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[Introduction] The paper aims to study the dynamic performance of the H-class gas turbine foundation, obtain the relationship between the key influencing parameters and the basic performance of the gas turbine, and guiding the parameters selection and engineering design. [Method] The foundation thickness of H-class gas turbine, concrete elastic modulus, unbanlance force and damping ratio were selected as the key influencing parameters, and the three-dimensional finite element model of H-class gas turbine foundation was established through ANSYS, and the harmonic response analysis method was used to obtain the dynamic amplitude of the foundation under the unbanlance force. [Result] Through a large number of finite element calculation and analysis, the response surface about the maximum control amplitude of the H-class gas turbine foundation，the thickness of the foundation and the elastic modulus of concrete presents an S-shaped curved surface, which has relatively flat ends and rapid growth in the middle; The amplitude of the basic control point of the gas turbine increases proportionally with the increase of the unbanlance force. While the amplitude change caused by the damping change is not monotonous, and the increase of the damping may increase or decrease its amplitude. [Conclusion] In engineering design analysis, the parameters of appropriate foundation thickness, concrete elastic modulus, unbanlance force and damping ratio should be selected based on specific engineering data and design conditions, which is the prerequisites to obtain correct and reliable dynamic performance analysis and gas turbine foundation design.

The defluoroborylation of fluoroarenes by chromium-catalyzed cleavage of unactivated C–F bonds is described. The reaction uses HBpin as the boron source, low-cost and commercially available chromium salt as the precatalyst, and terpyridine as a crucial ligand, providing a protocol with atom-efficient benefits and a wide range of applicable substrates for the functionalization of aryl C–F bonds. Preliminary mechanistic studies indicate that an unprecedented Cr-catalyzed magnesiation of the unactivated C–F bond occurred. The generated arylmagnesium intermediates then participated in the subsequent borylation reaction. The application of the strategy in the preparation of valuable derivatives is demonstrated by the late-stage functionalization of boronate ester groups. [ABSTRACT FROM AUTHOR]

A nationwide survey was conducted in 2014 to investigate environmental outdoor radon level in 33 provincial cities across China. The radon detector used was a passive-type solid-state nuclear track detector, CR-39. Measurements were conducted under the same condition following the quality control programme. Outdoor radon concentrations in China ranged from 3 to 30.0 Bq·m−3. The annual arithmetic and geometric mean radon concentration were 14 and 13.2 Bq·m−3, respectively. The radon concentrations in the locations near or along coastline were lower than the average value, while those located in the inland area were higher. As a whole, the result showed no big difference from the data measured during the period 1983–1998. It demonstrated that the outdoor radon concentration level in China has not been changing remarkably for 20 years.

For the purpose of obtaining the smaller uncertainties for H p(3) and D p lens in 90Sr/90Y beta reference fields, a new dose determination method based on the Monte-Carlo simulation was proposed. The conversion coefficients from the absorbed dose in air, at the reference point of the extrapolation ionisation chamber, D air, det to H p(3; α) and the conversion factors from D air, det to D p lens(α) were calculated with EGSnrc, respectively, for the irradiation angles from 0° to 60°. Compared with the dose determination method in International Organization for Standardization (ISO) 6980 standard, the uncertainty reductions of 7.7–52.8% for H p(3; α) and 7.9–55.0% for D p lens(α) were achieved, respectively. In addition, for the conversion coefficients from the reference absorbed dose D R to H p(3; α), the calculations were performed for more irradiation conditions, which are not included in the current ISO 6980 standard. For the calculations of the conversion factors from D R to D p lens(α), the eye and head phantoms with Chinese characteristics were utilised, which makes the conversion factors more suitable for use in China. [ABSTRACT FROM AUTHOR]

The exploitation of mineral resources may cause the environmental release of radionuclides and their introduction in the human trophic chain, affecting public health in the short and long term. A case study of the environmental radiation impact from coal mining and germanium processing was carried out in southwest China. The coal mines contain germanium and uranium and have been exploited for more than 40 years. The farmlands around the site of the coal mining and germanium processing have been contaminated by the solid waste and mine water to some extent since then. Samples of crops were collected from contaminated farmlands in the research area. The research area covers a radius of 5 km, in which there are two coal mines. 210Pb and 210Po were analyzed as the key radionuclides during the monitoring program. The average activity concentrations of 210Pb and 210Po in the crops were 1.38 and 1.32 Bq/kg in cereals, 4.07 and 2.19 Bq/kg in leafy vegetables and 1.63 and 1.32 Bq/kg in root vegetables. The annual effective doses due to the ingestion of 210Pb and 210Po in consumed crops were estimated for adult residents living in the research area. The average annual effective dose was 0.336 mSv/a, the minimum was 0.171 mSv/a and the maximum was 0.948 mSv/a. The results show that the crops grown on contaminated farmland contained an enhanced level of radioactivity concentration. The ingestion doses of local residents in the research area were significantly higher than the average level of 0.112 mSv/a in China, and the world average level of 0.042 mSv/a through 210Pb and 210Po in crop intake, respectively. [ABSTRACT FROM AUTHOR]

Here, an anatomic model of mullet is developed on sampling, dissection, and measurement on site. A Monte Carlo code is used to compute the energy-absorbed fraction in tissues and organs of the mullet, and dose rates are calculated. Some previous methods are selected for comparison. The results calculated by means of a newly developed anatomic model indicate that the dose rate to each tissue/organ is different, and dose rates to some tissues/organs are much larger than those calculated based on previous uniform models. This suggests that it is necessary to exploit an anatomic model if there are various concentration factors within the organism. Taking the organism as a whole, the anatomic model has smaller internal dose rates and middle external dose rates among these methods. [ABSTRACT FROM AUTHOR]