[Objective] The aim was to carry out the genetic analysis on plant height of rice（Oryza sativa L.）cultivated in different seasons.[Method] Three rice parents with great difference in plant height including CB1（83.1...[Objective] The aim was to carry out the genetic analysis on plant height of rice（Oryza sativa L.）cultivated in different seasons.[Method] Three rice parents with great difference in plant height including CB1（83.1 cm）,CB4（105.5 cm）and CB7（115.6 cm）were chosen to construct two parental combinations：CB1×CB4 and CB7×CB4,and the corresponding filial generations P1,F1,P2,B1,B2 and F2 were obtained.The 6 populations were planted in middle and late seasons respectively to measure their height traits.The Akaike＇s information criterion（AIC）of the mixed major gene and polygene model was used to indentify the existence of major genes affecting quantitative traits in B1,B2,F2 populations.When the major genes existed,the genetic effects of the major genes and polygenes and their genetic variance were estimated through segregation analysis.[Result] One additive major gene plus additive-dominance polygenes was the most fitted genetic model for the trait in all B1,B2,F2 populations in two planting seasons.The heritability values of the major genes varied from 38.63% to 78.53% and those of polygenes varied from 1.72% to 36.04%,and the total heritability values were 45.52-92.93%.The additive effect d value of the two genetic populations under two planting seasons was-4.56,-9.16,-7.19,and-9.38,respectively,as suggested that additive effect of the major genes would decrease the express of the plant height trait.[Conclusion] The heritability of plant height trait was affected by planting seasons and the combinations clearly as a whole.展开更多
Long-term variations in a sea surface wind speed （WS） and a significant wave height （SWH） are associated with the global climate change, the prevention and mitigation of natural disasters, and an ocean resource ex...Long-term variations in a sea surface wind speed （WS） and a significant wave height （SWH） are associated with the global climate change, the prevention and mitigation of natural disasters, and an ocean resource exploitation, and other activities. The seasonal characteristics of the long-term trends in China＇s seas WS and SWH are determined based on 24 a （1988-2011） cross-calibrated, multi-platform （CCMP） wind data and 24 a hindcast wave data obtained with the WAVEWATCH-III （WW3） wave model forced by CCMP wind data. The results show the following. （1） For the past 24 a, the China＇s WS and SWH exhibit a significant increasing trend as a whole, of 3.38 cm/（s.a） in the WS, 1.3 cm/a in the SWH. （2） As a whole, the increasing trend of the China＇s seas WS and SWH is strongest in March-April-May （MAM） and December-January-February （DJF）, followed by June-July-August （JJA）, and smallest in September-October-November （SON）. （3） The areal extent of significant increases in the WS was largest in MAM, while the area decreased in JJA and DJF; the smallest area was apparent in SON. In contrast to the WS, almost all of China＇s seas exhibited a significant increase in SWH in MAM and DJF; the range was slightly smaller in JJA and SON. The WS and SWH in the Bohai Sea, the Yellow Sea, East China Sea, the Tsushima Strait, the Taiwan Strait, the northern South China Sea, the Beibu Gull and the Gulf of Thailand exhibited a significant increase in all seasons. （4） The variations in China＇s seas SWH and WS depended on the season. The areas with a strong increase usually appeared in DJF.展开更多
This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40...This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.展开更多
Islands and the mainland are separated by seas,and the distances between them might be so long that the height on the mainland cannot be exactly translated to the islands,resulting in different height systems on the m...Islands and the mainland are separated by seas,and the distances between them might be so long that the height on the mainland cannot be exactly translated to the islands,resulting in different height systems on the mainland and the islands.In this study,we used astrogeodetic deflections of the vertical and ellipsoidal heights of points on the mainland and island near their coastlines to implement height connection across sea areas.First,the modeled gravity and modeled astrogeodetic vertical deflections of segmentation points