检索结果-南通市图书馆

慢性应激加重动脉粥样硬化小鼠心肌损伤的模型评价及机制研究

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

中国病理生理杂志 2024年第9期40卷 1635-1644页

作者：倪萍刘思彤孙瑞鸽马海钧孙红张欢梁健杜成渝于游于睿辽宁中医药大学辽宁沈阳110847 辽宁中医药大学附属第二医院辽宁沈阳110031

目的:探究慢性应激对动脉粥样硬化(atherosclerosis,AS)小鼠心肌损伤的影响并揭示其潜在机制。方法:选用SPF级8周龄雄性C57BL/6j小鼠和ApoE^(−/−)小鼠。10周饮食干预后进行AS病理观察,AS鉴定成模后再复合慢性不可预计温和刺激(chronic u... 详细信息

目的:探究慢性应激对动脉粥样硬化(atherosclerosis,AS)小鼠心肌损伤的影响并揭示其潜在机制。方法:选用SPF级8周龄雄性C57BL/6j小鼠和ApoE^(−/−)小鼠。10周饮食干预后进行AS病理观察,AS鉴定成模后再复合慢性不可预计温和刺激(chronic unpredictable mild stress,CUMS)6周,分为五组:对照(control)组、CUMS组、AS-普通饲料喂养(AS-regular diet,AS-r)+CUMS组、AS-高脂饲料喂养(AS-high-fat diet,AS-h)组和AS-h+CUMS组,每组各10只。CUMS期间对各组小鼠进行旷场实验、糖水偏好实验;采用全自动生化分析仪检测小鼠血脂;HE、油红O染色评估主动脉根部病理改变;超声心动图评估小鼠心功能;ELiSA法检测小鼠血清心肌损伤标志物含量、心肌组织ATP含量;透射电镜观察心肌线粒体超微结构;Oxygraph-2k高分辨呼吸能量代谢仪检测心肌线粒体耗氧率;Western blot检测B细胞淋巴瘤蛋白2(B-cell lymphoma-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2-associated X protein,Bax)和cleaved caspase-3蛋白表达。结果:与control组相比各CUMS组运动总路程、进入中央区次数、糖水偏好率均显著下降(Pr+CUMS心肌线粒体结构破坏,ATP含量显著下降(Pi支持的呼吸、线粒体呼吸链复合物Ⅰ+Ⅱ支持的呼吸和电子传递系统最大呼吸能力均显著下降(P<0.05);Bax和cleaved caspase-3蛋白表达显著升高(P<0.05),Bcl-2蛋白表达显著降低(P<0.05)。结论:慢性应激通过破坏AS小鼠心肌线粒体结构及能量代谢功能导致线粒体非稳态负荷发生,进而加剧心肌细胞凋亡加重心肌损伤。

关键词：动脉粥样硬化慢性应激心肌损伤线粒体线粒体非稳态负荷

Shear-accelerated crystallization of glass-forming metallic liquids in high-pressure die casting

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2022年第22期117卷 146-157页

作者： L.H.Liu W.j.Gao X.S.Huang T.Zhang Z.Y.Liu C.Yang W.W.Zhang W.r.Li L.Li P.j.Li National Engineering research Center of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou510640China Department of Mechanical Engineering Tsinghua UniversityBeijing100084China institute of Eontech New Materials Co. Ltd.Dongguan523662China Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen518060China

As one of the most important forming technologies for industrial bulk metallic glass (BMG) parts withcomplex shapes, high-pressure die casting (HPDC) can fill a die cavity with a glass-forming metallic liquidin milliseconds. However, to our knowledge, the correlation between flow and crystallization behavior inthe HPDC process has never been established. in this study, we report on the solidification behavior ofZr_(55)Cu_(30)ni_(5)Al_(10) glass forming liquid under various flow rates. Surprisingly, the resulting alloys display adecreasing content of amorphous phase with increase of flow rate, i.e. increase of cooling rate, suggestingthat crystallization kinetics of glass-forming metallic liquids in the HPDC process is strongly dependenton the flow field. Analysis reveals that the accelerated crystallization behavior is mainly ascribed to therapid increase in viscosity with a decreasing temperature as well as to the huge shear effect in the glassforming liquid at the end stage of the filling process when the temperature is close to the glass-transitionpoint;this results in a transition from diffusion- to advection-dominated transport. The current investigation suggests that flow-related crystallization must be considered to assess the intrinsic glass-formingability of BMGs produced via HPDC. The obtained results will not only improve the understanding ofcrystallization dynamics but also promote the high-quality production and large-scale application of BMGparts.

