Abstract: The present disclosure provides an underwater detection method for contact leakage of a tunnel joint of a dam culvert, including: obtaining an underwater image sequence of the culvert by an underwater robot; preprocessing and registering the underwater image sequence; extracting particle information appearing in the underwater image sequence based on the registered underwater image sequence; constructing a three-dimensional fluid velocity distribution map based on the particle information, and determining leakage situation according to the three-dimensional fluid velocity distribution map; and superimposing the three-dimensional fluid velocity distribution map on a preconfigured three-dimensional culvert model, and rendering and displaying it.

Abstract: The present disclosure provides a clock signal generation circuit and method, and a memory. The circuit includes: a command predecoding circuit, configured to decode partial command bits in a command, to obtain a predecoded command signal; a command decoding circuit, configured to decode the command, to obtain an internal command signal; a counter circuit, configured to count a clock cycle based on an initial clock signal, to generate a first counting signal and a second counting signal; and a clock signal interception circuit, connected to the command predecoding circuit, the command decoding circuit, and the counter circuit, and configured to intercept the initial clock signal based on the predecoded command signal, the internal command signal, the first counting signal, and the second counting signal, to obtain a target clock signal. According to embodiments of the present disclosure, a dynamic loss of the memory can be reduced.

Abstract: A photogrammetric ground control point quality evaluation method based on Monte Carlo test relates to the field of photogrammetry technology. Firstly, aerial photographs and ground control points from a survey area are obtained, the ground control points are numbered, the aerial photographs are performed with point-placing and aerial triangulation densification. Secondly, a Monte Carlo test experiment is designed, a certain number of the ground control points are selected as control points with the rest as check points, ensuring each ground control point as the control point a certain number of times, and average errors of the ground control points are calculated. Thirdly, average values of the average errors of the ground control points are calculated, standard deviations of the average errors of the ground control points are calculated. Finally, a quality coefficient Q of each ground control point is calculated and evaluated according to quality evaluation standards.

Abstract: An electric tool includes a motor, a drive shaft, a torque sensing module, and a control device. A control method of the electric tool includes: driving the motor to rotate a rotating shaft in a direction of rotation through the control device; driving the motor in a plurality of first start-stop cycles through the control device when the control device determines that an increase in the torque sensed by the torque sensing module; driving the motor in a plurality of second start-stop cycles through the control device when the control device determines that the torque sensed by the torque sensing module has increased to a first predetermined torque and is less than a second predetermined torque. Therefore, in the process of tightening or loosening a workpiece, the discomfort felt by the hands of the user due to reaction forces during increasing the torque could be effectively reduced.

Abstract: A three-section synchronous slide rail, which has simple structure, longer service life, is easy to install and replace is provided, which includes: two sets of slide rail assemblies which comprise a fixed rail, a middle rail and a sliding rail, synchronization components comprising a flexible deflector unit and a roller, the flexible deflector unit is connected with the fixed rail and the sliding rail, the middle rail is connected with a rope base, a first end of the flexible deflector unit is wound around a first end of the rope base and fixed to the rope base, and a second end of the flexible deflector unit bypasses the roller and is reversely wound on a second end of the rope base and the second end of the flexible deflector unit is fixed to the rope base, a connecting rod is connected between the rope bases.

Abstract: A vertical displacement stopping system includes a sliding guide mechanism, a locking mechanism and a bearing mechanism. The locking mechanism, having positioning holes, includes positioning pins, telescopic mechanisms, and a handle located at a front portion of the bearing mechanism, wherein the handle is connected with the positioning pins through transmission parts, respectively. Each of the telescopic mechanisms includes a housing having a chamber, a movable block located within the chamber, and a reset spring located between a top portion of the movable block and the housing, wherein each of the transmission parts is connected with each of the positioning pins through the movable block.

Abstract: An improved electric slide rail includes a motor driving device and two slide rail assemblies symmetrically arranged. Every slide rail assembly includes a slide rail and a fixed rail, wherein the slide rail is slidably sleeved on the fixed rail, a rack housing is sleeved on an outer side of the fixed rail, a rack is provided on the rack housing, a gear engaged with the rack is mounted on the slide rail; the motor driving device is installed on the slide rail through a fixing device and is electrically connected with a controller. The improved electric slide rail further includes a clutch which is electrically connected with the controller, wherein the clutch is arranged at a side where an output shaft of a motor of the motor driving device is provided, and is connected with the slide rail through a linkage structure.

Abstract: A ball bearing slide includes: two outer slides, an inner slide located in the outer slides, two ball cages, and ball rows rollably arranged in the ball cages and supported between the inner slide and the outer slides; wherein the inner slide includes two end parts and a connecting part connecting the two end parts; the ball rows are located between the end parts and the outer slides; the outer slides drive the ball rows to rotate in a pull-out direction and a push-in direction; wherein each of the end parts of the inner slide has a free end; the free end of at least one of the end parts projects towards a centerline of the certain ball row to form a stopping part. During operation, the stopping part prevents the ball rows from falling off from the inner slide under excessive force.

