The relation between methylene blue （MB） value of MS and its limestone dust content and clay content was investigated. The effects of MB value ranging from 0.35 to 2.5 on the workability of fresh concrete and crack ...The relation between methylene blue （MB） value of MS and its limestone dust content and clay content was investigated. The effects of MB value ranging from 0.35 to 2.5 on the workability of fresh concrete and crack propagation characteristics at the age of 24 hours, and effects on the mechanical properties, dry shrinkage of the harden concrete were tested. The experimental results show that the MB value is not related with the limestone dust content of MS, but in direct proportion to clay content. With the increase of MB value, the concrete workability decreases, and the flexural strength and 7 d compressive strength reduce markedly, whearas the 28 d compressive strength is not affected. When the MB-value is less than or equal to 1.35, the change of the MB-value has a little influence on early plastic cracking and dry shrinkage property of concrete, but when the MB-value is more than 1.35, the tendency of plastic cracking and dry shrinkage is remarkable.展开更多
Based on the analysis on the status quo of natural resources input in Brain production and on the policy of Brain subsidies, this paper puts forward a new idea - establishing grain subsidies through assessing the valu...Based on the analysis on the status quo of natural resources input in Brain production and on the policy of Brain subsidies, this paper puts forward a new idea - establishing grain subsidies through assessing the value of the natural resources in Brain production. The assessment of the natural resources in Brain production provides rationale and reference standard for the policy of Brain subsidies, which will promote the sustainable use of natural resources accordingly. This paper concludes： （1） it is necessary for the grain subsidies to assess the full value of natural resources, including economic value, ecological value and social value： （2） the government should give farmers direct subsidies or environment subsidies according to the economic and ecological value of natural resources in grain production, （3） the social value of natural resources can be realized by establishing the country social security system, taking the social value as the criterion for the payment for part of farmers＇ insurance.展开更多
The grain quality of 100 uplandlahu rice genotypes from Assam, India was assessed. The characteristics measured were grain length, grain width, cooked grain length, cooked grain width, grain elongation ratio after coo...The grain quality of 100 uplandlahu rice genotypes from Assam, India was assessed. The characteristics measured were grain length, grain width, cooked grain length, cooked grain width, grain elongation ratio after cooking, grain widening ratio after cooking, alkali spreading value, gel consistency, as well as starch, amylose, amylopectin and total soluble sugar contents. Considerable genetic variability among the 100 rice genotypes was observed for the characteristics under study. Analysis of vadance revealed highly significant differences among the genotypes for all the characteristics. The difference between genotypic coefficient of variation （GCV） and phenotypic coefficient of variation （PCV） was very small for all the characteristics analyzed. High GCV and PCV were found in the characteristic of total soluble sugar content followed by alkali spreading value. The high values for these traits signify the scope for selection to develop superior genotypes. High heritability was recorded in all the characteristics analyzed along with diverse genetic advance which varied from 9.71% to 52.83%. The characteristic of total soluble sugar content showed high heritability with high genetic advance, whereas alkali spreading value and grain widening ratio presented high hedtability with moderate genetic advance. This implies that these characteristics are mainly under additive gene effects and could be relied upon further selection based on phenotypic performance. The genotypic correlation coefficient was higher than the phenotypic correlation coefficient, indicating strong inherent associations among the characteristics studied.展开更多
This work aims to present a perspective for porosity formation in three different alloys:A356,A413 and A380.1 by taking into account the addition of Al-B grain refiners:AlTi5B1 and Al3B.The directional solidification ...This work aims to present a perspective for porosity formation in three different alloys:A356,A413 and A380.1 by taking into account the addition of Al-B grain refiners:AlTi5B1 and Al3B.The directional solidification method was used,and microstructural changes of the alloys and its correlation with porosity formation were investigated.Pore size,number of pores,average pore length and distribution of pores were statistically analyzed.Also,external shrinkage was examined,and the volume of external shrinkage was calculated.It was found that there was a relationship between external shrinkage and the size and number of pores.As the size and number of pores internally decrease,external shrinkage increases.Additionally,porosity is decreased in all the three Al-Si alloys when Al-B grain refiners are used.The distribution of pore diameters is low when AlTi5B1 is used.Grain refiners have a different effect on porosity formation of Al-Si alloys with regard to their solidification morphology.展开更多
