Microscope

In history of the earth, there have lived at least two million different species of life. But no other species like human beings have so much impact on the earth, on the environments, and on other lives. It is because of making and using of tools that make us so powerful and distinguish us from animals.

Tools extend our biological capabilities. For example, cars extend our capability of walking, telephones enable us to hear people from thousands of miles away, and telescopes make it possible for us to see far away in the space.

A microscope is a tool or an instrument that helps us to see objects that are too small to be seen with the naked eyes. Here shows a picture of a microscope. The main parts of a microscope are eyepiece lens and objective lens. And both eyepiece and objective lens are magnifying glasses.

It is recorded that as early as 2000 years ago, people already knew that some glasses or crystals with thicker in the center and thinner at the edge could make things look larger. And that was why they were called magnifying glasses. But magnifying glasses were not used much until invention of spectacles in the end of the 13th century.

In about 1590, two Dutch spectacle makers, while experimenting with several lenses in a tube, discovered that objects appeared greatly enlarged. That tube containing several lenses in it was the forerunner of both microscopes and telescopes.

Two remarkable contributions were made with microscopes in science: discovery of cells and discovery of microorganisms such as bacteria and virus. Discoveries of cells and microorganisms were milestones in development of science and had great influence in development of biology and medicine.

There are many different kinds of microscopes. But basically they belong to two kinds: optical microscopes and electron microscopes. Optical microscopes use visible light to image objects, and electron microscopes use electron beams to image objects. The magnification of an optical microscope is usually 500 to 1000 times. The maximum is 2000 times. An electron microscope can reach magnification of 2,000,000 times, under which virus and large molecules can be seen.

Here are images of pollens under microscopes. Pollens are male cells of plants. They are reason or culprits for allergy many people suffer in the spring. The left is an image of pollens under a optical microscope and the right is an image of pollens under an electronic microscope.

Microscopes are indispensable tools in fields like cell biology, microbiology, pathology including plant pathology, animal pathology and human pathology, nanoscience that deals with materials at micro level and forensic science that deals with criminal investigation etc.

Human beings have actually found another world with microscopes.

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The above is one of my Toastmasters speeches. The speech is based on a project titled "Technical Briefing".

Yu Harnesses the Yellow River

Yellow River is the mother river of China. She is the second longest river in China and the sixth in the world. It is believed that Chinese civilization originated from an area called Yellow River basin.

Yellow River was both China’s pride and China’s sorrow. Yellow River was a blessing because it provided water and fertile soil for agriculture and made it possible to build cities along the river. Yellow River was a pain to Chinese people because it was prone to flooding. Historical documents recorded that in last 3000 years, Yellow River has flooded for more than one thousand and five hundred times, a flood every two years！Millions of people had been killed and hundreds of cities had been ruined by Yellow River floods.

In about 2100 BC, that is more than 4000 years ago, Yellow River flooded greatly and frequently. At that time, in the area of present China lived numerous tribes and they allied together. The floods caused great suffering to people.

Gun, chief of a tribe, was initially selected to lead people of all tribes to manage the river. Gun led people fighting floods for nine years but didn't succeed. Gun's method was building dams and levees to block the floods. The dams and levees were built higher and higher, but flooding water was also getting higher and higher; eventually water overflowed the dams and destroyed them.

Gun was dismissed after his failure. Yu, Gun’s son, was then assigned as chief to continue leading people to fight floods. Yu got the lessons from his father. He first made a thorough survey on the geographic features along the entire river and the flooding courses. Then he assembled people dredging rivers making water flow faster and building new rivers based on the natural flooding courses and led the flooding water into the sea.

It is said Yu assembled and put 270,000 people into action; and they worked hard for 13 years. Finally the floods were subdued.

Yu was a dedicated leader. He was just married when he was appointed as the chief. In 13 years, he never entered his home even though he passed his home for three times.

By harnessing Yellow River, Yu not only subdued the floods, but also united people. Later, he founded the first dynasty of China, Xia.

Yu was arguably the first king of China. People respectfully call him DaYu , which means Yu, the great.

Today, I tell the story about Yu. It is not because he was the founder of first dynasty of China, nor because he had a great influence in the development of Chinese civilization, but because of his method of fighting floods.

Facing rampant flooding water, Yu's method was not to block it but channel it. This is something worth remembering and thinking.

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This is one of my Toastmasters' Speeches; and this speech is based on a project titled "Bringing History to Life".

Utilization of Microalgae for Biofuels Production

As we know, modern society relies heavily on fossil fuels. 80-90% of all energy consumed in the world is from fossil fuels. Fossil fuels include oil, natural gas and coal. They originated from plants and animals that lived on the earth millions of years ago. The resources of fossil fuels are limited and non-renewable.

