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A Hybrid Level Set Optimization Design Method of Functionally Graded Cellular Structures Considering Connectivity

Computers, Materials & Continua 2024年第4期79卷 1-18页

作者： Yan Dong kang Zhao Liang Gao Hao Li The State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China Institute of Systems Engineering China Academy of Engineering PhysicsMianyang621900China

With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown ***,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular *** HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure ***,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both ***,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent *** method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology *** essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures.

关键词： Hybrid level set method functionally graded cellular structure connectivity interpolated transition optimization design

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Biotic and abiotic stresses on honeybee health

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Integrative Zoology 2024年第3期19卷 442-457页

作者： Zheguang LIN Siyi SHEN kang WANG Ting JI Apicultural Research Institute College of Animal Science and TechnologyYangzhou UniversityYangzhouChina

Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable *** a backdrop of rapid global change,this eusocial insect encounters a succession of stressors during nesting,foraging,and *** mites,together with vectored viruses,have been recognized as central biotic threats to honeybee health,while the spread of invasive giant hornets and small hive beetles also increasingly threatens colonies *** of agrochemicals,including acaricides used for mite treatment,and other pollutants of the environment have been widely documented to affect bee health in various ***,expanding urbanization,climate change,and agricultural intensification often result in the destruction or fragmentation of flower-rich bee *** anthropogenic pressures exerted by beekeeping management practices affect the natural selection and evolution of honeybees,and colony translocations facilitate alien species invasion and disease *** this review,the multiple biotic and abiotic threats and their interactions that potentially undermine bee colony health are discussed,while taking into consideration the sensitivity,large foraging area,dense network among related nestmates,and social behaviors of honeybees.

关键词： abiotic stressor Apis biotic stressor colony losses interaction effect pollinator decline

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Postnatal development of rat retina:a continuous observation and comparison between the organotypic retinal explant model and in vivo development

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Neural Regeneration Research 2025年第3期20卷 900-912页

作者： Baoqi Hu rui Wang Hanyue Zhang Xiou Wang Sijia Zhou Bo Ma Yan Luan Xin Wang Xinlin Chen Zhichao Zhang Qianyan kang Department of Ophthalmology The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi ProvinceChina Department of Ophthalmology The First Affiliated Hospital of Northwest UniversityXi’anShaanxi ProvinceChina Institute of Neurobiology Xi’an Jiaotong University Health Science CenterXi’anShaanxi ProvinceChina

The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell ***,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development ***,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo *** this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in ***,we used SOX2 and PAX6 immunostaining to identify retinal progenitor *** then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,***-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between ***,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,*** timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant *** study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina *** findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.

关键词： bipolar cells differentiation in vivo microglia Müller glia organotypic retinal explant culture postnatal retina development proliferation retinal progenitor cells

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Deep Global Multiple-Scale and Local Patches Attention Dual-Branch Network for Pose-Invariant Facial Expression Recognition

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 405-440页

作者： Chaoji Liu Xingqiao Liu Chong Chen kang Zhou School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013China School of Electrical Engineering Yancheng Institute of TechnologyYancheng224051China

Pose-invariant facial expression recognition(FER)is an active but challenging research topic in computer *** with the involvement of diverse observation angles,FER makes the training parameter models inconsistent from one view to *** study develops a deep global multiple-scale and local patches attention(GMS-LPA)dual-branch network for pose-invariant FER to weaken the influence of pose variation and selfocclusion on recognition *** this research,the designed GMS-LPA network contains four main parts,i.e.,the feature extraction module,the global multiple-scale(GMS)module,the local patches attention(LPA)module,and the model-level fusion *** feature extraction module is designed to extract and normalize texture information to the same *** GMS model can extract deep global features with different receptive fields,releasing the sensitivity of deeper convolution layers to pose-variant and *** LPA module is built to force the network to focus on local salient features,which can lower the effect of pose variation and self-occlusion on recognition ***,the extracted features are fused with a model-level strategy to improve recognition *** experimentswere conducted on four public databases,and the recognition results demonstrated the feasibility and validity of the proposed methods.

