全文获取类型
收费全文 | 58篇 |
免费 | 0篇 |
专业分类
化学 | 29篇 |
物理学 | 29篇 |
出版年
2022年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1986年 | 8篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1942年 | 1篇 |
排序方式: 共有58条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Proper epidemiological, risk assessment and exposure analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related halogenated aromatic hydrocarbons (HAHs) requires accurate measurements of these chemicals both in the species of interest and in various exposure matrices (i.e. biological, environmental, food and feed). High-resolution instrumental analysis techniques are established for these chemicals, however, these procedures are very costly and time-consuming and as such, they are impractical for large scale sampling studies (i.e. for epidemiological studies and assessment of areas with widespread contamination). Accordingly, numerous bioanalytical methods have been developed for the detection of these chemicals in extracts from a variety of matrices, the majority of which take advantage of the ability of these chemicals to activate the aromatic hydrocarbon receptor (AhR) and the AhR signal transduction pathway. Here we review the currently available in vitro AhR-based cell bioassay systems with a focus on recent recombinant reporter gene cell lines that have been developed for detection and relative quantitation of TCDD and related HAHs. Comparison of the relative sensitivities of the various cell bioassays and examples of their use in screening and analysis of environmental, biological, and food and feed samples are presented. Currently available experimental results and validation studies demonstrate the utility of these cell bioassay systems to provide a relatively rapid, accurate, and cost effective screening approach for the detection of TCDD and related HAHs in a variety of environmental, biological, food and feed samples. The availability of these cell bioassay systems will not only facilitate the large scale sampling studies needed for accurate assessment of contamination and exposure to these environmental chemicals, but they provide avenues for the identification of novel classes of TCDD-like chemicals. 相似文献
5.
C. Boekema A. B. Denison D. W. Cooke R. H. Heffner R. L. Hutson M. Leon M. E. Schillaci 《Hyperfine Interactions》1983,15(1-4):529-532
Muon Spin Rotation (SR) results for magnetite (Fe3O4) are analyzed and discussed. At room temperature, a SR signal is observed due to the presence of an internal magnetic field (Bint) at the muon site. External transverse field measurements show that Bint is parallel to the magnetic spin direction, the <111> direction in zero applied field. Calculations of the hyperfine field to pinpoint muon stopping sites in magnetite show that the local field contains supertransfer (covalent) and dipolar field contributions. The implanted muons appear to stop at sites structurally similar to those reported for hematite (-Fe3O4), where muon-oxygen bond formation was strongly indicated.Research partially supported by US Department of Energy 相似文献
6.
C. Boekema V. A. M. Brabers R. L. Lichti A. B. Denison D. W. Cooke R. H. Heffner R. L. Hutson M. E. Schillaci D. E. Maclaughlin S. A. Dodds 《Hyperfine Interactions》1986,31(1-4):369-374
Zero-field longitudinal muon-spin-relaxation (μSR) experiments have been performed on single crystals of pseudo-brookite (Fe2−xTil+x
O
5; x=0.25), an anisotropic spin-glass system. The spinglass temperature (Tg) is determined to be 44.0±0.5K. Above Tg, a distinct
exponential muon-spin-relaxation rate (λ) is observed, while below Tg a square-root exponential decay is seen, indicating
fast spin fluctuations in the ‘frozen’ state. Near 8K, a maximum in λ is observed, which is due to transverse spin ordering
at these low temperatures. Even near Tg, λ is very low (<1 μs−1), likely due to a well-defined muon-oxygen state in the single crystals. The sharp λ-increase (with decreasing temperatures)
above Tg allows a comparison between spinfreezing models like the Vogel-Fulcher law and a power law. The results of these
initial measurements indicate that dynamic (and static) magnetism in oxide spin glasses can be directly monitored through
μSR. 相似文献
7.
8.
K. C. B. Chan R. L. Lichti C. Boekema A. B. Denison D. W. Cooke M. E. Schillaci 《Hyperfine Interactions》1986,31(1-4):481-486
A muon site search using calculated internal fields has been performed for V2O3, where purely dipolar fields allow a site determination free from covalent complications. The obtained sites are a subset
of the Rodriguez and Bates sites found in α-Fe2O3 and indicate muon oxygen bond formation. The sites missing at low temperatures are consistent with the vanadium pairing mechanism
for the metal-to-insulator (corundum-to-monoclinic) phase transition. 相似文献
9.
10.