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: Disclosed is an adjustable roller carrier, comprising a roller carrier base (1), rollers (2) and a motor speed reducing driver, wherein both ends of the roller carrier base are each articulated with a roller bearing (3) and a roller carrier hydraulic jack (5), with the roller carrier hydraulic jack (5) being articulated with the roller bearing (3) and the roller (2) being mounted on the roller bearing. The roller carrier hydraulic jack and a hydraulic pump station thereof, and an electromagnetic valve are all placed inside a hollow roller carrier support so that not only the height and the center-to-center distance of the rollers are adjustable, but also the adjustable roller carrier has the advantages of being integrally compact in structure, and small in terms of occupied space. The adjustable roller carrier enables the steel pipe to rotate in a narrow space, can be fast lifted, and transported by railway. The adjustable roller carrier is convenient to operate and has high safety.

Abstract: Disclosed is an adjustable roller carrier, comprising a roller carrier base (1), rollers (2) and a motor speed reducing driver, wherein both ends of the roller carrier base are each articulated with a roller bearing (3) and a roller carrier hydraulic jack (5), with the roller carrier hydraulic jack (5) being articulated with the roller bearing (3) and the roller (2) being mounted on the roller bearing. The roller carrier hydraulic jack and a hydraulic pump station thereof, and an electromagnetic valve are all placed inside a hollow roller carrier support so that not only the height and the centre-to-centre distance of the rollers are adjustable, but also the adjustable roller carrier has the advantages of being integrally compact in structure, and small in terms of occupied space. The adjustable roller carrier enables the steel pipe to rotate in a narrow space, can be fast lifted, and transported by railway. The adjustable roller carrier is convenient to operate and has high safety.

Abstract: A speedy construction method for the penstock of a large scale hydraulic turbine is provided. The construction sequence thereof is as follows: the spiral case of the hydraulic turbine is installed firstly, then, upwards along the water flow direction, the penstock is arranged in turn from the intake section of the spiral case. The penstock is assembled and welded on a roll welding rack or on a penstock pallet car by use of segments so as to be installed rapidly.

Abstract: A speedy construction method for the penstock of a large scale hydraulic turbine is provided. The construction sequence thereof is as follows: the spiral case of the hydraulic turbine is installed firstly, the upwards along the water flow direction, the penstock is arranged in turn from the intake section of the spiral case. The penstock is assembled and welded on a roll welding rack or on a penstock pallet car by use of segments so as to be installed rapidly.