223 results about "Radiation damage" patented technology

The invention discloses an alloy high-temperature and high-pressure environment simulation method under radiation action based on molecular dynamics, which comprises the following steps: establishing a molecular structure framework of an alloy according to a crystal structure and a lattice constant of the alloy, and setting initial parameters to construct an initial simulation model; performing relaxation operation on the molecular structure model in a high-temperature and high-pressure environment; performing irradiation damage simulation on the relaxed model based on molecular dynamics, selecting a central atom as a primary off-site atom, and setting incident energy and incident direction of the primary off-site atom to simulate atom cascade collision; keeping the incident direction unchanged, and adjusting the incident energy of the primary off-site atoms to obtain defect distribution and defect density under different energies; and analyzing the defect evolution law of the alloy in the high-temperature and high-pressure environment according to the simulation result. According to the method, the alloy material is observed from a microscopic atomic scale, so that a powerful support is provided for simulating a defect evolution process in a high-temperature and high-pressure environment and reflecting atomic collision of the alloy in a real radiation environment.

The invention provides a rare earth silicon germanate scintillating material and a preparation method and application thereof, in particular to a rare earth silicon germanate scintillating material with high thermal stability and strong radiation resistance and a preparation method and application thereof, the general formula of the rare earth silicon germanate scintillating material with high thermal stability and strong radiation resistance is RE2 (1-x-delta / 2) Ce2xGedeltaSi (1-y + delta) Gey-deltaOz, in the formula, 0 lt; x is more than or equal to 0.05, y is more than or equal to 0.15 and less than or equal to 0.5, delta is more than or equal to 0 and less than or equal to 10 <-4 >, z is more than or equal to 4.95 and less than or equal to 5.05, RE represents a rare earth element, and the rare earth element is selected from at least one of lanthanum (La), lutetium (Lu), yttrium (Y) and gadolinium (Gd). The rare earth silicon germanate scintillating material provided by the invention has the characteristics of strong radiation damage resistance, high scintillation light output, low afterglow and the like while greatly improving the thermal stability, and can be used in occasions with extremely high requirements on the thermal stability or radiation resistance of the material, such as high-energy physical experiments, nuclear medicine imaging, oil exploration wells and the like.

The invention discloses a position precision compensation method for an irradiation-resistant absolute photoelectric encoder. The position precision compensation method mainly comprises a dual-sensing Kalman filtering method and a Double Deep Q-Network reinforcement learning method. The dual-sensing module of the photoelectric encoder can start the auxiliary sensor after the main sensor is damaged due to radiation damage, so that the overall radiation resistance of the encoder is improved. According to the method, position data obtained by the auxiliary sensor is used as parameters of a state estimation equation in the double-sensor Kalman filtering method and used for compensating position errors of the main sensor in radiation damage, and hyper-parameters in the Kalman filtering algorithm are optimized through the DDQN reinforcement learning method. According to the position precision compensation method for the radiation-resistant absolute photoelectric encoder, the radiation resistance of the absolute photoelectric encoder can be improved, precision reduction caused by radiation damage is compensated, and the problem of position loss occurring when a main sensor is switched to an auxiliary sensor is solved.

The invention relates to the technical field of biomedical materials, in particular to hydrogel as well as a preparation method and application thereof. The hydrogel is obtained by crosslinking a polymer framework material, a functional additive and a shielding agent, the polymer framework material comprises any one or more of gelatin, carboxymethyl chitosan, hyaluronic acid, chitosan, collagen, polyvinyl alcohol, sodium carboxymethyl cellulose and sodium alginate; the functional additive comprises any one or more of tannic acid, tea polyphenol, vitamin C and procyanidine; the shielding agent comprises any one or more of barium sulfate, bismuth simple substance and bismuth-containing compound. The hydrogel provided by the invention can effectively isolate radiotherapy rays, reduce oxidative stress reaction, provide a protective barrier for normal tissues in a radiotherapy process and reduce radiation damage, has excellent tissue repair promotion capability, is safe in components, fast in metabolism and adjustable in flowability and adhesion, and is more beneficial to adaptation in rectum or skin tissues.

