34results about How to "Uniform ablation" patented technology

A catheter assembly for treatment of cardiac arrhythmia. The catheter assembly includes a catheter body and an ablative energy source. The catheter body includes a proximal portion, an intermediate portion, and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and includes an ablation section and a tip. The ablation section forms a loop defining a diameter greater than an outer dimension of a pulmonary vein ostium. The tip extends distally from the ablation section and is configured to locate a pulmonary vein. Finally, the ablative energy source is associated with the ablation section. With this configuration, upon activation of the energy source, the ablation section ablates a desired lesion pattern. In one preferred embodiment, the ablation section forms a distally decreasing radius helix, whereas the tip includes a relatively linear leader section. With this one preferred configuration, the tip readily locates a pulmonary vein and guides the ablation section to a seated relationship about a pulmonary vein ostium (or extra-ostial).

The invention relates to a multi-stage magnetic field straight pipe magnetic filtration and pulsed bias compounded electrical arc ion plating method, and belongs to the technical field of material surface treatments. In the prior art, plasma transmission efficiency is low and pulsed bias can not completely remove large particles due to applying of magnetic filtration on an arc source. A purpose of the present invention is to solve problems in the prior art. The method comprises: 1, connecting a workpiece to a pulsed bias power supply, connecting an electrical arc ion plating target source to a target power supply, and connecting a multi-stage magnetic field straight pipe magnetic filtration device in front of the target source; 2, carrying out thin film deposition, wherein work gas is introduced until achieving 0.01-10 Pa when a pressure in a vacuum chamber is less than 10<-2> Pa, the pulsed bias power supply is opened, a pulsed bias amplitude value, frequency and a duty ratio are adjusted, the target power supply is opened, plasma is generated, the multi-stage magnetic field straight pipe magnetic filtration device is opened, removal of large particles and efficient transmission of the plasma in the magnetic filtration device are achieved, process parameters are adjusted, and a thin film with no large particle defect is rapidly produced; and 3, adopting a single-stage magnetic field to combine direct current/pulsed bias to obtain a thin film with a certain thickness.

The invention relates to a preparation method of a MCrAlY high temperature protection coating. The preparation method sequentially comprises the following steps that before plating, a base material is subject to surface scale removal and washing treatment; after vacuumizing is carried out to 5.0*10<-3> Pa, the in-furnace pressure intensity is 1.0 Pa to 3.0 Pa, the Ar gas flow is 200 sccm to 600 sccm, the back bias voltage is 500 V to 1000 V, the time is 30 min to 60 min, and glow discharge ion washing is carried out; and deposition of the MCrAlY coating is carried out, wherein the in-furnace pressure intensity is 0.8 Pa to 2.0 Pa, the Ar gas flow is 300 sccm to 500 sccm, the arc target current is 60 A to 120 A, according electromagnetic parameters, the voltage is 8 V to 50 V, the frequency is 1.0 Hz to 33.3 Hz, the permanent magnet parameter is 5000 Gs to 15000Gs, and the back bias voltage is 50 V to 200 V. According to the method, the protection coating which is good in film/base bonding force, compact in film layer, small in surface roughness, resistant to high temperature oxidation and excellent in heat corrosion resistance can be prepared on the high temperature alloy surface. The method can solve the problem that traditional arc ion plating target using rate is low, the aggregation state arc spot drop large particles are achieved, and the method is suitable for industrial production.

A thermal accelerant is delivered to a tissue site and localized to modulate the shape, extent or other characteristic of RF or microwave-induced hyperthermic tissue ablation. The accelerant may be provided via an image-guided hand piece or via a lumen added to a microwave antenna, and promotes faster heating, more complete ablation and/or a more extensive treatment region to reduce recurrence of treated cancers, overcoming natural limitations, variations in tissue response and drop-off or thermal loss away from the antenna. The accelerant is delivered as a low-viscosity but heat sensitive fluid, and is fixed in place to provide regions of preferential absorption or heating. Shorter exposure times to heat the far field may allow survival of vulnerable tissue such as vessels, and multiple antennae may be used for effective treatment of irregular or large tumors.

The invention discloses a subsonic-speed ladle cover ablation test device under high-entropy condition. The device comprises a ladle cover spraying pipe, a throat way support rod, a transfer flange, atransfer section and a model bracket. The ladle cover spraying pipe and the model bracket are fixed on the transfer flange. The throat way support rod is connected with the model bracket by the transfer section; and a throat way part of the throat way support rod is positioned in the ladle cover spraying pipe. The overlap with the center axis of the ladle cover spraying pipe is guaranteed throughconnection between the throat way support rod and the transfer section. During testing, a test model is mounted on the throat way support rod, an annular channel between the outer surface of the testmodel and the inner surface of the ladle cover spraying pipe is a high-entropy airflow channel, and the flowing of air currents in the ladle cover spraying pipe is subsonic-speed flowing. The devicecan be applied to aerospace pneumatic thermal protection ground simulation tests in high-entropy airflow state.

The present invention is pulse laser deposition (PLD) process for preparing p-type compound CuAlS2 in chalcopyrite structure and transparent doped conducting film. The PLD process prepares p-type compound CuAlS2 or doped film on the substrate of quartz glass, common glass or Si chip by using the compound block obtained through solid phase reaction and SPS sintering or no-pressure sintering as the target and under proper conditions of atmospheric pressure, substrate temperature, and laser strength and frequency. The prepared CuAlS2 film has p-type conductivity, high conductivity, high visible light transparency and other excellent optoelectronic performance, and may find its broad application foreground in electronics and optoelectronics.

