立竿见影的意思：
词面指在阳光下竖起竹竿，立刻就看到了竹竿的影子。词意指喻行事能马上看到效果或付出能马上得到收获。
英文解释
set up a pole and see its shadow -- to get instant results;A shadow is cast as soon as a pole is raised.;can get good results temporarily;get quick results ;
【出自】：汉·魏伯阳《参同契》卷下：“立竿见影，呼谷传响。”
【示例】：你说你莲花化身，清净无为，其如五行变化，～。
◎明·许仲琳《封神演义》第七十八回
【语法】：连动式;作谓语、定语、宾语;比喻事物见效快
【近义词】马到成功、立见成效、卓有成效、吹糠见米
【反义词】旷日持久、劳而无功
【物理原理】光在同一种均匀介质中沿直线传播，光在照射不到的区域形成影子。光速是自然界中速度最快的速度。
【歇后语】 太阳底下竖竹子——晴天白日
【其他解释】词义也可理解为此处有光照或投影版与投影颜色不一致。
中英例句
本次东京年会可能没有达到立竿见影的效果。
The tokyo meetings may not have had immediate impact.
这样做能够给中国正在放缓的经济带来的立竿见影的提振效果。
To do so would provide an immediate boost to the weakening economy.
周二，facebook协调各方捍卫其广告业务的种种努力并未对投资者产生立竿见影的效果。
On tuesday, facebook's coordinated efforts to defend its ad business didn't have much of an immediate effect on investors.
他说，在该项目开始后，昂贵的抗逆转录专利药物对其产生了立竿见影的影响。
He says the high cost of patented antiretroviral drugs had an immediate influence on the program after it began.