Abstract: The invention provides a test method for quantitatively studying a stress wave propagation law of a porous rock, which adopts a dynamic true triaxial electromagnetic Hopkinson bar test system for testing. The test method comprises: quantitatively designing and preparing a cubic porous rock sample required by testing; placing the cubic pore rock sample in a central cubic square chest; and quantitatively studying a high-amplitude stress wave propagation law of the porous rock on the cubic porous rock sample by adopting the dynamic true triaxial electromagnetic Hopkinson bar test system.

Abstract: Provided is a fixture applied to sticking a strain gauge on a Hopkinson square bar and a use method of the fixture. The invention is specially designed for a square waveguide bar, and the fixture further ensures consistency of the same group of strain gauges along a cross-section position of the bar. The fixture has important practical value in application in a dynamic true triaxial electromagnetic Hopkinson bar test, especially in a high-end material testing field requiring high-precision and high-reliability test data.

Abstract: Provided are an energy absorbing and buffering device applied to a dynamic true triaxial electromagnetic Hopkinson bar and a testing and using method thereof. The device comprises an energy absorbing and buffering ring, an exhaust pipe and an inert gas storage bin. According to the testing and using method, the energy absorbing and buffering device is utilized and connected with a waveguide bar through a middle hollow structure; and a rear end of the energy absorbing and buffering ring is tightly attached to a baffle at a confining pressure loading end. The energy absorbing and buffering device provides energy absorbing and buffering for the waveguide bar, which prolongs a service life of the waveguide bar under an impact load.

Abstract: Provided are an energy absorbing and buffering device applied to a dynamic true triaxial electromagnetic Hopkinson bar and a testing and using method thereof. The device comprises an energy absorbing and buffering ring, an exhaust pipe and an inert gas storage bin. According to the testing and using method, the energy absorbing and buffering device is utilized and connected with a waveguide bar through a middle hollow structure; and a rear end of the energy absorbing and buffering ring is tightly attached to a baffle at a confining pressure loading end. The energy absorbing and buffering device provides energy absorbing and buffering for the waveguide bar, which prolongs a service life of the waveguide bar under an impact load.

Abstract: A system for determining dental caries in a patient's tooth, the system including a dental tray including a curved channel configured to be placed on the patient's teeth on the patient's lower jaw or below the patient's teeth on the patient's upper jaw, the channel includes a length, two side walls and a middle wall connecting the two side walls, and a U-shaped excitation-detection transducer defined by two side portions and a middle portion connecting the two side portions, the transducer configured to be supported on and slidingly coupled with the channel with a shape of the transducer conforming to a cross-sectional periphery of the channel, the transducer selectively positioned over a portion of the channel over the patient's tooth, wherein the transducer is used to excite surface acoustic waves (SAWs) in the tooth and to receive SAWs in the patient's tooth.

Abstract: Provided is a dynamic true triaxial electromagnetic Hopkinson bar leveling and centering system and method. The system comprises a supporting base, a micrometer adjusting knob, a sliding platform, an auxiliary supporting plate, a fixing groove, at least two auxiliary centering targets and a lamp source. According to the auxiliary centering system, a principle that light rays are straight lines and two points form one line is adopted, and adjacent perpendicularity and coaxial centering leveling of a bar piece are determined by respectively adjusting a center of a loading end surface of the bar piece and an upper surface of the bar piece.

Abstract: Provided is a stress blank angle eliminating device and method for a dynamic true triaxial electromagnetic Hopkinson bar. Objectives of eliminating influence of a stress blank angle in a sample in a test and preventing permanent deformation caused by mutual collision between the Hopkinson bars are achieved. The adjustable test device for eliminating the stress blank angle eliminates influence of the stress blank angle generated by the sample in a triaxial six-direction dynamic impact test process, and is convenient for obtaining real dynamic failure parameters of the sample.

Abstract: The invention discloses an integrated deep purification device for removing sulfur, nitrate, dust and fluorine. The core component of the device is a purification system; the purification system comprises a headstock, a container and a purification system which are connected with the back of the headstock, and the purification system is arranged in the container, and comprises a purification tower I and a purification tower II, wherein the purification tower I comprises a tower body I, corona electrodes I and conductive filters; the purification tower II comprises a tower body II, corona electrodes II, a sprinkler system and electrofiltration coupling units.