Abstract: A reduction gearbox for solar photovoltaic tracking includes a housing, an end cover, a gear, and a worm. A first limiting stopper is disposed on the top of the housing. A first limiting protrusion and a second limiting protrusion are disposed on a side of a gear ring of the gear, and the first limiting stopper, the first limiting protrusion and the second limiting protrusion define a hard limiting structure. The sum of an included angle between outer end surfaces of the first and second limiting protrusions and a central angle of the first limiting stopper is less than or equal to 170°. The difference between a central angle of the gear ring of the gear and a central angle of the worm is greater than or equal to 180°.

Abstract: A reduction gearbox for solar photovoltaic tracking is provided. A sum of an included angle between an outer end surface of a first limiting protrusion and an outer end surface of a second limiting protrusion and a central angle of a limiting stopper is less than or equal to 170°, that is, an angle at which a gear rotates from a hard limiting position of the first limiting protrusion and the limiting stopper to a hard limiting position of the second limiting protrusion and the limiting stopper is greater than or equal to 190°. A difference between a central angle of a gear ring of the gear and a central angle of a worm is greater than or equal to 180°. A photovoltaic panel may be rotated to be perpendicular to the ground, so that snow accumulated on a photovoltaic panel surface can be cleared to the utmost extent.

Abstract: A gate structure of flow guiding sediment bypass tunnel with self-adaptive inlet adjustment the gate structure comprises a sediment bypass tunnel main body, wherein: the sediment bypass tunnel main body comprises a second revolution wheel, a second braking rim, a top water stopper plate and a weir, a second regulator is provided at a front side of the sediment discharge tunnel, the second revolution wheel is provided at a top portion of the second regulator, a top portion of the second revolution wheel is welded with the second valve lever, the second valve lever is connected with the top portion of the second regulator, and by providing the flow guiding structure at the bottom portion bottom water flows with higher sediment concentrations can be guided into the tunnel; and the altitude of the flow guiding inlet at the bottom portion can be automatically controlled with the gate structure.

Abstract: A high-magnesium glass fiber composition with high specific modulus and a glass fiber is provided. The glass fiber composition includes the following contents of components in percentage by mass: 58.5-63.0% of SiO2, 15.0-20.0% of Al2O3, 0.3-2.5% of CaO, 16.0-19.5% of MgO, 0.2-0.6% of Fe2O3, 1.0-3.5% of Y2O3 and B2O3, 0.1-1.0% of B2O3, and 0.3-0.8% of K2O and Na2O. The glass fiber composition has a density of less than 2.610 g/cm3, and the glass fiber has an elasticity modulus of equal to or greater than 94.0 GPa and a specific modulus of equal to or greater than 3.67*106 m.

Abstract: A display apparatus (HMD) is used by being worn by a user and includes: two lens barrels each including a closed bottom; eye cups in a barrel shape and disposed along open ends of the lens barrels; bendable temple parts that support the lens barrels by being worn by the user in an extended state; a detector that detects whether the display apparatus is worn by the user; and a drive mechanism that changes an orientation of the eye cups from a first orientation to a second orientation when the detector detects removal of the display apparatus from the user. The first orientation is an orientation which allows the user to wear the display apparatus and in which the eye cups interfere with the temple parts when bent. In the second orientation, the eye cups do not interfere with the temple parts when bent.

Abstract: The invention discloses an integrated digital PCR instrument and a control method therefor.

Abstract: A gate structure of flow guiding sediment bypass tunnel with self-adaptive inlet adjustment the gate structure comprises a sediment bypass tunnel main body, wherein: the sediment bypass tunnel main body comprises a second revolution wheel, a second braking rim, a top water stopper plate and a weir, a second regulator is provided at a front side of the sediment discharge tunnel, the second revolution wheel is provided at a top portion of the second regulator, a top portion of the second revolution wheel is welded with the second valve lever, the second valve lever is connected with the top portion of the second regulator, and by providing the flow guiding structure at the bottom portion bottom water flows with higher sediment concentrations can be guided into the tunnel; and the altitude of the flow guiding inlet at the bottom portion can be automatically controlled with the gate structure.

