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Mode crossing induced soliton frequency comb generation in high-Q yttria-stabilized zirconia crystalline optical microresonators

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Photonics Research 2022年第3期10卷 731-739页

作者： Guoping Lin Tang Sun Ministry of Industry and Information Technology Key Laboratory of Micro-Nano Optoelectronic Information System School of ScienceHarbin Institute of TechnologyShenzhen 518055China Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We demonstrate for the first time,to the best of our knowledge,the fabrication of high-Q crystalline optical microresonators from cubic yttria-stabilized zirconia(YSZ).Intrinsic Q factors up to 80 million are obtained,indicating an upper bound absorption coefficient of 0.001cm^(−1) for YSZ crystals at the telecom *** laser-scanned spectroscopy on a few-mode YSZ microresonator with a radius of 300μm,we find that the mode crossing effect in the case of weak coupling can induce a repelling disruption of free spectral range values between transverse mode *** of soliton and soliton crystals in such a YSZ microcomb platform operated in the normal dispersion regime is observed.A breathing comb behavior is also *** finding has enriched comb generation platforms with potential multidisciplinary capabilities linked to properties of YSZ crystals in superconducting films and sensors.

关键词： crystalline soliton mode

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Modelling and experimental investigation of frequency splitting of hemispherical resonator with machining errors

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Chinese Journal of Aeronautics 2025年

作者： Chuanzhen MA Henan LIU Jian CHENG Mingjun CHEN State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Zhengzhou Research Institute Harbin Institute of Technology Zhengzhou 450000 China

Hemispherical Resonator (HSR) is a typical high-performance component due to the complex coupling relationship between the machining errors and performance parameters. To understand the impact of machining errors on frequency splitting, the frequency splitting model that couples the multiple machining errors was developed to elucidate the mechanism of frequency splitting and reveal the effect of geometric error parameters on frequency splitting innovatively. In addition, a method for characterizing machining errors is established to describe the circumferential mass uniformity of the hemispherical shell. Furthermore, measurement experiments of HSRs were performed to verify the accuracy of the model, and the results showed that the predicted errors of the model were within 15%. Both theoretical and experimental results demonstrated that the direct cause of frequency splitting is the uneven circumferential mass of HSR. In particular, the radial concentricity has the most significant influence on frequency splitting, followed by the coaxiality and roundness. Within the error range of 0-0.5 μm, frequency splitting values change by 0.945 Hz, 0.098 Hz, and 0.039 Hz, respectively. Furthermore, the coupling effect of machining errors and surface quality on frequency splitting was discussed, which showed machining errors is the predominant factor contributing to frequency splitting. This work not only enhance the understanding of the mechanism of frequency splitting, but also provide theoretical guidance for the parameter optimization involved in high-performance manufacturing of HSR.

关键词： Hemispherical resonator Frequency splitting Mass nonuniformity Machining errors Surface quality

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World’s first spaceflight on-orbit demonstration of a flexible solar array system based on shape memory polymer composites

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Science China(Technological Sciences) 2020年第8期63卷 1436-1451页

作者： LAN Xin LIU LiWu ZHANG FengHua LIU ZhengXian WANG LinLin LI QiFeng PENG Fan HAO SiDa DAI WenXu WAN Xue TANG Yong WANG Mian HAO YanYan YANG Yang YANG Cheng LIU YanJu LENG JinSong Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150080China Department of Aerospace Science and Mechanics Harbin Institute of TechnologyHarbin 150001China Institute of Telecommunication Satellite China Academy of Space TechnologyBeijing 100094China State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power-SourcesShanghai 200245China

With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing *** this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit *** epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar *** releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 *** systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling *** locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,*** SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary *** triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon *** study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.

关键词： shape memory polymer composite releasing mechanism shape memory polymer composite tubes flexible solar array

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Referencing where to focus: improving visual grounding with referential query 24

Referencing where to focus: improving visual grounding with ...

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Proceedings of the 38th International Conference on Neural Information Processing systems

作者： Yabing Wang Zhuotao Tian Qingpei Guo Zheng Qin Sanping Zhou Ming Yang Le Wang National Key Laboratory of Human-Machine Hybrid Augmented Intelligence National Engineering Research Center for Visual Information and Applications and Institute of Artificial Intelligence and Robotics Xi'an Jiaotong University Harbin Institute of Technology Shenzhen China AntGroup

ISBN: (纸本)9798331314385

Visual Grounding aims to localize the referring object in an image given a natural language expression. Recent advancements in DETR-based visual grounding methods have attracted considerable attention, as they directly predict the coordinates of the target object without relying on additional efforts, such as pre-generated proposal candidates or pre-defined anchor boxes. However, existing research primarily focuses on designing stronger multi-modal decoder, which typically generates learnable queries by random initialization or by using linguistic embeddings. This vanilla query generation approach inevitably increases the learning difficulty for the model, as it does not involve any target-related information at the beginning of decoding. Furthermore, they only use the deepest image feature during the query learning process, overlooking the importance of features from other levels. To address these issues, we propose a novel approach, called RefFormer. It consists of the query adaption module that can be seamlessly integrated into CLIP and generate the referential query to provide the prior context for decoder, along with a task-specific decoder. By incorporating the referential query into the decoder, we can effectively mitigate the learning difficulty of the decoder, and accurately concentrate on the target object. Additionally, our proposed query adaption module can also act as an adapter, preserving the rich knowledge within CLIP without the need to tune the parameters of the backbone network. Extensive experiments demonstrate the effectiveness and efficiency of our proposed method, outperforming state-of-the-art approaches on five visual grounding benchmarks.

