检索结果-南通市图书馆

mechanical properties and in vivo biodegradability of mg-Zr-Y-Nd-La magnesium alloy produced by a combined severe plastic deformation

引用

Rare metals 2021年第3期40卷 651-662页

作者： A.Torkian g.Faraji m.S.Pedram School of mechanical Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran Department of Veterinary Surgery and Radiology Faculty of Veterinary MedicineUniversity of Tehran14199-63111Iran

Permanent implants are going to be replaced by the implementation of biodegradable magnesium-based implants in fixation of internal bone fractures because of many concerns associated with conventional ***,biodegradable magnesium-based biomaterials exhibit higher biodegradation rate and low mechanical properties which are the main *** work aims to almost overcome both disadvantageous by grain refining of a WE43 magnesium alloy containing 93.04 wt% mg,4.12 wt% Y,2.15 wt% Nd,0.43 wt% Zr,and 0.26 wt%*** this study,the consequences of combined severe plastic deformation(SPD) on the mechanical properties,microstructure,and in vivo degradation behavior of WE43 magnesium alloy were *** do so,WE43 magnesium alloy was chosen and processed through multipass equal channel angular pressing(ECAP) at 330℃ for up to four passes followed by an extrusion *** results showed that higher strength and hardness with minimum ductility less was obtained in the sample processed via two-pass ECAP followed by *** vivo biodegradation experiments showed higher degradation rate for the unprocessed coarse-grained(Cg) WE43 *** two-pass ECAP and extruded sample with ultrafine-grained(UFg) structure exhibited the lowest in vivo biodegradation rate besides appropriate mechanical *** may be concluded that the WE43 magnesium alloy processed via two-pass ECAP and extrusion could be a very promising candidate for biodegradable implants from both mechanical and biocorrosion viewpoints.

关键词： Implant Severe plastic deformation WE43 grain refinement Hardness mechanical properties

来源：

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

Regulator of g protein signaling 6 mediates exercise-induced recovery of hippocampal neurogenesis,learning,and memory in a mouse model of Alzheimer’s disease

引用

Neural Regeneration Research 2025年第10期20卷 2969-2981页

作者： mackenzie m.Spicer Jianqi Yang Daniel Fu Alison N.DeVore marisol Lauffer Nilufer S.Atasoy Deniz Atasoy Rory A.Fisher Department of Neuroscience and Pharmacology University of Iowa Carver College of MedicineIowa CityIAUSA Iowa Neuroscience Institute University of Iowa Carver College of MedicineIowa CityIAUSA Interdisciplinary graduate Program in molecular medicine University of Iowa Carver College of MedicineIowa CityIAUSA Neural Circuits and Behavior Core University of Iowa Carver College of MedicineIowa CityIAUSA

Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s *** hippocampal neurogenesis is reduced in patients with Alzheimer’s *** stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s ***,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly ***,regulator of g protein signaling 6(RgS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in ***,we generated novel RgS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RgS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse *** found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control *** cognitive rescue was abolished by RgS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal *** hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RgS6 deletion in dentate gyrus neural precursor ***6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RgS6-expressing ***,RgS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RgS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.

关键词： adult hippocampal neurogenesis Alzheimer’s disease dentate gyrus exercise learning/memory neural precursor cells regulator of g protein signaling 6(RgS6)

来源：

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

mineralogical, REE-geochemical and fluid inclusion studies on some uranium occurrences, gabal gattar, Northeastern Desert, Egypt

