求一篇英文的化学实验报告范文（
Chemistry Lab sample
(This is one of my Chemistry 11 lab assignment。)
Title:
Cooling and Heating Curves of a Pure Substance
Objectives:
to investigate the cooling process for liquid paradichlorobenzene
to investigate the heating process for solid paradichlorobenzene
Materials:
Apparatus: rin stand and ring support buret clamp
bunsen burner; wire gauze with ceramic centre;
test tube(18mm*150mm); beaker(400ml); 2
thermometers; lab apron; safety goggles.
Reagent: paradichlorobenzene
Procedure:
Data and observations:
So generally, its the data you record throughout the lab. Data table should be customized for each lab.
Conclusion:
Questions and follow-up questions:
Answer any question assigned at the back of the lab
After all, this is only a high school lab example. If you are looking for a university chem lab template, i guess it would be more spesific in details。 well, generally, it goes like that. you can write your own one as long as you think you make clear of what you do. Have fun with it.
求一份英文实习report(300字左右)
这是范文这学期是我任教的第一学期，我担任初一级七班，八班的英语教学。
由于教学经验颇浅。因此，我对教学工作不敢怠慢，认真学习，深入研究教法，虚心向前辈学习。
经过一个学期的努力，获取了很多宝贵的教学经验。以下是我在本学期的教学情况。
因此，了解和分析学生情况，有针对地教对教学成功与否至关重要。最初接触教学的时候，我还不懂得了解学生对教学的重要性，只是专心研究书本，教材，想方设法令课堂生动，学生易接受。
但一开始我就碰了钉子。在讲授第一课的时候，我按照自己的教学设计，上了一堂自认为明白
易懂而又不死板的课，认为教学效果如期理想，怎知小测出来才知道不如人意。
后来听同学们反应，才知道我讲的口语大部分同学听不懂，而教学的部分内容同学们以前从来
未接触过。从而可知，我在上课前根本没有了解清楚学生的实际情况：一方面，农村的学生英
语听，说的能力相对较弱，授课采用较深的全英教学，同学们还不能适应。
另一方面，七班的同学比较活跃，上课气氛积极，但中等生占较大多数，尖子生相对较少。因此，讲得太深，没有照顾到整体，而八班的同学比较沉静，学习欠积极性，虽然优良生比例大，但中下层面而也广，我备课时也没有注意到这点，因此教学效果不如理想。
从此可以看出，了解及分析学生实际情况，实事求是，具体问题具体分析，做到因材施教，对
授课效果有直接影响。这就是教育学中提到的“备教法的同时要备学生”。
这一理论在我的教学实践中得到了验证。教学中，备课是一个必不可少，十分重要的环节，备
学生，又要备教法。
备课不充分或者备得不好，会严重影响课堂气氛和积极性，曾有一位前辈对我说：“备课备不好，倒不如不上课，否则就是白费心机。”我明白到备课的重要性，因此，每天我都花费大量
的时间在备课之上，认认真真钻研教材和教法，不满意就不收工。
虽然辛苦，但事实证明是值得的。一堂准备充分的课，会令学生和老师都获益不浅。
例如我在教授Unit 3 . Lesson 9 的时候，这课的主题是“如何询问和回答时间”，教学难度比较大。如果照本宣科地讲授，学生会感到困难和沉闷。
为了上好这堂课，我认真研究了课文，找出了重点，难点，准备有针对性地讲。为了令教学生动，不沉闷，我还为此准备了大量的教具，授课时就胸有成竹了。
当讲到“half”的时候，我拿出准备好的圆卡纸，把它剪成一半，告诉学生这是圆的一半，也就
是half。讲到”quarter”时，又把半圆剪成一半，那么剩下来的就是圆的四分之一，也就
