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Cake day: 2023年7月24日

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  • While technically a high speed ‘regional’ metro(like the ones China has been building) does have a top speed of 160km/h, it is more like regional rail than a ‘lowest tier’ urban transit. Most metro systems have a top speed of 80km/h due to station spacing and physics (motor gear ratios tuned for accelaration).

    That or you are talking about the Keisei Skyliner, which is an Airport Express service.






  • royal_starfish@lemmy.worldtoMemes@lemmy.mlEVs
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    1 年前

    You can use liquified hydrogen which need to be chilled and insulated, and will evaporate away in a short time if not properly sealed

    Or you use compressed hydrogen which means you are basically carrying an IED that weighs several hundred kilograms with the amount of pressure inside the gas tank

    And hydrogen combustion is as others have said, inefficient.

    Another issue is that you also need to use basically pure oxygen if you want to use a hydrogen fuel cell, otherwise the catalyst inside the cell would get poisoned

    And well, there is a car that did all that, the Toyota Mirai, but that also pretty much ended in commercial failure, due to lack of hydrogen filling infrastructure and a whole load of other reasons.