检索结果-南通市图书馆

Observation of gapless corner modes of photonic crystal slabs in synthetic translation dimensions

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第3期12卷 444-455页

作者： wen-JIN ZHANG hao-CHANG MO wen-JIE chen XIAO-DONG chen JIAN-wen DONG School of Physics&State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou 510275China

Second-order topological photonic crystals support localized corner modes that deviate from the conventional bulk-edge correspondence.However,the frequency shift of corner modes spanning the photonic band gap has not been experimentally reported.Here,we observe the gapless corner modes of photonic crystal slabs within a parameter space by considering translation as an additional synthetic dimension.These corner modes,protected by topological pumping in synthetic translation dimensions,are found to exist independently of the specific corner configuration.The gapless corner modes are experimentally imaged via the near-field scanning measurement and validated numerically by full-wave simulations.We propose a topological rainbow with gradient translation,demonstrating the ability to extract and separate specific frequency components of light into different spatial locations.Our work contributes to the advancement of topological photonics and provides valuable insights into the exploration of gapless corner modes in synthetic dimensions.

关键词： translation dimensions corner

Review of attitude consensus of multiple spacecraft

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2022年第4期6卷 329-356页

作者： Ti chen Jinjun Shan hao wen Shidong Xu State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China Department of Earth and Space Science and Engineering York UniversityToronto M3J 1P3Canada

A group of cooperative agents can finish complicated missions that are difficult for a large machine.In the past two decades,spacecraft attitude coordination has attracted significant research attention owing to its wide potential applications.This paper presents a survey of recent research progress on the spacecraft attitude consensus problem,paying particular attention to the papers published in major aerospace,dynamics,automation,and robotics journals since 2015.Attitude consensus concepts for centralized,decentralized,and distributed cases are reviewed.This overview summarizes results on system dynamics and consensus algorithms based on frequently used attitude representations,such as Euler angles,modified Rodrigues parameters,unit quaternions,and rotation matrices.Studies conducted under complicated operating conditions are also covered.Experimental results on attitude consensus are discussed.In the final section,the main conclusions are drawn and several potential research directions are provided.

关键词： attitude consensus networked spacecraft communication graph multi-agent systems(MAS) attitude synchronization

Experimental Investigation on the Vibration Attenuation of Tensegrity Prisms Integrated with Particle Dampers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2022年第4期35卷 672-681页

作者： Si-Qi An hao-Ran Zou wen-hao Li Zi-chen Deng School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China

Tensegrities made of tensile strings and compressed struts possess large strength-to-mass ratio values but tend to experience non-negligible vibration in dynamic environments because of poor structural damping.Here,we introduce particle dampers into a tensegrity prism to attenuate vibration,with the goal of establishing a lightweight and efficient approach of vibration suppression.To integrate the particle dampers and the tensegrity,a novel strut structure formed by assembling a solid strut and a hollow strut is devised,in which granular materials are inserted to develop a particle damper.The vibration attenuation performance of the tensegrity prism is investigated through exciter tests.According to the experimental parametric study,the influences of system parameters including excitation magnitude,the filling height of particles,particle size and the configuration of tensegrity prism on the vibration attenuation performance is analyzed.In addition,the experimental results regarding the dependence of the vibration attenuation on the system parameters are interpreted by the mechanism of collisions and frictions between particles and between particles and struts.The maximal vibration attenuation ratio of 76%can be achieved in the experiments.Thus,this research can provide insights into the design of lightweight tensegrity structures where vibration suppression is important,particularly in some dynamic environments.

关键词： Tensegrity structures Particle dampers Vibration suppression Assembling struts

Microdeletions and vertical transmission of the Y-chromosome azoospermia factor region

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2023年第1期25卷 5-12页

作者： chen-Yao Deng Zhe Zhang wen-hao Tang Hui Jiang Department of Urology Third Hospital of Peking UniversityBeijing 100089China Department of Andrology Third Hospital of Peking UniversityBeijing 100089China Department of Human Sperm Bank Third Hospital of Peking UniversityBeijing 100089China

Spermatogenesis is regulated by several Y chromosome-specific genes located in a specific region of the long arm of the Y chromosome,the azoospermia factor region(AZF).AZF microdeletions are the main structural chromosomal abnormalities that cause male infertility.Assisted reproductive technology(ART)has been used to overcome natural fertilization barriers,allowing infertile couples to have children.However,these techniques increase the risk of vertical transmission of genetic defects.Despite widespread awareness of AZF microdeletions,the occurrence of de novo deletions and overexpression,as well as the expansion of AZF microdeletion vertical transmission,remains unknown.This review summarizes the mechanism of AZF microdeletion and the function of the candidate genes in the AZF region and their corresponding clinical phenotypes.Moreover,vertical transmission cases of AZF microdeletions,the impact of vertical inheritance on male fertility,and the prospective direction of research in this field are also outlined.

