The Rearrangment of 3‐Aminobenzo‐[b]thiophenes to Tricyclic Benzoisothiazoles as Result of a Simple Azo‐coupling Procedure

As a result of the reaction of ethyl 3‐amino‐4‐dimethylamino‐benzothiophene‐2‐carboxylate ( 1 ) with 2‐thiazolediazonium salt 2 , tricyclic ethyl 5‐(thiazol‐2‐yl)‐8‐(thiazol‐2‐yldiazenyl)‐5H‐isothiazolo[3,4,5‐d,e]cinnoline‐3‐carboxylate 4 , instead of the expected 7‐thiazolylazo derivative 3 , is formed. A mechanism in which sulfanyl cations occur as intermediates is proposed.     

Train sound radiation

The problem of sound radiation from a train is considered. This object has been simulated as sets of point sources uniformly distributed in the domain of a moving lengthened rectangle. The solution of the problem is obtained using integral Fourier transforms over the space coordinates and time. The integrals are calculated by using the stationary phase method. Numerical analysis is carried out for acoustic pressure and sound intensity.     

New measure of the dissipation region in collisionless magnetic reconnection

A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron's rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.