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981.
In this paper we consider the transmission problem of viscoelastic waves. That is, we study the wave propagations over materials consisting of elastic and viscoelastic components. We show that for this types of materials the dissipation produced by the viscoelastic part is strong enough to produce exponential decay of the solution, no matter how small is its size. We also show that the linear model is well posed. 相似文献
982.
Kun‐Li Wang Tseung‐Yuen Tseng Hung‐Lung Tsai Sheng‐Chieh Wu 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6861-6871
A series of poly(aryl ether)s were successfully prepared via aromatic nucleophilic substitution reaction from various bisphenols and a novel bipolar aryl difluoride monomer containing electron‐donor triphenylamine and electron‐acceptor 1,2,4‐triazole moieties. The poly(aryl ether)s exhibited excellent solubility in organic solvents such as dimethylformamide, chloroform, and tetrahydrofuran at room temperature. The poly(aryl ether)s showed high thermal stability with Td10 higher than 500 °C and glass transition temperatures (Tg) higher than 187 °C. The thin films of the poly(aryl ether)s indicated bistable resistive switching behavior with ON/OFF current ratios as high as 103. The switching on and switching off bias voltages of the poly(aryl ether)s were affected by the bisphenol moiety. The good resistive switching behavior of the poly(aryl ether)s made them promising candidates for future nonvolatile memory applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6861–6871, 2008 相似文献
983.
提出一种改进4管自体偏压结构SRAM/SOI单元. 基于TSUPREM4和MEDICI软件的模拟和结构性能的分析,设计单元结构并选取结构参数. 该结构采用nMOS栅下的含p+埋沟的衬底体电阻代替传统6管CMOS SRAM单元中的pMOS元件,具有面积小、工艺简单的优点. 该结构可以在0.5V的电源电压下正常工作,与6管单元相比,该单元瞬态响应正常,功耗只有6管单元的1/10,满足低压低功耗的要求. 相似文献
984.
985.
La-modified lead titanate (PLT) thin films were prepared by hot-wall type low pressure-metalorganic chemical vapor deposition
method. Pb(dpm)2, La(dpm)3, and titanium tetraisopropoxide were used as source materials. The films were deposited at 500°C under the low pressure of
1000 mTorr and then annealed at 650°C for 10 min in oxygen ambient. Sputter-deposited platinum electrodes and 180 nm thick
PLT thin films were employed to form MIM capacitors with the best combination of high charge storage density (26.7 μC/cm2 at 3V) and low leakage current density (1.5 × 10-7 A/cm2 at 3V). The measured dielectric constant and dielectric loss were 1000∼1200 and 0.06∼0.07 at zero bias and 100 kHz, respectively. 相似文献
986.
阵列和模式识别与气敏传感器 总被引:1,自引:0,他引:1
本文介绍几种模式识别方式,指出集成阵列和计算机模式识别是气敏传感器取得突破性进展的关键,有机材料是最有吸收力的敏感材料之一。 相似文献
987.
In this paper we introduce and study polynomial spline collocation methods for systems of Volterra integral equations with unknown lower integral limit arising in mathematical economics. Their discretization leads to implicit Runge-Kutta-type methods. The global convergence and local superconvergence properties of these methods are proved, and the theory is illustrated by a numerical example arising in the application of such equations in certain mathematical models of liquidation. 相似文献
988.
基于耦合的混沌神经网络建模方法 总被引:3,自引:0,他引:3
混沌状态下神经网络行为的研究是神经网络理论的一个新内容,由于它可能揭示脑活动的深层机制而广受重视,但是混沌网络信息处理能力进行大量和深入研究却遇到许多障碍,其问题之一是难以为网络系统选择适当的非线性参数。本文提出一种建立混沌神经网络模型的简单耦合方法,解决了选择参数的困难,计算机模拟结果表明,用该模型研究混沌状态下网络动态行为是有效的。 相似文献
989.
G Athithan 《Pramana》1995,45(6):569-582
This paper addresses itself to a practical problem encountered in using iterative learning rules for associative memory models.
The performance of a learning rule based on linear programming which overcomes this problem is compared with that of a representative
iterative rule by numerical simulation. Results indicate superior performance by the linear programming rule. An algorithm
for computing radii of maximal hyperspheres around patterns in the state space of a model is presented. Fractional volumes
of basins of attractions are computed for the representative iterative rule as well as the linear programming rule. With the
radii of maximal hyperspheres as weight factors for corresponding patterns to be stored, the linear programming rule gives
rise to the maximal utilisation of the state space. 相似文献
990.
有机-无机自由基盐(DBTTF)6PMo12O40·2H2O的合成、性质和晶体结构 总被引:1,自引:0,他引:1
用电解法制备了有机-无机自由基盐(DBTTF)6PMo12O40·2H2O.用红外光谱、电子光谱和电子自旋共振谱进行了表征,测定了其磁化率、导电性和单晶的晶体结构,该晶体属三斜晶系,P1空间群,晶胞参数为a=1.378 7(7)nm,b=1.420 4(2)nm,c=1.570 2(2)nm,α=104.570(8)°,β=103.41(2)°,γ=95.80(2)°,V=2.853(2)nm3,Z=1,Dc=2.142 Mg·m-3,R=0.072 7. 相似文献