The present application relates to the field of medicine, and particularly to the application of schisantherin B in the preparation of a medicine for preventing or treating radiation damage of the intestinal tract. The present application finds that schisantherin B has a protective effect on the intestinal tract after irradiation, and experiments prove that schisantherin B can reduce the pathological damage degree of the intestinal tract after irradiation, including increasing the length of intestinal villi and the number of crypts, maintaining the stability of the intestinal mucosal barrier, reducing the content of inflammatory factors in the intestinal tissue, restoring the activity of the intestinal epithelial cells after irradiation, and inhibiting the apoptosis. Meanwhile, schisantherin B can reduce the iron death caused by irradiation. Therefore, schisantherin B has a wide application prospect as a potential radiation protection agent in the treatment of radiation-induced intestinal injury and drug development.

The utility model provides an interactive experience teaching aid simulating a level gage for science popularization. The interactive experience teaching aid comprises an experiment container and a U-shaped pipe communicated with the bottom of the experiment container. The immersion liquid sensor is arranged on the side of the U-shaped pipe, and a sensing head of the immersion liquid sensor can be inserted into the U-shaped pipe; the simulated radioactive source and the simulated detector are detachably connected with the container support frame of the experimental container; the experiment container is communicated with a U-shaped pipe, so that the experiment container is flush with the liquid level of an inner cavity of the U-shaped pipe, when the amount of the injected liquid material reaches a threshold value set for science popularization demonstration teaching, an induction head of the immersion inductor makes contact with the liquid material in the inner cavity of the U-shaped pipe, and then the immersion inductor sends a signal to the simulated detector electrically connected with the immersion inductor. The buzzer and the light of the simulated detector flicker to remind an operator that injection of liquid materials is stopped when the threshold value set by teaching is reached, and the simulated radioactive source is only the same as a real radioactive source in appearance and does not have radioactivity, so that radiation damage to the operator is avoided.

The application discloses an online proton imaging ion spectrometer diagnosis system, relates to the fields of plasma physics and nuclear detection, and comprises an online proton imaging module, an online Thomson ion spectrometer module and a shielding aiming module; the shielding aiming module comprises a shielding cavity and an aiming laser pen; the online proton imaging module comprises a metal filter, a first scintillator and two proton imaging acquisition assemblies; the proton imaging acquisition assembly comprises a first optical fiber panel attached to the first scintillator and a first CMOS sensor attached to the first optical fiber panel; the online Thomson ion spectrometer module comprises an ion beam deflection mechanism and an ion spectrum diagnosis acquisition assembly; the ion spectrum diagnosis acquisition assembly comprises a light-proof aluminum film, a second scintillator, a second optical fiber panel and a second CMOS sensor which are sequentially and superposedly arranged. The application reduces the size of the whole system, can simultaneously carry out online proton imaging and ion energy spectrum diagnosis, and can effectively prevent radiation damage to the CMOS chip.

The invention discloses application of ellagic acid in preparation of a medicine or a biological product for preventing or relieving ultraviolet radiation damage and aging, and belongs to the technical field of biological medicine and radiation protection. Experimental verification shows that ellagic acid with effective concentration can promote expression of antioxidant related genes, reduce expression of inflammation response genes and expression of apoptosis related genes, eliminate active oxygen and inhibit lipid peroxidation reaction, so that oxidative damage, inflammatory reaction and apoptosis caused by ultraviolet radiation are effectively relieved, and the anti-inflammatory effect of ellagic acid is improved. The stress tolerance of an organism is improved, and the aging health risk induced by ultraviolet radiation is relieved; the medicine or biological product can be applied before and / or after exposure of ultraviolet radiation, and is suitable for preventing or relieving oxidative damage and cell aging caused by ultraviolet radiation. The invention provides a new way for developing safe and effective ultraviolet radiation protection and anti-aging preparations.

The invention relates to an evaluation method and system for a non-metallic material irradiation damage effect. The evaluation method comprises the following steps: constructing a geometric model according to material attributes of the non-metallic material, wherein the material attributes comprise chemical bonds; performing a simulation irradiation test on the geometric model by using a preset irradiation simulation environment and a preset irradiation physical model; calculating the bond breaking probability of the chemical bond according to the energy deposition information in the simulated irradiation test process; and obtaining the damage index of the non-metallic material according to the bond breaking probability. The evaluation efficiency and accuracy of the irradiation damage effect of the non-metallic material in the complex irradiation environment can be improved.

