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The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage

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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND robert l.jackson German MIllS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

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多尺度粗糙度对接触面真实接触面积的影响

润滑与密封 2015年第6期40卷 76-80页

作者：张晓寒 robert l.jackson 孟文俊太原科技大学机械工程学院山西太原030024 Mechanical Engineering Auburn Universityauburnusa36849

当两个粗糙面在力的作用下相互接触时,只有表面上的微凸体相互接触。这些微凸体的接触影响着接触面的摩擦、磨损并且决定着两接触面之间的导电性和热传递功能。这些微凸体存在于各个不同的尺度下,并且形状也不相同。运用堆叠式多尺度接... 详细信息

当两个粗糙面在力的作用下相互接触时,只有表面上的微凸体相互接触。这些微凸体的接触影响着接触面的摩擦、磨损并且决定着两接触面之间的导电性和热传递功能。这些微凸体存在于各个不同的尺度下,并且形状也不相同。运用堆叠式多尺度接触模型对典型的加工表面进行分析,研究多尺度粗糙度对接触面真实接触面积的影响。结果表明,在塑性接触和弹塑性接触情况下,接触表面的多尺度粗糙度对于真实的接触面积和接触力均都有着很大的影响,不同表面之间的接触面积和平均接触压力以一个数量级的大小变化。研究结果表明某些加工工艺得到的表面或许更适合于作为设备中相互接触的表面。

关键词：粗糙表面接触表面凸起多尺度接触模型

Human resource management robert l. Mathis, John H. jackson. 8th ed.

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The Schlager mouse as a model of altered retinal phenotype

1997年

作者： robert l. Mathis John H. jackson.

来源：畅想之星图书光盘版（南... 评论

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Neural Regeneration Research 2020年第3期15卷 512-518页

作者： lakshini Y.Herat Aaron l.Magno Márcio G.Kiuchi Kristy l.jackson Revathy Carnagarin Geoffrey A.Head Markus P.Schlaich Vance B.Matthews Dobney Hypertension Centre School of Biomedical Science-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Research Centre Royal Perth HospitalPerthAustralia Dobney Hypertension Centre School of Medicine-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Neuropharmacology laboratory Baker Heart and Diabetes InstituteMelbourneAustralia Department of Cardiology and Department of Nephrology Royal Perth HospitalPerthAustralia

Hypertension is a risk factor for a large number of vision-threatening eye *** this study,we investigated for the first time the retinal neural structure of the hypertensive BPH/2J mouse(Schlager mouse)and compared it to its control counterpart,the normotensive BPN/3J *** BPH/2J mouse is a selectively inbred mouse strain that develops chronic hypertension due to elevated sympathetic nervous system *** compared to the BPN/3J strain,the hypertensive BPH/2J mice showed a complete loss of outer layers of the neural retina at 21 weeks of age,which was indicative of a severe vision-threatening disease potentially caused by *** elucidate whether the retinal neural phenotype in the BPH/2J strain was attributed to increased BP,we investigated the neural retina of both BPN/3J and BPH/2J mice at 4 weeks of *** preliminary results showed for the first time that the BPH/2J strain develops severe retinal neural damage at a young *** findings suggest that the retinal phenotype in the BPH/2J mouse is possibly due to elevated blood pressure and may be contributed by an early onset spontaneous mutation which is yet to be identified or a congenital defect occurring in this *** characterization of the BPH/2J mouse strain is likely to i)elucidate gene defects underlying retinal disease;ii)understand mechanisms leading to neural retinal disease and iii)permit testing of molecules for translational research to interfere with the progression of retinal *** animal experiments were performed with the approval of the Royal Perth Hospital Animal Ethics Committee(R535/17-18)on June 1,2017.

关键词： blood pressure eye hypertension mice neural regeneration retina Schlager mouse sympathetic nervous system

Himalayas as a global hot spot of springtime stratospheric intrusions:Insight from isotopic signatures in sulfate aerosols

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Research in Cold and Arid Regions 2024年第1期16卷 5-13页

作者： Kun Wang ShiChang Kang Mang lin PengFei Chen Chaoliu li XiuFeng Yin Shohei Hattori Teresa l.jackson JunHua Yang YiXi liu Naohiro Yoshida Mark HThiemens State Key laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)LanzhouGansu 730000China State Key laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryCASGuangzhouGuangdong 510640China University of Chinese Academy of Sciences Beijing 100049China International Center for Isotope Effects Research(ICIER) School of Earth Sciences and EngineeringNanjing UniversityNanjingJiangsu 210023China Frontiers Science Center for Critical Earth Material Cycling State Key Laboratory for Mineral Deposits ResearchSchool of Earth Sciences and EngineeringNanjing UniversityNanjingJiangsu 210023China Department of Chemical Science and Engineering School of Materials and Chemical TechnologyTokyo Institute of Technology4259 Nagatsuta-choMidori-kuYokohamaKanagawa 226-8502Japan Department of Chemistry and Biochemistry University of California San DiegoLa JollaCA 92093-0021USA Earth-life Science Institute Tokyo Institute of TechnologyMeguro-kuTokyo 152-8551Japan National Institute of Information and Communications Technology KoganeiTokyo 184-8795Japan

