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71.
This paper deals with a new boundary element method for analysis of the quasistatic problems in coupled thermoelasticity. Through some mathematical manipulation of the Navier equation in elasticity, the heat conduction equation is transformed into a simpler form, similar to the uncoupled-type equation with the modified thermal conductivity which shows the coupling effects. This procedure enables us to treat the coupled thermoelastic problems as an uncoupled one, A few examples are computed by the proposed BEM, and the results obtained are compared with the analytical ones available in the literature, whereby the accuracy and versatility of the proposed method are demonstrated. 相似文献
72.
We developed a multichannel fiber ferrule for a stable laser-diode array module. To apply YAG laser welding to parallel butt couple between the laser-diode and the single-mode fiber arrays, hermetically sealed and precisely aligned equi-interval fibers are required. We describe a V-grooved ceramic ferrule for embedding fibers. Fibers are fixed by soldering, using a flat ceramic lid and aligned with a 250 μm pitch. Our ferrule allowed a metallic, stem mounting laser-diode, to be fixed by YAG laser welding. All 30 samples tested have a leak rate of less than 1×10-10 atm·cc/s. Optical coupling of fabricated modules was 9.7±0.2 dB and coupling loss change from 25°C to 115°C was within 0.5 dB 相似文献
73.
Dielectric properties above the glass transition have been investigated for a series of bisphenol-A type epoxide prepolymers (388 ≤ M?w ≤ 2640). Dielectric measurements were performed over a frequency range of 50 Hz–1 MHz using a vertical parallel plate cell which was constructed in the laboratory. The dielectric α-relaxation for each prepolymer fits the empirical model of the Havriliak–Negami equation. The temperature dependence of the dielectric relaxation time τ is described by the Williams–Landel–Ferry (WLF) equation as well as that of the direct current conductivity σ, which can be measured using the same cell. The relationship between τ and σ, σ· τm = const, is derived from experimental results. The exponent m, which depends on the molecular weight of the prepolymer, is considered to correspond to the ratio of the segmental mobility to ionic mobility. The dielectric loss ε″ can be used as an indicator of the direct current conduction in the temperatures where the ionic component in ε″ becomes much larger than the dipole one. 相似文献
74.
Bargiela A. Pedrycz W. Tanaka M. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2003,33(3):288-301
In this paper, we present results of uncertain state estimation of systems that are monitored with limited accuracy. For these systems, the representation of state uncertainty as confidence intervals offers significant advantages over the more traditional approaches with probabilistic representation of noise. While the filtered-white-Gaussian noise model can be defined on grounds of mathematical convenience, its use is necessarily coupled with a hope that an estimator with good properties in idealised noise will still perform well in real noise. In this study we propose a more realistic approach of matching the noise representation to the extent of prior knowledge. Both interval and ellipsoidal representation of noise illustrate the principle of keeping the noise model simple while allowing for iterative refinement of the noise as we proceed. We evaluate one nonlinear and three linear state estimation technique both in terms of computational efficiency and the cardinality of the state uncertainty sets. The techniques are illustrated on a synthetic and a real-life system. 相似文献
75.
This paper deals with the thermal analysis of carbon nanotube (CNT) based composites by meshless element free Galerkin method.
Cylindrical representative volume element (cylindrical RVE) has been chosen to evaluate the thermal properties of nano-composites
using multi-domain and simplified approaches. The values of temperature have been calculated at different points and plotted
against RVE length and RVE radius. A sensitivity analysis of RVE as well as CNT dimensions has been carried out in detail.
The present computations show that the equivalent thermal conductivity is a function of CNT length, CNT radius, RVE length
and RVE radius. Based on present numerical simulations, an approximate formula is proposed to calculate the equivalent thermal
conductivity of nano-composites. The results obtained by simplified approach have been found in good agreement with those
obtained by multi-domain approach. 相似文献
76.
Tooru Tanaka Toshiyuki Yamaguchi Akihiro Wakahara Akira Yoshida Ryoichi Taniguchi Yatsuka Matsuda Masatoshi Fujishiro 《Solar Energy Materials & Solar Cells》2003,75(1-2):115-120
Radiation damages due to 8 MeV electron irradiation in electrical properties of CuInSe2 thin films have been investigated. The n-type CuInSe2 films in which the carrier concentration was about 3×1016 cm−3, were epitaxially grown on a GaAs(0 0 1) substrate by RF diode sputtering. No significant change in the electrical properties was observed under the electron fluence <3×1016 e cm−2. As the electron fluence exceeded 1017 e cm−2, both the carrier concentration and Hall mobility slightly decreased. The carrier removal rate was estimated to be about 0.8 cm−1, which is slightly lower than that of III–V compound materials. 相似文献
77.
