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阅读理解.In 1661 King Charles II of England commissioned Sir Christopher Wren to create a series of microscopical studies. Wren obliged, but after a few presentations found he didn’t have the time and gave up the project to an upcoming scientist with something of a knack for drawing and mechanics. The rest is history.
Robert C。Hooke was 26 years old when he took the assignment from Wren and joined the Royal Society for Scientists. A self-educated child genius, he showed technical talent by recreating the entire inner workings of a clock out of wood, then assembling it to run. Hooke also taught himself technical drawing, a skill he used to capture observations through his microscope.
Hooke applied his technical abilities to invent ways of controlling the height and angle of microscope, as well as mechanisms of variations in light allowed Hooke to see new detail, and he used multiple sources of lighting before producing any single drawing. Hooke’s technical efforts created magnifications of 50x, enabling insight to a world not yet known in the 1600s.
King Charles only requested insect studies, but Hooke went beyond his commission and looked at everything from fabric, leaves, glass and even frozen urine. Hooke did things like letting a louse (虱子) suck from his hand to observe how his blood traveled through its body. He also stung himself with nettles (荨麻) to see where and how the poison was pumped into his hands.
When Hooke viewed a thin cutting of cork he discovered empty spaces contained by walls, and termed them pores, or cells. The term cells stuck and Hooke gained credit for discovering the building blocks of all life. Hooke calculated the number of cells in a cubic inch to be 1,259,712,000, and while he couldn’t grasp the full effect of his discovery, he did at least appreciate the sheer number of these cells.
Why did the scientist appointed by the king give up the project?
Researchers have developed a process to remove contaminants from oil sands wastewater using only sunlight and nanoparticles that is more effective and inexpensive than conventional treatment methods.
Frank Gu, a professor in the Faculty of Engineering at the University of Waterloo and Canada Research Chair in Nanotechnology Engineering, is the senior researcher on the team that was the first to find that photocatalysis — a chemical reaction that involves the absorption of light by nanoparticles — can completely eliminate naphthenic acids in oil sands wastewater, and within hours. Naphthenic acids pose a threat to ecology and human health. Water in tailing ponds left to biodegrade naturally in the environment still contains these contaminants decades later.
“With about a billion tons of water stored in ponds in Alberta, removing naphthenic acids is one of the largest environmental challenges in Canada,” said Tim Leshuk, a PhD candidate in chemical engineering at Waterloo. He is the lead author of this paper and a recipient of the Vanier Canada Graduate Scholarship. “Conventional treatments people have tried either haven’t worked or if they have worked, they’ve been far too impractical or expensive to solve the size of the problem. Waterloo’s technology is the first step of what looks like a very practical and green treatment method.”
Unlike treating polluted water with chlorine or membrane filtering, the Waterloo technology is energy-efficient and relatively inexpensive. Nanoparticles become extremely reactive when exposed to sunlight and break down the persistent pollutants in their individual atoms, completely removing them from the water. This treatment depends on only sunlight for energy, and the nanoparticles can be recovered and reused indefinitely.
Next steps for the Waterloo research include ensuring that the treated water meets all of the objectives Canadian environmental legislation and regulations required to ensure it can be safely discharged from sources larger than the samples, such as tailing ponds.
What is photocatalysis?