According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. Acco...According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. According to the model, the stresses of three tunnels and single tunnel are calculated and compared to analyze the distribution characteristics, where the stresses are influenced by controlling factors of clear distance, covering depth and inclination angle of ground surface. The results show that, in general, the bias distribution is more serious. Therefore, it is significant to settle down the load model of three shallow tunnels so as to determine the measure of reinforcement and design the structure of support. The model and results can be used as a theoretical basis in designation and further research of the three shallow tunnels.展开更多
A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has ...A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has the function of nitrification and removing organic substrate. In this study, we focused on the denitrification performance of LBAF and its possible mechanism under thorough aeration. We identified the existence of simultaneous nitrification and denitrification (SND) by analyzing nitrogenous compounds along the flow path of LBAF and supportive microbial microscopy, and studied the effects of air/water ratio and hydraulic loading on the performance of nitrogen removal and on SND in LBAF to find out the optimal operation condition. It is found that for saving operation cost, aeration can be reduced to some degree that allows desirable removal efficiency of pollutants, and the optimal air/water ratio is 10:1. Hydraulic loading less than 0.43 m h?1 hardly affects the nitrification and denitrification performance; whereas higher hydraulic loading is unfavorable to both nitrification and denitrification, far more unfavorable to denitrification than to nitrification.展开更多
我厂两台机组均为燃气—蒸汽联合循环发电机组。其中蒸汽轮机是由燃气轮机做功后排出的高温烟气经过余热锅炉加热炉水, 产生的蒸汽进入进行做功。为保证机组循环效率,汽轮机采用滑压运行方式,将余热锅炉产生的蒸汽全部送入汽轮机做功。...我厂两台机组均为燃气—蒸汽联合循环发电机组。其中蒸汽轮机是由燃气轮机做功后排出的高温烟气经过余热锅炉加热炉水, 产生的蒸汽进入进行做功。为保证机组循环效率,汽轮机采用滑压运行方式,将余热锅炉产生的蒸汽全部送入汽轮机做功。而 IPC 控制是 Mark VI 控制系统对于汽轮机进气压力的一种控制逻辑。展开更多
In order to evaluate the seismic behavior of confined RC column-composite beam joints, five interior joints were tested under low cyclic reversed load. The weakening extent of flanges, the number of studs, and whether...In order to evaluate the seismic behavior of confined RC column-composite beam joints, five interior joints were tested under low cyclic reversed load. The weakening extent of flanges, the number of studs, and whether to reinforce weakened flanges were used as parameters in designing these five joints. Failure characteristics, hysteretic curves, skeleton curves, ductility, energy dissipation, strength degradation, and stiffness degradation were analyzed. The test results revealed that the steel beam flanges in the joints were equivalent to the tie rod. Weakened flanges resulted in poor seismic behavior; however, the seismic behavior could be improved by increasing studs and reinforcing weakened flanges. The joint steel plate hoops, equivalent to stirrups, did not yield when the maximum load was reached, but yielded when the failure load was reached for the joints with shear failure. Increasing stud-type joints and reinforcing flange-type joints ensured good seismic behavior and met project requirements. Based on the experimental results, the failure mechanism of the joints was discussed, and the shear capacity equations of the joints was presented.展开更多
Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operati...Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operations, human safety and preventing the damage of port equipment and furniture. Therefore, this study discusses moored ship motions due to severe wind-wave during the tropical cyclone Linda which entered the Gulf of Thailand in November 1997. The ship motions are represented in the moored ship analysis at SRH （Sriracha Harbour Port） and BLCP （BLCP Coal-Fired Power Plant Port）, and are subject to the static environmental load on the ship in accordance with Spanish Standard （ROM 0.2-1990） [1]. The environment in numerical model is derived from the wave model and hydrodynamics model using the application of Delft3D-WAVE and Delft3D-FLOW. The model location includes Ao Udom Bay and Rayong Sea. The model results represent the environment at Rayong Sea which is more severe than Ao Udom Bay. The ship motions at BLCP are mostly larger than SRH.展开更多
