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71.
以含氟醇钾盐(NFHO-K )作为引发剂,通过阴离子活性聚合方法合成了氟烷基封端的聚甲基丙烯酸-2-(二甲氨基)乙酯-block-聚甲基丙烯酸-2-(二乙氨基)乙酯嵌段共聚物(NFHO-PDMA-b-PDEA).该共聚物与一般的含氟嵌段共聚物相比,既具有优良的表面活性,又具有较好的溶解性.通过对溶液表面张力的测定,荧光探针法对溶液临界聚集浓度(cac)的测定和透射电子显微镜(TEM)对共聚物在溶液中胶束形态的研究,发现无机盐对共聚物在水溶液中的聚集行为有明显的影响,并可以增强共聚物的表面活性. 相似文献
72.
在竞争激烈的移动支付市场中,对客户进行细分尤为重要。从客户的心理、态度等角度出发,首先采用MaxDiff调查方法测量受访者对移动支付产品的偏好,从而得到MaxDiff数据,再利用潜在类别分析对客户进行分类得到每个细分群体在各个对象上的偏好得分,最后从人口统计学和行为特征方面对细分群体进行验证分析。研究结果显示:客户被分成3个细分群体,分别是"安全和场景"类、"优惠和便捷"类以及"功能和速度"类,它们在移动支付的偏好上有显著差异。这样的细分结果可为移动支付服务商实施精准营销提供决策参考。 相似文献
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75.
Zero dispersion wavelength and dispersion slope control of hollow-core photonic bandgap fibres 下载免费PDF全文
This paper investigates the zero dispersion wavelength and
dispersion slope control of hollow-core photonic bandgap fibres
(PBGFs) by using a full-vector finite element method. By simulation
we found that theoretically the zero dispersion wavelength can be
tailored by respectively changing the rounded diameter of air holes,
pitch, refractive index, normalized thickness of core rings, and
hole diameter to pitch ratio. At the same time the tailoring of
dispersion slope can also be realized by changing the rounded diameter
of air holes or pitch or normalized thickness of core rings. To
illustrate the reasonability of fibre designs, this paper also gives
the variance of normalized interface field intensity which measures
the scattering loss relatively versus wavelength for different
designs. From the viewpoint of loss, varying the rounded diameter
and the thickness of core ring could shift zero wavelength but it is
difficult to get the required parameters within so tiny range in
practical drawing of PBGFs, on the other hand, it is possible in
practice to respectively alter the pitch and refractive index to
shift zero wavelength. But varying hole diameter to pitch ratio is
not worthwhile because they each induce large increase of loss and
narrowness of transmission bandwidth. The zero dispersion wavelength
can be engineered by respectively varying the rounded diameter of air
holes, pitch, refractive index, and normalized thickness of core
rings without incurring large loss penalties. 相似文献
76.
从化学分离手段的改进、后处理的对象变化、与分离功能的拓展等方面较为系统地阐述了核燃料后处理技术发展过程及技术特点;以先进核能系统中分离嬗变为目标,概括总结了从第二代后处理技术向第三代和第四代后处理技术发展过程中Purex流程、后续的分离工艺与处理快堆元件的干法后处理工艺中的主要放射化学问题。 相似文献
77.
赣南萤石矿床地下水金属离子分布特征及形成机理 总被引:1,自引:1,他引:0
利用原子吸收光谱对赣南新塘萤石矿区矿井下渗水的阳离子进行测试,分析发现其主要阳离子沿矿井垂直深度分布差异悬殊,其中Na+、Ca2+含量最高,同时Ca2+、Na+、K+、Mg2+均随垂直深度而递增.在矿井垂直深度50、100、150 m,Ca2+、Na+、K+、Mg2+主要阳离子含量成倍递增,其中Ca2+含量高于CaF2在水中的溶解度11~33倍,这种变化指示矿井下渗水主要阳离子并非来自对萤石矿的溶蚀.相关性分析显示,Ca2、Na+、K+、Mg2+阳离子之间均有良好的相关性,高钠盐含量表明矿井下渗水对围岩的溶蚀作用是溶解物质的主要来源,水体主要阳离子浓度随路径增加而增大. 相似文献
78.
The compound diffractive telescope is a novel space optical
system which combines the structure of compound eyes with
diffractive optics and so it has a lighter weight, a wider field of
view (FOV), a lower cost as well as looser fabrication tolerance. In
this paper, the design of a compound diffractive telescope
composed of one primary lens and twenty-one eyepieces is
introduced. Then the influence of diffraction orders on the
performance of the system is analysed. A modified phase function
model of diffractive optics is proposed to analyse the modulation
transfer function (MTF) curves for 0℃ FOV, which provides a
more accurate prediction of the performance of the system. In
addition, an optimized mechanism is also proposed to suppress stray
light. The star image and resolution tests show that the system can
achieve diffraction limit imaging within ± 2℃ of FOV and
±4~mm of eccentricity. Finally, a series of pictures of an object
are taken from different channels, and the splicing of pictures from
adjacent FOVs is demonstrated. In summary, the designed system has
been proved to have great potential applications. 相似文献
80.