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  • 2005-2009  (21)
  • 1995-1999  (16)
  • 1970-1974
  • 2008  (21)
  • 1998  (16)
  • 1
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Tomographic imaging of the ionosphere is a recently developed technique that uses integrated measurements and computer reconstructions to determine electron densities. The integral of electron density along vertical or oblique paths is obtained with radio transmissions from low-earth-orbiting (LEO) satellite transmitters to a chain of receivers on the earth's surface. Similar measurements along horizontal paths can be made using transmissions from Global Position System (GPS) navigation satellites to GPS receivers on LEO spacecraft. Also, the intensities of extreme ultraviolet (EUV) emissions can be measured with orbiting spectrometers. These intensities are directly related to the integral of the oxygen ion and electron densities along the instrument line of sight. Two-dimensional maps of the ionospheric plasma are produced by analyzing the combined radio and EUV data using computerized ionospheric tomography (CIT). Difficulties associated with CIT arise from the nonuniqueness of the reconstructions, owing to limited angle measurements or nonoptimal receiver location. Improvements in both reconstruction algorithms and CIT measurement systems are being implemented to overcome these difficulties. New imaging systems being developed employ CIT for large area mapping of the plasma densities in the ionosphere. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 2328-2333 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: p-i-n photodiodes were fabricated on nitrogen ion implanted undoped ZnSe/n-type ZnSe epilayers grown on n+GaAs (100) substrates by molecular beam epitaxy. To obtain a quasi-uniform p layer doping profile, nitrogen ions at multiple energies and ion doses were implanted at room temperature. The activation of implanted species was carried out by an optimized post-annealing in a nitrogen ambient. Optical studies were performed on the implanted/annealed devices by photoluminescence spectroscopy at 10 K, which indicated donor–acceptor pairs at an energy of 2.7 eV and its phonon replicas with 30 meV intervals. The circular p-i-n diodes with a 1 mm diam contact area showed a device breakdown voltage to be linearly dependent on the thickness of the undoped ZnSe epilayer. For p-i-n diodes fabricated on an initial 0.5 μm thick undoped ZnSe layer, an ideality factor of 1.19 and a reverse bias breakdown voltage of 12 V was observed. A large photocurrent, good linearity with light intensity, and low dark current were observed. A photocurrent/dark current ratio 〉105 was obtained at an illumination intensity of 100 mW/cm2. These devices exhibited a responsivity of 0.025 A/W at a wavelength of 460 nm through the top 200 Å thick metal contacts.© 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A tertiary crystal growth method was used to fabricate thin gauged 3% Si–Fe sheets in order to reduce the thickness of the sheets without deteriorating soft magnetic properties. During the investigation, the magnetic properties of final annealed sheets were found to be directly related to the magnetic properties of final cold rolled sheets. X-ray and transmission electron microscopy were used to understand the above relation. It was found that the fraction of (110) grains at the surface of the final cold rolled sheets significantly affected the final magnetic properties of the final annealed sheets. On the basis of the above argument, the final magnetic properties of the thin gauged Si–Fe sheets can be predicted by the B10 values of the final cold rolled sheets. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 6614-6616 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: (Co1−xFex)Pt films were grown on a glass substrate by a rf sputtering and then annealed at 650–700 °C in a high vacuum. All the as-sputtered (Co1−xFex)Pt films deposited below 400 °C had a disordered structure and showed very low coercivities. With increasing the deposition temperature and Fe contents, the (111) texture was weakened in as-deposited (Co1−xFex)Pt ternary films. Vibrating sample magnetometer and x-ray diffraction data show that Co atoms in the L10 CoPt phase were substituted with Fe atoms. In-plane coercivities of these films decreased almost linearly with increasing Fe content which seemed to be due to the decrease of a crystalline anisotropy energy. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford BSL : Blackwell Science Ltd
