Abstract: Systems, apparatus, and methods for detecting air breathed by a user and/or one or more gases are provided herein. In some embodiments, an apparatus may include a test material adapted to reduce in size when exposed to one or more stimuli. In some embodiments, one or more chemicals may be disposed on the test material and, when exposed to the air breathed by the user, the one or more chemicals are adapted to transform from a first color to a second color. In some embodiments, when the test material reduces in size an intensity of the second color increases. The apparatus may further include a face mask. In this regard, the test material may be removably attached to the face mask. The apparatus may further include a spectrophotometer configured to determine if the one or more chemicals have transformed from the first color to the second color.

Abstract: A multi-channel radio frequency transceiving device includes an optical module, a digital signal processing module, a radio frequency transceiving module, a downlink module, and a microprocessing module. The optical module receives an optical signal corresponding to baseband data, converts the optical signal into an electric signal, and outputs the electric signal to the digital signal processing module. The digital signal processing module obtains the baseband data and channel number information on the basis of the electric signal, and allocates and processes the baseband data. The microprocessing module determines the number of working channels of the radio frequency transceiving module, the corresponding number of working channels of the downlink module and a downlink output power on the basis of the channel number information and the baseband data, and closes the remaining channels in the downlink module.

Abstract: A high-pressure self-sealing butterfly valve, which comprises a valve body and a valve shaft, wherein a flow channel and a butterfly plate are arranged in the valve body, a pure metal sealing ring and a pure metal valve seat are sequentially arranged at a portion, on the outer side of the butterfly plate, of the flow channel, a piston cavity is further formed in a flow direction end face of the pure metal valve seat, and an upper valve shaft and a lower valve shaft are arranged at the upper end and the lower end of the valve shaft respectively; an upper end cover assembly and an upper self-sealing assembly are arranged between the end part of the upper valve shaft and the valve body, a lower sealing bottom cover and a lower self-sealing assembly are arranged between the end part of the lower valve shaft and the valve body.

Abstract: A high-pressure self-sealing butterfly valve, which comprises a valve body and a valve shaft, wherein a flow channel and a butterfly plate are arranged in the valve body, a pure metal sealing ring and a pure metal valve seat are sequentially arranged at a portion, on the outer side of the butterfly plate, of the flow channel, a piston cavity is further formed in a flow direction end face of the pure metal valve seat, and an upper valve shaft and a lower valve shaft are arranged at the upper end and the lower end of the valve shaft respectively; an upper end cover assembly and an upper self-sealing assembly are arranged between the end part of the upper valve shaft and the valve body, a lower sealing bottom cover and a lower self-sealing assembly are arranged between the end part of the lower valve shaft and the valve body.

Abstract: An auxiliary control circuit (100) for a power amplification module, a power amplification module, and a communication device. The auxiliary control circuit (100) for the power amplification module comprises a main control chip (201), a current detection chip (12), and a precision adjustment unit (14). The precision adjustment unit (14) is connected in parallel to a precision control resistor of the current detection chip (12), and a switch control terminal of the precision adjustment unit (14) is electrically connected to the main control chip (201) and is used for adjusting an output voltage amplification factor of the current detection chip (12) when a switch signal outputted by the main control chip (201) is received. A detection input terminal of the current detection chip (12) is used for accessing a voltage to be measured of a power amplifier transistor power supply circuit (102) of the power amplification module.

Abstract: a high-power uplink and downlink switching device and a communication apparatus are disclosed. A radio frequency switch and a synchronization control module of the device cooperate. A circulator has a first port connected to an output end of a power amplification module, a second port connected to a second radio frequency port, and a third port connected to a low-noise amplifier module via a first radio frequency switch. The third port is further connected to a high-power load resistor and a second radio frequency switch via a first microstrip line, so as to be separately grounded. A radio frequency impedance from a first end to a second end of the first microstrip line is in a high-impedance state.

Abstract: The present invention provides a terminal and an information interaction method. The terminal comprises an identification generation unit and a notification unit. The identification generation unit generates a request message identification when receiving a request sent out by any group member of a social networking service group, and controls a display unit of the terminal to display the request message identification at a preset position of a page of the social networking service group. The notification unit receives a response operation performed by another group member on the request message identification, and notifies the any group member of a response message.