Dna damages caused by so2 and lead acetate were studied with the single cell microgel electrophoresis technique ( or comet assay ) in order to confirm the damaging degree of lead ( as an important component of atmosphere particle matter ) on dna from male mice exposed to so2. the migrating distances of dna of brain, lung, spleen and kidney cells of mice increased significantly, compared to the control group under conditions of single and combined poisoning of so2 ( 42mg / m3 ) and lead acetate ( 0. 2 % ), and lead could strengthen dna damage degree by so2 in nuclear dna of brain, kidney, spleen cells. damaging degree of so2 on nuclear dna of lung cell of mice was more severe than that of lead
為了明確大氣顆粒物中的重要組分? ?鉛在二氧化硫所致dna損傷中的作用程度，利用單細胞凝膠電泳技術（ singlecellgelelectrophoresis ， scge ，或稱
彗星實驗， cometassay ）研究了鉛與二氧化硫的聯合污染，結果表明在42mg m ~ 3so _ 2和0 . 2醋酸摘要一abstract鉛單獨及聯合染毒條件下，小鼠腦、肺、腎、脾細胞dna遷移距離均比對照顯著增加;鉛加劇了50 :對腦、腎、脾細胞
核dna的損傷程度; 50 :對肺細胞
核dna的損傷程度要比鉛的損傷大，小鼠肺細胞
核dna遷移距離在50 :和醋酸鉛聯合作用組與醋酸鉛單獨作用組間有極顯著性差異（ p < 0 . 01 ） ，而與502單獨作用組間沒有顯著性差異。
Standard guide for determining dna single - strand damage in eukaryotic cells using the comet assay
用
彗星分析法測定真
核細胞中dna單線損傷的標準指南
Evaluating genotoxicity of water quality in lanzhou section of the yellow river using micronucleus test and comet assay
利用微
核試驗和
彗星電泳試驗評價黃河蘭州段水質致遺傳毒性作用
Study on monitoring genotoxicant pollution in surface water of yangzhong city using micronucleus test and comet assay
應用蠶豆根尖微
核技術和
彗星試驗監測揚中地表水遺傳毒物污染的研究
This at least accounts for the fact that a particular group of meteoroids shares with its parent comet more or less the same orbit, which can remain relatively unchanged over eons. an immediate consequence is that our earth makes periodic rendezvous with this meteoroid swarm, thereby culminating in a regular display of these celestial fireworks. to name a few, we have the lyrids in april and the geminids in december
流星雨的成因是地球遇上了一群密集的流星體，一般相信，流星群是由周期性
彗星分解出來的物質或由瓦解了的
彗核所形成，所以流星群和其母體
彗星有大致相同的軌道，由於流星群的軌道頗為固定，所以地球會周期性地穿越這些流星群，形成固定出現的流星雨，例如四月天琴座流星雨十二月雙子座流星雨等。
Historically, these visitors to the inner solar system provided a dazzling sight - brilliant, with long, narrow tails visible even in twilight
歷史上，這些內太陽系的過客曾經向人們展示了驚艷的景觀? ?細長的
彗尾與明亮的
彗核輝映著黃昏的天空。
The head of the comet remains quite bright and easily visible to even city observers without any optical aide
彗星的
彗核仍然非常明亮，因此不需藉助任何設備，用肉眼就可以看到。
A comet consists of a tiny nucleus with diameter less than 10km. the nucleus is made up of frozen gases and dust
在
彗星中心是一顆由凝固了的氣體和塵埃組成直徑小於10公里的細小
彗核。
Owing to the comet s own movement, the head or the nucleus of the comet should be followed as the target for best result
彗星有其本身的移動方向與速度，因此要拍攝清晰的
彗星照片，就必須以
彗頭或
彗核作為追縱對象。
Spacecraft giotto s encounter with comet halley provided the first ever opportunity to take images of a comet nucleus when comet halley returned in 1986
1986年哈雷
彗星回歸時，歐洲太空總署發射的太空船喬圖號成功拍攝到哈雷
彗星的
彗核。
Fascinated sky enthusiasts in the earth ' s northern hemisphere were treated to an instantly visible comet head and a faint elongated tail near sunrise and sunset
北半球的眾多天文迷在黃昏和清晨爭睹這顆擁有肉眼可見的
彗核以及細長的
彗尾的
彗星。
Forget nuclear warheads to stop a crash with a comet that could have cataclysmic effects such as the one that is believed to have triggered the demise of the dinosaurs, hermann burchard of oklahoma state university told new scientist magazine
俄克拉荷馬州立大學的赫爾曼-伯恰德對新科學家雜志說，別想用核彈頭去阻止同彗星的碰撞，那樣做的後果會跟據信使恐龍絕滅的那次災難差不多。
