检索结果-南通市图书馆

Segregation of Mg-6Gd alloy under natural convection:From macro solute distribution to micro dendrite growth

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第5期21卷 613-624页

作者： Hong-xu Chen Ang Zhang Hao li yu Gao yu-hong Cui Guang-sheng Huang bin Jiang Fu-sheng Pan National Engineering Research Center for Magnesium Alloys National Key Laboratory of Advanced Casting TechnologiesCollege of Materials Science and EngineeringChongqing UniversityChongqing 400044China

Segregation is a serious defect in alloy ingots which severely deteriorates materials *** segregation defect in Mg-6Gd alloy is studied by coupling macro thermal-solutal-convection transport and micro dendrite *** macroscopic fluid dynamics and mass transfer equations are resolved to forecast the segregation behavior under conditions of continuous temperature variation during the solidification *** numerical model is validated by testing double-diffusive natural convection in a closed square cavity.A phase field model is then applied to simulate the micro dendrite growth,using macro undercooling and liquid flow velocity as boundary *** show that the multiscale segregation behavior,including macro solute distribution and micro dendritic morphology,is strongly dependent on the temperature condition and the liquid convection,which provides guidance for reducing and eliminating the segregation defect.

关键词： magnesium alloy segregation numerical simulation phase-field simulation multiscale

A micro-crosslinked amphoteric hydrophobic association copolymer as high temperature-and salt-resistance fluid loss reducer for water-based drilling fluids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1980-1991页

作者： Jian li yu-Xi Ji Xiao-Xiao Ni Kai-He Lv Xian-bin Huang Jin-sheng Sun School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Key Laboratory of Unconventional Oil&Gas Development China University of Petroleum(East China)Qingdao26650ShandongChina Inspection and Testing Center of Huabei Oil Field Company PetroChinaRenqiu062552HebeiChina Drilling Fluid Research Institute CNPC Engineering Technology R&D Company LimitedBeijing102206China

During ultradeep oil and gas drilling,fluid loss reducers are highly important for water-based drilling fluids,while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtration performance remains a ***,a micro-crosslinked amphoteric hydrophobic association copolymer(i.e.,DADC)was synthesized using N,N-dimethyl acrylamide,diallyl dimethyl ammonium chloride,2-acrylamido-2-methylpropane sulfonic acid,hydrophobic monomer,and pentaerythritol triallyl ether *** to the synergistic effects of hydrogen bonds,electrostatic interaction,hydrophobic association,and micro-crosslinking,the DADC copolymer exhibited outstanding temperature-and *** rheological experiments have shown that the DADC copolymer had excellent shear dilution performance and a certain degree of salt-responsive viscosity-increasing *** DADC copolymer could effectively adsorb on the surface of bentonite particles through electrostatic interaction and hydrogen bonds,which bring more negative charge to the bentonite,thus improving the hydration and dispersion of bentonite particles as well as the colloidal stability of the drilling ***,the drilling fluids constructed based on the DADC copolymer exhibited satisfactory rheological and filtration properties(FLHTHP=12 m L)after aging at high temperatures(up to200℃)and high salinity(saturated salt)***,this work provided new insights into designing and fabricating high-performance drilling fluid treatment agents,demonstrating good potential applications in deep and ultradeep drilling engineering.

关键词： Fluid loss reducer Temperature-and salt-resistance Hydrophobic association Amphoteric Micro-crosslinking

Mitochondrial dysfunction affects hepatic immune and metabolic remodeling in patients with hepatitis B virus-related acute-onchronic liver failure

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第8期30卷 881-900页

作者： yu Zhang Xiao-ling Tian Jie-Qun li Dong-sheng Wu Qiang li bin Chen Department of Hepatology Institute of HepatologyThe First Affiliated Hospital of Hunan University of Chinese MedicineChangsha 410021Hunan ProvinceChina Department of liver Transplant Transplant Medical Research CenterThe Second Xiangya Hospital of Central South UniversityChangsha 410011Hunan ProvinceChina Department of Surgery The First Affiliated Hospital of Hunan University of Chinese MedicineChangsha 410021Hunan ProvinceChina

