单位转换

✍ dations ◷ 2025-08-23 18:55:55 #单位转换
单位换算是指通过乘以换算系数实现不同计量单位间的等量换算。单位换算过程与用户具体情况和预期目的相关。可能受法令、合同、技术规格或其它出版物技术标准的限制。工程判断可能包括以下因素:某些从一个单位系统需要不增减精度地向另一个单位体系严密转换第一个量度。有时被称为“软转换”。它不涉及更改被计量的物理配置。与之相比,“硬转换”或“适应转换”可能不完全相等。它更改计量以适合在新体系内的有效数字与单位。它有时涉及项目的稍微不同的配置或尺寸替代。有时允许并使用标称值。此条目内不列出在公制单位国际单位制词头间的转换(例如:1 千克 = 1000 克, 1 毫克 = 0.001 克)。除非单位还有其他常见名称。各表内的单位以其英文字词的字母顺序列出,突出显示SI单位(基本单位或导出单位)。此条目给出列于索引内的各个物理量数值转换系数列表。各物理量不同单位的数值以相应的SI术语表示并显示(某些仅有历史意义)。Notes:A velocity consists of a speed combined with a direction; the speed part of the velocity takes units of speed.See also: Conversion between weight (force) and massOften, information entropy is measured in shannons, whereas the (discrete) storage space of digital devices is measured in bits. Thus, uncompressed redundant data occupy more than one bit of storage per shannon of information entropy. The multiples of a bit listed above are usually used with this meaning. Other times the bit is used as a measure of information entropy and is thus a synonym of shannon.The candela is the preferred nomenclature for the SI unit.Please note that although becquerel (Bq) and hertz (Hz) both ultimately refer to the same SI base unit (s−1), Hz is used only for periodic phenomena, and Bq is only used for stochastic processes associated with radioactivity.The roentgen is not an SI unit and the NIST strongly discourages its continued use.Although the definitions for sievert (Sv) and gray (Gy) would seem to indicate that they measure the same quantities, this is not the case. The effect of receiving a certain dose of radiation (given as Gy) is variable and depends on many factors, thus a new unit was needed to denote the biological effectiveness of that dose on the body; this is known as the equivalent dose and is shown in Sv. The general relationship between absorbed dose and equivalent dose can be represented aswhere H is the equivalent dose, D is the absorbed dose, and Q is a dimensionless quality factor. Thus, for any quantity of D measured in Gy, the numerical value for H measured in Sv may be different.Home and office computers come with converters in bundled spreadsheet applications or can access free converters via the Internet. Units and measurements can be easily converted using these tools, but only if the units are explicitly defined and the conversion is compatible (e.g., cmHg to kPa).When a measure is converted to another unit in a fiction work like a novel or film, the value often loses meaning (as in numerology) or gets too many significant digits ("40 miles" turns into "64 km"). For this reason, authors sometimes choose numbers that can be converted easily. Most notably, distances measured in miles often begin with 3 or 5, so the value ghjcfugffyhfdfgjvcgconverted to km also has one significant digit (5 or 8).

相关

  • NSAIDs非甾体消炎药(英语:Non-Steroidal Anti-Inflammatory Drug,縮寫作NSAID),也译作非类固醇抗炎药,是一类具有解热镇痛效果的药物,在施用较高剂量时也具有消炎作用。“非甾体”一词用
  • 草菇Volvaria volvaceaAgaricus volvaceusAmanita virgataVaginata virgata蕈伞圆锥状草菇(学名:Volvariella volvacea)是食用菌的一个种类,因为生长在稻草上而得名,又名兰花菇、美味
  • 卡尔洪县卡尔霍恩县 (Calhoun County, Georgia)是美国乔治亚州西南部的一个县。面积734平方公里。根据美国2000年人口普查估计,共有人口6,320人。县治摩根 (Morgan)。成立于1854年2月
  • 荷兰皇家陆军荷兰皇家陆军(荷兰语:Koninklijke Landmacht)是荷兰军队的地面部队。荷兰陆军成立于1814年1月9日,但它的起源可追溯至1572年。荷兰共和国在17和18世纪初开始训练这支军队,并参与8
  • Sbsub2/subOsub5/sub五氧化二锑(Sb2O5)是一种锑和氧形成的无机化合物。它通常以水合物Sb2O5·nH2O形式存在,没有确切证据表明制得了无水五氧化二锑。该化合物中锑的氧化态是+5。五氧化二锑的结构与
  • 奇经八脉奇经八脉,中医学概念,指“别道奇行”的经脉,有别于“十二正经”(十二经脉),八脉包括督脉、任脉、冲脉、带脉、阴维脉、阳维脉、阴
  • 凯文·林奇凯文·林奇(英语:Kevin Andrew Lynch,1918年1月7日-1984年4月25日)是一位美国城市规划师和作家,以其在城市环境的感知形式方面的工作而闻名,并且是心理地图(英语:Mental mapping)的早
  • 子宫旁组织宫旁组织(英语:parametrium),是一类纤维组织,包括宫颈旁和宫体旁组织两部分,分别位于宫颈两侧和子宫体下部周围,二者无明显分界。宫旁组织主要由含血管丰富的结缔组织构成,其中宫颈
  • 冕环冕环形成于太阳日冕低处的基础结构和过渡区,这些高耸且优雅的结构是太阳内部的磁通量直接被扭曲的结果。冕环的密度直接与太阳周期相关联,这也是冕环的足点经常可以看见太阳黑
  • 普卢默斯普卢默斯国家森林(英语:Plumas National Forest)是一座占地1,146,000英亩(464,000公顷)的美国国家森林,位于加利福尼亚州北部的内华达山脉,最近的城市是昆西。