This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and ...This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and five simulated workplace fields with241Am-Be moderated sources).The calibration in standard fields with bare sources was conducted by following the recommendations of the ISO 8529 standard.The measured total neutron ambient dose equivalent rates,denoted as H*(10)tot,were analyzed to obtain direct components,denoted as H*(10)dir,using a reduced fitting method.The CF was then calculated as the ratio between the conventional true value of the neutron ambient dose equivalent rate in a free field,denoted as H*(10)FF,and the value of H*(10)dir.In contrast,in the simulated workplace neutron fields,the calibration of the neutron dose rate meter was conducted by following the ISO 12789 standard.The CF was calculated as the ratio between the values of H*(10)totmeasured by a standard instrument(i.e.,Bonner sphere spectrometer)and the neutron dose rate meter.The CF values were obtained in the range of 0.88–1.0.The standard uncertainties(k=1)of the CFs were determined to be in the range of approximately 6.6–13.1%.展开更多
Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that...Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that the standard metabolic rates increase with the increase of body weight at different temperatures. Relationship between them could be described as Rs = a ln W b. The mean of standard metabolic rate is significantly different among groups, but the b values are not. The standard metabolic rates of amended standard body weights decrease with the increase of temperature, and the mean of standard metabolic rate is also significantly different among groups when the standard body weights are 48.6 g, 147.9 g, and 243.1 g. Relationship between them could be described as Rsw = m e-b/T. The relations of standard metabolic rate ( Rs ) or relative metabolic rate ( Rs ) to body weight and temperature yield the following equations: Rs = 1.160 W 0.752 e -9.494/ T and Rs’= 1.160 W 0.254 e -9.494/ T.展开更多
We demonstrated a monolithic, compact, diode-pumped gain-switched Nd:YVO4 laser at 1.064 μm wavelength with controllable repetition rate of 1 Hz to 25 kHz. Stable gain-switched pulse train with maximum repetition rat...We demonstrated a monolithic, compact, diode-pumped gain-switched Nd:YVO4 laser at 1.064 μm wavelength with controllable repetition rate of 1 Hz to 25 kHz. Stable gain-switched pulse train with maximum repetition rate of 25 kHz and pulse width of 16 ns was obtained.展开更多
基金by the National Foundation for Science and Technology Development of Vietnam(No.103.04-2017.37)。
文摘This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and five simulated workplace fields with241Am-Be moderated sources).The calibration in standard fields with bare sources was conducted by following the recommendations of the ISO 8529 standard.The measured total neutron ambient dose equivalent rates,denoted as H*(10)tot,were analyzed to obtain direct components,denoted as H*(10)dir,using a reduced fitting method.The CF was then calculated as the ratio between the conventional true value of the neutron ambient dose equivalent rate in a free field,denoted as H*(10)FF,and the value of H*(10)dir.In contrast,in the simulated workplace neutron fields,the calibration of the neutron dose rate meter was conducted by following the ISO 12789 standard.The CF was calculated as the ratio between the values of H*(10)totmeasured by a standard instrument(i.e.,Bonner sphere spectrometer)and the neutron dose rate meter.The CF values were obtained in the range of 0.88–1.0.The standard uncertainties(k=1)of the CFs were determined to be in the range of approximately 6.6–13.1%.
基金This paper is financially supported by the Major Program of National Natural Science Foundation (No.497901001)Key Basic Research and Development Program(No.G1999043710)of China
文摘Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that the standard metabolic rates increase with the increase of body weight at different temperatures. Relationship between them could be described as Rs = a ln W b. The mean of standard metabolic rate is significantly different among groups, but the b values are not. The standard metabolic rates of amended standard body weights decrease with the increase of temperature, and the mean of standard metabolic rate is also significantly different among groups when the standard body weights are 48.6 g, 147.9 g, and 243.1 g. Relationship between them could be described as Rsw = m e-b/T. The relations of standard metabolic rate ( Rs ) or relative metabolic rate ( Rs ) to body weight and temperature yield the following equations: Rs = 1.160 W 0.752 e -9.494/ T and Rs’= 1.160 W 0.254 e -9.494/ T.
文摘We demonstrated a monolithic, compact, diode-pumped gain-switched Nd:YVO4 laser at 1.064 μm wavelength with controllable repetition rate of 1 Hz to 25 kHz. Stable gain-switched pulse train with maximum repetition rate of 25 kHz and pulse width of 16 ns was obtained.