Downward transport of stratospheric air into the troposphere(identified as stratospheric intrusions)could potentially modify the radiation budget and chemical of the Earth's surface *** the highest and largest plateau on earth,the Tibetan Plateau including the Himalayas couples to global climate,and has attracted widespread attention due to rapid warming and cryospheric *** studies recognized strong stratospheric intrusions in the Himalayas but are poorly understood due to limited direct evidences and the complexity of the meteorological dynamics of the third ***^(35)S is a radioactive isotope predominately produced in the lower stratosphere and has been demonstrated as a sensitive chemical tracer to detect stratospherically sourced air mass in the planetary boundary ***,we report 6-month(April–September 2018)observation of^(35)S in atmospheric sulfate aerosols(^(35)SO_(4)^(2-))collected from a remote site in the Himalayas to reveal the stratospheric intrusion phenomenon as well as its potential impacts in this *** the sampling campaign,the^(35)SO_(4)^(2-)concentrations show an average of 1,070±980 atoms/m^(3).In springtime,the average is 1,620±730 atoms/m^(3),significantly higher than the global existing data measured so *** significant enrichments of^(35)SO_(4)^(2-)measured in this study verified the hypothesis that the Himalayas is a global hot spot of stratospheric intrusions,especially during the springtime as a consequence of its unique geology and atmospheric *** combined with the ancillary evidences,e.g.,oxygen-17 anomaly in sulfate and modeling results,we found that the stratospheric intrusions have a profound impact on the surface ozone concentrations over the study region,and potentially have the ability to constrain how the mechanisms of sulfate oxidation are affected by a change in plateau atmospheric properties and *** study provides new observational constraints on stra

关键词： Himalayas Stratospheric intrusions Cosmogenic^(35)SO_(4)^(2-) Ozone Atmospheric oxidation

How spiders practice aggressive and Batesian mimicry

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Current Zoology 2012年第4期58卷 620-629页

作者： Ximena J. NElSON robert R. jackson School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch New Zealand International Centre of Insect Physiology and Ecology Thomas Odhiambo Campus EO. Box 30 Mbita Point Kenya

To understand communication, the interests of the sender and the receiver/s of signals should be considered sepa-rately. When our goal is to understand the adaptive significance of specific responses to specific signals by the receiver, questions about signal information are useful. However, when our goal is to understand the adaptive significance to the sender of generating a signal, it may be better to envisage the receiver＇s response to signals as part of the sender＇s extended phenotype. By making signals, a sender interfaces with the receiver＇s model of the world and indirectly manipulates its behaviour. This is especially clear in cases of mimicry, where animals use deceptive signals that indirectly manipulate the behaviour of receivers. Many animals adopt Batesian mimicry to deceive their predators, or aggressive mimicry to deceive their prey. We review examples from the lite-rature on spiders to illustrate how these phenomena, traditionally thought of as distinct, can become entangled in a web of lies .

关键词： Mimicry Communication Spider Deception Signal Search image

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供热设备火灾的调查

消防技术与产品信息 2000年第5期13卷 49-52页

作者： Arthur l.jackson 韩蕾开封市消防支队防火处

Mitigation of spectral leakage for single carrier, block-processing cognitive radio receivers

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Digital Communications and Networks 2018年第2期4卷 106-110页

作者： Adam C. Polak Mark Wagner Marco F. Duarte robert W. jackson Dennis l. Goeckel Electrical and Computer Engineering Department University of Massachusetts Amherst United States

Cognitive Radio （CR） is a multiuser, wireless communication concept that allows for a dynamic and adaptive assignment of spectral resources. The coexistence of multiple users, often transmitting at significantly different power levels, makes CR receivers vulnerable to spectral leakage caused by components＇ nonlinearities and timetruncation of the processed signal records. In this work we propose a method for mitigating the latter with an adaptive choice of the length of the processing block size. With simulations we show that a significant leakage reduction that leads to receiver dynamic range improvement of around 10 dB can be achieved with the proposed method.

关键词： Spectral leakage Dynamic range Single carrier block transmission Interference White space Cognitive radio

SO(n)-Invariant Special lagrangian Submanifolds of C^(n+1) with Fixed loci

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Chinese Annals of Mathematics,Series B 2006年第1期27卷 95-112页

作者： robert l. BRYANT Dedicated to the memory of Shiing-Shen Chern

let SO（n） act in the standard way on C^n and extend this action in the usual way to C^n＋l = C＋ C^n. It is shown that a nonsingular special lagrangian submanifold l→∪ C^n＋l that is invariant under this SO（n）-action intersects the fixed C→∪ C^n＋1 in a nonsingular real-analytic arc A （which may be empty）. If n 〉 2, then A has no compact component. Conversely, an embedded, noncompact nonsingular real-analytic arc A→∪ C lies in an embedded nonsingular special lagrangian submanifold that is SO（n）-invariant. The same existence result holds for compact A if n =2. nonsingular SO（n）-invariant special lagrangian nonsingular SO（n）-invariant special lagrangian extensions in some open neighborhood of A. If A is connected, there exist n distinct extensions of A such that any embedded extension of A agrees with one of these n The method employed is an analysis of a singular nonlinear PDE and ultimately calls on the work of Gerard and Tahara to prove the existence of the extension.

关键词： Calibrations Special lagrangian submanifolds