Abstract: A power control method and a device are provided. A network device generates, according to a coverage ratio of actual coverage performance between a second user direct connection communication device and a first user direct connection communication device to expected coverage performance of the first user direct connection communication device, a power adjustment indication message, and sends the power adjustment indication message to the first user direct connection communication device; and the first user direct connection communication device controls transmit power according to the power adjustment indication message.

Abstract: The present invention relates to a Photoelastic Modulator (PEM), particularly to a novel polarized light modulator structure based on a photoelastic effect. The PEM, which controls driving voltages of two groups of piezoelectric actuators, is able to implement polarized light modulation having a relatively large optical path difference, and polarized light modulator having a fast modulation shaft moving circumferentially, and the PEM operates stably without a moving component. The present invention includes the piezoelectric actuators, a light pass crystal and a driver controller. Two light pass faces of the light pass crystal are parallel regular octagons directly facing each other, and identical rectangles are formed by side faces of the light pass crystal. The piezoelectric actuators are in soft connection with middle positions of the rectangles by connection rubber layers.

Abstract: A method for improving plant insect resistance includes providing target genes derived from insects. Constructs based on the nucleotide sequences of these target genes are designed to form interfering molecules. After being eating by insects, the plant can significantly inhibit expression of corresponding genes in insects. This inhibition is not affected by barrier of the insect digestive systems. The method can improve the insect resistance of plants, reduce pesticide applications, lower the costs of agricultural production, and protect the environment.