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  • 1
    Electronic Resource
    Electronic Resource
    Study of the factors affecting the broadening of the photoluminescence spectra of InGaAs/InP quantum wires (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 4161-4166 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The origin of the observed large half width of photoluminescence spectra for InGaAs/InP quantum wires fabricated by electron beam lithography and reverse-mesa wet etching have been investigated. First, we studied size fluctuations in the fabricated wires using an atomic force microscope. We also studied other factors that can affect the photoluminescence half width. We found that the interface carrier concentration and size fluctuations play dominant roles in shaping the luminescence spectrum for wires narrower than 200 A(ring). For wider wires, the carrier concentration was found to be a factor in the broadening. These results indicate that a large half width itself does not directly mean a degradation of device performance, but the amount of size fluctuations limits it.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355998
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  • 2
    Electronic Resource
    Electronic Resource
    Clear energy level shift in ultranarrow InGaAs/InP quantum well wires fabricated by reverse mesa chemical etching (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 720-722 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have fabricated ultranarrow InGaAs/InP buried quantum well wires by means of electron beam lithography and reverse mesa wet etching. Owing to the reverse mesa etching profile, the lateral dimension of the wires has been reduced to 10 nm. Furthermore, we investigated the optical characteristics of these wires by photoluminescence and observed, for the first time, clear dependence of luminescence wavelength upon the wire width even for wires down to 10 nm, which is well explained by the theoretical calculation. The blue-shifted shoulder structures were also observed and they were assigned theoretically to be the second quantized level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104526
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  • 3
    Electronic Resource
    Electronic Resource
    Geometrical shape dependent polarization anisotropy in electroluminescence from InGaAs/InP quantum wires (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1094-1096 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The polarization properties of edge-emitted electroluminescence from InGaAs/InP quantum wires fabricated by reverse-mesa wet etching, electron-beam lithography, and overgrowth, are investigated. Strongly TE polarized electroluminescence from relatively wide wires approaches isotropy as the wires become narrower. The observed dependence on wire size is attributed to a transition from a two-dimensional to a one-dimensional system. The implication is that quantum wires could potentially be applied to polarization-controlled devices, such as polarization insensitive optical amplifiers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.108752
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  • 4
    Electronic Resource
    Electronic Resource
    Gate-voltage dependence of the critical current of the superconducting field effect transistor (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 2473-2475 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The saturation of the critical current as a function of the gate voltage found in the Nb-Si-Nb superconducting field effect transistor is analyzed numerically using the de Gennes expression for the proximity effect. According to the analysis, (i) the Schottky barrier effect is found to be negligible under experimental conditions, (ii) mobility of silicon fitted to the experimental curve shows a power relation to the gate voltage with exponent of about −0.81. This exponent is consistent with the results from independent experiments and a simple theory of surface scattering. The results indicate that the surface scattering effect causes the saturation phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.108156
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  • 5
    Electronic Resource
    Electronic Resource
    High-n helicity-induced shear Alfvén eigenmodes (1992)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 4 (1992), S. 1115-1121 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The high-n helicity-induced shear Alfvén eigenmodes (HAE) are considered both analytically and numerically for the straight helical magnetic system, where n is the toroidal mode number. The eigenmode equation for the high-n HAE modes is derived along the field line and, with the aid of the averaging method, is shown to reduce to the Mathieu equation asymptotically. The discrete HAE modes are shown to exist inside the continuum spectrum gaps. The continuous spectrum gaps appear around ω2=ω2A[N(lι(large-closed-square)−m)/2]2 for N=1,2,..., where ωA is the toroidal Alfvén transit frequency, and l, m, and ι(large-closed-square) are the polarity of helical coils, the toroidal pitch number of helical coils, and the rotational transform, respectively. For the same ωA and ι(large-closed-square), the frequency of the helical continuum gap is larger than that of the continuum gap in tokamak plasmas by ||l−ι(large-closed-square)−1m||. The polarity of helical coils l plays a crucial role in determining the spectrum gaps and the properties of the high-n HAE modes. The spectrum gaps near the magnetic axis are created by the helical ripple with circular flux surfaces for l=1, and ≥3 helicals. For l=2 helical systems, the spectrum gaps are created by the ellipticity of the flux surfaces. These analytical results for the continuum gaps and the existence of the high-n HAE modes in the continuum gaps are confirmed numerically for the l=2 case, and it is found that the HAE modes exist for mode structures with the even and the odd parities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860119
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  • 6
    Electronic Resource
    Electronic Resource
    Differential expression of three members of the AMT1 gene family encoding putative high-affinity NH4+ transporters in roots of Oryza sativa subspecies indica (2003)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 26 (2003), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: In order to investigate the molecular basis of high-affinity ammonium absorption by roots of rice plants (Oryza sativa subspecies indica) the expression patterns of three members of the AMT1 family of genes in rice seedling roots in response to altered nitrogen provision and diurnal changes in irradiance were examined. The 13NH4+ influx and transcript levels of OsAMT1.1 in roots decreased several fold within 48 h when plants acclimated to 10 µm external NH4+ for 3 weeks were transferred to 10 mm NH4+. Likewise when plants acclimated in 10 mm NH4+ were transferred to 10 µm NH4+, there was an equally rapid up-regulation of OsAMT1.1 and 13NH4+ influx in the roots. Changes in transcript abundance of OsAMT1.2 following these treatments were approximately 50% less than in OsAMT1.1, and changes of OsAMT1.3 expression were even less. By contrast, in response to the diurnal changes of irradiance, root transcript abundance of OsAMT1.3 and 15NH4+ influx increased approximately three-fold late in the photoperiod, whereas OsAMT1.1 and OsAMT1.2 exhibited only modest changes. The present results suggest that high-affinity NH4+ influx is differentially regulated at the transcriptional level through the expression of three members of the OsAMT1 family of genes in roots of rice seedlings in response to changes of N status and daily irradiance. In general, these findings are in agreement with earlier observations in Arabidopsis and tomato.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.2003.01023.x
