Preparation of Yangtze River Delta Sediment Reference Materials
Bibliographic record
Abstract
More than 10 harbour and estuarine sediment reference materials have been developed in the United States, Canada and other countries, but most of them focus on organic pollutants and radionuclide, and lack certified values. Three sediment reference materials of the Yellow river delta have been prepared in China in 2007. In order to meet the needs of offshore marine sediment geochemical surveys and resource exploration, two sediment standard materials of the Yangtze river delta were prepared according to ISO guidelines and technical standards for reference standards at the national level. Two samples were collected according to different particle sizes, and were dried and ball milled to 200 mesh. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) were used to test the homogeneity. Results show that the F values for the variance test were less than the threshold, which indicates good homogeneity. X-ray Fluorescence Spectroscopy was used for a four-time stability test in two years. No statistically significant changes were observed and the stability of the samples was good. A total of 13 accurate and reliable analytical methods were used in 12 technologically significant laboratories to finalize the contents of 53 elements. The major elements show gradient distribution with 16.42% and 11.48% of Al2O3. These two reference materials have multiple elements with determined values by accurate and reliable methods, which can provide quality assurance for the analysis and testing during geological and environmental surveys in the Delta region.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.007 | 0.004 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".