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边界润滑条件下机油污染物对摩擦学性能的影响

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润滑与密封 2017年第2期42卷 1-5页

作者： mOh.m.D Kamal Ahmed Ali FAWZY m.h.Ezzat 侯献军陈必成蔡清平现代汽车零部件技术湖北省重点实验室(武汉理工大学) 湖北武汉430070 米尼亚大学工程学院米尼亚61111 汽车零部件技术湖北省协同创新中心湖北武汉430070

选用Fe、Cu、Al、Pb、SiO_2固体颗粒作为机油污染物,在模拟的发动机缸套-活塞环往复运动实验台上,研究边界润滑条件下固体污染物含量和尺寸对机油摩擦学性能的影响。实验结果表明:机油中的固体颗粒物导致摩擦因数和摩擦功损失增加,同时... 详细信息

选用Fe、Cu、Al、Pb、SiO_2固体颗粒作为机油污染物,在模拟的发动机缸套-活塞环往复运动实验台上,研究边界润滑条件下固体污染物含量和尺寸对机油摩擦学性能的影响。实验结果表明:机油中的固体颗粒物导致摩擦因数和摩擦功损失增加,同时增加摩擦副接触面的表面粗糙度;摩擦因数、摩擦功损失、磨损量均随污染物含量、颗粒物尺寸的增加而增加,其中铁粒子污染物影响最大,铜次之,铅的影响最小;固体颗粒物会降低发动机性能,增加燃油消耗,为降低固体颗粒物对机油的影响,必须提高机油过滤精度。

关键词：固体污染物机油边界润滑摩擦磨损

Achieving superior strength-ductility synergy in a heterostructured magnesium alloy via low-temperature extrusion and low-temperature annealing

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Journal of materials Science & Technology 2023年第32期163卷 32-44页

作者： h.Wang D.T.Zhang C.Qiu W.W.Zhang D.L.Chen Guangdong Key Laboratory for Advanced metallic materials Processing and Forming National Engineering Research Center of Near-net-shape Forming for Metallic MaterialsSouth China University of TechnologyGuangzhou 510640China Department of mechanical and Industrial Engineering Toronto Metropolitan University(formerly Ryerson University)350 Victoria StreetTorontoON M5B 2K3Canada

A low-alloyed mg-1.2Zn-0.1Ca(wt.%)alloy was fabricated via low-temperature extrusion and annealing at 250℃for different times(10,30,and 90 min)to attain heterostructures with different fine-grained fractions,focusing on the effect of heterostructure on the mechanical *** dynamic recrystallization(RX)occurred during extrusion at 150℃,and a lamellar structure consisting of fine RX grains and coarse unRX grains was *** subsequent annealing promoted static RX in the as-extruded alloy,leading to an increased fine-grained fraction from 67%to 95%.meanwhile,the co-segregation of Zn and Ca atoms impeded the migration of grain boundaries,thus achieving a fine grain size of 0.8–1.6μ*** sample annealed for 10 min with a fine-grained fraction of 73%and an average RX grain size of 0.9μm exhibited a superior combination of high yield strength(305 mPa)and good ductility(20%).In comparison,an excellent elongation of 30%was achieved in the alloy with a nearly fully-RXed microstructure and an average grain size of 1.6μm after 90 min annealing,despite a lower yield strength of 228 *** unRX grains,the hard orientation with(01–10)parallel to the extrusion direction and high-density dislocations made it more difficult to deform compared with the RX grains,thus producing hetero-deformation induced(hDI)*** fine grains and high-density dislocations,hDI strengthening is the key to achieving the superior mechanical properties of the low-alloyed mg alloy.

关键词： Low-alloyed magnesium alloy Low-temperature extrusion Annealing heterostructure mechanical properties

micromagnetics and Signal Analysis of Shielded Spin-Valve multilayer

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Chinese Physics Letters 1996年第6期13卷 469-472页

作者： ZhANG huai-wu YANG Shi-qing LIU Ying-li WANG hao-cai h.J.Kim Institute of materials and Information Engineering University of Electronic Science and TechnologyChengdu 610054 magnetic Alloy Laboratory Metals DivisionKorea Institute of Science and TechnologyP.O.Box 131ChenogryangSeoulKorea

In order to linearize a spin-valve giant magnetoresistance head,the exchanges layer sputtered at fringe area or a permanent magnet layer longitudinal biasing for domain stabilization based on a physical calculated model may be *** correlations between the head performance characteristic and head geometric parameters have been simulated by putting the head on a suitable front-end electric *** simulative results show that the optimal sensing current is from 10 to 40mA and the linear geometric parameteres for gap width are at the range of G_(1)+G_(2)≤0.5μm.