关键词： Pose-invariant FER global multiple-scale(GMS) local patches attention(LPA) model-level fusion

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Physics-informed deep Koopman operator for Lagrangian dynamic systems

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Science China(Information Sciences) 2024年第9期67卷 146-163页

作者： xuefeng WANG Yang CAO Shaofeng CHEN Yu kang Department of Automation University of Science and Technology of China State Key Laboratory of Fire Science University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China

Accurate mechanical system models are crucial for safe and stable control. Unlike linear systems,Lagrangian systems are highly nonlinear and difficult to optimize because of their unknown system *** research thus used deep neural networks to generate linear models of original systems by mapping nonlinear dynamic systems into a linear space with a Koopman observable function encoder. The controller then relies on the Koopman linear model. However, without physical information constraints, ensuring control consistency between the original nonlinear system and the Koopman system is tough, as the learning process of the Koopman observation function is unsupervised. This paper thus proposes a two-stage learning algorithm that uses structural subnetworks to build a physics-informed network topology to simultaneously learn the Koopman observable functions and the system energy representation. In the Koopman matrix learning session, a quadratic-constrained optimization problem is solved to ensure that the Koopman representation satisfies the energy difference matching hard constraint. The proposed energy-preserving deep Lagrangian Koopman(EPDLK) framework effectively represents the dynamics of the Lagrangian system while ensuring control consistency. The effectiveness of EPDLK is compared with those of various Koopman observable function construction methods in multistep prediction and trajectory tracking tasks. EPDLK achieves better control consistency by guaranteeing energy difference matching, which facilitates the application of the control law generated on the Koopman system directly to the original nonlinear Lagrangian system.

关键词： Koopman operator Lagrangian physics-informed nonlinear model predictive control (MPC)

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Experimental investigation on fluid-induced slip behavior of fault filled with fault gouge

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3661-3672页

作者： Yongshui kang Zhi Geng Bin Liu Youqi Huang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Fault zones are usually filled with fault gouge and accompanied by fault *** coupled effect of fault gouge and water significantly impacts the slip behavior of the fault,which may weaken the fault structure and further induce rupture propagation and *** this study,we carried out a laboratory experiment to investigate the fluid-induced slip behavior of fault filled with *** friction evolution characteristic associated with fluid pressure and effective stress was investigated during the slip *** addition,the role transformation process of the gouge on the slip behavior of fault was *** experimental result indicates that the friction on the filled fault surface is significantly affected by fault *** rupture of the gouge promotes fault slip and the fluid pressure plays a vital role in the initiation of fault *** fault gouge enhances the shearing strength of the fault and acts as a barrier before the initial slip under fluid ***,the fault gouge would accelerate the fault slip and transform into lubricant after the initial slip.

关键词： Fault gouge Fluid Slip behavior Friction Shear strength

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Cadherin-18 loss in prospermatogonia and spermatogonial stem cells enhances cell adhesion through a compensatory mechanism

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Zoological Research 2024年第5期45卷 1048-1060页

作者： Xiao-Xiao Li Dan-Chen Zhang Yan Wang Jian Wen Xing-Ju Wang Yu-Lu Cao Ru Jiang Jia-rui Li Yi-Nuo Li He-He Liu Wen-Hai Xie Zheng-Feng Xu Ping Hu kang Zou Germline Stem Cells and Microenvironment Lab College of Animal Science and TechnologyNanjing Agricultural UniversityNanjingJiangsu 210095China Stem Cell Research and Translation Center Nanjing Agricultural UniversityNanjingJiangsu 210095China School of Life Sciences and Medicine Shandong University of TechnologyZiboShandong 255000China Department of Prenatal Diagnosis Women’s Hospital of Nanjing Medical UniversityNanjing Maternity and Child Health Care HospitalNanjingJiangsu 210004China

Extracellular membrane proteins are crucial for mediating cell attachment,recognition,and signal transduction in the testicular microenvironment,particularly germline stem *** 18(CDH18),a type II classical cadherin,is primarily expressed in the nervous and reproductive ***,we investigated the expression of CDH18 in neonatal porcine prospermatogonia(ProSGs)and murine spermatogonial stem cells(SSCs).Disruption of CDH18 expression did not adversely affect cell morphology,proliferation,self-renewal,or differentiation in cultured porcine ProSGs,but enhanced cell adhesion and prolonged cell *** analysis indicated that the down-regulation of CDH18 in ProSGs significantly up-regulated genes and signaling pathways associated with cell *** further elucidate the function of CDH18 in germ cells,Cdh18 knockout mice were generated,which exhibited normal testicular morphology,histology,and *** analysis showed increased expression of genes associated with adhesion,consistent with the observations in porcine *** interaction of CDH18 withβ-catenin and JAK2 in both porcine ProSGs and murine SSCs suggested an inhibitory effect on the canonical Wnt and JAK-STAT signaling pathways during CDH18 ***,these findings highlight the crucial role of CDH18 in regulating cell adhesion in porcine ProSGs and mouse *** this regulatory mechanism provides significant insights into the testicular niche.