The first slide shows the history and the future prediction of worldly oil production. It is generally believed that worldly oil production will peak in less than 10 years. As you can see from the figure, USA and Russia passed their oil production peaks decades ago, in 1970s and 1990s respectively.

After world oil production peaks and declines, the world will face a severe situation. The situation is that the world simply cannot produce enough fossil oil to meet the demand from transportation.

This oil gap for transportation has to be filled. Biofuels are one of the candidates to fill this oil gap. Biofuels are derived from biomass. And biomass used for producing biofuels can be grains, hay, weeds, woods and others.

The first generation biofuels derived from crops. For example, in USA, corns are used for producing ethanol; in Brazil sugarcane are used for producing ethanol; and soybeans are widely used for producing biodiesel. But corn, sugarcane and soybean are crops. The main problem facing crop-derived biofuels is conflict between food production and biofuels production. Other problems concerning crop-based biofuels production include deforestation, high production cost and limited potential. Take the limited potential for example: Even if all the corn currently produced in the USA were used for producing ethanol, it could only replace about 15% of oil currently consumed in the USA.

Microalgae are single-celled lower plants that make seas, lakes and rivers green. When you walk around a natural pond in the spring and summer, you can find the surface of water is covered by green stuff. That are microalgae. Microalgae are "plants" because they can grow by using sunlight, CO2 and water.

There are several advantages of using micro-algae for biofuels production over crops.

First, microalgae grow much faster than land plants. It can grow 7 to 30 times faster than the next best crop. Under the optimum conditions, microalgae can double its biomass in several hours.

Second, cultivation of microalgae doesn’t compete for farmland. Algae can be grown on land that is not suitable for crops, for instance, arid land, land with excessively saline soil, and drought-stricken land. Moreover, 70.8% of the earth’s surface is cover by water. Microalgae can be cultivated in open ponds, and even in the sea.

Third, algae-based biofuels are CO2 neutral, which does not deteriorate Global Warming effect. Algae absorbs CO2 from atmospheres when it grows and the CO2 is released back into atmospheres when the biofuels is used.

Fourth, microalgae can be harvested daily or any time needed, not like crops that are limited by their long growth cycle.

The main challenges facing algae-based biofuels are lack of cost-effective technologies to cultivate, harvest microalgae and to process microalgae into biofuels. But this is not strange. Human Beings have been planting crops, such as corn, sugarcane and soybean, for at least five thousand years, but cultivating and processing microalgae for biofuels is still in experimental stage. There is a lot of space to develop an improve algal cultivation, harvesting and processing technologies.

Utilizing microalgae for biofuels production will bring many benefits to the society and the country, such as breaking the USA’s dependence on foreign oil, creating a new source of green energy and adding job opportunities.

Microalgae are one of the most promising sources for biofuels production. But to make it reality, renovation of technology in this area is needed. And to renovate the technology, more money and more human resources should be invested.

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The above is one of 8 - 10 min speeches I delivered in my Toastmasters club. The speech is based on AC#2: The Proposal.

Helping Seedlings Grow by Pulling Them Upwards

"Helping seedlings grow by pulling them upwards” is an English Translation of a Chinese idiom “Ba Miao Zhu Zhang”. The idiom originated from a story and the story goes like this:

In ancient China, there was a farmer who grew rice. He hoped the rice seedlings would grow fast and was expecting a good harvest. So he went to the field to watch the rice seedlings every day. It seemed to him the seedlings were growing very slowly. He became anxious about the seedlings and said to himself: “I should do something to help the seedlings grow faster.”

He thought and thought and then had a great idea. "Why don’t I pull the seedlings upwards a little bit and that would help them grow faster.” After thinking of this, he went down to the field and pulled every seedling upward a little bit. After doing that, the seedlings did look taller.

Looking at the taller seedlings, he was happy though exhausted from the hard work. On his way back home, he couldn’t help thinking how smart and hardworking he was. He even couldn’t understand why people hadn’t discovered this method before.

However, several days later when he went back to field, he found all the seedlings had dried up and died.

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The basic meaning of “Helping seedlings grow by pulling them upwards” is spoiling things by excessive enthusiasm. It describes behaviors of people who are too eager to get things done only to make the things worse. I know I made such mistakes. Can you find examples of “Helping seedlings grow by pulling them upwards" in history and real life, for example, in some parents who want to help their children, in some religious groups that want to influence their followers, or in some governments that want to control their people?

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The above is a 4-6 minute speech I delivered in my Toastmasters club. The speech is based on a project titled "The Moral of a Story".

The Sun and the Solar Energy

If you are interested in mythologies of sun god or goddess, you will be able to find numerous versions in different cultures including Chinese, Korean, Japanese, Egyptian, Greek, Indian and many others.

