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Effect of La on the Corrosion Behavior and Mechanism of 3Ni Weathering Steel in a Simulated Marine Atmospheric Environment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 308-324页

作者： Gang Niu Rui Yuan R.d.K.Misra Na Gong Zhi-hui Zhang Hao-xiu Chen hui-Bin Wu Cheng-Jia Shang xin-Ping Mao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Laboratory for Excellence in Advanced Steel Research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX79968USA Institute of Materials Research and Engineering Agency for ScienceTechnologyand ResearchSingapore138634Singapore department of Materials Science and Engineering University of TorontoTorontoONM5S 3E4Canada

The corrosion behavior and mechanism of 3Ni weathering steel in a simulated oceanic atmospheric environment are investigated in order to comprehend the impacts of La,as determined through electrochemical analysis and rust layer *** results of this study demonstrate that the addition of La enhances the corrosion resistance of 3Ni weathering steel in the marine atmospheric environment,thereby reducing the corrosion rate and improving the protection of the rust *** influence of La on corrosion resistance can be attributed to two primary ***,La functions as a grain refiner,minimizing the potential difference of the micro-regions on the substrate surface,thereby significantly reducing the corrosion of bare steel in the marine ***,La inhibits the process of Fe_(3)O_(4) ox.d.tion back toγ-FeOOH during corrosion at the local site,thus decreasing the formation ofγ-FeOOH and enhancing the charge transfer *** research work may serve as a reference for expanding the application of rare earth elements in the field of weathering steel.

关键词： Weathering steel Rare earth Rust layer Corrosion behavior Corrosion resistance

Rapid synthesis of oxygen-defected molybdenum ox.d.s quantum dots as efficient nanozymes for healing diabetic ulcers

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Nano Research 2024年第7期17卷 6376-6385页

作者： Fangjun Cao hui Feng Jiaxin Yao xiang Hou Tiezhi Jin Junfeng hui Shaanxi Key Laboratory of Qinling Ecological Security Shaanxi Institute of ZoologyXi’an 710072China Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing Ministry of EducationSchool of Chemical EngineeringNorthwest UniversityXi'an 710069China Shaanxi Key Laboratory of degradable Biomedical Materials and Shaanxi R&d Center of Biomaterials and Fermentation Engineering School of Chemical EngineeringNorthwest UniversityXi'an 710069China

The continuous inflammatory response in diabetic skin wounds leads to excessive production of reactive oxygen species,which cause a vicious circle of long-term *** the therapeutic research of metal nanoenzymes for healing diabetic ulcers,it still faces the challenges in poor nanoenzymes activity and low-efficient therapeutic ***,ultrasmall oxygen-deficient MoO_(3−x)quantum dots were fabricated and employed as nanoenzymes for healing fiabetic *** PEGylation,PEGylated MoO_(3−x)quantum dots(MoO_(3−x)/PEG)with oxygen vacancies exhibits excellent photothermal,perox.d.se/catalase-like *** addition,these MoO_(3−x)/PEG showed superior properties in scavenging H_(2)O_(2)and effectively inhibiting the scavenging of reactive oxygen *** importantly,such an oxygen-defected MoO_(3−x)/PEG had obvious antibacterial and skin repairing effects on alleviating hypoxia and excessive ox.d.tive stress even in a mouse model of diabetic ulcers,inhibiting proinflammatory cytokines and significantly accelerating the healing of infected wounds,which shows great application potential for promoting wound *** work highlights that the developed oxygen defected molybdenum ox.d. compounds capable of perox.d.selike and catalase-like activities show great application potential for healing diabetes wound.

关键词： oxygen-defected molybdenum-based nanoenzymes antiox.d.nt anti-inflammatory diabetes ulcer wounds

Effect of tungsten carbide particles on microstructure and mechanical properties of Cu alloy composite bit matrix

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Journal of Iron and Steel Research International 2024年第2期31卷 519-530页

作者： ding-qian dong Feng-yuan He xin-hui Chen hui Li Kai-hua Shi hui-wen xiong xin xiang Li Zhang College of Mechanical Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083HunanChina Zigong Cemented Carbide Co. Ltd.Zigong643011SichuanChina Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Science and EngineeringZigong643000SichuanChina

