Abstract: An ultra-wideband electromagnetic band gap (EBG) structure includes multiple EBG units in an array. Each EBG unit includes a power plane, a dielectric substrate and a ground plane from top to bottom. The power plane includes a patch, a coupled complementary split ring resonator (C-CSRR) and a plurality of semi-improved Z-bridge structures. Each edge of the patch is provided with a semi-improved Z-bridge structure. The C-CSRR is provided within a ring formed by the semi-improved Z-bridge structures. The Z-bridge structure includes a first horizontal branch, a first vertical branch, a second horizontal branch and a second vertical branch connected in sequence. The second vertical branch is connected to the patch. First horizontal branches of adjacent EBG units are connected to each other. A circuit board including the aforementioned EBG structure is also provided.

Abstract: A long-distance high-voltage cable fault degree detection method. A cable fault positioning curve is obtained by using a frequency-domain reflection method, and a cable fault positioning compensation curve is determined by means of theoretical calculation in combination with the parameters of a frequency-domain incident signal, cable structure parameters, and characteristic parameters of each layer of materials of the field test; furthermore, a cable fault diagnosis curve is determined on the basis of the cable fault positioning curve and the cable fault positioning compensation curve, the severity of the fault is determined by means of the amplitude of a peak point of the cable fault diagnosis curve, and the accuracy of long-distance high-voltage cable fault degree diagnosis is effectively improved.

Abstract: The present disclosure provides a use of a novel environment-friendly agricultural chemical, and belongs to the field of agricultural chemicals. It is found in the present disclosure that methyl 4-hydroxyphenylacetate may be used for controlling plants and preparing herbicides. The methyl 4-hydroxyphenylacetate in the present disclosure has a use concentration greater than 150 mmol/L. The herbicide is prepared by using the methyl 4-hydroxyphenylacetate as an active ingredient in the present disclosure has a good controlling and killing effect on perennial herbs or Half-shrubby plants, especially Eupatorium adenophorum, and has low toxicity, no harm, and no solvent residues after use.

Abstract: A method for detecting a storage life of a pre-crosslinked material is provided. Tableting is performed on an unaged pre-crosslinked material to obtain crosslinked polyethylene. A crosslinking degree and a mechanical property of the crosslinked polyethylene are measured to obtain reference data. The pre-crosslinked material is heated to obtain a fast-aged pre-crosslinked material. The crosslinking degree and mechanical property of crosslinked polyethylene obtained from the fast-aged pre-crosslinked material are measured to obtain measurement results, which are compared with the reference data. If comparison results all fall within corresponding ranges, the time period of heating is increased by a step to repeat the above steps until the comparison results do not all fall within the corresponding ranges. A result obtained by subtracting the step from the time period of heating is converted into a time period of storage at the room temperature.