Abstract: A fuel cell system and a method for purge and removing water during its stop and start process, the system comprises a fuel cell stack, an air supply system connected to a cathode at a cathode side of the fuel cell stack, and a hydrogen supply system connected to an anode at an anode side of the fuel cell stack, the air supply system includes an air compressor, an air inlet tube, and an air outlet tube, the air outlet tube is connected to a low-oxygen gas storage tank through a manifold, and the low-oxygen gas storage tank is connected back to the hydrogen supply system through a circulating tube. The method expels standing water from the fuel cell stack using an air compressor to continuously supply air to both the anode side and the cathode side of the fuel cell stack, so as to further protect the stack.

Abstract: A flow field plate for a fuel cell, the flow field plate is provided with a plurality of fluid channels wherein at least one split block is provided between the fluid channels, at least one auxiliary microflow-channel is arranged in the split block, the microflow-channel changes flow rate and flow pressure of fluid at different sites along the fluid channel by having a depth and a width smaller than a depth and a width of the fluid channel at a confluent segment and also smaller than a depth and a width of the fluid channel at a diverging segment, so as to generate a pressure difference that forces fluid to flow into a diffusion layer. The flow field plate adjusts flow rate and pressure of fluid at different sites along the fluid channel, so as to transmit the reaction medium more effectively and removes generated water more effectively.

Abstract: A experimental device is specifically an annular water tank formed by a first arc-shaped water tank, a first special-shaped water tank, a second arc-shaped water tank and a second special-shaped water tank which are sequentially connected head to tail, and the outer perimeter is 70 m to 110 m, wherein the inner walls of both the first special-shaped water tank and the second special-shaped water tank are flat, both of the widths between the outer walls and the inner walls are gradually increased from the two ends to the middle, and water flow pushing equipment which are capable of enabling the maximum water flow velocity in the experimental device to reach a preset value are respectively placed in the first special-shaped water tank and the second special-shaped water tank.

Abstract: A experimental device is specifically an annular water tank formed by a first arc-shaped water tank, a first special-shaped water tank, a second arc-shaped water tank and a second special-shaped water tank which are sequentially connected head to tail, and the outer perimeter is 70 m to 110 m, wherein the inner walls of both the first special-shaped water tank and the second special-shaped water tank are flat, both of the widths between the outer walls and the inner walls are gradually increased from the two ends to the middle, and water flow pushing equipment which are capable of enabling the maximum water flow velocity in the experimental device to reach a preset value are respectively placed in the first special-shaped water tank and the second special-shaped water tank.

Abstract: A method for forming a medical instrument from a mono-crystalline shape memory alloy.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: Provided in the present invention is a solid catalyst component for use in olefin polymerisation, comprising Mg, Ti, a halogen, and at least one electron donor, the electron donor being a 2-substituted amino-phenyl ester compound selected from general formula (I). Also disclosed in the present invention are a catalyst comprising the solid catalyst component, and an application for the catalyst in olefin polymerisation, particularly in propylene polymerization. Also provided in the present invention is a high activity catalyst, said catalyst being able to obtain polypropylene of high isotacticity and wide molecular weight distribution, and not requiring an external electron donor to obtain high isotacticity polypropylene; during polymerization, Al/Ti and Al/Si are reduced, the polymerization time is lengthened, and high activity can still be maintained, suitable for producing low-ash polymers.

Abstract: An expandable introducer sheath for passage of implant delivery catheters, such as catheters for delivery of prosthetic heart valves. The expandable sheath balances the amounts, shapes and positions of various stiff and elastic structures in the sheath to selectively program the expandability and buckling stiffness of the sheath. The expandable sheath can include, for example, an expandable tubular layer that includes alternating stiff and elastic wall portions of a single radial thickness. The combination of stiff and elastic wall portions allow for torque and push strength to advance the expandable sheath while at the same time accommodating temporary expansion. The expandable sheath can also be reinforced with a tubular layer of braided fibers or a stent structure for additional strength. Other embodiments include selective use of slots or gaps at the distal end of a stiff wall portion to enhance expandability and distribute strain.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A connection assembly in a vehicle comprises a bracket including a sliding groove; and a connector including a base plate configured to be received in the sliding groove of the bracket. The base plate or an inner wall of the sliding groove has a raised portion and a through hole on the raised portion. At a locked position, the base plate is at least partially received in the sliding groove and contacts the inner wall of the sliding groove under a pressure via the raised portion.