The first slide shows the Indian sun god and Greek sun god. I personally like the story of Greek sun god, Apollo, very much. I think the story of Apollo is comparable to the best of William Shakespeare’s plays.

However everyone here knows that the sun is the only star in our solar system. Comparison between the sun, the earth and other planets in size is shown in the second slide. The sun is much larger than the earth and other planets. Actually the volume of the sun is over one million times larger than that of the earth.

The sun is an enormous ball of burning gases. The main elements of the sun are hydrogen and helium. Since there is no oxygen on the sun, the energy of the sun does not come from general sense of burning hydrogen, but from hydrogen nuclear fusion, a process similar to that happening in a hydrogen bomb when it explodes.

The sun produces enormous light per second and it has been doing that for billions of years. Up to now, the largest power plant in the world is the Chinese Three Gorge power plant, which can produce 18,000 Megawatts (one million) of power per year. However, the sun puts out the same amount of energy in the form of light per second as a billion of the largest power plant in the world would put out in a year. This number is enormous, even difficult to imagine.

The sun light absorbed by the earth atmosphere, oceans and land is called solar energy. The solar energy the earth receives per hour is equivalent to all the energy humans currently consume in a year.

About 0.1% of the solar energy has been captured by photosynthesis, transferring the light energy into chemical energy. Plants make their own food by Photosynthesis, and animals and humans have to eat plants or other animals to obtain their energy. So the energy to sustain almost all the life on the earth comes from the Sun.

Here lists the energy sources originally from the sun. Currently, 86% of energy we are using are form fossil fuels: coal, oil and natural gas. Fossil fuels were solar energy fixed by plants millions of years ago; and bioenergy, hydropower, solar power, wave power, wind power are all originally from solar energy. The only exceptions are nuclear power, tidal energy, and Geothermal energy.

Without the sun, life on the earth simply wouldn’t exist. We are so blessed that the sun provides us with free and clean energy. How can we be grateful enough for the Sun? The only thing we can do is to make good use of the solar energy.

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The above is one of 5-7 min speeches I delivered in my Toastmasters Club.

Liang and Zhu, Chinese Romeo and Juliet

It is said about one thousand and six hundred years ago, in east of China, there was a beautiful and intelligent girl. Her name was Zhu. At that time, females couldn’t go to school but Zhu was eager to study.

She managed to convince her family to allow her to go to school in disguise as a man.

On her journey to school, Zhu met Liang, a young man who was going to the same school as her. They became friends at first meeting. In the next three years, they studied together and behaved like "brothers". Gradually, Zhu fell in love with Liang.

One day, Zhu received a letter from her family, asking her to return home. Zhu had no choice but leave school and Liang. However, in her heart, she was deeply in love with Liang and was determined to be with him forever.

So she went to her teacher’s wife for help. The teacher’s wife actually recognized her to be a girl long time ago, and promised to help her.

On the way Liang saw Zhu off. Zhu hinted to Liang that she was a girl, but Liang was somehow a bookworm and didn’t understand Zhu’s hint. Finally Zhu came up with an idea and told Liang that she had a beautiful sister and would like to introduce her sister to be Liang’s wife. Liang was very happy and looked forward to meeting Zhu’s sister.

However, when Zhu went home, her family had already arranged a marriage for her. The man Zhu was arranged to marry was from a very rich and powerful family.

Zhu confessed her love with Liang to her parents and resisted to the arranged marriage. She even vowed that she would kill herself rather than marry another man. But his father didn’t agree to the possible marriage between Liang and Zhu, and threatened that if she didn’t agree to the arranged marriage, Liang’s life would be at risk if the powerful family got angry with her breaking the arranged marriage. Since Zhu loved Liang and didn’t want Liang to be hurt, she finally decided to submit herself to the arranged marriage.

At school, with the reminding of the teacher’s wife, Liang finally realized that Zhu was a girl and the sister Zhu wanted to introduce to him was actually Zhu herself. After knowing this, Liang was very happy and couldn’t wait any more to see Zhu again.

However, when Liang arrived at Zhu’s home, he was heartbroken to learn that Zhu had to marry another man. There was no way for them to break the feudal customs or rules set at that time.

Since then, Liang got sick and died later.

On the day Zhu was sent for wedding, a mysterious wind brought the team passing by Liang’s grave. When Zhu saw Liang's grave, she cried in bitter despair and begged for the grave to open up.

Suddenly, the grave opened with a strike of thunder. Without any hesitation, Zhu threw herself into the grave and united with Liang.

Their spirits turned into a pair of beautiful butterflies. They flied together and never separated again.

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The above is a 6 - 8 min speech I delivered in my Toastmasters club (AC#4 Tell a story)