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Surface Characterisation of Silicon Based MEMS

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Chemical Research in Chinese Universities 2004年第4期20卷 407-410页

作者： LI j. CUI Z M. A. Baker The Surface Analysis Laboratory School of Engineering University of SurreyRutherford Appleton LaboratoryThe Surface Analysis Laboratory School of Engineering University of Surrey Guildford GU2 7XH UKChilton Didcot UKGuildford GU2 7XH UK

Polysilicon Microelectromechanical systems(MEMS) are the subject of intensive researches. Surface chemistry and topography of a MEMS test structure fabricated at Sandia National Laboratory, USA, were studied by means of scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AfM). XPS C_ 1sand Si_ 2pspectra from the polysilicon components, silicon nitride substrate and a reference silicon wafer were compared. The results confirm the presence of a self-assembled monolayer(SAM) on the MEMS surface. An island-like morphology was found on both polysilicon and silicon nitride surfaces of the MEMS. The islands take the form of caps, being up to 0.5 μm in diameter and 20 nm in height. It is concluded that the co-existence of columnar growth and equiaxed growth during the low pressure chemical vapor deposition(LPCVD) of these layers leads to the observed morphology and the islands are caps to the columnar structures.

关键词： Microelectromechanical systems XPS Atomic force microscopy

Reversible phosphorylation of the 26S proteasome

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Protein & Cell 2017年第4期8卷 255-272页

作者： Xing Guo Xiuliang Huang Mark j. Chen The Life Sciences Institute of Zhej.ang University Hangzhou 310058 China Ministry of Education Key Laboratory of Protein Science School of Life Sciences Tsinghua University Beijinq 100084 China Department of Bioinformatics and Computational Biology Genentech Inc. South San Francisco CA 94080 USA

The 26S proteasome at the center of the ubiquitin- proteasome system （UPS） is essential for virtually all cellular processes of eukaryotes. A common miscon- ception about the proteasome is that, once made, it remains as a static and uniform complex with sponta- neous and constitutive activity for protein degradation. Recent discoveries have provided compelling evidence to support the exact opposite insomuch as the 26S proteasome undergoes dynamic and reversible phos- phorylation under a variety of physiopathological con- ditions. In this review, we summarize the history and current understanding of proteasome phosphorylation, and advocate the idea of targeting proteasome kinases/ phosphatases as a new strategy for clinical interven- tions of several human diseases.

关键词： proteasome phosphorylation kinase,phosphatase protein degradation

Interannual and Decadal Variability of Landfalling Tropical Cyclones in the Southeast Coastal States of the United States

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Advances in Atmospheric Sciences 2002年第4期19卷 677-686页

作者： Li'an Xie Leonard j. Pietrafesa Kej.an Wu Department of Marine Earth and Atmospheric Sciences North Carolina Slate University Box 8208 27695-8208 Raleigh North Carolina USA Present address: Institute of Physical Oceanography The Ocean University of Qingdao 266003 Qingdao

The interannual variability of the Atlantic tropical cyclone (TC) frequency is well known. Separately, recent studies have also suggested that a much longer, multidecadal (40-60 year) trend might be emerging from the recent increase in Atlantic TC activity. However, the overall structure of the intrinsic frequencies (or temporal modes) of Atlantic TC activity is not yet known. The focus of this study is to systematically an-alyze the intrinsic frequencies of Atlantic TC activity using hurricane and tropical storm landfall data collec-ted along the southeast coast(SEC) of the United States, Based on an Empirical Mode Decomposition (EMD) analysis of the frequency of landfall TCs along the SEC from 1887-1999, we have found that Atlantic TC activity has four primary, temporal modes. The interannual and multidecadal modes reported in the published literature are two such modes. After identifying all primary modes, the relative importance of each mode and its physical cause can be analyzed. for example, the most energetic mode is the interannual mode (2-7 year period). This mode is known to be associated with the 2-7 year El Nino/ La Ni na cycle. The average number of annual landfalling TCs along (he SEC decreased by 24% during El Nino years, but did not show significant increase during weak and moderate La Nina years. However, intense La Nina years were generally associated with more than average landfalling TCs along the SEC. The effects of El Nino and La Nina also became more significant when only hurricanes were considered. The significance of the effects of El Nino and La Nina on landfalling TCs and hurricanes in different US southeast coastal states showed significant differences.

