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Gradient C f /ZrB 2 -SiC composites integrating low-density, good mechanical properties and heat-resistant

Journal of Materials science & technology 2026年 242卷 156-165页

作者： Qiang Gao Ping Hu Yuxuan Xia Yuan Cheng Guangdong Zhao Jiaxin Feng Zibin Chen Xinghong Zhang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Center for Composite Materials and Structures Harbin Institute of Technology Harbin 150080 China Beijing Power Machinery Institute The Third Academy of State-owned Aerospace Giant China Aerospace Science & Industry Corporation (CASIC) Beijing 100074 China School of Chemistry and Materials Science Heilongjiang University Harbin 150080 China

Ultra-high temperature ceramic composites (UHTCCs) with low density and exceptional heat resistance are essential for hypersonic vehicle applications, enabling increased payload capacity and higher Mach numbers. However, developing a fabrication process that enables UHTCCs with both lightweight and superior thermal protection performance is still a challenge. To tackle this problem, in this study, a combinatorial process of vibration-assisted slurry impregnation and polymer infiltration pyrolysis was developed to fabricate gradient lightweight C f /ZrB 2 -SiC composites, consisting of continuous carbon fiber fabric, ZrB 2 -SiC and a carbon aerogels (CAs) layer. The resulting composites exhibit a low density of (0.62–0.96 g cm −3 ) but excellent oxidation and ablation resistance, which can withstand ultrahigh temperatures between 2100 °C and 2500 °C. The porous C f /CAs layer, with a density of 0.38 g cm −3 and specific bending and compressive strengths of 43.47 MPa/(g cm −3 ) and 15.53 MPa/(g cm −3 ), respectively, provides both structural integrity and lightweight properties to the C f /ZrB 2 -SiC composite. Furthermore, the density of the composites can be precisely tailored by adjusting the thickness of the C f /ZrB 2 -SiC layer, allowing for customized fabrication to meet diverse service environment requirements. This flexibility highlights the adaptability of the combined processing techniques. The unique combination of controllable low-density properties and exceptional oxidation and ablation resistance endows gradient lightweight C f /ZrB 2 -SiC composites are promising as lightweight, ultra-high temperature thermal protection systems for hypersonic vehicle applications.

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Comparison of ablative and compressive mechanical behavior of several PICA-like ablative materials

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science China(Technological sciences) 2020年第8期63卷 1478-1486页

作者： ZHANG Jun FANG GuoDong YANG LingWei LI Wei HONG ChangQing MENG SongHe National Key Laboratory of Science and Technology for Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

It is significant to compare the ablative and compressive mechanical behavior of different PICA-like materials in the engineering *** plasma wind tunnel ablation tests with high-entropy air and CO2 atmospheres,and compressive experiments in the ambient and 150℃,were conducted for three kinds of PICA-like materials(CF/PR-Si,CBCF/PR-SiOC and NQF/PR-Si composites).The traditional carbon/phenolic(C/PR)braided composites were also used for ***-like materials have the better thermal insulation than traditional C/PR composite,especially for CBCF/PR-SiOC *** ablation behavior of CF/PR-Si and CBCF/PR-SiOC PICA-like materials in the CO2 atmosphere can produce a large amount of SiO2 in the form of coatings,oxide layers and skeletons on the ablated surface,which are greatly different from that in the air *** compressive behavior of PICA-like material is greatly depended on the fiber fabrics,and exhibits the large discrete *** longer fiber in the PICA-like materials plays the role in maintaining the material integrity,while it may increase the thermal conductivity.

关键词： PICA-like material ablation property plasma wind tunnel compressive behavior

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Rashba-like spin splitting around non-time-reversal-invariant momenta

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Physical Review B 2023年第23期107卷 235138-235138页

作者： L. L. Tao Jiayu Li Yuntian Liu Xianjie Wang Yu Sui Bo Song M. Ye. Zhuravlev Qihang Liu School of Physics Harbin Institute of Technology Harbin 150001 China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology Shenzhen 518055 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150001 China St. Petersburg State University St. Petersburg 190000 Russia

The ubiquitous Rashba spin splitting occurring around time-reversal-invariant momenta (TRIM) reflects the fundamental interplay between spin-orbit coupling (SOC) and crystalline symmetry. Unexpectedly, recent measurements reveal novel Rashba spin splitting around the momenta lacking time-reversal symmetry (non-TRIM), whose mechanism remains elusive. Here, we theoretically elucidate the microscopic origin of Rashba spin splitting around non-TRIM and identify the design principles for its appearance. Conventionally, a Zeeman-like spin splitting dominates around non-TRIM due to the broken time-reversal symmetry and diminishes the Rashba-like features. Our results show that the Bloch wave function with specific orbital representation at certain non-TRIM could eliminate the first-order SOC effect. As a result, the corresponding little group hosts a type of quasisymmetry that commutes with the dominating SOC Hamiltonian, leading to a tiny SOC gap and helical spin texture. Furthermore, such a quasi-symmetry-induced tiny gap could manifest large Berry curvature, which is desirable for various topological applications. Our work expands the concept of Rashba physics beyond the conventional TRIM scenario, paving an avenue for designing novel spin-splitting materials through the cooperation of symmetry and orbital engineering.

