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Enhanced plasticity of spontaneous coagulation cast oxide ceramic green bodies

Journal of Advanced Ceramics 2024年第5期13卷 568-578页

作者： Juanjuan wang jin Zhao Junyan Mao Wenlong Liu Haohao ji jian Zhang Shiwei wang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

In the preparation of large-sized ceramics,the use of a green body with relatively high plasticity is crucial to minimize the risk of cracking during *** achieve this goal,glycerol and polyethylene glycol(PEG)were utilized as plasticizers in the shaping of green bodies of oxide ceramics through spontaneous coagulation casting(SCC).This study investigated the effects of plasticizers and particle sizes ranging from the submicron to nanoscale on the slurry viscosity,drying shrinkage of wet gels,and mechanical properties of green *** plasticity of the green bodies was assessed by measuring the impact toughness and flexural stress‒strain *** incorporating an appropriate plasticizer,the peak width of the flexural stress‒strain curve for dried green bodies from particles of different sizes was nearly twice that without plasticizers,and the impact toughness was enhanced by approximately 71%,34%,and 41%when the particle size decreased from the submicron scale to the nanoscale(0.45μm,0.18μm,and 50 nm,respectively).The drilling test revealed that there was nearly no cracking around the holes in the green bodies with *** plasticity mechanism of the green bodies was examined based on ultraviolet–visible(UV–Vis)spectroscopy and scanning electron microscopy(SEM).It was discovered that plasticizers might mitigate the brittleness of green bodies by adjusting the interactions between molecules and modifying the gel network properly.

关键词： green body plasticity plasticizer particle size impact toughness stress-strain curve

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Intelligent diagnosis of retinal vein occlusion based on color fundus photographs

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 1-6页

作者： Yu-Ke ji Rong-Rong hua Sha Liu Cui-Juan Xie Shao-Chong Zhang Wei-hua Yang Eye Hospital Nanjing Medical UniversityNanjing 210000Jiangsu ProvinceChina College of Electronic Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210000Jiangsu ProvinceChina Shenzhen Eye Institute Shenzhen Eye HospitalJinan UniversityShenzhen 518000Guangdong ProvinceChina

AIM:To develop an artificial intelligence(AI)diagnosis model based on deep learning(DL)algorithm to diagnose different types of retinal vein occlusion(RVO)by recognizing color fundus photographs(CFPs).METHODS:Totally 914 CFPs of healthy people and patients with RVO were collected as experimental data sets,and used to train,verify and test the diagnostic model of *** the images were divided into four categories[normal,central retinal vein occlusion(CRVO),branch retinal vein occlusion(BRVO),and macular retinal vein occlusion(MRVO)]by three fundus disease *** Transformer was used to build the RVO diagnosis model,and different types of RVO diagnosis experiments were *** model’s performance was compared to that of the ***:The accuracy of the model in the diagnosis of normal,CRVO,BRVO,and MRVO reached 1.000,0.978,0.957,and 0.978;the specificity reached 1.000,0.986,0.982,and 0.976;the sensitivity reached 1.000,0.955,0.917,and 1.000;the F1-Sore reached 1.000,0.9550.943,and 0.887 *** addition,the area under curve of normal,CRVO,BRVO,and MRVO diagnosed by the diagnostic model were 1.000,0.900,0.959 and 0.970,*** diagnostic results were highly consistent with those of fundus disease experts,and the diagnostic performance was ***:The diagnostic model developed in this study can well diagnose different types of RVO,effectively relieve the work pressure of clinicians,and provide help for the follow-up clinical diagnosis and treatment of RVO patients.

关键词： deep learning artificial intelligence Swin Transformer diagnostic model retinal vein occlusion color fundus photographs

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Optical scattering imaging with sub-nanometer precision based on position-ultra-sensitive giant Lamb shift

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 96-105页

作者： Zeyang Liao Yu-Wei Lu Wei Li Xue-hua wang State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

The Lamb shift of a quantum emitter in close proximity to a plasmonic nanostructure can be three or more orders of magnitude larger than that in the free space and is ultra-sensitive to the emitter position and *** demonstrate that this large Lamb shift can be sensitively observed from the scattering or absorption spectrum dip shift of the coupled system when the plasmonic nanoparticle or tip scans the *** these observations,we propose a scanning optical scattering imaging method based on the plasmonic-enhanced Lamb shift with achieves sub-nanometer *** method is based on the scattering or absorption spectrum of the plasmon-emitter coupling system,which is free of the fluorescence quenching problem and easier to implement in a plasmon-emitter coupling *** addition,our scheme works even if the quantum emitter is slightly below the dielectric surface,which can bring about broader applications,such as detecting atoms and molecules or quantum dots above or under a surface.