Abstract: An expandable introducer sheath for passage of implant delivery catheters, such as catheters for delivery of prosthetic heart valves. The expandable sheath balances the amounts, shapes and positions of various stiff and elastic structures in the sheath to selectively program the expandability and buckling stiffness of the sheath. The expandable sheath can include, for example, an expandable tubular layer that includes alternating stiff and elastic wall portions of a single radial thickness. The combination of stiff and elastic wall portions allow for torque and push strength to advance the expandable sheath while at the same time accommodating temporary expansion. The expandable sheath can also be reinforced with a tubular layer of braided fibers or a stent structure for additional strength. Other embodiments include selective use of slots or gaps at the distal end of a stiff wall portion to enhance expandability and distribute strain.

Abstract: Provided is an alkoxy magnesium supported olefin polymerization catalyst component, comprising the reaction products of the following components: at least one alkoxy magnesium compound of Mg(OR1?)N(OR2?)2-N, at least one titanium compound of general formula Ti(OR)nX4-n, at least one ortho-phenylene diester electron donor compound a, and at least one diether electron donor compound b, wherein the molar ratio of a to b is 0.05 to 20. The catalyst component has an ultrahigh polymerization activity when used for olefin polymerization, and does not require the use of an external electron donor, but can also obtain a polymer with a high isotacticity, and the resulting polymer has a relatively wide molecular weight distribution and a relatively low ash content.

Abstract: A method for manufacturing a shape-set nonlinear non-superelastic file comprising the steps of: providing a superelastic file having a shaft and a file axis; providing a fixture including a file path being defined by one or more displacement members, the file path configured for receiving the shaft; inserting at least a portion of the shaft into the fixture along the file path, the portion of the shaft including a first portion of the shaft; contacting the first portion of the shaft with a first displacement member of the one or more displacement members such that the first portion of the shaft is displaced from the file axis thereby forming a first offset portion of the shaft; heating the portion of the shaft while inserted in the fixture to a temperature of at least about 350° C. to about 600° C.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A delivery sheath includes an outer tubular layer and an initially folded inner tubular layer. When an implant passes therethrough, the outer tubular layer expands and the inner tubular layer unfolds into an expanded lumen diameter. The sheath may also include selectively placed longitudinal support rods that mediate friction between the inner and outer tubular layers to facilitate easy expansion, thereby reducing the push force needed to advance the implant through the sheath's lumen.

Abstract: A method for manufacturing a nonlinear superelastic file comprising the steps of: providing a superelastic file having a shaft and a file axis; providing a fixture including a file groove being defined by one or more displacement members, the file groove configured for receiving the shaft; inserting at least a portion of the shaft into the fixture along the file groove, the portion of the shaft including a first portion of the shaft; contacting the first portion of the shaft with a first displacement member of the one or more displacement members such that the first portion of the shaft is displaced from the file axis thereby forming a first offset portion of the shaft; heating the portion of the shaft while inserted in the fixture to a temperature of at least about 300° C. for a time period of at least about 1 minute to shape-set the portion of the shaft thereby forming a shape-set nonlinear file.

Abstract: An expandable introducer sheath for passage of implant delivery catheters, such as catheters for delivery of prosthetic heart valves. The expandable sheath balances the amounts, shapes and positions of various stiff and elastic structures in the sheath to selectively program the expandability and buckling stiffness of the sheath. The expandable sheath can include, for example, an expandable tubular layer that includes alternating stiff and elastic wall portions of a single radial thickness. The combination of stiff and elastic wall portions allow for torque and push strength to advance the expandable sheath while at the same time accommodating temporary expansion. The expandable sheath can also be reinforced with a tubular layer of braided fibers or a stent structure for additional strength. Other embodiments include selective use of slots or gaps at the distal end of a stiff wall portion to enhance expandability and distribute strain.