Raman spectroscopy of melamine‐formaldehyde resin microparticles exposed to processing in complex plasma

We explore the characterization of melamine formaldehyde resin (MF‐R) micron‐sized particles, immersed in argon, neon and argon–oxygen plasmas, using Raman spectroscopy. It is shown that plasma treatment of MF‐R results in modification of its chemical composition. Particularly, a decrease in the intensities of the Raman scattering bands, corresponding to both formaldehyde C―H and melamine C―N and N―H bonds, is observed. The band at 980–990 cm⁻¹, associated with breathing vibrations of the triazine rings, undergoes the most significant changes, and the greatest modifications of the spectra are observed after exposure to Ar and Ar–O₂ plasma, whilst for the MF‐R particles exposed to Ne plasma these modifications are less pronounced. Copyright © 2016 John Wiley & Sons, Ltd.     

Recent progress in all-inorganic metal halide nanostructured perovskites: Materials design,optical properties,and application

Low-dimensional all-inorganic metal halide perovskite (AIMHP) materials, as a new class of nanomaterials, hold great promise for various optoelectronic devices. In the past few years, tremendous progress has been achieved in the development of efficient and stable AIMHP nanomaterials for optical property studies and related applications. Here, we offer a critical overview on the unique merits and the state-of-the-art design of AIMHP using different composition strategies. Then, the effects of material compositions, dimensionality, morphologies and structures on optical properties are summarized. We also comprehensively present recent advances in the development AIMHP nanomaterials for practical applications including solar cells, light-emitting diodes, lasers and photodetectors. Lastly, the critical challenges and future opportunities in this emerging field are highlighted.     

Ab-initio calculations of bandgap tuning of In1-xGaxY (Y = N,P) alloys for optoelectronic applications

The Ⅲ-V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few decades. In the present article, the bandgap tuning and its influence on optical properties of In_1-xGa_xN/P, where (x = 0.0, 0.25, 0.50, 0.75, and 1.0) alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method (FP-LAPW) and modified Becke and Johnson potentials (TB-mBJ). The direct bandgaps turn from 0.7 eV to 3.44 eV, and 1.41 eV to 2.32 eV for In_1-xGa_xN/P alloys, which increases their potentials for optoelectronic devices. The optical properties are discussed such as dielectric constants, refraction, absorption, optical conductivity, and reflection. The light is polarized in the low energy region with minimum reflection. The absorption and optical conduction are maxima in the visible region, and they are shifted into the ultraviolet region by Ga doping. Moreover, static dielectric constant ε₁(0) is in line with the bandgap from Penn's model.     

碳纳米管的力学

在发现碳纳米管后不久,对于这些有趣结构的力学性质--包括高强度、高硬度、低密度和结构的完美性的理论预测,使人们认识到它们可能具有理想的科技应用价值.对这些预测的实验验证或个别验伪以及大量基于不同模型的计算机模拟方法,使得逾10年来对碳纳米管力学的理解日趋深入但远未达到尽头.本文回顾了理论预测,并对这种微小结构的观察和操作中经常用到的富有挑战性的实验技术进行了讨论.略述了采用的计算方法包括从头算法量子力学模拟、经典分子动力学和连续介质模型.多尺度和多物理模型的发展和模拟工具自然而然作为连接基础科学问题和工程应用的结果而出现,而这个主题仍然正在抓紧研究中.这里介绍了研究此主题的一些方法.注意力主要集中于研究力学性质的揭示方面,如杨氏模量、弯曲刚度、屈曲准则、拉伸和压缩强度.最后,讨论了利用这些性质的几个令人兴奋的应用例子,包括纳米绳束、填充的纳米管、纳米机电系统、纳米传感器和纳米管增强复合材料,引用了349篇参考文献. 图41参349     

Plasma nanoscience: from nano-solids in plasmas to nano-plasmas in solids

The unique plasma-specific features and physical phenomena in the organization of nanoscale soild-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter to nano-plasma effects and nano-plasmas of different states of matter.     

Untersuchungen zur Stabilität 131J-markierten Inulins in vivo

Nach Entwicklung eines ¹³¹J-markierten J-J-Propylinulins von ausreichender Reinheit und Lagerungsstabilität wurde die Stabilität des Präparates in vivo geprüft. Bei 14 untersuchten Patienten fand sich mit einer statischen Sicherheit von 90% eine Abspaltung von freiem ¹³¹J aus der Verbindung bereits 2 h p.i., so daβ die Anwendung des Präparates für Clearance-und Inulinraumbestimmungen derziet nicht empfehlenswert erscheint.     

Magnetofection: Magic magnetic nanoparticles for efficient gene delivery

Magnetic nanoparticles (MNPs) have become a research hotspot and widely used in the biomedical field in recent decades due to their unique magnetic properties. This minireview summarizes the specific gene transfection of magnetic particles (magnetofection) during eversy dynamic process of gene delivery (gene binding, cellular uptake, endosomal escape, intracellular trafficking and in vivo targeting). Meanwhile, the synergistic biomedical application of magnetofection and the effects of MNPs have also been discussed, including magnetic resonance imaging (MRI), magnetic mediated hyperthermia (MMH), Fenton reaction and autophagy. Finally, the clinical prospect of magnetofection was briefly expected.     

多自由度超声电机的研究现状与展望

多自由度超声电机是将两种以上的超声振动模式按照一定的方式组合,通过在定子的表面产生椭圆运动来实现转子的多自由度转动.文中综述了近年来发展起来的几种多自由度超声电机的结构、工作原理和特征,并就多自由度超声电机的工程应用和未来发展方向进行了展望.     

石墨烯与太赫兹科学

石墨烯（Graphene）是材料科学和物理科学领域一颗冉冉升起的新星.作为一种具有优异晶体品质和电子性质的二维材料,石墨烯表现出独特的电子输运、光学耦合、电磁学和其他新奇的性质.例如,石墨烯的禁带宽度和有效质量为零,其电子和空穴的运动方式与相对论性粒子相同.另外,石墨烯拥有已知材料中最高的迁移率,且其迁移率基本与温度无关.石墨烯具有众多的新颖物理现象和应用潜能,其中在太赫兹科学上的应用前景尤其广阔.石墨烯的等离子振荡、可外部控制的导电率及可人为调谐的禁带宽度都与太赫兹科学息息相关.文章重点地介绍了石墨烯的     

激光50华诞

2010年是激光诞生50周年.文章回忆了激光发明的历史沿革,简要讨论了受激光发射的物理模型、激光的特性,详细回顾了激光发明后50年间激光器件、技术、应用和产业的发展大事记,介绍了对激光和光电子学作出重大贡献的先驱和科学家,并对一些相关学科和重要应用做了概述.