但当我们用化学方法分析这些细胞时，我们发现了一些非常有趣的东西，其中有一种化学物质，是一种叫做端粒酶的酶。
But when we analyze these cells chemically, we find something very interesting, a chemical in them, an enzyme called telomerase.
《化学入门》意在论及有机化学的重要问题。
Introduction to Chemistry aims to cover important topics in organic chemistry.
他说，一种可能性是，眼泪会从身体中释放出某些化学物质，这些化学物质是在压力下积聚起来的。
One possibility he says is that tears discharge certain chemicals from your body, chemicals that build up during stress.
为了研究大麻素的作用，研究人员给新生老鼠注射了一种化学物质，这种化学物质可以阻止大麻素到达它们大脑中的受体。
To investigate the function of cannabinoids, researchers injected newborn mice with a chemical that is known to block cannabinoides from reaching their receptors in the brain.
此外，还有一个家庭危险废物丢弃站，存放禁止掩埋的化学品（油漆、杀虫剂和其他化学品）。
In addition, there is a household hazardous waste drop-off station for chemicals (paints, pesticides, other chemicals) that are banned from the landfill.
报告说，正在发育的大脑特别容易受到这些产品里可能含有的某些化学物质的毒性影响，而这些化学物质造成的损害可能是永久性的。
The developing brain, the report says, is particularly vulnerable to the toxic effects of certain chemicals these products may contain, and the damage they cause can be permanent.
你看，原来某些微生物是化学合成的——它们不需要阳光，因为它们从化学反应中获取能量。
You see, it turns out that certain microorganisms are chemosynthetic—they don't need sunlight because they take their energy from chemical reactions.
而细菌呢，有点像通过化学合成的方式来为管虫提供食物，记得之前讲过的化学作用吧。
The bacteria, well the bacteria kind of feed the tubeworms through chemosynthesis, remember, that chemical reaction I described earlier.
我们会观察土壤的化学性质——比如某个地方的土壤里有多少氮或者镁——然后与附近土壤的化学性质作比较。
We look at soil chemistry—for example, how much nitrogen or magnesium there is in the soil in one spot—and we compare it with the chemistry of the soil a short distance away.
每一种样式代表一种不同的化学元素，所以光谱线的不同集合或模式意味着这颗恒星有不同的化学成分。
Each pattern stands for a distinct chemical element, and so different sets or patterns of spectral lines mean that the star has a different chemical composition.
虽然这些化学物质的简单存在并不一定表明存在健康风险，但典型的美国人身上携带这些化学物质的事实让琼和他的同事感到震惊。
While the simple presence of these chemicals does not necessarily indicate a health risk, the fact that typical Americans carry these chemicals at all shocked June and his fellow participants.
虽然这些化学物质的简单存在并不一定表明存在健康风险，但典型的美国人身上携带这些化学物质的事实让琼和他的同事感到震惊。
And while the simple presence of these chemicals does not necessarily indicate a health risk, the fact that typical Americans carry these chemicals at all shocked June and his fellow participants.
珀金刚入学的时候，皇家化学学院的院长是德国著名的化学家奥古斯特·威廉黑姆·霍夫曼。
At the time of Perkin's enrolment, the Royal College of Chemistry was headed by the noted German chemist August Wilhelm Hofmann.
那些演讲进一步激发了这位年轻化学家的热情，他后来继续进入了皇家化学学院，于1853年成功入学，当时他15岁。
Those speeches fired the young chemist's enthusiasm further, and he later went on to attend the Royal College of Chemistry, which he succeeded in entering in 1853, at the age of 15.
这两位化学家都非常有远见，他们对周期性的物理性质和化学性质进行分析，并在预示应该出现新元素的地方留下了空位。
Both chemists were sufficiently farsighted to leave gaps where their analyses of periodic physical and chemical properties indicated that new elements should be located.
化学家们确实发现了少量残留的三种可疑的化学物质，但他们指出这些化学物质在所有罐头食品中都会自然产生。
The chemists did find small amounts of the three remaining suspected chemicals but pointed out that these occur naturally in all canned foods.
有毒化学物质在我们的生活中随处可见，比如公共草地上用于杀虫的化学制剂，以及公共区域地板上用于清洁的化学物质。
Toxic chemicals are everywhere in our lives—insect-killing chemicals used on public grass areas, cleaning chemicals on the floors of public areas.
化学家和女教师坚持认为薄雾由几种化学物品构成。
The chemist and the mistress insist that the mist consists of several chemicals.
长期以来，健康和环保倡导者们一直在敦促美国政府部门加强对报告中提及的11种化学物品的使用管制，并呼吁对化学品的长期影响进行更多的研究。
Health and environmental advocates have long urged US government agencies to tighten the use of some of the 11 chemicals the report cites and called for more studies on their long-term effects.
化学过程是指化学物质聚集在一起产生其他化学物质，进而产生其他物质的过程。
A chemical process is what happens when chemicals come together to make other chemicals, and therefore other things.
在六十年代早期，程序化学习被看作是机械化学习过程的途径。
In the early sixties, programmed learning was looked on as the pathway to mechanize the learning process.
不同的原料由不同的化学物质构成，当你把它们放在一起加热烹煮时，其中的化学物质会变成新的化学物质，不同的成分会产生新的东西。
Your different ingredients are made of different chemicals, and when you put them together and make them hot and cook them, the chemicals change into new chemicals and the different ingredients make something new.
化学（chemistry）这个词来源于“化学的”（chemical），它是一种非常小的东西的例子，其他更大的东西是由它组成的。
The word chemistry comes from chemical, which is an example of one type of the very small things that other bigger things are made of.
当另一种植物获得化学物质时，它就会开始释放自己不同的化学物质。
When another plant gets the chemicals, it starts to give out its own, different chemicals.
他用来清洁仪器的化学物质与他在实验中使用的化学物质混合在一起，产生了一种亮紫色。
The chemicals he used to clean his instruments mixed with the chemicals he used in his experiment and produced a bright purple color.
我们可能很难看到日常的化学作用，但几乎你接触的所有东西都有一些化学物质。
It can be very hard to see the everyday chemistry at work, but nearly everything you touch has some chemicals in it.
化学激光器的特点是以释能化学反应提供能源。
Chemical laser is characteristically energized by an exoergic chemical reaction.
1981年底之前的商业化学品已列入《欧洲现有商业化学物质目录》。
Chemicals in commerce before the close of 1981 are listed in the EINECS.
化学自养生物和化学异养生物从无机氧化反应获得能量。
Chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
化学自养生物和化学异养生物从无机氧化反应获得能量。
Chemoautotrophs and chemoheterotrophs obtain energy from inorganic oxidation reactions.
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