Abstract: This disclosure generally relates to power generation methods and systems based on gas turbine engines, and particularly to mobile and adaptive power generation systems and methods based on gas turbine engine for supplying mechanical and/or electrical power for fracturing operations at an oil wellsite. Various systems, platforms, components, devices, and methods are provided for flexibly and adaptively configure one of more gas turbines, hydraulic pumps, and electric generators to support both fracturing and electric demands at a well site. The disclosed implementations enable and facilitate a mobile, adaptive, and reconfigurable power system to provide both mechanical and electric power for hydraulic fracturing operation, which is convenient to set up for operation and for transport.

Abstract: A DC-DC power converter employs a full bridge series resonant converter topology with a resonant tank and two transformers, one before and one after the resonant tank, to obtain a high voltage (e.g., approximately 300V, approximately 1500V or greater) output from a relatively low voltage (e.g., approximately 9V-16V) input, for instance an input from one or more battery cells. DC-DC power converter is operable to output high voltage (e.g., around 300V, 1500V or higher) short duration pulses (e.g., tens of nanoseconds or less). A burst mode control technique provides as good regulation characteristics at light loads. Instead of turning OFF the active switches during an OFF period, the switches are operated at a different frequency (e.g., higher frequency) during the OFF period than a frequency at which the switches are turned ON during the ON period. Auxiliary loads can also be supplied.

Abstract: A cutting element may include a body, a concave cutting face formed at a first end of the body, the cutting face including one or more cutting ridges adjacent a cutting tip that are raised above the concavity of the cutting face and having a length that is at least about 10% of a diameter of the cutting face. An edge is formed around a perimeter of the cutting face, and the edge has an edge angle defined between a tangent of the cutting face and a cylindrical side surface of the body, the edge angle being acute at the cutting tip and varying around the perimeter of the cutting face.

Abstract: The present disclosure relates to a switching converter and its control circuit. The control circuit includes an error amplifier, a transient-response compensation circuit and a PWM comparator. The transient-response compensation circuit is coupled to an output terminal of the error amplifier for increasing a differential current of the error amplifier to increase the rate of output change of the error amplifier in a case that a voltage difference between the first feedback signal and the reference voltage exceeds a predetermined threshold. The output voltage can be prevented from having too high or too low fluctuations when a load changes, thereby improving transient response characteristics of the power converter, and optimizing dynamic characteristics of the power converter over a wide range of the fluctuation of the load in a continuous operation mode.

Abstract: A Boost-type converter and a driving circuit for driving a high-side switching transistor thereof includes an input voltage sensing unit, an oscillator, a logic unit, and a high-side driving unit. The logic unit receives an input voltage detection signal, a clock signal and a pulse width modulated signal, and generates a control signal according to the input voltage detection signal, the clock signal and the pulse width modulated signal. The high-side driving unit generates a driving signal of a high-side switching transistor for driving the high side switching transistor according to the control signal. When the input voltage is greater than a predetermined voltage, the high-side driving unit controls the high-side switching transistor to be in a weak-conduction state or off state for a time period of an inductor current discharge phase.

Abstract: Systems and methods for obfuscating keyboard keys against interception are provided. In an example, a protected application is dynamically virtualized in user space, wherein the virtualization comprises an isolated keyboard path. Keystrokes are injected to the isolated keyboard path, wherein the injected keystrokes are associated with a respective timestamp, and user input keystrokes are obfuscated with the injected keystrokes and the obfuscated keystrokes are passed to a low level hook. The obfuscated keystrokes passed to the low level hook are separated according to tags associated with the obfuscated keystrokes to obtain the user input keystrokes. The user input keystrokes are transmitted to a target window of the protected application.

Abstract: A method includes determining a first data sending rate based on multiple round-trip times (RTTs), where the multiple RTTs include RTTs of a plurality of first probe packets sent at different sending rates, and the first sending rate is a sending rate corresponding to an RTT that is in the multiple RTTs and that is less than a first preset threshold; determining a second sending rate based on a plurality of packet loss rates, where the packet loss rates include packet loss rates of a plurality of second probe packets sent at different sending rates, and the second sending rate is a sending rate corresponding to a packet loss rate that is less than a second preset threshold; and sending a third probe packet at a third sending rate.

Abstract: A test device for rigid-flexible characteristics of a rigid-flexible transition overhead conductor rail, includes a movable vehicle moved in a length extending direction of the overhead conductor rail. A telescopic mechanism for providing lifting force for the overhead conductor rail is mounted on the movable vehicle and stretches out and draws back in a vertical direction, and a conversion plate is connected to a top end of the telescopic mechanism and synchronously moved in the vertical direction therewith. A sliding assembly is mounted at a top of the conversion plate and slides along the overhead conductor rail with the movable vehicle. The overhead conductor rail is located over the sliding assembly which abuts against a bottom wall of the overhead conductor rail. A force sensor is arranged between the telescopic mechanism and the conversion plate. A displacement detection mechanism is arranged on the conversion plate.

Abstract: Provided are a display apparatus and a process method for the display apparatus. The display apparatus includes a display; a communicator, communicating with the network; a remote controller; a memory; and a processor configured for executing instructions in the memory to cause the display apparatus to perform: obtaining video source information from a target video source currently played by the display, where the video source information includes signal source information and type information; determining picture modes corresponding to the target video source according to the signal source information and the type information; displaying the picture modes corresponding to the target video source in a picture mode list; in response to a selection instruction for selecting a target picture mode, obtaining image adjustment parameters corresponding to the target picture mode; and adjusting image quality of the target video source according to the image adjustment parameters.