The application discloses a method, device and equipment for detecting the operation state of a ventricular assist device, and belongs to the technical field of medical instruments. The ventricular assist device comprises a driving device and an intervention pump. The driving device is used for driving the intervention pump to operate. The method comprises the following steps: acquiring current data of the driving device in a working state; in the case that the current data indicates that the load of the driving device is increased, performing operation state classification identification on the ventricular assist device according to the change condition of the current data in a first time period; and issuing alarm information corresponding to an identification result, wherein the identification result indicates an abnormal operation state causing the load increase. The method can timely prompt the cause of the abnormal load increase without the aid of a medical contrast imaging device, realizes automatic identification of the abnormal operation state, reduces the safety risk and protects the life safety of an assisted object, and reduces the radiation damage to the human body when the medical contrast imaging device is working.

The application provides a heterojunction bipolar transistor defect detection method, which comprises the following steps: acquiring a C-V curve and a 1 / C 2 -V curve of a heterojunction bipolar transistor at a preset voltage; determining the change of the C-V curve and the 1 / C 2 -V curve in a first preset voltage range; and controlling a C-V test module or an I-V test module of deep level transient spectroscopy to detect defects of the heterojunction bipolar transistor according to the change. The heterojunction bipolar transistor defect detection method has the beneficial effects that the different test modules of deep level transient spectroscopy can detect the defect types and defect states of the heterojunction bipolar transistor, and the internal defect properties and radiation damage mechanisms of the heterojunction bipolar transistor can be analyzed in depth.

The utility model relates to a medical scanning system and a water mold tool for SPECT correction of the medical scanning system. Comprising a water mold, a skeleton and a radioactive source. The framework comprises a plurality of supporting pieces, the supporting pieces are connected with one another and define a polyhedral geometric structure with a containing cavity, and the water mold is arranged in the containing cavity; the radioactive source comprises a long line source, a point source and a short line source, one of the long line source, the point source and the short line source is selected to be arranged on the framework, and the long line source is longer than the short line source; wherein the support piece comprises a first support piece, the length of the first support piece is adjustable, a fixed point is formed at the joint of any two connected support pieces, and one of the long line source, the point source and the short line source is selectively fixed on the first support piece or the fixed point. According to the water mold tool, uniformity calibration of the probe or the collimator, registration correction of the SPECT equipment and the CT equipment and posture and sensitivity correction of the probe can be achieved at the same time, time and labor are saved during calibration, and radiation damage to operators can be reduced.

The invention relates to the technical field of terminal sterilization and filtration in a radiopharmaceutical preparation process, in particular to a filter membrane sterilization and filtration device and system. Comprising the steps that a state sensing module collects liquid medicine radioactive activity data and filter membrane structure strain data and generates real-time data flow; the twinborn modeling module constructs a filter membrane digital twinborn body, and outputs an accumulated radiation damage prediction result through data assimilation; the prediction decision module generates a filtering parameter optimization sequence by using a deep reinforcement learning agent; the control execution module adjusts the flow velocity of the liquid medicine through fuzzy self-adaptive PID control and feed-forward compensation; and the verification feedback module performs an integrity test and transmits data back to the twin modeling module to realize model parameter correction. All the modules form a closed-loop control system through a high-speed data bus, so that the damage of radiation to a filter membrane material is effectively inhibited, and the integrity and the sterile guarantee level of a membrane structure in the filtering process are maintained.

The invention discloses application of ellagic acid in preparation of a medicine for preventing or treating ionizing radiation injury, and belongs to the technical field of biological medicine and radiation protection. Experiments prove that ellagic acid with an effective concentration can inhibit lipid peroxidation, enhance the activity of glutathione transferase and superoxide dismutase and promote the expression of antioxidant related genes such as sod-1, sod-2, gst-1 and gst-29 and immune related genes such as lys-1, irg-1, irg-2 and mul-1, so that the ellagic acid with an effective concentration can inhibit lipid peroxidation and improve the activity of glutathione transferase and superoxide dismutase. Therefore, oxidative damage, inflammatory response, reduced stress tolerance, accelerated aging and shortened service life caused by ionizing radiation exposure are relieved, and the compound can be applied to preparation of drugs for preventing or treating ionizing radiation damage and is suitable for nuclear accident emergency protection, space radiation protection of astronauts and adjuvant therapy of tumor radiotherapy patients. The invention provides a theoretical basis for developing an efficient and low-toxicity ionizing radiation protective agent based on ellagic acid, and has a wide application prospect.

