提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±...提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±800 k V输电系统技术经济评估。1 000 k V和±800 k V输电系统,输电距离1 500±2 000 km,按静态(热)稳定输送功率,单位输电建设成本处于相同水平;1 000 k V输电系统的年运行成本明显低于±800 k V输电系统。1 000 k V输电系统暂态稳定输送功率的单位输电建设成本也明显低于±800 k V输电系统。1000 k V输电系统经济性优于±800 k V输电系统。展开更多
A beam stabilization algorithm was proposed for low cost satcom-on-the-move （SOTM） to stabilize the vehicle-mounted antenna beam. The proposed algorithm utilizes the nonlinear observel to estimate the vehicle＇s att...A beam stabilization algorithm was proposed for low cost satcom-on-the-move （SOTM） to stabilize the vehicle-mounted antenna beam. The proposed algorithm utilizes the nonlinear observel to estimate the vehicle＇s attitude information based on inertial measurement unit. Then the estimated angles and angular velocities are used to stabilize the antenna beam. Experiment results show tha｜ the proposed algorithm can stabilize the antenna beam when the tracking information is available, indicating that it is competent to the SOTM system.展开更多
Sexual deception involves the mimicry of another species＇ sexual signals in order to exploit behavioural routines linked to those signals. Known sexually deceptive systems use visual, acoustic or olfactory mimicry to...Sexual deception involves the mimicry of another species＇ sexual signals in order to exploit behavioural routines linked to those signals. Known sexually deceptive systems use visual, acoustic or olfactory mimicry to exploit insects for preda- tion, cleptoparasitism and pollination. It is predicted that where sexual deception inflicts a cost on the receiver, a coevolutionary arms race could result in the evolution of discriminating receivers and increasingly refined mimicry. We constructed a conceptual model to understand the importance of trade-offs in the coevolution of sexually deceptive mimic and receiver. Four components examined were： the cost of mimicry, the cost to receiver for being fooled, the density of mimics and the relative magnitude of a mimicry-independent component of fitness. The model predicts that the exploitation of non-discriminating receivers by accurate signal mimicry will evolve as an evolutionary stable strategy under a wide range of the parameter space explored. This is due to the difficulty in minimising the costs of being fooled without incurring the cost of falsely rejecting real mating opportunities. In the model, the evolution of deception is impeded when mimicry imposes substantial costs for both sides of the arms race. Olfac- tory signals that are potentially cheap to produce are therefore likely to be more vulnerable to exploitation than expensive visual ornaments展开更多
文摘提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±800 k V输电系统技术经济评估。1 000 k V和±800 k V输电系统,输电距离1 500±2 000 km,按静态(热)稳定输送功率,单位输电建设成本处于相同水平;1 000 k V输电系统的年运行成本明显低于±800 k V输电系统。1 000 k V输电系统暂态稳定输送功率的单位输电建设成本也明显低于±800 k V输电系统。1000 k V输电系统经济性优于±800 k V输电系统。
基金This work was supported in part by the National Natural Science Foundation of China under grant numbers 61179004,61179005 and 61401471
文摘A beam stabilization algorithm was proposed for low cost satcom-on-the-move （SOTM） to stabilize the vehicle-mounted antenna beam. The proposed algorithm utilizes the nonlinear observel to estimate the vehicle＇s attitude information based on inertial measurement unit. Then the estimated angles and angular velocities are used to stabilize the antenna beam. Experiment results show tha｜ the proposed algorithm can stabilize the antenna beam when the tracking information is available, indicating that it is competent to the SOTM system.
文摘Sexual deception involves the mimicry of another species＇ sexual signals in order to exploit behavioural routines linked to those signals. Known sexually deceptive systems use visual, acoustic or olfactory mimicry to exploit insects for preda- tion, cleptoparasitism and pollination. It is predicted that where sexual deception inflicts a cost on the receiver, a coevolutionary arms race could result in the evolution of discriminating receivers and increasingly refined mimicry. We constructed a conceptual model to understand the importance of trade-offs in the coevolution of sexually deceptive mimic and receiver. Four components examined were： the cost of mimicry, the cost to receiver for being fooled, the density of mimics and the relative magnitude of a mimicry-independent component of fitness. The model predicts that the exploitation of non-discriminating receivers by accurate signal mimicry will evolve as an evolutionary stable strategy under a wide range of the parameter space explored. This is due to the difficulty in minimising the costs of being fooled without incurring the cost of falsely rejecting real mating opportunities. In the model, the evolution of deception is impeded when mimicry imposes substantial costs for both sides of the arms race. Olfac- tory signals that are potentially cheap to produce are therefore likely to be more vulnerable to exploitation than expensive visual ornaments
