美國留學生英語本科課程dissertation范文參考下載 Researches on a chemistry-related article

摘要：本文主要是關于新的生化信息科學日報“。阿肯色大學的研究人員和他的同事們發現，這是一個新的研究結果。他們已經發現了一個古老的厭氧微生物的重要組成部分，可以作為一個傳感器來檢測潛在的致命性的氧氣。更重要的是，這將有助于研究人員了解更多有關這些組件的功能，稱為鐵 - 硫簇，其中發生在所有生物細胞中的不同部分。通過這篇文章，我們可以學到一些東西約甲烷#p#分頁標題#e#氣體，在化學領域的一個非常重要的化工原料，但在我們的日常生活中，并知道如何產生甲烷的產甲烷菌，我們會取得更大的進步，在能源利用，幫助我們的人類要解決什么問題。


Abstract: This essay is mainly about new biochemistry information on Science Daily. It is a newly research result found by a University of Arkansas researcher and his colleagues. They had found a key component in an ancient anaerobic microorganism which may serve as a sensor to detect potentially fatal oxygen. What’s more, this will help researchers learn more http://www.400190.com/thesis_sample/ about the function of these components, called iron-sulfur clusters, which occur in different parts of cells in all living creatures. Through this essay, we can learn something about methane gas, a very important chemical material in the field of chemistry, yet in our daily life and by knowing how the methanogens to produce methane, we would make greater progress in energy utilize and help us human beings to solve much problems.


Key words: chemistry; methane; iron-sulfur clusters; energy

1. Introduction
Chemistry is the science which researches in material composition, structure, nature, and law of  variation. The world is made up of material, and chemistry is one of the ways that human beings to understand and transform the world. It is a vibrant discipline with a long history and its achievement is an important symbol of social civilization. The discipline of chemistry can be divided into many small branches, of which biochemistry is an important one. Biochemistry is a discipline which uses chemical principles and methods to study the phenomenon of life. Through researching in the living organisms’ chemical composition, metabolism, nutrition, enzyme function, genetic information transfer, biofilms, cell structure and molecular diseases and so on to clarify the phenomenon of life.#p#分頁標題#e#

2. Main content of the new
The article  from the website above introduced a kind of microorganisms named “iron-sulfur clusters” to us, it can produce an important chemical materials which known as methane. The iron-sulfur clusters are important because they exist in most life forms, including humans. In fact, people could not survive without their iron-sulfur clusters. Daniel Lessner and his colleagues found that in some methanogens and other single-celled organisms, the protein RNA polymerase contains iron-sulfur clusters. This will give us a better understanding of the role of iron-sulfur clusters in this simple organism and will also help scientists understand and perhaps control production pathways in these microorganisms to produce methane gas as a biofuel.

3. Discusses on the new

3.1 The nature of methane
In fact, this news gives us important information that scientists can use this study result to produce methane by culturing this iron-sulfur clusters. This method will help us to solve the increasingly serious energy problems. Methane is widely distributed in nature, it is the main component of natural gas, biogas, oil, gas and coal mine tunnel gas. It can be used as fuel and raw materials of manufacture of hydrogen, carbon black, carbon monoxide, acetylene, hydrogen cyanide and formaldehyde and other substances. The chemical symbol of methane is CH?. Methane is a colorless, odorless, flammable and non-toxic gas. It has a weight ratio of 0.54 compared with air, and its solubility is very small. At 20℃, 0.1 kPa, 100-unit volume of water can only dissolve 3-unit volume of methane. It will produce a bright light blue flame during combustion.

The chemical structure of methane belongs to molecular crystal and its molecular structure is as following: tetrahedral non-polar molecule, a C is in the center of the tetrahedron in the form of sp3 hybridized, while 4 H are in the four vertices of the regular tetrahedron. Under the adiabatic condition, heating methane to 1,000 degrees, it will decompose to produce carbon black and hydrogen.

3.2 Using methanogens to produce methane
Methanogenic bacteria are prokaryotes. They are strictly obligate anaerobic, growing especially slowly and are very difficult to separate when culturing them. Methanogens can not survive with oxygen existing, and therefore they can only be found in an environment completely lack of oxygen. Methanogenesis and fermentation can only occur in the case when carbon compounds are as an electron acceptor. Methane production has great usage for human and organic waste can be converted into useful methane. Methane is a fuel gas of high quality, it is also an important raw material for manufacture of synthesis gas and chemical products. The natural gas we use is mainly component of methane, and it is a non-renewable energy resources, with constant human exploitation and consumption, its reserves is very small and has been near the exhausted edge. The found of methanogens will help us to deal with energy depletion, providing us with a broader source of energy.#p#分頁標題#e#

4. Conclusion
According to the news about some chemical knowledge, we know a new kind of bacteria which can produce methane, understanding the relevant mechanism how these bacteria to produce methane. This found will help our scientific research and play a significant role in promoting function and provides new ideas and approaches for the unresolved energy issues.

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