Uncooled 25 Gbit/s direct modulation of semi-insulating buried-heterostructure 1.3 μm AlGaInAs quantum-well DFB lasers

Uncooled 25 Gbit/s direct modulation of 1.3 mum DFB lasers is demonstrated. The 150 mum-long semi-insulating buried-heterostructure AIGalnAs quantum-well DFB lasers show clear eye-openings with dynamic extinction ratio of 5 dB up to 70degC. 13 km singlemode-fibre transmission experiments using the devices show low power penalty within 1.3 dB between 25 and 70degC. These characteristics are the first achievement by 1.3 mum directly modulated lasers.     

Engineering of Lipid Nanoparticles by the Multifunctionalization of the Surface with Amino Acid Derivatives for the Neutralization of a Target Toxic Peptide

Protein affinity reagents (e.g., antibodies) are often used for basic research, diagnostics, separations, and disease therapy. Although a lot of “synthetic” protein affinity reagents have been developed as a cost-effective alternative to antibodies, their low biocompatibility is a considerable problem for clinical application. Lipid nanoparticles (LNP) represent a highly biocompatible drug delivery agent. However, little has been reported that LNP itself works as a protein affinity reagent in living animals. Here, LNP is engineered for binding to and neutralizing a target toxic peptide in living animals by multifunctionalization with amino acid derivatives. Multifunctionalized LNP (MF-LNP) is prepared using amino acid derivative-conjugated lipids. Optimized MF-LNP exhibits nanomolar affinity to the target toxic peptide and inhibits toxic peptide-dependent hemolysis and cytotoxicity. In addition, MF-LNP captures and neutralizes the toxic peptide after intravenous injection in the bloodstream; in addition, MF-LNP does not release the toxic peptide in the accumulated organ. These results reveal the potential of using LNP as a highly biocompatible protein affinity reagent such as an antidote.     

Electrochemical and theoretical assessment of the effect of two biocides on the corrosion of petroleum steel in sulfur‐polluted Black Sea water

Although the inhibitory effects of different biocides continue to gain ever‐increasing importance, the corrosion inhibition of petroleum steel in the Black Sea water by such compounds remains largely uncharacterized. Thus, to study the effect of sulfate‐reducing bacteria, corrosion parameters in oxygen‐free medium contaminated with sulfur have been determined. The variation of corrosion rates with the addition of two biocides, glutaraldehyde (GA) and ammonium chloride (AC), has been determined by using Tafel extrapolation and linear polarization methods in sulfur‐polluted seawater, both with and without biocides. Overall, this experimental work, also corroborated by theoretical data, reveals that some concentrations of GA and AC act as effective biocides in sulfur‐polluted medium.     

Effect of Bismuth on hydrogen storage properties of melt-spun LaNi4.7-x Al0.3Bix (x = 0.0, 0.1, 0.2, 0.3) ribbons

The LaNi₅ intermetallic compound is an AB5 type hydrogen storage alloy which exhibits low operating temperature, easy activation, low pressure and tolerance to impurities. In this study, LaNi_4.7-x Al_0.3Bi_x (x = 0.0, 0.1, 0.2, 0.3) alloys were produced by melt-spinning technique and the effects of Al and Bi additions on the microstructure, thermal and hydrogen storage properties of LaNi₅ were investigated. The results showed that substitution of Ni with Al led to a desired decrease in absorption/desorption plateau pressure and hysteresis without a decrease in hydrogen storage capacity. In contrast, Bi substitution with Ni increased the absorption/desorption plateau pressure, reduced the hydrogen capacity and increased pulverization resistance of the alloy due to the formation of BiLa and AlNi₃ intermetallic phases at the grain boundaries.     

Ionization efficiency of evolved gas molecules from aerosol particles in a thermal desorption aerosol mass spectrometer: Laboratory experiments

Thermal desorption aerosol mass spectrometers (TDAMSs) with electron ionization are widely used for quantitative analysis of aerosol chemical composition, and the ionization efficiency of evolved gas molecules from aerosol particles is an important parameter for such analysis. We performed laboratory experiments using a custom-made TDAMS to investigate the key factors affecting ionization efficiency. Ammonium chloride (NH₄Cl) and ammonium iodide (NH₄I) were used as test compounds because their thermal decomposition products are expected to be simple (dominated by ammonia (NH₃) and hydrogen halide (HX)). The ion signals originating from NH₃ and HX were measured by altering the position of the ionizer relative to the vaporization point. The ratio of ion signal from NH₃ to that from HX increased with increasing divergence angle of evolved gas plumes, which suggests that the angular distribution of gas molecules could be an important factor affecting the ionization efficiency.

Copyright © 2018 American Association for Aerosol Research     

Estimating the imageability of words by mining visual characteristics from crawled image data

Multimedia Tools and Applications - Natural Language Processing and multi-modal analyses are key elements in many applications. However, the semantic gap is an everlasting problem, leading to...     

Orientation development in thermotropic liquid crystal polymers

Thermotropic liquid crystal polymers are a new class of polymeric materials that consist of rigid backbone molecules and thus, even in the quiescent condition, take extended chain conformation to form optically anisotropic melts. A systematic investigation was carried out on how this type of material responds to two basic flow fields: shear and elongation. Rheological properties of the polymer in these flow fields have also been measured. It was found that a high level of molecular orientation was readily obtained by elongational flow but not with shear flow. Specifically, extraordinarily high orientation was obtained when the melt was subjected to small elongational strains, whiel shear strain or shear rate had little effect. A possible mechanism to explain these behaviors is illustrated based on the existing observations or theories of rodlike molecules. This finding was used to interpret the orientation distribution in the extruded and injection-molded articles.     

Does Globalization Reduce or Enhance Democracy? A Micro Analysis Based on an 18 Country Cross-National Asia-Europe Survey

Does globalization have a positive or negative impact on democracy? One reason this problem has gone unsolved is found in the fact that most studies to date have not made systematic use of empirical data to test propositions concerning the relationship between globalization and democracy. While there have been studies that have made a pioneering systematic contribution through the use of macroeconomic and other aggregate statistics, this article empirically examines whether globalization enhances or constrains democracy by using cross-national survey data collected in 17 countries (the Asia-Europe Survey). Our empirical testing has shown that globalization tends to be positively correlated to democratic activism at the individual level, suggesting the possibility that experiences of globalization strengthen democracy.

     

Syntheses and characterizations of a new calixarene-porphyrin conjugate as electron transfer system

A new calixarene-based donor-acceptor system, cone conformer 1, was prepared for the first time. In this compound, the calix[4]arene serves to juxtapose a tri-chloroquinone acceptor near the porphyrin photo-donor plane. As to the conformational control, the cone conformer 1 gave two peaks of phenolic OH groups at 8.40 and 8.43 ppm. This shows that cone conformer 1 is stabilized by intramolecular hydrogen bonds. The fluorescence intensity of 1 was 35% of that for the control compound 2. This means the tri-chloroquinone group in 1 efficiently quenched the fluorescence of ZnP*. The shortest edge-to-edge separation of the chromophores of 1 is ca. 8 A (as judged by CPK models). This provides a new calixarene-based supramolecular system in which through-space donor-to-acceptor electron transfer is observed upon photoexcitation.