关键词： stabilization permanent Signal

Stability analysis of slopes with planar failure using variational calculus and numerical methods

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Frontiers of Structural and Civil Engineering 2020年第5期14卷 1262-1273页

作者： Norly BELANDRIA RobertoÚCAR Francisco m.LEON Ferri hASSANI Geological Engineering School University of Los AndesMérida 5101Venezuela mechanical Engineering School University of Los AndesMérida 5101Venezuela Department of mining and material Engineering McGill UniversityMontrealQC H3A 0E9Canada

This study investigates the technique of variational calculus applied to estimate the slope stability considering the mechanism of planar *** critical plane failure surface should be determined because it theoretically indicates the most unfavorable plane to be considered when stabilizing a slope to rectify the instability generated by several statistically possible *** generates integrals that can be solved by numerical methods,such as the Newton Cotes and the finite differences ***,a system of nonlinear equations is obtained and *** surface of the critical planar failure is determined by applying the condition of transversality in mobile boundaries,for which various examples are *** number of slices is varied in one of the examples,while the surface of the critical planar failure is determined in the *** are compared using analytical methods through axis *** the results obtained by considering normal stress,safety factors,and critical planar failure are nearly the same;however,in this research,a study is carried out for“n”number of slices using programming ***-routines are important because they can be applied in slopes with different geometry,surcharge,interstitial pressure,and pseudo-static load.

关键词： slopes stability planar failure variational calculus numerical methods

Soft coral Cespitularia stolonifera:New cytotoxic ceramides and gastroprotective activity

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Chinese Journal of Natural medicines 2017年第2期15卷 105-114页

作者： Abdelsamed I.Elsh.m. Walaa A.El-Kashak heba m.I.Abdallah Abdelrazik h.Farrag mahmoud I.Nassar Natural Compounds Ch.m.stry Department National Research CentreGiza 12622Egypt Pharmacology Department National Research CentreGiza 12622Egypt Pathology Department National Research Centre Giza 12622Egypt

In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol(1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol(2), 24-methylcholesta-5, 24(28)-diene-3β-acetate(3), 4-methyl-24-methylcholesta- 22-ene-3-ol(4), and cholesterol, was isolated and characterized from Ch2Cl2/me Oh extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate(1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NmR, hRESI-mS, and GC-mS, in addition of ch.m.cal methods.(-)-Alloaromadendren, ledane,(1)-alloaromadendren oxide, isoaromadendrene epoxide and(-)-caryophellen oxide were identified from the n-hexane fraction using GC-mS. The extract and the two ceramides(1) and(1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids(2) and(3) exhibited significant cytotoxic activity against breast cancer mCF-7 cells. The Ch_2Cl_2/meOh extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histoch.m.cal, and bioch.m.cal examinations.

关键词： Cespitularia stolonifera Ceramide Steroids Anticancer leading constituents Antiulcer activity

Characterization and mode of action analysis of black soldier fly(hermetia illucens)larva-derived h.m.cytes

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Insect Science 2022年第4期29卷 1071-1095页

作者： Yvette m.von Bredow Ariane müller Philipp F.Popp Denis Iliasov Christoph-Rüdiger von Bredow Justus-Liebig-Universität Gießen Institut für Allgemeine Zoologie und EntwicklungsbiologieZelluläre Erkennungs-und AbwehrprozesseGießenGermany Technische Universität Dresden Fakultät BiologieInstitut für ZoologieDresdenGermany Technische Universität Dresden Fakultät BiologieInstitut für MikrobiologieDresdenGermany Present address:Philipp F.Popp Institute for Biology-Bacterial PhysiologyHumboldt-Universität zu BerlinBerlinGermany