BACKGROUND Immune dysregulation and metabolic derangement have been recognized as key factors that contribute to the progression of hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF).However,the mechanisms underlying immune and metabolic derangement in patients with advanced HBV-ACLF are *** To identify the bioenergetic alterations in the liver of patients with HBV-ACLF causing hepatic immune dysregulation and metabolic *** liver samples were collected from 16 healthy donors(HDs)and 17 advanced HBV-ACLF patients who were eligible for liver *** mitochondrial ultrastructure,metabolic characteristics,and immune microenvironment of the liver were *** focus was given to organic acid metabolism as well as the function and subpopulations of macrophages in patients with *** Compared with HDs,there was extensive hepatocyte necrosis,immune cell infiltration,and ductular reaction in patients with *** patients,the liver suffered severe hypoxia,as evidenced by increased expression of hypoxia-inducible factor-1α.Swollen mitochondria and cristae were observed in the liver of *** number,length,width,and area of mitochondria were adaptively increased in *** metabolomics analysis revealed that mitochondrial oxidative phosphorylation decreased,while anaerobic glycolysis was enhanced in patients with *** findings suggested that,to a greater extent,hepa-tocytes used the extra-mitochondrial glycolytic pathway as an energy *** with HBV-ACLF had elevated levels of chemokine C-C motif ligand 2 in the liver homogenate,which stimulates peripheral monocyte infiltration into the *** and functional analysis of macrophage subsets revealed that patients with ACLF had a high abundance of CD68^(+)HLA-DR^(+)macrophages and elevated levels of both interleukin-1βand transforming growth factor-β1 in their *** abundance of CD206^(+)CD163^(+)macrophag

关键词： Acute-on-chronic liver failure Hypoxia-inducible factor-1α Mitochondria Metabolic phenotype Immune cells

Dynamic Vision-Based Machinery Fault Diagnosis With Cross-Modality Feature Alignment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2068-2081页

作者： Xiang li Shupeng yu Yaguo Lei Naipeng li bin Yang Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China IEEE

Intelligent machinery fault diagnosis methods have been popularly and successfully developed in the past decades,and the vibration acceleration data collected by contact accelerometers have been widely *** many industrial scenarios,contactless sensors are more *** event camera is an emerging bio-inspired technology for vision sensing,which asynchronously records per-pixel brightness change polarity with high temporal resolution and low *** offers a promising tool for contactless machine vibration sensing and fault ***,the dynamic vision-based methods suffer from variations of practical factors such as camera position,machine operating condition,***,as a new sensing technology,the labeled dynamic vision data are limited,which generally cannot cover a wide range of machine fault *** at these challenges,a novel dynamic vision-based machinery fault diagnosis method is proposed in this *** is motivated to explore the abundant vibration acceleration data for enhancing the dynamic vision-based model performance.A crossmodality feature alignment method is thus proposed with deep adversarial neural networks to achieve fault diagnosis knowledge *** event erasing method is further proposed for improving model robustness against *** proposed method can effectively identify unseen fault mode with dynamic vision *** on two rotating machine monitoring datasets are carried out for validations,and the results suggest the proposed method is promising for generalized contactless machinery fault diagnosis.

关键词： Condition monitoring domain generalization eventbased camera fault diagnosis machine vision

The Principle of Calibration Using the Ionic Current——A New Calibration Method for Electro-Magnetic Flowmeters

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 1998年第2期2卷 38-42页

作者： li bin sheng yu (School of Automation)

An equivalent relationship between electro magnetic flowmeters (EMFs) and the Hall effect is discussed in principle and three equivalent conclusions about their measuring equations are derived. Thereby,the calibration using the ionic current (CUIC) is introduced to the calibration of EMFs in a special Hall effect system. A basic system with these equations is specially given and discussed for realizing the method. Two key points about CUIC are proved by a simple experiment.

