标签:
杂谈 |
Academic Paper Analysis
认真阅读和研究与自己专业密切相关的一篇SCI, EI或其它重要的英语论文,
长度5-10页为宜。用Word写出研读收获。完成后贴在自己的Blog上,并且附上原文的第一页照片。
然后写出(或列出)该文章的:
1
题目:以Li-Al水滑石为催化剂,由大豆油制备生物柴油
摘要:简明扼要地总结了Li-Al水滑石作为大豆油制备生物柴油的催化剂的优点:活性高,反应时间短,此外还研究了醇/油摩尔比、催化剂用量等因素。
正文主要包括以下部分:介绍(Introduction)、Experimental(实验)、Results and Discussion(实验与讨论)、Conclusions(结论),最后是致谢和参考文献。章在结构上的安排清晰明了,大标题下设置了多个小标题,读者阅读起来很方便,能很好地将作者所做的工作展示给读者。
2每一段落的展开方法;
I. INTRODUCTION
介绍了本研究的背景、意义和现状。
由于化石能源的减少,环境污染的加深以及国家战略安全的考虑,必须加大对生物质能源的研究、开发和利用。目前生物柴油的制备主要通过甘油三酯与醇(主要是甲醇)的转酯化反应来完成,大豆油是一个很好的原料。在催化反应中,催化剂是一个非常重要的因素。文章分别介绍了均相催化剂和非均相催化剂的优缺点,总结了前人在这方面所做的工作,最后选择了Li-Al水滑石的优势之处并以其作为本实验的催化剂。
II. EXPERIMENTAL
实验部分包含三个内容:催化剂的制备、表征手段和大豆油的转酯化反应。
催化剂的制备
制备了Li-Al水滑石和Mg-Al水滑石,并以后者作为对照,通过对照显示出Li-Al水滑石的比较优势,这是实验思想的一个亮点。
表征手段
采用BET、XRD、TGA、Hammett等方法来表征所制得的催化剂。
转酯化反应
依靠H-NMR手段来计算酯化反应的转化率。
III. RESULTS AND DISCUSSION
自然科学类的论文,多需要许多的图表、数据来佐证撰写的论文,本文亦不例外。结果与讨论部分是论文中最核心最重要的一块,作者也花了很多的笔墨来叙述。该部分包含如下几个方面:催化剂的表征、两种催化剂在转酯化反应中的比较、焙烧温度的影响、反应条件的影响以及催化剂的失活。深究发现,这一部分的展开上也是有深层的逻辑的。先是讲催化剂,只有制备了催化剂才能进行下一步的反应;接着就是比较两种催化剂在反应中的性能表现,通过比较发现不同,进而去分析导致这些不同的原因,这样就溯本求源,发现焙烧温度这样影响因素,原来是焙烧后比表面积和孔径发生了变化以及形成了新的晶相;选择性能优良的Li-Al水滑石后,接着就要探索工艺条件,诸如醇油摩尔比、催化剂用量、反应时间等因素的影响;最后,出于工业上应用和推广的考虑,必须考查催化剂的循环使用次数,亦即其失活情况。
因此,本文在结构安排上井井有序、环环相扣,安排得不突兀,很便于读者的阅读和理解。
IV. CONCLUSIONS
结论是对先前工作和结果的总结,通过实验发现,焙烧后的Li-Al水滑石是一个很好的催化剂用来催化大豆油制备生物柴油:其活性高,反应所需时间少,其失活实验表明即使经过多次循环使用,其仍然能保持很高的活性。
最后是致谢和参考文献的列表。
3 写作特点和风格
这篇论文如许多化学类论文一样,以客观事实(数据、图表和文献)来说明问题,全文保持客观冷静的风格,多采用被动语态,避免了主观的个人感情色彩。措辞上多将动词名词化,显得就非常的专业和高明。
此外,许多的专有名词则采用了缩写,领域内的读者一看就能明白,显得简约不啰嗦。文章在段落的安排上也很有结构,大标题下各个小标题,基本按照总分的方式展开,层次清晰明了。
多用图和表来表述问题,更有说服力,很一目了然,避免了太多叙述性的语言,而且便于读者接受。
4 所有重要句型
文中有许多句型的运用很独到,很少的词表述了很丰富的信息,列举如下:
Base catalysis is preferred to the use of acid catalysts such as sulfuric or sulfonic acids, given the corrosivity and lower activity of the latter.
In order to circumvent these problems, the use of heterogeneous catalysts has been explored.
Upon heating, LDHs decompose to mixed oxides with loss of water and CO2 (for the carbonateform of the LDH).
