concave GRE

A concave mirror would project a real inverted image of the silverpoint onto the panel, which van Eyck would trace.

面镜把颠倒的实像投射到木板上，于是范艾克便可以在板子上描画。

Dicyano 9,10 dihydro 9,10 ethenoanthracene(4) was synthesized by addition reation of acetylenedinitrile and anthracene. Concave tetrazaporphyrin has been obtained from the four molecules of 4.

乙炔二环加成应合成了11,12-二-9,10-二氢-9,10-亚乙烯基(4),4分子4自身加成聚合制备了一种全新型四氮杂口卜啉结构化合物。

As a practical example, an astigmation corrected scanning flat holographio concave grating (SFHCG) is designed and some results of the numerical and optical experiments are given.

给出一消像散SFHCG的设计实例和用这块光栅所做的实验结果。