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对环境监测布点采样中的QC/QA以及由采样引起的误差来源做了简要分析,并对监测采样过程中QC/QA的操作提出了一些设想。 相似文献
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DM Peter Lorenz Rainer Bollmann Georg Klaus Hinkel Marco Mächler Gabriele Siegert Gudrun Stamminger Jörg Wendisch Sabine Ziemer 《黑龙江环境通报》1991,11(11):819-825
The study of the fetal platelet count and size can, according to the literature, be used for the prenatal diagnosis of the Wiskott-Aldrich syndrome (WAS). So far, no affected fetuses have been identified by this method. All pregnancies in which this method had been applied to resulted, as correctly predicted, in the birth of normal children. Here we report on a familial case of WAS where the haematological parameters failed to reveal the affected second child. Hence we assume that the platelet count and size of platelets remain normal in fetuses with WAS to the gestational age of 22 weeks and cannot be used for prenatal diagnosis. 相似文献
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A. P. Lemes M. A. Soto-Oviedo W. R. Waldman L. H. Innocentini-Mei N. Durán 《Journal of Polymers and the Environment》2010,18(3):250-259
The effect of lignosulfonate on poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, was studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and
thermogravimetric analysis (TGA). The PHBV/lignosulfonate samples were prepared by melt mixing in an internal mixer. SEM showed
that PHBV/lignosulfonate samples present a cracked surface that is more intense in mixtures with high lignosulfonate proportions.
According to DSC, melting and glass transition temperatures of the PHBV matrix decrease with lignosulfonate addition. The
same effect was observed for melting enthalpies (ΔHm), which indicates a decrease of crystallinity. TGA showed that thermal stability of PHBV/lignosulfonate samples was shifted
to lower temperatures, which indicates the existence of an interaction between the thermal decomposition processes of PHBV
and lignosulfonate. 相似文献
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Using a sample of hospital employees this study addressed whether job satisfaction mediates the relationship between absenteeism predictors and absenteeism and how well absenteeism predictors explained different measures of absenteeism. The results suggest that job satisfaction is not a mediator and that the independent variables explain more variance in records‐based time lost than in self‐reported time lost or self‐reported absence frequency. Implications are discussed in terms of using job satisfaction as a mediator as well as the viability of alternative measures of absenteeism. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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The international community has compelling humanitarian, political, security and economic reasons to engage in rebuilding and strengthening health systems in fragile states. Improvements in health services and systems help to strengthen civil society and to restore legitimacy to governments. Effective engagement with fragile states to inform the design of health programmes and selection of interventions depends on donor coordination and an understanding of health system challenges. Planning requires consideration of allocation (services to be delivered), production (organisation of services), distribution (beneficiaries of services) and financing. The criteria for selecting interventions are: their impact on major health problems; effectiveness; the possibility of scale-up; equity; and sustainability. There are various options for financing and models of engagement, but support should always combine short-term relief with longer-term development. Stakeholders should aim not only to save lives and protect health but also to bolster nations' ability to deliver good-quality services in the long run. 相似文献
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Waldman P. Lucas F. S. Varrault G. Moulin L. Wurtzer S. 《Food and environmental virology》2020,12(2):118-129
Food and Environmental Virology - In urban rivers, many of which are used for drinking water production, viruses encounter a range of particulate, colloidal, and dissolved organic and inorganic... 相似文献