Laser wavelength effect on structural and optical properties of Cd34Se66 nanocrystalline thin film

Cadmium Selenide (Cd₃₄Se₆₆) thin films are deposited on a glass substrate using the thermal evaporation method at room temperature. The Cd₃₄Se₆₆ films are characterized using XRD. The crystallite size of the film is calculated from XRD data, which is found as 29.61 nm as-deposited. It is also found that crystallite size of Cd₃₄Se₆₆ changed after irradiation with N₂ and Nd:YAG laser. The changes in the optical properties of the films after irradiation with N₂ laser and Nd:YAG laser are also studied in the wavelength range of 300-700 nm and it is found that the optical band gap of the Cd₃₄Se₆₆ films changed after laser irradiation.     

Microanalysis of blue pigments from the Ptolemaic temple of Hathor (Thebes), Upper Egypt: a case study

The aim of the present work was to characterize blue pigment samples collected from the Ptolemaic temple of Hathor (Thebes), the western bank of Luxor, Upper Egypt. The characterization of the examined pigments was carried out by means of optical microscopy, scanning electron microscopy equipped with an energy dispersive X‐ray detector, micro X‐ray fluorescence spectrometry and Fourier transform infrared spectroscopy. On the basis of the chemical composition and microstructure of the samples, the blue pigments were identified as Egyptian blue (cuprorivaite, CaCuSi₄O₁₀). Moreover, the micro X‐ray fluorescence analysis revealed significant quantities of lead in the glass phase suggesting that a leaded bronze scrap was used to produce the pigment. The optical examination of the paint layers showed that the pigments were applied on a thin layer consisting of gypsum (CaSO₄?2H₂O) and dolomite (CaMg(CO₃)₂). In addition, some pigment samples showed discoloration mainly in the form of green and black hues. The obtained results helped in improving our knowledge about some painting materials used during the Ptolemaic era of ancient Egypt. Copyright © 2012 John Wiley & Sons, Ltd.     

Microfluidic chip fabrication using hot embossing and thermal bonding of COP

The application of silicon mold inserts by micro‐hot embossing molding has been explored in microfluidic chip fabrication. For the mold insert, this study employed an SU‐8 photoresist to coat the silicon wafer. Ultraviolet light was then used to expose the pattern on the SU‐8 photoresist surface. This study replicates the microstructure of the silicon mold insert by micro‐hot embossing molding. Different processing parameters (embossing temperature, embossing pressure, embossing time, and de‐molding temperature) for the cycle‐olefin polymer (COP) film of microfluidic chips are evaluated. The results showed that the most important parameter for replication of molded microfluidic chip is embossing temperature. De‐molding temperature is the most important parameter for surface roughness of the molded microfluidic chip. The microchannel is bonded with a cover by thermal bonding processing to form the sealed microfluidic chip. The bonding temperature is the most important factor in the bonding strength of the sealed microfluidic chip. Copyright © 2009 John Wiley & Sons, Ltd.     

Interaction of “extremely diluted solutions” with aqueous solutions of hydrochloric acid and sodium hydroxide: A calorimetric study at 298 K

The “extremely diluted solutions” (EDS) have revealed a really intriguing behaviour, characterized by multiple independent variables. Because of their behaviour, EDS can be described as far-from-equilibrium systems, capable of auto-organizing as a consequence of little perturbations.

We measured the heats of mixing of basic and acid solutions with such EDS and their electrical conductivity, comparing with the analogous heats of mixing and electrical conductivity of the untreated solvent.

In particular, calorimetric titrations have been performed with NaOH or HCl solutions at various concentrations. Plots of the excess heat as a function of the concentration of titrant reveal differences and similarities between the two. By analysing these plots we were able to formulate new hypotheses about the supramolecular organization of the solvent water, when subject to mechanical perturbations stemming from the EDS preparation protocol, that is comprised of an iterative process of successive dilutions and succussions.     

白云鄂博天然钕独居石的振动光谱研究(英文)

Raman, infrared and energy dispersive X-ray spectra of monazites have been measured and discussed. The result shows that the mineral is enriched in cerium, lanthanum,neodymium and praseodymium (Ce＞La＞Nd＞Pr)， The monazites have marked spectral characteristics, especially their v1, V3 Raman bands and v1, v4 infrared absorption bands. The characteristics can distinguish between monazite and other phosphate minerals. In addition, based on EDS and infrared absorption spectra, a small amount of fluoro-carbonate is found in the monazites.     