Human serum albumin(HSA)is the most abundant plasma protein and has an inherent ability to target tumor cells.It is an excellent candidate for drug delivery.However,HSA cannot form complex with DNA or RNA,because it i...Human serum albumin(HSA)is the most abundant plasma protein and has an inherent ability to target tumor cells.It is an excellent candidate for drug delivery.However,HSA cannot form complex with DNA or RNA,because it is negatively charged under physiological conditions.In this work,we reported a simple method to prepare HSA/RNA nanoparticles mainly by physical interaction.Firstly,the solution p H is adjusted to 4.0,under which condition HSA is positively charged.It forms complex with RNA via electrostatic interaction.The solution is then heated at 75 oC for 15 min to stabilize the structure and the size of the formed complex.The HSA/RNA nanoparticle prepared by this method has a diameter about 110 nm and a narrow distribution.It is also stable for days under physiological conditions.Cellular essays demonstrate that these particles exhibit a high cellular uptake efficiency and non-toxicity to He La cells.展开更多
To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then ...To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then withdrawn for several days by aortic debanding,followed by subsequent myocardial exposure to ischemia/reperfusion(I/R).Following I/R injury,the myocardial infarct size and apoptosis were markedly reduced,and contractile function was significantly improved in the TAC preconditioning group compared with the control group.Mechanistically,hypertrophic preconditioning remarkably alleviated I/R-induced oxidative stress,as evidenced by the increased reduced nicotinamide adenine dinucleotide phosphate(NADPH)/nicotinamide adenine dinucleotide phosphate(NADP)ratio,increase in the reduced glutathione(GSH)/oxidized glutathione(GSSH)ratio,and reduced mitochondrial reactive oxygen species(ROS)production.Moreover,TAC preconditioning inhibited caspase-3 activation and mitigated the mitochondrial impairment by deacetylating isocitrate dehydrogenase 2(IDH2)via a sirtuin 3(SIRT3)-dependent mechanism.In addition,the expression of a genetic deacetylation mimetic IDH2 mutant(IDH2 K413R)in cardiomyocytes,which increased IDH2 enzymatic activity and decreased mitochondrial ROS production,and ameliorated I/R injury,whereas the expression of a genetic acetylation mimetic(IDH2 K413Q)in cardiomyocytes abolished these protective effects of hypertrophic preconditioning.Furthermore,both the activity and expression of the SIRT3 protein were markedly increased in preconditioned mice exposed to I/R.Treatment with an adenovirus encoding SIRT3 partially emulated the actions of hypertrophic preconditioning,whereas genetic ablation of SIRT3 in mice blocked the cardioprotective effects of hypertrophic preconditioning.The present study identifies hypertrophic preconditioning as a novel endogenous self-defensive and cardioprotective strategy for cardiac I/R injury that induces IDH2 deacetylation through a SIRT3-dependent mechanism.A therapeutic strategy targeting IDH2 may be a promising treatment for cardiac ischemic injury.展开更多
The effects of intertube additional atoms on （DWCNTs） are investigated using molecular dynamics （MD） the sliding behaviors of double-walled carbon nanotubes simulation method. The interaction between carbon atoms ...The effects of intertube additional atoms on （DWCNTs） are investigated using molecular dynamics （MD） the sliding behaviors of double-walled carbon nanotubes simulation method. The interaction between carbon atoms is modeled using the second-generation reactive empirical bond-order potential coupled with the Lennard-Jones potential. The simulations indicate that intertube additional atoms of DWCNT can significantly enhance the load transfer between neighboring tubes of DWCNT. The improvement in load transfer is guaranteed by the addition of intertube atoms which are covalently bonded to the inner and outer tubes of DWCNT. The results also show that the sliding behaviors of DWCNT are strongly dependent of additional atom numbers. The results presented here demonstrate that the superior mechanical properties of DWCNT can be realized by controlling intertube coupling. The general conclusions derived from this work may be of importance in devising high-performance CNT composites.展开更多
基金Projects(2013CB036004, 2011CB013800) supported by the National Basic Research Program of ChinaProject(51178468, 50908234) supported by the National Natural Science Foundation of ChinaProject(2011G103-B) supported by the Science and Technology Development of Railway in China
文摘According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. According to the model, the stresses of three tunnels and single tunnel are calculated and compared to analyze the distribution characteristics, where the stresses are influenced by controlling factors of clear distance, covering depth and inclination angle of ground surface. The results show that, in general, the bias distribution is more serious. Therefore, it is significant to settle down the load model of three shallow tunnels so as to determine the measure of reinforcement and design the structure of support. The model and results can be used as a theoretical basis in designation and further research of the three shallow tunnels.