是”quarter”了。
这样学生就形象地明白了这两个单词。而讲到如何表达时间时，我用了一个用红卡纸做的大钟，同学们一开始就被它吸引住了，显得颇有积极性。
特别是对英语这门学生不甚熟悉并感到困难的外语来说至关重要。备课充分，能调动学生的积
极性，上课效果就好。
但同时又要有驾驭课堂的能力，因为学生在课堂上的一举一动都会直接影响课堂教学。因此上
课一定要设法令学生投入，不让其分心，这就很讲究方法了。
上课内容丰富，现实。教态自然，讲课生动，难易适中照顾全部，就自然能够吸引住学生。
所以，老师每天都要有充足的精神，让学生感受到一种自然气氛。这样，授课就事半功倍。
回看自己的授课，我感到有点愧疚，因为有时我并不能很好地做到这点。当学生在课堂上无心
向学，违反纪律时，我的情绪就受到影响，并且把这带到教学中，让原本正常的讲课受到冲击，发挥不到应有的水平，以致影响教学效果。
我以后必须努力克服，研究方法，采取有利方法解决当中困难。英语是一门外语，对学生而言，既生疏又困难，在这样一种大环境之下，要教好英语，就要让学生喜爱英语，让他们对英语产
生兴趣。
否则学生对这门学科产生畏难情绪，不原学，也无法学下去。为此，我采取了一些方法，就是
帮助班上的同学改英文名，尽量多讲一些关于英美国家的文化，生活故事，近来更帮部分同学
交上了”penfriend in America”，让他们更了解英语，更喜欢学习英语。
因为只有英语水平提高，他们才能达到交异国笔友的目的，同时也可以提高同学们的英语写作
能力，对成绩优秀的同学很有好处。因为英语的特殊情况，学生在不断学习中，会出现好差分
化现象，差生面扩大，会严重影响班内的学习风气。
因此，绝对不能忽视。为此，我制定了具体的计划和目标。
对这部分同学进行有计划的辅导。例如在七班，我把这批同学分为三个组。
第一组是有能力提高，但平时懒动脑筋不学的同学，对这些同学，我采取集体辅导，给他们分
配固定任务，不让他们有偷懒的机会，让他们发挥应有水平；第二组是肯学，但由于能力不强的同学。对这部分同学要适当引导，耐心教导，慢慢提高他们的成绩，不能操之过急，且要多
鼓励。
只要他们肯努力，成绩有。
英语口语实训报告
1 实习时间：2012年1月2日-1月6日
2 实习地点：李子园校区一栋教学楼108
3 实习单位：邵阳学院
4 实习过程概述在2012年1月2日-6日，我们进行了为期五天的《英语口语》课
程实习。
在老师的悉心指导下，我们的实习井然有序的展开。语音室口语学习的一个重要组成部分，标
准的语音能让别人更确切地理解你想表达的意思，也可以说学好语音是学好口语的基础。
因此，我们实习的第一步从语音开始，然后是语音语调，最后是实际的练习与交流。5 主要实
习岗位和实习内容怀着期待的心情，我们开始了口语实习的第一天。
刚上课老师就要我们每个同学读一小段文章。借此机会来了解一下我们的基础。
我有点紧张，生怕自己读不好，出洋相。在我读的过程中，我能很明显的觉得自己有点喘不上气，而且语句的连接也不是很顺畅，经常有回读的现象，一碰上不认识的单词也会有点读不上来。
老师也给我指出了一些问题。虽然说口语说的不怎么好，但至少知道自己的不足之处在哪里，
希望以后对症下药，把口语说的更好。
经过昨天的学习，意识到自己在很大程度上需要提高。班上有些同学的口语很好，课文读起来
也很顺畅，流利，于是我就向他们请教了一下方法。
他们也给我提供了一些经验，让我借鉴。比如：有些单词要连读，如：I have a book.经常我们
会把“have a ”连读，轻读。
此外，有时碰上长句，要注意分意群，不要一口气读下去。同时有些词是需要重读的，有时在
交流的时候，别人不可能仔细的去听懂你说的每一个单词，那些重要的单词（如动词）就要重读，让别人能轻易地抓住说话的主题。
课堂上老师建议我们先进行简单的交流，询问一些在日常生活中经常出现的交际用语。我们的
口语实习也进入了一个新的阶段。
语音语调也是口语的一个重要组成部分，实习的第三天我们主要学习了语音语调这个板块。在
日常生活的交际中，同一句话用不同的语调说出来会表达u一样的含义。
简单的举个例子，如“Yes”，读“Yes!”(meaning “of course it is so” )，读“Yes?”(meaning “Is it really so？” )。由此可见，语音语调是及其重要的。
所以我找了一些课文的录音，跟着读，仔细的模仿他的语音和语调，自己觉得又进步了一小步。为期五天的实习已经过去了3天，仅剩和最后的两天。
练口语最重要的是“练”，前面的相关学习是为了更好地学习口语，如果不说出口，那也就不是
口语了。所以还是要将口语还原到生活中去。
在每个礼拜的星期四，外语驿站都会举办“English corner”活动，来自各个不同的年级，不同系
别的同学聚在一起用英语交流。怀揣着某种期望，我也去了，希望自己几天来的学习能得到实践。