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SpringExo, a spring-based exoskeleton for providing knee assistance: Design, Characterization and Feasibility Study

SpringExo, a spring-based exoskeleton for providing knee ass...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Dongbao Sui Biing-Chwen Chang Rand Hidayah Yanhe Zhu Sunil K. Agrawal State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China Columbia University New York NY USA

This paper presents the design and preliminary evaluation of a portable spring-based knee exoskeleton, the SpringExo, which is designed to provide assistance to the leg while minimizing interference with the natural leg movement. Traditional rigid exoskeletons are unable to accurately align with a user’s anatomical joints. In addition, the user’s natural motion pattern is likely to change due to the constraints of the rigid exoskeleton. Though some textile-based soft exosuits and cable-driven soft exoskeletons have been developed to achieve better alignment with human’s biological joints, forces applied by the cables have to be sustained by human skeleton and joints. SpringExo, in comparison, uses a coil spring which the user wears around the thigh and shank, and does not require alignment with the joints. The spring stores energy and provides minimal interference during elastic deformation. A key feature of the SpringExo is that the springs store energy during the flexion phase and release this energy to assist the knee extension in the extension phase. We conducted human subjects study to verify its biomechanical and physiological effects on the user during stair ascent. Results from a six-subject study showed that the device did not interfere with the natural joint angles and assisted knee extension during stair ascent. However, further redesign and optimization are needed on the actuation system to offset SpringExo’s drawback of hindering knee flexion.

关键词： Knee Legged locomotion Exoskeletons Thigh Interference Stairs Skeleton

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Lensless camera: Unraveling the breakthroughs and prospects

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Fundamental Research 2024年

作者： Li, Shuowen Gao, Yunhui Wu, Jiachen Wang, Mingjie Huang, Zhangcheng Chen, Shumei Cao, Liangcai Department of Precision Instruments Tsinghua University Beijing 100084 China Key Laboratory of Micro-Nano Optoelectronic Information System of Ministry of Industry and Information Technology Harbin Institute of Technology Shenzhen 518055 China State Key Laboratory of ASIC and System Frontier Institute of Chip and System Fudan University Shanghai 200438 China

Lensless imaging is an innovative and swiftly advancing technology at the intersection of optics, imaging technology, and computational science. It captures scene by directly recording the interference or diffraction patterns of light, subsequently utilizing algorithms to reconstruct the original image from these patterns. Lensless imaging transforms traditional imaging paradigms, offering newfound design flexibility and the capacity to seamlessly integrate within diverse imaging ecosystems. This paper aims to provide an overview of significant developments in optical modulation elements, image sensors, and reconstruction algorithms. The novel application scenarios that benefit from lensless computational imaging are presented. The opportunities and challenges associated with lensless camera are discussed for further improving its performance. © 2024

关键词： Coded aperture imaging Compressive sensing Deep learning Lensless camera Metasurface

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Ultraclean Surface of Garnet-Type Electrolyte Enables Low Interfacial Resistance in Solid-state Lithium Batteries

SSRN

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SSRN 2022年

作者： Qin, Zhiwei Xie, Yuming Meng, Xiangchen Qian, Delai Shan, Cheng Mao, Dongxin He, Gang Zheng, Zhen Wan, Long Huang, Yongxian X. State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin150001 China Center for Analysis Measurement and Computing Harbin Institute of Technology Harbin150001 China

Solid-state lithium batteries (SSLBs) with garnet-type Li6.5La3Zr1.5Ta 0.5O12 (LLZTO) are one of the most promising candidates for next-generation energy storage system due to their high safety and high stability against Li metal. However, the poor interfacial contact of Li/LLZTO interface induced by Li2CO3 surface impurity hinders its practical application. Herein, we propose an environmental friendliness and convenient high-speed mechanical polishing (HMP) method to remove impurities on porous LLZTO surface and retrieve its lithiophilicity. The strong centrifugal force provided by the high rotation speed promotes the complete removal of Li2CO3 impurity and accelerates the Li-ion transport at Li/LLZTO interface, reducing the interfacial resistance to 28.15 Ω·cm 2 under ultraclean interface, which is comparable to the state-of-the-art surface treatments. Symmetric Li cells assembled with high-speed (5000 rpm) polished LLZTO exhibit a critical current density of 1.91 mA·cm-2 and excellent cycling stability for 1200 h at 0.1 mA·cm-2. SSLBs with LiFePO 4 cathode achieve a superior stable cycling performance with a high discharge capacity of 138.6 mA·h·g-1 and a capacity retention of 89.5% after 500 cycles (0.2 C). This work guides a new understanding for obtaining lithiophilic Li/LLZTO interface through a simple, low-cost and high-efficient polishing strategy, which is potentially utilized for large-scale industrial production of SSLBs. © 2022, The Authors. All rights reserved.

