Structural and optical properties of Co-doped NiO films prepared by SILAR method

In this study, transparent thin films of un-doped and Co-doped nickel oxide were deposited onto microscopic glass substrates using the successive ionic layer adsorption and reaction (SILAR) method. The effect of cobalt doping on structural, morphological and optical properties was investigated. XRD studies reveal that all the films are polycrystalline with cubic structure and exhibit (1 1 1) and (2 2 2) preferential orientations. Co is well incorporated in the host lattice without altering the structure. All films retain high transparency throughout the visible spectral regime. No significant shift in Raman spectra was observed due to the Co doping.     

Reaction mechanism of CO methanation on nickel catalysts,as studied by isotopic and nonstationary methods

Kinetic isotope effects were measured upon the replacement of hydrogen by deuterium in the reaction of carbon monoxide methanation on nickel catalysts supported on TiO₂ and γ-Al₂O₃. Data on the mechanism of the process were obtained with the use of a nonstationary method. A step-scheme was proposed, in which the interaction of oxygen-containing compounds with hydrogen is a slow step of the process.     

Visualizations of the flow around a swimmer in turbulent regime

Graphical abstract  

     

Magnetic and magneto-optical properties of FeRh thin films

The magnetic and magneto-optical properties of FeRh thin films epitaxially deposited onto MgO(1 0 0) substrates by RF sputter-deposition system have been investigated in conjunction with the structure. An intriguing virgin effect has been found in the M–T curves of the as-deposited FeRh thin films, which is presumably interpreted in term of a change in structural phase when heating. Also, a (negative) maximum peak of Kerr rotation at around 3.8 eV has been observed when FeRh thin films are in ferromagnetic state. The polar Kerr rotation angle is found to increase at temperatures above 100 °C, which corresponds to the antiferromagnet (AF)–ferromagnet (FM) transition of FeRh thin films.     

Observation of synchrotron radiation from electrons accelerated in a petawatt-laser-generated plasma cavity

The dynamics of plasma electrons in the focus of a petawatt laser beam are studied via measurements of their x-ray synchrotron radiation. With increasing laser intensity, a forward directed beam of x rays extending to 50 keV is observed. The measured x rays are well described in the synchrotron asymptotic limit of electrons oscillating in a plasma channel. The critical energy of the measured synchrotron spectrum is found to scale as the Maxwellian temperature of the simultaneously measured electron spectra. At low laser intensity transverse oscillations are negligible as the electrons are predominantly accelerated axially by the laser generated wakefield. At high laser intensity, electrons are directly accelerated by the laser and enter a highly radiative regime with up to 5% of their energy converted into x rays.     

A practical multi-step synthesis of ethyl N-functionalized $$\varvec{\upbeta }$$-amino benzimidazole acrylate derivatives as promising cytotoxic agents

A series of 16 new ethyl \(\upbeta \)-amino benzimidazole acrylate derivatives 12(a–p) with a (2E)-s-cis/trans conformation and bearing two points of diversity was designed and synthesized by using a multi-step strategy (reductive amination, deprotection in acidic media and transamination) in moderate to good yields from ethyl 3-dimethylamino-2-(1H-benzimidazol-2-yl)acrylate (5) and monosubstituted N-Boc diamines (7a,7b) as starting building blocks. Products 12 were evaluated for their in vitro cytotoxic potential against six selected human cell lines (Huh7-D12, Caco2, MDA-MB231, HCT116, PC3 and NCI-H727). Compounds 12a, 12e and 12l exhibited selective and micromolar antitumor activities against Huh7-D12 and Caco2 cell lines.     

A dielectrophoresis-based platform of cancerous cell capture using aptamer-functionalized gold nanoparticles in a microfluidic channel

In this paper, a microfluidic chip for the manipulation and capture of cancer cells was introduced, in which the combination of dielectrophoresis (DEP) and a binding method based on chemical interactions by using cell-specific aptamers was performed to enhance the capture strength and specificity. The device has been simply constructed from a straight-channel PDMS placed on a glass substrate that has patterned electrode structures and a self-assembled monolayer of gold nanoparticles (AuNPs). The target cells were transported to the manipulation area by flow and attracted down to the region between the electrodes under the influence of positive DEP force. This approach facilitated subsequent selective capture by the modified aptamers on the AuNPs. The distribution of the electric field in the channel has also been simulated to clarify the DEP operation. As a result, the device has been shown to effectively capture target lung cancer cells with a concentration as low as $2\times {10}^4$cells/mL. The capture specificity in a sample of mixed cells is up to 80.4%. This technique has the potential to be applied to detection methods for many types of cancer.     

f-block MOFs: A Pathway to Heterometallic Transuranics

A novel series of heterometallic f-block-frameworks including the first examples of transuranic heterometallic ²³⁸U/²³⁹Pu-metal–organic frameworks (MOFs) and a novel monometallic ²³⁹Pu-analog are reported. In combination with theoretical calculations, we probed the kinetics and thermodynamics of heterometallic actinide(An)-MOF formation and reported the first value of a U-to-Th transmetallation rate. We concluded that formation of uranyl species could be a driving force for solid-state metathesis. Density of states near the Fermi edge, enthalpy of formation, band gap, proton affinity, and thermal/chemical stability were probed as a function of metal ratios. Furthermore, we achieved 97 % of the theoretical maximum capacity for An-integration. These studies shed light on fundamental aspects of actinide chemistry and also foreshadow avenues for the development of emerging classes of An-containing materials, including radioisotope thermoelectric generators or metalloradiopharmaceuticals.     

Semi-discrete optimal transport: hardness,regularization and numerical solution

Mathematical Programming - Semi-discrete optimal transport problems, which evaluate the Wasserstein distance between a discrete and a generic (possibly non-discrete) probability measure, are...     

Raman characterization before and after rapid thermal annealing of CeO2 thin films grown by rf sputtering on (111) Si

We investigated by Raman spectroscopy (RS) the crystalline quality of CeO₂ thin films radio frequency magnetron sputtered on n‐type (111) Si substrates from CeO₂ target. The deposition temperature was in the range of 200–800 °C. We also realized structural investigations on CeO₂ layers after Rapid Thermal Annealing (RTA) performed in the range of 750–1000 °C for 30 s under nitrogen atmosphere. So this study displays that a high‐growth temperature and a high post‐growth‐RTA temperature improves the crystalline structure of the film. In fact, the best crystalline quality, which is close to the CeO₂ target taken as a reference, is obtained for a CeO₂ layer deposited at 800 °C and post‐annealed at 1000 °C for 30 s. Copyright © 2008 John Wiley & Sons, Ltd.