along connecting routes over the sea between the mainland and the island were determined by Earth Gravity Model(EGM),and the ellipsoidal heights of segmentation points were determined by the satellite altimetry data sets.Second,we used a linear interpolation model to increase the precision of the vertical deflections of segmentation points.Third,we computed the geopotential difference of points between the mainland and the island using a method derived from geopotential theory and the astronomical leveling principle.Finally,we estimated the normal height of the point on the island using the geopotential-difference iterative computation approach.Using observed data of normal heights,ellipsoidal heights,and astrogeodetic vertical deflections referring to height sites in Qingdao,Shandong Province,we conducted a numerical experiment involving the normal height connection across sea regions.We determined the data of the ellipsoidal heights and gravity of segmentation points along the connecting route across the water in the numerical experiment using DTU10.The distance of the height connection across the sea was approximately 10.5 km.According to China's official leveling specifications,the experimental results met the criterion of third-class leveling precision.展开更多
在GNSS边坡监测中,基准站与监测站间的大高差会增加相对对流层延迟误差,严重制约实时动态差分(real time kinematic,RTK)垂向定位精度.为此,本文构建了一种顾及大高差改进的区域对流层模型.该模型基于基准站与监测站高精度天顶对流层延...在GNSS边坡监测中,基准站与监测站间的大高差会增加相对对流层延迟误差,严重制约实时动态差分(real time kinematic,RTK)垂向定位精度.为此,本文构建了一种顾及大高差改进的区域对流层模型.该模型基于基准站与监测站高精度天顶对流层延迟(zenith tropospheric delay,ZTD)模型数据,采用三次多项式函数建立ZTD与站间高程之间的函数关系,同时考虑了ZTD的季节变化特征,建立了区域对流层模型.为验证模型的有效性,以滨海某大高差边坡为研究对象,实验结果表明,本文提出的该模型有效提升了U方向的定位精度,较Saastamoinen模型、第三代全球气压和气温(Global Pressure and Temperature 3,GPT3)模型分别提升了约15%、8%.该模型有效提升站间大高差对流层误差改正效果,为GNSS大高差边坡监测提供了方案.展开更多
Driving safety is of utmost importance in the automobile industry and is acknowledged by the introduction of the tire wet grip index as part of the EU tire label. The rubber pavement interaction is determined by the v...Driving safety is of utmost importance in the automobile industry and is acknowledged by the introduction of the tire wet grip index as part of the EU tire label. The rubber pavement interaction is determined by the viscoelastic properties of the rubber as well as by the pavement texture. Nowadays available optical surface profiling instruments allow for a detailed measurement of surface roughness covering several length scales. This enables the validation of a mathematical statistical description of pavement texture within the framework of self-affine surfaces and hence provides a holistic characterization of surface roughness covering several length scales within a few characteristic parameters. We deduce within this article the correlation between classical surface roughness pa- rameters and the parameter set of self-affine surfaces. These parameters allow for a detailed understanding of the relationship between pavement texture and its wet skid resistance. We present wet skid resistance measurements with the British pendulum and a linear friction tester device on different pavement textures. We demonstrate that the so- called estimated texture depth does not correlate to the surface skid resistance measured with the British pendulum. Finally, we deduce a dependency of wet skid resistance on pavement texture which is supported by current models for hysteresis friction.展开更多
Establishing reliable elevation differences is imperative for most geoscience and engineering applications.This work has traditionally been accomplished through spirit leveling techniques;however,surveyors have been u...Establishing reliable elevation differences is imperative for most geoscience and engineering applications.This work has traditionally been accomplished through spirit leveling techniques;however,surveyors have been utilizing satellite positioning systems in measuring height differences for more than a decade.Yet the quality of these heights needs to be evaluated in order to adopt them in different applications.In this article,we present the outcome of an accuracy assessment of height differences obtained with static and RTK surveys.Twenty control points with an average baseline length of 1 km were occupied with dual-frequency GNSS receivers for different time periods.Collected signals were processed using open-source software and verified with an online processing tool.Heights were estimated by