关键词： calibration of EMFs equivalent relationship between EMFs and Hall effect ionic current being equivalent to the real flowrate of an EMF

Engineering Ru（N^N）3-modified covalent organic framework for photocatalytic olefin epoxidation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3719-3728页

作者： Yan-lin li sheng-li Huang Guo-yu Yang Key Laboratory of Cluster Science (Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical Engineering Beijing Institute of Technology

Photocatalytic olefin oxidation using air as an oxidant is an environmentally friendly method for producing epoxides. Covalent organic frameworks（COFs） have emerged as promising photocatalysts in various organic synthesis reactions. The combination of tri-（2-pyridinal aldehyde）-containing precursor with 4,4’,4’’-（1,3,5-triazine-2,4,6-triyl）trianiline generated（N^N）-I-COF. Via imine-to-quinoline transformation and coordination anchorage of Ru（N^N）3unit, Ru（N^N）3@Q-COF was obtained with improved chemical stability, skeleton conjugation, and novel photochemical characteristics, and demonstrated excellent photocatalytic activity in olefin epoxidation with a wide range of substrates. The presence of H2O played a crucial role in the formation of reactive oxygen species（ROSs）, which in turn influenced the olefin oxidation process. The hydrophilicity of Ru（N^N）3facilitated the approach of H2O and O2to the photogenerated charges, thereby promoting ROSs generation. The lipophilicity of Q-COF allowed for the absorption of olefin substrates, and its nano-channels increased encountering possibility between olefins and ROSs. Consequently, Ru（N^N）3@Q-COF provided an intriguing platform for olefin photooxidation and could be recycled multiple times without any degradation in performance. This report revealed that the conversion of classical ROSs into less potent oxidants with rapid kinetic rates played a crucial role in achieving highly efficient and selective epoxidation of terminal olefins.

关键词： polypyridyl Ru covalent organic framework olefin epoxidation photocatalysis

Interaction mechanism between BaZrO_(3)/Y_(2)O_(3) refractory and Ti_(2)Ni alloy melts

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1376-1388页

作者： Xiao Hou Guang-yao Chen Jian liu Ming-rui Lv Fei-hai yu Qi-sheng Feng Rong-bin li Xiong-gang Lu Chong-he li State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferromeallurgy and School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Shanghai Special Casting Engineering Technology Research Center Shanghai 201605China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100ZhejiangChina School of Materials Science and Engineering Shanghai DianJi UniversityShanghai 201306China

The titanium alloys with highly chemical activity require stable crucible refractories that can withstand the erosion of alloy *** phase composition and microstructure are crucial factors that affect the stability of the refractory *** effect of Y_(2)O_(3) on the composition and microstructure of BaZrO_(3) crucible was systematically investigated,and the improved mechanism of the stability of BaZrO_(3)/Y_(2)O_(3) crucible was clarified in comparison with the BaZrO_(3) *** results showed that the erosion layer thickness of the BaZrO_(3)/Y_(2)O_(3) crucible was only 63μm,which was far less than that in the BaZrO_(3) crucible(485μm),and the erosion layer in the BaZrO_(3)/Y_(2)O_(3) crucible also exhibited a higher density than that in the BaZrO_(3) *** the sintering,Y_(2)O_(3) could improve the densification of the BaZrO_(3) crucible due to the solid solution effect between Y_(2)O_(3) and ZrO_(2),which also caused the evaporation of BaO,resulting in the generation of a Y_(2)O_(3)(ZrO_(2))film on the surface of the ***,the Y_(2)O_(3)(ZrO_(2))had higher thermodynamic stability than Y_(2)O_(3),confirming that the BaZrO_(3)/Y_(2)O_(3) crucible with high density exhibited a superior erosion resistance to titanium *** dual-phase structure provides a strategy to design a long-life and stable refractory for melting titanium alloys.