The invention provides an adjustable rotating magnetic field vacuum explosion chamber. The adjustable rotating magnetic field vacuum explosion chamber comprises a pair of conductive rods, a shielding cover, a pair of disk shaped contacts, an insulation casing, a rotating magnetic field generation device and an amplitude and frequency adjustment device, wherein the insulation casing is arranged at an outer side of the shielding cover, the rotating magnetic field generation device is fixed outside the insulation casing, the rotating magnetic field generation device and the disk shaped contacts are coaxially arranged, the amplitude and frequency adjustment device is connected with the rotating magnetic field generation device, a magnetic field generated by the rotating magnetic field generation device is adjusted, the conductive rod is connected with the disk shaped contacts, and the disk shaped contacts are coaxially and oppositely arranged in the shielding cover. The adjustable rotating magnetic field vacuum explosion chamber is advantaged in that the rotating magnetic field generation device is completely disposed outside the insulation casing of the explosion chamber, gas generation possibility is avoided, the generated transverse magnetic field is more concentrated between the contacts, namely the arc portion, and closing and opening of the contacts are further facilitated.

The invention relates to a two-electrode gas switch. The two-electrode gas switch comprises a first electrode base, a second electrode base, and two electrodes which are used for forming electrode gaps. The first electrode base is tubular. The electrode gaps are arranged in the internal cavity of the first electrode base. The radial side wall of the first electrode base is provided with a conductive connection structure which is used for enabling the first electrode base to be conductively connected with an external object. The conductive connection structure is arranged at one side, which is close to the second electrode base, of the electrode gaps in the axial direction of the first electrode base. The direction of current flowing through the radial side wall of the first electrode base is opposite to the direction of current flowing through the electrode gaps when current flows. The electromagnetic force generated by current flowing through the radial side wall of the first electrode base affects on the discharge arcs of the two electrode gaps to generate hooping constraint force on the discharge arcs of the two electrode gaps so that heat, the arcs and graphite particles are enabled to be concentrated, more graphite particles are enabled to be oxidized into gas, pollution of the graphite particles to insulating cylinders can be reduced and the service life of the switch can be prolonged.

The invention discloses a shaving blade with a multi-layer strengthening coating and a preparation method of the shaving blade. A blade base with a blade edge is prepared by adopting a composite technology of magnetic filtration cathode vacuum arc deposition and MEVVA source injection, and a strengthening layer and a lubricating layer are arranged on the blade base, wherein the strengthening layeris composed of a plurality of nanometer layers with different hardness and comprises a Ti transition layer, a TiN transition layer and a Ti-doped DLC layer which are sequentially arranged from insideto outside, and the lubricating layer is a polytetrafluoroethylene layer. Multiple transition layers such as the Ti transition layer and the TiN transition layer are introduced between the blade basematerial and the DLC film layer, meanwhile, Ti ions are injected into MEVVA source ions, the surface hardness of a shaver can be enhanced, the interface lattice effect can be optimized, the internalstress of the coating can be effectively relieved, the bonding force between the coating and the base is effectively improved, the workpiece hardness and wear resistance are improved, and the frictioncoefficient is reduced so that the service life of the workpiece can be prolonged.

The invention discloses a device for removing eye bulged fat. The device comprises a central controller (6), a cooling fluid control part (3), a heating control part (4), a radio frequency control part (5) and a radio frequency handle (1), wherein the central controller (6) is connected with the cooling fluid control part (3), the heating control part (4), the radio frequency handle (1) and the radio frequency control part (5), and is used for receiving a booking program and a temperature feedback signal of a temperature sensor (133) on the radio frequency handle (1); and according to the requirement of the booking program and the temperature feedback signal, corresponding control instructions for a cooling fluid, a heating component and a radio frequency signal are respectively sent to the cooling fluid control part (3), the heating control part (4) and the radio frequency control part (5) so as to control the corresponding components.

The invention discloses a bipolar multi-mode micro-cathode arc thruster. The bipolar multi-mode micro-cathode arc thruster is characterized by comprising an insulating cylindrical shell (1), an insulating plate (2), a coaxial anode (3), a hollow coaxial insulating member (4), an annular cathode (5), an annular anode (6), an annular insulating member (7), an electromagnetic coil (8) and a permanentmagnet (9). The double-anode structure of the bipolar multi-mode micro-cathode arc thruster has two anode structures with different configurations, namely the coaxial anode and the annular anode, andthe coaxial anode and the annular anode can be switched to run along with the change of the operating life of the thruster, so that the working states of the two modes in the life period of the thruster are achieved.

The invention discloses a four-electrode self-triggering steepening gas switch which is characterized in that an upper electrode is arranged at the upper part of an insulating sleeve, an upper intermediate electrode sleeves the upper electrode, an upper insulating flange is arranged between the upper electrode and the upper intermediate electrode, and sealing gaskets are respectively arranged between the upper insulating flange and the upper electrode and between the upper insulating flange and the upper intermediate electrode; a lower electrode corresponding to the upper electrode is arranged at the lower part of the insulating sleeve, a lower intermediate electrode sleeves the lower electrode, a lower insulating flange is arranged between the lower electrode and the lower intermediate electrode, and sealing gaskets are respectively arranged between the lower insulating flange and the lower intermediate electrode and between the lower insulating flange and the lower electrode; and an air inlet is formed in one side of the insulating sleeve, and an air outlet is formed in the other side correspondingly. According to the four-electrode self-triggering steepening gas switch, the gap of the two intermediate electrodes is firstly broken down to further assist the breakdown of a main gap, the breakdown between the electrodes does not ablate the internal insulating material, the switch can operate in a repetition frequency mode, the switch is stable in working property and long in service life, the structure is compact, and the conduction inductance is low.