科普英语的内容?要通通英语的..要多 3篇 有知道发给我哦 不然关闭了
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科普英语的内容?要通通英语的..要多 3篇 有知道发给我哦 不然关闭了
科普英语的内容?
要通通英语的..要多 3篇
有知道发给我哦 不然关闭了
科普英语的内容?要通通英语的..要多 3篇 有知道发给我哦 不然关闭了
暗银河系的发现及其科学意义
In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers. Possibly as numerous as conventional galaxies, these galaxies have the same general shape and even the same approximate number of stars as a common type of conventional galaxy, the spiral, but tend to be much larger. Because these galaxies ’mass is spread out over larger areas, they have far fewer stars per unit volume than do conventional galaxies. Apparently these low-surface-brightness galaxies, as they are called, take much longer than conventional galaxies to condense their primordial gas and convert it to stars—that is, they evolve much more slowly.
These galaxies may constitute an answer to the long-standing puzzle of the missing
baryonic mass in the universe. Baryons—subatomic particles亚原子粒子 that are generally protons or neutrons—are the source of stellar, and therefore galactic, luminosity, and so their numbers can be estimated based on how luminous galaxies are. However, the amount of helium in the universe, as measured by spectroscopy光谱学, suggests that there are far more baryons in the universe than estimates based on galactic luminosity indicate. Astronomers have long speculated that the missing baryonic mass might eventually
be discovered in intergalactic space星系际的空间 or as some large population of galaxies that are difficult to detect.
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另类海豹哺乳方式与众不同
Until recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species. However, recent studies on
harbor seals, a phocids species, found that lactating females commenced foraging
approximately 6 days after giving birth and on average made 7 foraging trips during the remainder of their 24-day lactation period.
The maternal strategy evolved by harbor seals may have to do with their small size and the large proportion of their fat stores depleted in lactation. Harbor seals are small compared with other phocids species such as grey seals, all of which are known to fast for the entire lactation period. Studies show that mother seals of these species use respectively 84 percent, 58 percent, and 33 percent of their fat stores during lactation. By comparison, harbor seals use 80 percent of their fat stores in just the first 19 days of lactation, even though they occasionally feed during this period. Since such a large proportion of their fat stores is exhausted despite feeding, mother harbor seals clearly cannot support all of lactation using only energy stored before giving birth. Though smaller
than many other phocids, harbor seals are similar in size to most otariids. In addition,
there is already some evidence suggesting that the ringed seal, a phocids species that
is similar in size to the harbor seal, may also use a maternal foraging strategy.
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pheromones是什么东东,是不是该划为odorant
There is no consensus among researchers regarding what qualifies a substance as a pheromone. While most agree on a basic definition of pheromones as chemicals released by one individual of a species which, when detected by another individual of the same species, elicit a specific behavioral or physiological response, some researchers also specify that the response to pheromones must be unconscious. In addition, the distinction
between pheromones and odorants—chemicals that are consciously detected as odors---can be blurry, and some researchers classify pheromones as atype of odorant. Evidence that pheromone responses may not involve conscious odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For example,
garter snakes detect a chemical signal from earthworms—one of their favorite foods—via
the VNO, and they use this signal to track their prey.
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吃糖一向被视为肥胖者的大忌,,除此以外,一般读者可能还知道吃糖与蛀牙、与某些心血管疾病的关系。可你是否想到过吃糖与人的衰老也有关系呢?本文则报道了这方面的最新研究成果,读后令人大长见识。
Rats that eat high levels of a natural sugar known as fructose seem to age faster than other rats----...
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吃糖一向被视为肥胖者的大忌,,除此以外,一般读者可能还知道吃糖与蛀牙、与某些心血管疾病的关系。可你是否想到过吃糖与人的衰老也有关系呢?本文则报道了这方面的最新研究成果,读后令人大长见识。
Rats that eat high levels of a natural sugar known as fructose seem to age faster than other rats----and the same could be true for people who eat too much sweet junk food, Israeli researchers said Monday.
以色列的研究人员星期一说,大量摄取一种叫做果糖的天然糖的老鼠,似乎比其他老鼠衰老的更快。对甜食吃得太多的人来说,情况也可能会是如此。
Fructose, found naturally in honey and fruit, is used widely in foods ranging from soft drinks to yogurt. But while its sweet taste is popular, the sugar could cause wrinkles and heal the problems, the researchers said. Dr. Moshe Werman and Boaz Levi of the Technion- Israel Institute of Technology fed large amounts of fructose to laboratory rats. Writing in the Journal of Nutrition, they said the fructose-fed rats showed changes n the collagen of their skin and bones.
