To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NC...To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NCP）,a 4-yr field experiment of growing degree-days （GDD） before winter （realized through different sowing dates） with three wheat （Triticum aestivum L.） cultivars of each type of semi-winterness and weak springness was carried out at 20 test experimental sites （32°4’N36°1’N） of Henan Province in the NCP.The results showed that：（i） yield of semi-winterness wheat was significantly higher than weak springness wheat （P〈0.01）;（ii） there was a quadratic regression between the yield and GDD before winter.According to the regression equation,the optimum GDD range with high yield of semi-winterness and weak springness wheats was 750-770 and 570-590°C d,respectively;（iii） under the optimum GDD condition,the foliar age on the main stem of semi-winterness and weak springness wheats was 7.67-7.91 and 6.36-6.86 leaves,respectively,calculated by the linear regression equation between foliar age and GDD before winter;（iv） both semi-winterness and weak springness wheats were in the double ridge stage of spike differentiation under the condition of the optimum GDD range,and at this time,the foliar age on the main stem of semi-winterness and weak springness wheats was about 7.80 and 6.07 leaves,respectively,which was consistent with the results calculated by the liner regression equation.Therefore,we could consider that the sowing date is appropriate if the foliar age is about 7.8 and 6.3 leaves for semi-winterness and weak springness wheats,respectively.According to the results of this study,choosing semi-winterness wheat and planting 710 d earlier would improve yield and natural resource utilization in NCP.展开更多
In this paper,we investigate a generalization of graph decomposition,called hypergraph decomposition.We show that a decomposition of a 3-uniform hypergraph K_v^(3)into a special kind of hypergraph K_4^(3)-e exists if ...In this paper,we investigate a generalization of graph decomposition,called hypergraph decomposition.We show that a decomposition of a 3-uniform hypergraph K_v^(3)into a special kind of hypergraph K_4^(3)-e exists if and only if v≡0,1,2(mod 9)and v≥9.展开更多
The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data colle...The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs) calculation from remotely sensed data,a novel spatio-temporal algorithm for T a estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS) data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs) above 10 ℃,from reconstructed T a based on MODIS land surface temperature(LST) data.The verification results of maximum T a,minimum T a,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.展开更多
The views of local people on climate change along different ecological regions are relatively unexplored in Nepal. This study was conducted in 13 villages in central Nepal at different altitudes to document the views ...The views of local people on climate change along different ecological regions are relatively unexplored in Nepal. This study was conducted in 13 villages in central Nepal at different altitudes to document the views of small holder farmers and compare their perception with trends of climatic variables, finger millet yield, natural disasters, plant phenology(flowering and fruiting), status of forest and wild life, as well as the spread of diseases and pests. Analysis on the climatic data of stations for 36-41 years between 1975 and 2016 showed significant increases in the minimum temperature in lower tropical climatic region(<500 m), upper tropical to subtropical climatic region(500-2000 m) and temperate climatic region(2000-3000 m) by 0.01, 0.026 and 0.054℃/year, respectively, and an increase of maximum temperature by 0.008, 0.018, and 0.019℃/year, respectively. Rainfall showed a strongly significant decreasing trend in all elevation regions. This result matches with the views of respondents except 38% respondent from temperate climatic region. People from the temperate climatic region also mentioned that current onset of snowfall is delayed but amount of snowfall remained the same. From the documented records, except events of wild fire, frequency of natural disasters events have increased in the recent years, which was in harmony with the views of local people. Multi-linear regression analysis showed that contribution of climatic variables on finger millet yield in lower tropical climatic region and upper tropical to subtropical regions was 23% and 57.3%, respectively, which was supported by increasing trend on average growing degree day(GDD) temperature at the rate of 0.01℃ in upper tropical to subtropical region and 0.007℃ in lower tropical climatic region yearly. Finger millet yield has been increasing at the rate of 7.39 and 36.9 kg/ha yearly in lower tropical climatic region and upper tropical to subtropical climatic region, respectively. This result provides deeper understanding of people's perce展开更多
Let H and J1 be both t-uniform hypergraphs. Let J2 be a sub-hypergraph of J1. In this paper, the metamorphosis of a hypergraph decomposition is introduced, denoted by (H, J1 】 J2)-design, which is a generalization of...Let H and J1 be both t-uniform hypergraphs. Let J2 be a sub-hypergraph of J1. In this paper, the metamorphosis of a hypergraph decomposition is introduced, denoted by (H, J1 】 J2)-design, which is a generalization of the concept of metamorphosis of a graph decomposition. Let Meta(J1】J2) denote the set of all integers v such that there exists a (Kv((3)), J1】J2)-design. We completely determine the set Meta(K4((3))】K4((3))-e).展开更多
