In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ（NSGA-Ⅱ） based traffic signal control optimization algorithm is prop...In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ（NSGA-Ⅱ） based traffic signal control optimization algorithm is proposed. The throughput maximum and average queue ratio minimum for the critical route of the intersection group are selected as the optimization objectives of the traffic signal control for the over-saturated condition. The consequences of the efficiency between traffic signal timing plans generated by the proposed algorithm and a commonly utilized signal timing optimization software Synchro are compared in a VISSIM signal control application programming interfaces （SCAPI） simulation environment by using real filed observed traffic data. The simulation results indicate that the signal timing plan generated by the proposed algorithm is more efficient in managing oversaturated flows at intersection groups, and, thus, it has the capability of optimizing signal timing under the over-saturated conditions.展开更多
Shape control has proven to be a powerful and versatile means of tailoring the properties of Bi2Se3 nanostructures for a wide variety of applications. Here, three different Bi2Se3 nanostructures, i.e., spiral-type nan...Shape control has proven to be a powerful and versatile means of tailoring the properties of Bi2Se3 nanostructures for a wide variety of applications. Here, three different Bi2Se3 nanostructures, i.e., spiral-type nanoplates, smooth nanoplates, and dendritic nanostructures, were prepared by manipulating the supersaturation level in the synthetic system. This mechanism study indicated that, at low supersaturation, defects in the crystal growth could cause a step edge upon which Bi2Se3 particles were added continuously, leading to the formation of spiral-type nanoplates. At intermediate supersaturation, the aggregation of amorphous Bi2Se3 particles and subsequent recrystallization resulted in the formation of smooth nanoplates. Furthermore, at high supersaturation, polycrystalline Bi2Se3 cores formed initially, on which anisotropic growth of Bi2Se3 occurred. This work not only advances our understanding of the growth mechanism but also offers a new approach to control the morphology of Bi2Se3 nanostructures.展开更多
基金The National Natural Science Foundation of China(No.51208054)
文摘In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ（NSGA-Ⅱ） based traffic signal control optimization algorithm is proposed. The throughput maximum and average queue ratio minimum for the critical route of the intersection group are selected as the optimization objectives of the traffic signal control for the over-saturated condition. The consequences of the efficiency between traffic signal timing plans generated by the proposed algorithm and a commonly utilized signal timing optimization software Synchro are compared in a VISSIM signal control application programming interfaces （SCAPI） simulation environment by using real filed observed traffic data. The simulation results indicate that the signal timing plan generated by the proposed algorithm is more efficient in managing oversaturated flows at intersection groups, and, thus, it has the capability of optimizing signal timing under the over-saturated conditions.
基金Acknowledgements This work was supported by Collaborative Innovation Center of Suzhou Nano Science and Technology, MOST of China （No. 2014CB932700）, 2015SRG-HSC049, National Natural Science Foundation of China （Nos. 21203173, 21573206, 11574281, 51371164, 51132007, and J1030412）, Strategic Priority Research Program B of the CAS （No. XDB01020000）, and Fundamental Research Funds for the Central Universities （Nos. WK2340000050, WK2060190025, and WK3510000002）.
文摘Shape control has proven to be a powerful and versatile means of tailoring the properties of Bi2Se3 nanostructures for a wide variety of applications. Here, three different Bi2Se3 nanostructures, i.e., spiral-type nanoplates, smooth nanoplates, and dendritic nanostructures, were prepared by manipulating the supersaturation level in the synthetic system. This mechanism study indicated that, at low supersaturation, defects in the crystal growth could cause a step edge upon which Bi2Se3 particles were added continuously, leading to the formation of spiral-type nanoplates. At intermediate supersaturation, the aggregation of amorphous Bi2Se3 particles and subsequent recrystallization resulted in the formation of smooth nanoplates. Furthermore, at high supersaturation, polycrystalline Bi2Se3 cores formed initially, on which anisotropic growth of Bi2Se3 occurred. This work not only advances our understanding of the growth mechanism but also offers a new approach to control the morphology of Bi2Se3 nanostructures.