自然存在于蜂蜜和水果中的果糖,被广泛用于从饮料到酸奶的各种食品中。研究人员说,尽管它的甜味很受欢迎,这种糖却能使皮肤起皱纹并影响身体健康。以色列科学技术研究所的摩西- 沃曼和波阿兹-利位博士喂给实验鼠大量果糖。他们在《营养学杂志》上发表文章说,那些吃了果糖的老鼠的皮肤和骨质中的胶原蛋白发生了变化。
Collagen, a fibrous protein found in connective tissue, bone and cartilage, basically holds the body together. The loss of collagen is what causes sagging and deep wrinkles in older people.
胶原蛋白是存在于结缔组织、骨质和软骨中的纤维蛋白质,它的基本作用是将人体各组织结合在一起。胶原蛋白的丧失是导致老年人皮肤松弛和深度皱纹的原因。
The process affected, Werman's team said, is known as "cross linking". "Too much cross-linking reduces elasticity and makes the skin stiff and rigid, and these are the conditions that encourage wrinkled skin," Werman said in a statement. He said the same could be true of people, although this has not been shown. "Americans are eating more and more processed foods such as carbonated drinks, baked goods, canned fruits, jams and dairy products that contain fructose," Werman said. Other studies have shown that high fructose intake can affect how the body handles glucose and increases insulin resistance---- which can both be important measures of the tendency toward diabetes.
沃曼领导的研究小组把胶原蛋白的丧失引起的生理变化称作"交叉相联"。沃曼在一次报告中说:"太多的'交叉相联'就会使皮肤降低弹性,发生硬化,这是导致皮肤起皱纹的原因。"他说,人也可能是如此,尽管还没有证据证明这一点。他又说:"美国人摄取的加工食品越来越多,例如碳酸饮料、烘烤食品、罐装水果、果酱和乳制品,而这些食品都含有果糖。"其他的一些研究已经表明,大量摄取果糖会影响人体对葡萄糖的代谢和增强对胰岛素的抵抗力,而这两者是判断患糖尿病可能性的重要指标。
The rats Werman worked with were fed much more than the average adult person might eat in a day, which is standard in such experiments. The rats were fed 12.5 grams of fructose per kg (2.2 pounds) of weight every day for a year. To compare, a person weighing 154 pounds (70kg) who drinks a quart (liter) of cola consumes about 60 grams of fructose, or 0.8 grams per kg of body weight.
沃曼喂养的老鼠摄取的果糖比普通成人每天可能摄取的果糖多的多,这在此类实验中是符合标准的。在一年的时间里,这些老鼠每天按每千克(2.2磅)体重12.5克的标准摄取果糖。与此相比,一个体重154磅(70千克)的人,喝一夸脱(升)的可乐,大约摄取了60克的果糖,或者说每千克体重摄取0.8克的果糖
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〖内容简介〗-趣味科普英语学习指导(初级):含磁带
本书是与《趣味科普英语》配套的学习指导用书,具有以下特点:1.增补了新的科普知识点,从一定程度上弥补了《趣味科普英语》由于篇幅所限而带来的知识点不够全面的不足。2.对《趣味科普英语》一书所列举的创意题给出了答案要点,突出了中小学生用英语表达科技创意的关键知识。3.将《趣味科普英语》一书中的课文翻译成了中文,有助于加深对原文的理解。4.配...
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〖内容简介〗-趣味科普英语学习指导(初级):含磁带
本书是与《趣味科普英语》配套的学习指导用书,具有以下特点:1.增补了新的科普知识点,从一定程度上弥补了《趣味科普英语》由于篇幅所限而带来的知识点不够全面的不足。2.对《趣味科普英语》一书所列举的创意题给出了答案要点,突出了中小学生用英语表达科技创意的关键知识。3.将《趣味科普英语》一书中的课文翻译成了中文,有助于加深对原文的理解。4.配有录音磁带,让中小学生在阅读英语科普作品的同时,在听力上有所提高和突破。5.适合学生自学,也可作为家长和教师辅导学生之用
http://www.sciencenewsforkids.com/
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Until recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped fa...
全部展开
Until recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of Until recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast,
use a fasting strategy in which mother phocids, having accumulated large energy
odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO),to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of
odorants triggers sensations of smell. But while the VNO does process many animal
pheromone signals, not all animal pheromones work through the VNO. Conversely,
not all chemical signals transmitted via the VNO quality as pheromones. For exampleUntil recently, zoologists believed that all species of phocids (true seals), a pinnipped family, use a different maternal strategy than do otariids (fur seals and
sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at b