在“English corner”我和几个来自中文系和生化系的同学进行了交谈。我们聊了各自的学习和最
近的生活状态以及将来的就业倾向。
在那刻我觉得用英语来交谈是件多么令人高兴地事，这也许就是语言的魅力所在。当然，通过
参加这次活动我也了解到了自己的不足：词汇太贫乏了。
有时一些事情找不合适的单词去表达，所以记好单词也是学好口语的一个关键。这是实习的最
后一天，意味着我们是实习课程也该画上圆满的句号了。
为了检测我们的学习成果，老师在之前给我们布置了一个任务：每个同学做一个简短的“Duty report”.我们被要求站在讲台上用英语给大家介绍一些东西，具体内容自己选择。我准备的是
日本的樱花节“Blossoms Festival”我觉得这不仅仅是在考察我们的口头表达能力，更是对我们
应变能力的检测。
因为有时你会由于紧张忘词，或者被别人提问。当我面对同学自由提问的时候，还是有点不能
迅速反应过来，给他们一个很好的回答。
所以敏捷的思维也是我以后要多加注意和提高的地方。6 实习收获和重要心得体会刚开始实习
的时候很紧张，生怕自己会出错。
可是不出错就很难进步。通过课堂上老师的指导以及课后与同学的交流，我认识到自己在口语
方面存在的诸多不足，并且在老师和同学的帮助下，积极地练习，尽自己最大地努力做到最好。
虽然实习的日子只有短短的几天，一下就过去了，但我收获了很多。从中我体会到将知识转化
为能力的重要性以及人际交往中的一些必备技巧。
同时通过交流我还感受到了中西方文化的差异，很是受益。7 存在不足和建议通过这次实习，
我在口语方面有了些提高，但仍然存在一些没有做好的地方。
学习最重要的是持之以恒，很多时候我会觉得学习很无聊，想半途而废，所以我需要坚定自己
学习的目标，静下心，切忌浮躁，坚定不移的付出努力。8 其他一方面，希望学校多开展专业
针对性较强的实习课程，更好地提高我们的专业技能。
另一方面我们与外界的交流还是不够，希望能有更多的机会走出学校，真正的走进社会去好好
地锻炼自己。最后就是我发现我们大家对以后的就业和专业发展都比较困惑，不明确自己毕业
以后该怎么去选择就业。
是就业还是考研？我们需要更多的指导。
求一篇英语作文
Boys and girls
1st, arrives at the experiment building punctually, does not permit to be late, absence.
2, in the experiment process, does earnestly according to the teacher guide.when 3, experiment maintains peaceful, does not permit to clamor loudly.
4, safety-conscious, only if teacher permits, does not permit to touch the laboratory the goods equipment.
5, the experiment ended, put away the equipment, washed the hands with the soap, then the order left.
英语作文实验报告
Experimental Report
Experimental purposes: 1. Observed when the temperature of boiling water; 2 observed the phenomenon of water boiling in the process of
Experimental equipment: beaker. Water. Thermometer. Kerosene lamp. Match Experimental steps: first in the beaker have added about 100 grams of water, and then the thermometer into the water, the beaker with the alcohol lamp in the water heating,
Observe the thermometer shows the final number of changes and the water situation.
The experimental results: When the temperature reaches 100 degrees, water with bubbles generated
Experimental results: water began to boil at 100 degrees; water in the boiling bubbles generated when.