引用

Chinese Journal Of geochemistry 2011年第4期30卷 430-443页

作者： El-Feky m.g. Nuclear materials Authority

Altered granite occurrences (gII and gV) at gabal (g.) gattar are the most important mineralized rocks hosting U-mineralization in Egypt. This mineralized granite is affected by multi-stage hydrothermal alteration proc-esses along brittle structures. This alteration comprises pre-ore alkali-metasomatism and ore-stage hydrothermal hematitization, silicification, kaolinitization, fluoritization, carbonatization and episyenitization. Autoradiographic examination indicates that primary uranium mineralization is present as massive or disseminated ores along tectonic fractures, interstitially in granular minerals, and as cements of breccias. Uraninite, pitchblende and coffinite are the main primary minerals, while uranophane and kasolite are the secondary ones. galena, chalcopyrite, pyrrohtite and pyrite are the most abundant sulphides in association with uranium mineralizations. Hydrothermal alterations at the gII occurrence exhibit an increase in Ni, Cu, Zn, Pb, mo, Nb, Rb beside HREEs and a decrease in Ba, Co, Sr, and V, while alterations at the gV occurrence show enrichment in Ni, Cu, Pb, mo, Nb, Y, HREEs and depletion in Zn, Ba, Co, Rb, Sr, and V. Hydrothermal alteration during the late magmatic stage is also identified through the development of unusual REE patterns and fractionation of ratios like Zr/Hf and Y/Ho out of the CHARAC (Charge Radius Con-trolled) range. Non-chondritic Y/Ho ratio at gV is of larger value than chondritic one which may result from wa-ter-rock interaction or print from the encompassing sedimentary rocks. Fluid inclusion studies on quartz and fluorite revealed that temperatures of the mineralizing fluids range between 126 and 240℃ at pressure ≤0.5×108 Pa and give salinity values ranging between 1 wt% and 7.8 wt% NaCl equivalent.

关键词：稀土元素地球化学流体包裹体铀矿化矿物学埃及全球信息基础设施东北部沙漠

来源：

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

Quinpi:Integrating Conservation Laws with CWENO Implicit methods

引用

Communications on Applied mathematics and Computation 2023年第1期5卷 343-369页

作者： g.Puppo m.Semplice g.Visconti Dipartimento di matematica UniversitàLa SapienzaP.le Aldo Moro500185 RomaItaly Dipartimento di Scienza e Alta Tecnologia Universitàdell'InsubriaVia Valleggio1122100 ComoItaly

many interesting applications of hyperbolic systems of equations are stiff,and require the time step to satisfy restrictive stability *** way to avoid small time steps is to use implicit time *** integration is quite straightforward for first-order *** order schemes instead also need to control spurious oscillations,which requires limiting in space and time also in the linear *** propose a framework to simplify considerably the application of high order non-oscillatory schemes through the introduction of a low order implicit predictor,which is used both to set up the nonlinear weights of a standard high order space reconstruction,and to achieve limiting in *** this preliminary work,we concentrate on the case of a third-order scheme,based on diagonally implicit Runge Kutta(DIRK)integration in time and central weighted essentially non-oscillatory(CWENO)reconstruction in *** numerical tests involve linear and nonlinear scalar conservation laws.

关键词： Implicit schemes Essentially non-oscillatory schemes Finite volumes WENO and CWENO reconstructions

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cellular and molecular mechanisms in the pathogenesis of liver fibrosis:An update

引用

World Journal of gastroenterology 2014年第23期20卷 7260-7276页

作者： gülsüm ?zlem Elpek Department of Pathology Akdeniz University Medical School07070 AntalyaTurkey

There have been considerable recent advances towards a better understanding of the complex cellular and molecular network underlying liver *** data indicate that the termination of fibrogenic processes and the restoration of deficient fibrolytic pathways may allow the reversal of advanced fibrosis and even ***,efforts have been made to better clarify the cellular and molecular mechanisms that are involved in liver *** of hepatic stellate cells(HSCs)remains a central event in fibrosis,complemented by other sources of matrix-producing cells,including portal fibroblasts,fibrocytes and bone marrow-derived *** cells converge in a complex interaction with neighboring cells to provoke scarring in response to persistent *** the interaction of different cell types,revealing the effects of cytokines on these cells and characterizing the regulatory mechanisms that control gene expression in activated HSCs will enable the discovery of new therapeutic ***,the characterization of different pathways associated with different etiologies aid in the development of disease-specific *** article outlines recent advances regarding the cellular and molecular mechanisms involved in liver fibrosis that may be translated into future *** pathogenesis of liver fibrosis associated with alcoholic liver disease,non-alcoholic fatty liver disease and viral hepatitis are also discussed to emphasize the various mechanisms involved in liver fibrosis.

