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Sandwich structures with tapered tubes as core:A quasi-static investigation

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Defence Technology（防务技术） 2024年第3期33卷 447-462页

作者： Xinmei xiang Dehua Shao Xin Zhang Umer Sharif ngoc San Ha Li xiang Jing Zhang Jiang Yi School of Civil Engineering Guangzhou UniversityGuangzhouChina Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhenGuangdongChina School of Engineering Centre for Innovative Structures and MaterialsRMIT UniversityMelbourneAustralia China Southern Airlines Co. LtdShenzhen BranchShenzhen518000China

In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without *** results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube ***,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their ***,the tapered corrugated tubes'resistance to oblique impacts was *** to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical *** conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall *** and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10.

关键词： Sandwich structure Corrugated tube Tapered tube Quasi-static Energy absorption

Adversarial data splitting for domain generalization

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Science China(Information Sciences) 2024年第5期67卷 28-42页

作者： xiang GU Jian SUN Zongben XU School of Mathematics and Statistics Xi'an Jiaotong University

Domain generalization aims to learn a model that is generalizable to an unseen target domain,which is a fundamental and challenging task in machine learning for out-of-distribution generalization. This paper proposes a novel domain generalization approach that enforces the learned model to be able to generalize well over the train/val subset splitting of the training dataset. This idea is modeled herein as an adversarial data splitting framework, formulated as a min-max optimization problem inspired by the metalearning approach. The min-max optimization problem is solved by iteratively splitting the training dataset into the training and val subsets to maximize the domain shift measured by the objective function and updating the model parameters to enable the model to generalize well from the training subset to the val subset by minimizing the objective function. This adversarial training approach does not assume the known domain labels of the training data; instead, it automatically investigates the “hard” splitting of the train/val subsets to learn the generalizable model. Extensive experimental results using three benchmark datasets demonstrate the superiority of this approach. In addition, we derive a generalization error bound for the theoretical understanding of our proposed approach.

关键词： domain generalization adversarial learning data splitting meta-learning out of distribution

Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression

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Neural Regeneration Research 2024年第10期19卷 2144-2156页

作者： Ying Ma Yue Qiao xiang Gao Spinal Cord and Brain Injury Research Group Stark Neuroscience Research InstituteIndianapolisINUSA Department of Neurological Surgery Indiana University School of MedicineIndianapolisINUSA Department of Neurology Shengjing Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The largescale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression.

关键词： antidepressants chronic pain depression exercise hippocampal neurogenesis inflammation inhibition neuroinflammation physical activity deficits social isolation spinal cord injury

Lifetime-tunable circularly polarized luminescent system based on triplet-to-singlet Förster resonance energy transfer

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Science China Chemistry 2024年第9期67卷 2918-2922页

作者： Zhenyi He Zizhao Huang xiang Ma Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Institute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Circularly polarized luminescence(CPL)materials have received widespread attention due to their remarkable performance and broad ***,current CPL material research primarily focuses on tunable color,intensity,and *** CPL with adjustable lifetime remains a significant ***,a series of CPL polymeric materials with tunable lifetime were obtained by employing phosphorescent terephthalic acid and chiral organic small molecule R/S-BNAF(a luminescent binaphthol derivative)to copolymerize with acrylamide in different *** was verified that this performance results from the different energy transfer efficiency between luminophores with varying ratios of the monomers for *** strategy to realize CPL with tunable lifetime by modulating the energy transfer efficiency will provide a new perspective to broaden the applications of CPL materials.

关键词： circularly polarized luminescence tunable lifetime Förster resonance energy transfer room temperature phosphorescence

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang Wu Jia Qu Lin-zhi Wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Quantized bound states around a vortex in anisotropic superconductors

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 146-155页

作者： Ke xiang Da Wang Qiang-Hua Wang National Laboratory of Solid State Microstructures&School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

The bound states around a vortex in anisotropic superconductors is a longstanding yet important *** this work,we develop a variational theory on the basis of the Andreev approximation to obtain the energy levels and wave functions of the low-energy quantized bound states in superconductors with anisotropic pairing on arbitrary Fermi *** the case of circular Fermi surface,the effective Schr¨odinger equation yielding the bound state energies gets back to the theory proposed by Volovik and Kopnin many years *** generalization here enables us to prove the equidistant energy spectrum inside a vortex in a broader class of *** importantly,we are now able to obtain the wave functions of these bound states by projecting the quasiclassical wave function on the eigenmodes of the effective Schr¨odinger equation,going beyond the quasiclassical Eilenberger results,which,as we find,are sensitive to the scattering *** the case of isotropic Fermi surface,the spatial profile of the low-energy local density of states is dominated near the vortex center and elongates along the gap antinode directions,in addition to the ubiquitous Friedel oscillation arising from the quantum inteference neglected in the Eilenberger ***,as a consequence of the pairing anisotropy,the quantized wave functions develop a peculiar distribution of winding number,which reduces stepwise towards the vortex *** work provides a flexible way to study the vortex bound states in the future.

