What Happened If You Didn't Take The College Entrance Examination? I Recommend

Lu Shixian immediately questioned Liu Xianhua's professionalism.

"I said that you are also a dignified doctor anyway. How can you need to detect reducing substances in what you are talking about?"

Liu Xianhua had a subconscious reaction just now, how could he admit cowardice now, so he retorted: "How is it impossible? Maybe there is no money to eat and eat dirt?"

Lu Shixian: (￢_￢)

He can only say that he is worthy of being a doctor, and his brain is turning fast!

Lu Shixian didn't bother to argue with him, and put on the sterilized white coat, shoe covers and mask, and other precautions.

He started some preparatory work such as preparing containers, configuring reagents, and measuring instruments.

Arrange them neatly and clearly label the reagents.

Then start the registration and numbering of the inspection samples according to their own inspection purposes.

Liu Xianhua next to him had an indifferent expression that suddenly became more and more weird.

For scientific research, there is a saying that is true, that is, details determine success or failure.

Lu Shixian's operation may seem inconspicuous, but it is the cornerstone of the success of the entire experiment.

And this kind of thing can only be understood by those who really step into scientific research.

He is well aware of Lu Shixian's situation. Even if he is the first gold medalist in the national competition, the so-called biological competition experiment has no entry in the face of real scientific research.

So before the experiment started, he finally couldn't bear it anymore and asked him.

"Lu Shixian, where did you learn this skill?"

Lu Shixian knew what he wanted to ask, and threw the pot to his instructor without any psychological burden.

"The coach of my high school competition team, see if you can do it?"

Liu Xianhua became more and more puzzled, did he not keep up with the times?

Do high school teachers have this level now?

However, now is not the time to dwell on this.

Because Lu Shixian's experimental operation has already started.

The step of testing reducing substances is quite complicated, because there are too many things that need to be measured, and he needs to measure a lot of samples, so he has a lot of work today.

What he needs to determine are the total amount of reducing substances, active reducing substances, fe2+, n2+ and active organic reducing substances.

Among them, soil reducing substances were extracted by al2(4)3, and the total amount of reducing substances was determined by potassium dichromate oxidation method.

The content of active reducing substances was determined by potassium permanganate titration.

The content of fe2+ should be determined by o-phenanthroline colorimetric method, and the content of n2+ should be measured by potassium periodate colorimetric method.

The content of active organic reducing substances is the difference between the content of active reducing substances and the content of fe2+.

A morning of doing this is about to pass, and there are only a few samples left that have not been tested.

In this case, Lu Shixian didn't rest anymore, and even skipped lunch.

This is highly unusual for him, as he has always maintained a normal, regular schedule of sleep and meal times.

But compared with scientific research, these have a lower priority.

In the past, sometimes forgetting to eat and drink water was common.

So by doing this, the time came to more than two o'clock in the afternoon.

The experiment ended here, and he also got the data he needed.

So he started to turn off the power, the desk lamp, deal with the dirt and the countertop, and then arrange the things on the test bench neatly.

Finally, habitually put the waste liquid and waste into the recycling device.

He took off his work clothes, exhaled lightly, and walked out of the laboratory to stretch his muscles and bones.

His original plan was to complete the measurement in half a day, but the plan he made was disrupted not once or twice.

As long as the task can be successfully completed today, it will meet the psychological expectations.

Liu Xianhua who was next to him followed him out, already not knowing what to say.

Watching his movements change from jerky to smooth, it condenses all the journey from novice to veteran driver.

I thought he was more talented in theory, but I didn't expect that he seemed to be able to understand experiments by analogy.

Is this the strength of the national first gold medal champion?

It's really a monster!

He couldn't help feeling in his heart all the time.

Only then did he have the time to ask, "What's the use of testing this thing?"

"It's nothing more than some oxidation-reduction effects. This seems to be a chemical-oriented content?"

Lu Shixian has achieved his goal when he came here, and now he is in a good mood, so he made a joke with him.

"Guess, guess what I want to do?"

Liu Xianhua responded angrily: "Can you guess me or not?"

Since Lu Shixian wanted to keep it mysterious, he didn't ask in detail.

As far as he is concerned, no matter what experiments Lu Shixian does, they are all very low for his level.

"Have you finished your experiment? Then I'll slip away. You're almost done, and my paper hasn't arrived yet!"

After speaking, Liu Xianhua finally completed his mission as a tool man and ran away directly.

Lu Shixian, on the other hand, is going to fill his stomach first, and the most difficult hurdle for him has been completed.

For this kind of experiment, as long as the data is obtained, the rest of the work is very simple.

After lunch, Lu Shixian randomly found a computer in the electronic reading room of Jinling University.

The experimental design of the first question has already been completed.

The task now is to collate the test data and calculate the characteristic number of the second question.

In fact, there are specialized data processing software. In his previous life, he used more dps data processing system, statistical and atb software developed by Jiangsu and Zhejiang University.

But for this level of data processing, IMHO, he can do it with an excel spreadsheet.

The data is entered and organized using icroft excel 2008.

The data he obtained are all continuous variable data. Generally speaking, after directly sorting, finding the extreme difference, determining the number of groups and group intervals, selecting group limits and group medians, and grouping, this process is completed.

Then insert the functions mode ode, median idian, arithmetic mean avera, geometric mean oan, quartile value artile, standard deviation stdev and variance var.

Next is the third question of statistical inference.

The task he needs to complete in this step is parameter estimation, because the number of samples is not large, so he uses the value of the sample statistic as the estimated value of the overall parameter, that is, point estimation.

Then the sampling distribution is used to calculate the x2 (chi-square) distribution, t distribution, and f distribution.

The x2 distribution is the sampling distribution of variance, which describes the possibility that the variance s2 of the sample is close to the variance of the population when randomly sampled from a normally distributed population.

The t distribution is a random variable x ~ n (0, 1), y ~ x 2 ( n ), and x and y are independent, denoted as t ( n ).

The f distribution is that x and y are two independent random variables, x obeys the chi-square distribution with k1 degree of freedom, y obeys the chi-square distribution with k2 degree of freedom, these two independent chi-square distributions are divided by their respective degrees of freedom The distribution of this statistic after the ratio.

Next comes the most critical step.