest UniversityChongqing400715China Future Wireless Networks and IoT Focusing Area Department of Electronic and Information EngineeringHong Kong Polytechnic UniversityHong KongChina

In this paper,we propose a doping approach to lower the error floor of Low-Density Parity-check(LDPc)*** doping component is a short block code in which the information bits are selected from the coded bits of the dominant trapping sets of the LDPc ***,an algorithm for selecting the information bits of the short code is proposed,and a specific two-stage decoding algorithm is *** results demonstrate that the proposed doped LDPc code achieves up to 2.0 dB gain compared with the original LDPc code at a frame error rate of 10^(-6)Furthermore,the proposed design can lower the error floor of original LDPc codes.

关键词： LDPc codes Doped LDPc codes Tanner graph Quadratic residue codes Trapping sets

Geochemistry, Geochronology and Lu-Hf Isotopes of Peraluminous Granitic Porphyry from the Walegen Au Deposit, West Qinling Terrane

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Acta Geologica Sinica(English Edition) 2017年第6期91卷 2024-2040页

作者： GUO Xianqing YAN zhen Jonathan c.AITcHISON FU changlei WANG Zongqi MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences Institute of Geology Chinese Academy of Geological Sciences School of Earth and Environmental Sciences (SEES) Faculty of ScienceThe University of Queensland

Walegen Au deposit is closely correlated with granitic intrusions of Triassic age, which are composed of granite and quartz porphyries. Both granite porphyry and quartz porphyry consist of quartz, feldspar and muscovite as primary minerals. WeaMy peraluminous granite porphyry （A/ cNK=1.10-1.15） is enriched in LREE, depleted in HREE with Nb-Ta-Ti anomalies, and displays subduction-related geochemistry. Quartz porphyry is strongly peraluminous （A/cNK=1.64-2.81） with highly evolved components, characterized by lower TiO2, REE contents, Mg#, K/Rb, Nb/Ta, Zr/Hf ratios and higher Rb/Sr ratios than the granite porphyry. REE patterns of quartz porphyry exhibit lanthanide tetrad effect, resulting from mineral fractionation or participation of fluids with enriched F and cI. LA- IcP-MS zircon U-Pb dating indicates quartz porphyry formed at 233±3 Ma. The ages of relict zircons from Triassic magmatic rocks match well with the detrital zircons from regional area. In addition, εHf（t） values of Triassic magmatic zircons from the granite and quartz porphyries are -14.2 to -9.1 （with an exception of ＋4.1） and -10.8 to -8.6 respectively, indicating a crustal-dominant source. Regionally, numerous Middle Triassic granitoids were previously reported to be formed under the consumption of Paleotethyan Ocean. These facts indicate that the granitic porphyries from Walegen Au deposit may have been formed in the processes of the closing of Paleotethyan Ocean, which could correlate with the arc-related magmatism in the Kunlun orogen to the west and the Qinling orogen to the east.

关键词： Triassic granites lanthanide tetrad effect subduction-related magmatism Walegen Au deposit West Qinling terrane

In Vitro Study on Mg-Sn-Mn Alloy as Biodegradable Metals

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Journal of Materials Science & Technology 2014年第7期30卷 675-685页

作者： zhen zhen Tingfei Xi Yufeng zheng Li Li Lugee Li center for Biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary StudiesPeking University Biomedical Engineering Research center Shenzhen InstitutePeking University Department of Materials Science and Engineering College of EngineeringPeking University center for Biomedical Materials and Engineering Harbin Engineering University Dongguan EONTEc company Ltd

The mechanical properties, chemical properties and biocompatibility of Mg-3Sn-0.5Mn alloy were tested. A series of in vitro evaluations such as tensile test, static and dynamic immersion test, hemocompatibility test as well as cytotoxicity test were presented, with commercial magnesium alloy WE43 as the control. Mg-3Sn-0.5Mn alloy possesses suitable strength and superior duc.ility compared with WE43 and AZ31. Static immersion and dynamic degradation tests showed more uniform degradation with a more moderate rate for Mg-3Sn-0.5Mn alloy （0.34 mm/y in static condition and 0.25 mm/y in dynamic condition） compared with WE43 alloy （0.42 mm/y in static condition and 0.33 mm/y in dynamic condition） in Hank＇s solution. Blood compatibility evaluation suggested that Mg-3Sn-0.5Mn alloy had no destructive effect on erythrocyte and showed excellent anti-thrombogenicity to blood system. Besides, Mg-3Sn-0.5Mn alloy showed no inhibition effect to L929 metabolic activity and mild toxicity to vascular smooth muscle cell （VSMc） in preliminary cell viability assessment. By considering its excellent mechanical strength, corrosion resistance, low ion release rate and good biocompatibility, Mg-3Sn-0.5Mn alloy may be a promising economical candidate as biomedical implant material for load-bearing clinical applications in the future.

关键词： Mg-3Sn-0.5Mn alloy corrosion Dynamic immersion Static immersion Biodegradable material

Dislocation self-interaction in TiAl:Evolution of super-dislocation dipoles revealed by atomistic simulations

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Journal of Materials Science & Technology 2021年第10期69卷 138-147页

作者： Z.zhen H.Wang c.Y.Teng c.G.Bai D.S.Xu R.Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of China.Shenyang 110016China School of Materials Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China Laboratory of Fundamental Research AVIC China Aero-Polytechnology EstablishmentBeijing 100028.China

As one of the fundamental outcomes of dislocation self-interaction,dislocation dipoles have an important influence on the plastic deformation of materials,especially on fatigue and *** this work,superdislocation dipoles inγ-TiAl andα_(2)-Ti_(3)Al were systematically investigated by atomistic simulations,with a variety of dipole heights,orientations and annealing tempe *** results indicate that non-screw super-dipoles transform into locally stable dipolar or reconstructed cores at low temperature,while into isolated or interconnected point defect clusters and stacking fault tetrahedra at high temperature via short-range diffu ***-screw super-dipoles inγ-TiAl andα_(2)-Ti_(3)Al exhibit similar features as fcc and hcp metals,***,over long-term annealing where diffusion is significant,60°superdipoles inγ-TiAl are stable,whereas the stability of super-dipoles inα2-Ti3 Al increases with dipole height and orientation *** influence on mechanical properties can be well evaluated by integrating these results into mesoscale or constitutive models.

关键词： TiAl Dislocation Dipole Mechanical property Atomistic simulation