Abstract: A control method of an impact power tool includes: control a motor to rotate; continuously obtain a rotation speed signal based on a detecting result of a rotation speed detecting device and obtain a current signal based on a detecting result of a current detecting device; obtain a rotating time of each of rotation angles of the motor based on a variation of pulse waves of rotation speed signal and obtain the motor current based on the current signal; determine a number of impact that the impact mechanism produces based on a variation of the rotating time and a variation of the motor current; control the motor to stop rotating when the number of impact reaches a predetermined number. In this way, an output torque outputted by the impact power tool could be accurately controlled.

Abstract: The present invention provides a vertical displacement stopping system, which is able to facilitate the adjustment of the position of an object. The system includes a sliding guide mechanism, a locking mechanism and a bearing mechanism. The locking mechanism, having positioning holes, includes positioning pins, telescopic mechanisms, and a handle located at a front portion of the bearing mechanism, wherein the handle is connected with the positioning pins through transmission parts, respectively. Each of the telescopic mechanisms includes a housing having a chamber, a movable block located within the chamber, and a reset spring located between a top portion of the movable block and the housing, wherein each of the transmission parts is connected with each of the positioning pins through the movable block.

Abstract: An improved electric slide rail includes a motor driving device and two slide rail assemblies symmetrically arranged. Every slide rail assembly includes a slide rail (2, 28) and a fixed rail (31, 26), wherein the slide rail (2, 28) is slidably sleeved on the fixed rail (31, 26), a rack housing (1, 10) is sleeved on an outer side of the fixed rail (31, 26), a rack (13, 11) is provided on the rack housing (1, 10), a gear (4, 16) engaged with the rack (13, 11) is mounted on the slide rail (2, 28); the motor driving device is installed on the slide rail (2, 28) through a fixing device and is electrically connected with a controller. The improved electric slide rail further includes a clutch (18, 39, 46) which is electrically connected with the controller, wherein the clutch (18, 39, 46) is arranged at a side where an output shaft of a motor (17, 41, 44) of the motor driving device is provided, and is connected with the slide rail (2, 28) through a linkage structure.

Abstract: Disclosed are a stem cell generator, a construction method therefor and the use thereof. The stem cell generator is formed by implanting a biomaterial loaded with active substances and/or cells, or a biomaterial with an osteogenic induction capability into animal or human bodies and producing organoids upon development.

Abstract: Disclosed is a stem cell generator for the generation of organoids after the development of biological materials loaded with active substances which are implanted into an animal or a human body. The active substances are mesenchymal stem cells, bone morphogenetic protein-2 or bone morphogenesis protein-7, other growth factors/polypeptides or growth factors/polypeptide combinations having the ability of inducing bone regeneration, or combinations thereof. The stem cell generator contains various types of blood cells and hematopoietic progenitor/stem cells having complete functions. The produced stem cells are used for treating hematopoietic damage, and can treat bone marrow failure and leukemia caused by radiotherapy/chemotherapy.

Abstract: Disclosed is a new use of a stem cell generator in preparation of bone defect repair materials, wherein the stem cell generator is formed by implanting a biomaterial with osteogenic induction capability or a biomaterial loaded with active substances and/or cells into an animal or a human body and generating organoids after development, the active substances are bone morphogenetic protein-2, or bone morphogenetic protein-7, other growth factors/polypeptides having bone regeneration induction ability, growth factors/polypeptide combinations, or a combination thereof. The cells are bone marrow-derived mesenchymal stem cells, adipose-derived mesenchymal stem cells or other derived mesenchymal stem cells; other types of cells with osteogenic differentiation capability; cells that aid in osteogenic differentiation of mesenchymal stem cells, such as vascular endothelial cells and the like.

Abstract: A control method of an impact power tool includes: control a motor to rotate; continuously obtain a rotation speed signal based on a detecting result of a rotation speed detecting device and obtain a current signal based on a detecting result of a current detecting device; obtain a rotating time of each of rotation angles of the motor based on a variation of pulse waves of rotation speed signal and obtain the motor current based on the current signal; determine a number of impact that the impact mechanism produces based on a variation of the rotating time and a variation of the motor current; control the motor to stop rotating when the number of impact reaches a predetermined number. In this way, an output torque outputted by the impact power tool could be accurately controlled.

Abstract: A three-section synchronous slide rail, which has simple structure, longer service life, is easy to install and replace is provided, which includes: two sets of slide rail assemblies which comprise a fixed rail, a middle rail and a sliding rail, synchronization components comprising a flexible deflector unit and a roller, the flexible deflector unit is connected with the fixed rail and the sliding rail, the middle rail is connected with a rope base, a first end of the flexible deflector unit is wound around a first end of the rope base and fixed to the rope base, and a second end of the flexible deflector unit bypasses the roller and is reversely wound on a second end of the rope base and the second end of the flexible deflector unit is fixed to the rope base, a connecting rod is connected between the rope bases.