关键词： Lamb shift plasmon optical scattering imaging

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Different El Niño Flavors and Associated Atmospheric Teleconnections as Simulated in a Hybrid Coupled Model

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Advances in Atmospheric Sciences 2024年第5期41卷 864-880页

作者： Junya HU Hongna wang Chuan GAO Rong-hua ZHANG Key Laboratory of Ocean Circulation and Waves Institute of Oceanologyand Center for Ocean Mega-ScienceChinese Academy of SciencesQingdao 266071China School of Marine Sciences Nanjing University of Information Science and TechnologyNanjing 210044China Laoshan Laboratory Qingdao 266237China

A previously developed hybrid coupled model(HCM)is composed of an intermediate tropical Pacific Ocean model and a global atmospheric general circulation model(AGCM),denoted as *** this study,different El Niño flavors,namely the Eastern-Pacific(EP)and Central-Pacific(CP)types,and the associated global atmospheric teleconnections are examined in a 1000-yr control simulation of the *** HCMAGCM indicates profoundly different characteristics among EP and CP El Niño events in terms of related oceanic and atmospheric variables in the tropical Pacific,including the amplitude and spatial patterns of sea surface temperature(SST),zonal wind stress,and precipitation *** SST budget analysis indicates that the thermocline feedback and zonal advective feedback dominantly contribute to the growth of EP and CP El Niño events,*** to the shifts in the tropical rainfall and deep convection during EP and CP El Niño events,the model also reproduces the differences in the extratropical atmospheric responses during the boreal *** particular,the EP El Niño tends to be dominant in exciting a poleward wave train pattern to the Northern Hemisphere,while the CP El Niño tends to preferably produce a wave train similar to the Pacific North American(PNA)*** a result,different climatic impacts exist in North American regions,with a warm-north and cold-south pattern during an EP El Niño and a warm-northeast and cold-southwest pattern during a CP El Niño,*** modeling result highlights the importance of internal natural processes within the tropical Pacific as they relate to the genesis of ENSO diversity because the active ocean–atmosphere coupling is allowed only in the tropical Pacific within the framework of the HCMAGCM.

关键词： hybrid coupled model tropical Pacific Ocean global atmosphere Eastern/Central-Pacific El Niño atmospheric teleconnections

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A two-pronged strategy utilizing exosomes extracted from antigenpresenting cells to combat hepatitis B

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Nano Research 2024年第10期17卷 9084-9094页

作者： Fumin Hu Dangyang wang Ting Lu Guanghui Ma hua Yue State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Biopharmaceutical Preparation and Delivery Chinese Academy of SciencesBeijing 100190China

Chronic hepatitis B(CHB)is consistently challenging to conquer with numerous complications and *** the effectiveness of antiviral therapies in suppressing hepatitis B virus(HBV)replication,there is an urgent need for novel and more effective treatment *** strategies predominantly emphasize immune activation but still face challenges in sufficiently eliciting T cell *** into account the targeted delivery of nanoparticles to the liver and spleen via intravenous injection,we have proposed a dual-pronged therapeutic strategy based on antigen-presenting cells(APCs)-derived ***,exosomes targeted to the spleen can activate specific immune responses,while those targeted to the liver can modulate or reverse the liver’s immunosuppressive *** immunization,exosome formulations exhibit the remarkable ability to effectively activate APCs,thereby triggering the proliferation of CD8^(+)T ***,they also play an immunoregulatory role by converting M2 macrophages into M1 *** two-pronged therapeutic strategy precisely addresses the issues of T cell dysfunction and immune suppression,both characteristic features of CHB *** combined with Aluminum(Alum)-adjuvanted vaccine,these exosome formulations not only demonstrate a high level of cellular immune response but also secrete specific antibodies comparable to those induced by Alum *** combined approach effectively enhances both cellular and humoral immunity,offering a promising avenue for the development of therapeutic hepatitis B vaccines based on exosome formulations.

关键词： chronic hepatitis B antigen-presenting cells(APCs)-derived exosomes immunoregulatory role two-pronged therapeutic strategy

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Electrochemically recycling degraded superalloy and valorizing CO_(2)in the aff ordable borate-modified molten electrolyte

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Tungsten 2024年第2期6卷 382-393页

作者： Xiang Chen Yuan Sun Long wang Xin Qu Yan Zhao Hong-Wei Xie Di-hua wang hua-Yi Yin Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang 110819China Institute of Metal Research Chinese Academy of ScienceShenyang 110016China School of Resource and Environmental Science Wuhan UniversityWuhan 430072China