Degradation profiles in aged EPDM water seals using focused ion beam-scanning electron microscopy

The degradation of an ethylene–propylene-diene (EPDM) rubber seal used in a water supply system was investigated using focused ion beam-scanning electron microscopy (FIB-SEM). The EPDM rubber seal was used for 3 years within the temperature range 20–40 °C in a city water system. The accretions present on the surface of the EPDM seal after use were observed by SEM and were found to consist of iron and oxygen atoms based on energy dispersive X-ray spectroscopy (EDS) analysis. A cross-sectional depth image of the EPDM rubber was obtained by FIB-SEM, after slicing the EPDM rubber with a focused Gallium ion beam. Iron and oxygen atoms in the cross-section of the EPDM rubber were detected through EDS. The distribution of iron was comparable to that of oxygen derived from the carbonyl groups generated by the degradation of EPDM, suggesting that iron ions may promote the degradation of natural rubber through catalytic effects.     

矿物药蒙脱石散EDS指纹图谱双指标等级序列个性化模式识别分析及快速质量评价

矿物药中的多种金属和非金属元素及其含量决定了其功效。目前亟待建立普遍适用的、非化学分析的、以元素种类及其含量信息为基础的多种矿物药快速鉴别及定量质量评价方法。EDS元素指纹图谱可以快速测定各类矿物药的元素种类及含量。双指标等级序列个性化模式识别法则通过比较计算任意两个样品的共有(量)指标率及变异(量)指标率,建立以各个样品为参考的个性化双指标序列,然后再计算每个序列中所有样品的平均共有指标率及其标准偏差S,构造相似尺度函数P≥+xS。确定适合于所有样品最优分类的x和每个样品的个性化的显著相似样品特征序列,将其作为分类标准实现最佳分类。该法不仅适用于仅有共有峰,同时也适用于既存共有峰又有变异峰的指纹图谱的量化分析。测定了七种不同公司生产的蒙脱石散的EDS指纹图谱,计算了不同样品指纹图谱之间峰面积(或主要活性元素Fe,Al,Ca,Mg,Si的含量)的双指标率,当相似尺度x=0.5,可对七种蒙脱石散产品进行高分辨鉴别及准确质量评价。该法为矿物药的快速高分辨鉴别及定量质量评价提供了一种新途径。     

Combined analysis methods for investigating titanium and nickel surface contamination after plasma deep etching

Plasma etching techniques can result in damage and contamination of materials, which, if not removed, can interfere with further processing. Therefore, characterisation of the etched surface is necessary to understand the basic mechanisms involved in the etching process and enable process control and cleaning procedures to be developed. A detailed investigation by means of the combined use of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDS), X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM) has been carried out on deep titanium trenches etched by plasma. This innovative approach has provided a further insight into the microchemical structure of the surface contamination layer on both the titanium and the nickel hard mask surfaces. The described experiments were conducted on 25 to 100-μm wide trenches, first etched in bulk titanium by an optimised Cl₂/SF₆/O₂-based inductively coupled plasma process, through an electroplated nickel hard mask. The results allow to identify chlorine, fluorine and carbon as the main contaminating agents of the nickel mask and to associate three oxidation states around the etched trenches highlighting certain specific aspects related to the passivation mechanism. These observations reinforce the scientific relevance of the combined use of complementary optical and imaging analytical techniques.     

Characterization of carbon nanotubes and analytical methods for their determination in environmental and biological samples: A review

In the present paper, a critical overview of the most commonly used techniques for the characterization and the determination of carbon nanotubes (CNTs) is given on the basis of 170 references (2000–2014). The analytical techniques used for CNT characterization (including microscopic and diffraction, spectroscopic, thermal and separation techniques) are classified, described, and illustrated with applied examples. Furthermore, the performance of sampling procedures as well as the available methods for the determination of CNTs in real biological and environmental samples are reviewed and discussed according to their analytical characteristics. In addition, future trends and perspectives in this field of work are critically presented.     

貉被毛的电镜观察和X射线能谱分析

本文对貉被毛的形态结构进行了扫描电镜观察,并且利用Ｘ射线能谱仪分别对鳞片层、皮质层和髓层进行了元素分析。结果表明：不同科属动的毛纤维其结构和元素成分存在差异。可为动物纤维的性能研究,鉴别及动物分类提供依据。