Copper alloy composite bit matrix was prepared by pressureless vacuum infiltration,using at least one of the three kinds of tungsten carbide particles,for example,irregular cast tungsten carbide,monocrystalline tungsten carbide and sintered reduced tungsten carbide *** effects of powder particle morphology,particle size and mass fraction of tungsten carbide on the microstructure and mechanical properties of copper alloy composite were investigated by means of scanning electron microscopy,x-ray diffraction and abrasive wear test in *** results show that tungsten carbide morphology and particle size have obvious effects on the mechanical properties of copper alloy *** tungsten carbide partially dissolved in the copper alloy binding phase,and layers of Cu_(0.3)W_(0.5)Ni_(0.1)Mn_(0.1)C phase with a thickness of around 8–15μm were formed on the edge of the cast tungsten *** 45%irregular crushed fine cast tungsten carbide and 15%monocrystalline cast tungsten carbide were used as the skeleton,satisfactory comprehensive performance of the reinforced copper alloy composite bit matrix was obtained,with the bending strength,impact toughness and hardness reaching 1048 MPa,4.95 J/cm^(2) and 43.6 HRC,*** main wear mechanism was that the tungsten carbide particles firstly protruded from the friction surface after the copper alloy matrix was worn,and then peeled off from the matrix when further wear occurred.

关键词： Polycrystalline diamond compact Pressureless vacuum infiltration Copper alloy composite bit matrix Microstructure characterization Abrasive wear behavior

Principal components of nuclear mass models

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： xin-hui Wu Pengwei Zhao department of Physics Fuzhou UniversityFuzhou 350108China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

An integrative mathematical model of microwave ion thruster for mHz-frequency thrust noise analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 121-136页

作者： xiang NIU hui LIU daren YU Plasma Propulsion Laboratory Harbin Institute of TechnologyHarbin 150001China

Many high-precision space missions need thrusters to produce thrust with low noise to compensate for disturbances and ensure satellite platform stability. Microwave ion thruster is characterized with a wide thrust range and potential for these missions. A cost-effective and accurate mathematical model is crucial for mHz-frequency thrust noise analysis and feedback controller design. The Particle-In-Cell(PIC) and global models are two common simulation tools. The PIC model is characterized with high accuracy but huge computation cost, which is difficult to analyze long-time performance characteristics. Now, the global model is only used for the discharge chamber with low accuracy and cannot reflect ion extraction properties. In this paper, an integrative mathematical model is built for a 1-cm microwave ion thruster and can reflect ion beamlet divergence and impingement on the Accelerator Grid(AG). Simulation results show good agreement with experiments at 0.06 sccm. However, the model demonstrates worse consistency with experiments when the flux increases to 0.1 sccm, which may be because the influence of neutral gas on the Electron Cyclotron Resonance(ECR) is not considered in the model. A long-time(1000 s) simulation is conducted with this model under 35 μN. It takes 3 hrs, and the thrust noise reaches 1 μN/Hz^(0.5) at 1 mHz.

关键词： Electric propulsion Microwave ion thruster Integrative model Sheath property Ion beamlet divergence Thrust noise Plasma

Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 43-55页

作者： xian Zhou Zhengfu Zhang hui Yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Kunming Metallurgical Research Institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the ***,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGdG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were *** was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent *** addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydrox.d.s and non-bridging Si–O and Al–O coordination with silica-aluminate ***_(3)^(3−) was ox.d.zed into AsO_(4)^(3−),which may form Ca–As or Fe–As ***_(2)O_(7)^(2−)was converted to CrO_(4)^(2−)under alkaline environment and then combined with OH−to form Cr(OH)3 ***^(2+)may react directly with dissolved silicate to form Mn_(2)SiO_(4) and also form Mn(OH)_(2) *** unstable Mn(OH)_(2) can be further ox.d.zed to MnO_(2).The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble *** results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

Multi-Level Parallel Network for Brain Tumor Segmentation

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 741-757页

作者： Juhong Tie hui Peng School of Software Engineering Chengdu University of Information TechnologyChengdu610225China

Accurate automatic segmentation of gliomas in various sub-regions,including peritumoral edema,necrotic core,and enhancing and non-enhancing tumor core from 3d multimodal MRI images,is challenging because of its highly heterogeneous appearance and *** convolution neural networks(CNNs)have recently improved glioma segmentation ***,extensive down-sampling such as pooling or stridden convolution in CNNs significantly decreases the initial image resolution,resulting in the loss of accurate spatial and object parts information,especially information on the small sub-region tumors,affecting segmentation ***,this paper proposes a novel multi-level parallel network comprising three different level parallel subnetworks to fully use low-level,mid-level,and high-level information and improve the performance of brain tumor *** also introduce the Combo loss function to address input class imbalance and false positives and negatives imbalance in deep *** proposed method is trained and validated on the BraTS 2020 training and validation *** the validation dataset,ourmethod achieved a mean dice score of 0.907,0.830,and 0.787 for the whole tumor,tumor core,and enhancing tumor core,*** with state-of-the-art methods,the multi-level parallel network has achieved competitive results on the validation dataset.