Integrating electrochemical reduction of CO_(2)and electrochemical oxidation to recycle degraded superalloys is a promising solution to ease resource scarcity and safeguard environmental ***,we propose an electrochemical technique for the conversion of bulk superalloy scraps and CO_(2)into oxide powder at the anode and solid carbon at the cathode,*** particular,a borax-modifi ed CaCl_(2)-based molten salt electrolyte is used for enhancing the electrochemical oxidation of superalloy *** a temperature of 700℃and a voltage of 2.8 V,90.55 wt.%of alloy scraps were oxidized in a molten CaCl_(2)–NaCl–CaCO_(3)–Na_(2)B_(4)O_(7)with an acid–base ratio(K_(a/b))of *** synergy of Cl−and B_(4)O_(7)2−of electrolyte prevents the passivation of the alloy anode and enables continuous ***,the Ni and Co in the anode products are recovered by sulfation roasting with recovery efficiencies of 85.58%and 95.27%for Ni and Co,***,modulating the alkalinity of the electrolyte for enhancing oxidation/pulverization of alloy scrap anode provides new insight into electrochemically recovering superalloy scraps.

关键词： Superalloy scraps Recycling Molten salt Alkalinity Electrochemical oxidation Cobalt

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Cr-catalyzed allylic C(sp^(3))–H addition to aldehydes enabled by photoinduced ligand-to-metal charge transfer

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Science China Chemistry 2024年第5期67卷 1589-1595页

作者： Xianrong Zeng Feng-hua Zhang Runchen Lai Xiaoyu Lin Zhaobin wang Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Instrumentation and Service Center for Molecular SciencesWestlake UniversityHangzhou 310024China

Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.

关键词： Cr catalysis photoinduced ligand-to-metal charge transfer hydrogen-atom transfer carbonyl addition

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Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research International 2024年第7期31卷 1811-1823页

作者： Zhong-lin wang Zhi-hua Gong Quan Li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

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A Secure Mutual Authentication Protocol Based on Visual Cryptography Technique for IoT-Cloud

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Chinese Journal of Electronics 2024年第1期33卷 43-57页

作者： Brou Bernard Ehui Chen CHEN Shirui wang hua GUO jianwei LIU School of Cyber Sciences and Technology Beihang University State Key Laboratory of Software Development Environment Beihang University Sino-French Engineering School Beihang University Beihang Hangzhou Innovation Institute Yuhang

Because of the increasing number of threats in the IoT cloud, an advanced security mechanism is needed to guard data against hacking or attacks. A user authentication mechanism is also required to authenticate the user accessing the cloud services. The conventional cryptographic algorithms used to provide security mechanisms in cloud networks are often vulnerable to various cyber-attacks and inefficient against new attacks. Therefore,developing new solutions based on different mechanisms from traditional cryptography methods is required to protect data and users’ privacy from attacks. Different from the conventional cryptography method, we suggest a secure mutual authentication protocol based on the visual cryptography technique in this paper. We use visual cryptography to encrypt and decrypt the secret images. The mutual authentication is based on two secret images and *** user requests the ticket from the authentication server(AS) to obtain the permission for accessing the cloud services. Three shared secret keys are used for encrypting and decrypting the authentication process. We analyze the protocol using the Barrows-Abadi-Needham(BAN)-logic method and the results show that the protocol is robust and can protect the user against various attacks. Also, it can provide a secure mutual authentication mechanism.

关键词： Visualization Cloud computing Data privacy Protocols Biometrics (access control) Authentication Resists

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Deep Learning Social Network Access Control Model Based on User Preferences

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 1029-1044页

作者： Fangfang Shan Fuyang Li Zhenyu wang Peiyu ji Mengyi wang Huifang Sun School of Computer Science Zhongyuan University of TechnologyZhengzhou450007China Henan Key Laboratory of Cyberspace Situation Awareness Zhengzhou450001China

A deep learning access controlmodel based on user preferences is proposed to address the issue of personal privacy leakage in social ***,socialusers andsocialdata entities are extractedfromthe social networkandused to construct homogeneous and heterogeneous ***,a graph neural networkmodel is designed based on user daily social behavior and daily social data to simulate the dissemination and changes of user social preferences and user personal preferences in the social ***,high-order neighbor nodes,hidden neighbor nodes,displayed neighbor nodes,and social data nodes are used to update user nodes to expand the depth and breadth of user ***,a multi-layer attention network is used to classify user nodes in the homogeneous graph into two classes:allow access and deny *** fine-grained access control problem in social networks is transformed into a node classification problem in a graph neural *** model is validated using a dataset and compared with other methods without losing *** model improved accuracy by 2.18%compared to the baseline method GraphSAGE,and improved F1 score by 1.45%compared to the baseline method,verifying the effectiveness of the model.

关键词： Graph neural networks user preferences access control social network

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