Wei Wei Craig A. BennettRyuzo Tanaka Gang HouMichael T. Klein Jr. Michael T. Klein 《Fuel Processing Technology》2008
The complexity of many chemical and refining reaction systems and the thus-derived tedious and time-consuming process of building the associated kinetic models have been major obstacles in the use of fundamental kinetics in the solution of chemical engineering problems. This review summarizes work aimed at removing theses obstacles. Our recent work that has led to the enhancement of the Kinetic Modeler's Toolbox (KMT) and the development of the Kinetic Model Editor (KME) presents an end-to-end solution to the kinetic modeling process, including automated feedstock modeling, reaction network construction, kinetic rate estimation, model programming, process system configurations, model customizations, compilations, model execution and results analysis. 相似文献
78.
K Sugahara Y Tanaka S Yamada N Seno H Kitagawa SM Haslam HR Morris A Dell 《Canadian Metallurgical Quarterly》1996,271(43):26745-26754
We prepared a series of oligosaccharides from king crab cartilage chondroitin sulfate K after exhaustive digestion with testicular hyaluronidase, and determined the structures of four tetrasaccharides and a pentasaccharide by fast atom bombardment mass spectrometry, high performance liquid chromatography analysis of chondroitinase AC-II digests, and 500-MHz 1H NMR spectroscopy. The tetrasaccharides shared the common core structure GlcAbeta1-3GalNAcbeta1-4GlcAbeta1-3GalNAc with various sulfation profiles. One structure was GlcAbeta1-3GalNAc(4S)beta1-4GlcAbeta1-3GalNAc(4S), whereas three of them have the following hitherto unreported structures including a novel glucuronate 3-O-sulfate: GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcAbeta1-3GalNAc(4S), GlcAbeta1-3GalNAc(4S)beta1-4GlcA(3S)beta1-3GalNAc(4S), and GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcA(3S)beta1-3GalNAc(4S), where 3S or 4S represents 3-O- or 4-O-sulfate, respectively. The structure of the pentasaccharide was determined as GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcA(3S)beta1- 3GalNAc(4S)beta1-4GlcA. Chondroitinase ABC digestion of the tetrasaccharides with GlcA(3S) at the internal position destroyed the disaccharide unit containing GlcA(3S) derived from the reducing side and resulted in only the disaccharide unit from the non-reducing side. In contrast, these tetrasaccharides remained totally resistant to chondroitinase AC-II. The results indicated that it is necessary to reevaluate the disaccharide composition of chondroitin sulfate poly- or oligosaccharides purified from various biological sources, since they were usually determined after chondroitinase ABC digestion. It is probable that the structures containing GlcA(3S) would not have been detected. 相似文献
79.
F Imai T Suzuki T Ishibashi M Tanaka Y Akiyama Y Dohi 《Canadian Metallurgical Quarterly》1994,21(4):612-615
OBJECTIVE: We investigated the in vitro immunomodulatory effects of sulfasalazine on B cells in rheumatoid arthritis (RA). METHODS: Reversed hemolytic plaque assay and 3H-thymidine incorporation were measured. RESULTS: B cells from patients with RA showed hyperactivity to stimulation by Staphylococcus aureus Cowan I. Sulfasalazine significantly inhibited this B cell hyperactivity in a dose dependent manner. The kinetic study and a decrease in 3H-thymidine incorporation on Day 3 indicate that sulfasalazine inhibited the early phase (0-48 h) of B cell proliferation in these patients. Sulfapyridine also inhibited B cell hyperactivity in these patients, but 5-aminosalicylic acid and N-acetylsulfapyridin had no significant effect. CONCLUSION: Sulfasalazine exhibited a direct immunosuppressive effect on B cell hyperactivity in patients with RA, which may be responsible for its therapeutic effectiveness in this disorder. 相似文献
80.
Inoue Y. Kobayashi K. Tanaka E. Okamoto S. Tsuchiya Y. Takizawa K. 《Broadcasting, IEEE Transactions on》1996,42(3):259-265
In order to realize full-color electroluminescent (EL) displays, which are expected as a dominant candidate for the future multimedia flat panel display, blue EL devices with SrGa2S4:Ce have been prepared by molecular beam epitaxy (MBE). This paper proposes a novel deposition method employing Sr metal and Ga2S4 compound as the source materials. A single-phase SrGa2S4 layer is obtained in a Ga2S3/Sr flux ratio of 60 and at the growth temperature of 560°C. We have obtained the well-saturated blue with CIE color coordinates of x=0.14, y=0.14 and brighter blue EL devices made by optimizing the growth conditions in MBE. The maximum luminance of 70 cd/m2 in comparison with the 3 cd/m2 of our previous EL devices, is achieved at a driving frequency of 1 kHz 相似文献