全氮 total nitrogen

氮转化 nitrogen transformation

氮循环 nitrogen cycle

It is commonly supposed that the health of Long Island Sound is chiefly the responsibility of the shoreline communities in Long Island, Westchester County and Connecticut. This is largely true. It is also true, however, that New York City has long been a major contributor to the environmental ills that torture this noblest of American estuaries.
The main reason is four old municipal sewage treatment plants on the East River. Every day of every year, these plants deposit hundreds of thousands of gallons of partly treated wastewater into the river, which then, with tidal certainty, propels the polluted water into the Sound itself
The most damaging of the pollutants leaving the plants is nitrogen—useful as a fertilizer on land but, in sufficient quantities, fatal to bodies of water like the Sound, where it stimulates the growth of bacteria and algae and robs the water of oxygen. This condition is known as hypoxia, and it suppresses marine life. Roughly half the nitrogen comes from treatment plants and other sources in about 80 shoreline communities, the other half comes from the New York City plants.
It is thus cause for great celebration that the city agreed last week to settle a longstanding legal action and spend at least $700 million to upgrade these four plants, cutting their nitrogen output by nearly 60 percent by 2017. Audubon New York, a leader among the environmental groups that helped shape the agreement and move it forward, when negotiations seemed to falter, called the agreement an historic moment in the struggle to restore the Sound to good health.
In retrospect, the most important moment in that struggle the moment from which all else has flowed, including last week’s agreement—came m 1994, when New York and Connecticut. after sustained pressure from the federal Environmental Protection Agency, approved a comprehensive plan to clean up the Sound. The city’s main responsibility was to modernize its sewage treatment plants. The Giuliani administration left the bulk of the task to Mayor Michael Bloomberg.
Alarmed by the project’s estimated $1.3 billion price tag, Mr. Bloomberg dispatched Christopher Ward, then the environmental commissioner, to Europe and elsewhere to find new, more cost-efficient waste treatment technologies. In due course, Mr. Ward and his counterpart in Albany, Erin Crotty, reached an agreement in principle to reform the plants at well under the original cost. Mr. Ward and Ms. Crotty left public service, but after further debating aimed partly at ensuring that future city administrations could not wiggle out of the deal, and after further prodding by Attorney General Eliot Spitzer, their successors. Emily Lloyd and Denise Sheehan, brought the matter to a close.
This does not mean the Sound is no longer at risk. The Sound passes through the densest population corridor in the country, and will remain forever stressed by the 20 million people who live within 50 miles of its shores. Thus the shoreline communities in Long Island, Westchester and Connecticut must do more than ever to contain pollution.
According to the text, the following statements about nitrogen are true EXCEPT______.

A:nitrogen suppresses marine life B:nitrogen is a fertilizer Which helps plants grow C:nitrogen in large quantities is fatal to bodies of water D:nitrogen can rob water of oxygen

Text 3
Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a dive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper.
The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 30 meters in seawater a diver is exposed to a pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meters are present at five times their usual pressure. Nitrogen, which composes 80 per cent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen cause under these pressurized helium does not exert a similar narcotic effect.
As a scuba diver descends, the pressure of nitrogen in the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. The reverse occurs when the diver surfaces; the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.
Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism. To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

What does the passage mainly discuss（）

A:The equipment divers use. B:The effects of pressure on gases in the human body. C:How to prepare for a deep dive. D:The symptoms of nitrogen bubbles in the bloodstream.

Text 3
Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a dive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper.
The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 30 meters in seawater a diver is exposed to a pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meters are present at five times their usual pressure. Nitrogen, which composes 80 per cent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen cause under these pressurized helium does not exert a similar narcotic effect.
As a scuba diver descends, the pressure of nitrogen in the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. The reverse occurs when the diver surfaces; the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.
Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism. To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

It can be inferred from the passage that which of the following presents the greatest danger to diver（）

A:Pressurized helium. B:Nitrogen diffusion. C:Nitrogen bubbles. D:An air embolism.

