To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting...To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting methods and their interac- tion with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation of F You 498, a middle-season hybrid rice variety, under field conditions in 2012 and 2013. The results showed that there was a marked effect of the sowing and transplanting methods and their interaction with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation. The total population dry matter accumulation of the treatments with mechanical direct seeding （MDS） and machine-based transplanting （MT） was lower than that of the treatment with traditional manual transplanting （TMT）. How- ever, MDS had higher dry matter accumulation and accumulating rate in the joint- ing-earing stage,and maintained higher stem-sheath exportation, export rate and transformation than MT and TMT; MT had higher dry matter accumulation and ac- cumulating rate in the heading-maturity period than MDS and TMT. Moreover, the treatments with low seedling number per hill or early seeding enhanced the assimi- lation of dry matter after heading,the ratio of dry matter accumulation after earing to biomass yield and the contribution rate of dry matter accumulation after earing, and a reasonable early sowing was favorable to increase the harvest index of middle- season hybrid rice under mechanical sowing and transplanting conditions.展开更多
This article is devoted to the thermophysical and mechanical study of an eco-material, poto-poto. The objective is to study the influence of the addition of bamboo fibers on the thermophysical properties of the materi...This article is devoted to the thermophysical and mechanical study of an eco-material, poto-poto. The objective is to study the influence of the addition of bamboo fibers on the thermophysical properties of the material, while verifying that it complies with the mechanical standards in Cameroon. A double study is therefore carried out: a mechanical characterization whose objective is to determine the mechanical properties (compressive strength, flexural strength and Young’s modulus) and a thermophysical characterization whose objective is to determine the thermal conductivity. For the thermophysical characterization, the asymmetric hot plane experimental setup based on 1D quadrupole modelling was developed and simulated for the estimation of thermal effusivity E and volume heat capacity ρCp. The obtained experimental results show that the apparent thermal conductivity of the developed materials decreases with increasing fibers. Although the reference material (0% fibers) has a much higher conductivity than the ordinary sand block (1.15 Wm<sup>-1</sup> K<sup>-1</sup>), the addition of fibers, already at 2%, contributes to decrease this conductivity (0.95 Wm<sup>-1</sup> K<sup>-1</sup>). From the point of view of thermal insulation and energy savings, the thermal conductivity results obtained show that the use of these materials with a maximum fibercontent of 6% would be a better thermal insulator than sand block or compressed earth brick. The compressive strength obtained is such that Rc > 0.6 MPa. All the materials developed meet the design standards when used as infill.展开更多
目的对空心螺钉与重建钢板固定耻骨联合分离的生物力学性能进行测试,为临床应用提供理论依据。方法取温州医学院防腐正常成人骨盆标本15具,随机分成3组。自第5腰椎水平及双大腿中上2/3处将尸体横断。耻骨联合处切开,并将单侧骶棘韧带、...目的对空心螺钉与重建钢板固定耻骨联合分离的生物力学性能进行测试,为临床应用提供理论依据。方法取温州医学院防腐正常成人骨盆标本15具,随机分成3组。自第5腰椎水平及双大腿中上2/3处将尸体横断。耻骨联合处切开,并将单侧骶棘韧带、骶结节韧带、骶髂前韧带切断,模拟Tile B1型骨盆骨折,依次分别采用5孔重建钢板和6.5 mm空心螺钉内固定治疗耻骨联合分离。将标本固定于生物力学试验机,在腰5椎体上方对其进行垂直轴向压缩生物力学测试,最大负荷达400 N,比较耻骨联合分离的位移程度。结果 3.5 mm 5孔重建钢板和空心螺钉固定,均可显著减少耻骨联合的分离,恢复骨盆环的力学稳定性。其中3.5 mm 5孔重建钢板加4枚皮质骨螺钉于耻骨联合上方固定组,耻骨联合位移为(0.944±0.983)mm,空心螺钉髓内固定组耻骨联合分离为(-0.03±0.378)mm,两者之间存在统计学显著性差异(P<0.05)。结论空心螺钉在生物力学稳定性上优于5孔3.5 mm重建钢板。空心螺钉具有良好的生物力学性能,固定可靠,符合生物学固定的原则。展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303129)National Science and Technology Project for Bump Crop(2011BAD16B05)Scientific Research Foundation of Sichuan Agricultural University~~
