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Katsuyuki Yoshikawa 《Proceedings of the American Mathematical Society》1998,126(12):3727-3731
We consider the order of a meridian (of the group) of a Klein bottle smoothly embedded in the -sphere . The order of a meridian of a Klein bottle in is a non-negative even integer. Conversely, we prove that, for every non-negative even integer , there exists a Klein bottle in whose meridian has order .
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模拟啤酒瓶污垢,采用与啤酒瓶材质相同的玻片,用白度值反映玻征污染前后及洗涤前后透光率的变化,研究出一种啤酒瓶清洗剂去污力评价方法。用该法在实验室通过去污力测试比较进行啤酒瓶清洗剂品配方的选择与调整是可行的,试制的产品完全达到实洗效果的要求。 相似文献
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衍射理论对局域空心光束及无衍射光束重建的描述 总被引:13,自引:5,他引:8
利用衍射理论导出了局域空心光束的传输表达式及光强分布,给出了局域空心光束的精细结构,详细分析了其演变过程。讨论了聚焦透镜的焦距f对径向暗域最大尺寸及轴上暗域长度的影响。结果表明,径向暗域最大尺寸及轴上暗域长度都随着f的增大而增大。通过轴棱锥-透镜系统获得局域空心光束,用体视显微镜和CCD照相机组成的系统拍摄光束强度分布。结果表明应用衍射理论可以较精确地描述局域空心光束的演变过程。找出了其应用中的不利因素,更清晰地展现无衍射光束的重建现象。这种描述方法弥补了几何理论和干涉理论的不足。 相似文献
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相干贝塞尔光产生具有塔尔博特效应的局域空心光束 总被引:10,自引:3,他引:7
提出一种由轴棱锥产生的贝塞尔光干涉整形得到具有自成像塔尔博特效应的近似无衍射局域空心光束的新方法。详细分析了两束相干同频率贝塞尔光的相互作用原理及其如何控制局域空心光束的空间尺寸。数值模拟了干涉叠加后光场沿传输距离变化的光强分布及一个完整周期内光强的演变和局域空心光束的形成过程,给出了相干贝塞尔光产生局域空心光束的个数及局域空心光束最大无衍射距离的表达式。 相似文献
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用计算机模拟的方法研究了地磁场中带电粒子的运动特性,绘制了粒子轨迹曲线,对粒子运动进行了分析,解释了地磁场的磁瓶效应和辐射带. 相似文献
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Adulteration of pharmaceutical packaging containers with postconsumer recycled plastic materials was considerably difficult to identify due to the similar chemical compositions of virgin and recycled plastics. In the present study, near-infrared (NIR) spectroscopy coupled with conformity test was proposed to screen the adulteration of pharmaceutical packaging containers. Two kinds of representative screening models were investigated on polypropylene (PP) bottles for oral drug package. The reliability of the screening models was validated through studying the identification reliability, specificity, and robustness of the methods. The minimum spiking level of two modeled adulterants at the proportion of 20% could be detected, and the unqualified sample from a domestic manufacturer was rejected by this developed method. This strategy represents a rapid and promising analytical method for screening the adulteration of pharmaceutical plastic packaging containers with postconsumer recycled plastics. 相似文献
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Chemical depolymerization of poly(ethylene terephthalate) (PET) waste is a possible remedy to huge amount of solid waste generation as it results in degradation products that possess a potential of recyclability. PET bottle waste was depolymerized by aminolysis using diethanolamine. Novel synthesis of N1, N1,N4,N4-tetrakis (2-hydroxyethyl) terephthalamide (THETA) with 73-76% yield and terephthalic acid (TPA) with 78-82% yield was achieved. The purified products were analyzed by FTIR, melting point, DSC, DTG and 1H-NMR. THETA has various applications in the synthesis of rigid polyurethane foam, unsaturated polyester resins and also as a cross linking agent/ hardener for epoxy resins. 相似文献
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提出一种利用相位连续可调诱导产生的双艾里光束形成方形光瓶的方法。该方法首先利用二值化后的相位调制出双艾里光束,为了能够实现光瓶能量分布,一个可调控的线性因子被引入到相位调制函数中形成新改进的相位,该相位能够灵活地调节光瓶的大小。数值模拟结果表明高斯光束通过该改进相位调制,能够形成光瓶能量分布的光束。该方形光瓶光束可应用于光镊、原子捕获与操纵。 相似文献