The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, lo...The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.展开更多
In this paper, it is shown that the necessary conditions for the existence of a ( gv, {g, 3 α }, 3, λ)-DF in Z gv for α∈ {0, 1, 2} are also sufficient with two exceptions of (v, g, λ, α) = (9, 1, 1, 1), (9, 1, 2...In this paper, it is shown that the necessary conditions for the existence of a ( gv, {g, 3 α }, 3, λ)-DF in Z gv for α∈ {0, 1, 2} are also sufficient with two exceptions of (v, g, λ, α) = (9, 1, 1, 1), (9, 1, 2, 2). Finally, the existence spectrum of a cyclic (3, λ)-GDD of type g v is determined.展开更多
Modeling of fruit morphological formation in melon is important for realizing virtual and digital plant growth.The objective of this study was to characterize the changes in patterns of fruit growth characters during ...Modeling of fruit morphological formation in melon is important for realizing virtual and digital plant growth.The objective of this study was to characterize the changes in patterns of fruit growth characters during plant development.In cultivar experiments,a high-resolution wireless vision sensor network has been developed to realize non-contact automatic uninterrupted measurement of the fruit shape micro-change （fruit size,color,and net）.Results showed that the fruit swelling process （vertical and horizontal diameters） exhibited a slow-rapid-slow pattern,which could be well described with a logistic curve against growing degree days （GDD）;fruit color changes based on the RGB values could be represented by quadratic relationship to cumulative GDD;the fruit net changes over growth progress could be partitioned into three phases according to the time interval.The first phase was from 1 to 30 days after pollination （DAP）,in which the vertical stripe appeared at fruit middle part and the horizontal stripe at fruit petiole and hilum part as well;the second phase was from 30 to 40 DAP,the horizontal stripe occurred at fruit middle part and the net was formed;the third phase was the process started from 40 DAP,the netted breadth and thickness were gradually increased.The model was validated with the independent data from the experiment,and the mean RMSE （root mean square error） of fruit were 0.36 and 0.28 cm for vertical and horizontal diameters,11.9 for fruit color,and 0.45 cm for stripe length and diameter at varied GDD,respectively.This work is beneficial to a reliable foundation for study the relationship between morphological formation and physiological change of the melon fruit internally and then realize the intelligent precision management to improve the yield and quality of greenhouse melon production.展开更多
In statistical planning of experiments, super-simple designs are the ones providing samples with maximum intersection as small as possible. Super- simple group divisible designs are useful in constructing other types ...In statistical planning of experiments, super-simple designs are the ones providing samples with maximum intersection as small as possible. Super- simple group divisible designs are useful in constructing other types of super- simple designs which can be applied to codes and designs. In this article, the existence of a super-simple （5, 4）-GDD of group type gU is investigated and it is shown that such a design exists if and only if u ≥ 5, g（u - 2） ≥ 12, and u（u - 1）g^2≡ 0 （mod 5） with some possible exceptions.展开更多
基金supported by the Key Technologies R&D Program of China during the 11th and 12th Five-Year Plan periods(2006BAD02A07,2011BAD16B07)
文摘To provide base for adjusting the sowing date,achieving the yield potential of wheat cultivars with different growth characteristics,and improving the utilization rate of natural resource in the North China Plain （NCP）,a 4-yr field experiment of growing degree-days （GDD） before winter （realized through different sowing dates） with three wheat （Triticum aestivum L.） cultivars of each type of semi-winterness and weak springness was carried out at 20 test experimental sites （32°4’N36°1’N） of Henan Province in the NCP.The results showed that：（i） yield of semi-winterness wheat was significantly higher than weak springness wheat （P〈0.01）;（ii） there was a quadratic regression between the yield and GDD before winter.According to the regression equation,the optimum GDD range with high yield of semi-winterness and weak springness wheats was 750-770 and 570-590°C d,respectively;（iii） under the optimum GDD condition,the foliar age on the main stem of semi-winterness and weak springness wheats was 7.67-7.91 and 6.36-6.86 leaves,respectively,calculated by the linear regression equation between foliar age and GDD before winter;（iv） both semi-winterness and weak springness wheats were in the double ridge stage of spike differentiation under the condition of the optimum GDD range,and at this time,the foliar age on the main stem of semi-winterness and weak springness wheats was about 7.80 and 6.07 leaves,respectively,which was consistent with the results calculated by the liner regression equation.Therefore,we could consider that the sowing date is appropriate if the foliar age is about 7.8 and 6.3 leaves for semi-winterness and weak springness wheats,respectively.According to the results of this study,choosing semi-winterness wheat and planting 710 d earlier would improve yield and natural resource utilization in NCP.