A kind of quick bag sealing device and method for narrow space radioactive atmosphere isolation, including quick detachable inspection area, equipment back loading area, disassembly operation area;Wherein quick detachable inspection area, equipment back loading area, disassembly operation area all have sealing;And the top of quick detachable inspection area, equipment back loading area is equipped with crane hook reserved interface;Disassembly operation area side has PE operation glove, bottom has operation hole reserved interface.This application can significantly reduce the risk of radioactive material leakage by effective sealing mechanism, protect the operating personnel from radiation damage, while preventing radioactive aerosol from polluting the external environment.Using multiple sealing technology, including buckle and heat sealing, ensures zero leakage of radioactive atmosphere, meets strict radiation protection standards.Effective sealing and isolation measures reduce the possibility of radioactive material release into the environment, help maintain ecological safety.

The invention provides a strain capable of resisting radiation damage as well as a product and application thereof, and relates to the technical field of probiotics capable of resisting radiation damage. The probiotic strains are separated from healthy breast milk and comprise lactobacillus gasseri LG02, lactococcus lactis LL6 and bifidobacterium adolescentis BA18, and the three probiotic strains can improve the survival rate after ionizing radiation; the LG02 or LL6 strain relieves damage of ionizing radiation to tissue structures of the heart, the liver, the spleen, the lung, the kidney, the stomach, the small intestine, the colon and the femur, the physiological function of an organism is maintained, and recovery of the tissue structures is accelerated; the LG02 or LL6 strain accelerates the body repair after radiotherapy, reduces the side reactions of diarrhea, stomachache, constipation and cough, and reduces the incidence rate of hematochezia and radiation pneumonitis; the LG02 or LL6 strain increases or recovers the number of leukocytes, and improves the hematopoietic ability and immunity of the organism; the LG02 or LL6 strain has the effects of inhibiting harmful bacteria, improving the anti-infection and anti-inflammation capability of the body and improving the resistance; the LG02 or LL6 strain can improve the oxidation resistance of the body and enhance the aging resistance of the body.

This invention discloses a radiation effect simulation method for SRAM-type FPGAs. It combines device-level and circuit-level modeling simulation to simulate the combined effects of total dose and single-event effects on the FPGA, analyzing the impact of various radiation effects on the FPGA's operating state. This method solves the problems of limited accelerator resources, difficulty in adjusting irradiated particle energy, and high economic costs. It helps to understand the changes in internal micro-parameters of the device and reveal the damage mechanism, enabling the evaluation of the device's radiation damage sensitivity. It provides technical support for FPGA radiation resistance evaluation and hardening design, and is economical and convenient. It can be used to evaluate the radiation resistance of devices, contributing to improved device reliability in aerospace engineering applications.

This invention discloses a specialized laser welding machine for leg tube connectors, comprising a frame on which are mounted a tooling and rotating assembly, a leg tube pressing assembly, a welding torch control assembly, and an ejection mechanism. The tooling and rotating assembly includes a hollow rotating platform, a servo motor, and tooling components. The leg tube pressing assembly includes a top plate, guide columns, a cylinder, a lifting plate, and an upper positioning block. The welding torch control assembly includes a servo motor, a ball screw assembly, a welding lifting plate, and an adjustable welding torch assembly with adjustable position, angle, and posture. This invention provides a specialized laser welding machine for leg tubes and leg tube connectors, enabling automated welding between the connectors and the leg tubes. Workers are kept away from the welding point, reducing laser radiation damage to the eyes and skin. Welding fumes and gases can be removed by a vacuum cleaner. This invention positions the upper and lower ends of the leg tubes to ensure product verticality and dimensional stability. The ejection mechanism easily removes the welded product from the positioning block.

The invention provides a GEO electric propulsion satellite orbital transfer process solar cell radiation effect rapid evaluation method, which comprises the following steps that: firstly, a solar cell radiation damage space distribution database is constructed through space radiation effect analysis software, and the database comprises daily average equivalent 1MeV electron flux distribution data under different orbit heights, inclination angles and cover glass thicknesses; generating satellite space track data according to an electric propulsion orbital transfer strategy; counting accumulated operation time of the satellite in each height and dip angle interval according to a preset interval; and finally, multiplying and accumulating the daily average equivalent 1MeV electron flux corresponding to each interval by the accumulated running time to quickly obtain the accumulated equivalent 1MeV electron flux in the whole orbital transfer process. Therefore, the problem of long calculation time consumption of a traditional method is solved, and rapid evaluation support can be provided for radiation mitigation optimization design of the orbital transfer strategy.