Abstract: A compound represented by formula (I) and a pharmaceutically acceptable salt thereof, as well as an antifungal application of the compound.

Abstract: A pyram-shaped deep-sea pressure-resistance shell and a design method therefor. The shell comprises a conical shell, an annular combined shell, a cylindrical shell, a flange bolt, and a perforated thick plate; a bottom end of the conical shell is connected with a top end of the annular combined shell, the conical shell being in communication with an interior part of the annular combined shell; the perforated thick plate blocks the bottom end of the annular combined shell, the perforated thick plate and the annular combined shell being connected by means of multiple flange bolts; the cylindrical shell is disposed inside the annular combined shell, a lower end of the cylindrical shell being inserted in a gap between the annular combined shell and the perforated thick plate.

Abstract: A pyram-shaped deep-sea pressure-resistance shell and a design method therefor. The shell comprises a conical shell, an annular combined shell, a cylindrical shell, a flange bolt, and a perforated thick plate; a bottom end of the conical shell is connected with a top end of the annular combined shell, the conical shell being in communication with an interior part of the annular combined shell; the perforated thick plate blocks the bottom end of the annular combined shell, the perforated thick plate and the annular combined shell being connected by means of multiple flange bolts; the cylindrical shell is disposed inside the annular combined shell, a lower end of the cylindrical shell being inserted in a gap between the annular combined shell and the perforated thick plate.

Abstract: Provided are highly water-resistant, flexible cementitious coating compositions comprising: an aqueous styrene-butadiene latex, one or more epoxy silane, cement, and one or more solid filler. The epoxy silane may comprise one or more epoxy functional groups and one or more hydrolysable functional groups selected from siloxy, silane, and, silanol or combinations thereof. Also provided are kits comprising the components of the cementitious coating compositions, methods for providing coatings, layers or membranes derived from such wet compositions, as well as the coatings, layers or membranes derived therefrom.

Abstract: Provided are highly water-resistant, flexible cementitious coating compositions comprising: an aqueous styrene-butadiene latex, one or more epoxy silane, cement, and one or more solid filler. The epoxy silane may comprise one or more epoxy functional groups and one or more hydrolysable functional groups selected from siloxy, silane, and, silanol or combinations thereof. Also provided are kits comprising the components of the cementitious coating compositions, methods for providing coatings, layers or membranes derived from such wet compositions, as well as the coatings, layers or membranes derived therefrom.

Abstract: A method for controlling an antenna of a mobile communication application system based on double quaternions in MEMS inertial navigation. The method comprises: introducing an antenna control quaternion based on a navigation attitude quaternion; in each interrupt cycle of a navigation computer, updating the two quaternions respectively using a carrier system measured by a gyroscope relative to a rotation vector of an ideal platform coordinate system; in each filter cycle, correcting the error of the navigation attitude quaternion respectively using a Kalman filter; according to the relationship between the attitudes determined by the two attitude quaternions, determining the angular speed in an antenna control instruction; and finally, driving a servo system to rotate at an antenna servo control angle converted by an antenna control quaternion attitude.

Abstract: A method for controlling an antenna of a mobile communication application system based on double quaternions in MEMS inertial navigation. The method comprises: introducing an antenna control quaternion based on a navigation attitude quaternion; in each interrupt cycle of a navigation computer, updating the two quaternions respectively using a carrier system measured by a gyroscope relative to a rotation vector of an ideal platform coordinate system; in each filter cycle, correcting the error of the navigation attitude quaternion respectively using a Kalman filter; according to the relationship between the attitudes determined by the two attitude quaternions, determining the angular speed in an antenna control instruction; and finally, driving a servo system to rotate at an antenna servo control angle converted by an antenna control quaternion attitude.