|
1. |
Radioisotope detection and dating with accelerators |
|
Eos, Transactions American Geophysical Union,
Volume 62,
Issue 11,
1981,
Page 105-106
A. E. Litherland,
J. C. Rucklidge,
Preview
|
PDF (1412KB)
|
|
摘要:
Recent developments in mass spectrometry have made possible the direct detection of many naturally occurring long‐lived radioisotopes. Radioactive atoms are present at such low concentrations that the sensitivity of the mass spectrometry has to be increased to detect parts per quadrillion (1015) in a sample. This sensitivity has been achieved, and some of the results taken at Rochester by the Rochester (University), Toronto (University), General Ionex (Corporation) collaboration are listed in the table. All the radioactive isotopes listed in the table are of importance in geochronology, and for14C and36C1, sensitivities better than parts per quadrillion (1015) have already been reached. Early work on the stable isotopes of platinum has already reached below parts per billion (109
ISSN:0002-8606
DOI:10.1029/EO062i011p00105-01
年代:1981
数据来源: WILEY
|
2. |
Shuttle project for students |
|
Eos, Transactions American Geophysical Union,
Volume 62,
Issue 11,
1981,
Page 107-107
Anonymous,
Preview
|
PDF (147KB)
|
|
摘要:
Selection of 200 semifinalists has begun for the first national Space Shuttle Student Involvement Project, a joint effort of NASA and the National Science Teachers Association. The semi finalists are being selected from 1500 entries.Objective of the project is to stimulate study of science and technology in grades 9 through 12. Students compete to develop payload experiments suitable for flight aboard the shuttle. The 1500 entries, grouped into 10 geographic areas, are being reviewed by interdisciplinary teams of teachers, scientists, and engineers. Twenty students from each region will be selected. Ten finalists will then be chosen on their scientific or engineering merit. The 10 national winners and their teachers will attend a special education conference late this summer at the Kennedy Space Center in Florida.
ISSN:0002-8606
DOI:10.1029/EO062i011p00107-01
年代:1981
数据来源: WILEY
|
|