Ruby Tan Partner: Kathryn Zhu 04/19/12 LAB#24SL:Musical Intervals Objective: To determine the frequency ratios for common musical intervals. Procedure: Come into the lab, open DataStudio, switch on the interface, select Create Experiment, then Sound Creator. Change simultaneous tones to 2. Then put on the headphone to listen the voice, changing the wave of a sound to a longer wave(lower tones). Hum the indicated for a specified interval and find the pitch for the 2nd note. Do it for 5 times with 5 different songs. Ruby Tan Partner: Kathryn Zhu 09/29/11 LAB#24SL:Musical Intervals Conclusion In this lab, we know the wave of the songs concern with the tones of it. Shorter period waves have a lower tones. Amplitude cause the loudness of the songs. This lab is good for us to analyze the notes of all the songs.
英语作文,实验报告[5篇材料] 第一篇：英语作文,实验报告 请根据下列内容，写一篇短文，说明整个实验的内容。 实验目的：不打烂鸡蛋取走蛋壳 实验器材：一个玻璃杯，一个小锅，水，一个鸡蛋，醋(vinegar)约250毫升 实验步骤：1.把鸡蛋放在锅中煮十五分钟左右； 2.把煮熟的鸡蛋放到玻璃杯中； 3.往玻璃杯中倒醋，醋要漫过鸡蛋； 4.让鸡蛋仔醋中浸泡24小时。 实验结果：24小时后，鸡蛋壳完全消失。 实验结论：醋中的酸性物质(acid)与蛋壳中的碳酸钙(calcium carbonate)反应生成二氧化碳(carbon dioxide)，蛋壳(shell)消失。 注意：词数：100—120。 写作指导：文章体裁是_______,因此时态可以是_______,全文可以这样分段： 内容及要点信息常用句型及词汇： 实验目的：the aim of the experiment is to…;in order to find out…;we carry out an experiment to…;with the purpose of…;in the hope of 实验器材：you need…;the following things are neededwill be used 实验步骤或方法：cookboil,fill…in,weigh,wait,place,react反应,form；first,first of all,next,second,after that,finally, in the end,at last, for 15minutes,24hours later… 实验结论：from this we can conclude…we can learn from the experiment…we can find out that…the result is…you can seediscover… 连词成句，再用上恰当的过渡词连句成篇：
高中英语作文：实验报告 第一篇：高中英语作文：实验报告 烧水的实验报告英语作文范文一 Water Boiling Aim: 1.To find out / observe the temperature when water is boiling. 2.To find out what happens when water is boiling.Apparatus: a test tube, water, thermometer, Bunsen burner Method: 1.Half-fill the test tube with water. 2.Put the thermometer in the test tube with water. 3.Heat the water in the test tube and watch the reading of the thermometer.Result: When the temperature reaches 100 degrees centigrade, bubbles begin to appear.Conclusion: 1.Water boils when the temperature reaches 100 degrees centigrade. 2.A lot of bubbles appear during the boiling.范文二The aim of the experiment is to observe the temperature when water boils and what happens in water during boiling.T o carry out the experiment, you need the following equipment: a test tube, water, thermometer and Bunsen burner.First, half-fill the test tube with water.Then put the thermometer in it.Finally, heat the water, and observe the number / reading of thermometer.Now you can see that when the temperature reaches 100 degrees centigrade, plenty of bubbles form on the water surface.So we can draw a conclusion: water starts boiling at 100 degrees centigrade;in addition, plenty of bubbles appear during boiling.
