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Autonomous aeroamphibious invisibility cloak with stochastic-evolution learning

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Advanced Photonics 2024年第1期6卷 64-72页

作者： Chao Qian Yuetian Jia Zhedong Wang Jieting Chen Pujing Lin Xiaoyue Zhu Erping Li Hongsheng Chen zhejiang University ZJU-UIUC InstituteInterdisciplinary Center for Quantum InformationState Key Laboratory of Extreme Photonics and InstrumentationHangzhouChina zhejiang University ZJU-Hangzhou Global Science and Technology Innovation CenterKey Laboratory of Advanced Micro/Nano Electronic Devices and Smart Systems of ZhejiangHangzhouChina zhejiang University Jinhua Institute of Zhejiang UniversityJinhuaChina

Being invisible ad libitum has long captivated the popular imagination,particularly in terms of safeguarding modern high-end instruments from potential *** ago,the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks,which have been mainly demonstrated in ground and waveguide ***,an omnidirectional flying cloak has not been achieved,primarily due to the challenges associated with dynamic synthesis of metasurface *** demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception,decision,and execution modules,capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external *** physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency *** intelligently control the spatiotemporal metasurfaces,we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic *** a fully self-driving experiment,we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes-sea,land,and air-with a similarity rate of up to 95%.Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.

关键词： intelligent metasurfaces optical materials and structures deep learning

Non-uniform thermal behavior of single-layer spherical reticulated shell structures considering time-variant environmental factors: analysis and design

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Journal of zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 223-237页

作者： Wucheng XU Xiaoqing ZHENG Xuanhe ZHANG Zhejie LAI Yanbin SHEN College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China center for Balance Architecture Zhejiang UniversityHangzhou 310028China Innovation center of Yangtze River Delta Zhejiang UniversityJiaxing 314100China zhejiang Provincial Key laboratory of Space Structures Zhejiang UniversityHangzhou 310058China

Contrary to conventional design methods that assume uniform and slow temperature changes tied to atmospheric conditions,single-layer spherical reticulated shells undergo significant non-uniform and time-variant temperature variations due to dynamic environmental *** differences can affect structural performance and pose safety ***,a systematic numerical method was developed and applied to simulate long-term temperature variations in such a structure under real environmental conditions,revealing its non-uniform distribution characteristics and time-variant regularity.A simplified design method for non-uniform thermal loads,accounting for time-variant environmental factors,was theoretically derived and validated through experiments and *** maximum deviation and mean error rate between calculated and tested results were 6.1℃ and 3.7%,*** temperature fields aligned with simulated ones,with deviations under 6.0℃.Using the design method,non-uniform thermal effects of the structure are *** member stress and nodal displacement under non-uniform thermal loads reached 119.3 MPa and 19.7 mm,representing increases of 167.5%and 169.9%,respectively,compared to uniform thermal *** impacts of healing construction time on non-uniform thermal effects were evaluated,resulting in construction *** methodologies and conclusions presented here can serve as valuable references for the thermal design,construction,and control of single-layer spherical reticulated shells or similar structures.

关键词： Non-uniform temperature field Non-uniform thermal load Non-uniform thermal effect Single-layer spherical reticulated shell Time-variant environmental factor

Full-parameter omnidirectional transformation optical devices

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National Science Review 2024年第3期11卷 92-99页

作者： Yuan Gao Yu Luo Jingjing Zhang Zhengjie Huang Bin Zheng Hongsheng Chen Dexin Ye Interdisciplinary center for Quantum Information State Key Laboratory of Extreme Photonics and InstrumentationZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang University School of Electrical and Electronic Engineering Nanyang Technological University CNRS-InternationalNTU-Thales Research Alliance Nanyang Technological University Institute of Electromagnetic Space Southeast University State Key laboratory of Millimeter Waves Southeast University International Joint Innovation center The Electromagnetics Academy at Zhejiang University Zhejiang University Key laboratory of Advanced Micro/Nano Electronic Devices&Smart Systems of zhejiang Jinhua Institute of Zhejiang UniversityZhejiang University Shaoxing Institute of zhejiang University Zhejiang University

Transformation optics(TO) provides an unprecedented technique to control electromagnetic(EM) waves by engineering the constitutive parameters of the surrounding medium through a proper spatial transformation. In general, ideal transformation optical devices require simultaneous electric and magnetic responses along all three dimensions. To ease the practical implementation, previous studies usually made use of reduced parameters or other simplified approaches, which inevitably introduce extra reflection or unwanted phase shift. Up to today, experimental realizations of full-parameter transformation optical devices in free space are still quite limited. Here, a general design strategy is proposed to solve this *** a specific example, a full-parameter spatial-compression TO medium with constitutive parameters taking the diagonal form diag(a, a, 1/a) for the TM wave incidence was designed and realized experimentally. Such spatial-compression TO media were then applied to the implementation of an ideal omnidirectional invisibility cloak capable of concealing a large-scale object over a wide range of illumination angles. Both the simulation and experiment confirm that the cloak allows for nearly unity transmission of EM waves in the forward direction without introducing extra scattering or phase shift. This work constitutes an important stepping stone for future practical implementation of arbitrary full-parameter omnidirectional transformation optical devices.