关键词： vortex bound state anisotropic superconductor Andreev approximation

Removal of Cr(Ⅵ)by glutaraldehyde-crosslinked chitosan encapsulating microscale zero-valent iron:Synthesis,mechanism,and longevity

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Journal of Environmental Sciences 2024年第8期142卷 115-128页

作者： Yijun Duan Fang Liu xiang Liu Miao Li School of Environment Tsinghua UniversityBeijing 100084China Transportation Institute of Inner Mongolia University Hohhot 010070China

Microscale zero-valent iron(mZVI)has shown great potential for groundwater Cr(Ⅵ)***,low Cr(Ⅵ)removal capacity caused by passivation restricted the wide use of *** prepared mZVI/GCS by encapsulating mZVI in a porous glutaraldehydecrosslinked chitosan matrix,and the formation of the passivation layer was alleviated by reducing the contact between zero-valent iron *** average pore diameter of mZVI/GCS was 8.775 nm,which confirmed the mesoporous characteristic of this *** of batch experiments demonstrated that mZVI/GCS exhibited high Cr(Ⅵ)removal efficiency in a wide range of pH(2-10)and temperature(5-35℃).Common groundwater coexisting ions slightly affected m ZVI/*** material showed great reusability,and the average Cr(Ⅵ)removal efficiency was 90.41%during eight *** this study,we also conducted kinetics and isotherms ***-second-order model was the most matched kinetics *** Cr(Ⅵ)adsorption process was fitted by both Langmuir and Freundlich isotherms models,and the maximum Langmuir adsorption capacity of m ZVI/GCS reached243.63 mg/g,which is higher than the adsorption capacities of materials reported in most of the previous ***,the column capacity for Cr(Ⅵ)removal of a mZVI/GCS-packed column was 6.4 times higher than that of a mZVI-packed column in a 50-day ***,mZVI/GCS with a porous structure effectively relieved passivation problems of mZVI and showed practical application prospects as groundwater Cr(Ⅵ)remediation material with practical application prospects.

关键词： Chitosan Glutaraldehyde mZVI Cr(Ⅵ) Groundwater

Biomimetic Gland Models with Engineered Stratagems

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Research 2024年第2期2023卷 583-612页

作者： xiang Lin Lingyu Sun Minhui Lu Yuanjin Zhao Department of Rheumatology and Immunology Nanjng Drum Tower HospitalSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhouZhejiang 325001China Southeast University Shenzhen Research Institute Shenzhen 518071China

As extensively distributed tissues throughout the human body,glands play a critical role in various physiological ***,the construction of biomimetic gland models in vitro has aroused great interest in multiple *** the biological field,the researchers focus on optimizing the cell sources and culture techniques to reconstruct the specific structures and functions of glands,such as the emergence of organoid *** the perspective of biomedical engineering,the generation of biomimetic gland models depends on the combination of engineered scaffolds and microfluidics,to mimic the in vivo environment of glandular *** engineered stratagems endowed gland models with more biomimetic features,as well as a wide range of application *** this review,we first describe the biomimetic strategies for constructing different in vitro gland models,focusing on the role of microfluidics in promoting the structure and function development of biomimetic *** summarizing several common in vitro models of endocrine and exocrine glands,the applications of gland models in disease modelling,drug screening,regenerative medicine,and personalized medicine are ***,we conclude the current challenges and our perspective of these biomimetic gland models.

关键词： endowed constructing strata

E-MobileNeXt: face expression recognition model based on improved MobileNeXt

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Optoelectronics Letters 2024年第2期20卷 122-128页

作者： ZHAng xiang YAN Chunman School of Physics and Electronic Engineering Northwest Normal UniversityLanzhou 730070China1

In response to the high complexity and low accuracy of current facial expression recognition networks, this paper proposes an E-Mobile Ne Xt network for facial expression recognition. E-Mobile Ne Xt is built based on our proposed E-Sand Glass block. In addition, we also improve the overall performance of the network through Rep Conv and SGE attention mechanisms. The experimental results show that the network model improves the expression recognition accuracy by 6.5% and 7.15% in RAF-DB and CK+ datasets, respectively, while the parameter and floating-point operations decreased by 0.79 M and 4.2 M compared with Mobile Ne Xt.

关键词： facial mechanisms. network