基金This work was supported by the National Natural Science Foundation of China(Grant No.10371002)
文摘In this paper,we investigate a generalization of graph decomposition,called hypergraph decomposition.We show that a decomposition of a 3-uniform hypergraph K_v^(3)into a special kind of hypergraph K_4^(3)-e exists if and only if v≡0,1,2(mod 9)and v≥9.
基金Project supported by the National Key Technology R&D Program of China (No. 2012BAH29B02)the PhD Programs Foundation of Ministry of Education of China (No. 200100101110035)
文摘The accumulation of thermal time usually represents the local heat resources to drive crop growth.Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity.To solve the critical problems of estimating air temperature(T a) and filling in missing pixels due to cloudy and low-quality images in growing degree days(GDDs) calculation from remotely sensed data,a novel spatio-temporal algorithm for T a estimation from Terra and Aqua moderate resolution imaging spectroradiometer(MODIS) data was proposed.This is a preliminary study to calculate heat accumulation,expressed in accumulative growing degree days(AGDDs) above 10 ℃,from reconstructed T a based on MODIS land surface temperature(LST) data.The verification results of maximum T a,minimum T a,GDD,and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels.Overall,MODIS-derived AGDD was slightly underestimated with almost 10% relative error.However,the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper.Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring,agricultural climatic regionalization,and agro-meteorological disaster detection at the regional scale.
基金supported by Feed the Future Innovation Lab for Integrated Pest Management funded by the United States Agency for International Development (USAID) under the Cooperative Agreement No. AID-OAA-L-15-00001
文摘The views of local people on climate change along different ecological regions are relatively unexplored in Nepal. This study was conducted in 13 villages in central Nepal at different altitudes to document the views of small holder farmers and compare their perception with trends of climatic variables, finger millet yield, natural disasters, plant phenology(flowering and fruiting), status of forest and wild life, as well as the spread of diseases and pests. Analysis on the climatic data of stations for 36-41 years between 1975 and 2016 showed significant increases in the minimum temperature in lower tropical climatic region(<500 m), upper tropical to subtropical climatic region(500-2000 m) and temperate climatic region(2000-3000 m) by 0.01, 0.026 and 0.054℃/year, respectively, and an increase of maximum temperature by 0.008, 0.018, and 0.019℃/year, respectively. Rainfall showed a strongly significant decreasing trend in all elevation regions. This result matches with the views of respondents except 38% respondent from temperate climatic region. People from the temperate climatic region also mentioned that current onset of snowfall is delayed but amount of snowfall remained the same. From the documented records, except events of wild fire, frequency of natural disasters events have increased in the recent years, which was in harmony with the views of local people. Multi-linear regression analysis showed that contribution of climatic variables on finger millet yield in lower tropical climatic region and upper tropical to subtropical regions was 23% and 57.3%, respectively, which was supported by increasing trend on average growing degree day(GDD) temperature at the rate of 0.01℃ in upper tropical to subtropical region and 0.007℃ in lower tropical climatic region yearly. Finger millet yield has been increasing at the rate of 7.39 and 36.9 kg/ha yearly in lower tropical climatic region and upper tropical to subtropical climatic region, respectively. This result provides deeper understanding of people's perce
基金supported by National Natural Science Foundation of China (Grant Nos.10771013, 10901016) and by Prin, Pra and Indam (GNSAGA)
文摘Let H and J1 be both t-uniform hypergraphs. Let J2 be a sub-hypergraph of J1. In this paper, the metamorphosis of a hypergraph decomposition is introduced, denoted by (H, J1 】 J2)-design, which is a generalization of the concept of metamorphosis of a graph decomposition. Let Meta(J1】J2) denote the set of all integers v such that there exists a (Kv((3)), J1】J2)-design. We completely determine the set Meta(K4((3))】K4((3))-e).
