This paper presents a study of the isolation performance of trenches on train-induced ground-bore vibration from underground tunnels.A series of model tests was conducted to perform the study.Both train loads and sinu...This paper presents a study of the isolation performance of trenches on train-induced ground-bore vibration from underground tunnels.A series of model tests was conducted to perform the study.Both train loads and sinusoidal sweep loads were applied to the model tunnel invert by a shaker.The response of the soil at the surface of the ground was measured by accelerometers.Three types of isolation trenches,i.e.,an open trench,an expanded Polystyrene(EPS)-filled trench,and a Duxseal-filled trench,were modelled in the experiment.The results showed that the open trench and the EPS-filled trench increased the dynamic response of the surface soil in front of the trench,but the Duxseal-filled trench had little effect on the dynamic response of the soil on the surface in this area.Although all three types of isolation trenches reduced the response of the soil behind the trench,the open trench and the Duxseal-filled trench were clearly more effective.The test results also showed that,as the excitation frequency increased,the vibration isolation trench was more effective in the near field.The effects of the width,depth,and position of an open trench on isolation performance also were examined in the tests.展开更多
The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power ha...The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar cells.The results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar cells.Furthermore,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell performance.Based on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.展开更多
基金Supported by National Key R&D Program of China under Grant No.2016YFC0802210the National Natural Science Foundation of China under Grant Nos.51678499 and 51408494。
文摘This paper presents a study of the isolation performance of trenches on train-induced ground-bore vibration from underground tunnels.A series of model tests was conducted to perform the study.Both train loads and sinusoidal sweep loads were applied to the model tunnel invert by a shaker.The response of the soil at the surface of the ground was measured by accelerometers.Three types of isolation trenches,i.e.,an open trench,an expanded Polystyrene(EPS)-filled trench,and a Duxseal-filled trench,were modelled in the experiment.The results showed that the open trench and the EPS-filled trench increased the dynamic response of the surface soil in front of the trench,but the Duxseal-filled trench had little effect on the dynamic response of the soil on the surface in this area.Although all three types of isolation trenches reduced the response of the soil behind the trench,the open trench and the Duxseal-filled trench were clearly more effective.The test results also showed that,as the excitation frequency increased,the vibration isolation trench was more effective in the near field.The effects of the width,depth,and position of an open trench on isolation performance also were examined in the tests.
基金supported by the Doctoral Research Foundation of Southwest University of Science and Technology (Grant No.10zx7102)the National Natural Science Foundation of China (Grant No.11104226)
文摘The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar cells.The results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar cells.Furthermore,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell performance.Based on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.