关键词： Liver Liver fibrosis Cirrhosis Fibrogenesis Hepatic stellate cells myofibroblast Extracellular matrix

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ocellar lamprophyre dyke bearing mineralization,Wadi Nugrus,Eastern Desert,Egypt:geology,mineralogy and geochemical implications

引用

Chinese Journal Of geochemistry 2010年第4期29卷 383-392页

作者： Ibrahim m.E. Saleh g.m. Dawood N.A. Aly g.m. Nuclear materials Authority P.O.Box 530El-MaadiCairoEgypt

The ocellar lamprophyre dyke(ENE-WSW) is recorded at Wadi Nugrus,Eastern Desert,*** cuts porphyritic biotite granites and varies in thickness from 0.5 to 1.5 m and up to 3 km in *** lamprophyre dyke has been altered,and it is characterized by porphyritic and panidiomorphic textures with plagioclase,olivine,and augite constituting the porphyritic phase in a fine groundmass of the same ***,titanite,apatite,fluorite,graphite,calcite,allanite,autunite and Fe-Ti oxides are accessory ***,chlorite and epidote are secondary *** and hematitization are *** to sub-rounded porphyritic and zoned ocelli with radiate or brush-like shapes are generally common and represent physical traps for *** ocellar features are interpreted to represent the late stage of magmatic segregation or magmatic crystallization involving two immiscible magmatic *** studies of altered lamprophyre samples,based on X-ray diffraction(XRD) and environmental scanning electron microscopy(ESEm),indicate the presence of secondary uranium minerals(autunite and uranophane),associated with gold,silver,nickel,atacamite,molybdenum,pyrite and *** presence of kaolinite indicates a high temperature *** mixing of volatile fluids with meteoric water and fluid-wall rock interaction result in changes of pH and oxygen activity and deposition of base metals in reducing environs(graphite and pyrite).Precipitation of hematite probably decreased the pH of the solution and rose acidic *** sudden change in pH and temperature of the fluids would lead to destabilization of base metal complexes favoring their *** magma source of the Nugrus lamprophyre is determined to be between calc-alkaline and alkaline and it has HKCAB and shoshonitic nature and may be derived from decomposition melting of such a metasomatised lithospheric *** is a major fractional phase to account for a rapid

关键词：煌斑岩脉矿物学地球化学沙漠埃及地质学黑云母花岗岩矿化

来源：

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

X-Ray Radiation Sensing Properties of ZnS Thin Film:A Study on the Effect of Annealing

引用

Chinese Physics Letters 2017年第7期34卷 262-265页

作者： m.P.Sarma J.m.Kalita g.Wary Department of Physics Cotton College Guwahati 781001 India Department of Physics and Electronics Rhodes University Grahamstown 6140 South Africa

Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath deposition technique. The chemically synthesized ZnS films are annealed at 333, 363 and 393K for 1 h. Structural analyses show that the lattice defects in the films decrease with annealing. Further, the band gap is also found to decrease from 3.38 to 3.21 eV after annealing at 393K. Current-voltage characteristics of the films are studied under dark and x-ray irradiation conditions. Due to the decrease of lattice defects and band gap, the conductivity under dark conditions is found to increase from 2.06 × 10^-6 to 1.69 × 10^-5 S/em, while that under x-ray irradiation increases from 4.13 × 10^-5 to 5.28 ×10^-5 S/cm. On the other hand, the x-ray radiation detection sensitivity of the films is found to decrease with annealing. This decrease of detection sensitivity is attributed to the decrease of the band gap as well as some structural and surface morphological changes occurring after annealing.

关键词： ZnS X-Ray Radiation Sensing Properties of ZnS Thin Film:A Study on the Effect of Annealing

来源：

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

Nonlinear dynamic analysis of moving bilayer plates resting on elastic foundations

引用

Applied mathematics and mechanics(English Edition) 2020年第3期41卷 439-458页

作者： m.ESmAEILZADEH m.KADKHODAYAN S.mOHAmmADI g.J.TURVEY Department of mechanical Engineering Mashhad BranchAzad UniversityMashhad ***Iran Department of mechanical Engineering Ferdowsi University of MashhadMashhad ***Iran Engineering Department Lancaster UniversityBailriggLancaster LA14YRU.K.

