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51.
Jinlian Hu Bipin Kumar Harishkumar Narayana 《Journal of Polymer Science.Polymer Physics》2015,53(13):893-898
Like shape memory polymers, a novel phenomenon of stress memory was shown in which the stress of a material can respond to an external stimulus. This concept was further enlightened by a switch‐spring‐frame model that would eliminate the limitation of existing models which overlooked the stimulus responsive nature of such polymers. The discovery being reported in this article was stemmed from a real case study into shape memory polymer fibers in compression stocking for varicose veins. The breakthrough of stress memory enabled researchers to develop applications needing stimuli‐responsive forces, which can broaden the horizon of such smart polymers in emerging smart products in many multidisciplinary fields such as sensors, stress garments, and massage devices, electronic skins, and artificial muscles. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 893–898 相似文献
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铁离子和硫氰化钾反应生成稳定的血红色络合物硫氰化铁,用智能手机拍摄所得图像的颜色反映在图像的RGB值上。随着该溶液浓度的增大,溶液颜色逐渐加深,反映在拍摄的图像中颜色的RGB值也在变化,并且得出该溶液颜色的R值与溶液的浓度成线性关系。结果显示,用该实验方法测得的抗贫血药物中铁的含量与用紫外分光光度法测得同一药品中铁的含量相比误差为5%;并且该实验方法在中学的化学实验课中很容易实现,避免了学生用目视比色法测量抗贫血药物中铁的含量时因标准溶液的色阶选择不合适而导致实验的失败。 相似文献
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Laser-induced breakdown spectroscopy (LIBS) was applied to the preliminary examination of Polish documents – passports and identity cards – for forensic purposes. Several security features of potentially high discrimination capability were selected at both the passports (Alphagram, serial number, the contour map of Europe, and emblem) and identity cards (kinegram, the date of birth, and emblem). Different elemental compositions were identified after comparing the spectra recorded from various measurement locations. It was possible to identify characteristic atomic emission from several elements (such as Ti, Ca, K, Fe, Cr, Mg, Na, La, Cd, Li, V, Al, Mn, Ni, and Cu) based on the type of document, issue date, and evaluated area. In the case of passports, the potentially good discriminators with unique elemental composition were identified, e.g., the serial number and the contour map of Europe printed with the use of intaglio printing technique. Identity cards with the cover of polycarbonate foil constitute a very difficult sample to analyze because of the foil’s influence on the laser ablation phenomenon. This study presents the potential of LIBS as an effective and useful technique to analyze Polish passports for forensic purposes. Its many advantages provide a good alternative to the analytical methods routinely used for the examination of these objects. 相似文献
55.
Zhuang Liu Yousef Faraj Xiao-Jie Ju Wei Wang Rui Xie Liang-Yin Chu 《Journal of polymer science. Part A, Polymer chemistry》2018,56(19):1306-1313
Responsive hydrogels have the ability to change their volume, transparency, or other properties in response to external chemical and/or physical stimuli. The responsiveness properties including responsive rate and degree, as well as mechanical properties such as Young's modulus, toughness, breaking strength, and breaking strain are crucial parameters of the smart hydrogels that determine the scope of hydrogel applications such as soft actuators, artificial muscles, and tissue engineering scaffolds. In this paper, the development of the nanocomposite smart hydrogels, which can achieve both improved responsiveness and mechanical properties, is reviewed. First, the fabrication approaches for building the nanocomposite networks by doping organic or inorganic nanomaterials via crosslinking or blending strategies are introduced. Then, the mechanisms used to improve both responsiveness and mechanical properties of nanocomposite responsive hydrogels are discussed. Finally, the perspectives as well as current challenges of such nanocomposite responsive hydrogels are addressed. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1306–1313 相似文献
56.
ABSTRACTThe connected home is a critical part of the network—but one that has seen little in the way of true investment in recent years. With customer loyalty and churn directly linked to quality of experience, this is a part of the network that no players in the supply chain can afford to ignore any longer. Beyond broadband experience, the addition of smart technology to the connected home also represents one of the biggest revenue growth areas in the consumer telecoms market for some time. From both a churn-reduction and a revenue-growth perspective, investment in the connected home network must accelerate. This article outlines the key trends identified by Ovum in the connected home space for 2016 and beyond. 相似文献
57.
针对具有高可靠、长寿命特点的智能电能表,应用加速退化试验方法进行可靠性评估是一种有效的方法。开展加速退化试验过程中,在高加速应力激发下,一方面可观测到智能电能表的性能退化,也可能出现智能电能表的整表失效。如何融合智能电能表加速寿命试验过程中的整表失效数据、性能退化数据转化得到的伪寿命数据,从而进行智能电能表的综合可靠性评估,是智能电能表可靠性评估急需解决的问题。本文研究提出基于贝叶斯方法的智能电能表可靠性评估方法,给出融合智能电能表的整表失效数据、伪寿命数据的数据处理方法及计算模型,探讨了伪失效数据计算方法、整表失效数据与伪失效寿命数据相容性检验方法等。 相似文献
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Schistosomiasis is one of the major public health problems worldwide. Even though this is a common illness among preschool children in poor countries, treatment is carried out mainly through the administration of praziquantel tablets, which has some disadvantages, such as the strong bitter taste. As an alternative to overcome this problem, the development of new encapsulated praziquantel formulations is demanded. For this reason, suspension polymerizations are carried out for the in situ encapsulation of praziquantel into polymer microparticles, using methyl methacrylate (MMA) and cationic compounds (diethylaminoethyl methacrylate, DEAEMA, and dimethylaminoethyl methacrylate, DMAEMA) as comonomers. This technique allows for the preparation of polymer microparticles with high encapsulation efficiencies (>90%) with characteristic sizes ranging from 0.5 to 1500 µm. Drug release profiles show that praziquantel is released from poly(methyl methacrylate) microparticles slowly due to the existence of strong diffusional resistance. On the other hand, the addition of cationic comonomers renders polymer particles sensitive to pH variations, allowing for faster release of praziquantel in acidic environments, as found in the stomach. 相似文献
60.
介绍了一种利用普通智能手机和一根两端开口奶茶管基于声驻波现象来测量声速的方法。这种实验方法所用的实验仪器随手可得,无需学生再到学校的实验室进行实验,激发了学生的学习兴趣,增强了学生的动手能力。 相似文献