Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are an...Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.展开更多
Soil background contents of a number of elements of different soil groups, sub-groups and genus on Liaohe River Plain were investigated. It appeared that: the background levels for most elements studied were around th...Soil background contents of a number of elements of different soil groups, sub-groups and genus on Liaohe River Plain were investigated. It appeared that: the background levels for most elements studied were around the lower limits of the world's averages, variation coefficients of the background content values were from 0.3-0.5 and the element migration coefficients were between 0.9 and 1.0. It was found that the element background contents in soils of eastern and southern parts of the area were generally higher than that of western and northern parts.展开更多
The experimental data of 100 A MeV12C +12C elastic scattering are checked by using two-body kinematic calculation and12 C + p elastic scattering. It is shown that the measured data are true and reliable. In the paper,...The experimental data of 100 A MeV12C +12C elastic scattering are checked by using two-body kinematic calculation and12 C + p elastic scattering. It is shown that the measured data are true and reliable. In the paper,the transformation between the excited energy spectra of the12 C +12C system and the ground state energy spectra of the12 C + p system is introduced. The method of subtraction of the hydrogen background in the natural carbon target used in the experiment is elaborately described and the results are discussed. It is indicated that this method of subtraction of hydrogen background is reasonable and can be used in the data analysis. Based on the elastic scattering cross section of the previous experiment of12C+p at 95.3A MeV, the hydrogen content entered into the reaction is analyzed. The final hydrogen content in the natural carbon target is(2.73 ± 0.12)%.展开更多
The observed microwave background radiation （MBR） is commonly in- terpreted as the relic of an early hot universe, and its observed features （spectrum and anisotropy） are explained in terms of properties of the ea...The observed microwave background radiation （MBR） is commonly in- terpreted as the relic of an early hot universe, and its observed features （spectrum and anisotropy） are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20th century, and adapt it to modern observations. For example, the stellar Hipparcos data show that the energy density of starlight from the Milky Way, if suit- ably thermalized, yields a temperature of ~2.81 K. This and other arguments given here strongly suggest that the origin of MBR may lie, at least in a very large part, in re-radiation of thermalized galactic starlight. The strengths and weaknesses of this alternative radical explanation are discussed.展开更多
This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principl...This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested.展开更多
文摘Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.
文摘Soil background contents of a number of elements of different soil groups, sub-groups and genus on Liaohe River Plain were investigated. It appeared that: the background levels for most elements studied were around the lower limits of the world's averages, variation coefficients of the background content values were from 0.3-0.5 and the element migration coefficients were between 0.9 and 1.0. It was found that the element background contents in soils of eastern and southern parts of the area were generally higher than that of western and northern parts.
基金Supported by the Innovation Foundation of BUAA for PhD Graduates and National Natural Science Foundation of China(Nos.11035007,11235002 and 11175011)
文摘The experimental data of 100 A MeV12C +12C elastic scattering are checked by using two-body kinematic calculation and12 C + p elastic scattering. It is shown that the measured data are true and reliable. In the paper,the transformation between the excited energy spectra of the12 C +12C system and the ground state energy spectra of the12 C + p system is introduced. The method of subtraction of the hydrogen background in the natural carbon target used in the experiment is elaborately described and the results are discussed. It is indicated that this method of subtraction of hydrogen background is reasonable and can be used in the data analysis. Based on the elastic scattering cross section of the previous experiment of12C+p at 95.3A MeV, the hydrogen content entered into the reaction is analyzed. The final hydrogen content in the natural carbon target is(2.73 ± 0.12)%.
基金supported in part by the Perimeter Institute for Theoretical PhysicsResearch at the Perimeter Institute is supported by the Government of Canada through Industry Canadaby the Province of Ontario through the Ministry of Research and Innovation
文摘The observed microwave background radiation （MBR） is commonly in- terpreted as the relic of an early hot universe, and its observed features （spectrum and anisotropy） are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20th century, and adapt it to modern observations. For example, the stellar Hipparcos data show that the energy density of starlight from the Milky Way, if suit- ably thermalized, yields a temperature of ~2.81 K. This and other arguments given here strongly suggest that the origin of MBR may lie, at least in a very large part, in re-radiation of thermalized galactic starlight. The strengths and weaknesses of this alternative radical explanation are discussed.
文摘This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested.