基金Funded by the Nationd West Communication Construction Technology Project(No.200331881106)
文摘The relation between methylene blue （MB） value of MS and its limestone dust content and clay content was investigated. The effects of MB value ranging from 0.35 to 2.5 on the workability of fresh concrete and crack propagation characteristics at the age of 24 hours, and effects on the mechanical properties, dry shrinkage of the harden concrete were tested. The experimental results show that the MB value is not related with the limestone dust content of MS, but in direct proportion to clay content. With the increase of MB value, the concrete workability decreases, and the flexural strength and 7 d compressive strength reduce markedly, whearas the 28 d compressive strength is not affected. When the MB-value is less than or equal to 1.35, the change of the MB-value has a little influence on early plastic cracking and dry shrinkage property of concrete, but when the MB-value is more than 1.35, the tendency of plastic cracking and dry shrinkage is remarkable.
文摘Based on the analysis on the status quo of natural resources input in Brain production and on the policy of Brain subsidies, this paper puts forward a new idea - establishing grain subsidies through assessing the value of the natural resources in Brain production. The assessment of the natural resources in Brain production provides rationale and reference standard for the policy of Brain subsidies, which will promote the sustainable use of natural resources accordingly. This paper concludes： （1） it is necessary for the grain subsidies to assess the full value of natural resources, including economic value, ecological value and social value： （2） the government should give farmers direct subsidies or environment subsidies according to the economic and ecological value of natural resources in grain production, （3） the social value of natural resources can be realized by establishing the country social security system, taking the social value as the criterion for the payment for part of farmers＇ insurance.
文摘The grain quality of 100 uplandlahu rice genotypes from Assam, India was assessed. The characteristics measured were grain length, grain width, cooked grain length, cooked grain width, grain elongation ratio after cooking, grain widening ratio after cooking, alkali spreading value, gel consistency, as well as starch, amylose, amylopectin and total soluble sugar contents. Considerable genetic variability among the 100 rice genotypes was observed for the characteristics under study. Analysis of vadance revealed highly significant differences among the genotypes for all the characteristics. The difference between genotypic coefficient of variation （GCV） and phenotypic coefficient of variation （PCV） was very small for all the characteristics analyzed. High GCV and PCV were found in the characteristic of total soluble sugar content followed by alkali spreading value. The high values for these traits signify the scope for selection to develop superior genotypes. High heritability was recorded in all the characteristics analyzed along with diverse genetic advance which varied from 9.71% to 52.83%. The characteristic of total soluble sugar content showed high heritability with high genetic advance, whereas alkali spreading value and grain widening ratio presented high hedtability with moderate genetic advance. This implies that these characteristics are mainly under additive gene effects and could be relied upon further selection based on phenotypic performance. The genotypic correlation coefficient was higher than the phenotypic correlation coefficient, indicating strong inherent associations among the characteristics studied.
文摘This work aims to present a perspective for porosity formation in three different alloys:A356,A413 and A380.1 by taking into account the addition of Al-B grain refiners:AlTi5B1 and Al3B.The directional solidification method was used,and microstructural changes of the alloys and its correlation with porosity formation were investigated.Pore size,number of pores,average pore length and distribution of pores were statistically analyzed.Also,external shrinkage was examined,and the volume of external shrinkage was calculated.It was found that there was a relationship between external shrinkage and the size and number of pores.As the size and number of pores internally decrease,external shrinkage increases.Additionally,porosity is decreased in all the three Al-Si alloys when Al-B grain refiners are used.The distribution of pore diameters is low when AlTi5B1 is used.Grain refiners have a different effect on porosity formation of Al-Si alloys with regard to their solidification morphology.