With the growing importance of the black soldier fly(hermetia illucens)for both sustainable food production and waste management as well as for science,a great demand of understanding its immune system ***,we present the first description of the circulating larval h.m.cytes with special emphasis on uptake of microorganisms and distinguishing h.m.cyte *** histological,zymographic,and cytometric methods and with a set of h.m.cyte binding lectins and antibodies,the h.m.cytes of *** are identified as plasmatocytes,crystal cells,and putative *** h.m.cyte counts(ThC)are determined,and methods for ThC determination are *** 1100 h.m.cytes per microliter h.m.lymph are present in naive animals,while h.m.cyte density decreases dramatically shortly after wounding,indicating a role of h.m.cytes in response to wounding(and immune response in general).The determination of the relative abundance of each h.m.cyte type(differential h.m.cyte count,DhC)revealed that plasmatocytes are highly abundant,whereas proh.m.cytes and crystal cells make up only a small percentage of the circulating *** are not only the most abundant but also the professional phagocytes in *** rapidly engulf and take up bacteria both in vivo and in vitro,indicating a very potent cellular defense against invading *** bioparticles such as yeasts are also removed from circulation by phagocytosis,but slower than *** is the first analysis of the potent cellular immune response in the black soldier fly,and a first toolbox that helps to identify h.m.cyte(types)is presented.

关键词： black soldier fly(hermetia ilucens) cellular immunity crystal cell h.m.cyte types immunity of economically imporant insects microbe phagoeytosis plasmatocyte

Formation of Re-containing Carbides in a Second Generation Directionally Solidified Ni Base Superalloy

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Journal of materials Science & Technology 2009年第3期25卷 361-364页

作者： T. Zhao D. Wang J. Zhang G. Chen L.h. Lou School of materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China Institute of metal Research Chinese Academy of Sciences Shenyang 110016 China

The precipitates at grain boundary in a directionally solidified Ni base superalloy after heat treatment, aging at 975℃, and creep rupture test have been characterized. Besides the primary mC carbides and fine particles of u phase, the Re-containing m23C6 was observed. The precipitation kinetics revealed that the formation of m23C6 was associated with the dissolution of u phase and mC carbides. TEm image shows that the continuous precipitation of m23C6 particles effectively hinders the dislocation movement and strengthens the grain boundaries. The high strength of the alloy suggests that m23C6 carbides are beneficial to the properties although Re as an important matrix strengthening element was consumed.

关键词： Ni-base Superalloys Directional solidification Rhenium Carbide

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一种预防噪声导致失聪的新方法(英文)

解放军医学杂志 2009年第5期34卷 519-522页

作者： h.麦尔 T.列纳 m.缇雪 J.m.米勒 Bundeswehrkrankenhaus Ulm Ulm Germany Department of Otolaryngology Medical University of HannoverHannover Germany Kresge hearing Research Institute University of Michigan Ann Arbor MI USA and Center for Hearing and Communication Kdrolinska Institute Stockholm Sweden

对一个国家来说,噪声导致的失聪是一种巨大的社会和经济损失,是以前未曾遇到过的医疗卫生问题,现在这个问题有了一种解决办法。美国农业部(FDA)近年来没有批准任何预防噪声导致失聪的新产品。在美国,这类产品(包括耳塞和耳罩)的市场价... 详细信息

对一个国家来说,噪声导致的失聪是一种巨大的社会和经济损失,是以前未曾遇到过的医疗卫生问题,现在这个问题有了一种解决办法。美国农业部(FDA)近年来没有批准任何预防噪声导致失聪的新产品。在美国,这类产品(包括耳塞和耳罩)的市场价值大约为2.43亿美元,其中约75%来自耳塞的销售。对听力的物理防护可以降低声压水平,但若噪声过强,这种物理防护并不能完全保证听力不受损害。而且,这类"屏蔽"方法也会损害需要通过听、说进行交流来保证的个人安全性。近十年来我们对应激、病理和年龄因素在决定细胞生存和死亡的分子和生化机制方面有了明显深入的了解和认识。我们可以确定导致细胞死亡的凋亡或坏死途径,以及对这些途径起调节作用的外部环境或内源性遗传启动因子、基因及转导因子。用这些新知识,我们开始设计新的干预方法来减轻或防止细胞死亡,使我们第一次能够预防或治疗以前不能预防或治疗的疾患,失聪即是其中一种。

关键词：噪声听力损伤抗氧化剂自由基血管扩张剂

热消融治疗肝内胆管癌:一项系统性回顾和meta分析

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国际医学放射学杂志 2022年第2期 246-247页

作者： G.h.Kim P.h.Kim J.h.Kim P.N.Kim h.J.Won Y.m.Shin 汤双燕

摘要目的总结热消融治疗肝内胆管癌（ICC）的疗效和安全性。方法检索mEDLINE、EmBASE、Cochran Library和Web of Science数据库，查找关于通过热消融治疗ICC病人疗

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