求一篇英文的化学实验报告范文（ Chemistry Lab sample (This is one of my Chemistry 11 lab assignment。) Title: Cooling and Heating Curves of a Pure Substance Objectives: to investigate the cooling process for liquid paradichlorobenzene to investigate the heating process for solid paradichlorobenzene Materials: Apparatus: rin stand and ring support buret clamp bunsen burner; wire gauze with ceramic centre; test tube(18mm*150mm); beaker(400ml); 2 thermometers; lab apron; safety goggles. Reagent: paradichlorobenzene Procedure: Data and observations: So generally, its the data you record throughout the lab. Data table should be customized for each lab. Conclusion: Questions and follow-up questions: Answer any question assigned at the back of the lab After all, this is only a high school lab example. If you are looking for a university chem lab template, i guess it would be more spesific in details。 well, generally, it goes like that. you can write your own one as long as you think you make clear of what you do. Have fun with it. 求一份英文实习report(300字左右) 这是范文这学期是我任教的第一学期，我担任初一级七班，八班的英语教学。 由于教学经验颇浅。因此，我对教学工作不敢怠慢，认真学习，深入研究教法，虚心向前辈学习。 经过一个学期的努力，获取了很多宝贵的教学经验。以下是我在本学期的教学情况。 因此，了解和分析学生情况，有针对地教对教学成功与否至关重要。最初接触教学的时候，我还不懂得了解学生对教学的重要性，只是专心研究书本，教材，想方设法令课堂生动，学生易接受。
Circular Bar Torsion Test 1.The purposes. i.Measure the shearing yield limit τs and the shearing strength limit τb of low carbon steel and measure the shearing strength limit τb of cast iron. ii.Learn the structure, the operation of torsion test machine. And learn the procedures of torsion test. https://www.doczj.com/doc/5b19315973.html,pare the deformation and the fracture of low carbon steel and cast iron. Analysis the reason. 2.The instruments. electronic torsion test machine, slide caliper rule. 3.Specimen. Take the standard cylinder specimen. d0=10mm. The both two ends are rectangular. 4.The theories. i.Low carbon steel torsion test.
ii.Cast iron torsion test. 5.The procedures. i.Measure the diameter d o of the specimen at the both two end and the middle. ii.Install the specimen. iii.Draw a straight line along the axis of the specimen to observe the deformation. Make the rev of motor at 3~30°/min. Observe the T-φ curve. Record the minimum yield torque τs and the ultimate torque τb. For cast-iron test only get the ultimate torque τb. iv.Uninstall the specimen, and clean up the instruments. 6.Data processing. The anti-torsion cross section coefficient: W n=πd3/16 Shearing yield limit: τs =T s/W n Shearing ultimate strength: τb =3T b/(4W n)
英文版的化学实验报告 英文版的化学实验报告 Introduction: Chemical experiments are an essential part of scientific research and education. They provide valuable insights into various chemical reactions and help us understand the properties and behavior of different substances. In this report, we will discuss the process and findings of a chemical experiment conducted to investigate the reaction between hydrochloric acid and sodium hydroxide. Experimental Procedure: 1. Materials: The materials used in the experiment included hydrochloric acid (HCl), sodium hydroxide (NaOH), distilled water, a burette, a conical flask, a pH meter, and a magnetic stirrer. 2. Preparation: A solution of hydrochloric acid was prepared by diluting a given volume of concentrated hydrochloric acid with distilled water. Similarly, a sodium hydroxide solution was prepared by dissolving a specific amount of sodium hydroxide pellets in distilled water. 3. Setup: The burette was filled with the sodium hydroxide solution, and the conical flask was placed on the magnetic stirrer. The pH meter was calibrated according to the manufacturer's instructions. 4. Titration: The hydrochloric acid solution was slowly added to the conical flask while stirring continuously. The pH meter was used to monitor the change in pH during the titration process. The addition of hydrochloric acid was stopped when
Title The title for the lab report may be provided by your lecturer. If not, you will need to make up your title. It should be brief, informative, and interesting. It is not usually a sentence. You should aim to provide just enough information in the title to avoid it being overly general. The key is to be concise and meaningful. Check with your lecturer if you need to include a title page and ensure all the relevant information is supplied. This will include your name, student number, date of the experime nt, the demonstrator’s name and the group you belong to. Introduction The introduction should be clear and concise. It should tell the reader what to expect in the report. An introduction generally includes the following elements: ? Problem – State the issue investigated by the experiment. ?Background –Briefly summarise previous research on the topic and narrow the scope of the study. ? Objectives – State the aim of the experiment and state the methods used. ? Hypothesis – If this is not already given, you must formulate this in unambiguous terms. The introduction is written in the past tense following the scientific style of writing. Materials and methods This section should contain a clear enough explanation of how you conducted the experiment