The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model unce...The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model uncertain, is much more complex than conventional nero-fin control. A novel nonlinear backstepping control approach is proposed to design the blended autopilot. Missile model is reformed to a new one by state reconstruction technique so that it is easy to be handled by the backstepping method. Then a Lyapunov function is chosen to avoid oscillation caused in normal backstepping way when control parameters are mismatched. In distribution of both inputs, optimal energy logic is proposed. In addition, a fuzzy cerebellar model articulation controller （FCMAC） neural network is used to guarantee controller robustness to uncertainties. Finally, simulation results demonstrate the efficiency and advantages of the proposed method.展开更多
Data on all drilled wells were analyzed for comparison of the effect of different bit types, weight on bit, and rotary speeds on the penetration rate in the various formations and depth intervals. This was initiated i...Data on all drilled wells were analyzed for comparison of the effect of different bit types, weight on bit, and rotary speeds on the penetration rate in the various formations and depth intervals. This was initiated in an attempt to improve penetration rates and reduce per well drilling times. Based on this study, an optimum bit selection, bit weight and rotary speed program was incorporated into drilling plans for subsequent wells drilled in the area. Initiation of this study resulted in significant improvement in penetration rates, in spite of the fact that some adverse conditions existed, such as formations, which have been pressure depleted by production, and drilling of high angle holes.展开更多
Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1...Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1977, Klimov, according to the light-dark differential spectrum of photosystem Ⅱ particles and the kinetic behavior of absorption and of fluorescence intensity change at 685 nm, concluded that pheo- phytin (Pheo) was the primary electron acceptor of photosystem Ⅱ. This report attracts much interest of workers to search the evidence of pheophytin as primary elec- tron acceptor in photosynthetic process.展开更多
This study examines the daylight and energy performance of 27 external shading scenarios in a high-rise residential building in the urban tropics.The cooling energy,daytime lighting energy and the spatial daylight aut...This study examines the daylight and energy performance of 27 external shading scenarios in a high-rise residential building in the urban tropics.The cooling energy,daytime lighting energy and the spatial daylight autonomy(sDA)of the building model were simulated in Rhino3D and Grasshopper simulation software.The best per-formance scenario(vertical and horizontal shading on the twentieth floor,horizontal shading only for the eleventh floor and no shading for the second floor)satisfied 75 sDA(300lx|50)with corresponding annual enery performance of 16%-20%in the cardinal directions.The baseline scenario,which is the current practice of providing balconies on all floors,reduced daylight to less than 75 sDA on the eleventh and second floor,even though it had higher annual enery performance(19%-24%)than the best performance scenario.Application of the design principles to a case study indicated that 58%of the spaces had over 75 sDA for both Baseline and Best per-formance scenarios,while an increase in enery performance of 1%-3%was found in the Best performance scenario compared to the Baseline.展开更多
基金the China Aviation Science Foundation (03D12004)
文摘The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model uncertain, is much more complex than conventional nero-fin control. A novel nonlinear backstepping control approach is proposed to design the blended autopilot. Missile model is reformed to a new one by state reconstruction technique so that it is easy to be handled by the backstepping method. Then a Lyapunov function is chosen to avoid oscillation caused in normal backstepping way when control parameters are mismatched. In distribution of both inputs, optimal energy logic is proposed. In addition, a fuzzy cerebellar model articulation controller （FCMAC） neural network is used to guarantee controller robustness to uncertainties. Finally, simulation results demonstrate the efficiency and advantages of the proposed method.
文摘Data on all drilled wells were analyzed for comparison of the effect of different bit types, weight on bit, and rotary speeds on the penetration rate in the various formations and depth intervals. This was initiated in an attempt to improve penetration rates and reduce per well drilling times. Based on this study, an optimum bit selection, bit weight and rotary speed program was incorporated into drilling plans for subsequent wells drilled in the area. Initiation of this study resulted in significant improvement in penetration rates, in spite of the fact that some adverse conditions existed, such as formations, which have been pressure depleted by production, and drilling of high angle holes.
文摘Although it is well known that there are two photosystems catalyzing different photochemical reactions in the chloroplast thylakoid membrane of higher plants, yet the components of these systems are not so clear. In 1977, Klimov, according to the light-dark differential spectrum of photosystem Ⅱ particles and the kinetic behavior of absorption and of fluorescence intensity change at 685 nm, concluded that pheo- phytin (Pheo) was the primary electron acceptor of photosystem Ⅱ. This report attracts much interest of workers to search the evidence of pheophytin as primary elec- tron acceptor in photosynthetic process.
文摘This study examines the daylight and energy performance of 27 external shading scenarios in a high-rise residential building in the urban tropics.The cooling energy,daytime lighting energy and the spatial daylight autonomy(sDA)of the building model were simulated in Rhino3D and Grasshopper simulation software.The best per-formance scenario(vertical and horizontal shading on the twentieth floor,horizontal shading only for the eleventh floor and no shading for the second floor)satisfied 75 sDA(300lx|50)with corresponding annual enery performance of 16%-20%in the cardinal directions.The baseline scenario,which is the current practice of providing balconies on all floors,reduced daylight to less than 75 sDA on the eleventh and second floor,even though it had higher annual enery performance(19%-24%)than the best performance scenario.Application of the design principles to a case study indicated that 58%of the spaces had over 75 sDA for both Baseline and Best per-formance scenarios,while an increase in enery performance of 1%-3%was found in the Best performance scenario compared to the Baseline.