关键词： Crystal symmetry Rashba coupling Spin-orbit coupling Interfaces Density functional calculations

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Modified radius-weighted lattice Boltzmann model to address singularities in axisymmetric multiphase flows

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Physical Review E 2022年第2期106卷 025316-025316页

作者： Xingchun Xu Yanwei Hu Yurong He Jiecai Han Jiaqi Zhu National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150080 China School of Energy Science & Engineering Harbin Institute of Technology Harbin 150001 China Key Laboratory of Micro-systems and Micro-structures Manufacturing Ministry of Education Harbin 150080 China

The radius-weighted lattice Boltzmann model has achieved great success in the simulation of axisymmetric flows. However, severe spurious currents near the axis are observed when this model is extended to simulate axisymmetric multiphase flows. In this study, to determine the origin of this singularity, we conducted a truncation error analysis based on high-order Taylor series expansion and identified the leading error terms through dimensionless analysis. By neglecting the error terms in proportion to the radius, we obtained the final forms of the singular terms in the axisymmetric lattice Boltzmann model. We proposed a modified model by including an additional correction term, to remove the singularity at the third order. We validated the proposed model using numerical tests for flat and spherical interfaces. Results showed that the present modified model reduced the spurious currents near the axis by two orders of magnitude compared with the original model. This modified model also has been successfully applied to predict bubble dynamics in an air-water system. Our numerical results are in excellent agreement with available experimental observations in terms of bubble shapes and terminal velocities.

关键词： Multiphase flows Lattice-Boltzmann methods Navier-Stokes equation

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Bioinspired Multi-Stimulus Responsive Mxene-Based Soft Actuator with Self-Sensing Function and Various Biomimetic Locomotion

SSRN

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SSRN 2023年

作者： Xu, Liangliang Zheng, Haowen Xue, Fuhua Ji, Qixiao Qiu, Changwen Yan, Qian Ding, Renjie Zhao, Xu Hu, Ying Peng, Qingyu He, Xiaodong National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Center for Composite Materials and Structures Harbin Institute of Technology Harbin150080 China Institute of Industry and Equipment Technology Hefei University of Technology Hefei230009 China

Although a series of outstanding achievements have been realized so far, developing soft actuators that can respond to various stimuli and simulate biological versatility (e.g., self-sensing function, diverse locomotion, etc.) is still a great challenge. Here, by utilizing internal stress generated spontaneously during the preparation process, an originally rolled MXene/polydimethylsiloxane (PDMS) bimorph soft actuator has been designed and fabricated. Based on the outstanding photothermal/electrothermal conversion efficiency and adjustable interlayer d-spacing change of Ti3C2Tx MXene, and the large thermal/chemical vapor expansion of crosslinked PDMS, this actuator can produce reversible large deformation under various forms of stimulus, including heat, light, electric, and n-hexane vapor. More importantly, microcracks can be formed spontaneously on the surface of MXene layer during the fabrication process of the actuator, which causes the resistance of MXene layer to be very sensitive to mechanical deformation. Based on this, a light-driven artificial tongue is fabricated, which not only mimic the ejection motion and catching prey behavior of the frog’s tongue, but also perceive the touching object. Moreover, a series of sophisticated biomimetic locomotion such as jumping, crawling, and self-oscillation all can be realized by using this soft actuator. Besides, the actuator with rolled initial structure can also be an intelligent gripper with low energy consumption. By doping Fe3O4 nanoparticles in PDMS matrix, the composite actuator can carry object to through complex maze in adjustable magnetic field without additional stimulation. This MXene-based actuator provides new insights in design of next generation of smart actuators with multi-functions and multiform motions. © 2023, The Authors. All rights reserved.

