191 resultados para 325-M0052C


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Thermocapillary motion of a drop in a uniform temperature gradient is investigated numerically. The three-dimensional incompressible Navier-Stokes and energy equations are solved by the finite-element method. The front tracking technique is employed to describe the drop interface. To simplify the calculation, the drop shape is assumed to be a sphere. It has been verified that the assumption is reasonable under the microgravity environment. Some calculations have been performed to deal with the thermocapillary motion for the drops of different sizes. It has been verified that the calculated results are in good agreement with available experimental and numerical results. (C) 2003 Elsevier Ltd. All rights reserved.

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在单脉冲激波管中,用对比速率法研究了TiCl_4的裂解。从自由基清扫剂环已烷C_6H_(12)的诱发裂解中产生的C_2H_4的测量,确定反应的机制,并测量得到了TiCl_4裂解初始过程的反应速率常数:k(TiCl_4→TiCl_3•+Cl•)=10~(16.4)exp(-(41700)/T)sec~(-1)。

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本文提出了一个用控制锗窗温度的办法实现CO_2激光器选频的简单方案。定量地讨论了锗窗温度变化对腔频的影响及所引起的其相干反射极大的频移,并结合介质增益分析了它们对激光输出谱线的影响。实验证实该选频方案是切实可行的。

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科技论文写作对总结科学研究的创新发现是至关重要的。本文作者对如何撰写或写好科技论文,从论文写作的基本元素及常见问题等方面言简意赅地提出了很有意义的见解。

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脉搏波传播速度的变化往往是血管弹性程度发生变化的最早体征,因此脉搏波速度的检测对动脉硬化等疾病的诊断有较高的参考价值,其检测精度主要取决于波速参考点的提取算法.在分析实际采集的脉搏压力波信号特征的基础上,对波峰、波足等特征点进行了识别,并提出了一种根据脉搏波前沿内斜率最大值点的个数和位置确定惟一波速参考点的新算法.临床实验证明,新方法能够有效地提取脉搏波速度,有助于动脉血管弹性程度的辅助诊断.

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通过对固体中波动问题的模拟建立了一种光滑粒子法的新形式,一种运用SPH的核函数的类似有限体积法的计算方法.通过对统计体积的修正以及对边界粒子的核函数修正,较好地解决了SPH方法中长期以来制约其被广泛应用的主要问题之一边界条件的表述.在此基础上成功地在光滑粒子法中实现了透射边界条件的模拟.同时利用反卷积修正使得较大粒子间距下的计算结果的精度大大提高.这种方法不但保持了SPH的简单性,而且很容易实现应力边界条件.

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国家自然科学基金

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利用坐标旋转方法和Kogelnik耦合波理论,建立了光轴方向任意时单轴晶体中体光栅布拉格衍射的耦合波方程,分析了LiNbO3晶体的光轴方向对光折变体全息光栅的各向同性和各向异性布拉格衍射性质的影响。模拟计算表明,在给定光栅的结构参量时,通过适当选择光轴方向角可以使得光折变体光栅的各向同性和各向异性布拉格衍射的衍射效率达到最大,给出了相应类型的衍射效率取得最大值时晶体光轴的大致方向。这些理论分析为光折变体全息光学器件的优化设计和进一步广泛应用提供了很好的理论参考依据。

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Immersion lithography has been considered as the mainstream technology to extend the feasibility of optical lithography to further technology nodes. Using proper polarized illumination in an immersion lithographic tool is a powerful means to enhance the image quality and process capability for high numerical aperture (NA) imaging. In this paper, the impact of polarized illumination on high NA imaging in ArF immersion lithography for 45 nm dense lines and semi-dense lines is studied by PROLITH simulation. The normalized image log slope (NILS) and exposure defocus (ED) window are simulated under various polarized illumination modes, and the impact of polarized illumination on image quality and process latitude is analyzed. (C) 2007 Elsevier GmbH. All rights reserved.

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为提高国内惯性约束聚变(ICF)装置的焦斑平滑能力,在对光谱色散平滑(SSD)技术理论分析的基础上,开展相关实验并研究其平滑机制。实验结合另一种焦斑平滑技术——分布式相位板(DPP)比较分析光谱色散平滑技术应用下的焦斑均匀性的变化。实验表明,利用光谱色散平滑技术中的正弦相位调制对光谱展宽并色散后,在色散方向上的焦斑均匀性有明显改善,120μm内的光强调制被平滑,其平滑能力依赖于光谱色散平滑技术参量的选择;焦斑的低频光谱强度变化很小,但中高频光谱强度下降,焦斑质量有良好的改善,焦斑的不均匀性从40%降低到1

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合成了2-(2-氨基-6-乙氧基苯并噻唑基偶氮)-5-(N,N-二乙基氨基)三氟甲基磺酰苯胺偶氮染料(EBTDATFS)及其与乙酸镍、乙酸钴、乙酸铜、乙酸锌等金属盐鏊合的金属鏊合物。通过红外光谱、紫外-可见吸收光谱和MALDI质谱等对染料及其金属鏊合物进行了结构表征;使用旋涂方法在K9玻璃和抛光的单晶硅基片上制备薄膜;研究了镍金属鏊合物的热学性能;使用椭偏仪研究了Ni和Zn鏊合物的光学常数。结果表明:4种金属鏊合物薄膜最大吸收光谱为621-629nm,且长波边吸收峰陡峭;TGA-DSC测试结果表明镍金属鏊