The Uncertainty Principle for the Two-Sided Quaternion Fourier Transform

In this paper, we give an upper bound for the first eigenvalue of the p-Laplacian of Finsler submanifolds in Minkowski spaces. Our results extend those of Wu (Ann Glob Anal Geom 29:95–102, 2006), and Du and Mao (Front Math China 10:583–594, 2015).

     

Selective Separation of Uranium(VI), Thorium(IV), and Lanthanum(III) from Their Aqueous Solutions using a Chelating Resin Containing Amine Functionality

A glycidyl methacrylate/divinylbenzene resin containing triethylenetetramine functional group was synthesized. The adsorption behavior of the obtained resin toward U(VI), Th(IV), and La(III) in aqueous solutions was investigated by batch and column techniques at different experimental conditions. Kinetic and thermodynamic characteristics of the adsorption process have been investigated. The regeneration of the loaded resin was also studied.     

Molding versus dispersion: effect of the preparation procedure on the capacitive and cycle life of carbon nanotubes aerogel composites

Binderless carbon nanotubes aerogel (CNAG) composites represent a new class of high-performing electrodes for energy storage applications such as electrochemical double layer capacitors. The composites developed here differ significantly from these previously prepared with dispersion processes. The CNAG material was prepared by a molding procedure that is the synthesis by a chemical vapor deposition method to grow carbon nanotubes directly onto a microfibrous carbon paper substrate. Then the carbon aerogel is synthesized on the carbon nanotubes. The key feature of the method is eliminating the need of controlling the carbon nanotube concentration, which permits optimized dispersion processes to reinforce the aerogel's networks. The CNAG electrode delivered very high specific capacitances of 524 F g⁻¹ in KOH electrolyte and 280 F g⁻¹ in H₂SO₄ electrolyte. Furthermore, this better integration of carbon nanotubes in the matrix of carbon aerogel improved its resistance to the attack by the electrolyte and conferred an excellent cycle life over 5,000 cycles of charge–discharge in both electrolytes.     

Sub-Poissonian fluctuations in a 1D Bose gas: from the quantum quasicondensate to the strongly interacting regime

We report on local, in situ measurements of atom number fluctuations in slices of a one-dimensional Bose gas on an atom chip setup. By using current modulation techniques to prevent cloud fragmentation, we are able to probe the crossover from weak to strong interactions. For weak interactions, fluctuations go continuously from super- to sub-Poissonian as the density is increased, which is a signature of the transition between the subregimes where the two-body correlation function is dominated, respectively, by thermal and quantum contributions. At stronger interactions, the super-Poissonian region disappears, and the fluctuations go directly from Poissonian to sub-Poissonian, as expected for a "fermionized" gas.     

Improved Synthesis of 10-(2-Alkylamino-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic Acid Derivatives Bearing Acid-Sensitive Linkers

Alkylation of the hydrobromide salts of 1,4,7-tris(methoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane and 1,4,7-tris(ethoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane with appropriate α-bromoacetamides, followed by hydrolysis, provides convenient access to 10-(2-alkylamino-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derivatives that contain acid-sensitive functional groups. The utility of the method is demonstrated by improved syntheses of two known 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid monoamides bearing acid-sensitive ω-tritylthio alkyl chains in much greater yields based on cyclen as the starting material.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Comparative investigation of operational performance characteristics of axially grooved and arterial heat pipes

The thermal performance characteristics of an axially grooved heat pipe (AGHP) and an arterial heat pipe (ArHP) sharing a similar external configuration are investigated. A mathematical model is developed to predict the capillary heat transfer limit for both heat pipes. The meniscus attachment point, contact angle and liquid–vapor interfacial shear stress are taken into account in this model. In particular, for predicting the ArHP dry-out, a novel model is proposed by introducing two different failure mechanisms. The results of the mathematical model are experimentally verified.     

Energetics of phase transformations in polyethylene

The molecular mechanisms involved in the orthorhombic-to-monoclinic phase transformation in polyethylene were investigated by the computer simulation of a structure–energy map based on empirically justified intermolecular potential functions. Stable packing structures for the orthorhombic and monoclinic form were isolated as relative minima, cohesive energies were determined from the energy minima, specific chain motions involved in the transformation were identified by the minimum energy path connecting the packing minima, and the activation energy for the transformation was determined from the energy barrier along the minimum energy transformation path. The packing structure parameters predicted from the energy map were in excellent agreement with unit cell dimensions observed near 0°K. The activation energy predicted for the transformation is relatively low (～0.5 kcal/mole of ethylene at 0°K and 0.25 kcal/mole of ethylene near the melting point, 411°K). Monoclinic packing was predicted to be slightly more stable than orthorhombic. Since this result is inconsistent with a large body of observations, we propose that the intramolecular energy of chain folds plays a dominant role in establishing chain-packing geometry. The inclusion of fold-transition energetics could give rise to transformation mechanisms which differ in details from those proposed in this work.     

New generation of functionalized bipyrazolic tripods: synthesis and study of their coordination properties towards metal cations

A simple and easily synthesis of new generation of N-donor bipyrazolic tripods by coupling of functionalized pyrazole derivatives and an appropriate primary amine derivative via condensation or nucleophilic substitution reaction is presented. The complexation capacity of these compounds towards bivalent metal ions (Hg²⁺, Cu²⁺, Pb²⁺, Cd²⁺) and alkaline metal ions (Li⁺, Na⁺, K⁺) were investigated using the liquid–liquid extraction process. The percentage limits of extraction were determined by atomic absorption measurements.