    British journal of dermatology 139 (1998), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Fas, a cell surface receptor and member of the tumour necrosis factor receptor superfamily, induces apoptosis upon oligomerization by its ligand (Fas ligand: FasL). Detailed studies have revealed that Fas is broadly expressed in normal human tissues, but relatively little is known about the range of cell types capable of expressing FasL. The aim of this study was to determine the in vivo patterns of expression of Fas and FasL in human skin tissues. Immunohistochemistry was performed using paraffin-embedded samples of normal and neoplastic skin tissues. In normal skin, FasL was expressed in the epidermis, sebaceous glands, sweat glands and outer root sheath of the hair. In squamous cell carcinomas (SCC), all cases analysed expressed FasL at high levels, whereas 60% of basal cell carcinomas (BCC) were positive for FasL. Expression of Fas in normal skin was observed in the basal and spinous layers of the epidermis, the outer root sheath of the hair, and the sebaceous glands. Expression of Fas was observed in all the SCC tested and none of the BCC tested. Expression of FasL by normal cells and tumour cells in skin tissue, demonstrated for the first time in the present study, may provide an important clue to understanding skin physiology, and immune evasion of skin tumours.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 33-37 (Mar. 2008), p. 987-992 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Anodic alumina has exhibits a homogeneous morphology of parallel pores that can beeasily controlled between 10 and 400 nm. AAO(Anodic Aluminum Oxide) structure is thetransversely isotropic material due to the parallel pores. In this study, mechanical properties of theAAO structures are measured using the nano-indentation method. Nano-indentation technique is oneof the most effective methods to measure mechanical properties of nano-structures. Investigation ofmechanical properties, such as the indentation modulus and hardness of the AAO structure withvarying nano-pore sizes, was performed using the nano-indentation method. The results showed thatthe indentation modulus and hardness decreases monotically as the pore size increases
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 44-46 (June 2008), p. 581-586 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Manufacturing enterprises need to manage many inventory items. To effectively managethe inventory, a usual practice is to classify the inventory items into several groups and use differentmanagement strategies for the items in different groups. ABC classification has been widely used,and has evolved into various multi-criteria classification schemes. Recently, a few multi-criteriaABC classification approaches using variable weights appeared in the literature. This paper analyzestheir properties and proposes an improved approach. A numerical example is included to illustratethe appropriateness of the proposed approach
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 47-50 (June 2008), p. 1145-1148 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A good method for dispersing Multi-walled carbon nanotubes (MWNTs) in LDPE matrixby melt processing technique had been developed. The surface of MWNTs was modified by HNO3,then, treated with γ-aminopropyltriethoxy Silane. The surface-modified MWNTs homogeneousLDPE composites with 0-0.35 mass fraction MWNTs loading had been evaluated for electricalconductivity. The composites’ electrical conductivity (σDC) was improved for the good dispersion ofMWNTs in LDPE matrix. The values of σDC obeyed a percolation power law with MWNTsconcentration threshold 0.10 mass fraction. 10-2 s/cm conductivity for 0.15 mass fraction MWNTsloading indicated that the composites could be used as lightweight electrostatic shielding materials
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 58 (Oct. 2008), p. 103-108 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Thermal insulating latex paint for exterior wall was prepared by water as dispersing media, polyacrylic emulsion as basic material, defibered sepiolite and hollow glass microspheres as main functional additives. The thermal insulation effect and mechanism were studied by thermal insulation effect testing device and visible light reflectance tester. The results show that the optimum contents of functional additives are as follows: 8% defibred sepiolite fibers, 6% hollow glass microspheres. The coating could arrest heat transmission and reflect visible light effectively
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 44-46 (June 2008), p. 77-84 
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A viscoplastic constitutive model with void damage is developed to analyze themacroscopic mechanical response and damage mechanism of lead-free solder alloy in CBGApackaging under cyclic thermal loading. The constitutive model is implemented into ABAQUSthrough its user defined material subroutine. Two-dimensional nonlinear finite element analysis of aceramic ball grid array(CBGA) package is conducted to simulate the viscoplastic deformation anddamage failure process of the lead-free solder joint under cyclic thermal loading. The damage modelis helpful for optimization and reliability of electronic package
    Type of Medium: Electronic Resource
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