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661.
高能激光武器的现状与发展趋势 总被引:11,自引:1,他引:11
任国光 《激光与光电子学进展》2008,45(9):62-69
高能激光武器即将走上战场,这必将引起未来战争发生革命性变化.评述和分析了美国正在研发的各种激光武器的任务性能、关键技术、最新进展、面临的挑战和发展趋势. 相似文献
662.
Arantxa Maestre Caro Silvia Armini Olivier Richard Guido Maes Gustaaf Borghs Caroline M. Whelan Youssef Travaly 《Advanced functional materials》2010,20(7):1125-1131
A 3‐aminopropyltrimethoxysilane‐derived self‐assembled monolayer (NH2SAM) is investigated as a barrier against copper diffusion for application in back‐end‐of‐line (BEOL) technology. The essential characteristics studied include thermal stability to BEOL processing, inhibition of copper diffusion, and adhesion to both the underlying SiO2 dielectric substrate and the Cu over‐layer. Time‐of‐flight secondary ion mass spectrometry and X‐ray spectroscopy (XPS) analysis reveal that the copper over‐layer closes at 1–2‐nm thickness, comparable with the 1.3‐nm closure of state‐of‐the‐art Ta/TaN Cu diffusion barriers. That the NH2SAM remains intact upon Cu deposition and subsequent annealing is unambiguously revealed by energy‐filtered transmission electron microscopy supported by XPS. The SAM forms a well‐defined carbon‐rich interface with the Cu over‐layer and electron energy loss spectroscopy shows no evidence of Cu penetration into the SAM. Interestingly, the adhesion of the Cu/NH2SAM/SiO2 system increases with annealing temperature up to 7.2 J m?2 at 400 °C, comparable to Ta/TaN (7.5 J m?2 at room temperature). The corresponding fracture analysis shows that when failure does occur it is located at the Cu/SAM interface. Overall, these results demonstrate that NH2SAM is a suitable candidate for subnanometer‐scale diffusion barrier application in a selective coating for copper advanced interconnects. 相似文献
663.
随着新一代信息技术与先进制造技术的深度融合,智能制造成为新时代高端装备制造企业转型升级的重要途径。通过分析在数字经济浪潮下,高端装备行业的趋势和企业发展过程中面临的机遇与挑战,提出了通过智能制造实现制造业的转型发展道路的思考,并就企业如何推进智能制造规划和建设提出了具体的建议。 相似文献
664.
为满足液晶面板尤其是大尺寸产品对高透过率不断提升的需求,进行负型液晶在ADS广视角技术中的研究。首先,介绍ADS技术的发展进程及主要特点,然后模拟分析负型液晶参数变化对ADS显示特性的影响,最后,利用mini cell对负型液晶和PI材料的进行实验室评价。液晶参数中:Δn影响透过率,|Δε|和K值影响响应时间和工作电压,γ1影响响应时间。负型液晶透过率比正型液晶提升约8%,但响应时间增加约50%,负型液晶与PI的匹配性及残像差于正型液晶,与PI材料的搭配对残像有显著影响。调整负型液晶参数可优化产品性能。负型液晶可大幅提高产品的透过率,但需要加快响应时间和提升残像水平。响应速度的提高除了需要降低液晶的黏度,还需在电极结构优化方面做更多努力,而残像水平的提升,除提高负型液晶材料本身的稳定性外,与其搭配的取向材料的研发也十分重要。 相似文献
665.
非结构网格的生成及新型数据类型的应用 总被引:3,自引:0,他引:3
本文基于 Delaunay三角化方法及局部重组的阵面推进法,给出了任意形状平面区域的非结构化网格剖分方法。文中对加点方法及数据结构和存取模式进行了改进,同时应用链表结构、动态数组和派生类型的数据变量,对算法进行优化,节省了计算内存,提高了网格的生成效率。本文研究为特殊计算区域的三维非结构化网格的生成提供了基本方法。 相似文献
666.
