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光干涉甲烷测定器，当甲烷室、空气室温度压力相等时，气体浓度与干涉条纹的移动量成反比。（)
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更多“光干涉甲烷测定器，当甲烷室、空气室温度压力相等时，气体浓度与干涉条纹的移动量成反比。（)”相关的问题
第1题
用钢管将压力为0．32MPa(表压)、温度为298K、流量为0．35Nm3／s的天然气(以100％甲烷计)送往150m(包括局部阻力的当量长度)外的燃烧喷嘴，要求进喷嘴前燃气的压力不低于0．07MPa(表压)。设流动为等温，天然气的平均摩尔质量为16kg／kmol，黏度为1．0×10-5Pa．s，大气压为0．10MPa。试求输送管道的直径。
第2题
A．东西伯利亚北极大陆架深水区甲烷的含量高于浅水区
B．最新研究表明东西伯利亚地区开始进入新一轮寒冷期
C．海水深度与甲烷氧化为二氧化碳之间不存在线性关系
D．最新研究表明甲烷造成的温室效应并不比二氧化碳大
第3题
A.东西伯利亚北极大陆架深水区甲烷的含量高于浅水区
B.最新研究表明东西伯利亚地区开始进入新一轮寒冷期
C.海水深度与甲烷氧化为二氧化碳之间不存性关系
D.最新研究表明甲烷造成的温室效应并不比二氧化碳大
第5题
某股常压、20℃的含尘空气，其流量为5000m3/h，其所含尘粒的密度为2000kg/m3，欲用降尘室处理，要求净化后气流中不含直径大于12μm的颗粒，试求需要的降尘总面积。若所用降尘室底面长5m、宽3.2m，则这样的降尘室需要设置多少块隔板方能完成上述净化任务。
第8题
A.A. 未加催化剂
B.B. 未加压力
C.C.体系中没有甲基自由基
D.D. 体系中没有氯自由基
第10题
第11题
Plant Gas
Scientists have been studying natural sources of methane (甲烷，沼气) for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist(地球化学家) at the Max Planek Institute for Nuclear Physics in Heidelberg, Germany. Now Keppler and his colleagues find that plants, from grasses to trees, may also be sources of the greenhouse gas. This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment.
Previously, researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that microbes(微生物) need to be in environments without oxygen to produce methane. Methane is a greenhouse gas, like carbon dioxide. Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming.
In its experiments, Keppler's team used sealed chambers (室，房间；腔) that contained the same concentration of oxygen that Earth's atmosphere has. They measured the amounts of methane that were released by both living plants and dried plant material, such as fallen leaves.
With the dried plants, the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C..At 30 degrees C., they found, a gram of dried plant material released up to 3 nanograms(微克) of methane per hour (One nanogram is a billionth of a gram. ). With every 10-degree rise in temperature, the amount of methane released each hour roughly doubled.
Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled (增加三倍) when living and dead plant was exposed to sunlight.
Because there was plenty of oxygen available, it's unlikely that the types of bacteria(bacterium 的复数，细菌) that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions. That's another strong sign that the gas came from the plants and not soil microbes.
The new finding is an "interesting observation," says Jennifer Y.King, a biogeochemist(生物地球化学家) at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane, they may prevent plant-produced methane from reaching the atmosphere. Field tests will be needed to assess the plant's influence, she notes.
What was scientists' understanding of methane？
A．It was produced from plants.
B．It was not a greenhouse gas.
C．It was produced in oxygen-free environments.
D．It traps more heat than any other greenhouse gas.
