Abstract: A laser marking method for an electronic device with a projector and a projection screen includes first and second microwaves being received by microwave receivers on corners or elsewhere of the projection screen. First and second microwave transmitters in a laser pen transmit the microwaves. Time intervals between transmissions and receptions of the microwaves are acquired. Distances between each of the microwave receivers and each of first and second microwave transmitters are calculated, to establish a three-dimensional rectangular coordinate system. Coordinate value of a point on the screen struck by laser beam (drop point) from the pen is calculated. The method allows for marking the drop point on the screen and also for marking a series of drop points with a line when the laser beam moves across the screen.

Abstract: A laser marking method for an electronic device with a projector and a projection screen includes first and second microwaves being received by microwave receivers on corners or elsewhere of the projection screen. First and second microwave transmitters in a laser pen transmit the microwaves. Time intervals between transmissions and receptions of the microwaves are acquired. Distances between each of the microwave receivers and each of first and second microwave transmitters are calculated, to establish a three-dimensional rectangular coordinate system. Coordinate value of a point on the screen struck by laser beam (drop point) from the pen is calculated. The method allows for marking the drop point on the screen and also for marking a series of drop points with a line when the laser beam moves across the screen.

Abstract: A cathode composite material includes a cathode active material and a coating layer coated on a surface of the cathode active material. A material of the coating layer is a lithium metal oxide having a crystal structure belonging to C2/c space group of the monoclinic crystal system. The present disclosure also relates to a lithium ion battery including the cathode composite material.

Abstract: A cathode composite material includes a cathode active material and a coating layer coated on a surface of the cathode active material. A material of the coating layer is a lithium metal oxide having a crystal structure belonging to C2/c space group of the monoclinic crystal system. The present disclosure also relates to a lithium ion battery including the cathode composite material.

Abstract: A modem user management system is configured for managing a plurality of user terminals with different Internet protocol (IP) addresses and users associated with different groups in a communication network. The system receives an IP address of one of the user terminals and a group type of the user of the user terminal and compares the IP addresses to determine whether the user terminal belongs to a local area network of the communication network. The system further determines whether the user is associated with an administrative group and activates an administrative interface of the modem user management system for a user upon receiving the proper login privileges.