Beryllium (Be) window is a key component of the ITER radial X-ray camera (RXC). The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray thre...Beryllium (Be) window is a key component of the ITER radial X-ray camera (RXC). The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray threshold of the 80 μm Be foil is 1.24 keV. A honeycomb support is designed and applied to strengthen the Be foil to prevent it from breakage when it is exposed to 1 atm perssure. Based on analysis results, the hole diameter of the support is chosen as 4 mm. A metal seal is used to isolate the vacuum on two sides of the Be window, the hollow metal sealing ring ensures the He leakage rate of the Be window being lower than 6× 10^-1 Pa.m^3.s^-1. Baking (240 ℃, 2 h) and vibration(3.3 Hz, 2 h) tests are carried out and the feasibility of the Be window's sealant in these situations is tested. The Be window has good stability that can save maintenance cost as well as enhancing the safety of the RXC.展开更多
目前网约车拼车服务存在响应不及时、乘客舒适度低等现象,亟需对拼车路线及求解算法进行优化。本文首先考虑路网条件及时间窗阈值影响,以网约车运行成本与乘客出行成本最小化为目标,构建基于双向线路的网约车拼车优化模型("one-to-...目前网约车拼车服务存在响应不及时、乘客舒适度低等现象,亟需对拼车路线及求解算法进行优化。本文首先考虑路网条件及时间窗阈值影响,以网约车运行成本与乘客出行成本最小化为目标,构建基于双向线路的网约车拼车优化模型("one-to-many"online car-hailing carpooling model under multiple constraints)。其次以遗传算法为基础,结合模拟退火温度调控机制,改进适应度评价和接受准则,提出混合遗传-模拟退火算法(hybrid genetic-simulated annealing algorithm,H-GASA)。最后以呼和浩特东站及其周围交通网络为例进行实例验证。实验结果表明,与其他算法相比,H-GASA算法在多种时间窗下均能有效降低乘客出行时间和车辆运营成本。此外,H-GASA算法得到的网约车拼车服务问题求解方案更优,收敛曲线更平缓,效率更高,验证了H-GASA在克服遗传算法过快收敛问题上的有效性。展开更多
基金supported by the National Magnetic Confinement Fusion Program of China(No.2008GB109003)
文摘Beryllium (Be) window is a key component of the ITER radial X-ray camera (RXC). The Be window presented in this paper has a mechanical clamping structure, the thickness of the Be foil is 80 μm, and the X-ray threshold of the 80 μm Be foil is 1.24 keV. A honeycomb support is designed and applied to strengthen the Be foil to prevent it from breakage when it is exposed to 1 atm perssure. Based on analysis results, the hole diameter of the support is chosen as 4 mm. A metal seal is used to isolate the vacuum on two sides of the Be window, the hollow metal sealing ring ensures the He leakage rate of the Be window being lower than 6× 10^-1 Pa.m^3.s^-1. Baking (240 ℃, 2 h) and vibration(3.3 Hz, 2 h) tests are carried out and the feasibility of the Be window's sealant in these situations is tested. The Be window has good stability that can save maintenance cost as well as enhancing the safety of the RXC.
文摘目前网约车拼车服务存在响应不及时、乘客舒适度低等现象,亟需对拼车路线及求解算法进行优化。本文首先考虑路网条件及时间窗阈值影响,以网约车运行成本与乘客出行成本最小化为目标,构建基于双向线路的网约车拼车优化模型("one-to-many"online car-hailing carpooling model under multiple constraints)。其次以遗传算法为基础,结合模拟退火温度调控机制,改进适应度评价和接受准则,提出混合遗传-模拟退火算法(hybrid genetic-simulated annealing algorithm,H-GASA)。最后以呼和浩特东站及其周围交通网络为例进行实例验证。实验结果表明,与其他算法相比,H-GASA算法在多种时间窗下均能有效降低乘客出行时间和车辆运营成本。此外,H-GASA算法得到的网约车拼车服务问题求解方案更优,收敛曲线更平缓,效率更高,验证了H-GASA在克服遗传算法过快收敛问题上的有效性。
基金Supported by Jiangsu Natural Science Foundation(BK2011698)Specialized Research Fund for the Doctoral Program of Higher Education of China(20113219120017)+1 种基金China Postdoctoral Science Foundation(20110491424)Jiangsu Planned Projects for Postdoctoral Research Funds(1101081C)