The present invention discloses a method for preparing a sample for analyzing the interface damage behavior of Mg / Al laminated materials. The method comprises the following steps: using SRI M software to calculate the damage behavior of Mg / Al laminated materials at different energies. + The incidence depth in the Mg / Al stacked material is determined, and the depth of the irradiation damage layer of the incident ions with specific energy is calculated; according to the results of SRI M calculation, the ion beam cutting is performed on the ion irradiated sample; ion beams with different beam current sizes are sequentially selected to thin the cut interface sample; by adjusting parameters such as the electrolytic polishing liquid ratio, polishing temperature, polishing time, and polishing voltage, the optimal "rapid polishing" process parameters of the Mg / Al stacked material interface sample are explored; this method can effectively complete the preparation of Mg / Al interface transmission electron microscopy samples in Mg / Al stacked materials after ion irradiation by combining SRI M software simulation, ion beam micro-nanoscale processing, differentiated thinning process and "rapid polishing" treatment, so as to realize the analysis of Mg / Al interface radiation damage behavior and the rapid screening of high-performance Mg / Al stacked materials.

The utility model provides a kind of test equipment of radiation angle of ray source, applied to radiation imaging technical field, comprising: detector clamping device, control device and shielding device, detector clamping device is structured as can rotate within preset angle, suitable for clamping detector;Control device is connected with detector clamping device communication;Shielding device is set between detector clamping device and control device. Detector clamping device can rotate within preset angle can drive detector to any position within preset angle, whereby, detector can record the radiation dose of the radiation of to-be-measured ray source to any position within preset angle range, to calculate the radiation angle of the ray source to be tested according to radiation angle algorithm. The efficiency of the detector clamping device driving the detector to collect radiation dose is high, and the accuracy is high. The shielding device is set between the detector clamping device and the control device to shield the radiation damage of the rays to the detection personnel.

A radiation-resistant light-emitting diode lamp module is provided. The illumination light generating structure includes an illumination light generating structure (1), a top radiation-hard structure (2), a radiation-hard, light-transmitting structure (3), a bottom radiation-hard structure (4), and a surrounding radiation-hard structure (5). The top radiation-hard structure includes a top radiation-hard element (20) disposed above the illumination light generating structure. The radiation-hard, light-transmitting structure includes a first radiation-hard, light-transmitting element (31) disposed above the illumination light generating structure and a second radiation-hard, light-transmitting element (32) disposed above the first radiation-hard, light-transmitting element. The bottom radiation-hard structure includes a bottom radiation-hard element (40) disposed below the illumination light generating structure. The surrounding radiation-hard structure includes a surrounding radiation-hard element (50) disposed around the illumination light generating structure. The illumination light generating structure is completely covered by the top radiation-hard element, the first radiation-hard, light-transmitting element, the bottom radiation-hard element, and the surrounding radiation-hard element, thereby reducing radiation damage to the illumination light generating structure in a high-radiation environment.

The invention discloses a radiation refrigeration fiber membrane as well as a preparation method and application thereof. The fiber membrane comprises the following components: a polylactic acid-perfluoropolyether block copolymer, fluoroalkylated silicon dioxide and aluminum oxide in a mass ratio of 1.0: (0.05-0.50): (0.05-0.10). Fluorinated components are introduced to the surfaces of a polymer matrix and inorganic filler particles through chemical bonding, so that the radiation refrigeration performance of the composite material is improved and strengthened, the composite material is endowed with a super-hydrophobic function, the anti-pollution capacity of the material is improved, and the material can effectively bear long-term exposure in the sun and resist ultraviolet radiation damage; the scheme that the matrix and the inorganic filler are subjected to fluorination modification at the same time also overcomes the defect that the mechanical property of the composite material is insufficient due to poor compatibility of the two components; the fiber membrane is prepared through an electrostatic spinning method, the problem that a coating in a traditional coating material is prone to failure and damage is solved, and the service life of the composite material is prolonged.

