6,456 research outputs found
Li yi zhong de mei shu Wu Hong Zhong guo gu dai mei shu shi wen bian = Art in its ritual context : essays on ancient Chinese art
No full textBen shu xuan yi le zhu ming mei shu shi jia wu hong jiao shou zi 1985 nian yi lai fa biao de 31 pian lun wen. zhe xie lun wen wei rao zhe " li yi mei shu " zhe yi ji ben gai nian tao lun le zhong guo shang gu he zhong gu mei shu zhong de duo xiang yi shu chuan tong he xing sh
Intrinsic Stress Dependence of C-axis Orientation of PbTi03 Thin film by D.C Magnetron Sputtering
No full textAsymptotic homogenization of viscoelastic composites with periodic microstructures
No full textA systematic way of obtaining the effective viscoelastic moduli in time and frequency domain is presented for viscoelastic composites with periodic microstructures. The problem of estimating the effective moduli is formulated using the asymptotic homogenization method. For theoretical aspects, the memory effects due to the homogenization are shown in general form and a sufficient condition for the effects to disappear is fully discussed. The computational procedure is divided into two steps. The effective relaxation moduli are computed in Laplace transformed domain and are numerically inverse-transformed into time domain. The effective complex moduli are then readily obtained by using simple formulae of the Fourier transform. Several numerical examples are presented to illustrate and verify present approach and to discuss the memory effects. (C) 1998 Elsevier Science Ltd
Out-of-Vocabulary Rejection using Phone Filler Model in Variable Vocabulary Word Recognition
No full textIntrinsic stress dependence of c-axis orientation ratio in PbTiO3 thin films deposited by reactive sputtering
No full textHighly c-axis oriented lead titanate (PbTiO3) thin film, having a perovskite structure, was prepared on magnesium oxide (MgO) (100) single crystal using multiple cathode dc-magnetron sputtering at 600 degrees C. The film was annealed at 700 degrees C for up to 8 h. Both the c-axis orientation ratio P and c-axis lattice parameter of the film decreased with the increase of the annealing time. It was confirmed that the decrease of the c-axis lattice parameter with the annealing time was due to the relaxation of the intrinsic stress generated during deposition. These experimental results suggested that P was related to the intrinsic stress. The film deposited at various working pressures was examined in detail to confirm the intrinsic stress effect of P. P of 95% at 8 mTorr decreased to 60% at 70 mTorr. The pressure dependence of P was explained by the intrinsic stress change. Regardless of the sputtering condition, all P's were reduced to 40% after annealing at 700 degrees C for 8 h. The difference in P between the before and after annealing was caused by the relaxation of the intrinsic stress. It was supposed that the remaining 40% of P after the heat treatment was caused, in the most part, by the ferroelectric phase transition. (C) 1997 American Vacuum Society
Design of microstructures of viscoelastic composites for optimal damping characteristics
No full textAn inverse homogenization problem for two-phase viscoelastic composites is formulated as a topology optimization problem. The effective complex moduli are estimated by the numerical homogenization using the finite element method. Sensitivity analysis shows that the sensitivity calculations do not require the solution of any adjoint problem. The objective function is defined so that the topology optimization problem finds microstructures of viscoelastic composites which exhibit improved stiffness/damping characteristics within the specified operating frequency range. Design constraints include volume fraction, effective complex moduli, geometric symmetry and material symmetry. Several numerical design examples are presented with discussions on the nature of the designed microstructures. From the designed microstructures, it is found that mechanism-like structures and wavy structures are formed to maximize damping while retaining stiffness at the desired level. (C) 2000 Published by Elsevier Science Ltd. All rights reserved
Modeling and analysis on the internal impact of a Stewart platform utilized for spacecraft docking
No full textIn this paper, impacts at the joints of a closed-chain mechanism are modeled and analyzed. It is assumed that a Stewart platform is attached to one end of a spacecraft to be utilized as a docking platform and the spacecraft docks with another spacecraft. When the spacecrafts dock with each other, impact will rise at the docking point and the impact is absorbed by the docking platform. Although the impact at the contact point is very large, most of the impact is absorbed by the docking platform and negligible impact is transmitted to the spacecraft. The docking platform can absorb the shock by inertial effect, not by damping or friction. To show this, modeling of the internal impulses at the joints of a multi-body system is introduced and the internal impulses of the docking platform are analyzed by the modeling method.This work was supported in part by the Brain Korea 21 project
Process development for production Of recombinant human insulin-like growth factor-I in Escherichia coli
No full textFed-batch cultures were carried out to overproduce human insulin-like growth factor I (IGF-I) in Escherichia coli. The effects of carbon sources (glucose or glycerol) and induction time on cell growth and IGF-I production were investigated in more detail. Glycerol was a better carbon source than glucose for IGF-I production in fed-batch culture. Induction at the mid-exponential phase with glycerol as a carbon source in the pH-stat fed-batch culture was optimal for IGF-l production. Under this condition, 2.8 g L-1 of fusion IGF-I was produced as inclusion bodies. We have also developed downstream processing for preparative scale purification of IGF-I from the fusion protein produced by the fed-batch culture using glycerol as a carbon source. After the fusion protein expressed was solubilized in 8 M urea and cleaved with hydroxylamine, the released IGF-I was purified by cation exchange chromatography, refolding and preparative scale reverse phase HPLC (rp-HPLC) to give recombinant IGF-I of >98% purity. The biological activities of the purified IGF-I were measured and found to be identical to those of commercial IGF-I.Part of this work was presented at the APBioCheC'97 in Beijing. This work was supported by the Ministry of Science and Technology
Supplemental material for Parameter analysis of damaged region for laminates with matrix defects
No full textSupplemental Material for Parameter analysis of damaged region for laminates with matrix defects by ZQ Huang, SH Yi, HX Chen and XQ He in Journal of Sandwich Structures and Materials</p
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