关键词： azoospermia factor male infertility microdeletion vertical transmission

A chitosan-based antibacterial hydrogel with injectable and self-healing capabilities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第1期6卷 115-125页

作者： Rui chen Yanan hao Secundo Francesco Xiangzhao Mao wen-Can Huang State Key Laboratory of Marine Food Processing and Safety Control College of Food Science and EngineeringOcean University of ChinaQingdao 266404China Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Qingdao 266237China Qingdao Key Laboratory of Food Biotechnology Qingdao 266404China Key Laboratory of Biological Processing of Aquatic Products China National Light IndustryQingdao 266404China Istituto di Scienze e Tecnologie Chimiche“Giulio Natta” Consiglio Nazionale delle Ricerche via Mario Bianco 920131 MilanItaly

The presence of bacteria directly affects wound healing.Chitosan-based hydrogel biomaterials are a solution as they offer advantages for wound-healing applications due to their strong antimicrobial properties.Here,a double-cross-linking chitosanbased hydrogel with antibacterial,self-healing,and injectable properties is reported.Thiolated chitosan was successfully prepared,and the thiolated chitosan molecules were cross-linked by Ag-S coordination to form a supramolecular hydrogel.Subsequently,the amine groups in the thiolated chitosan covalently cross-linked with genipin to further promote hydrogel formation.In vitro experimental results indicate that hydrogel can release Ag^(+)over an extended time,achieving an antibacterial rate of over 99% against Escherichia coli and Staphylococcus aureus.Due to the reversible and dynamic feature of Ag-S coordination,an antibacterial hydrogel exhibited injectable and self-healing capabilities.Additionally,the hydrogel showed excellent biocompatibility and biodegradability.

关键词： Hydrogel Chitosan Silver ion Cross-linking Antibacterial

Prominent juxtacortical white matter lesion hallmarks NOTCH3-related intracerebral haemorrhage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2022年第1期7卷 38-46页

作者： Chih-hao chen hao-Chia Hsu Yu-wen cheng Ya-Fang chen Sung-Chun Tang Jiann-Shing Jeng Neurology National Taiwan University HospitalTaipeiTaiwan Department of Neurology National Taiwan University HospitalTaipeiTaiwan Department of Neurology National Taiwan University Hospital Hsinchu BranchHsinchuTaiwan Medical Imaging National Taiwan University HospitalTaipeiTaiwan

Background and purpose NOTCH3 p.R544C mutation accounts for 5%of spontaneous intracerebral haemorrhage(ICH)in East Asian patients.We investigated whether certain CT features are associated with NOTCH3-related ICH.Methods Patients with spontaneous ICH from a prospective stroke registry were screened for NOTCH3 p.R544C mutation.The neuroimaging features on the initial non-contrast CT scans selected to predict NOTCH3 p.R544C mutation,including burden of white matter lesion(WML),degree of brain atrophy,number of lacunes,prominent juxtacortical WML and prominent lobar lacunes,were analysed by neuroradiologists blinded to the mutation status.Results Of 299 patients with spontaneous ICH(mean age,61 years;male,68%;ICH volumes,14.1±17.8 mL),13 patients(4.3%)carried NOTCH3 p.R544C mutation.The clinical features,haematoma size and location were similar between NOTCH3 p.R544C mutation carriers and non-carriers.The CT scan revealed that patients with NOTCH3 p.R544C mutation had more severe WML and more frequently had prominent juxtacortical WML(69.2%vs 17.8%,p<0.001),and the effects were not driven by ageing as seen in patients without mutation.Prominent juxtacortical WML(area under receiver operating characteristic curve=0.76)outperformed the total WML score and prominent lobar lacunes and significantly predicted NOTCH3 p.R544C mutation in a multivariable-adjusted model(OR,20.9;95%CI 4.94 to 88.6).Conclusion In patients with spontaneous ICH,the severity and topographic distribution of WML can help in identifying potential NOTCH3 mutation-related ICH.