The aim of this study is to investigate the dynamic response of axially moving two-layer laminated plates on the Winkler and Pasternak foundations. The upper and lower layers are formed from a bidirectional functionally graded(Fg) layer and a graphene platelet(gPL) reinforced porous layer, respectively. Henceforth, the combined layers will be referred to as a two-dimensional(2D) Fg/gPL plate. Two types of porosity and three graphene dispersion patterns, each of which is distributed through the plate thickness,are investigated. The mechanical properties of the closed-cell layers are used to define the variation of Poisson’s ratio and the relationship between the porosity coefficients and the mass density. For the gPL reinforced layer, the effective Young’s modulus is derived with the Halpin-Tsai micro-system model, and the rule of mixtures is used to calculate the effective mass density and Poisson’s ratio. The material of the upper 2D-Fg layer is graded in two directions, and its effective mechanical properties are also derived with the rule of mixtures. The dynamic governing equations are derived with a first-order shear deformation theory(FSDT) and the von Kármán nonlinear theory. A combination of the dynamic relaxation(DR) and Newmark’s direct integration methods is used to solve the governing equations in both time and space. A parametric study is carried out to explore the effects of the porosity coefficients, porosity and gPL distributions, material gradients, damping ratios, boundary conditions, and elastic foundation stiffnesses on the plate response. It is shown that both the distributions of the porosity and graphene nanofillers significantly affect the dynamic behaviors of the plates. It is also shown that the reduction in the dynamic deflection of the bilayer composite plates is maximized when the porosity and gPL distributions are symmetric.

关键词： moving laminated plate bidirectional functionally graded material(Fgm) graphene nanoplatelet porosity first-order shear deformation theory(FSDT) Newmark’s integration method

来源：

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

Location Prediction for Improved Human Safety at Complex Environments

引用

Computers, materials & Continua 2022年第6期71卷 5219-5234页

作者： S.g.Siddharth g.m.Tamilselvan C.Venkatesh Department of Electrical and Electronics Engineering Angel College of Engineering and TechnologyTirupurTamilnaduIndia Department of Electronics and Communication Engineering Sri Krishna College TechnologyCoimbatoreTamilnaduIndia Department of Electronics and Communication Engineering KGISL Institute of TechnologyCoimbatoreTamilnaduIndia

In underground operation,primary consideration is *** recent decades,for minimizing accident and for preventing major economic losses and casualties,wireless sensors are used by various large mineral countries through early *** Improved DV-Hop Localization Algorithm(IDVHLA)is used in existing works for doing ***,accurate anchor node detection is impossible in existing works with the malicious nodes presence,where there won’t be any accurate sharing of anchor node’s location *** case of emergency situation,faster communication is a highly complex one.A technique calledmodified Distance Vector Hop based multipath Routing Protocol(mDVHmRP)is introduced in this proposed research work for resolving *** this work,to detect anchor node position,a modified Distance Vector Hop technique is *** research work considers time taken and session time for computing neighbour node’s presence in addition to hop count *** nodes presence can be avoided by considering session time in neighbour node presence *** alert message are send by people in emergency crisis to sever in initial *** Dynamic Source Routing(DSR)routing protocol is used for doing immediate route path *** case of route path failure,for ensuring uninterrupted communication and faster communication,this work introduces amulti path *** distance vector hop technique is used for predicting anchor node location information and predicted information will be *** NS2 simulation environment,overall evaluation of this research work is carried *** compared with available techniques,localization accuracy is enhanced by proposed technique as proven in experimental results.

关键词： Distance vector hop uninterrupted communication multipath routing anchor node localization

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Role of Chloride Ion and Dissolved Oxygen in Electrochemical Corrosion of AA5083-H321 Aluminum-magnesium Alloy in NaCl Solutions under Flow Conditions

引用

Journal of materials Science & Technology 2007年第5期23卷 623-628页

作者： K.Jafarzadeh T.Shahrabi S.m.m.Hadavi m.g.Hosseini Department of materials Engineering.Tarbiat modares University TehranIran Faculty of material Engineering Malek Ashtar UniversityTehranIran Electrochemistry Research Lab. Chemistry FacultyTabriz UniversityTabrizDan

Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCI solutions. Electrochemical tests were carried out at flow velocities of 0, ：2, 5, 7 and 10 m/s, in aerated and deaerated NaCI solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.

关键词： Corrosion Flow NaCl solution AA5083-H321 aluminum-magnesium alloy Chloride ion Oxygen

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：