关键词： Extracellular signal Fertility Quiescency Wnt signaling pathway

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Heterobimetallic[NiCo]integration in a hydrogenase mimic for boosting light-driven hydrogen evolution in CaTiO_(3)

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Nano Research 2024年第8期17卷 6888-6894页

作者： kang Li Juanji Hong Ningning Song Zhanjun Guo Minmin Liang Experimental Center of Advanced Materials School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 10081China

Light-drive hydrogen production using titanium-based perovskite is one sustainable way to reduce current reliance on fossil fuels,but its wide applications are still limited by high electron−hole recombination and sluggish surface ***,the developments for low-cost and highly efficient co-catalysts remain *** by natural[NiFe]-hydrogenase active center structure,a hydrogenase-mimic,NiCo_(2)S_(4) nanozyme was synthesized,and subsequently decorated onto the CaTiO_(3) to catalyze the hydrogen evolution reaction(HER).Among the following test,CaTiO_(3)with a 15%loading of NiCo_(2)S_(4) nanozyme exhibited the highest HER rate of 307.76μmol·g^(–1)·h^(–1),which is 60 times higher than that of the CaTiO_(3) *** results reveal that NiCo_(2)S_(4) not only significantly increased the charge separation efficiency of the photogenerated carriers,but also substantively lowered the HER activation *** studies show that NiCo_(2)S_(4) readily splits H_(2)O by forming the Ni(OH)-Co intermediate and only Ni in the bimetallic center alters the oxidation state during the HER process in a manner analogous to the[NiFe]-*** contrast to the often-expensive synthetic catalysts that rely on rare elements such as ruthenium and platinum,this study shows a promising way to develop the nature-inspired cocatalysts to enhance the photocatalysts’HER performance.

关键词： hydrogen evolution reaction hydrogenase-mimic nanozyme photocatalyst water-splitting

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Autonomous multi-drone racing method based on deep reinforcement learning

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu kang Jian DI Ming LI Yunbo ZHAO Yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： racing drone autonomous multi-drone racing sim-to-real deep reinforcement learning Markov game

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Light-triggered fluorochromic cholesteric liquid crystal elastomer with hydrogen-bonded fluorescent switch: dualmodal-switchable circularly polarized luminescence

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Science China Chemistry 2024年第8期67卷 2719-2727页

作者： Siyang Lin Tianqi Ren Xianyu Meng Wenxin kang Jinbao Guo Key Laboratory of Carbon Fibers and Functional Polymers Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Solid materials with dynamically tunable circularly polarized luminescence(CPL) feature higher security levels and devicefriendly characteristics, showing great superiority in the field of information technology and anti-counterfeiting. To address the limited photoisomerization of fluorescent photoswitch in CPL-active solid materials, here a cholesteric liquid crystal elastomer(CLCE) containing a hydrogen-bonded(H-bonded) polymerizable fluorescent switch AHBA-PSD is prepared. Owing to the good flexibility and low glass-transition temperature of CLCE, AHBA-PSD shows a fast and fully reversible photocyclization/cycloreversion with fluorochromic behavior in CLCE. Further, by controlling the spectral overlapping area between the emission and reflection bands, the CLCE exhibits a strong CPL with a g_(lum) value of up to 0.76 accompanied by a reversible phototunable CPL signal. Meanwhile, the H-bond helps to stabilize the mechanical property, and the force-induced switching-off of CPL signal could be achieved due to the destroyed helical structures by external force. Finally, an automatically-recognized identification card with abundant chiroptical information is demonstrated.

关键词： cholesteric liquid crystal elastomer circularly polarized luminescence fluorescent photoswitch diarylethene photoismerization

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