关键词： Magnetite

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A Meso-Scale Fem-Sph Adaptive Model and Simulations of Fabric Under Hypervelocity Impact

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SSRN 2023年

作者： Xu, Huadong Zhou, Jia Cao, Xu Yu, Dong Miao, Changqing National Key Laboratory of Science and Technology on Advanced Composites in Special Environment Harbin Institute of Technology Harbin150001 China School of Water Conservancy & Civil Engineering Northeast Agricultural University Harbin150001 China School of Mechanical and Electrical Engineering Harbin Institute of Technology Harbin150001 China

A meso-scale FEM-SPH adaptive model for fabric is developed to simulate hypervelocity impact (HVI) response between multiple fabrics and projectile. An anisotropic elastic-plastic constitutive equation coupled with the Mie-Grüneisen equation of state (EOS) is adopted to describe deviatoric deformation and strongly nonlinear volumetric compression induced by HVI. Considering the interaction of fabric with hierarchical structure and the evolution of impact-induce fragments, a meso-scale FEM-SPH adaptive mesh was created for woven fabrics by finite element-smoothed particle hydrodynamics (FEM-SPH) adaptive method. The meso-scale mesh involves modeling the fabric using a fiber bundles level architecture around the impact region and a yarn level architecture at far field regions. The proposed numerical model is validated by comparing to damaged morphologies and shielding performance of fabric specimens from HVI experiments at different impact velocity. The simulation results are compared with the Lagrangian FEM model, and the results show that the FEM-SPH adaptive method has better prediction ability for the movement and diffusion of impact-induced debris clouds. In addition, the yarn partition sensitivity analysis by difference meso-scale fabric model demonstrates that the agreement of the simulation and experimental results increases with the increasing of the number of fiber bundles in the yarn cross-section, and further indicate that the meso-scale model developed in this paper for fabric has a good capacity for describing the essential details of fibers bundles/yarns in fabric during HVI. © 2023, The Authors. All rights reserved.

关键词： Yarn

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受水车启发的、在饱和盐水中也能实现高效和稳定的太阳能淡化的旋转蒸发器

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science Bulletin 2023年第15期68卷 1640-1650,M0004页

作者：蒋函锦刘行航王海涛王德文郭亚楠王冬高岗王笑夷胡超权 State Key Laboratory of Superhard Materials Key Laboratory of Automobile Materials of Ministry of EducationJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsSchool of Materials Science and EngineeringJilin UniversityChangchun 130012China School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China College of Chemical Engineering Northeast Electric Power UniversityJilin 132012China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Key Laboratory of Optical System Advanced Manufacturing Technology Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

太阳能海水淡化是解决全球淡水短缺的最有前景方法之一.然而,传统的蒸发体在高盐度海水中遭遇了盐累积带来的蒸发速率下降甚至失效的瓶颈.受古代水车的启发,本文开发了一种自适应旋转蒸发器,其可以在任意浓度的盐水中实现长期高效的太... 详细信息

太阳能海水淡化是解决全球淡水短缺的最有前景方法之一.然而,传统的蒸发体在高盐度海水中遭遇了盐累积带来的蒸发速率下降甚至失效的瓶颈.受古代水车的启发,本文开发了一种自适应旋转蒸发器,其可以在任意浓度的盐水中实现长期高效的太阳能海水淡化.这种蒸发器是一种双硫化物负载的滚筒式生物质炭.借助了木材天然的水传输通道和分层结构,蒸发器具有杰出的水供应和热定位能力.实验和数值模拟表明,归因于其低密度及独特的亲疏水特性,这个蒸发器能够在盐结晶产生的重心偏移下周期性转动以实现自动盐移除.这使得这个蒸发体甚至可以在饱和盐水(26.47%)中,24 h内保持2.8 kg m^(-2)h^(-1)的高蒸发速率,这是过去一直无法实现的.因此,这项概念验证工作展示了一种不受浓度和运行时间限制的、自旋转诱导脱盐的蒸发器.

关键词： Adaptively rotating evaporator Self-removal of salt Waterwheel-inspired Stable solar desalination

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Polarization Multiplexing Graphene-Based Coding Metasurfaces For Flexible Wavefront Manipulation And Polarization of Terahertz Beam

SSRN

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SSRN 2023年

作者： He, Xunjun Lu, Jinliang Jiang, Jiuxing Yao, Yongtao Zhang, Ying School of Electrical and Electronic Engineering Harbin University of Science and Technology Harbin150080 China College of Science Harbin University of Science and Technology Heilongjiang150080 China National key laboratory of science and technology on advanced composites in special environments Harbin Institute of Technology Harbin150080 China

