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Insect Science 2024年第3期31卷 733-747页

作者： Lixian Wu Yajing xu Liangbin Li Dainan Cao fang Liu Hongxia Zhao Guangdong Key Laboratssory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouChina

During the pupal-adult eclosion process of holometabolous insects,the old cuticle is shed and replaced by a completely different new cuticle that requires tanning and expansion,along with extensive extracellular matrix(ECM)*** vertebrates,matrix metalloproteinases(MMPs),a class of zinc-dependent endopeptidases,play key roles in regulating the ECM that surrounds ***,little is known about these extracellular proteinases available in *** small hive beetle(SHB),Aethina tumida,is a widespread invasive parasite of honey *** this study,6 MMP homologs were identified in the SHB *** interference experiments showed that all 6 AtMmps are not required for the larval-pupal transition,only AtMmp2 was essential for pupal-adult eclosion in *** of AtMmp2 resulted in eclosion defects and wing expansion failure,as well as mortality within 3 d of adult *** analysis revealed that knockdown of AtMmp2 significantly increased expression of the Toll and Imd pathways,chitin metabolism,and cross-linking(such as the pro-phenoloxidase activating cascade pathway and the tyrosine-mediated cuticle sclerotization and pigmentation pathway).These data revealed evolutionarily conserved functions of Mmp2 in controlling adult eclosion and wing expansion,also provided a preliminary exploration of the novel function of regulating Toll and Imd pathways,as well as new insights into how MMPs regulate insect development and defense barriers.

关键词： Aethina tumida adult eclosion immune response matrix metalloproteinase RNAinterference

Methanol steam reforming for hydrogen production driven by an atomically precise Cu catalyst

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Green Energy & Environment 2024年第7期9卷 1079-1084页

作者： Weigang Hu Haoqi Liu Yuankun Zhang Jiawei Ji Guangjun Li Xiao Cai xu Liu wen Wu xu Weiping Ding Yan Zhu School of Chemistry and Chemical Engineering Nanjing University School of Physical Science and Technology Ningbo University

Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam *** this work,we report an atomically precise Cu13cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three *** Cu13H10（SR）3（PR’3）7(SR=2,4-dichlorobenzenethiol,PR’3=P（4-FC6H4）3) cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H2production.

关键词： Nanocluster Photocatalysis Methanol steam reforming Atomically precise Copper catalyst

Deep reinforcement learning using least-squares truncated temporal-difference

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 425-439页

作者： Junkai Ren Yixing Lan Xin xu Yichuan Zhang Qiang fang Yujun Zeng College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina State Key Laboratory of Astronautic Dynamics Xi'an Satellite Control CenterXi'anChina

Policy evaluation(PE)is a critical sub-problem in reinforcement learning,which estimates the value function for a given policy and can be used for policy ***,there still exist some limitations in current PE methods,such as low sample efficiency and local convergence,especially on complex *** this study,a novel PE algorithm called Least-Squares Truncated Temporal-Difference learning(LST2D)is *** LST2D,an adaptive truncation mechanism is designed,which effectively takes advantage of the fast convergence property of Least-Squares Temporal Difference learning and the asymptotic convergence property of Temporal Difference learning(TD).Then,two feature pre-training methods are utilised to improve the approximation ability of ***,an Actor-Critic algorithm based on LST2D and pre-trained feature representations(ACLPF)is proposed,where LST2D is integrated into the critic network to improve learning-prediction *** simulation studies were conducted on four robotic tasks,and the corresponding results illustrate the effectiveness of *** proposed ACLPF algorithm outperformed DQN,ACER and PPO in terms of sample efficiency and stability,which demonstrated that LST2D can be applied to online learning control problems by incorporating it into the actor-critic architecture.

关键词： Deep reinforcement learning policy evaluation temporal difference value function approximation

DGConv: A Novel Convolutional Neural Network Approach for Weld Seam Depth Image Detection

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Computers, Materials & Continua 2024年第2期78卷 1755-1771页

作者： Pengchao Li fang xu Jintao Wang Haibing Guo Mingmin Liu Zhenjun Du State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110169China University of Chinese Academy of Sciences Beijing100049China Shenyang SIASUN Robot&Automation Co. Ltd.Shenyang110168China