关键词： tropical cyclone empirical mode decomposition El Nino decadal variability

Zener Nodel Description of ferromagnetism in Zinc-Blende Magnetic Semiconductors

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Zener Nodel Description of Ferromagnetism in Zinc-Blende Mag...

Detection of Railway Ballast Damage by Vibration Measurement

CCAST“激光冷却：玻色—爱因斯坦凝聚和原子激射器”研讨会

作者： T.Dietl H.Ohno f.Matsukura j.Cibert D.ferrand Research institute of Electrical Communication Tohoku UniversityKatahira 2-1-1 Sendai 980-8577.JapanInstitute of Physics and College of SciencePolish Academy of Sciencesat.Lotnikow 32/46PL02668 Warsaw.Poland.To wnom correspondence should be addressed. Research institute of Electrical Communication To-hoku University Katahira 2-1-1 Sendai 980-8577.Japan.To wnom cortespondence should be addressed. Research Institute of Electrical Communication Tohoku Universitykatahira 2-1-1 Sendai 980-8577.Japan. Laboratoire de Spectromarie Physique.Universite joseph fourier Grenoble 1-CNRS IUMR 55881 f-38402 Saint Martin d’Hees Cedex france.

ferromagnetism in manganese compound semiconductors not only opens pros-pects for tailoring magnetic and spin-related phenomena in semiconductorswith a precision specific to ill-V compounds but also addresses a question aboutthe origin of the magnetic interactions that lead to a Curie temperature (T)as high as 110 K for a manganese concentration of just 5%. Zener’s model offerromagnetism. originatty proposed for transition metals in 1950. can exptainT of GaMnAs and that of its Ⅱ-Ⅵ counterpart ZnMnTe and is used topredict materials with T exceeding room *** important steptoward semiconductor electronics that use both charge and spin.

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Detection of Railway Ballast Damage by Vibration Measurement

Characterization of the Tar Produced during Pyrolysis of Common Reed: A Comparative Study between On-Line and Off-Line Measuring Method Approaches

The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth forum on Mechanics 2012、The 8th Shanghai-Hong Kong forum on Mechanics and Its Application 2012

作者： Q.Hu H.f.Lam j.H.Yang H.Y.Peng Department of Civil and Architectural Engineering City University of Hong Kong

With the advent of high speed and high capacity railway systems,damage of the railway ballast(i.e.,the crash of ballast into smaller sizes) has become more and more *** main function of ballast is to hold the sleepers and rails in *** ballast damage will lead to rail buckling and so as to increase the chance of ***,the damage detection of the railway ballast plays an important role in railway *** railway companies mainly rely on visual inspection and destructive core test for ballast damage ***,visual inspection is only effective to detect ballast damage on the surface,the ballast damage under sleepers is impossible to be detected in this way,thus a practical railway ballast damage detection method is in *** the ballast under the sleeper is damaged,the stiffness of the ballast in supporting the sleeper will be *** change in stiffness will alter the vibration characteristics of the concrete *** the literature,some researchers propose to use in-situ vibration measurement(Lam et al.2010;Lam and Wong 2011) to estimate the change in ballast stiffness by following a model-based *** paper reports the results of the numerical and experimental case studies of the research work in Lam and Wong(2011).In the proposed method,the rail-sleeper-ballast system is modeled as a Timoshenko beam on elastic *** ballast stiffness is represented by the stiffness of the elastic *** reduction in ballast stiffness can then be estimated by model updating of the rail-sleeper -ballast system using the measured vibration data of the in-situ sleeper. To test the proposed method,a full-scale ballasted track was built in an indoor test panel.A series of well-designed impact hammer tests was carried out on the intact in-situ *** updating of the undamaged rail-sleeper-ballast system was employed to identify a representative model to represent the real *** this comput

关键词： Detection of Railway Ballast Damage by Vibration Measurement

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Characterization of the Tar Produced during Pyrolysis of Com...