processing the GPS and the GLONASS data individually,and combined(i.e.GNSS).Height differences were determined and compared with those measured by spirit levels and corrected through geoid models.Best results were achieved by combining GPS and GLONASS solutions for both static and RTK surveys.Solutions with either GPS or GLONASS satellites were comparable,but in most cases,the GPS solutions performed better.For the static surveys,longer occupation provided much accurate height differences.Inconsistencies among 10 different RTK surveys were minimum for the GPS+GLONASS solutions and worst for the GLONASS solutions.The ANOVA,LSD,F,and χ^(2) statistical tests confirmed our findings at the 95%confidence level.展开更多
基金Supported by the Science and Technology Project of Food Production in Jiangxi Province(2006BAD02A04)~~
文摘[Objective] The aim was to carry out the genetic analysis on plant height of rice（Oryza sativa L.）cultivated in different seasons.[Method] Three rice parents with great difference in plant height including CB1（83.1 cm）,CB4（105.5 cm）and CB7（115.6 cm）were chosen to construct two parental combinations：CB1×CB4 and CB7×CB4,and the corresponding filial generations P1,F1,P2,B1,B2 and F2 were obtained.The 6 populations were planted in middle and late seasons respectively to measure their height traits.The Akaike＇s information criterion（AIC）of the mixed major gene and polygene model was used to indentify the existence of major genes affecting quantitative traits in B1,B2,F2 populations.When the major genes existed,the genetic effects of the major genes and polygenes and their genetic variance were estimated through segregation analysis.[Result] One additive major gene plus additive-dominance polygenes was the most fitted genetic model for the trait in all B1,B2,F2 populations in two planting seasons.The heritability values of the major genes varied from 38.63% to 78.53% and those of polygenes varied from 1.72% to 36.04%,and the total heritability values were 45.52-92.93%.The additive effect d value of the two genetic populations under two planting seasons was-4.56,-9.16,-7.19,and-9.38,respectively,as suggested that additive effect of the major genes would decrease the express of the plant height trait.[Conclusion] The heritability of plant height trait was affected by planting seasons and the combinations clearly as a whole.
基金The National Basic Research Program of China under contract Nos 2015CB453200,2013CB956200,2012CB957803 and2010CB950400the National Natural Science Foundation of China under contract Nos 41275086 and 41475070
文摘Long-term variations in a sea surface wind speed （WS） and a significant wave height （SWH） are associated with the global climate change, the prevention and mitigation of natural disasters, and an ocean resource exploitation, and other activities. The seasonal characteristics of the long-term trends in China＇s seas WS and SWH are determined based on 24 a （1988-2011） cross-calibrated, multi-platform （CCMP） wind data and 24 a hindcast wave data obtained with the WAVEWATCH-III （WW3） wave model forced by CCMP wind data. The results show the following. （1） For the past 24 a, the China＇s WS and SWH exhibit a significant increasing trend as a whole, of 3.38 cm/（s.a） in the WS, 1.3 cm/a in the SWH. （2） As a whole, the increasing trend of the China＇s seas WS and SWH is strongest in March-April-May （MAM） and December-January-February （DJF）, followed by June-July-August （JJA）, and smallest in September-October-November （SON）. （3） The areal extent of significant increases in the WS was largest in MAM, while the area decreased in JJA and DJF; the smallest area was apparent in SON. In contrast to the WS, almost all of China＇s seas exhibited a significant increase in SWH in MAM and DJF; the range was slightly smaller in JJA and SON. The WS and SWH in the Bohai Sea, the Yellow Sea, East China Sea, the Tsushima Strait, the Taiwan Strait, the northern South China Sea, the Beibu Gull and the Gulf of Thailand exhibited a significant increase in all seasons. （4） The variations in China＇s seas SWH and WS depended on the season. The areas with a strong increase usually appeared in DJF.
基金supported by the National Ky Basic Research Development Program(Grant Nos.2015CB453200,2013CB956200,2012CB957803,2010CB950400)the National Natural Science Foundation of China(Grant Nos.41430426,41490642,41275086,41475070)
文摘This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.
