4,4′-(Propane-1,3-di­yl)dipyridinium tetra­chloridonickelate(II)

The title compound, (C13H16N2)[NiCl4] or (H2bpp)·NiCl4 [bpp is 1,3-bis­(4-pyrid­yl)propane], is isostructural with its already reported Cu, Zn and Hg analogues. The structure consists of a doubly charged (H2bpp)2+ cation and a tetra­hedral [NiCl4]2− dianion. Both pyridyl N atoms are protonated and form a (H2bpp)2+ cation which adopts an anti–anti conformation with a dihedral angle of 6.287 (7)° between the pyridyl rings. The two pyridyl N atoms are both involved in strong N—H⋯Cl hydrogen bonds, which link both units into a dimer

A Non-Collinear Mixing Technique to Measure the Acoustic Nonlinearity Parameter of Adhesive Bond from Only One Side of the Sample

The acoustic nonlinearity parameter (ANLP) of a material is often positively correlated with the damage in the material. Therefore, the ability to nondestructively measure the ANLP may enable the nondestructive characterization of the material’s remaining strength. In this work, we developed a non-collinear mixing technique to measure the ANLP of adhesive bonds. One of the most significant features of the new method is that it requires only one-side access to the adhesive bond being measured, which significantly increases it utility in field measurements. Specifically, the test sample considered in this study consists of two aluminum plates adhesively joined together through a commercial adhesive tape. The non-collinear wave mixing technique consists of generating a longitudinal wave and a shear wave by piezoelectric transmitters attached to the same surface of the sample under test. These waves are introduced into the sample in such an angle that they will mix at the adhesive bond region. Mixing of these two waves generates a shear wave that propagates back towards the surface where the two waves were generated. This mixing wave is then recorded by a shear wave receiver placed on the same surface where the longitudinal and shear wave transmitters are located. It was shown that amplitude of this mixing wave is proportional to the ANLP of the adhesive bond. To demonstrate the effectiveness of the newly developed technique, a freshly made adhesive sample was first measured using the non-collinear mixing technique to obtain the ANLP of the adhesive bond. This sample is then placed inside a thermal chamber for aging to change its ANLP. The sample was taken out the thermal chamber periodically to measure its ANLP. The measured results clearly show that the ANLP varies with aging time. Initially, the ANLP decreases with aging time, possibly due to further curing. Afterward, the ANLP begins to increase with aging time, likely due to aging induced damage in the polymer adhesive. To verify that the signals received from the shear wave receiver are indeed the mixing wave, the finite element method was used to simulate the wave motion in the test sample. The simulation results clearly show that the signals recorded by the shear wave receiver are indeed the desired mixing wave, whose amplitude is proportional to the ANLP of the adhesive bond

Preparation of SnS2 colloidal quantum dots and their application in organic/inorganic hybrid solar cells

Dispersive SnS2 colloidal quantum dots have been synthesized via hot-injection method. Hybrid photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3",7"dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline SnS2 quantum dots as electron acceptor have been studied. Photoluminescence measurement has been performed to study the surfactant effect on the excitons splitting process. The photocurrent of solar cells with the hybrid depends greatly on the ligands exchange as well as the device heat treatment. AFM characterization has demonstrated morphology changes happening upon surfactant replacement and annealing, which can explain the performance variation of hybrid solar cells

Distribution specificities of long-period comets' perihelia. Hypothesis of the large planetary body on the periphery of the Solar System

The present paper reviews selected aspects of the Guliyev's hypothesis about the massive celestial body at a distance of 250-400 AU from the Sun as well as the factor of comets transfer. It is shown, that the conjecture of the point around which cometary perihelia might be concentrated, is not consistent. On the issue of perihelia distribution, priority should be given to the assumption that there is a plane or planes around which the concentration takes place. A total of 24 comet groups were investigated. In almost all cases there are detected two types of planes or zones: the first one is very close to the ecliptic, another one is about perpendicular to it and has the parameters: ip = 86{\deg}, {\Omega}p = 271.7{\deg}. The existence of the first area appears to be related to the influence of giant planets. The Guliyev's hypothesis says that there is a massive perturber in the second zone, at a distance of 250-400 AU. It shows that number of aphelia and distant nodes of cometary orbits in this interval significantly exceeds the expected background. Analysis of the angular parameters of the comets, calculated relative to the second plane (reference point is the ascending node of a large circle) displays clear patterns: shortage of comets near i' = 180{\deg}, excess of them near B'= 0{\deg} (ecliptic latitude of perihelion) and shortage near B'=-90{\deg}. The analysis also shows irregularity of distant nodes, overpopulation of perihelion longitudes in the range 350{\deg}-20{\deg}. Plotted distributions of aphelia N(Q) and distant cometary nodes clearly indicate a perturbation of the natural course near 300 AU. On the basis of collected cometary data, we have estimated orbital elements of the hypothetical planetary body: a = 337 AU; e = 0.14; {\omega} = 57{\deg}; {\Omega} = 272.7{\deg}; i = 86{\deg}

DyRRen: A Dynamic Retriever-Reranker-Generator Model for Numerical Reasoning over Tabular and Textual Data

Numerical reasoning over hybrid data containing tables and long texts has recently received research attention from the AI community. To generate an executable reasoning program consisting of math and table operations to answer a question, state-of-the-art methods use a retriever-generator pipeline. However, their retrieval results are static, while different generation steps may rely on different sentences. To attend to the retrieved information that is relevant to each generation step, in this paper, we propose DyRRen, an extended retriever-reranker-generator framework where each generation step is enhanced by a dynamic reranking of retrieved sentences. It outperforms existing baselines on the FinQA dataset.Comment: 9 pages, accepted by AAAI 202

Ethyl 1-(6-chloro-3-pyridylmeth­yl)-5-methyl-1H-1,2,3-triazole-4-carboxyl­ate

In the title compound, C12H13ClN4O2, the triazole ring carries methyl and ethoxy­carbonyl groups, and is bound via a methyl­ene bridge to a chloro­pyridine unit. There is evidence for significant electron delocalization in the triazolyl system. Intra­molecular C—H⋯O and inter­molecular C—H⋯N hydrogen bonds stabilize the structure