关键词： transformation optical devices omnidirectional impedance matching full-parameter invisibility cloak

MicroRNA-146a-loaded magnesium silicate nanospheres promote bone regeneration in an inflammatory microenvironment

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Bone Research 2024年第1期12卷 153-164页

作者： Jiakang Yang Jing Shuai Lixuen Siow Jingyi Lu Miao Sun Wenyue An Mengfei Yu Baixiang Wang Qianming Chen Stomatology Hospital School of StomatologyZhejiang University School of MedicineZhejiang Provincial Clinical Research Center for Oral DiseasesKey Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhou 310000China

Reconstruction of irregular oral-maxillofacial bone defects with an inflammatory microenvironment remains a challenge,as chronic local inflammation can largely impair bone ***,we used magnesium silicate nanospheres(MSNs)to load microRNA-146a-5p(miR-146a)to fabricate a nanobiomaterial,MSN+miR-146a,which showed synergistic promoting effects on the osteogenic differentiation of human dental pulp stem cells(hDPSCs).In addition,miR-146a exhibited an anti-inflammatory effect on mouse bone marrow-derived macrophages(BMMs)under lipopolysaccharide(LPS)stimulation by inhibiting the NF-κB pathway via targeting tumor necrosis factor receptor-associated factor 6(TRAF6),and MSNs could simultaneously promote M2 polarization of ***-146a was also found to inhibit osteoclast ***,the dual osteogenic-promoting and immunoregulatory effects of MSN+miR-146a were further validated in a stimulated infected mouse mandibular bone defect model via delivery by a photocuring ***,the MSN+miR-146a complex revealed good potential in treating inflammatory irregular oralmaxillofacial bone defects.

关键词： inflammatory healing stimulation

Clinical relevance of distolingual roots and periodontal status in mandibular first molars: a cross-sectional study employing CBCT analysis

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Journal of zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第3期25卷 244-253页

作者： Feifei MAO Meng WANG Shuai ZHOU Yan ZHAO Jiaping HUANG Fengying YIN Haiping YANG Pei-hui DING Stomatology Hospital School of StomatologyZhejiang University School of MedicineZhejiang Provincial Clinical Research Center for Oral DiseasesKey Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhou 310016China

Objectives:Distolingual root of the permanent mandibular first molar(PMFM-DLR)has been frequently reported,which may complicate the treatment of *** study aimed to assess the morphological features of PMFM-DLR and investigate the correlation between the morphological features of PMFM-DLR and periodontal status in patients with Eastern Chinese ethnic *** and methods:A total of 836 cone beam computed tomography(CBCT)images with 1497 mandibular first molars were analyzed to observe the prevalence of PMFM-DLR at the patients and tooth levels in Eastern *** them,complete periodontal charts were available for 69 Chinese patients with 103 *** and regression analyses were used to evaluate the correlation between the morphological features of DLR,bone loss,and periodontal clinical parameters,including clinical attachment loss(CAL),probing pocket depth(PPD),gingival recession(GR),and furcation involvement(FI).Results:The patient-level prevalence and tooth-level prevalence of DLR in mandibular first molars were 29.4%and 26.3%,*** linear regression analysis suggested that bone loss at the lingual site and CAL were negatively affected by the angle of separation between distolingual and mesial roots in the transverse section,while they were significantly influenced by age and the angle of separation between distobuccal and mesial roots in the coronal ***:The prevalence of PMFM-DLR in Eastern China was relatively high in our *** morphological features of DLR were correlated with the periodontal status of mandibular first *** study provides critical information on the morphological features of DLR for improved diagnosis and treatment options of mandibular molars with DLR.

关键词： Distolingual root Mandibular first molar Periodontal clinical parameter Clinical attachment loss Cone beam computed tomography(CBCT)

Ultra-high extinction ratio optical pulse generation with a thin film lithium niobate modulator for distributed acoustic sensing

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Photonics Research 2024年第1期12卷 40-50页

作者： YUAN SHEN XIAOQIAN SHU LINGMEI MA SHAOLIANG YU GENGXIN CHEN LIU LIU RENYOU GE BIGENG CHEN YUNJIANG RAO Research center for Optical Fiber Sensing Zhejiang LaboratoryHangzhou 311100China Research center for Intelligent Optoelectronic Computing Zhejiang LaboratoryHangzhou 311100China International Research center for Advanced Photonics College of Optical Science and EngineeringZhejiang UniversityHangzhou 310058China Fiber Optics Research center(FORC) Key Laboratory of Optical Fiber Sensing and CommunicationsUniversity of Electronic Science and Technology of ChinaChengdu 611731China

We experimentally demonstrate ultra-high extinction ratio(ER)optical pulse modulation with an electro-optical modulator(EOM)on thin film lithium niobate(TFLN)and its application for fiber optic distributed acoustic sensing(DAS).An interface carrier effect leading to a relaxation-tail response of TFLN EOM is discovered,which can be well addressed by a small compensation component following the main driving *** ultrahigh ER>50 dB is achieved by canceling out the tailed response during pulse modulation using the EOM based on a cascaded Mach–Zehnder interferometer(MZI)*** modulated optical_(√)pulses are then utilized as a probe light for a DAS system,showing a sensitivity up to-62.9 dB·rad∕Hz~2(7 pε/Hz)for 2-km single-mode sensing *** crosstalk suppression of 24.9 dB along the fiber is also obtained when the ER is improved from 20 dB to 50 dB,clearly revealing its importance to the sensing performance.

