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无链条电动自行车

无链条电动自行车,整体外形时尚,没有了链条,外观变得与普通自行车或电动车有些不同,如图所示.无链条电动自行车被称为“没有链条的混合动力电动自行车”.它结合了电子动力和人体动力,此车既可以通过给锂电池充电获得能量;也可以通过骑行者踩脚踏板获得能量.骑行者踩脚踏板的动能,可通过车上的发电机转化为电能,存储在自行车框架中的锂电池内,之后通过电动机驱动后轮转化成动能,以此驱动自行车前进.因此使骑行者骑得更省力,同时也能减少对环境的污染.

图中所示这款无链条电动自行车,其锂电池容量为10Ah、电压为36V.

与链条车相比,这种新型自行车具备许多优点.比如:省力、耐用、安全、灵便、干净卫生、结构简单、修理方便,骑行12000km也无须大修.因此,无链条电动自行车是城市中一种理想的交通工具.

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    Nervous suspects locked up in Britain's newest police station may feel relieved by a pleasant yellow color on the door . If they are close to confessing(供认)a crime , the blue on the wall might tip the balance .

    Gwent Police have abandoned colors such as greys and browns of the 20th-century police cell(牢房)and have used color psychology to decorate them .

    Ystrad Mynach station , which recently opened at a cost of £5 million has four cells with glass doors for prisoners who suffer from claustrophobia(幽闭恐怖症). Designers have painted the frames yellow , which researchers say is a calming color . Other cells contain a royal blue line because psychologists believe that the color is likely to encourage truthfulness .

    The station has 31 cells , including 12 with a “live scan” system for drunken or disturbed prisoners , which detects the rise and fall of their chest . An alarm alerts officers if a prisoner's breathing stops and carries on ringing until the door is opened .

    Designers and psychologists have worked for years on color . Blue is said to suggest trust , efficiency , duty , logic , coolness , thinking and calm . It also suggests coldness and unfriendliness . It is thought that strong blues will stimulate clear thought and lighter , soft colors will calm the mind and aid concentration .

    Yellow is linked with confidence , self-respect and friendliness get the color wrong and it could cause fear , depression and anxiety , but the right yellow can lift spirits and self-respect .

    Ingrid Collins , a psychologist who specializes in the effects of color , said that color was an “ energy force ” . She said : “ Blue does enhance communication but I am not sure it would enhance truthful communication . ”

    Yellow , she said , affected the mind . Red , on the other hand , should never be considered because it could increase aggression . Mrs. Collins praised the designers for using colors in the cells . Gwent is not the first British force to experiment with color to calm down or persuade prisoners to co-operate , In the 1990s Strathclyde Police used pink in cells based on research carried out by the US Navy .