基于混合遗传算法的树状注水管网拓扑优化

以投资最小为目标函数,以井间隶属关系的惟一性、连接注水井数量等限制为约束条件,建立了树状注水管网拓扑优化数学模型.根据模型特点,将优化问题分为分配层和几何层,分别采用遗传算法和非线性优化方法进行求解.并对遗传算法的操作过程进行了改进,调整了适应函数,采用随机多父辈适应函数值加权交叉和多种变异操作,结合了模拟退火算法,并给出了初温的确定方法,改进了选择复制操作,从而形成了混合遗传算法.该算法能够有效地提高收敛速度,避免早熟收敛.利用算例说明了该方法的有效性.     

Luminescence Characterization of Mg Doped Y2O2S:Ti Long Afterglow Phosphor

Y1.94-xMgxO2S:0.06Ti (0≤x≤0.10) phosphors with long afterglow were synthesized by solid state reaction route. The photoluminescence spectra, decay curves, thermoluminescent spectra and chromaticity coordinate curves were investigated. The results show that the luminescence intensity of Y1.94-xMgxO2S:0.06Ti (0≤x≤0.10) phosphors decrease gradually with increasing Mg2 ion content, and the shape of luminescence spectra and chromaticity coordinate change as well. Furthermore, two thermoluminescent peaks in single Ti-doped Y2O2S sample are found at 91.8 and 221.5 ℃, respectively. Nevertheless, significant different spectra were found for the Mg, Ti co-doped Y2O2S samples that three thermoluminescence peaks appear at 52.3, 141.7 and 226.8 ℃, respectively. These results indicate that the co-doped Mg ion changes the inherent trap depth of single Ti-doped Y2O2S:Ti phosphor, and induces simultaneously a new trap level in the Y1.94-xMgxO2S:0.06Ti phosphor. Based on the analysis of thermoluminescent spectra, photoluminescent spectra, decay curve and crystal structure defect, it was proposed that the varied structure defect and introduced new trap level by the doped Mg2 ions should be responsible for reducing luminescence intensity and varying color in the Y1.94-xMgxO2S:0.06Ti phosphor.     

示例学习的扩张矩阵理论

本文提出示例学习的一种计算理论,扩张矩阵论.根据这个理论,示例学习中一些主要最优化问题被证明是NP难题,并给出这些难题的近似解法及下界的估计.     

Effects of Substrate Temperatures on the Structure and UV-shielding Properties of TiO_2-CeO_2 Films Deposited on Glass by Radio-frequency Magnetron Sputtering

1Introduction Theultravioletrays(UV)insunlight(-4%)cantransmitintoroomthroughcommonfloatglass,theUVcanmakethematerialsintheroom,eg,paper,furni ture,textilefabricandplastics,becoloredanddeterio rated.ShieldingfromUVirradiationisofinterestinmanyfields.Formu…     

A novel SAL-PINSCH quantum-well laser structure for a pinched beamdivergence

Summary form only given. An edge-emitting strained AlGaAs/InGaAs/GaAs quantum-well laser structure is reported. It has a periodic index separate confinement heterostructure (PINSCH) optical confinement layers for a small beam divergence and high output power. Preliminary measurements of AR/HR-coated self-aligned ridge waveguide lasers show a CW output power of up to 350 mW and a 20° transverse beam divergence at a 980-nm lasing wavelength. This low beam divergence results in a high coupling efficiency of 51% into single-mode fibers. The expanded optical field in PINSCH confinement layers significantly pinches the transverse beam divergence and increases the maximum output power     

镁质瓷泥浆流变性能的改进

滑石质瓷是一种高性能瓷的材料，但由于其泥浆的稠化性及泥料塑性差，阻碍了滑石质瓷的大量生产。实验表明：引入长石作助熔剂并加入适量粘土，可以改进泥料塑性及泥浆流变性能，使烧成变形度小，机械强度提高，能较好地满足制品成型的工艺要求。实验中设计了多组配料，分析比较烧后试样的性能测试结果，确定最佳配方及烧结温度。     

制氢尾气二氧化碳回收装置设计

对制氢尾气二氧化碳的回收装置进行了简捷设计，流程分析，并对换热装置的换热量和传热面积给出了算法和有关数据。     

V_2O_5催化剂上甲醇乙醇一步合成醛类化合物的研究

在固定床反应器上研究了V2O5催化剂上甲醇、乙醇一步催化合成异丁醛等醛类化合物的反应。当反应在常压、350℃、进料比n(甲醇)/n(乙醇)=2、空速2.0h-1条件下进行时,乙醇转化率为89.05%,总醛产率达87.3%,其中异丁醛、乙醛、丙醛产率分别为16.71%、52.03%、18.56%,其余为丙醇、甲醛等化合物。当空速降为为0.5h-1时,乙醇转化率达到97.04%,异丁醛产率达29.07%,但总醛收率降为69.6%。该反应系统的反应历程被探讨。     

大伙房水库输水工程隧洞结构应力仿真分析

应用有限元法对辽宁省大伙房水库输水工程主体隧洞结构进行了仿真分析,从而得到隧洞结构的应力分布规律,研究确定薄弱部位并采取相应的稳定措施,以便保证隧洞施工的安全与经济。