基金Funded by the National Key Technologies R & D Program of China During the 10th Five-Year Plan Periods of China (No.2001BA604A01-03).
文摘A new wastewater treatment facility—lateral flow biological aerated filter (LBAF) was developed aiming at solving energy consumption and operational problems in wastewater treatment facilities in small towns. It has the function of nitrification and removing organic substrate. In this study, we focused on the denitrification performance of LBAF and its possible mechanism under thorough aeration. We identified the existence of simultaneous nitrification and denitrification (SND) by analyzing nitrogenous compounds along the flow path of LBAF and supportive microbial microscopy, and studied the effects of air/water ratio and hydraulic loading on the performance of nitrogen removal and on SND in LBAF to find out the optimal operation condition. It is found that for saving operation cost, aeration can be reduced to some degree that allows desirable removal efficiency of pollutants, and the optimal air/water ratio is 10:1. Hydraulic loading less than 0.43 m h?1 hardly affects the nitrification and denitrification performance; whereas higher hydraulic loading is unfavorable to both nitrification and denitrification, far more unfavorable to denitrification than to nitrification.
文摘我厂两台机组均为燃气—蒸汽联合循环发电机组。其中蒸汽轮机是由燃气轮机做功后排出的高温烟气经过余热锅炉加热炉水, 产生的蒸汽进入进行做功。为保证机组循环效率,汽轮机采用滑压运行方式,将余热锅炉产生的蒸汽全部送入汽轮机做功。而 IPC 控制是 Mark VI 控制系统对于汽轮机进气压力的一种控制逻辑。
基金Supported by the National Natural Science Foundation of China(No.51209094)
文摘In order to evaluate the seismic behavior of confined RC column-composite beam joints, five interior joints were tested under low cyclic reversed load. The weakening extent of flanges, the number of studs, and whether to reinforce weakened flanges were used as parameters in designing these five joints. Failure characteristics, hysteretic curves, skeleton curves, ductility, energy dissipation, strength degradation, and stiffness degradation were analyzed. The test results revealed that the steel beam flanges in the joints were equivalent to the tie rod. Weakened flanges resulted in poor seismic behavior; however, the seismic behavior could be improved by increasing studs and reinforcing weakened flanges. The joint steel plate hoops, equivalent to stirrups, did not yield when the maximum load was reached, but yielded when the failure load was reached for the joints with shear failure. Increasing stud-type joints and reinforcing flange-type joints ensured good seismic behavior and met project requirements. Based on the experimental results, the failure mechanism of the joints was discussed, and the shear capacity equations of the joints was presented.
文摘Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operations, human safety and preventing the damage of port equipment and furniture. Therefore, this study discusses moored ship motions due to severe wind-wave during the tropical cyclone Linda which entered the Gulf of Thailand in November 1997. The ship motions are represented in the moored ship analysis at SRH （Sriracha Harbour Port） and BLCP （BLCP Coal-Fired Power Plant Port）, and are subject to the static environmental load on the ship in accordance with Spanish Standard （ROM 0.2-1990） [1]. The environment in numerical model is derived from the wave model and hydrodynamics model using the application of Delft3D-WAVE and Delft3D-FLOW. The model location includes Ao Udom Bay and Rayong Sea. The model results represent the environment at Rayong Sea which is more severe than Ao Udom Bay. The ship motions at BLCP are mostly larger than SRH.