so that someone wishing to replicate the procedure may be able to do so. Here you should describe the experimental design, the treatments and the apparatus you used. You should follow the rules for the conventional descriptions of chemicals. The standard practice is not to use trade names for chemicals. Instead you should use the generic or chemical names. Standard apparatus should be described in proper technical terms. Also, you should describe the procedures and methods of measurement you used. At the end of this section you should provide details of how you analysed the data. If this involved lengthy statistical calculations, these should be attached as an appendix. Results and discussion This section should be organised in a systematic way such that you first present the results and then discuss them. To report on results you should describe what happened. This is perhaps the most important section of your report because it is where you report the data upon which your conclusions are based. Accuracy, clarity of expression and systematic presentation of the data (e.g., use of tables, graphs, figures, diagrams, etc.) are key factors here. Take note that tables and figures do not simply repeat information given in the text –they are meant to summarise, amplify, or complement it. You should report first the results that bear directly on the title of your lab report. Any other interesting findings should follow this. If the experiment had more than one hypothesis, you may want to organise your results in a way that reflects this. A key
薄层色谱实验报告英文版 Thin Layer Chromatography Experiment Report Introduction: Thin layer chromatography (TLC) is a widely used analytical technique in chemistry for separating and identifying different components of a mixture. It is a simple and quick method that involves the separation of compounds based on their polarity and their interaction with a stationary phase and a mobile phase. In this experiment, we used TLC to separate and identify the components of a mixture of food dyes. Materials and Methods: The materials used in this experiment were a TLC plate, a mixture of food dyes, a developing chamber, and a solvent system consisting of ethyl acetate and hexane in a 1:1 ratio. The TLC plate was first marked with a pencil line about 1 cm from the bottom. A small amount of the mixture of food dyes was spotted on the pencil line using a capillary tube. The TLC plate was then placed in the developing chamber with the solvent system. The solvent system was allowed to move up the plate by capillary action until it reached the top. The plate was then removed from the chamber and allowed to dry. The separated components were then visualized using a UV lamp. Results: The TLC plate showed the separation of the components of the mixture of food dyes. The components were identified based on their Rf values, which is the ratio
Metal Tensile Test 1.The purpose: ①Measure the yield limit, the ultimate strength, the elongation fracture of low carbon steel. ②Measure the ultimate strength of cast-iron. ③Observe the phenomena when low carbon steel and cast-iron are pulling, work out the curve that the deformation changing with the outer force(F-△L curve). 2. The equipments and the instruments. Universal material testing machine, screw micrometer. 3. Sample. In this experiment, we choose “ten times sample”, which means L o=10d o. 4.The theory in this experiment. ①The experiment of pulling low carbon steel. There are 4 stages in the deformation of low carbon steel: elastic stage, yield stage, intensive stage, local deformation stage. P s is the minimum load in the second stage. And P b is the load after which the sample comes to the 4th stage. ②The experiment of pulling cast-iron. There is no yield stage in the test of cast-iron, when the load comes to the ultimate strength P b, cast-iron will broken. And
会吃鸡蛋的瓶子的实验报告英语作文 After class, the teacher came into the classroom with a glass bottle with a small mouth, a shelled cooked egg and some pieces of paper, and said with a smile, "today we are going to do a small experiment, called bottle swallowing eggs." Hearing this, the students said incredulously, "the bottle can't listen to the eggs at all." The teacher didn't answer, but smiled. The experiment began. Teacher Tang lit a little piece of paper first. After lighting it, teacher Tang quickly put the piece of paper into the bottle. But soon the fire went out. Teacher Tang put the egg on the mouth of the bottle, but the egg was not swallowed by the bottle, but stood motionless on the mouth of the bottle. Teacher Tang was not discouraged, but continued to follow the steps just now for eight times. Finally, thick smoke came out of the bottle, and teacher Tang immediately put the eggs on it. Suddenly, a classmate called, "the egg is ready to fall!" After a while, the egg "Ding Dong" fell into the bottle. What's going on? Teacher Tang told us the truth: because the paper was burned, the oxygen in the bottle was consumed, and the air pressure in the bottle was small. It was the strong air pressure outside the bottle that squeezed the eggs in.