关键词： Convolution neural network brain tumor segmentation parallel network

From non-carbon host toward carbon-free lithium-sulfur batteries

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Nano Research 2024年第3期17卷 1337-1365页

作者： Yanqi Feng hui Liu Qiongqiong Lu School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China Institute of Materials Henan Key Laboratory of Advanced Conductor MaterialsHenan Academy of SciencesZhengzhou 450046China Leibniz Institute for Solid State and Materials Research(IFW)dresden e.V. Helmholtzstraβe 2001069 DresdenGermany School of Materials&Environment Engineering Chengdu Technological UniversityChengdu 611730China

Lithium-sulfur(Li-S)batteries with advantages of high energy densities(2600 Wh·kg^(-1)/2800 Wh·L^(-1))and sulfur abundance are regarded as promising candidates for next-generation high-energy ***,the conventional carbon host used in sulfur cathodes suffers from poor chemical adsorption towards Li-polysulfides(LPS)in liquid electrolyte and sluggish redox kinetics,leading to low capacity and rate ***,carbon host used in Li metal anode with the intrinsic property of poor lithiophilicity and high Li-nucleation barrier gives rise to uncontrollable dendrite growth and further battery ***,non-carbon hosts with chemical adsorption toward LPS and catalytic activity for accelerating LPS redox conversion as well as lithiophilic property for guiding uniform Li deposition are proposed and demonstrated a high efficiency in both sulfur cathodes and Li metal *** this review,the principle and challenges of Li-S batteries are first presented,then recent work using non-carbon hosts in Li-S batteries is summarized comprehensively,and the mechanism of non-carbon host in improving sulfur utilization and stabilizing Li metal anode is discussed in ***,remaining challenges and outlook on the implementation of non-carbon host for practical carbon-free Li-S batteries are also provided.

关键词： sulfur cathode Li metal anode polysulfides adsorption catalytic effect Li dendrite carbon-free lithium-sulfur batteries

Clinical study on the relationship between liver cirrhosis,ascites,and hyponatremia

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 751-758页

作者： xuan-Ji Li hui-hui Meng department of Gastroenterology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina department of Hepatology Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430065Hubei ProvinceChina

BACKGROUNd Cirrhosis is a common liver disease,and ascites is one of the common clinical ***,the clinical manifestations of ascites combined with hyponatremia as a high-risk condition and its relationship to patient prognosis have not been fully *** To explore the clinical manifestations,prognostic factors,and relationships of ascites with hyponatremia in patients with cirrhosis to provide better diagnostic and treatment *** In this study,we retrospectively analyzed the clinical data of 150 patients diagnosed with cirrhosis and ascites between 2017 and *** were divided into two groups:ascites combined with hyponatremia group and ascites *** compared the general characteristics,degree of hyponatremia,complications,treatment,and prognosis between the two *** In the study results,patients in the ascites combined with hyponatremia group showed an older average age(58.2±8.9 years),64.4%were male,and had a significantly longer hospitalization time(12.7±5.3 d).Hyponatremia was more severe in this group,with a mean serum sodium concentration of 128.5±4.3 mmol/L,which was significantly different from the ascites group of 137.6±2.1 mmol/*** with ascites and hyponatremia were more likely to develop hepatic encephalopathy(56.2%vs 39.0%),renal impairment(45.2%vs 28.6%)and infection(37.0%vs 23.4%).Regarding treatment,this group more frequently used diuretics(80.8%vs 62.3%)and salt supplements(60.3%vs 38.9%).Multiple logistic regression analysis identified older age[Odds ratio(OR)=1.06,P=0.025]and male gender(OR=1.72,P=0.020)as risk factors for hyponatremia combined with ***,patients with ascites and hyponatremia present a clear high-risk status,accompanied by severe complications and poor *** In patients with cirrhosis,ascites with hyponatremia is a high-risk condition that is often associated with severe complications.

关键词： Liver cirrhosis Ascites Hyponatremia Risk Complications