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1INTRODUCTION Atom transfer radical addition is an efficient me-thod for carbon-carbon bond formation in organic synthesis[1,2].In some of these reactions,a transi-tion-metal catalyst acts as a carrier of the halogen atom in a reversible redox process.The transition-metal-catalyzed has been successfully used to con-trol radical polymerization[3].In the process,the transition-metal species initially abstracts halogen atom X from organic halide to form oxidized species and carbon-centered r… 相似文献
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基于PZT压电陶瓷驱动器的非球面能动抛光盘,能够在PZT驱动器的作用下改变面形,用于中小口径非球面镜加工。为优化设计基于PZT压电陶瓷驱动器的非球面能动抛光盘,利用有限元分析方法,计算各驱动器的影响函数,计算非球面能动抛光盘的输出面形,与理论面形比较得到剩余残差。以优化设计驱动器排布方式和极头直径为例,当非球面能动抛光盘中心到非球面工件中心的距离L为120mm,分别计算比较,极头直径为Φ10mm时,19单元PZT圆形排布与21单元PZT方形排布的剩余残差;以及19单元PZT圆形排布时,极头直径为Φ10mm与Φ14mm的剩余残差。结果表明,非球面能动抛光盘产生变形后的剩余残差RMS相应分别为0.303μm、0.367μm、0.328μm。因此,基于PZT压电陶瓷驱动器的非球面能动抛光盘确定选用19单元PZT圆形排布且极头直径Φ10mm。 相似文献
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在室温和10 Pa氩气环境中,引入平行于靶面方向的直流电场,通过改变脉冲激光能量密度烧蚀单晶硅靶,在与羽辉轴线呈不同角度的衬底上沉积纳米硅晶薄膜。利用扫描电子显微镜和拉曼散射谱对沉积样品进行分析,结果表明:随着激光能量密度的增加,位于相同角度衬底上的晶粒尺寸和面密度逐渐变大;在同一激光能量密度下,零度角处衬底上的晶粒尺寸和面密度最大,且靠近接地极板处的值比与之对称角度处略大。通过朗缪尔探针对不同能量密度下烧蚀羽辉中硅离子密度变化的诊断、结合成核区内晶粒成核生长动力学过程,对晶粒分布特性进行了分析。 相似文献
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The spectroscopic data recorded by dispersion spectrophotometer are usually degraded by the response function of the instrument. To improve the resolving power, double or triple cascade spectrophotometer and narrow slits have been employed, but the total flux of the radiation decreases accordingly, resulting in a lower signal-to-noise ratio (SNR) and a longer measuring time. However, the spectral resolution can be improved by mathematically removing the effect of the instrument response function. Based on the Shalvi-Weinstein criterion, a Gauss-Newton based kurtosis blind deconvolution algorithm for spectroscopic data is proposed. Experiments with some real measured Raman spectroscopic data show that this algorithm has excellent deconvolution capability. 相似文献
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为了提高飞轮与整星耦合特性影响成像像移理论预估的精度,提出了一种星上飞轮安装刚度和阻尼参数的数值补偿算法.首先,建立补偿算法数学模型,基于飞轮径向摇摆模态以及线性整星微振动传递函数模型,通过联合飞轮在专用测量平台上的扰振实测数据以及星上安装后所致成像像移实测数据构建优化函数,实现对星上飞轮安装刚度以及阻尼参数的补偿.其次,采用该算法对某型号卫星上的飞轮安装刚度以及阻尼进行了补偿和估计,最后对参数补偿前后的飞轮扰振所致像移分别进行理论预估与对比.对比结果表明:参数补偿后的预估像移数据较补偿前预估像移数据更接近实测像移数据且径向摇摆模态固有频率曲线更加明显,证明此参数补偿算法可行.本研究显著降低了整星微振动分析过程中飞轮在星上安装刚度与测试平台安装刚度不一致所带来的分析误差,为飞轮与整星耦合特性安装等效参数求解提供了一种思路. 相似文献
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The spectra recorded by dispersion spectrophotometerare usually distorted by the response function of the in-strument. These distortions generally include the over-lapping of adjacent peaks and the aberrancy of the rel-ative intensities among the peaks. The major factor ofthe instrument response function limiting the resolvingpower is the slit width and the diffractive limit of thedispersive grating. To improve the resolving power, dou-ble or triple cascade spectrophotometer, narrow slits have… 相似文献