Diglycol diacetate had been obtained with sulfuric acid or toluene - p - sulfonic acid as catalyst in lab.研究了在实验室条件下,以硫酸、对 甲苯 磺酸为催化剂合成二甘醇二醋酸酯的方法.The synthetic principle and the process method diglycol dioleate were discu...
Quality advantage of the alterable thread length scanning system is evident.变长线扫描系统采用的扫描方式和聚焦元件使线束宽度小且恒定,线束功率密度与点扫描焦斑的相当.Three alterable experimental parameters were chosen: liquid pressure, flux and electrostatic voltag...
a silver brooch with ruby insets镶嵌红宝石的银胸针She is wearing a small ruby earring.她戴着一枚红宝石小耳环.The shooting-range is lit from underneath by rows of ruby-red light fittings.射击场被一排排深红色的灯光设备从下面照亮了....a ruby and diamond ring.红宝石钻戒...
天文研究开始向整个电磁波谱范围延拓.Astronomical research began to spread over the whole range of electromagnetic waves.分子转动的实验研究被称为微波波谱学.The experimental study of molecular rotation is called microwave spectroscopy.微波波谱学家已经确定了许多分子的转动常数.M...
一名工人用金属箍箍那保险箱.A worker put metal bands around the safe.外科医生在膝盖骨上套了个金属箍以帮助其愈合。Surgeons placed a metal band around the knee cap to help it knit back together.这桶有两个金属箍箍着.The barrel had two metal hoops round it....