The expansive behaviors of the expensive concrete under different restraining conditions were systemically studied. The experimental results indicate that expansive deformation obviously increases before 10 days and t...The expansive behaviors of the expensive concrete under different restraining conditions were systemically studied. The experimental results indicate that expansive deformation obviously increases before 10 days and tends to be constant after 25 days regardless of the restraining conditions. The mixture ratio of expansive cement and restraining conditions are the main factors affecting expansive deformation. Self-stress can be obtained when the expansive deformation is restrained. The higher self-stress could be obtained when the expensive concrete is restrained by steel tube. For specimens under steel tube restraining, the wall thickness and the length of the steel tube have important influence on self-stress. Both the radial self-stress and axial self-stress in concrete core increase when wall thickness or length of the steel tube increases.展开更多
Objectives： The aim of this study was to investigate the effect of linalool in chronically stressed rats on their behaviour as related to depressive disorders and BDNF （brain-derived neurotropic factor） protein in ...Objectives： The aim of this study was to investigate the effect of linalool in chronically stressed rats on their behaviour as related to depressive disorders and BDNF （brain-derived neurotropic factor） protein in the hippocampus. Methods： Either Tween 80 or linalool （50, 160, 500 mg/kg） was intraperitonealty administered to rats, daily, for two weeks. Some rats were housed in home cages but the others were induced with chronic restrained stress （15 min daily）. At the end of the treatment, the rats were assessed for depressive-like behaviour using the forced swimming test. At the end of the behaviour test, the animals were immediately decapitated and the hippocampus of each animal was removed for the measurement of the BDNF protein by ELISA. Result： The immobility time was significantly increased （p 〈 0.05） but time of climbing was significantly decreased （p 〈 0.05）. The restrained rats treated with linalool, 500 mg/kg, displayed immobility times less than those of their controls （p 〈 0.05） while these rats showed significantly more climbing than in the control rats （p 〈 0.05）. Linalool showed no effect on the BDNF protein in the hippocampus. Conclusions： linalool decreases behaviour related to depressive disorders but it has no effect on the BDNF protein in chronic restrained stress.展开更多
Combining with the technology of self-compacting concrete, self-stressing concrete and concrete-filled steel tube, we can get self-compacting and self-stressing concrete-filled steel tube. In order to study the expans...Combining with the technology of self-compacting concrete, self-stressing concrete and concrete-filled steel tube, we can get self-compacting and self-stressing concrete-filled steel tube. In order to study the expansive mechanism of self-stressing concrete, the continuous observation of 47 days on six specimens was carried on. The specimens have different steel area to concrete area ratio. The expansive process in hoop and axial direction were studied, and the expansive mechanism was discussed too. The experimental results identify that the creep and elastic deformation take a large proportion in effective free expansion. The calculating formulas of self-stress in hoop and axial directions were presented here.展开更多
基金Funded by the NSFC (No.50578027)the Key Subject Foundation of Henan Province (No.504906)the Doctor Foundation of Henan Polytechnic University (No.B2009-2)
文摘The expansive behaviors of the expensive concrete under different restraining conditions were systemically studied. The experimental results indicate that expansive deformation obviously increases before 10 days and tends to be constant after 25 days regardless of the restraining conditions. The mixture ratio of expansive cement and restraining conditions are the main factors affecting expansive deformation. Self-stress can be obtained when the expansive deformation is restrained. The higher self-stress could be obtained when the expensive concrete is restrained by steel tube. For specimens under steel tube restraining, the wall thickness and the length of the steel tube have important influence on self-stress. Both the radial self-stress and axial self-stress in concrete core increase when wall thickness or length of the steel tube increases.
文摘Objectives： The aim of this study was to investigate the effect of linalool in chronically stressed rats on their behaviour as related to depressive disorders and BDNF （brain-derived neurotropic factor） protein in the hippocampus. Methods： Either Tween 80 or linalool （50, 160, 500 mg/kg） was intraperitonealty administered to rats, daily, for two weeks. Some rats were housed in home cages but the others were induced with chronic restrained stress （15 min daily）. At the end of the treatment, the rats were assessed for depressive-like behaviour using the forced swimming test. At the end of the behaviour test, the animals were immediately decapitated and the hippocampus of each animal was removed for the measurement of the BDNF protein by ELISA. Result： The immobility time was significantly increased （p 〈 0.05） but time of climbing was significantly decreased （p 〈 0.05）. The restrained rats treated with linalool, 500 mg/kg, displayed immobility times less than those of their controls （p 〈 0.05） while these rats showed significantly more climbing than in the control rats （p 〈 0.05）. Linalool showed no effect on the BDNF protein in the hippocampus. Conclusions： linalool decreases behaviour related to depressive disorders but it has no effect on the BDNF protein in chronic restrained stress.
基金the National Natural Science Foundation of China (50578027)
文摘Combining with the technology of self-compacting concrete, self-stressing concrete and concrete-filled steel tube, we can get self-compacting and self-stressing concrete-filled steel tube. In order to study the expansive mechanism of self-stressing concrete, the continuous observation of 47 days on six specimens was carried on. The specimens have different steel area to concrete area ratio. The expansive process in hoop and axial direction were studied, and the expansive mechanism was discussed too. The experimental results identify that the creep and elastic deformation take a large proportion in effective free expansion. The calculating formulas of self-stress in hoop and axial directions were presented here.