Nalâv Gülpinar Gautam Mitra István Maros 《Computational Optimization and Applications》2002,21(1):71-93
In this paper, we investigate how an embedded pure network structure arising in many linear programming (LP) problems can be exploited to create improved sparse simplex solution algorithms. The original coefficient matrix is partitioned into network and non-network parts. For this partitioning, a decomposition technique can be applied. The embedded network flow problem can be solved to optimality using a fast network flow algorithm. We investigate two alternative decompositions namely, Lagrangean and Benders. In the Lagrangean approach, the optimal solution of a network flow problem and in Benders the combined solution of the master and the subproblem are used to compute good (near optimal and near feasible) solutions for a given LP problem. In both cases, we terminate the decomposition algorithms after a preset number of passes and active variables identified by this procedure are then used to create an advanced basis for the original LP problem. We present comparisons with unit basis and a well established crash procedure. We find that the computational results of applying these techniques to a selection of Netlib models are promising enough to encourage further research in this area. 相似文献
667.
The internal propagation of fusion flame with the strong shock of a laser driven plasma block for advanced nuclear fuel ignition
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An accelerated skin layer may be used to ignite solid state fuels. Detailed analyses were clarified by solving the hydrodynamic equations for nonlinear force driven plasma block ignition. In this paper, the complementary mechanisms are included for the advanced fuel ignition: external factors such as lasers, compression, shock waves, and sparks. The other category is created within the plasma fusion as reheating of an alpha particle, the Bremsstrahlung absorption, expansion, conduction, and shock waves generated by explosions. With the new condition for the control of shock waves, the spherical deuterium-tritium fuel density should be increased to 75 times that of the solid state. The threshold ignition energy flux density for advanced fuel ignition may be obtained using temperature equations, including the ones for the density profile obtained through the continuity equation and the expansion velocity for the r ≠ 0 layers. These thresholds are significantly reduced in comparison with the ignition thresholds at x = 0 for solid advanced fuels. The quantum correction for the collision frequency is applied in the case of the delay in ion heating. Under the shock wave condition, the spherical proton-boron and proton-lithium fuel densities should be increased to densities 120 and 180 times that of the solid state. These plasma compressions are achieved through a longer duration laser pulse or X-ray. 相似文献
668.
We prove some comparison results for the periodic boundary value problem related to a first‐order functional differential equation of advanced type. These maximum principles provide uniqueness results for nonlinear differential equations with advanced arguments. By a change of variable, we deduce analogous results for fuctional differential equations with delayed arguments (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
669.
M. Modesti S. Besco V. Causin J.W. Gilman P.C. Trulove M. Zammarano 《Polymer Degradation and Stability》2007,92(12):2206-2213
Acrylonitrile-butadiene-styrene (ABS) polymer/clay nanocomposites were produced using an intercalation-adsorption technique from polymer in solution: polymer/clay suspensions were subjected to ultrasonic processing to increase the effectiveness of mixing. Several kinds of organically modified layered silicates (OMLS) were used to understand the influence of the surfactant nature on the intercalation-exfoliation mechanism. We show that only imidazolium-treated montmorillonite (DMHDIM-MMT) is stable at the processing temperature of 200 °C, used for hot-pressing, whereas alkyl-ammonium modified clays show significant degradation.The morphology of ABS based polymer nanocomposites prepared in this work was characterized by means of wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Dynamic-mechanical analysis (DMA) was used to determine the storage modulus and damping coefficient as a function of temperature, and to investigate the correlations between mechanical properties and morphology of the nanocomposites. The thermal stability was assessed by means of thermogravimetric analysis (TGA). DMA and TGA show that the nanocomposites based on imidazolium-modified clay out-perform the nanocomposites based on quaternary-ammonium-modified clays in terms of mechanical properties and thermal stability. 相似文献
670.
两种不同粒径的SBR粒子对透明ABS树脂力学性能影响 总被引:1,自引:0,他引:1
从SBR橡胶粒子出发,采用乳液原位悬浮聚合方法合成了一系列透明ABS树脂.采用小粒径SBR橡胶粒子虽然可以获得透明性良好的透明ABS树脂,但树脂的抗冲性能较差.采用大粒径SBR橡胶粒子ABS树脂的透明性明显下降.采用由粒径分别为400nm和70nm两种SBR橡胶粒子所组成的双峰粒子(指粒度分布谱上有两个峰)体系,当二者比例在4/6~6/4范围内,总橡胶粒子含量为15%~18%时,所得到的透明ABS树脂冲击强度已经达到90~120J/m,透光率超过80%.初步探讨了不同增韧体系的ABS树脂的脆韧转变关系;研究了不同粒径橡胶粒子的协同增韧效应.确定了由SBR双峰粒子增韧体系获得具有良好力学和透光性能的ABS树脂的基本条件. 相似文献