基金financially supported by the foundation of the Key Laboratory of Marine Environmental Survey Technology and Application,Ministry of Natural Resources,China (No. MESTA-2020-B006)the National Natural Science Foundation of China (No.41774001)
文摘Islands and the mainland are separated by seas,and the distances between them might be so long that the height on the mainland cannot be exactly translated to the islands,resulting in different height systems on the mainland and the islands.In this study,we used astrogeodetic deflections of the vertical and ellipsoidal heights of points on the mainland and island near their coastlines to implement height connection across sea areas.First,the modeled gravity and modeled astrogeodetic vertical deflections of segmentation points along connecting routes over the sea between the mainland and the island were determined by Earth Gravity Model(EGM),and the ellipsoidal heights of segmentation points were determined by the satellite altimetry data sets.Second,we used a linear interpolation model to increase the precision of the vertical deflections of segmentation points.Third,we computed the geopotential difference of points between the mainland and the island using a method derived from geopotential theory and the astronomical leveling principle.Finally,we estimated the normal height of the point on the island using the geopotential-difference iterative computation approach.Using observed data of normal heights,ellipsoidal heights,and astrogeodetic vertical deflections referring to height sites in Qingdao,Shandong Province,we conducted a numerical experiment involving the normal height connection across sea regions.We determined the data of the ellipsoidal heights and gravity of segmentation points along the connecting route across the water in the numerical experiment using DTU10.The distance of the height connection across the sea was approximately 10.5 km.According to China's official leveling specifications,the experimental results met the criterion of third-class leveling precision.
文摘在GNSS边坡监测中,基准站与监测站间的大高差会增加相对对流层延迟误差,严重制约实时动态差分(real time kinematic,RTK)垂向定位精度.为此,本文构建了一种顾及大高差改进的区域对流层模型.该模型基于基准站与监测站高精度天顶对流层延迟(zenith tropospheric delay,ZTD)模型数据,采用三次多项式函数建立ZTD与站间高程之间的函数关系,同时考虑了ZTD的季节变化特征,建立了区域对流层模型.为验证模型的有效性,以滨海某大高差边坡为研究对象,实验结果表明,本文提出的该模型有效提升了U方向的定位精度,较Saastamoinen模型、第三代全球气压和气温(Global Pressure and Temperature 3,GPT3)模型分别提升了约15%、8%.该模型有效提升站间大高差对流层误差改正效果,为GNSS大高差边坡监测提供了方案.
文摘Driving safety is of utmost importance in the automobile industry and is acknowledged by the introduction of the tire wet grip index as part of the EU tire label. The rubber pavement interaction is determined by the viscoelastic properties of the rubber as well as by the pavement texture. Nowadays available optical surface profiling instruments allow for a detailed measurement of surface roughness covering several length scales. This enables the validation of a mathematical statistical description of pavement texture within the framework of self-affine surfaces and hence provides a holistic characterization of surface roughness covering several length scales within a few characteristic parameters. We deduce within this article the correlation between classical surface roughness pa- rameters and the parameter set of self-affine surfaces. These parameters allow for a detailed understanding of the relationship between pavement texture and its wet skid resistance. We present wet skid resistance measurements with the British pendulum and a linear friction tester device on different pavement textures. We demonstrate that the so- called estimated texture depth does not correlate to the surface skid resistance measured with the British pendulum. Finally, we deduce a dependency of wet skid resistance on pavement texture which is supported by current models for hysteresis friction.
文摘Establishing reliable elevation differences is imperative for most geoscience and engineering applications.This work has traditionally been accomplished through spirit leveling techniques;however,surveyors have been utilizing satellite positioning systems in measuring height differences for more than a decade.Yet the quality of these heights needs to be evaluated in order to adopt them in different applications.In this article,we present the outcome of an accuracy assessment of height differences obtained with static and RTK surveys.Twenty control points with an average baseline length of 1 km were occupied with dual-frequency GNSS receivers for different time periods.Collected signals were processed using open-source software and verified with an online processing tool.Heights were estimated by processing the GPS and the GLONASS data individually,and combined(i.e.GNSS).Height differences were determined and compared with those measured by spirit levels and corrected through geoid models.Best results were achieved by combining GPS and GLONASS solutions for both static and RTK surveys.Solutions with either GPS or GLONASS satellites were comparable,but in most cases,the GPS solutions performed better.For the static surveys,longer occupation provided much accurate height differences.Inconsistencies among 10 different RTK surveys were minimum for the GPS+GLONASS solutions and worst for the GLONASS solutions.The ANOVA,LSD,F,and χ^(2) statistical tests confirmed our findings at the 95%confidence level.