文摘The main objective of this study was to evaluate the process of parameters such as mean temperature;total precipitation on phenology and phenological stages of apple golden type in Razavi Khorasan. For this reason, long-term data of absolute minimum daily temperature, precipitation, humidity, as well as Digital Elevation Model (DEM) was used. After collecting data on phenology and Growing Degree Days (GDD) for golden apple, to pass each phenological stage at different growth stages, the start and end dates, phenological stages of the locations were identified. Then, regression equations with variable longitude, latitude and altitude on SPSS software at level of 50% and 95%, respectively were used, and finally phenological stages and spatial distribution maps of temperature and precipitation variables based on these equations were drawn in ARC GIS software. The analysis of the phenological stages showed that Torbate Heydarieh station has a decreasing trend which is significant at 1% in all stages of phenology and Ghoochan station does not show any significant increase or decrease trend at all stages of phenology.
基金supported by National Natural Science Foundation of China (Grant No.10771013 and 10831002)
文摘In this paper, it is shown that the necessary conditions for the existence of a ( gv, {g, 3 α }, 3, λ)-DF in Z gv for α∈ {0, 1, 2} are also sufficient with two exceptions of (v, g, λ, α) = (9, 1, 1, 1), (9, 1, 2, 2). Finally, the existence spectrum of a cyclic (3, λ)-GDD of type g v is determined.
基金funded by the National Natural Science Foundation of China (31000669)the Shanghai Leading Academic Discipline Project,China (B209)
文摘Modeling of fruit morphological formation in melon is important for realizing virtual and digital plant growth.The objective of this study was to characterize the changes in patterns of fruit growth characters during plant development.In cultivar experiments,a high-resolution wireless vision sensor network has been developed to realize non-contact automatic uninterrupted measurement of the fruit shape micro-change （fruit size,color,and net）.Results showed that the fruit swelling process （vertical and horizontal diameters） exhibited a slow-rapid-slow pattern,which could be well described with a logistic curve against growing degree days （GDD）;fruit color changes based on the RGB values could be represented by quadratic relationship to cumulative GDD;the fruit net changes over growth progress could be partitioned into three phases according to the time interval.The first phase was from 1 to 30 days after pollination （DAP）,in which the vertical stripe appeared at fruit middle part and the horizontal stripe at fruit petiole and hilum part as well;the second phase was from 30 to 40 DAP,the horizontal stripe occurred at fruit middle part and the net was formed;the third phase was the process started from 40 DAP,the netted breadth and thickness were gradually increased.The model was validated with the independent data from the experiment,and the mean RMSE （root mean square error） of fruit were 0.36 and 0.28 cm for vertical and horizontal diameters,11.9 for fruit color,and 0.45 cm for stripe length and diameter at varied GDD,respectively.This work is beneficial to a reliable foundation for study the relationship between morphological formation and physiological change of the melon fruit internally and then realize the intelligent precision management to improve the yield and quality of greenhouse melon production.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 11371121, 11371308, 11201114, 11301457）.
文摘In statistical planning of experiments, super-simple designs are the ones providing samples with maximum intersection as small as possible. Super- simple group divisible designs are useful in constructing other types of super- simple designs which can be applied to codes and designs. In this article, the existence of a super-simple （5, 4）-GDD of group type gU is investigated and it is shown that such a design exists if and only if u ≥ 5, g（u - 2） ≥ 12, and u（u - 1）g^2≡ 0 （mod 5） with some possible exceptions.
