The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation...The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental mod...The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental modal analysis method. Meanwhile,carbon fiber plain woven laminated / epoxy resin composites with different fiber volume fraction were concerned for comparison. The experimental result of braided specimens shows that the first three orders of natural frequency increase and the first three orders of the damping ratios of specimens decrease, when the fiber volume fraction increases. Furthermore,larger fiber volume fraction will be valuable for the better anti-exiting property of braided composites,and get an opposite effect on dissipation of vibration energy. The fiber volume fraction is an important factor for vibration performance design of braided composites. The comparison between the braided specimens and laminated specimens reveals that 3D braided composites have a wider range of damping properties than laminated composites with the same fiber volume fractions.展开更多
Two 3-D numerical models of the discrete element method （DEM） for impact problems are proposed. The models can calculate not only the impact problems of continuum and non-continuum, but also the transient process fr...Two 3-D numerical models of the discrete element method （DEM） for impact problems are proposed. The models can calculate not only the impact problems of continuum and non-continuum, but also the transient process from continuum to non-continuum. The stress wave propagation in a concrete block and a dynamic splitting process of a marble disc under impact loading are numerically simulated with the proposed models. By comparing the numerical results with the corresponding results obtained by the finite element method （FEM） and the experiments, it is proved that the models are reliable for three-dimensional impact problems.展开更多
HIV/AIDS spread has opened a Pandora of medical and health problems apart from creating serious socio-psychological trauma for the victims and their families. Despite the governmental effort to curve the growing infec...HIV/AIDS spread has opened a Pandora of medical and health problems apart from creating serious socio-psychological trauma for the victims and their families. Despite the governmental effort to curve the growing infection, very little success has been achieved. The northeastern region of India presents a very peculiar situation due to recurrent insurgency in all its states for long time and thus it became instrumental in paralyzing the social and health machineries to an extent, which still deteriorated the futile national effort to check the deadly infection. The study tried to understand the level of awareness and correct knowledge among the underprivileged scheduled tribes and scheduled castes women in the age group 15 -44 by exploring data from district level of Rapid Household Reproductive and Child Health Project Phase I (1998) and Phase II (1999) for Assam, Manipur and Nagaland and suggested a strategy to control the infection in the region. It is found that HIV/AIDS awareness was 59% among the women in all the three states with very few among them who had correct understanding of its prevention. A pronounced difference in the level of awareness was observed with respect to age, economy and residential status of the respondents.展开更多
文摘The construction of the double-lane five-step ship lock of the Three Gorges Project （TGP） wascommenced in 1994, the excavation of the ship lock was completed by the end of 1999, and the ship lockwas put in operation in June 2003. The side slopes of the ship lock are characterized by great height（170 m）, steepness （70 m in height of upright slope）, and great length （over 7000 m in total length）. Inassociation with the ship lock, the surrounding rocks in slope have a high potential to deform, withwhich the magnitude of deformation is restricted. Monitoring results show that the deformation of thefive-step ship lock high slopes of the TGP primarily occurred in excavation period, and deformationtended to be stable and convergent during operation period, suggesting the allowable ranges of deformation.At present, the slopes and lock chambers are stable, and the ship lock works well under normaloperation condition, enabling the social and economic benefits of the TGP. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
基金Tianjin Municipal Science and Technologies Commission,China(Nos.10SYSYJC27800,1ZCKFSF00500)
文摘The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental modal analysis method. Meanwhile,carbon fiber plain woven laminated / epoxy resin composites with different fiber volume fraction were concerned for comparison. The experimental result of braided specimens shows that the first three orders of natural frequency increase and the first three orders of the damping ratios of specimens decrease, when the fiber volume fraction increases. Furthermore,larger fiber volume fraction will be valuable for the better anti-exiting property of braided composites,and get an opposite effect on dissipation of vibration energy. The fiber volume fraction is an important factor for vibration performance design of braided composites. The comparison between the braided specimens and laminated specimens reveals that 3D braided composites have a wider range of damping properties than laminated composites with the same fiber volume fractions.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10572002 and 10732010.
文摘Two 3-D numerical models of the discrete element method （DEM） for impact problems are proposed. The models can calculate not only the impact problems of continuum and non-continuum, but also the transient process from continuum to non-continuum. The stress wave propagation in a concrete block and a dynamic splitting process of a marble disc under impact loading are numerically simulated with the proposed models. By comparing the numerical results with the corresponding results obtained by the finite element method （FEM） and the experiments, it is proved that the models are reliable for three-dimensional impact problems.
文摘HIV/AIDS spread has opened a Pandora of medical and health problems apart from creating serious socio-psychological trauma for the victims and their families. Despite the governmental effort to curve the growing infection, very little success has been achieved. The northeastern region of India presents a very peculiar situation due to recurrent insurgency in all its states for long time and thus it became instrumental in paralyzing the social and health machineries to an extent, which still deteriorated the futile national effort to check the deadly infection. The study tried to understand the level of awareness and correct knowledge among the underprivileged scheduled tribes and scheduled castes women in the age group 15 -44 by exploring data from district level of Rapid Household Reproductive and Child Health Project Phase I (1998) and Phase II (1999) for Assam, Manipur and Nagaland and suggested a strategy to control the infection in the region. It is found that HIV/AIDS awareness was 59% among the women in all the three states with very few among them who had correct understanding of its prevention. A pronounced difference in the level of awareness was observed with respect to age, economy and residential status of the respondents.