Abstract: A multi-axis turntable includes a base, a rocker arm and a first driving device capable of driving the rocker arm to rock around the first rotation axis on the base. A swing arm and a second driving device, which is capable of driving the swing arm to swing around the second rotation axis on the rocker arm, are provided on the rocker arm. A workbench and a third driving device for driving the workbench to rotate around the third rotation axis are provided on the swing arm. The second rotation axis and the third rotation axis are parallel to each other or on different planes. Compared with the existing double rotating shaft turntable, the multi-axis turntable of the present invention has a cutting tool system of good and stable rigidity.

Abstract: A power generation apparatus and a power system are provided. The power generation apparatus includes a first transportation means, a gas turbine and a generator, the first transportation means has a first platform, a first housing is provided on the first platform, the gas turbine is arranged in the first housing and has a first input terminal and a first output terminal, the generator is arranged in the first housing and has a second input terminal and a second output terminal, the first output terminal is connected with the second input terminal.

Abstract: Provided are a display apparatus and a process method for the display apparatus. The display apparatus includes a display; a communicator, communicating with the network; a remote controller; a memory; and a processor configured for executing instructions in the memory to cause the display apparatus to perform: obtaining video source information from a target video source currently played by the display, where the video source information includes signal source information and type information; determining picture modes corresponding to the target video source according to the signal source information and the type information; displaying the picture modes corresponding to the target video source in a picture mode list; in response to a selection instruction for selecting a target picture mode, obtaining image adjustment parameters corresponding to the target picture mode; and adjusting image quality of the target video source according to the image adjustment parameters.

Abstract: The present disclosure provides a yeast mannan-oligosaccharide, a preparation method and a use thereof. The preparation method comprises the following steps: step S1, mixing the yeast cell wall with water to obtain a mixed solution; step S2, adjusting the pH of the mixed solution to 4-9, and carrying out a first enzymolysis with a protease to form a first enzymatic hydrolysate; secondly, subjecting the first enzymatic hydrolysate to a second enzymolysis with a polysaccharidase to obtain a second enzymatic hydrolysate; and step S3, subjecting the second enzymatic hydrolysate to centrifugal separation so as to obtain a supernatant and a centrifugal heavy phase, filtering the supernatant with an ultrafiltration membrane, the retentate being the yeast mannan-oligosaccharide, the permeate being the yeast extract, and the centrifugal heavy phase being the yeast glucan.

Abstract: An LED panel structure includes a PCB board and a plurality of LEDs. The PCB board is provided with a plurality of data lines, a plurality of scanning lines and a plurality of via holes. The data lines and the scanning lines are respectively located at different layers of the PCB board. The LEDs are disposed on the PCB board to form LED rows and LED columns, each LED column includes a plurality of LED groups, and each LED group includes two adjacent LEDs. A plurality of adjacent LEDs are sequentially arranged in a second direction to form light-emitting pixels. The LED includes a common-electrode terminal and a non-common-electrode terminal. All common-electrode terminals in each LED column are connected to one scanning line through via holes. All non-common-electrode terminals in each LED row are connected to one data line. Two data lines are provided between adjacent LED groups.

Abstract: An LED arrangement structure is provided with a plurality of LEDs arranged in an array in the first direction and the second direction to form a plurality of LED rows and a plurality of LED columns, each of the LED rows includes a plurality of LED groups, and each of the LED groups includes two adjacent LEDs. Two non-common-electrode terminals in each of LED groups in at least one of the LED rows are connected to each other on a surface layer of the PCB board.

Abstract: In an embodiment, a source node assigns a first number to a probe data packet in a probe data flow in a sending sequence, where the first number is used to select a transmission path for the probe data packet. The source node sends the probe data packet in the probe data flow to a destination node at a first sending rate. Each time the source node receives a probe data packet backhauled by the destination node, the source node sends a service data packet in a service data flow, where the service data packet is assigned a second number corresponding to the probe data packet, and the second number is used to select a transmission path for the service data packet.

Abstract: This disclosure generally relates to power generation methods and systems based on gas turbine engines, and particularly to mobile and adaptive power generation systems and methods based on gas turbine engine for supplying mechanical and/or electrical power for fracturing operations at an oil wellsite. Various systems, platforms, components, devices, and methods are provided for flexibly and adaptively configure one of more gas turbines, hydraulic pumps, and electric generators to support both fracturing and electric demands at a well site. The disclosed implementations enable and facilitate a mobile, adaptive, and reconfigurable power system to provide both mechanical and electric power for hydraulic fracturing operation.

Abstract: This disclosure generally relates to power generation methods and systems based on gas turbine engines, and particularly to mobile and adaptive power generation systems and methods based on gas turbine engine for supplying mechanical and/or electrical power for fracturing operations at an oil wellsite. Various systems, platforms, components, devices, and methods are provided for flexibly and adaptively configure one of more gas turbines, hydraulic pumps, and electric generators to support both fracturing and electric demands at a well site. The disclosed implementations enable and facilitate a mobile, adaptive, and reconfigurable power system to provide both mechanical and electric power for hydraulic fracturing operation.

Abstract: Embodiments of this application disclose a data transmission method and a communication apparatus. The method may be applied to a data transmission or data distribution scenario in a peer-to-peer P2P network. The method includes: A first end node sends delayed transmission information to a second end node, where the delayed transmission information indicates time information at which the first end node delays sending first data to the second end node. When determining that the second end node accepts the delayed transmission information, the first end node delays sending the first data to the second end node, to alleviate a load of the first end node, so that a network congestion problem caused by a large-scale concurrent data request can be resolved.