关键词： Barium zirconate Yttrium oxide Dual-phase refractory Titanium alloy Interaction

A direct electrochemical biosensor for rapid glucose detection based on nitrogen-doped carbon nanocages

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2184-2192页

作者： Lan-Lan li yu Zhao li-Jia Pan Jian-bin Xu Yi Shi College of Mechanical and Electrical Engineering Henan Agricultural UniversityZhengzhou 450002China School of Electronic Science and Engineering Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China Department of Electronic Engineering The Chinese University of HongKongHongkong 999077China

Given the increasing number of diabetic patients,rapid and accurate detection of glucose in body fluids is *** study developed a direct electrochemical biosensor for glucose based on nitrogen-doped carbon nanocages(NCNCs).NCNCs possess a large specific surface area of 1395 m^(2)·g^(-1),a high N atomic content of 9.37%and good biocompatibility,which is favorable for enzyme loading and electron *** surface average concentration of electroactive glucose oxidase on NCNCs was 2.82×10^(-10)mol·cm^(-2).The NCNC-based direct electrochemical biosensor exhibited a high sensitivity of 13.7μA·(mmol·L^(-1))^(-1)·cm^(-2),rapid response time of 5 s and an impressive electron-transferrate constant(ks)of 1.87 s^(-1).Furthermore,we investigated an NCNC-based direct electron transfer(DET)biosensor for sweat glucose detection,which demonstrated tremendous promise for non-invasive wearable diabetes diagnosis.

关键词： Direct electron transfer(DET) Nitrogen-doped carbon nanocages(NCNCs) Glucose oxidase Biosensor

Spin transport of half-metal Mn_(2)X_(3) with high Curie temperature:An ideal giant magnetoresistance device from electrical and thermal drives

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 125-135页

作者： bin liu Xiaolin Zhang Jingxian Xiong Xiuyang Pang sheng liu Zixin Yang Qiang yu Honggen li Sicong Zhu Jian Wu Hubei Province Key Laboratory of Systems Science in Metallurgical Process The State Key Laboratory for Refractories and MetallurgyCollaborative Innovation Center for Advanced SteelsInternational Research Institute for Steel TechnologyWuhan University of Science and TechnologyWuhan 430081China Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physical and Technology Wuhan UniversityWuhan 430072China College of Advanced Interdisciplinary Studies Nanhu Laser LaboratoryNational University of Defense TechnologyChangsha 410073China Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore i-Lab&Key Laboratory of Nanodevices and Applications&Key Laboratory of Nanophotonic Materials and Devices Suzhou Institute of Nano-Tech and NanoBionicsChinese Academy of SciencesSuzhou 215123China Institute of Optical Science and Technology School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China

Currently,magnetic storage devices are encountering the problem of achieving lightweight and high integration in mobile computing devices during the information *** a result,there is a growing urgency for twodimensional half-metallic materials with a high Curie temperature(TC).This study presents a theoretical investigation of the fundamental electromagnetic properties of the monolayer hexagonal lattice of Mn_(2)X_(3)(X=S,Se,Te).Additionally,the potential application of Mn_(2)X_(3) as magneto-resistive components is *** three of them fall into the category of ferromagnetic *** particular,the Monte Carlo simulations indicate that the TC of Mn2S3 reachs 381 K,noticeably greater than room *** findings present notable advantages for the application of Mn2S3 in spintronic ***,a prominent spin filtering effect is apparent when employing non-equilibrium Green’s function simulations to examine the transport *** resulting current magnitude is approximately 2×10^(4) nA,while the peak gigantic magnetoresistance exhibits a substantial value of 8.36×10^(16)%.It is noteworthy that the device demonstrates a substantial spin Seebeck effect when the temperature differential between the electrodes is *** brief,Mn_(2)X_(3) exhibits outstanding features as a highTC half-metal,exhibiting exceptional capabilities in electrical and thermal drives spin ***,it holds great potential for usage in spintronics applications.

关键词： half-metals Mn_(2)X_(3) high Curie temperature electrical and thermal GMR