英文字典中文字典


英文字典中文字典51ZiDian.com



中文字典辞典   英文字典 a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p   q   r   s   t   u   v   w   x   y   z       







请输入英文单字,中文词皆可:

helium    音标拼音: [h'iliəm]
n. 氦



helium
n 1: a very light colorless element that is one of the six inert
gasses; the most difficult gas to liquefy; occurs in
economically extractable amounts in certain natural gases
(as those found in Texas and Kansas) [synonym: {helium}, {He},
{atomic number 2}]

Noble \No"ble\, a. [Compar. {Nobler}; superl. {Noblest}.] [F.
noble, fr. L. nobilis that can be or is known, well known,
famous, highborn, noble, fr. noscere to know. See {know}.]
1. Possessing eminence, elevation, dignity, etc.; above
whatever is low, mean, degrading, or dishonorable;
magnanimous; as, a noble nature or action; a noble heart.
[1913 Webster]

Statues, with winding ivy crowned, belong
To nobler poets for a nobler song. --Dryden.
[1913 Webster]

2. Grand; stately; magnificent; splendid; as, a noble
edifice.
[1913 Webster]

3. Of exalted rank; of or pertaining to the nobility;
distinguished from the masses by birth, station, or title;
highborn; as, noble blood; a noble personage.
[1913 Webster]

Note: Noble is used in the formation of self-explaining
compounds; as, noble-born, noble-hearted, noble-minded.
[1913 Webster]

{Noble gas} (Chem.), a gaseous element belonging to group
VIII of the periodic table of elements, not combining with
other elements under normal reaction conditions;
specifically, {helium}, {neon}, {argon}, {krypton},
{xenon}, or {radon}; also called {inert gas}.

{Noble metals} (Chem.), silver, gold, and platinum; -- so
called from their resistance to oxidation by air and to
dissolution by acids. Copper, mercury, aluminium,
palladium, rhodium, iridium, and osmium are sometimes
included.
[1913 Webster]

Syn: Honorable; worthy; dignified; elevated; exalted;
superior; sublime; great; eminent; illustrious;
renowned; stately; splendid; magnificent; grand;
magnanimous; generous; liberal; free.
[1913 Webster]


Helium \He"li*um\ (h[=e]"l[i^]*[u^]m), n. [NL., fr. Gr. "h`lios
the sun.] (Chem.)
An inert, monoatomic, gaseous element occurring in the
atmosphere of the sun and stars, and in small quantities in
the earth's atmosphere, in several minerals and in certain
mineral waters. It is obtained from natural gas in industrial
quantities. Symbol, He; atomic number 2; at. wt., 4.0026
(C=12.011). Helium was first detected spectroscopically in
the sun by Lockyer in 1868; it was first prepared by Ramsay
in 1895. Helium has a density of 1.98 compared with hydrogen,
and is more difficult to liquefy than the latter. Chemically,
it is an inert noble gas, belonging to the argon group, and
cannot be made to form compounds. The helium nucleus is the
charged particle which constitutes alpha rays, and helium is
therefore formed as a decomposition product of certain
radioactive substances such as radium. The normal helium
nucleus has two protons and two neutrons, but an isotope with
only one neutron is also observed in atmospheric helium at an
abundance of 0.013 %. Liquid helium has a boiling point of
-268.9[deg] C at atmospheric pressure, and is used for
maintaining very low temperatures, both in laboratory
experimentation and in commercial applications to maintain
superconductivity in low-temperature superconducting devices.
Gaseous helium at normal temperatures is used for buoyancy in
blimps, dirigibles, and high-altitude balloons, and also for
amusement in party balloons.
[Webster 1913 Suppl. PJC]



安装中文字典英文字典查询工具!


中文字典英文字典工具:
选择颜色:
输入中英文单字

































































英文字典中文字典相关资料:


  • Calculate Your BMI - Standard BMI Calculator
    Calculate Your Body Mass Index Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women
  • BMI Calculator
    Free Body Mass Index calculator gives out the BMI value and categorizes BMI based on provided information from WHO and CDC for both adults and children
  • Adult BMI Calculator | BMI | CDC
    This calculator provides BMI and the corresponding BMI category for adults 20 and older For children and teens 2 through 19 years, use the BMI Calculator for Children and Teens
  • Calculate your body mass index (BMI) - NHS
    Calculate your body mass index (BMI) Check an adult's or child's BMI to find out if they're a healthy weight It's important to use the right calculator for adults (aged 18 and over) or children and teenagers (aged between 2 and 17)
  • Body Mass Index (BMI) Calculator - Diabetes Canada
    BMI is a simple calculation that uses a person’s height and weight to designate a classification The formula is BMI = kg m 2; kg is a person’s weight in kilograms and m 2 is height in metres squared
  • BMI Calculator Body Mass Index
    BMI Calculator for men, women and children finds Body Mass Index given weight and height BMI is a ratio of weight and height that indicates health risk due to overweight conditions
  • BMI Calculator (Body Mass Index and BSA) Calculator
    Enter the patient’s height and weight in the BMI Calculator to calculate the Body Mass Index based on the estimated body fat
  • What’s your body mass index (BMI)? - Heart Foundation
    BMI is calculated using your weight and height (your weight divided by your height squared) Along with several other factors, like your blood pressure and cholesterol, BMI can help estimate your risk of a heart attack or stroke
  • BMI Calculator - Calculate your Body Mass index
    Submit your height and weight to calculate your BMI Complete optional fields below to learn more about your waist size, health risks, and steps to reach your weight goals
  • BMI Calculator - BMI Calculator
    BMI calculator online: Get your Body Mass Index results fast Check if you're underweight, normal, overweight, or obese It's free!





中文字典-英文字典  2005-2009