The Yingfengling section composed of red soil and volcanic rocks can be distinguished into 8 stratigraphic units and 4 red soil-volcanic rock cycles. 64 paleomagnetic-orientated samples were collected from the bottom ...The Yingfengling section composed of red soil and volcanic rocks can be distinguished into 8 stratigraphic units and 4 red soil-volcanic rock cycles. 64 paleomagnetic-orientated samples were collected from the bottom to the top of the section. Natural remanent magnetization and magnetic susceptibility were firstly measured. All the samples were stepwisely treated with thermal or/and alternating fields. Four clear polarity segments were recorded in the section. Compared with the geo-magnetic polarity scale, the section was formed since the late Olduvai subchron, about 1.37 Ma.B.P.展开更多
The annual frequency of red tides from 1977 to 2012 and the monthly frequency of red tides from 2001 to 2012 in China seas were used to establish the time series of red tide annual frequency and monthly frequency, res...The annual frequency of red tides from 1977 to 2012 and the monthly frequency of red tides from 2001 to 2012 in China seas were used to establish the time series of red tide annual frequency and monthly frequency, respectively. The annual frequency fit well with time segments revealed by piecewise linear regression analysis. The seasonal maximum of monthly frequency was in May （-18.22）, and the stochastic volatility tended to increase gradually with time series, with peak values occurring from May to July. Holt exponential smoothing and Holt-winter exponential smoothing were used to predict red tide annual and monthly frequencies, which revealed that the annual frequency of red tides would rise slowly by one time from 2013 to 2020, and that red tides would mainly occur from May to July in 2013-2016 with a peak value of about 25 times in May.展开更多
pH and base saturation percentage (BSP) are two basic indexes in identifying soil types in Chinese Soil Taxonomy. Some studies proved that there is significant correlation between BSP and pH, thus it could save the co...pH and base saturation percentage (BSP) are two basic indexes in identifying soil types in Chinese Soil Taxonomy. Some studies proved that there is significant correlation between BSP and pH, thus it could save the cost of laboratory work if we can infer BSP directly from pH. In this study, the measured values of BSP and pH of 162 and 232 horizon samples from 48 and 55 red soil series surveyed from 2009 to 2011 in Fujian and Guangdong respectively were adopted from Soil Series Database to set up the optimal correlation model between BSP and pH. The results showed that: 1) BSP ranged from 2.30% to 94.02% with a mean of 25.07%, while pH from 3.42 to 6.91 with a mean of 4.98 for the total soil samples. 2) There were significant differences in pH between different soil types (R2 were 0.624 for Ferralosols, 0.507 for Ferrosols, 0.515 for Argosols, and 0.456 for Cambosols, p 2 were 0.580 for Quaternary red clay, 0.434 for granite, 0.642 for sandstone, and 0.712 for basalt, p 2 were 0.623 for dryland, and 0.404 for forest land, p 0), their probability density curves were mainly in flat or normal curves (y = 6.84x2 −45.86x + 81.52, R2 = 0.494, p < 0.01).展开更多
Analyzing time series characteristics of red tide is the basis of disaster prevention and mitigation,which is very important to red tide prediction.There are trend comp onents and periodic components in annual time se...Analyzing time series characteristics of red tide is the basis of disaster prevention and mitigation,which is very important to red tide prediction.There are trend comp onents and periodic components in annual time series of occurrence freque ncy and area of red tides,so Gray-Periodic Extensional Combinatorial Model(GPECM)is used to extract these components.The fitting degree of occurrence frequency and area can reach 95.20% and 95.24%,respectively.The performance of GPECM is better than Gray Model,Fourier Series Extension Model,and Holt-Winter Exponential Smoothing Model in model stability.Consequently,it is used to forecast the occurrence frequency and area in 2020 and 2021,and results show that the annual frequency of red tides in 2020 and 2021 can rise to 39 and 41,respectively,and that the annual occurrence area of red tides can rise to 3168 km^(2),which is about 59% more than last year.In 2021,it can fall to 1901 km^(2).展开更多
文摘The Yingfengling section composed of red soil and volcanic rocks can be distinguished into 8 stratigraphic units and 4 red soil-volcanic rock cycles. 64 paleomagnetic-orientated samples were collected from the bottom to the top of the section. Natural remanent magnetization and magnetic susceptibility were firstly measured. All the samples were stepwisely treated with thermal or/and alternating fields. Four clear polarity segments were recorded in the section. Compared with the geo-magnetic polarity scale, the section was formed since the late Olduvai subchron, about 1.37 Ma.B.P.
基金financially supported by the Tianjin Marine Science and Technology Project (KJXH2011-05)local colleges and universities in Shanghai liberal arts academic programme (B5201120003)
文摘The annual frequency of red tides from 1977 to 2012 and the monthly frequency of red tides from 2001 to 2012 in China seas were used to establish the time series of red tide annual frequency and monthly frequency, respectively. The annual frequency fit well with time segments revealed by piecewise linear regression analysis. The seasonal maximum of monthly frequency was in May （-18.22）, and the stochastic volatility tended to increase gradually with time series, with peak values occurring from May to July. Holt exponential smoothing and Holt-winter exponential smoothing were used to predict red tide annual and monthly frequencies, which revealed that the annual frequency of red tides would rise slowly by one time from 2013 to 2020, and that red tides would mainly occur from May to July in 2013-2016 with a peak value of about 25 times in May.
文摘pH and base saturation percentage (BSP) are two basic indexes in identifying soil types in Chinese Soil Taxonomy. Some studies proved that there is significant correlation between BSP and pH, thus it could save the cost of laboratory work if we can infer BSP directly from pH. In this study, the measured values of BSP and pH of 162 and 232 horizon samples from 48 and 55 red soil series surveyed from 2009 to 2011 in Fujian and Guangdong respectively were adopted from Soil Series Database to set up the optimal correlation model between BSP and pH. The results showed that: 1) BSP ranged from 2.30% to 94.02% with a mean of 25.07%, while pH from 3.42 to 6.91 with a mean of 4.98 for the total soil samples. 2) There were significant differences in pH between different soil types (R2 were 0.624 for Ferralosols, 0.507 for Ferrosols, 0.515 for Argosols, and 0.456 for Cambosols, p 2 were 0.580 for Quaternary red clay, 0.434 for granite, 0.642 for sandstone, and 0.712 for basalt, p 2 were 0.623 for dryland, and 0.404 for forest land, p 0), their probability density curves were mainly in flat or normal curves (y = 6.84x2 −45.86x + 81.52, R2 = 0.494, p < 0.01).
文摘Analyzing time series characteristics of red tide is the basis of disaster prevention and mitigation,which is very important to red tide prediction.There are trend comp onents and periodic components in annual time series of occurrence freque ncy and area of red tides,so Gray-Periodic Extensional Combinatorial Model(GPECM)is used to extract these components.The fitting degree of occurrence frequency and area can reach 95.20% and 95.24%,respectively.The performance of GPECM is better than Gray Model,Fourier Series Extension Model,and Holt-Winter Exponential Smoothing Model in model stability.Consequently,it is used to forecast the occurrence frequency and area in 2020 and 2021,and results show that the annual frequency of red tides in 2020 and 2021 can rise to 39 and 41,respectively,and that the annual occurrence area of red tides can rise to 3168 km^(2),which is about 59% more than last year.In 2021,it can fall to 1901 km^(2).