英文实验报告格式范文 英文实验报告格式范文 Title: The Effect of Temperature on Enzyme Activity Abstract: The purpose of this experiment was to determine how temperature affects the activity of the enzyme amylase. Three different temperatures were tested: 10°C, 25°C, and 45°C. The results showed that the rate of reaction increased as the temperature increased up to 45°C. However, at temperatures above 45°C, the rate of reaction began to decrease due to denaturation of the enzyme. The optimal temperature for amylase activity was found to be 45°C. These findings have important implications for the use of enzymes in industrial processes. Introduction: Enzymes are biological catalysts that speed up chemical reactions without being consumed in the process. They are essential for life and are used in a wide range of industrial processes. Enzyme activity is affected by a number of factors, including temperature, pH, and substrate concentration. Temperature is one of the most important factors affecting enzyme activity. Enzymes have an optimal temperature at which they work most efficiently. At temperatures above or below this
determination of heavy metals in soil by atomic absorption spectrometry(aas) name: xufei group: the 3rd group date: sep. 20th 2012 part 1 the introduction 1.1the purposes (1)learn how to operate the atomic absorption spectrometry; (2)learn how to do the pretreatment of soil samples; (3)get familiar with the application of atomic absorption spectrometry. 1.2the principles atomic absorption spectrometry (aas) is a technique for measuring quantities of chemical elements present in environmental samples by measuring the absorbed radiation by the chemical element of interest. this is done by reading the spectra produced when the sample is excited by radiation. the atoms absorb ultraviolet or visible light and make transitions to higher energy levels . the concentration is calculated based on the beer-lambert law. absorbance is directly proportional to the concentration of the analyte absorbed for the existing set of conditions. the concentration is usually determined from a calibration curve, obtained using standards of known concentration. calibration curve method: prepare standard solutions of at least three different concentrations, measure the absorbance of these standard solutions, and prepare a calibration curve from the values obtained. then measure the absorbance of the test solution adjusted in concentration to a measurable range, and determine the concentration of the element from the calibration curve. part 2 the materials and apparatus part 3 the procedure 3.1 operating procedure for aas (2) install required hollow cathode lamp. select “t” before turning to the power and hollow cathode lamp. then select appropriate la mp current and preheat for 30min. (3) make sure electrical meter to point to zero and then turn on high-voltage power. (4) select appropriate slit width. (5) rotate monochromator and select required wavelength. if the power meter is too high or low, adjust negative high voltage until the meter reads full scale. (6) adjust light point and wavelength so that the meter represents the maximum value. (8) inject distilled water into the flame and continue to preheat the burner. inject distilled water into the flame after each sample. (9) select “e”, inject blank solution into the flame and adjust the meter to zero. (10) optimize analysis conditions and measure standard solution and samples. (12) select “t” before turning off high voltage power, decrease lamp current and then turn off the lamp. at the same time, all buttons should be on original positions. (13) check the equipment before leaving the laboratory.
英文版实验报告 英文版实验报告 Introduction: In this report, we present the findings and analysis from a recent experiment conducted to investigate the effects of caffeine on cognitive performance. Caffeine, a widely consumed psychoactive substance, is known to have stimulant effects on the central nervous system. The objective of this experiment was to examine whether caffeine could enhance cognitive abilities such as attention, memory, and reaction time. Methodology: Participants: A total of 50 healthy adult volunteers aged between 18 and 30 years were recruited for the study. They were randomly assigned to two groups: the experimental group (received caffeine) and the control group (received a placebo). Procedure: Participants arrived at the laboratory after an overnight fast and were instructed to abstain from consuming any caffeinated beverages or food for at least 12 hours prior to the experiment. They were then given either a capsule containing 200mg of caffeine or a placebo capsule. The experimenters, as well as the participants, were blinded to the group assignments. Cognitive tests: After a 30-minute absorption period, participants completed a battery of cognitive tests. These included a sustained attention task, a memory recall task, and a reaction time test. The tests were designed to measure