关键词： NOTCH3 intracerebral white

Transmission Line Insulator Defect Detection Based on Swin Transformer and Context

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine Intelligence Research 2023年第5期20卷 729-740页

作者： Yu Xi Ke Zhou Ling-wen Meng Bo chen hao-Min chen Jing-Yi Zhang Digital Grid Research Institute China Southern Power GridGuangzhou 510000China Institute of Electric Power Research of Guangxi Power Grid Nanning 530023China Institute of Electric Power Research of Guizhou Power Grid Guiyang 550000China School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China

Insulators are important components of power transmission lines.Once a failure occurs,it may cause a large-scale blackout and other hidden dangers.Due to the large image size and complex background,detecting small defect objects is a challenge.We make improvements based on the two-stage network Faster R-convolutional neural networks(CNN).First,we use a hierarchical Swin Transformer with shifted windows as the feature extraction network,instead of ResNet,to extract more discriminative features,and then design the deformable receptive field block to encode global and local context information,which is utilized to capture key clues for detecting objects in complex backgrounds.Finally,the filling data augmentation method is proposed for the problem of insufficient defects and more images of insulator defects under different backgrounds are added to the training set to improve the robustness of the model.As a result,the recall increases from 89.5%to 92.1%,and the average precision increases from 81.0%to 87.1%.To further prove the superiority of the proposed algorithm,we also tested the model on the public data set Pascal visual object classes(VOC),which also yields outstanding results.

关键词： Insulator defect object detection Swin transformer data augmentation context information

Tilianin extracted from Xiangqinglan(Herba Dracocephali Moldovicae)inhibits apoptosis induced by mitochondrial pathway and endoplasmic reticulum stress in H9c2 cells after oxygen-glucose deprivation/reoxygenation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2023年第1期43卷 42-50页

作者： JIANG wen ZHANG Wei ZHANG Yuxiang YANG hao PAN Xiaomei chen Qiang chen Junhui Department of Pharmacy the Sixth Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830000China Department of Anesthesiology the First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830000China Department of Laboratory the Sixth Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830000China

OBJECTIVE:To investigate the efficacy of tilianin extracted from Xiangqinglan(Herba Dracocephali Moldovicae)on apoptosis of H9c2 cell after oxygenglucose deprivation/reoxygenation(OGD/R)and the mechanism.METHODS:Tilianin was obtained from Beijing Inluck Science and Technology Development Co.Ltd.,with purity≥98%.The OGD/R model was established in H9c2 cells.Flow cytometry detected the mitochondrial membrane potential,apoptosis rates,mitochondrial reactive oxygen species(ROS)and calcium ion concentration.Succinate dehydrogenase(SDH)activity,succinate content and levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β)were detected with enzyme-linked immunosorbent assay.Western blot measured protein levels.RESULTS:Tilianin significantly reduced the apoptotic rates,ROS levels,calcium ion concentration,succinate content,and,levels of TNF-α,IL-6 and IL-1βof OGD/R cells,while significantly increased the membrane potential and SDH activity in mitochondria.Western blot analysis showed that tilianin significantly up-regulated pCalmodulin-dependent protein kinaseⅡand voltagedependent anion selective channel levels in OGD/R cells,while significantly down-regulated p-protein kinase B,Bcl-2-associated X,and dynamin-related protein 1 levels related to apoptosis in the mitochondrial pathway.Moreover,tilianin significantly up-regulated B-cell lymphoma-2 and mitochondrial protein 2 related to the inhibition of apoptosis.Furthermore,tilianin downregulated phosphorylated-apoptosis signal-regulated kinase 1,phosphorylated-p38 and C/EBP homologous protein related to endoplasmic reticulum stress.CONCLUSIONS:Tilianin may inhibit OGD/R-induced H9c2 cell apoptosis mediated by mitochondrial pathway and endoplasmic reticulum stress,thus protecting cardiomyocytes.

关键词： apoptosis mitochondria endoplasmic reticulum stress tilianin oxygen-glucose deprivation/reoxygenation

Rheological and mechanical properties of aluminosilicious cementitious materials as refractory castable binders

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2022年第7期29卷 1145-1151页

作者： Zhong-feng Xia Chang-hao chen wen-hao Chi Zhou-fu Wang hao Liu Yan Ma Xi-tang Wang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Metakaolin(MK)is an important refractory raw material,which has been used as a cementitious material.In order to improve the bonding strength of MK,the composite cementitious materials were prepared by MK mixed with hydrat-able alumina(HA)and microsilica(MS),respectively.The silane coupling agent(SCA)was introduced as a modifying agent.The rheological properties of MK-based composite cementitious slurries were investigated.The mechanical properties of corundum castables bonded with the composite cementitious materials and calcium aluminate cement(CAC)were comparatively studied.The results show that SCA improves the rheological properties of MK-based composite cementitious materials.The slurry of MK–MS mixture flows in a plastic manner,while the slurry of MK–HA mixture presents pseudoplastic flow.The addition of SCA reduces the yield stress value of the MK–HA slurry.The bonding strength of castables bonded with MK-based composite cementitious materials is lower than that of CAC bonding castables.The room temperature strength of MK–MS composite bonding castable remains the highest after being treated either at 1100 or 1550°C,and its high temperature modulus of rupture is higher than that of CAC bonding castables with microsilica added.

关键词： Metakaolin Hydratable alumina Microsilica Silane coupling agent Corundum castable Calcium aluminate cement