It is commonly supposed that the health of Long Island Sound is chiefly the responsibility of the shoreline communities in Long Island, Westchester County and Connecticut. This is largely true. It is also true, however, that New York City has long been a major contributor to the environmental ills that torture this noblest of American estuaries.
The main reason is four old municipal sewage treatment plants on the East River. Every day of every year, these plants deposit hundreds of thousands of gallons of partly treated wastewater into the river, which then, with tidal certainty, propels the polluted water into the Sound itself
The most damaging of the pollutants leaving the plants is nitrogen—useful as a fertilizer on land but, in sufficient quantities, fatal to bodies of water like the Sound, where it stimulates the growth of bacteria and algae and robs the water of oxygen. This condition is known as hypoxia, and it suppresses marine life. Roughly half the nitrogen comes from treatment plants and other sources in about 80 shoreline communities, the other half comes from the New York City plants.
It is thus cause for great celebration that the city agreed last week to settle a longstanding legal action and spend at least $700 million to upgrade these four plants, cutting their nitrogen output by nearly 60 percent by 2017. Audubon New York, a leader among the environmental groups that helped shape the agreement and move it forward, when negotiations seemed to falter, called the agreement an historic moment in the struggle to restore the Sound to good health.
In retrospect, the most important moment in that struggle the moment from which all else has flowed, including last week’s agreement—came m 1994, when New York and Connecticut. after sustained pressure from the federal Environmental Protection Agency, approved a comprehensive plan to clean up the Sound. The city’s main responsibility was to modernize its sewage treatment plants. The Giuliani administration left the bulk of the task to Mayor Michael Bloomberg.
Alarmed by the project’s estimated $1.3 billion price tag, Mr. Bloomberg dispatched Christopher Ward, then the environmental commissioner, to Europe and elsewhere to find new, more cost-efficient waste treatment technologies. In due course, Mr. Ward and his counterpart in Albany, Erin Crotty, reached an agreement in principle to reform the plants at well under the original cost. Mr. Ward and Ms. Crotty left public service, but after further debating aimed partly at ensuring that future city administrations could not wiggle out of the deal, and after further prodding by Attorney General Eliot Spitzer, their successors. Emily Lloyd and Denise Sheehan, brought the matter to a close.
This does not mean the Sound is no longer at risk. The Sound passes through the densest population corridor in the country, and will remain forever stressed by the 20 million people who live within 50 miles of its shores. Thus the shoreline communities in Long Island, Westchester and Connecticut must do more than ever to contain pollution.

According to the text, the following statements about nitrogen are true EXCEPT（）

A:nitrogen suppresses marine life B:nitrogen is a fertilizer Which helps plants grow C:nitrogen in large quantities is fatal to bodies of water D:nitrogen can rob water of oxygen

{{B}}第二篇{{/B}}

What element enables the ceramic tape to lower its temperature?

A:Copper. B:Liquid nitrogen. C:Clay. D:Calcium.

第二篇 Superconductor Ceramic(陶瓷) An underground revolution begins this winter．with the flip(轻击)of a switch，30，000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice．cold high．performance cables．Other American cities are expected to follow Detroit’s example in the years ahead．which could conserve enormous amounts of power． The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors．A superconductor is a material that transmits electricity with little or no resistance．Resistance is the degree to which a substance resists electric current．All common electrical conductors have a certain amount of electrical resistance．They convert at least some of the electrical energy passing through them into waste heat．Superconductors don’t?No one understands how superconductivity works．It just does． Making superconductors isn’t easy．A superconductor material has to be cooled to an extremely low temperature to 10se its resistance．The first superconductors，made more than 50 years ago，had to be cooled to-263 degrees Celsius before they lost their resistance．Newer superconducting materials 10se their resistance at-143 degrees Celsius． The superconductors cable installed at the Frisbie station is made of a ceramic material that contains copper．oxygen．bismuth(铋)。strontium(锶)．and calcium(钙)．A ceramic is a hard．strong compound made from clay or minerals．The superconducting ceramic has been fashioned into a tape that is wrapped lengthwise around a long tube filled with liquid nitrogen．Liquid nitrogen is supercold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance． The United States loses an enormous amount of electricity each year to resistance．Because cooled superconductors have no resistance．they waste much less power．0ther cities are watching the Frisbie experiment in the hope that they might switch to superconducting cable and conserve power．too． What element enables the ceramic tape to lower its temperature?

A:Copper． B:Liquid nitrogen．． C:Clay． D:Calcium