Abstract: A method for quickly optimizing key mining parameters of an outburst coal seam as provided includes steps of constructing a graphic basic information model of the coal mine, giving coal mine characteristic information, performing mining simulation, constructing a CNN-LSTM predicating model, obtaining changes under different mining conditions, constructing a Lorenz chaotic primer, and the like. The model can be improved with continuous breakthroughs in theory, so that the model has a strong learning ability and can adapt to the constantly changing complex geological environment. The method has very good predictability for the determination of coal seam group parameters, and can efficiently select and output a set of candidate parameters.

Abstract: A first aspect of the present invention provides a method for the preparation of 2-chloro-5-chloromethylpyridine, comprising: performing a cyclization reaction on 4,5-dichloro-4-methoxypentanenitrile in presence of a silicon compound and an acylamide compound to obtain 2-chloro-5-chloromethylpyridine. Another aspect of the present invention provides a method for preparation of 2-(chloromethyl)-5-(trifluoromethyl)-1,3,4-oxadiazole, comprising: performing a cyclization reaction on 1-(chloroacetyl)-2-(trifluoroacetyl)hydrazine in a presence of a silicon compound and an acylamide compound to obtain 2-(chloromethyl)-5-(trifluoromethyl)-1,3,4-oxadiazole. The silicon compound or/and acylamide compound provided by the present invention serve as cyclization reagents and have high efficiency.

Abstract: A self-adaptive constant-current driving circuit for a three-channel multi-color LED, including a decoder, a two-phase non-overlapping circuit, and a LED constant-current driving circuit, where the decoder determines the number of lighted channels according to a first input signal, and generates a first switch control signal and a second switch control signal; the two-phase non-overlapping circuit modulates the first switch control signal into a first two-phase non-overlapping signal and a second two-phase non-overlapping signal, and modulates the second switch control signal into a third two-phase non-overlapping signal and a fourth two-phase non-overlapping signal; the LED constant-current driving circuit controls an on/off state of the respective channel of LED according to a second input signal, and outputs a current for controlling a brightness of the respective channel of LED according to the first two-phase non-overlapping signal, the second two-phase non-overlapping signal, the third two-phase non-ove

Abstract: An information handling system includes a printed circuit board. The printed circuit board includes first and second pads of a first differential pair, a hatched ground, and first and second traces of a second differential pair. The first and second pads of the first differential pair are routed a surface of the printed circuit board. The hatched ground routed within a first layer of the printed circuit board. The first and second traces of the second differential pair are routed below the first and second pads and the hatched ground within a second layer of the printed circuit board. The hatched ground dampens crosstalk between signals on the traces and signals on the differential pair pads.