We propose a novel image segmentation algorithm to tackle the challenge of limited recognition and segmentation performance in identifying welding seam images during robotic intelligent ***,to enhance the capability of deep neural networks in extracting geometric attributes from depth images,we developed a novel deep geometric convolution operator(DGConv).DGConv is utilized to construct a deep local geometric feature extraction module,facilitating a more comprehensive exploration of the intrinsic geometric information within depth ***,we integrate the newly proposed deep geometric feature module with the Fully Convolutional Network(FCN8)to establish a high-performance deep neural network algorithm tailored for depth image ***,we enhance the FCN8 detection head by separating the segmentation and classification *** enhancement significantly boosts the network’s overall detection ***,for a comprehensive assessment of our proposed algorithm and its applicability in real-world industrial settings,we curated a line-scan image dataset featuring weld *** dataset,named the Standardized Linear Depth Profile(SLDP)dataset,was collected from actual industrial sites where autonomous robots are in ***,we conducted experiments utilizing the SLDP dataset,achieving an average accuracy of 92.7%.Our proposed approach exhibited a remarkable performance improvement over the prior method on the identical ***,we have successfully deployed the proposed algorithm in genuine industrial environments,fulfilling the prerequisites of unmanned robot operations.

关键词： Weld image detection deep learning semantic segmentation depth map geometric feature extraction

Experimental Study on Mixed-Mode(Ⅰ–Ⅱ)Fracture Toughness of Freshwater Ice

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Acta Mechanica Solida Sinica 2024年第2期37卷 252-264页

作者： Yaozhong xu Mao Zhou Xian Yi wen Hua Jiuzhou Huang wenyu Zhang Shiming Dong Key Laboratory of Deep Underground Science and Engineering Ministry of EducationCollege of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province Sichuan UniversityChengdu610065China China Aerodynamics Research and Development Center/Low Speed Aerodynamics Research Institute Mianyang621000China College of Mechanical and Electrical Engineering Xichang UniversityXichang615000China

In recent years,the issue of aircraft icing has gained widespread *** breaking and detachment of dynamic ice can pose a threat to flight ***,the shedding and fracture mechanisms of dynamic ice are unclear and cannot meet the engineering needs of ice-shedding hazard ***,studying the fracture toughness of ice bodies has extremely important practical *** address this issue,this article uses a centrally cracked Brazilian disk(CCBD)specimen to measure the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice at different loading *** mixed-mode(Ⅰ–Ⅱ)fracture characteristics of ice are discussed,and the experimental results are compared and analyzed with the theoretical values of the generalized maximum tangential stress(GMTS)criterion considering the influence of *** results indicated that as the loading rate increases,the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice decrease,and the fracture toughness of freshwater ice is more sensitive to the loading rate.Ⅰn terms of fracture criteria,the theoretical value of the ratio of pure modeⅡfracture toughness to pure modeⅠfracture toughness based on the GMTS criterion is in good agreement with the experimental value,while the theoretical value based on the maximum tangential stress(MTS)criterion deviates significantly from the experimental value,indicating that the GMTS criterion considering the influence of T-stress can better predict the experimental results.

关键词： Freshwater ice Fracture criteria Centrally cracked Brazilian disk(CCBD) Mixed-mode(Ⅰ-Ⅱ) Loading rate

Recent advances in bioinspired vision systems with curved imaging structures

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Rare Metals 2024年第4期43卷 1407-1434页

作者： Ze-Ping He xun Han wen-Qiang Wu Zhang-Sheng xu Cao-Feng Pan CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing100049China ZJU-Hangzhou Global Scientific and Technological Innovation Center School of Micro-Nano ElectronicsZhejiang UniversityHangzhou311200China Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen518060China

Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image *** results in a complex and bulky *** contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal *** by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced ***,we review the recent advances in bioinspired vision systems with curved imaging ***,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing *** addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.

关键词： Bioinspired Curved vision system Compound eye Chambered eye Neuromorphic

Abnormal grain growth induced byδ→γphase transformation in Fe-based shape memory alloys

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Journal of Materials Science & Technology 2024年第5期172卷 196-201页

作者： Huabei Peng Liqiu Yong Gaixia Wang Jiazhen Yan Bing xu Yuhua wen School of Mechanical Engineering Sichuan UniversityChengdu 610065China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China

