This handout describes standard extraction and washing protocols that can be applied to virtually any crude reaction mixture. Aqueous washings are done to remove water soluble impurities from organic products since normally the compound that you desire will be dissolved in Reference

发现一些薄层分析法更复杂的技巧---剪玻璃TLC板,用火 焰造TLC染色剂点棍,使用TLC染色剂以使点显像。 Discover a few of the more complicatec skills related to thin layer chromatography cutting glass TLC plates, flame-pulling spotters, and using TLC stains to visualize spots

要熟悉流管柱层析法需要适当的练习。此影片将会让从你填充 的适当条件技巧开始、填充及进行管柱层析,甚至用管子做一个微 管柱层析。 It takes considerable practice to master the art of \running a column\. This video will get you started, with tips on picking appropriate conditions, packing and running a column, monitoring separation, and even making a micro-column from a pipet

不要让不精确在实验室阻碍你!此影片介绍正确方法来使用滴 管、滴定管、量瓶和注射器精确测量液体体积。 Don't let inaccuracy hold you back in lab! This video introduces the proper methods for measuring precise volumes of liquid using pipets, burets, volumetric flasks, and syringes

使用旋转挥发仪:旋转挥发仪是你在实验室的好朋友。此影片 中将会确定你建立了一个安全并产生关系。 Using the Rotavap: The rotary evaporator is your friend in the lab. This video will ensure that you build a safe and productive relationship

从固态到气态,然后直接回到固态。此纯化技巧既漂亮又实用 的。找出此影片中为什么用大气压力来升华二茂铁(Ferrocene) From solid to gas, and then straight back to solid. This purification technique is both beautiful and useful. Find out why by watching the atmospheric pressure sublimation of ferrocene in this video

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第一节植物界(在生物分界中的地位) 第二节植物在自然界和人类生活中的作用 第三节植物科学的研究对象和基本任务 第四节植物科学在自然科学和国民经济发展中的意义

一、均衡价格的变动 二、均衡价格是由供求相对水平决定的 三、供求是由许多因素决定的 四、当这些因素发生变化时,就会引起供求发生变化,进而导致均衡价格和(或)数量发生变动

第一章绪论 教学要求:了解测量学的研究对象及其在工 程建设中的作用,掌握测量学的基本概念、 基本知识、测量工作的基本原则和测图原 理。 本章重点:基本概念(如铅垂线、大地水准 面、绝对高程、相对高程等),确定地面 点位的方法,测量工作的基本原则和测图 原理