Abstract: The present disclosure provides a purification method for 3-amino-5-methylpiperidine with amino protected by Boc. The method includes adding a solvent to the crude product of 3-amino-5-methylpiperidine with amino protected by Boc, heating until it is dissolved to obtain a mixed solution; adding an acid and an amine crystallization auxiliary to the mixed solution, stirring and dispersing to obtain a dispersed solution; cooling the dispersed solution until crystallization, separating and drying same to obtain a salt crystal of 3-amino-5-methylpiperidine with amino protected by Boc. The present disclosure improves the product characters of 3-amino-5-methylpiperidine with amino protected by Boc after salifying and crystallization, thereby improving the yield and purity of the product, at the same time, it simplifies the operation steps of salifying and crystallization of 3-amino-5-methylpiperidine with amino protected by Boc, shortens the operation time, and reduces production costs.

Abstract: Provided in the present disclosure are a nemonoxacin malate active pharmaceutical ingredient with low combination impurities, and a preparation method thereof, specifically, provided in the present disclosure is a method for preparing the nemonoxacin malate active pharmaceutical ingredient, the method includes the following steps: 1) providing a C1-C3 alcohol/water mixed solvent in which nemonoxacin free base (Formula II) and D,L-malic acid are dissolved; and 2) performing cooling crystallization on a mixed solution obtained in the step 1), and then performing solid-liquid separation, washing and drying on a precipitated solid, so as to obtain the nemonoxacin malate active pharmaceutical ingredient.

Abstract: The present invention provides a packaged condom comprising a sealed package and, within the package, a condom comprising natural rubber latex and/or synthetic polyisoprene, wherein the condom comprises, on one or more surfaces thereof and in contact with the natural rubber latex and/or synthetic polyisoprene, an aqueous lubricant. The aqueous lubricant comprises a thickener and, in a total amount of from 5 to 25% by weight of the lubricant, one or more organic compounds independently selected from the group consisting of a polyhydric alcohol and a sugar, each of said one or more organic compounds having at least 4 hydroxyl groups and a molecular weight of from 120 to 10000.

Abstract: A computing apparatus and method for proof of work, and a chip are provided. The computing apparatus includes: N selectors, respectively configured to obtain N groups of first input quantities; and N first compressors, respectively connected to the N selectors, and respectively configured to receive the N groups of first input quantities sent by the N selectors, and to receive a same second input quantity, wherein each first compressor is configured to sequentially perform compression processing on the second input quantity and each first input quantity in one group of first input quantities, and compression processing results of the N first compressors each is used to obtain a proof-of-work result.

Abstract: Provided in the present disclosure are a nemonoxacin malate active pharmaceutical ingredient with low combination impurities, and a preparation method thereof, specifically, provided in the present disclosure is a method for preparing the nemonoxacin malate active pharmaceutical ingredient, the method includes the following steps: 1) providing a C1-C3 alcohol/water mixed solvent in which nemonoxacin free base (Formula II) and D,L-malic acid are dissolved; and 2) performing cooling crystallization on a mixed solution obtained in the step 1), and then performing solid-liquid separation, washing and drying on a precipitated solid, so as to obtain the nemonoxacin malate active pharmaceutical ingredient.

Abstract: The present invention provides a method for preparing a chiral 4-aryl-?-amino acid derivative. The preparation method comprises hydrogenating an enamine compound having a structure as shown in Formula III in an organic solvent in the presence of a catalyst containing a transition metal and BIBOPs. The preparation method of the present invention uses a small amount of a selected asymmetric catalyst, and has a simple operation, mild reaction conditions, a high yield, a high stereoselectivity, and better industrial application and economic values.

Abstract: A device includes a first FET coupled between first and drive terminals, and is configured to turn on/off responsive to a PWM signal having a first/second state, respectively. A second FET is coupled between the first and drive terminals and is configured to turn on responsive to the PWM signal having the first state, and turn off responsive to expiration of a particular delay after the second FET turns on. A third FET is coupled between drive and second terminals, and is configured to turn on/off responsive to the PWM signal having the second/first state, respectively. A fourth FET is coupled between the drive and second terminals, and is configured to turn on responsive to the PWM signal having the second state if a switching terminal has a first voltage, and turn off responsive to the PWM signal having the first state or the switching terminal having a second voltage.