The present disclosure provides a method for restoring the photoelectric parameters of a photoelectric imaging device after on-orbit operation, wherein the photoelectric imaging device is damaged by radiation from high-energy particles after on-orbit operation, comprising: S1, placing the photoelectric imaging device in a darkroom cavity whose surface is covered with a shading unit; S2, adjusting the darkroom cavity to a preset temperature using a temperature control system; the temperature control system at least includes a signal processing circuit, a thermistor, a heat dissipation element, a heating element, an analog-to-digital converter, and a multi-way analog switch; S3, annealing the photoelectric imaging device for a preset time, and recording the annealing condition information; S4, setting test parameters using a control module in a test system, and collecting image data of the photoelectric imaging device at different integration times; S5, processing the image data using a computer to obtain key parameter data, and restoring the photoelectric parameters of the photoelectric imaging device based on the annealing condition information and the key parameter data.

The invention discloses a seleno-heptamethine indocyanine compound and a preparation method and application thereof.The seleno-heptamethine indocyanine compound is of a structure shown in the formula Se-Cys, the seleno-heptamethine indocyanine compound can be specifically accumulated in cell mitochondria, excessive reactive oxygen species (ROS) generated by radiation-induced mitochondria is efficiently removed, and the compound can be used for preparing a medicine for treating the mitochondria. Therefore, the radiation damage of normal cells is reduced. Meanwhile, the compound has an ROS concentration-dependent near-infrared fluorescence enhancement effect, and can synchronously realize the effects of monitoring the ROS level in real time, avoiding excessive oxidation resistance, reducing the toxicity of anti-radiation drugs and the like.

The invention discloses a product for treating radiation damage. According to the application, GP532 is subjected to random mutation, a phage mutation library is established, and the mutation library is activated and screened by using TLR5-dependent NF-kappa B, so that 9E1 is obtained. 9E1 shows dose-dependent stimulation of TLR5 dependent NF-kB activation in vitro; an effective prevention effect is shown in an in-vivo mouse radiation injury model, and a new way is provided for effective treatment of radiation injury.

This invention relates to a method and system for treating interface contaminants in a mixing and clarification tank, belonging to the field of nuclear fuel reprocessing. The method involves conveying interface contaminants to the final stage mixing and clarification tank via top-tank operation, separating the organic phase, and then returning the liquid containing interface contaminants from the final stage mixing and clarification tank to the organic phase inlet of the first stage mixing and clarification tank. The interface contaminants are dispersed by the agitation of the pump impeller within the mixing and clarification tank, thereby redissolving radioactive materials in the liquid. This invention utilizes in-situ treatment of interface contaminants and recovery of radioactive elements in a mixing and clarification tank, significantly reducing the accumulation of radioactivity in interface contaminants, mitigating radiation damage from organic solvents, and is simple to operate without requiring additional treatment equipment.

The utility model provides a low attenuation rate reflector used for light field indication of a beam limiting device, the low attenuation rate reflector comprises a support structure and a lens, the support structure comprises an upper support member and a lower support member, the upper support member and the lower support member are detachably connected, the lens is arranged between the upper support member and the lower support member, and the lens is arranged between the upper support member and the lower support member. At least four fixing points are evenly arranged between the upper supporting piece and the lower supporting piece, the lens is fixed to the beam limiting device through a supporting structure and comprises a resin substrate and a reflecting layer arranged on the resin substrate, the resin substrate is used for reflecting visible light, and the reflecting layer is used for enhancing the reflection amount of the visible light. According to the low-attenuation-rate reflector, the imaging quality can be guaranteed, and meanwhile radiation damage to the human body can be reduced. The utility model also discloses a beam limiting device comprising the low-attenuation-rate reflector.

The application discloses a method for testing anti-radiation damage performance of calcium fluoride crystal. The method adopts X-ray radiation to irradiate calcium fluoride crystal, and judges the anti-radiation damage performance of the crystal according to an X-ray radiation dose for inducing color center absorption peak of the calcium fluoride crystal and a color center absorption coefficient of a characteristic absorption peak induced by radiation.

1. The name of the design product: CT ray protection device. 2. The use of the design product: The protection part of the CT ray protection device is installed in the CT scanning channel of the CT machine, which blocks the scattered rays generated during CT scanning from causing radiation damage to the undetected parts of the examinee and the accompanying personnel in the machine room. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.