关键词： Crystallization Shear Supercooled liquid High pressure die casting

The Emeishan large igneous province:A synthesis

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2014年第3期5卷 369-394页

作者： j.Gregory Shellnutt National Taiwan Normal University Department of Earth Science

The late Permian Emeishan large igneous province （EL1P） covers -0.3× 10-6 kmL of the western margin of the Yangtze Block and Tibetan Plateau with displaced, correlative units in northern Vietnam （Song Da zone）. The ELiP is of particular interest because it contains numerous world-class base metal deposits and is contemporaneous with the late Capitanian （-260 Ma） mass extinction. The flood basalts are the signature feature of the ELiP but there are also ultramafic and silicic volcanic rocks and layered mafic- ultramafic and silicic plutonic rocks exposed. The EL1P is divided into three nearly concentric zones （i.e. inner, middle and outer） which correspond to progressively thicker crust from the inner to the outer zone. The eruptive age of the ELiP is constrained by geological, paleomagnetic and geochronological evidence to an interval of 〈3 Ma. The presence of picritic rocks and thick piles of flood basalts testifies to high temperature thermal regime however there is uncertainty as to whether these magmas were derived from the subcontinental lithospheric mantle or sub-lithospheric mantle （i.e. asthenosphere or mantle plume） sources or both. The range of Sr （isr ≈ 0.7040-0.7132）, Nd （ENd（t） ≈ -14 tO ＋8）, Pb （206-pb/204-pb1 ≈ 17.9-20.6） and Os （Yos ≈ -5 to ＋11） isotope values of the ultramafic and mafic rocks does not permit a conclusive answer to ultimate source origin of the primitive rocks but it is clear that some rocks were affected by crustal contamination and the presence of near-depleted isotope compo- sitions suggests that there is a sub-lithospheric mantle component in the system. The silicic rocks are derived by basaltic magmas/rocks through fractional crystallization or partial melting, crustal melting or by interactions between mafic and crustal melts. The formation of the Fe-Ti-V oxide-ore deposits is probably due to a combination of fractional crystallization of Ti-rich basalt and fluxing of C02-rich fluids whereas the ni-Cu-（PGE） deposits are related

关键词： Late Permian Mantle plume Large igneous province Flood basalts Mineral deposits Uplift and doming

Effect of the catalyst preparation method on the performance of ni-supported catalysts for the synthesis of saturated amines from nitrile hydrogenation

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Catalysis 2019年第11期40卷 1693-1703页

作者： D.j.Segobia A.F.Trasarti C.r.Apesteguía Catalysis Science and Engineering research Group (GiCiC) INCAPE UNL-CONICET CCT Conicet- Paraje El Pozo(3000) Santa Fe Argentina

The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported ni catalysts prepared by either incipient-wetness impregnation (ni/SiO2-i) or ammonia (ni/SiO2-A) methods. A ni/SiO2-Al2O3-i sample was also used. ni/SiO2-i was a non-acidic catalyst containing large ni^0 particles of low interaction with the support, while ni/SiO2-A was an acidic catalyst due to the presence of ni^2+ species in ni phyllosilicates of low reducibility. ni/SiO2-i formed essentially butylamine (80%), and dibutylamine as the only byproduct. in contrast, ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to ni^0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.

