The lining of shield tunnel is usually composed of segments,in which the joints,cracks,and the grouting holes(hereafter called lining deficit)exist.During the long-term running,soils and groundwater may leak from thes...The lining of shield tunnel is usually composed of segments,in which the joints,cracks,and the grouting holes(hereafter called lining deficit)exist.During the long-term running,soils and groundwater may leak from these kinds of lining deficit.The leaking of soil and groundwater causes the long-term ground loss around tunnel and thus results in the settlement of ground surface.This paper aims to analyze the impact of the leakage of groundwater through segments on the long-term settlement of ground surface.The adopted analytical method is based on the theory of groundwater seepage by using numerical simulation.The analyzed results show that settlement of ground surface increases gradually with the increase of the leaked volume of tunnel segments.When the leaked volume was unevenly distributed,differential settlement occurred locally.Comparative analysis by changing the leaked volume was conducted.The results reveal that there is a linear relationship between settlement and leaked volume when the leaked volume was controlled within the allowable limit.展开更多
Perovskite solar cells with TiO_2 electron transport layers exhibit power conversion efficiency(PCE) as high as 22.7% in single cells. However, the preparation process of the TiO_2 layer is adopted by an unscalable me...Perovskite solar cells with TiO_2 electron transport layers exhibit power conversion efficiency(PCE) as high as 22.7% in single cells. However, the preparation process of the TiO_2 layer is adopted by an unscalable method or requires high-temperature sintering, which precludes its potential use for mass production of flexible devices. In this study, a scalable low-temperature softcover-assisted hydrolysis(SAH) method is presented,where the precursor solution is sandwiched between a soft cover and preheated substrate to form a closed hydrolysis environment. Compact homogeneous TiO_2 films with a needle-like structure were obtained after the hydrolysis of a TiCl_4 aqueous solution. Moreover, by careful optimization of the TiO_2 fabrication conditions, a high PCE of 14.01% could be achieved for a solar module(4 × 4 cm^2) prepared using the SAH method. This method provides a novel approach for the efficient scale-up of the low-temperature TiO_2 film growth for industrial applications.展开更多
The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density (Bs>2.1 T) and low coercivity (Hc) was investigated using cyclic voltammetry and chronoampero...The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density (Bs>2.1 T) and low coercivity (Hc) was investigated using cyclic voltammetry and chronoamperometry methods in conjunction with the scanning electron microscopy (SEM/EDX). The results show that, under the experimental conditions, the co-deposition of CoNiFe film behaves anomalously due to the atomic radii of iron series elements following the order of rFe>rCo>rNi. In the case of lower electroplating current density, the co-deposition of CoNiFe film follows a 3-D progressive nucleation/growth mechanism, while in the case of higher electroplating current density, which follows a 3-D instantaneous nucleation/growth mechanism. Meanwhile, the change of nucleation mechanism of CoNiFe film with electroplating current density was interpreted theoretically in the light of quantum chemistry.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41072209)the joint research program between NSFC and the Japan Society for the Promotion of Science(50911140105)+1 种基金Shanghai Leading Academic Discipline Project(Project Number:B208)the Innovative Self-selected Project of the State Key Laboratory of Ocean Engineering(GKZD010051).
文摘The lining of shield tunnel is usually composed of segments,in which the joints,cracks,and the grouting holes(hereafter called lining deficit)exist.During the long-term running,soils and groundwater may leak from these kinds of lining deficit.The leaking of soil and groundwater causes the long-term ground loss around tunnel and thus results in the settlement of ground surface.This paper aims to analyze the impact of the leakage of groundwater through segments on the long-term settlement of ground surface.The adopted analytical method is based on the theory of groundwater seepage by using numerical simulation.The analyzed results show that settlement of ground surface increases gradually with the increase of the leaked volume of tunnel segments.When the leaked volume was unevenly distributed,differential settlement occurred locally.Comparative analysis by changing the leaked volume was conducted.The results reveal that there is a linear relationship between settlement and leaked volume when the leaked volume was controlled within the allowable limit.
基金supported financially by the National Natural Science Foundation of China (Grants Nos. 11574199, 11674219)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning+1 种基金the Natural Science Foundation of Shanghai (17ZR1414800)the Baotou-SJTU innovation guidance fund Project (17H100000514)
文摘Perovskite solar cells with TiO_2 electron transport layers exhibit power conversion efficiency(PCE) as high as 22.7% in single cells. However, the preparation process of the TiO_2 layer is adopted by an unscalable method or requires high-temperature sintering, which precludes its potential use for mass production of flexible devices. In this study, a scalable low-temperature softcover-assisted hydrolysis(SAH) method is presented,where the precursor solution is sandwiched between a soft cover and preheated substrate to form a closed hydrolysis environment. Compact homogeneous TiO_2 films with a needle-like structure were obtained after the hydrolysis of a TiCl_4 aqueous solution. Moreover, by careful optimization of the TiO_2 fabrication conditions, a high PCE of 14.01% could be achieved for a solar module(4 × 4 cm^2) prepared using the SAH method. This method provides a novel approach for the efficient scale-up of the low-temperature TiO_2 film growth for industrial applications.
文摘The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density (Bs>2.1 T) and low coercivity (Hc) was investigated using cyclic voltammetry and chronoamperometry methods in conjunction with the scanning electron microscopy (SEM/EDX). The results show that, under the experimental conditions, the co-deposition of CoNiFe film behaves anomalously due to the atomic radii of iron series elements following the order of rFe>rCo>rNi. In the case of lower electroplating current density, the co-deposition of CoNiFe film follows a 3-D progressive nucleation/growth mechanism, while in the case of higher electroplating current density, which follows a 3-D instantaneous nucleation/growth mechanism. Meanwhile, the change of nucleation mechanism of CoNiFe film with electroplating current density was interpreted theoretically in the light of quantum chemistry.