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of long-term cigarette smoking on immunoglobulin E-mediated allergy, pulmonary function, and high-resolution computed tomography lung densitometry in elderly patients with asthma (2004)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 34 (2004), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Smoking is the most important cause of chronic obstructive pulmonary disease (COPD). However, the influence of cigarette smoking on the pathogenesis of asthma in the elderly remains controversial. This study attempted to clarify the influence of cigarette smoking on elderly asthmatics.Methods Forty-eight asthmatics over 70 years old (25 ex-smokers and 23 never-smokers) and 20 patients with COPD over 70 years old (all ex-smokers) were studied to determine the influence of cigarette smoking on IgE-mediated allergy (total IgE, IgE antibodies against inhalant allergens, bronchial hyper-responsiveness (BHR), generation of leukotriene (LT) B4 and C4), pulmonary function, and the relative area of lung showing attenuation values less than −950 Hounsfield units (RA950) on high-resolution computed tomography scans.Results The incidence of positive IgE antibodies against inhalant allergens, BHR, and the generation of leukotriene B4 (LTB4) by leucocytes were significantly increased in patients with a history of smoking compared with those without. Residual volume (%RV) was significantly increased, and diffusing capacity for carbon monoxide was significantly decreased in ex-smokers with asthma and COPD compared with never-smokers with asthma. Inspiratory RA950 and ratio of expiratory RA950 to inspiratory RA950 were significantly larger in asthmatics with a smoking history than in those without, and in COPD patients than in asthmatics.Conclusion Cigarette smoking enhances the production of IgE antibodies, BHR, and generation of LTB4 by leucocytes in elderly asthmatics. Increased hyper-inflation or emphysematous changes of the lungs expressed by increased RA950, closely related to %RV, was more frequently observed in ex-smokers compared with never-smokers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2222.2004.01844.x
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  • 8
    Electronic Resource
    Electronic Resource
    Interfacial fatigue crack propagation in Ni-base superalloy protective coatings (2001)
    Oxford, UK : Blackwell Science Ltd
    Fatigue & fracture of engineering materials & structures 24 (2001), S. 0 
    Details
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: It is important to control the interface strength of coatings and composite materials; a feature that has been noted for many years. However, how can interface strength be evaluated and controlled? In order to explore this aspect, subcritical fatigue crack growth behaviour was investigated along the interface of a CoNiCrAlY coated Ni-Base superalloy. According to the traditional fatigue test methodology, fatigue crack propagation tests were carried out, using double cantilever beam specimens. The resistance to the fatigue crack propagation was successfully evaluated by a fracture mechanics approach. Particular attention was given to the effects of surface finish of the substrate as a coating parameter, the test temperature, and long-term thermal ageing after the coating.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-2695.2001.00452.x
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  • 9
    Electronic Resource
    Electronic Resource
    Palatal plate of different designs for the suppression of masseter muscle activity during sleep. A challenge to the concept of placebo splint (2002)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 29 (2002), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Several designs of palatal appliance have been reported for the treatment of craniomandibular disorders. However, the effect of these appliances has not yet been fully clarified. This study aimed to reveal the effect of palatal appliances of different design on masseter muscle activity during sleep.Four volunteers (three women and one man, mean age 36·0 years) were used in this study. For each subject, four different types of palatal appliances were used. The palatal appliances were (1) horse shoe type (1 mm thick), (2) thin appliance which covered the whole palate (1 mm thick), (3) thick appliance which filled the palatal concavity and (4) appliance with half the thickness of the third appliance.These appliances were worn for 1 week in a randomized sequence with 1-week interval between each appliance. Right masseter muscle EMG was recorded three nights per week at home. The EMG signal longer than 0·25 s was classified as a burst and a signal shorter than 0·25 s was classified as a brief burst of fragmentary myoclonus (FM).Mean number of burst per hour for four subjects were 7·99 ± 7·32, 3·52 ± 1·95, 5·90 ± 3·99, 2·87 ± 2·87 and 9·96 ± 6·02 for base line, appliance 1, 2, 3 and 4, respectively. Mean number of FM per hour were 136·86 ± 69·88, 90·53 ± 41·19, 99·49 ± 39·29, 71·66 ± 24·66 and 144·39 ± 42·97, respectively. From these results, it was suggested that the thick palatal appliance suppressed the masseter muscle activity during sleep most effectively. Also, the results for appliance 4 questioned the concept of placebo effect for non-occlusal appliances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.2002.01026_28.x
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  • 10
    Electronic Resource
    Electronic Resource
    Magnetic resonance imaging analysis on the relationship between anterior disc displacement and balancing-side occlusal contact (2003)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 30 (2003), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: summary  The purpose of this study was to evaluate the relationship between balancing-side occlusal contact patterns and the prevalence of the internal derangement of the temporomandibular joint (TMJ). Forty-one patients were used for the magnetic resonance image (MRI) analysis of TMJ and occlusal examination. Balancing-side occlusal contact patterns observed during mandibular lateral excursive movements were classified into the three following categories: group A, simultaneous balancing-side contact, group B, balancing-side contact (with clenching only) and Group C, no balancing-side contact (with or without clenching). By the occlusal examination of 57 sides, 31·6% showed group A, 8·8% showed group B and 59·6% showed group C contact. Group A could not be observed in the patient group with normal disc position. In the disc displacement group, the prevalence of group A, group B and group C were 40·9, 6·8 and 52·3%, respectively. The higher prevalence of simultaneous balancing-side contact was revealed to be associated with articular disc dislocation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.2003.01000.x
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