关键词： nitrile hydrogenation Saturated amines ni-supported catalysts ni-phyllosilicates Catalyst preparation

Dispersion of niquel on the microstructure in magnesium based alloys for hydrogen storage

在线全文

学校读者我要写书评

暂无评论

journal of Magnesium and Alloys 2013年第4期1卷 292-296页

作者： A.A.Zaldıvar-Cadena i.Dıaz-Pena j.G.Cabanas-Moreno Universidad Autonoma de Nuevo Leon Av.Universidad s/nFacultad de Ingenierıa CivilSan Nicolas de los Garza N.L.C.P.66451Mexico instituto Politecnico Nacional UPALMCol.LindavistaC.P.07338 Mexico D.F.Mexico

Mg–Xwt.%ni(X=5 and 20)alloys have been prepared by mechanical alloying using milling times of 15 and 30 h in a planetary ball milling to know the effects of magnesium with the addition of ni as catalyst,dispersion on the microstructure,area surface and the efficiency of hydrogen ***-EDS,XrD and imagej^(■)software have been used to characterize the microstructure and chemical composition of the *** experiments were performed as batch-type tests at 200,250 and 300℃ under 2 MPa H2 pressure during 30 *** experiments resulted in varying amounts of MgH2 in the hydrided powders depending on composition and hydriding *** best results point to an optimum ni dispersion,which in turn depends on ni content and milling time.

关键词： Hydrogen storage Magnesium niquel Alloy Characterization

Deciphering deformation mechanisms of hierarchical dual-phase CrConi coatings

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

journal of Materials Science & Technology 2020年第4期39卷 7-13页

作者： S.j.Tsianikas Y.Chen Z.Xie School of Mechanical Engineering The University of AdelaideAdelaideSA5005Australia Centre for Advanced Thin Film Materials and Device Faculty of Materials and EnergySouthwest UniversityChongqing400715China School of Engineering Edith Cowan UniversityWA6027Australia

Hierarchical Cr Co ni medium entropy alloy(MEA)thin films with a dual-phase face-centred cubic(FCC)and hexagonal closed-packed(HCP)nanostructure were prepared on M2 steel substrates by closed field unbalanced magnetron *** tests show an ultra-high hardness of 9.5 GPa,attributable to large amounts of innate planar defects(i.e.,growth twins and stacking faults)impeding dislocation motion in the coatings.A deep analysis of undeformed and post-mortem samples reveals grain refinement as the dominant deformation mechanism in FCC dominated regions,while phase transformation and shear banding played major roles in regions occupied by HCP *** grain refinement was facilitated by twin/matrix lamellae,with dislocations piling up and arranging into interconnecting grain *** shear banding was accelerated by innate planar defects in the HCP phase due to a lack of slip *** particular interest is the observation of HCP→FCC phase transformation,which was catalysed by deformation-induced grain reorientation with innate stacking faults acting as embryos to grow the FCC *** results of this work suggest that multiple deformation pathways could be activated in Cr Co ni coatings with assistance of growth defects,thereby imparting these technically important coatings appreciable ductility.

关键词： Medium entropy alloys Sputter deposition Grain refinement Shear banding Phase transformation

基于神经网络的复合材料层合板低速冲击损伤面积预测方法

在线全文

学校读者我要写书评

暂无评论

河南工学院学报 2024年第3期32卷 34-43页

作者：卓嘉永倪楷文陈清林彭苗娇集美大学轮机工程学院福建厦门361021 福建省船舶与海洋工程重点实验室福建厦门361021

目前,复合材料层合板在船舶领域得到广泛应用,但在其遭受低速冲击时,传统试验和有限元方法无法真实、有效地描绘实际损伤情况。为此,结合低速冲击实验结果和超声水浸扫描结果,建立了BPNN、CNN的等效冲击损伤预测模型,以快速预测复合材... 详细信息

目前,复合材料层合板在船舶领域得到广泛应用,但在其遭受低速冲击时,传统试验和有限元方法无法真实、有效地描绘实际损伤情况。为此,结合低速冲击实验结果和超声水浸扫描结果,建立了BPNN、CNN的等效冲击损伤预测模型,以快速预测复合材料层合板在冲击过程中的损伤情况。在使用试验样本数据模型进行训练后,其能够高效准确预测复合材料层合板损伤面积。该方法简单实用,可以推广使用。

