牛奶全氮检测方案

文献名： Structural, morphological and optical properties of Bi NPs obtained by laser ablation and their selective detection of L-cysteine 作者： Ramon Gabriel Teixeira Rosaa, Celso de Araujo Duartea , Wido Herwig Schreinera, Ney Pereira Mattoso Filhoa, Arandi Ginane Bezerra Jr.b, Andersson Barisonc, Fernanda Maria Marins Ocamposc a Departamento de Física, Universidade Federal do Paraná Centro Politécnico, CP 19044, 81531-990 Curitiba (PR), Brazil b Departamento Acadêmico de Física, Universidade Tecnológica Federal do Paraná, 80230-901 Curitiba (PR), Brazil c Departamento de Química, Universidade Federal do Paraná Centro Politécnico, CP 19081, 81531-990 Curitiba (PR), Brazil 摘要：In the present work we show the results of the investigation of the properties of bismuth nanoparticles (NPs) obtained by the laser ablation in water. The samples were characterized by various techniques: UV/vis spectroscopy, dynamic light scattering, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, nuclear magnetic resonance and zeta potential. The NPs were metallic and surface oxidated, exhibiting absorption peak at 257 nm due to the surface plasmon resonance. The interaction between the NPs and various amino acids was studied and revealed a selective sensibility to cysteine on a range of concentration from 80 to 720 μM, which we attribute to a dimerization of cysteine to cystine probably complexed to the nanoparticle surface by electrostatic interactions, leading to the modification of the NP absorption spectrum. 关键词：Bismuth; Nanoparticles; Laser ablation; Cysteine

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PCB、连接器和半导体等电子元件利用镀层来保护铜表面并提供良好的电接触。国际一流的IPC标准规范涵盖了PCB电镀镀层厚度结构，此类结构具有精确的镀层（包含若干层）厚度，以确保成品元件在器件的预期使用寿命内发挥应有的性能。 磁感应测厚仪可以快速、可靠地测量PCB上的铜层厚度，而台式XRF是测量金、镍、锡、银和钯镀层的首选技术，此类镀层形成了关键部件的电镀接触并保护底层的铜层。当前，在电子元件尺寸和复杂性方面面临着诸多挑战，因此，为该类应用领域选择的镀层厚度测量设备必须专门适用于测量电子元件。

蔗糖和工业用糖的表观纯度解决方案