helium 音标拼音: [h'iliəm]
n . 氦
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:
复制到剪贴板
英文字典中文字典相关资料:
Social Security Customer Service - AARP The Social Security Administration (SSA) offers customer service online, by phone and at field offices nationwide You can conduct most routine business, including applying for benefits and filing appeals, at the Social Security website or by calling the SSA’s national customer service line (800-772-1213)
How to Set Up an Online Social Security Account - AARP As the Social Security Administration stops sending paper account statements you should open a My Social Security online account to manage benefits
Social Security Glossary of Frequently Used Terms - AARP A list and description of frequently used Social Security terms and acronyms to help applicants and beneficiaries understand policies and benefits
Understanding Social Security Retirement Benefits - AARP The basics of social security retirement benefits, including how benefits work, how payments are calculated and awarded, and what you need to apply
Social Security Drops Changes to Disability Eligibility - AARP Social Security relies on the surplus in its two trust funds, one for retirement and survivor benefits and the other for disability benefits, to meet its annual payment obligations
Social Security - News, Tools, and Resources - AARP Stay informed with AARP's latest updates on Social Security Learn how to apply, maximize your benefits, and navigate disability qualifications
Social Security Sets 2026 COLA Increase at 2. 8% - AARP The Social Security Administration set its latest COLA increase Learn how the cost-of-living increase could boost your 2026 Social Security payments
How To Get A Verification Letter From Social Security - AARP A benefit verification letter spells out your Social Security benefits, Supplemental Security Income or Medicare coverage Check out the key steps to obtaining the letter
How You Can Verify Your Identity with Social Security - AARP Social Security offers multiple ways to verify ID Here’s what to expect when you apply for retirement benefits by phone, in person or online
How to Get a Replacement SSA-1099 Tax Form - AARP An SSA-1099, also known as a Social Security Benefit Statement, details income from Social Security payments The Social Security Administration mails SSA-1099s every January to U S citizens and residents who received benefits the previous year so they can include the information on their tax returns