Molecular dynamics of laser-assisted decomposition of unstable molecules at the surface of carbon nanotubes: case study of CH2(NO2)2 on CNT(4,0)

ABSTRACT

In this study, photoreactions of the dinitromethane molecule noncovalently adsorbed on the (4, 0) carbon nanotube (CNT) have been investigated by time-dependent, excited-state molecular dynamics, which takes into account simultaneous evolution of electronic excitation and nuclear positions under periodic optical excitations. It is found that desorption of molecular adsorbate from CNT surface can be controlled by UV?vis photoexcitations. In addition, it is shown that the presence of CNT substrate facilitates photodecomposition of the adsorbate molecule, related to optically controlled explosion. This model demonstrates potential of photoinduced charge transfer between the adsorbate and substrate, which can affect efficiency of desorption and decomposition reactions. This process has a potential use as a remote trigger for larger scale detonations, or as a mechanism for ‘cleaning’ CNTs of unwanted functionalisation.     

Approximation by Nörlund means of double Fourier series for Lipschitz functions

We study the rate of uniform approximation by Nörlund means of the rectangular partial sums of the double Fourier series of a function |(x, y) belonging to the class Lip α, 0 < α 1, on the two-dimensional torus −π < x, y π. As a special case we obtain the rate of uniform approximation by double Cesàro means.     

A new and high yielding synthesis of unstable pyrroles via a modified Clauson-Kaas reaction

An investigation of the reaction requirements to effect the Clauson-Kaas pyrrole synthesis led to the formulation of a new procedure that avoids the contact of pyrroles to heat or strongly acidic conditions that cause decomposition of the desired products. The procedure involves mild hydrolysis of 2,5-dimethoxytetrahydrofuran in water to the activated species 2,5-dihydroxytetrahydrofuran that reacts with primary amines in an acetate buffer at room temperature to give N-substituted pyrroles in high yield. In the case of chiral amines, pyrrole formation proceeds with no detectable epimerisation. Acid- or heat-sensitive pyrroles are also obtained in high yield and purity.     

The point spectra for certain classes of operators in B(ℓ p )

In a recent paper [5] Maddox determined the point spectrum of the Cesaro matrices of order >0, considered as series-to-series operators. In this paper we obtain the point spectrum for the Endl generalized Hausdorff matrices, the Hausdorff matrices, and for a wide class of generalized Hausdorff matrices, which include the Endl and ordinary Hausdorff matrices as special cases. We also obtain point spectrum results for a wide class of weighted mean matrices. Since the Cesaro matrices are examples of Hausdorff matrices, our results contain the corresponding theorems of Maddox as special cases.     

Polyharmonic Maass forms for $$\text {PSL}(2,{\mathbb Z})$$

We discuss the space of polyharmonic Maass forms of even integer weight on \(\text {PSL}(2,\mathbb Z)\backslash \mathbb H\). We explain the role of the real-analytic Eisenstein series \(E_k(z,s)\) and the differential operator \(\frac{\partial }{\partial s}\) in this theory.     

A mechanistic study on the oxidation of hydrazides: application to the tuberculosis drug isoniazid

Herein we report radical trapping experiments that support the formation of an acyl radical as the active species from the oxidation of isoniazid; these data provide insight into the mechanism of hydrazide oxidation.     

Projectile detection using quasi-electrostatic field sensor array

Detection, localization, and ranging of the hostile fire source are very important for military and law enforcement operations. In this work authors explore use of quasi-electrostatic field created by a moving, charged projectile for the projectile detection. This paper describes development of a novel and inexpensive sensor network for detecting the quasi-electrostatic field of a charged bullet. The principle method used to sense the quasi-electrostatic field was based on a novel sensor utilizing voltage-controlled variable capacitance. A wired network was used to propagate the measurements to a central data acquisition unit. Several missile localization algorithms were explored to process the data from the sensor array making sure that all variables, including signal latency, would not affect the accuracy of the results. The results received and processed by the system report the passing objects coordinated in relation to the designated central location.