The 20th European Biomass Conference and Exhibition

作者： Patuzzi,f. Roveda,D. Mimmo,T. Karl,j. Baratieri,M.

In this paper a practical test of an innovative on-line tar measuring system has been carried out using the reference standard for tar sampling（UNI CEN/TS 15439） and off-line analysis approach. Samples of common reed-collected in Inner Mongolia（China）-have been characterized by means of physical-chemical and thermal analysis. Several experimental tests have been performed in a bench scale pyrolysis apparatus（free University of Bolzano, Italy） setting different process temperature（300-700°C） and a heating rate of 50°C/min. In each test the condensable fraction（i.e., tar） has been collected and analysed. These analyses have been supplemented with an innovative on-line tar measuring methodology, developed at the Graz University of Technology（Austria）. The system consists of a lab scale fluidised bed gasifier coupled with an optical measurement cell. In the measurement cell a UV light stream is produced by means of LEDs having different wavelengths（265nm, 285 nm, 300 nm and 365nm）. The spectrum of absorbed light from the tar in the gaseous products can be detected through a photodiode, being proportional to their concentration. The integration between different analytical approaches on tar characterization has been useful to assess their capability and their potential application.

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组织与管理

组织与管理

Symmetry and Transitive Properties of Monohedral f-triangulations of the Riemannian Sphere

作者： f.E.·卡斯特(f.E. Kast) j.E.·罗森茨韦克(j.E. Rosenzwig)

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Acta Mathematica Sinica,English Series 2009年第10期25卷 1609-1616页

作者： Ana M.BREDA j.M.SIGARRETA Department of Mathematics University of Aveiro facultad de Matematicas Universidad Autonoma de Guerrero

Here we give the complete description of the symmetry group and transitive properties of the set of all of monohedral triangulations of the Riemannian sphere by f-tilings. We shall also show that each monohedral f-tiling of the Riemannian sphere can be seen, up to a spherical isometry, as the singular set of a spherical isometric folding.

关键词： isometric folding monohedral tiling graphs combinatoric

Myocardial contraction maps using tissue Doppler acceleration imaging

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Chinese Medical journal 2000年第8期113卷 91-96页

作者：尹立雪 Marek Belohlavek Douglas L.Packer james f.Greenleaf james B.Seward Div. Cardiovasc. Dis. and Int. Med. Mayo Clinic Mayo Foundation Rochester MN United States Provincial Hospital Chengdu 610071 China Dept. of Physiology and Biophysics Mayo Clinic Mayo Foundation Rochester MN United States

ObjectiveTo evaluate the tissue Doppler acceleration imaging(TDAI)data which can be used to determine the intramural site of origin of myocardial contraction in response to electrical stimulation.MethodsSix open-chest pigs with left ventricle(LV)pacing were evaluated with TDAI. An epicardial surface scanning method was used to collect short-axis views of the left ventricle. The electrode was implanted from the epicardium through the anterior free wall to an intramural position.ResultsDuring pacing, the intramural onset of myocardial acceleration occurred within 33 ms after electrical stimulation and always surrounded the embedded subendocardial end of the pacing needle. The observed short-axis diameter of the area of initial myocardial acceleration ranged from 2.9 mm to 5.0 mm(4.2±0.9 mm, n = 6). The onset of myocardial acceleration allowed appreciation of the initial intramural myocardial contraction. The spatial size and acceleration magnitude of the initial myocardial acceleration distribution were irregular.ConclusionTwo-dimensional myocardial acceleration mapping can show the intramural site of origin of myocardial contraction in response to paced electrical stimulation. The location of myocardial acceleration conformed to the site of initial electrical stimulation. The delay to the earliest regional myocardial contraction, 33 ms after paced electrical stimulation, was related to the frame rate of image acquisition. Chin Med j 2000; 113(8): 763-768

关键词： electrical pacing myocardial contraction tissue Doppler acceleration imaging