关键词： Solid electrolytes

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Design of deployable bridge using multistable miura-ori structure for emergency rescue

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Automation in Construction 2025年 176卷

作者： Wang, Wei Li, Xu Yan, Peng Huang, Hailin Li, Bing School of Robotics and Advanced Manufacture Harbin Institute of Technology Shenzhen518052 China Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Shenzhen518052 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

Rapid deployment equipment is crucial in emergency rescue operations during natural disasters such as earthquakes and floods. However, traditional equipment often has limitations such as complex operations, long deployment times, and high manpower requirements. This paper designs a deployable bridge for post-disaster rescue, with its core component being a bistable Miura-ori unit. Bistable characteristics of the Miura-ori unit are shown. Then, finite element model (FEM) and prototype experiments are used to demonstrate the load-bearing capacity and bistable characteristics of the bistable Miura-ori unit. By arranging the bistable Miura-ori units, a deployable bridge with multistable characteristics is achieved, enabling rapid deployment with a single drive. The load-bearing and impact resistance capabilities of the bridge are also tested. This design significantly simplifies system complexity, reduces labor requirements, and ensures high load-bearing capacity and impact resistance, providing a new solution for emergency rescue. © 2025 Elsevier B.V.

关键词： Emergency services

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Interface Engineering for Garnet-Type Electrolyte Enables Low Interfacial Resistance in Solid-state Lithium Batteries

SSRN

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SSRN 2022年

作者： Qin, Zhiwei Xie, Yuming Meng, Xiangchen Qian, Delai Shan, Cheng Mao, Dongxin He, Gang Zheng, Zhen Wan, Long Huang, Yongxian State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin150001 China Center for Analysis Measurement and Computing Harbin Institute of Technology Harbin150001 China

Solid-state lithium batteries (SSLBs) with garnet-type Li6.5La3Zr1.5Ta0.5O12 (LLZTO) are one of the most promising candidates for next-generation energy storage system due to their high safety and high stability against Li metal. However, the poor interfacial contact of Li/LLZTO interface induced by Li2CO3 surface impurity hinders its practical application. Herein, interface engineering enabled by high-speed mechanical polishing (HMP) method is proposed to remove impurities on porous LLZTO surface and retrieve its lithiophilicity. The strong centrifugal force provided by the high rotation speed promotes the complete removal of Li2CO3 impurity and accelerates the Li-ion transport at Li/LLZTO interface, reducing the interfacial resistance to 28.15 Ω·cm2 under ultraclean interface, which is comparable to the state-of-the-art surface treatments. Symmetric Li cells assembled with high-speed (5000 rpm) polished LLZTO exhibit a critical current density of 1.91 mA·cm-2 and excellent cycling stability for 1200 h at 0.1 mA·cm-2. SSLBs with LiFePO4 cathode achieve a superior stable cycling performance with a high discharge capacity of 138.6 mA·h·g-1 and a capacity retention of 89.5% after 500 cycles (0.2 C). This work guides a new understanding for obtaining lithiophilic Li/LLZTO interface through a simple, low-cost and high-efficient polishing strategy, which is potentially utilized for large-scale industrial production of SSLBs. © 2022, The Authors. All rights reserved.

关键词： Solid electrolytes

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NNPP: A learning-based heuristic model for accelerating optimal path planning on uneven terrain

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robotics and Autonomous systems 2025年 193卷

作者： Yiming Ji Yang Liu Guanghu Xie Boyu Ma Zongwu Xie Baoshi Cao State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin 150001 Heilongjiang China

Intelligent autonomous path planning is essential for enhancing the exploration efficiency of mobile robots operating in uneven terrains like planetary surfaces and off-road environments. In this paper, we propose the NNPP model for computing the heuristic region, enabling foundation algorithms like A ⋆ to find the optimal path solely within this reduced search space, effectively decreasing the search time. The NNPP model learns semantic information about start and goal locations, as well as map representations, from numerous pre-annotated optimal path demonstrations, and produces a probabilistic distribution over each pixel representing the likelihood of it belonging to an optimal path on the map. More specifically, the paper computes the traversal cost for each grid cell from the slope, roughness and elevation difference obtained from the digital elevation model. Subsequently, the start and goal locations are encoded using a Gaussian distribution and different location encoding parameters are analyzed for their effect on model performance. After training, the NNPP model is able to accelerate path planning on novel maps. Experiments demonstrate that the heuristic region generated by the NNPP model achieves a 3 × speedup for optimal path planning under identical hardware conditions. Moreover, the NNPP model’s advantage becomes more pronounced as the size of the map increases.

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