Abstract:
Disclosed is a device for detecting orientation of a radioactive material to determine presence and position of the radioactive material, comprising: at least one first radiation detector; at least one second radiation detector, each of said at least one second radiation detector and each of said at least one first radiation detector being arranged side by side and in pairs, detection surfaces of said first and second radiation detector being in the same plane to receive radiation from the same direction in the same manner and to generate a first detection signal and a second detection signal, respectively; a shielding plate, said shielding plate being arranged between said first radiation detector and said second radiation detector arranged in a pair and extending forward beyond said detection surfaces; and a determination device for receiving the first and second detection signals from said first and second radiation detector, and determining whether a radioactive material exists or not according to said first and second detection signals and simultaneously determining the orientation of the radioactive material according to the difference between said first detection signal and said second detection signal. Also disclosed is a method for detecting orientation of a radioactive material.
Abstract:
The invention provides a multichannel analyzer for use in a multichannel spectrometer, which comprises a standard spectrum calibrator for obtaining energy calibration parameters of said multichannel spectrometer; an environment background spectrum calibrator for obtaining parameters of a current and a previous environment background spectrum; a peak shift detector for analyzing the parameters of the current and previous environment background spectrum to determine whether a peak shift occurs between them and to determine a correction coefficient of the peak shift; and a parameter corrector for correcting the energy calibration parameters of said multichannel spectrometer using said peak shift correction coefficient. The invention also provides a method for correcting a peak shift of a multichannel spectrometer adapted in the multichannel analyzer. The method for correcting and the multichannel analyzer can correct and monitor the peak shift of the multichannel spectrometer in real time.
Abstract:
A cleaner apparatus for use in a dental prophylaxis process includes an applicator defining a curved occlusal wall, a buccal wall, a lingual wall, and a distal wall, each of the buccal wall, the lingual wall and distal walls extending outwardly from the occlusal wall and forming a curved applicator configured to receive a patient's teeth in one of the maxillary arch and mandibular arch of the patient. The applicator being configured to receive and contain a cleaning agent in the cavity during a teeth cleaning process. An ultrasonic transducer is embedded within each of the buccal wall and the lingual wall of the applicator. A controller is electrically coupled to the transducers for powering the transducers and controlling the operation thereof, and the cleaner apparatus for cleaning a full arch of a patients teeth via cavitation of the cleaning agent resulting from ultrasonic radiation transmitted from the transducers.
Abstract:
An Alternate Current (AC) white Light-Emitting Diode (LED) device is provided, which belongs to the technical field of white LED manufacturing. The problem to be solved by the present invention is to low-costly overcome a series of deficiencies such as the stroboflash of an AC driven LED, and the heat dissipation difficulty caused by an integrated packaging of multiple LEDs. A white LED unit includes an LED chip and a light emitting material that can emit light when being excited by the LED chip. The luminous lifetime of the light emitting material is 1-100 ms. The LED chip only comprises one PN junction. The light emitted by the LED chip is mixed with the light emitted by the light emitting material to form white light. The white LED unit is driven by AC with a frequency not more than 100 Hz. The white LED device of prevent invention uses the single PN junction chip, rather than the prior integrated packaged AC multi-LED chip.
Abstract:
An alternating current (AC) white LED lighting device and a method for manufacturing the same are provided. The AC white LED lighting device consists of blue, violet or ultraviolet LED chips, blue afterglow luminescence materials A and yellow luminescence materials B. Wherein the weight ratio of the blue afterglow luminescence materials A to the yellow luminescence materials B is 10-70 wt %:30-90 wt %. Because of using afterglow luminescence materials, the light will be sustained when an excitation light source disappears, which can eliminate the influence of LED chips light output variation due to the AC fluctuation on the lighting device. And the problem of the heating of the chips also can be overcome. At the same time, the influence of temperature quenching effect and direction change of the AC current on the AC white LED lighting device is eliminated.
Abstract:
A method of assembling composite structures from objects in fluid includes providing a plurality of objects, each having a preselected size, shape, and spatial distribution of surface structural features characterizing a surface roughness; dispersing the objects into the fluid; and introducing a depletion agent. The depletion agent includes a plurality of particles having a size distribution preselected causing an attractive force arising from a depletion attraction between at least a first object and second object of the plurality in at least one relative position and orientation based on the preselected spatial distribution of surface structural features on the first and second objects, and the depletion attraction between the first and second objects forms at least one rigid bond or slippery bond at or proximate to respective surface portions based on the preselected spatial distribution of surface structural features on the first and second objects to form a two-object composite structure.
Abstract:
A method of identifying the energy range of radiation includes a system having a detector with energy differentiation characteristics, an electronic amplifier of a dual energy window, a data acquisition card, a digital threshold controller, a database, and a radiation energy range display. The system calculates the energy range of radiation through logical comparison, condition correction and mathematical fitting.
Abstract:
A data processing device for processing a reference background spectrum and a measurement spectrum of a radioactive material represented by a multichannel spectrum to acquire energy region information of detected gamma rays is provided, said data processing device comprising: energy region dividing means for degenerating said multichannel spectrum into a degenerated spectrum of limited channels, each degenerated spectrum representing an energy region; degenerated spectrum calculating means for calculating a background degenerated spectrum and measurement degenerated spectrum based on said background spectrum and said measurement spectrum corresponding to said degenerated spectrum of limited channels respectively; energy ratio calculating means for calculating a energy ratio based on the calculated background degenerated spectrum and measurement degenerated spectrum; peak-detection means, for searching a peak value in the calculated energy ratios; energy region determining means for determining a corresponding energy region of said gamma rays based on the searched peak value in the energy ratios. A corresponding radiation detection method and a radiation detection system employing the data processing device are also provided.
Abstract:
A white LED lighting device driven by a pulse current is provided, which consists of blue, violet or ultraviolet LED chips, blue afterglow luminescence materials A and yellow luminescence materials B. Wherein the weight ratio of the blue afterglow luminescence materials A to the yellow luminescence materials B is 10-70 wt %:30-90 wt %. The white LED lighting device drives the LED chips with a pulse current having a frequency of not less than 50 Hz. Because of using the afterglow luminescence materials, the light can be sustained when an excitation light source disappears, thereby eliminating the influence of LED light output fluctuation caused by current variation on the illumination. At the same time, the pulse current can keep the LED chips being at an intermittent work state, so as to overcome the problem of chip heating.
Abstract:
The present invention relates to a waterproof multiple rare-earth co-activated long-afterglow luminescent material having its general chemical composition depicted by a formula aMO.bAl2O3.cSiO2.dGa2O3:xEu.yB.zN, wherein a, b, c, d, x, y, and z are coefficients with the ranges of 0.5≦a≦2, 0.5≦b≦3, 0.001≦c≦1, 0.0001≦d≦1, 0.0001≦x≦1, 0.0001≦y≦1, 0.0001≦z≦1, M is Ca or Sr, N is Dy or Nd, wherein Sr (or Ca), Al, Si, Ga are main substrate matrix elements and Eu, B, Dy (or Nd) elements are activators. The waterproof multiple rare-earth co-activated long-afterglow luminescent material according to the present invention not only has advantage of a longer afterglow time, but also has water resistance greatly superior to rare-earth activated aluminate long-afterglow luminescent material in the prior art, and still keeps higher long-afterglow property after dipping into water for 60 hours, especially shows its superiority when working or used under the environment of dipping into water or dampness.