Abstract: This application provides an omnidirectional dual-polarized antenna and a communications device. The omnidirectional dual-polarized antenna includes a first printed circuit board, a feeding structure, a feeding strip, and grounding strips. A metal ring structure and a metal disc structure are arranged on the first printed circuit board, and the metal ring structure surrounds the metal disc structure. The feeding structure is perpendicular to the first printed circuit board and connected to the metal ring structure. The feeding strip is perpendicular to the first printed circuit board and connected to a central point of the metal disc structure. The grounding strips are each perpendicular to the first printed circuit board and connected to the metal disc structure. The metal ring structure and the feeding structure form a horizontally polarized unit, and the metal disc structure, the feeding strip, and the grounding strips form a vertically polarized unit.

Abstract: A low-temperature device for separating and purifying gas based on a small-sized low-temperature refrigerating machine includes a primary, secondary and quaternary heat exchanger, at least one small-sized low-temperature refrigerating machine, and at least one liquid collecting tank. The small-sized low-temperature refrigerating machine includes a first cold head and a second cold head, the secondary heat exchanger is provided on the first cold head to form a primary cold head heat exchanger, the quaternary heat exchanger is provided on the second cold head to form a secondary cold head heat exchanger, a mixed gas outlet is connected to an inlet of the primary cold head heat exchanger. By using primary and secondary cold heads of the small-sized low-temperature refrigerating machine as cold sources, gases having different condensing temperature are liquefied and solidified separately, and two or more gases can be separated and purified at a lower cost.

Abstract: A pulse tube refrigerator with an automatic gas flow and phase regulating device is composed by a helium compressor, an air distribution valve, a drive controller, a drive lead, a temperature sensor, a temperature measuring lead, a heat regenerator, a first-stage pulse tube, a second-stage pulse tube, a first-stage air reservoir and a second-stage air reservoir, wherein the air distribution valve is consisted of eight independent valves. According to received temperature signals from the temperature sensors the drive controller transmits order signals to the eight independent valves so as to control the open/close degree, time and sequence of the eight valves of the air distribution valve.

Abstract: A low-temperature device for separating and purifying gas based on a small-sized low-temperature refrigerating machine includes a primary, secondary and quaternary heat exchanger, at least one small-sized low-temperature refrigerating machine, and at least one liquid collecting tank. The small-sized low-temperature refrigerating machine includes a first cold head and a second cold head, the secondary heat exchanger is provided on the first cold head to form a primary cold head heat exchanger, the quaternary heat exchanger is provided on the second cold head to form a secondary cold head heat exchanger, a mixed gas outlet is connected to an inlet of the primary cold head heat exchanger. By using primary and secondary cold heads of the small-sized low-temperature refrigerating machine as cold sources, gases having different condensing temperature are liquefied and solidified separately, and two or more gases can be separated and purified at a lower cost.

Abstract: The invention relates to a pulse tube refrigerator with an automatic gas flow and phase regulating device, comprising a helium compressor (1), an air distribution valve (11), a drive controller (9), a drive lead (10), a temperature sensor, a temperature measuring lead (8), a heat regenerator, a first-stage pulse tube (5), a second-stage pulse tube (6), a first-stage air reservoir (14) and a second-stage air reservoir (15), wherein said air distribution valve (11) comprises eight independent valves of a first valve (21), a second valve (22), a third valve (23), a fourth valve (24), a fifth valve (25), a sixth valve (26), a seventh valve (27) and an eighth valve (28).