natural adj. 1.自然界的;关于自然界的。 2.天然的;未开垦的;野生的。 3.固有的,生来的,天赋的(opp. acquired);出乎本性的。 4.自然的,不加修饰的,不加做作的。 5.本来的;(论理上或人情上)当然的,不勉强的,常态的;普通的,平常的。 6.逼真的。 7.私生的,庶出的。 8.【音乐】本位的;标明本位号的。 9.【数学】自然数的;真数的。 the natural day 自然日〔由日出至日没〕。 the natural forces 自然力。 natural phenomena 自然现象。 the natural world 自然界。 the natural year 自然年,太阳年。 natural gas 天然气。 natural resources 天然资源。 It is quite natural that you (should) succeed [for you to succeed]. 你的成功是很自然的。 Speaking comes natural to him. 他的演说流畅而自然。 natural disposition 天性,本性。 a natural gift 天资,天禀。 natural poet 天生的诗人。 natural vibration 固有振动。 natural sine 正弦真数。 one's natural life 寿命,寿限。 natural wages 实物工资。 a natural sign 【音乐】本位记号。 n. 1.(生来的)白痴。 2.【音乐】(风琴等的)白键;本位音;本位号(NE224)。 3.(二十一点牌戏)一分牌就赢的两张牌。 4.〔美俚〕未曾受过训练而表演得意外出色的人,意外出色的表演;〔口语〕对某方面(似乎)有天生特长的人。 5.〔美口〕可望立即成功的事物。
Alpha particles are positively charged helium nuclei obtained from natural radioactive decay . 粒子是从天然放射性蜕变得到的带正电的氦核。
Natural radioactive background 天然放射性本底
It is now attributed to certain iron constituents in connection with natural radioactive radiation 它也被视为是主教的宝石,因此他们时常佩带紫水晶戒指。
His work was done before the discovery of radioactivity and the understanding that natural radioactive decay provides a source of heat to the earth 他的工作是做了,才发现放射性和谅解,即天然放射性衰变提供热源,以地球。
Trace amounts of natural radioactive materials , such as uranium , thorium and potassium with half - lives of up to one billion years , exist in soil 泥土中含有微量的铀、钍和钾等天然放射性物质,这些放射性同位素的半衰期可以长达10亿年。
Trace amounts of natural radioactive materials , such as uranium , thorium and potassium with half - lives of up to one billion years , exist in soil 泥土中含有微量的铀、钍和钾等天然放射性物质,这些放射性同位素的半衰期可以长达10亿年。
Although almost all this material , which has a 24 , 000 - year half - life , has since disappeared ( primarily through natural radioactive decay ) , some of the plutonium itself underwent fission , as attested by the presence of its characteristic fission products 这些物质半衰期为2万4000年,几乎已经全部消失(主要是经由自然的放射衰变过程) ,而且部份的钸本身又经过核分裂,这可由其核分裂产物为证。
It is important that study gamma - ray spectrometry of field rock and soil in the earth ' s crust . its energies range between 30kev and 3000kev , where there is much information of natural radioactive nuclides , such as uranium , thorium , potassium , and information of artificial radioactive nuclides , such as cesium , americium , cobalt , and information of the results in interaction between gamma - ray and earth ' s crust 研究表明:野外地面射线能谱测量主要研究地壳岩石土壤中产生的能量约为30kev 3000kev的射线,这里面包含着铀、钍、钾等天然放射性核素信息,核工程活动产生的大量人工放射性核素信息以及射线与地壳相互作用产生的相关信息。
Abstract : under the base of investigation and research on natural radioactive nuclein in coal of yili area , combining with the distributing characteristic and law of radioactive nuclein in coal of area and residents ' customer of using coal in yili area , the article raises decrement , resources , harmless and prevention and control measure of whole course managing rule with having a definite object in view and put foward a feasible plan and way for economie developmant of yili area , resonable development and utilization of coal resources , preventing from pollution because of mining and utilizing coal and further protecting people ' s health 文摘:在对伊犁地区煤中天然放射性核素调查研究的基础上,结合伊犁地区煤中放射性核素分布的特点、规律以及伊犁地区居民的用煤习惯,有的放矢的提出了减量化、资源化、无害化以及全过程管理原则的防治措施,为伊犁地区的经济发展,煤炭资源的合理开发和利用,防止因煤炭的开采利用而造成的污染,建设性的提出了切实可行的方案和途径。
Even without these man made sources of radiation , exposed to natural background radiation . the rocks and soil of the earth s crust contain variable amounts of natural radioactive elements such as uranium and thorium . this varies with geography - for example the hottest places in britain are cornwall and around aberdeen 就算排除人为辐射,人类会在天然环境中接触到本底辐射,如地球外壳的岩石和泥土含有份量不同的辐射元素如铀和钍,而份量视乎地理位置,如英国的康瓦尔和阿伯丁郡最为热点。