This suggests that either lithium incorporation in the gibbsite-type layers is incomplete, or that a separate, X-ray amorphous aluminum phase is present, such as pure gibbsite or boehmite.
Upon calcinations at 450 oC , the LDHs decomposed via decarboxylation and dehydroxylation to form mixed oxides, with an accompanying increase in surface area.
Methanol was used as the solvent so that the measured surface basicity would provide a reasonable reflection of that expected under reaction conditions.
Transesterification experiments were performed at reflux temperature, initially using a fixed methanol to soybean oil mole ratio of 15:1 and a catalyst charge of 1wt% (based on the quantity of soybean oil used).
Given the similar results of the Hammett indicator measurements for the two materials, these results suggest the involvement of Lewis basic sites in transesterification catalyzed by the calcined Li–Al LDH.
As shown in table 4, the calcination temperature used has a significant impact on the activity of the Li–Al LDH catalyst in soybean oil transesterification.
In the absence of catalyst, no soybean oil conversion to methyl esters was observed.
Given that trigylceride transesterification consists of a sequence of three reversible reactions in which the triglyceride is successively transformed into diglyceride, monoglyceride and finally glycerol and fatty acid methyl esters, it follows that the mole ratio of methanol to soybean oil influences the conversion to methyl esters.
The maximum rate under these conditions, was obtained at a mole ratio of approximately 20:1, beyond which additional methanol had minimal effect.
According to these results, after one recycle the catalyst appears to have decreased in activity, however, the yield of esters measured for the catalyst subjected to two recycles is only slightly lower than that obtained with fresh catalyst; in fact, the difference is on the same order of magnitude as the observed experimental variability.
5 所有重要单词和对应中文
corrosivity 腐蚀性
circumvent 绕开
lamellar 层状的
tunable basicity 可调的碱性
dropwise 一滴一滴的
outgassed 除气
whereupon 然后
diffractograms 衍射图样
stoichiometry
amorphous 无定形的
analogue
matrix
commences 开始
overlaps 覆盖
phase transition 相转变
conversion 转化,转变
progressive increase 递增
successively 一个接一个地
conducted 执行,实施
corresponding to 符合,一致
associated with 与…有关,有联系
Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) 电感耦合等离子体发射
6
主谓搭配: In order to produce a fuel that is suitable for use in diesel engines, the triglycerides are converted to the respective alkyl esters and glycerol by transesterification with short chain alcohols, typically methanol.
动宾搭配: This approach eliminates the need for an aqueous quench and largely eliminates the formation of metal salts, thereby simplifying downstream separation steps; consequently, biodiesel production can be more readily performed as a continuous process.
形容词与名词的搭配: particular interest; effective catalysts; progressive increase ;
副词与动词的搭配: typically composed of; readily performed; generally found; subsequently isolated; was added dropwise
介词与名词的搭配: Upon heating; has a significant impact on the activity; beyond which
短语动词: is preferred to; prior to; contrasts with; consistent with.
7 冠词的用法,时态的用法和其它;
定冠词 the的用法:(1)表示特指;(2)
例如:the fatty acid esters;the mineral hydrotalcite; The Li–Al catalyst;The strength of the basic sites
不定冠词a(an)的用法: 其基本的用法就是表示“一”这个概念,另外还有(1)用于表示某一类人或物;(2)指某人或某物但不具体说何事何人何物;(3)用于某些固定的词组。
例如:a number of;in a vacuum oven;a Micromeritics Tri-Star system
所用到的时态主要有过去时、现在(过去)完成时等。
8)参考引用他人作品的方式.
举两个作者引用的例子:
在文中以[*]标出位置(*为数字),参考文献中再详细列出来。
研读收获
阅读完此论文以后,了解很多科技论文的写作手法和风格,对自己以后的论文写作有很大的帮助。比如,语言宜多采用被动语态,避免主观的个人感情色彩,使得所撰写的论文有说服力,分析客观有依据。因为科技论文不是散文,小说,它需要大量的数据材料来佐证,所以写作时要安排的得有条理、有层次,万不能写作时天马行空,想到哪写到哪。另外,科技论文在可以用缩写的地方宜用缩写,这样就使得文章简洁明了,避免啰嗦和累赘。时态上的使用也得格外注意,不同的时态其含义是不同的,正确使用可以很好的避免歧义。
最后,为了利于以后自己撰写论文,应多看该领域的相关文献,并将常用的句型和词语总结下来,这样在自己写得时候就可以套用这些结构。


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