t*****a
发帖数: 40 | 1 请教一下各位：地质学上经常有δ13C (C13 Isotope Concentration)，请问这些术语是怎么定义的？用什么做参照标准?
哪里有相关介绍？
谢谢! |
f*****y
发帖数: 124 | 2 Wikipedia应该有
语是怎么定义的？用什么做参照标准?
【在 t*****a 的大作中提到】
: 请教一下各位：地质学上经常有δ13C (C13 Isotope Concentration)，请问这些术语是怎么定义的？用什么做参照标准?
: 哪里有相关介绍？
: 谢谢!
|
t*****a
发帖数: 40 | 3 没有
【在 f*****y 的大作中提到】
: Wikipedia应该有
:
: 语是怎么定义的？用什么做参照标准?
|
a***a
发帖数: 5 | 4
语是怎么定义的？用什么做参照标准?
The δ13C value is defined as the C-13 isotope concentration in a sample
relative to that in the standards. The standard is a particular limestone
from the Pee Dee Belemnite fossil (PDB). The value can be expressed by this
equation:
δ13C = [(13C/12C)sample-(13C/12C)PDB]/[(13C/12C)PDB]
You can find more detailed definition, derivation and explanations in any
stable isotope textbook.
【在 t*****a 的大作中提到】
: 请教一下各位：地质学上经常有δ13C (C13 Isotope Concentration)，请问这些术语是怎么定义的？用什么做参照标准?
: 哪里有相关介绍？
: 谢谢!
|
t*****a
发帖数: 40 | 5 Thank you very much!
I find out that sometime many other standards are used.
So how may I know which standard it was used in a paper? Is PDB the default
standard? Thanks!
【在 a***a 的大作中提到】
:
: 语是怎么定义的？用什么做参照标准?
: The δ13C value is defined as the C-13 isotope concentration in a sample
: relative to that in the standards. The standard is a particular limestone
: from the Pee Dee Belemnite fossil (PDB). The value can be expressed by this
: equation:
: δ13C = [(13C/12C)sample-(13C/12C)PDB]/[(13C/12C)PDB]
: You can find more detailed definition, derivation and explanations in any
: stable isotope textbook.
|
a***a
发帖数: 5 | 6 Generally, every lab produces its own standards for routine analyses. But
all the published data should have been calibrated relative to the
international standard (PDB for stable C isotopes).
default
【在 t*****a 的大作中提到】
: Thank you very much!
: I find out that sometime many other standards are used.
: So how may I know which standard it was used in a paper? Is PDB the default
: standard? Thanks!
|