关键词：复合材料低速冲击神经网络损伤面积

A NOVEL METHOD FOr EVALUATiNG PLANE STrESS DYNAMiC FrACTUrE TOUGHNESS OF 0Cr18ni10Ti STAiNLESS STEEL WELDED j.i.TS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 303-312页

作者： Z.j. Xu Y.L. Li School of Aeronautics Northwestern Polytechnical University Xi＇an 710072 China

A novel method was proposed for the evaluation of Mode i dynamic fracture toughness （DFT） under plane stress and small scale yielding conditions for welded j.i.ts of stainless steel （SS）, 0Cr18ni10Ti. in a hybrid experimental-numerical approach, the experiments were carried out on the Hopkinson pressure bar apparatus, and three dimensional （3D） transient numerical simulations were performed by a finite element （FE） computer program. Macroscopical plastic deformation was observed at the loading and supporting points, on the specimens, after the test, which could cause a large error if omitted in the numerical simulation. Therefore, elustic-viscoplustic analysis was performed on the specimen by adopting the johnson-Cook （j-C） model to describe the rate-dependent plastic flow behavior of the material. The material heterogeneity in the mismatched welded j.i.ts, induced by the difference in the base metal （BM） and the weld metal （WM） in yield stress, has also been taken into consideration by using the j-C models separately. Good accordance was obtained between the experimental and the computational results by the present approach. The relationship between plane stress DFT and loading rate was also obtained on the order of 108 MPa.m^1/2.s^-1.

关键词： 0Cr18ni10Ti Welded j.i.t High strain rate Dynamic fracture Plane stress

Optimizing the oxide support composition in Pr-doped CeO_(2) towards highly active and selective ni-based CO_(2) methanation catalysts

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2022年第8期31卷 547-561,I0015页

作者： Anastasios i.Tsiotsias nikolaos D.Charisiou Ayesha AlKhoori Safa Gaber Vlad Stolojan Victor Sebastian Bart van der Linden Atul Bansode Steven j.Hinder Mark A.Baker Kyriaki Polychronopoulou Maria A.Goula Laboratory of Alternative Fuels and Environmental Catalysis(LAFEC) Department of Chemical EngineeringUniversity of Western MacedoniaGR-50100Greece Department of Mechanical Engineering Khalifa University of Science and TechnologyAbu DhabiP.O.Box 127788United Arab Emirates Center for Catalysis and Separations Khalifa University of Science and TechnologyAbu DhabiP.O.Box 127788United Arab Emirates Advanced Technology institute Department of Electrical and Electronic EngineeringUniversity of SurreyGuildford GU24DLUK Department of Chemical Engineering and Environmental Technology Universidad de ZaragozaCampus Río Ebro-Edificio I+D50018 ZaragozaSpain instituto de Nanociencia y Materiales de Aragón(iNMA) Universidad de Zaragoza-CSICc/María de Luna 350018 ZaragozaSpain Networking research Center on Bioengineering Biomaterials and NanomedicineCIBERBBN28029 MadridSpain Department of Chemical Engineering Delft University of TechnologyVan der Massweg 92629 HZ DelftThe Netherlands The Surface Analysis Laboratory Faculty of Engineering and Physical SciencesUniversity of SurreyGuildford GU24DLUK

in this study,ni catalysts supported on Pr-doped Ce O_(2) are studied for the CO_(2) methanation reaction and the effect of Pr doping on the physicochemical properties and the catalytic performance is thoroughly *** is shown,that Pr^(3+)ions can substitute Ce^(4+)ones in the support lattice,thereby introducing a high population of oxygen vacancies,which act as active sites for CO_(2) *** doping can also act to reduce the crystallite size of metallic ni,thus promoting the active metal *** performance evaluation evidences the promoting effect of low Pr loadings(5 at%and 10 at%)towards a higher catalytic activity and lower CO_(2) activation *** the other hand,higher Pr contents negate the positive effects on the catalytic activity by decreasing the oxygen vacancy population,thereby creating a volcano-type trend towards an optimum amount of aliovalent substitution.

关键词： Power-to-gas CO_(2)methanation ni-based catalyst Pr-doped CeO_(2) Oxygen vacancy Catalytic activity Activation energy