Abstract: A system includes an input voltage node configured to provide an input voltage (VIN). The system also includes a load (RLOAD) and a switching converter coupled between the input voltage node and the load (RLOAD). The switching converter is configured to provide an output voltage (VOUT) to the load (RLOAD) based on the input voltage (VIN). The switching converter includes gate driver circuitry and a current mode control circuit coupled to the gate driver circuitry. The current mode control circuit is configured to output control signals to the gate driver circuitry in accordance with different modes of operation, wherein the current mode control circuit is configured to adjust a threshold (IPSM*) used to switch between a discontinuous conduction mode (DCM) and a power save mode (PSM).

Abstract: A device includes a first FET coupled between first and drive terminals, and is configured to turn on/off responsive to a PWM signal having a first/second state, respectively. A second FET is coupled between the first and drive terminals and is configured to turn on responsive to the PWM signal having the first state, and turn off responsive to expiration of a particular delay after the second FET turns on. A third FET is coupled between drive and second terminals, and is configured to turn on/off responsive to the PWM signal having the second/first state, respectively. A fourth FET is coupled between the drive and second terminals, and is configured to turn on responsive to the PWM signal having the second state if a switching terminal has a first voltage, and turn off responsive to the PWM signal having the first state or the switching terminal having a second voltage.

Abstract: A system includes an input voltage node configured to provide an input voltage (VIN). The system also includes a load (RLOAD) and a switching converter coupled between the input voltage node and the load (RLOAD). The switching converter is configured to provide an output voltage (VOUT) to the load (RLOAD) based on the input voltage (VIN). The switching converter includes gate driver circuitry and a current mode control circuit coupled to the gate driver circuitry. The current mode control circuit is configured to output control signals to the gate driver circuitry in accordance with different modes of operation, wherein the current mode control circuit is configured to adjust a threshold (IPSM*) used to switch between a discontinuous conduction mode (DCM) and a power save mode (PSM).

Abstract: A VR system, a wearable apparatus and a method for controlling a VR apparatus are disclosed. The wearable apparatus comprises a communication circuit, a processor, and a touch screen which are connected to one another successively; the communication circuit establishes a connection to the processor, and is configured to acquire control request information; the processor displays a control interface on the touch screen based on the control request information, generates control information based on touch actions performed on the control interface, and further sends the control information to the VR apparatus to control the VR apparatus via the control information. In this way, the present application may improve the user experience.

Abstract: A VR system, a wearable apparatus and a method for controlling a VR apparatus are disclosed. The wearable apparatus comprises a communication circuit, a processor, and a touch screen which are connected to one another successively; the communication circuit establishes a connection to the processor, and is configured to acquire control request information; the processor displays a control interface on the touch screen based on the control request information, generates control information based on touch actions performed on the control interface, and further sends the control information to the VR apparatus to control the VR apparatus via the control information. In this way, the present application may improve the user experience.

Abstract: A flipping installation device for LED strip lighting includes an installation frame, a house, at least one link mechanism, and at least one clamping mechanism. Each of the at least one link mechanism includes a first link mounted on the installation frame, a second link disposed on the house, and a third link rotatably connected between the first and second links. The first and second and third links is perpendicular to each other in the cross section perpendicular to the axial direction of the house when the house has been installed into the installation frame. Each of the at least one clamping mechanism includes a catch head disposed on the installation frame, and a resilient lock disposed on the house and coupled to the catch head. The link mechanism and the clamping mechanism are located on the opposite side of the house.

Abstract: A flipping installation device for LED strip lighting includes an installation frame, a house, at least one link mechanism, and at least one clamping mechanism. Each of the at least one link mechanism includes a first link mounted on the installation frame, a second link disposed on the house, and a third link rotatably connected between the first and second links. The first and second and third links is perpendicular to each other in the cross section perpendicular to the axial direction of the house when the house has been installed into the installation frame. Each of the at least one clamping mechanism includes a catch head disposed on the installation frame, and a resilient lock disposed on the house and coupled to the catch head. The link mechanism and the clamping mechanism are located on the opposite side of the house.