No abstract available

No abstract available

[en] In gamma spectroscopy analysis, in order to improve the accuracy of the radionuclide activity, the net count of the radionuclide characteristic peaks is particularly important. The paper adopted the Gaussian function fitting the peak shape of the peak area after subtracting the background of the peak area, and the paper gets the peak shape parameters by solving the fitting equation according to the Levenberg-Marquardt method, this method takes the pretreatment resultant peak height, peak position and peak width as the initial value, and adaptive computes step size to iterate until the iteration is completed. Analyzing according to the computational simulation results, this method can fit mono-energetic peak to the best state, and the overlapped peaks can be separated into multiple single peak then do fitting. Through the experiment, the relative error between the above method measured nuclides characteristic peak area and the HPGe spectrometer measured peak area is less than 8%, the experimental results show that this method can rapidly and accurately calculate the characteristic peak area. (authors)

[en] It describes the design of a digital trapezoidal shaping filter to nuclear signals based on LabVIEW. A method of optimizing the trapezoidal shaping filter's parameters was presented and tested, and the test results of the effect of shaping filter algorithm were studied. (authors)

[en] The background of this research was the Shenzhen Universiade, and a comprehensive overview of the application of radiation monitoring instruments was given. First of all, the Shenzhen Universiade radiation monitoring program and the requirements for radiation monitoring of each venues was described; then for the Universiade radiation monitoring requirements, the appropriate radiation monitoring program was developed, and a brief introduction of the transmission and processing systems for measurement data of radiation monitoring instrumentations was offered. Finally, take the Universiade radiation monitoring equipment debugging for example, the transmission and processing of radiation monitoring data was described. (authors)

[en] 4 ∼ 5 days old male pupae of Indian meal moth, Plodia interpunctella Hubner were irradiated with 1, 3, 5, 7 and 10 krad of ⁶⁰Co γ-ray. The male moths developed from treated pupae and their F₁ generation were put together with normal female moths for copulation separately. The genetic effects of irradiation was studied and the results showed that the effects of irradiation were significant, which related to the irradiation dosage, on both parental and filial generations. Only 40% of the pupae was emerged, when they were irradiated at 10 krad. The effects on deformation rates, survival rates, copulation abilities, fecundities, hatching rates and genetic sterilities varied with different irradiation dosage treatment. With consideration of the total irradiation effect, the dosage lower than 5 krad is desirable for inducing the sterility of adults and sex chain recessive lethal gene. With 1, 5 and 7 krad of irradiation, a mutant of P. interpunctella with transparent wings was induced, which provides a marking feature in control of Indian meal moth by sex chain recessive lethal gene

[en] Radon and its daughters is a major contributor to natural background radiation dose, and it is a hot research topic now. In this paper, a simple radon measuring device of surface exhalation rate is designed, and it can be used to measure the radon exhalation rate of some sample surface. To understand the performance of the device, the radon exhalation rate of different samples are measured, and the measurement also verified the anti-radon effects of certain anti-radon coating. The measurement result shows that the radon surface exhalation rate of the sample can be given more accurate by the measuring device, but the measurement takes a long time. The device is of stable performance, easy to operate, but has some room to improve. (authors)

[en] A novel furnace throat structure was designed to reduce dust particle concentration in the flue gas emitted from the copper smelting industry. A two-stage turbulence model of the furnace throat based on the RNG k-ε model combined with the stochastic trajectory model was developed to analyze the gas flow and particle trajectories in this furnace throat structure. The resulting turbulent flow fields and particle trajectories under different operating conditions were shown and discussed. It indicates that the furnace throat plays an important role in separating the dust particles from the flue gas by applying centrifugal force and subsequent resistance force. Moreover, the effects of the radius of the inner flue, the number of the spiral plate, and the number of the spiral plate turns on the particle collection efficiency were analyzed to optimize the throat structure. The simulation results show that the furnace throat with inner flue radius of 0.05 m, two spiral plates, and two spiral plate turns has the highest particle collection efficiency. Furthermore, a series of experimental tests were conducted to validate the accuracy of the simulation results, and the measured experimental data show a good correlation with the numerical results.

[en] According to the particularity of nuclear physics experiments, In the workbench of Windows and LabVIEW, a virtual Simulation System of NIM nuclear instrument was designed and developed. And a simulation test was carried on the system. The test result showed that the system has basically realized the general function of the NIM nuclear instrument. It provided a good practice to realize and research for a new generation of NIM nuclear instruments system. (authors)

[en] Objective: To analyse the changes in bilateral optic radiation and visual cortex in patients with primary glaucoma detected by magnetization transfer imaging (MTI), and try to explore the influence of the disease on posterior visual pathway. Methods: MTI was performed in 20 patients with primary glaucoma with normal signal on conventional magnetic resonance imaging (MRI). The same scanning was performed in 31 matched healthy controls. MTI was obtained using spoiled gradient recalled acquisition sequence (SPGR). Magnetization transfer ratio (MTR) of bilateral optic radiation and visual cortex was measured after post-processing. The MTR value differences of the same area between two groups were compared by independent-sample t test or Satterthwaite t test if variances were not equality. Result: The MTR value in the left and right optic radiation were (32.8 ± 2.2)% and (32.7 ± 2.0)% in the glaucoma group, (34.6 ± 1.4 )% and (34.8 ± 1.3)% in the control group. There was a statistically significant difference between the two groups (left t=3.284, right t=4.040; P<0.01). The MTR value of the left and right visual cortex were (30.1± 2.0)% and (30.8 ± 1.8)% in the glaucoma group, and (32.3 ± 1.2 )% and (32.4 ± 1.2)% in the control group. Statistically significant difference was found between the two groups (left t=4.319, right t=3.445; P<0.01). Conclusions: Potential neuropathology changes occurring in the posterior visual pathway of patients with glaucoma indicate that the whole visual pathway may be involved by glaucoma.The micro physiological changes can be detected by MTI which can not be found by conventional MRI. It is a useful method of studying trans-synaptic damage of visual pathway n vivo glaucoma which provides more information for guiding the clinic diagnosis, cure and prognosis of glaucoma. (authors)