文摘To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting methods and their interac- tion with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation of F You 498, a middle-season hybrid rice variety, under field conditions in 2012 and 2013. The results showed that there was a marked effect of the sowing and transplanting methods and their interaction with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation. The total population dry matter accumulation of the treatments with mechanical direct seeding （MDS） and machine-based transplanting （MT） was lower than that of the treatment with traditional manual transplanting （TMT）. How- ever, MDS had higher dry matter accumulation and accumulating rate in the joint- ing-earing stage,and maintained higher stem-sheath exportation, export rate and transformation than MT and TMT; MT had higher dry matter accumulation and ac- cumulating rate in the heading-maturity period than MDS and TMT. Moreover, the treatments with low seedling number per hill or early seeding enhanced the assimi- lation of dry matter after heading,the ratio of dry matter accumulation after earing to biomass yield and the contribution rate of dry matter accumulation after earing, and a reasonable early sowing was favorable to increase the harvest index of middle- season hybrid rice under mechanical sowing and transplanting conditions.
文摘This article is devoted to the thermophysical and mechanical study of an eco-material, poto-poto. The objective is to study the influence of the addition of bamboo fibers on the thermophysical properties of the material, while verifying that it complies with the mechanical standards in Cameroon. A double study is therefore carried out: a mechanical characterization whose objective is to determine the mechanical properties (compressive strength, flexural strength and Young’s modulus) and a thermophysical characterization whose objective is to determine the thermal conductivity. For the thermophysical characterization, the asymmetric hot plane experimental setup based on 1D quadrupole modelling was developed and simulated for the estimation of thermal effusivity E and volume heat capacity ρCp. The obtained experimental results show that the apparent thermal conductivity of the developed materials decreases with increasing fibers. Although the reference material (0% fibers) has a much higher conductivity than the ordinary sand block (1.15 Wm<sup>-1</sup> K<sup>-1</sup>), the addition of fibers, already at 2%, contributes to decrease this conductivity (0.95 Wm<sup>-1</sup> K<sup>-1</sup>). From the point of view of thermal insulation and energy savings, the thermal conductivity results obtained show that the use of these materials with a maximum fibercontent of 6% would be a better thermal insulator than sand block or compressed earth brick. The compressive strength obtained is such that Rc > 0.6 MPa. All the materials developed meet the design standards when used as infill.
文摘目的对空心螺钉与重建钢板固定耻骨联合分离的生物力学性能进行测试,为临床应用提供理论依据。方法取温州医学院防腐正常成人骨盆标本15具,随机分成3组。自第5腰椎水平及双大腿中上2/3处将尸体横断。耻骨联合处切开,并将单侧骶棘韧带、骶结节韧带、骶髂前韧带切断,模拟Tile B1型骨盆骨折,依次分别采用5孔重建钢板和6.5 mm空心螺钉内固定治疗耻骨联合分离。将标本固定于生物力学试验机,在腰5椎体上方对其进行垂直轴向压缩生物力学测试,最大负荷达400 N,比较耻骨联合分离的位移程度。结果 3.5 mm 5孔重建钢板和空心螺钉固定,均可显著减少耻骨联合的分离,恢复骨盆环的力学稳定性。其中3.5 mm 5孔重建钢板加4枚皮质骨螺钉于耻骨联合上方固定组,耻骨联合位移为(0.944±0.983)mm,空心螺钉髓内固定组耻骨联合分离为(-0.03±0.378)mm,两者之间存在统计学显著性差异(P<0.05)。结论空心螺钉在生物力学稳定性上优于5孔3.5 mm重建钢板。空心螺钉具有良好的生物力学性能,固定可靠,符合生物学固定的原则。