Grain boundaries,including low-angle,high-angle,and coinci-dence boundaries,are intrinsic interfaces in polycrystalline *** heat-treatment at sufficiently high temperatures,grain boundary migration occurs because the grain boundaries are ther-modynamically ***,grain growth occurs due to a decrease in grain boundary area after heat-treatment[1].In general,there are two types of grain growth:normal grain growth,where grains grow uniformly,and abnormal grain growth,where one or a few grains selectively grow and engulf surround-ing smaller grains,leading to the formation of large grains,some-times several millimeters or greater in size[2].The classical tech-nique to achieve abnormal grain growth is the strain-annealing method,which involves subjecting the material to a small strain followed by annealing[3,4].This method has been reported to ob-tain single-crystal wires or plates[1].Additionally,abnormal grain growth can be achieved by plastic straining at high temperatures,resulting in the fabrication of large grains or single crystals[5].However,the above methods are not applicable to components with complicated shapes due to the inevitable deformation ***,Omori et *** a simply method of abnor-mal grain growth to fabricate ultra-large grains,even single crys-tals,in Cu-Al-Mn[1],Fe-Mn-Al-Ni[2],and Fe-Mn-Al-Ni-Cr[6]*** method involves applying cyclic heat treatment between a high temperature BCC single-phase region and a low tempera-ture BCC+FCC two-phase region[1,2,6-12].Note that the cyclic heat treatment resulted in the formation of BCC sub-grain struc-tures responsible for abnormal grain growth[1,2,6-12].In addition,Yang et *** that abnormal grain growth occurred at above 900℃,and large-grains,even single crystals,were obtained only through annealing cast Cu-based polycrystalline alloys contained coherent nano-particles[13,14].Notably,the cyclic heat treatment and annealing cast alloys are deform

关键词： grain alloys deformation

Mechanism of a dual-phase Ti-Nb alloy exhibiting near-linear elastic deformation

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Rare Metals 2024年第5期43卷 2282-2289页

作者： Yan Guo Wang Ding wen Ma Shun Guo Hao-Dong Meng Nian-Yao xu School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Youke Publishing Co. LtdChina Grinm Group Co.LtdBeijing 100088China

In this work,the underlying mechanism responsible for the near-linear elastic deformation behavior of a dual-phase Ti-Nb alloy consisting of β and α'' phase with large recoverable strain was systematically *** on in situ synchrotron X-ray diffraction(SXRD)analyses,it was found that besides intrinsic elastic deformation,a slight reversible β-α'' stress-induced martensitic(SIM)transformation,which proceeded in a consecutive mode under the retarding effect of micro-defects,took place during the near-linear elastic *** unloading,a small amount of residual macroscopic strain remained in the specimen due to the incomplete reverse α''→β transformation on *** high near-linear elastic deformability of the cold drawing(CD)Ti-Nb alloy has been revealed to be attributed to the coupling actions of intrinsic elasticity as well as the consecutive and reversible β-α'' SIM *** research may contribute to a new avenue for the design and development of novel dual-phase Ti-based alloys with desirable elastic deformability.

关键词： Titanium alloys Dual-phase Near-linear elastic deformation Martensitictransformation

Notch1 signaling regulate astrocyte proliferation after Lipopolysaccharide stimulated

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Notch1 signaling regulate astrocyte proliferation after Lipo...

Notch1 signaling regulate astrocyte proliferation after Lipopolysaccharide stimulated

2018年浙江省医学会妇产科学与围产医学学术年会暨2018年浙江省医师协会妇产科医师分会学术年会

作者： Shu-Xin Dai wen-fang xu Li-fang Lin Hua-Zi Liu Tian-Ming Yuan Department of Neonatology Children’s HospitalZhejiang University School of Medicine

Background:Astrocyte proliferation is the main feature of astrogliosis,which is the response of astrocytes to *** there is a lot of evidence that infection is associated with *** we want to explore the relationship between infection and Astrocyte proliferation and the mechanisms behind ***:Primary rat astrocytes were treated with lipopolysaccharide(LPS) compared to the control *** siRNA technology to over-expression or inhibit expression of Notchl in *** of cell number,glial fibrillary acidic protein(GFAP) expression,and methylation of GFAP ***:LPS promote astrocyte proliferation and Notch-1 *** LPS stimulates astrocytes,overexpression Notchl enhanced astrocyte proliferation and reduced methylation of CpG islands in GFAP gene promoters;Interference expression Notchl inhibited astrocyte proliferation and elevated methylation of CpG islands in GFAP gene ***:Our study demonstrated that LPS promote astrocyte proliferation through Notchl signal.

关键词： lipopolysaccharide astrocyte Notch1 white matter damage

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Notch1 signaling regulate astrocyte proliferation after Lipo...