基金the National Natural Science Foundation of China (21574002)
文摘Human serum albumin(HSA)is the most abundant plasma protein and has an inherent ability to target tumor cells.It is an excellent candidate for drug delivery.However,HSA cannot form complex with DNA or RNA,because it is negatively charged under physiological conditions.In this work,we reported a simple method to prepare HSA/RNA nanoparticles mainly by physical interaction.Firstly,the solution p H is adjusted to 4.0,under which condition HSA is positively charged.It forms complex with RNA via electrostatic interaction.The solution is then heated at 75 oC for 15 min to stabilize the structure and the size of the formed complex.The HSA/RNA nanoparticle prepared by this method has a diameter about 110 nm and a narrow distribution.It is also stable for days under physiological conditions.Cellular essays demonstrate that these particles exhibit a high cellular uptake efficiency and non-toxicity to He La cells.
基金supported by the National Natural Science Foundation of China(81870290,81521001,81800235,and 81800238)。
文摘To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then withdrawn for several days by aortic debanding,followed by subsequent myocardial exposure to ischemia/reperfusion(I/R).Following I/R injury,the myocardial infarct size and apoptosis were markedly reduced,and contractile function was significantly improved in the TAC preconditioning group compared with the control group.Mechanistically,hypertrophic preconditioning remarkably alleviated I/R-induced oxidative stress,as evidenced by the increased reduced nicotinamide adenine dinucleotide phosphate(NADPH)/nicotinamide adenine dinucleotide phosphate(NADP)ratio,increase in the reduced glutathione(GSH)/oxidized glutathione(GSSH)ratio,and reduced mitochondrial reactive oxygen species(ROS)production.Moreover,TAC preconditioning inhibited caspase-3 activation and mitigated the mitochondrial impairment by deacetylating isocitrate dehydrogenase 2(IDH2)via a sirtuin 3(SIRT3)-dependent mechanism.In addition,the expression of a genetic deacetylation mimetic IDH2 mutant(IDH2 K413R)in cardiomyocytes,which increased IDH2 enzymatic activity and decreased mitochondrial ROS production,and ameliorated I/R injury,whereas the expression of a genetic acetylation mimetic(IDH2 K413Q)in cardiomyocytes abolished these protective effects of hypertrophic preconditioning.Furthermore,both the activity and expression of the SIRT3 protein were markedly increased in preconditioned mice exposed to I/R.Treatment with an adenovirus encoding SIRT3 partially emulated the actions of hypertrophic preconditioning,whereas genetic ablation of SIRT3 in mice blocked the cardioprotective effects of hypertrophic preconditioning.The present study identifies hypertrophic preconditioning as a novel endogenous self-defensive and cardioprotective strategy for cardiac I/R injury that induces IDH2 deacetylation through a SIRT3-dependent mechanism.A therapeutic strategy targeting IDH2 may be a promising treatment for cardiac ischemic injury.
基金Supported by the National Natural Science Foundation of China under Grant No.10902083the Program for New Scientific and Technological Star of Shaanxi Province under Grant No.2012KJXX-39
文摘The effects of intertube additional atoms on （DWCNTs） are investigated using molecular dynamics （MD） the sliding behaviors of double-walled carbon nanotubes simulation method. The interaction between carbon atoms is modeled using the second-generation reactive empirical bond-order potential coupled with the Lennard-Jones potential. The simulations indicate that intertube additional atoms of DWCNT can significantly enhance the load transfer between neighboring tubes of DWCNT. The improvement in load transfer is guaranteed by the addition of intertube atoms which are covalently bonded to the inner and outer tubes of DWCNT. The results also show that the sliding behaviors of DWCNT are strongly dependent of additional atom numbers. The results presented here demonstrate that the superior mechanical properties of DWCNT can be realized by controlling intertube coupling. The general conclusions derived from this work may be of importance in devising high-performance CNT composites.
