Abstract: An equatorial mount for providing a telescope with a balanced weight distribution is described. The equatorial mount includes a base, a declination base, and a device support. The declination base is rotatable about a right ascension axis relative to the base. The device support is rotatable about a declination axis relative to the declination base. The declination axis intersects orthogonally with the right ascension axis and the declination axis intersects a midsection of the declination base. The declination base includes a counterweight assembly extending along a counterweight axis, the counterweight axis being spaced away from the declination axis along the right ascension axis.

Abstract: An equatorial mount having a base, a right ascension base, a right ascension shaft, a declination base, a declination shaft, and a mount-rotation mechanism, the declination base rotatable about a right ascension axis relative to the right ascension base, and the declination shaft rotatable about a declination axis relative to the declination axis, wherein the mount-rotation mechanism is engageable and disenagageable from one or the other of the right ascension shaft and the declination shaft, to apply torque between the declination base and that shaft when engaged and to permit relative rotation of the shaft and the declination base when disengaged.

Abstract: An equatorial mount having a base, a right ascension base, a right ascension shaft, a declination base, a declination shaft, and a mount-rotation mechanism, the declination base rotatable about a right ascension axis relative to the right ascension base, and the declination shaft rotatable about a declination axis relative to the declination axis, wherein the mount-rotation mechanism is engageable and disenagageable from one or the other of the right ascension shaft and the declination shaft, to apply torque between the declination base and that shaft when engaged and to permit relative rotation of the shaft and the declination base when disengaged.

Abstract: An equatorial mount for providing a telescope with a balanced weight distribution is described. The equatorial mount comprises a base, a declination base, and a device support. The declination base is rotatable about a right ascension axis relative to the base. The device support is rotatable about a declination axis relative to the declination base. The declination axis intersects orthogonally with the right ascension axis and the declination axis intersects a midsection of the declination base. The declination base comprises a counterweight assembly extending along a counterweight axis, the counterweight axis being spaced away from the declination axis along the right ascension axis.

Abstract: A preparation method of a nanosheet nitrogen-containing porous carbon material includes steps of: dissolving alkali and water-soluble amine-containing compound in water, forming an aqueous solution; adding cellulose or a derivative thereof into the aqueous solution; after mixing and drying, obtaining a crystal composite of the alkali and the water-soluble amine-containing compound, wrapped by the cellulose or the derivative thereof; carbonizing the crystal composite under nitrogen gas flow; washing a crabonized product; and obtaining the nanosheet nitrogen-containing porous carbon material. Through changing a proportion among the alkali, the water-soluble amine-containing compound and the cellulose or the derivative thereof, a specific surface area, pore structure, nitrogen content and thickness of the nanosheet nitrogen-containing porous carbon material are adjusted.