本发明涉及一种制备Ｌ－肉碱的方法，其包括如下步骤；步骤１（如图）步骤２（如图）其中，步骤１采用不对称催化氢化反应，步骤２采用相转移反应、碱性催化剂和低温反应条件，从而大大提高了产物Ｌ－肉碱的收率，总收率高达７０％
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The present invention disclosed a foot massage apparatus which comprises: a housing; a pair of replaceable footprint plates with holes arranged according to a particular foot massage pattern, which are placed on an upper plate of the housing; protrusions protruding from the holes of each replaceable.....
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The invention relates to an FRP (fiber reinforce plastic) tube-concrete-steel tube combined tube tower comprising an inner steel tube, an FRP outer tube and a concrete layer, wherein the inner steel tube is formed by connecting a plurality of steel tube segments, the FRP outer tube is formed by conn.....
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