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991.
992.
Z. L. Wang C. J. Niu J. F. Ma J. Z. Ni 《Journal of Thermal Analysis and Calorimetry》1994,41(4):899-907
Rare earth complexes ofm-nitrobenzoic acid (LnL3·2H2O,Ln=La-Lu and Y, except Pm, HL=m-nitrobenzoic acid) were synthesized and characterized by elemental analysis, chemical analysis, IR spectroscopy and X-ray diffraction analysis. The dehydration behaviour of these complexes was studied in detail by means of TG-DTA and DSC. Dehydration occurs over the temperature range 76–215°C, and the temperature of formation of the anhydrous complexes decreases with increasing atomic number of the rare earth. The activation energies and enthalpy changes for te dehydration were obtained. 相似文献
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The development of microfluidic (lab-on-a-chip) technology requires local control of fluid flow in the microchannels. Conventional microvalve approaches involve moving parts and/or complicated fabrication techniques, which makes them unreliable and prevents inexpensive integration in microanalytical systems. We have developed a simple low cost method for regulating fluid flow in microchannels that is compatible with existing microfabrication techniques and eliminates the need for moving parts. We use an electrical signal to stimulate silver deposition on a thin solid electrolyte layer in a small region of a microchannel. Since fluid flow is dominated by the nature of the channel surface, the electrodeposited silver changes the fluid–surface interaction and the effect can be used to control the movement of the fluid. Increases in the contact angles of both water and methanol, by 20 and 27 respectively, have been demonstrated. Such changes in hydrophobicity are sufficient to retard or stop capillary or external pressure-driven fluid flow in typical microchannels. 相似文献
996.
M. Ishii Y. Kuwano S. Asaba T. Asai M. Kawamura N. Senguttuvan T. Hayashi M. Koboyashi M. Nikl S. Hosoya K. Sakai T. Adachi T. Oku H. M. Shimizu 《Radiation measurements》2004,38(4-6):571-574
Lithium tetraborate single crystal doped with Cu seems to be a promising new material for neutron detection. With the presence of Li and B, both having large cross section for neutron capture, efficient neutron detection is expected with high-energy deposits. In the present work, we chose 14 different dopants from Ia, Ib, IIIa, IVa and Va groups in the periodic table besides the rare earth Ce ion. The crystals were grown to a size of 20 mm in diameter and 70 mm in length by vertical Bridgman method. The grown crystals were characterized by optical transmittance and excitation–emission studies. Transmittance and emission characteristics of Ce-doped lithium borate glass are also reported. 相似文献
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The plasticity theory has been successfully used for describing the nonlinear deformation of laminated composite materials
under a monotonically increasing loading. Generally, several tests are needed to determine the parameters of the plastic potential
for a laminate. We explore an alternative approach and obtain the plastic potential by using theoretical considerations based
on a laminate analysis. The model is shown to provide an accurate prediction for the response of a cross-ply glass/epoxy laminate
under uniaxial tensile loading at different angles to the material orthotropy axes.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 43, No. 3, pp. 309–318, May–June, 2007. 相似文献
999.
In this paper, an optimal control problem for glass cooling processes is studied. We model glass cooling using the SP1 approximations to the radiative heat transfer equations. The control variable is the temperature at the boundary of the domain. This results in a boundary control problem for a parabolic/elliptic system which is treated by a constrained optimization approach. We consider several cost functionals of tracking‐type and formally derive the first‐order optimality system. Several numerical methods based on the adjoint variables are investigated. We present results of numerical simulations illustrating the feasibility and performance of the different approaches. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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