关键词： modulator pulse interferometer

A spaceborne advanced storage system for remote sensing microsatellites

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 600-615页

作者： Shilei TU Huiquan WANG Yue HUANG Zhonghe JIN Micro-Satellite Research center Zhejiang UniversityHangzhou 310027China Key laboratory of Micro-Nano Satellite Research Zhejiang ProvinceHangzhou 310027China

With the development of satellite miniaturization and remote sensing,the establishment of microsatellite constellations is an inevitable *** to their limited size,weight,and power,spaceborne storage systems with excellent scalability,performance,and reliability are still one of the technical bottlenecks of remote sensing *** on the commercial off-the-shelf field-programmable gate array and memory devices,a spaceborne advanced storage system(SASS)is proposed in this *** work provides a dynamic programming,queue scheduling multiple-input multiple-output cache technique and a high-speed,high-reliability NAND flash controller for multiple microsatellite payload *** results show that SASS has outstanding scalability with a maximum write rate of 2429 Mb/s and preserves at least 78.53%of the performance when a single NAND flash *** scheduling technique effectively shortens the data scheduling time,and the data remapping method of the NAND flash controller can reduce the retention error by at least 50.73%and the program disturbance error by at least 37.80%.

关键词： Microsatellite Spaceborne advanced storage system(SASS) Scalability Performance Reliability

Yangtze River Delta Aerosol liquid water in PM_(2.5)and its roles in secondary aerosol formation at a regional site of Yangtze River Delta

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Journal of Environmental Sciences 2024年第4期138卷 684-696页

作者： Ruifang Shi Fei Zhang Yemin Shen Jiasi Shen Bingye Xu Binyu Kuang Zhengning Xu Lingling Jin Qian Tang Xudong Tian Zhibin Wang College of Environmental and Resource Sciences Zhejiang Provincial Key Laboratory of Organic Pollution Process and ControlZhejiang UniversityHangzhou 310058China ZJU-Hangzhou Global Scientific and Technological Innovation center Zhejiang UniversityHangzhou 311215China zhejiang Ecological and Environmental Monitoring center Hangzhou 310012China

Aerosol liquid water content(ALWC)plays an important role in secondary aerosol *** this study,a whole year field campaign was conducted at Shanxi in north zhejiang Province during *** estimated by ISORROPIA-Ⅱ was then investigated to explore its characteristics and relationship with secondary *** exhibited a highest value in spring(66.38μg/m^(3)),followed by winter(45.08μg/m^(3)),summer(41.64μg/m^(3)),and autumn(35.01μg/m^(3)),*** was supposed that the secondary inorganic aerosols(SIA)were facilitated under higher ALWC conditions(RH>80%),while the secondary organic species tended to form under lower ALWC *** RH(>80%)promoted the NO_(3)^(-)formation via gas-particle partitioning,while SO_(4)^(2-)was generated at a relative lower RH(>50%).The ALWC was more sensitive to NO_(3)^(-)(R=0.94)than SO_(4)^(2-)(R=0.90).Thus,the self-amplifying processes between the ALWC and SIA enhanced the particle mass *** sensitivity of ALWC and OX(NO_(2)+O_(3))to secondary organic carbon(SOC)varied in different seasons at Shanxi,more sensitive to aqueous-phase reactions(daytime R=0.84;nighttime R=0.54)than photochemical oxidation(daytime R=0.23;nighttime R=0.41)in wintertime with a high level of OX(daytime:130-140μg/m^(3);nighttime:100-140μg/m^(3)).The self-amplifying process of ALWC and SIA and the aqueous-phase formation of SOC will enhance aerosol formation,contributing to air pollution and reduction of visibility.

关键词： Aerosol liquid water content Nitrate Sulfate Secondary organic compounds Aqueous-phase reaction

Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin

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Chinese Journal of Chemical Engineering 2024年第3期67卷 135-147页

作者： Congjing Ren Peng Zhang Qi Song Zhengliang Huang Yao Yang Yongrong Yang Ningbo Innovation center Zhejiang UniversityNingbo 315100China College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China

This work investigated the pyrolysis reaction of waste resin in a fluidized bed *** was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and *** kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical *** the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of *** the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

关键词： Pyrolysis reaction of waste resin Fluidization Particle agglomeration Kaolin