An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required fo...An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required for the galvanizing process. This paper assesses the effect on the joint strength of the angle between the brace members and the chord in a K- or N-joints made with rectangular hollow sections. The study is focused on the case when those brace members include characteristic holes required for the hot-dip galvanizing process. To accomplish the objective of the proposed work, some tests on full-scale K- and N-joints, including angles of 35°, 45°, 55° and 90°, were carried out. The experimental work was complemented by a validated numerical simulation in order to give some design recommendations and to extend the research to other joint configurations.展开更多
The venom apparatus in the large carpenter bees, Xylocopafenestrata （Fabricius） （Hymenoptera： Apidae） has been studied It consists of typical parts, i.e., the venom sac, free filament, Dufour gland, sting shaft a...The venom apparatus in the large carpenter bees, Xylocopafenestrata （Fabricius） （Hymenoptera： Apidae） has been studied It consists of typical parts, i.e., the venom sac, free filament, Dufour gland, sting shaft and accessory sclerites. It is highly sclerotized and concealed by the 7th abdominal tergite and sternite. The venom sac serves as a reservoir for the venom which synthesized by the convoluted gland present in it, which is remarkably uniform to that of ants. The median duct extends from lower portion of venom sac, which measures 2.5 ±0.17 mm （mean ＋ SD） （n = 20） in length. The Dufour gland is a tube-like structure which is inserted in the sting-bulb. The triangular plate is attached at terminal portion of rami, which is in turn attached with lancets. The gonostyli are paired long and tubular structure with 5.29 ± 0.23 mm （n = 20） in length. The sting length is 5.29 ±0.23 mm （n = 20）. The fulcral arm is well-developed with an inverse Y-shaped structure present beneath the sting-bulb. Barbs on the sting shaft are weakly developed in X fenestrata but well developed in ants. The venom apparatus ofX. fenestrata when compared is similar to the bees but differs from that of the wasps and ants.展开更多
文摘An important consideration when using hot-dip galvanized tubular structures is the uncertainty of the joint behaviour due to the possible reduction in the global joint resistance produced by the vent holes required for the galvanizing process. This paper assesses the effect on the joint strength of the angle between the brace members and the chord in a K- or N-joints made with rectangular hollow sections. The study is focused on the case when those brace members include characteristic holes required for the hot-dip galvanizing process. To accomplish the objective of the proposed work, some tests on full-scale K- and N-joints, including angles of 35°, 45°, 55° and 90°, were carried out. The experimental work was complemented by a validated numerical simulation in order to give some design recommendations and to extend the research to other joint configurations.
文摘The venom apparatus in the large carpenter bees, Xylocopafenestrata （Fabricius） （Hymenoptera： Apidae） has been studied It consists of typical parts, i.e., the venom sac, free filament, Dufour gland, sting shaft and accessory sclerites. It is highly sclerotized and concealed by the 7th abdominal tergite and sternite. The venom sac serves as a reservoir for the venom which synthesized by the convoluted gland present in it, which is remarkably uniform to that of ants. The median duct extends from lower portion of venom sac, which measures 2.5 ±0.17 mm （mean ＋ SD） （n = 20） in length. The Dufour gland is a tube-like structure which is inserted in the sting-bulb. The triangular plate is attached at terminal portion of rami, which is in turn attached with lancets. The gonostyli are paired long and tubular structure with 5.29 ± 0.23 mm （n = 20） in length. The sting length is 5.29 ±0.23 mm （n = 20）. The fulcral arm is well-developed with an inverse Y-shaped structure present beneath the sting-bulb. Barbs on the sting shaft are weakly developed in X fenestrata but well developed in ants. The venom apparatus ofX. fenestrata when compared is similar to the bees but differs from that of the wasps and ants.
