[文书] PS求拍活动结束。。。谢谢各位··· [复制链接]

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发表于 2013-12-27 18:44:01 |只看该作者

语法、用词什么的我就不说了，还是要改
My career goal is to become a qualified organic chemist, who will both advance world’s research on organic synthesis by conducting laboratory studies and help pharmaceutical factory by design facile and efficient synthetic routes. I believe the most ideal way to accomplish this goal is to pursue a Doctor’s degree in organic chemistry, where I will learn scientific interpretations of how these atoms are tied together to form functional molecules and acquire advanced experiment skills.

I am mostly interested in developing novel and environment friendly synthetic method, which stems from the project I participated during college. My task is to explore the optimal conditions of synthesis of Xanthen-9-one using Fe (III) as catalysis. The method I used was controlling variates. For example: I would like to start the exploration with a fixed solvent like ethanol, a fixed amount of catalyst, a fixed ratio of the reactants and a varying temperature. Although at that time our college had no instrument (like LC) to tell me the final yield做合成的人不会用LC去算产率的…… 基本都是报的分离产率，用GC什么的报收率都要标注, which means I have to isolate the products by myself again and again using the silicon column做有机的人要是不会过柱子就挂透了。你用PE/EA=500/1的极性过过柱子分离在极性20/1的展开剂下挨在一起的两个东西吗？你做的那种化合物应该是处在很好分离的极性范围内的……这个是必备技能，不是需要克服的困难……然后过柱子是column chromatography，不是硅胶柱直译……, I never got tied about the project. On the contrary, I developed the skills of purifying the products by silicon column and had a better understanding of how to conduct research on my own.= =It's far from conduct research on my own...

Despite这个句子结构有问题 the hardworking in the laboratory gave me a good foundation in organic synthesis research, I always believe a deep understanding of the relationship between optimal conditions and final yields can make my research more efficient. Therefore, I become a graduate student majored in physical organic chemistry. 最优条件是怎么和物理有机直接联系上的啊……

My project is to develop asymmetric NADH organic hydride compounds as chiral reduction reagents.下文都没有看到一个不对称的NADH化合物以及你的反应的ee值…… As we all known我觉得你这里写得太多了, hydride transfer involves three mechanisms: one step hydride transfer, electron-proton-electron transfer and proton coupled electron- electron transfer. Different mechanism will lead to different products. For example, if the reduction is hydride transfer, then the hydride will add to the reaction site directly. If the electron transfer first, then the radical may be resonated to other site of the molecule skeleton or the product would become the dimmer.

Then, I use both thermodynamic and kinetic method to investigate the mechanism of hydride transfer. First, I measure the total energy released by the hydride transfer by using the Isothermal Titration Calorimeter. Then I detect the electric potential by E小写lectrochemical apparatus. According to Hess’s Law, I calculate the energy of each possible step and determine the mechanism. To further verify my analysis, I use the kinetic method, specifically, detecting the reaction rate constant in various temperature by Stop-Flow, calculating the activation energy according to Arrhenius equation. I also deuterate the hydride of my compounds for two reasons: 1) I can use the kinetic isotope effect to determine whether the reaction is hydride transfer. 2) If the mechanism is hydride transfer directly, then the acceptor’s reaction site should be deuterium which has no absorb peak in H1NMR.实验结果呢。。而且你研究的是NADH还原吗？这里太模糊了

Three years study in the graduate school offers me a solid foundation in organic chemistry theory as well as experiment skills, which also ignited my desire to put what I leant into practice, namely, into developing novel synthetic method and medicine discovery.

I believe University of XX is the best place for me to further my advanced research, I am especially attracted to the research conducted at XX, namely the Organic synthesis and drug discovery research by Professors David, Daniel. I am confident that joining such research group consisted of expert faculty will best build upon my research experience and extend my research abilities.

"错误的世界观比糟糕的化学更令人失望十倍"

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[文书] PS求拍活动结束。。。谢谢各位··· [复制链接]

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