Three winter wheat cultivars ( Triticum aestivum L.), representatives of those widely cultivated in Beijing over the past six decades, were grown in the same environmental condition, and their physiological features w...Three winter wheat cultivars ( Triticum aestivum L.), representatives of those widely cultivated in Beijing over the past six decades, were grown in the same environmental condition, and their physiological features were investigated. Daily changes of net photosynthetic rate (P-n), transpiration (T-r) in different growth stages were measured in order to find the relationship between leaf photosynthesis and yield. Instantaneous water use efficiency (WUE) of leaf was calculated from P-n/T-r. It is suggested that relationship between photosynthetic rate and yield changed with the developing stages of wheat. High yield wheat cultivar Jingdong 8 (released in the 1990s) had a higher photosynthetic rate ( the maximal P-n increased by 77%) and transpiration rate (the maximal T-r increased by 69%), but a lower WUE than the low yield cultivar Yanda 1817 (released in the 1940s) during the day time at stem elongation stage. However; difference of P-n among the three cultivars changed with wheat growth process. Before 10 o'clock P-n in leaves of Jingdong 8 usually was the highest of the three cultivars, but P-n of Yanda 1817 was the highest after 10 o'clock. At dough ripe stage, P-n in leaves of Yanda. 1817 was the highest among the three cultivars during the whole day. The difference of changing trend of transpiration in three wheat cultivars was similar to P,, but WUE of Yanda 1817 was the highest in those three cultivars, indicating that the higher yield of Jingdong 8 was achieved via a greater consumption of water. Contrary to the cultivars released in the later period, midday depression of photosynthesis was small in Yanda 1817, which might suggest that Yanda 1817 was resistant to photoinhibition. It is possible that photosynthetic potential in leaves of wheat increased as wheat cultivars was improved over the past six decades. However, it became less resistant to photoinhibition.展开更多
There is a CAD （computer-aided design） data exchange format named SXF （scadec exchange format） in the field of Japanese public works which was developed by a consortium in 1999 to be based on the ISO 10303-202, so...There is a CAD （computer-aided design） data exchange format named SXF （scadec exchange format） in the field of Japanese public works which was developed by a consortium in 1999 to be based on the ISO 10303-202, so that the MLIT （Ministry of Land, Infi＇astructure, Transportation and Tourism） could start e-delivery （e-submit） of CAD drawings. It is one of targets for CALS/EC （continuous acquisition and lifecycle support/electric commerce） program which MLIT are promoting since 1999. Most of local governments have followed the MLIT to start e-delivery, so that SXF has become to be a standard in the public works in Japan with many problems. SXF is an exchange format and so many design companies or contractors would submit the CAD drawings with transferred format before the delivery of e-submit even if they use usually another CAD in their offices. This paper will introduce the standard of CAD exchange format SXF through the activities of Japanese public works.展开更多
This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were ...This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were within the Ikorigho and Otumara communities that recently experienced oil spillage and they are about 300 m from each other. While the third farm was within the Igbokoda community which is geographically similar but has not experienced oil spillage, it was used as control. The farmland was delineated at each area by the grid technique and soil samples were collected at 0-20 cm depth of the ground. Some physiochemical properties that reflect soil nutrient content and fertility status （pH, electrical conductivity, moisture content, organic matter, nitrogen, phosphorous and cation exchange capacity （CEC）） were determined using standard methods and results from the three areas were compared. There was a significant decrease in the calcium （Ca）, magnesium （Mg）, potassium （K） and organic matter, as well as a significant increase in the electrical conductivity, moisture content and phosphorous content of the oil-spill affected farmlands at Ikorigho and Otumara when compared with the non-affected farmland at Igbokoda. The acidic nature of the farmlands could not be attributed entirely to the oil spill since the control farmland at Igbokoda was slightly acidic. The results show that oil spillage has adversely affected the nutrient level and fertility status of farmland at Ikorigho and Otumara communities, which needs urgent remediation.展开更多
文摘Three winter wheat cultivars ( Triticum aestivum L.), representatives of those widely cultivated in Beijing over the past six decades, were grown in the same environmental condition, and their physiological features were investigated. Daily changes of net photosynthetic rate (P-n), transpiration (T-r) in different growth stages were measured in order to find the relationship between leaf photosynthesis and yield. Instantaneous water use efficiency (WUE) of leaf was calculated from P-n/T-r. It is suggested that relationship between photosynthetic rate and yield changed with the developing stages of wheat. High yield wheat cultivar Jingdong 8 (released in the 1990s) had a higher photosynthetic rate ( the maximal P-n increased by 77%) and transpiration rate (the maximal T-r increased by 69%), but a lower WUE than the low yield cultivar Yanda 1817 (released in the 1940s) during the day time at stem elongation stage. However; difference of P-n among the three cultivars changed with wheat growth process. Before 10 o'clock P-n in leaves of Jingdong 8 usually was the highest of the three cultivars, but P-n of Yanda 1817 was the highest after 10 o'clock. At dough ripe stage, P-n in leaves of Yanda. 1817 was the highest among the three cultivars during the whole day. The difference of changing trend of transpiration in three wheat cultivars was similar to P,, but WUE of Yanda 1817 was the highest in those three cultivars, indicating that the higher yield of Jingdong 8 was achieved via a greater consumption of water. Contrary to the cultivars released in the later period, midday depression of photosynthesis was small in Yanda 1817, which might suggest that Yanda 1817 was resistant to photoinhibition. It is possible that photosynthetic potential in leaves of wheat increased as wheat cultivars was improved over the past six decades. However, it became less resistant to photoinhibition.
文摘There is a CAD （computer-aided design） data exchange format named SXF （scadec exchange format） in the field of Japanese public works which was developed by a consortium in 1999 to be based on the ISO 10303-202, so that the MLIT （Ministry of Land, Infi＇astructure, Transportation and Tourism） could start e-delivery （e-submit） of CAD drawings. It is one of targets for CALS/EC （continuous acquisition and lifecycle support/electric commerce） program which MLIT are promoting since 1999. Most of local governments have followed the MLIT to start e-delivery, so that SXF has become to be a standard in the public works in Japan with many problems. SXF is an exchange format and so many design companies or contractors would submit the CAD drawings with transferred format before the delivery of e-submit even if they use usually another CAD in their offices. This paper will introduce the standard of CAD exchange format SXF through the activities of Japanese public works.
文摘This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were within the Ikorigho and Otumara communities that recently experienced oil spillage and they are about 300 m from each other. While the third farm was within the Igbokoda community which is geographically similar but has not experienced oil spillage, it was used as control. The farmland was delineated at each area by the grid technique and soil samples were collected at 0-20 cm depth of the ground. Some physiochemical properties that reflect soil nutrient content and fertility status （pH, electrical conductivity, moisture content, organic matter, nitrogen, phosphorous and cation exchange capacity （CEC）） were determined using standard methods and results from the three areas were compared. There was a significant decrease in the calcium （Ca）, magnesium （Mg）, potassium （K） and organic matter, as well as a significant increase in the electrical conductivity, moisture content and phosphorous content of the oil-spill affected farmlands at Ikorigho and Otumara when compared with the non-affected farmland at Igbokoda. The acidic nature of the farmlands could not be attributed entirely to the oil spill since the control farmland at Igbokoda was slightly acidic. The results show that oil spillage has adversely affected the nutrient level and fertility status of farmland at Ikorigho and Otumara communities, which needs urgent remediation.