Recently, the wavefront control devices based on terahertz metasurfaces have drawn enormous attention in next-generation (6G) communication applications. Generally, these devices achieve dynamic wavefront control by integrating the metasurfaces with traditional active materials. However, most existing devices suffer from limitations such as single polarization mode of incident waves and intrinsic properties of the active materials, which hinder their developments and applications. To address these challenges, herein, we design graphene-based reflection coding metasurfaces for active wavefront control. The coding meta-atom is composed of a graphene split ring resonator, a dielectric layer, and a metal ground plate. Furthermore, by rotating the coding meta-atom, an independent 2π phase coverage may be obtained for CP or LP illuminations, enabling the polarization multiplexing. Based on the vortex phase profile, a proof-of-concept metasurface (MS-1) is constructed to generate different wavefront responses. By altering the polarization mode of incident waves and Fermi level of coding regions, these wavefronts can be actively switched between a vortex beam, multi-beam, and specular reflection beam. Additionally, according to the parabolic phase profile, another metasurface (MS-2) is developed to create a tunable metalens, allowing for active control over its focusing intensity and focal depth by adjusting the Fermi level of graphene. Therefore, these wavefront-controlled metasurfaces have high capacity and integration due to polarization multiplexing and active modulation, making them highly promising for potential applications in terahertz communications. © 2023, The Authors. All rights reserved.

关键词： Graphene

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Welding Process Parameters and Mechanical Properties of Carbon Fiber-Reinforced Thermoplastic composites: Experimental and Simulation Analysis

SSRN

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SSRN 2024年

作者： Wang, Bing Yu, Lin Li, Menglei Guo, Jiabao Ji, Chunming Hu, Jiqiang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin150001 China Beijing Institute of Astronautical Systems Engineering Beijing100076 China AVIC Jonhon Optoelectronics Technology Co. Ltd. Luoyang471000 China

Based on the fusible welding characteristic of thermoplastic composites, this paper develops a resistance welding apparatus to investigate the influence of welding parameters on welding performance and determine optimal welding parameters. To apply numerical simulation to study the mechanical properties of welded composite structures, we propose a multiscale model that combines experiments and micromechanical models. The experiments provide the normal fracture toughness and the tangential mechanical properties of the welds, while the micromechanical model based on the fast Fourier transform (FFT) method and the phase field method (PFM) provides the normal strength of the welds, and cohesive elements are used to simulate the welds. The correctness of the results calculated by the proposed multiscale model is verified based on double cantilever beam (DCB) experiments and T-joint structures. And further investigating the influence of laminate thickness on DCB performance and the failure mechanism of T-joints under bending loads based on this multiscale model. © 2024, The Authors. All rights reserved.

关键词： Welds

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PolarBEVU: Multi-Camera 3D Object Detection in Polar Bird's-Eye View via Unprojection

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IEEE Transactions on Circuits and Systems for Video technology 2025年

作者： Hou, Minghui Lyu, Chuanhao Wang, Gang Ma, Baorui Xu, Rongtao Hu, Jue Fan, Xiaopeng Jilin University College of Computer Science and Technology Changchun China Tsinghua University School of Software Beijing China Chinese Academy of Sciences State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of Automation Beijing China Harbin Institute of Technology National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin150080 China Harbin Institute of Technology Centre for Composite Materials and Structures Harbin150001 China Harbin Institute of Technology Faculty of Computing Harbin150001 China

3D object detection from a Bird's Eye View (BEV) has emerged as a novel perception paradigm for autonomous driving scenarios. While most current 3D object detection methods still rely on the conventional Cartesian coordinates, they fail to align with the non-aligned coordinate system inherent in image geometry. The Polar coordinates, on the other hand, better fit with the geometric shape corresponding to the perception of cameras. However, transforming between coordinate systems introduces distortions in the perception information, resulting in issues such as "Weak Adaptability to Heatmap Distribution"and "Offset in the Center Point of the Bounding Box."To address these challenges, this paper proposes a cutting-edge 3D object detection model named PolarBEVU, which leverages the bird's-eye view under the Polar coordinates along with multi-camera unprojection. The model introduces an innovative "Deformable Uniform Heatmap Distribution"method that adjusts heatmap computations based on box shapes, generating high-quality heatmaps and effectively resolving the issue of "Weak Adaptability to Heatmap Distribution."Moreover, the model incorporates the concept of "Dynamic High-risk Regression Region"to enhance the accuracy and robustness of the center point regression at the bounding box, thus mitigating the issue of "Offset in the Center Point of the Bounding Box."In extensive experiments on the nuScenes dataset, PolarBEVU achieves impressive results with 49.9% mAP and 57.4% NDS on the test set, surpassing other comparative approaches and reaching the state-of-the-art (SOTA) performance among methods utilizing Polar coordinates. This clearly demonstrates the efficacy and superiority of PolarBEVU. In addition, the model is successfully deployed on Nvidia Jetson AGX Orin, showcasing real-time inference speeds of 31.42ms. These findings affirm PolarBEVU's potential for practical applications. Code is available at https: //***/JLUrob/PolarBEVU. © 2025 IEEE.

关键词： Object tracking

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