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排序方式: 共有599条查询结果,搜索用时 15 毫秒
1.
Erwan Diler Vanessa Leblanc Hervé Gueuné Nicolas Larché Valerie Deydier Yannick Linard Didier Crusset Dominique Thierry 《工业材料与腐蚀》2021,72(1-2):218-234
In the context of the high-level radioactive waste disposal CIGEO, the corrosion rate due to microbially influenced corrosion (MIC) has to be evaluated. In France, it is envisaged to dispose of high- and intermediate-level long-lived radioactive waste at a depth of 500 m in a deep geological disposal, drilled in the Callovo-Oxfordian claystone (Cox) formation. To do so, a carbon steel casing will be inserted inside disposal cells, which are horizontal tunnels drilled in the Cox. A specific cement grout will be injected between the carbon steel casing and the claystone. A study was conducted to evaluate the possibility of MIC on carbon steel in the foreseeable high radioactive waste disposal. The corrosiveness of various environments was investigated at 50°C and 80°C with or without microorganisms enriched from samples of Andra's underground research laboratory. The monitoring of corrosion during the experiments was ensured using gravimetric method and real-time corrosion monitoring using sensors based on the measurements of the electrical resistance. The corrosion data were completed with microbiological analyses including cultural and molecular characterizations. 相似文献
2.
3.
S Macphail TH Thomas R Wilkinson JM Davison W Dunlop 《Canadian Metallurgical Quarterly》1993,100(7):673-678
OBJECTIVE: To establish the changes in erythrocyte sodium lithium countertransport (SLC) with advancing normal pregnancy and to determine if these changes were different in pregnancy induced hypertension (PIH). The changes in both groups were assessed in relation to haemodynamic changes. DESIGN: SLC, mean arterial pressure (MAP), cardiac output (CO) and total peripheral vascular resistance (TPVR) were determined serially during normal pregnancy and cross-sectionally in PIH. Women were studied again 20 weeks after delivery where possible. SETTING: Routine antenatal clinic and antenatal ward of a regional reference centre. SUBJECTS: Fifty-one normal primigravid women were studied serially and 41 primigravid women with PIH were studied at time of diagnosis. RESULTS: During normal pregnancy SLC (mmol Li/h/l cells) increased from a nonpregnant value of 0.24 +/- 0.02 (mean +/- SEM) to 0.32 +/- 0.02 at 14 weeks, and 0.37 +/- 0.02 at 20 weeks gestation. This was maintained until 38 weeks (0.40 +/- 0.02). The increase until 20 weeks occurred at the time of greatest change in CO (5.10 +/- 0.18 to 6.79 +/- 0.20 l/min) and TPVR (1327 +/- 58 to 969 +/- 33 dyn/s/cm-5). The decrease in TPVR with a rise in SLC is opposite to the relation reported in essential hypertension so that a functional relation is unlikely. However, the changes within pregnancy were positively correlated (r = 0.43, P < 0.01). In hypertensive pregnancies TPVR was elevated compared with normotensive pregnancies (1543 +/- 100 vs 1090 +/- 37) but the SLC was not different from that found in normotensive pregnancies (0.43 +/- 0.02 vs 0.40 +/- 0.02). CONCLUSIONS: The changes in SLC activity suggest dynamic effects on erythrocyte membrane function during pregnancy. However, no differences could be found between normal and hypertensive pregnancy and SLC is unlikely to be of value as a marker of hypertensive risk during pregnancy. 相似文献
4.
Dr. K. Whybrew J. K. Raine G. R. Dunlop H. Overbye 《The International Journal of Advanced Manufacturing Technology》1993,8(2):111-113
An articulated geometry which overcomes the problem of loss of traction in differentially steered skid tractor automatic guided vehicles is described. 相似文献
5.
Requirements and Services for Metadata Management 总被引:1,自引:0,他引:1
Knowledge-intensive applications pose new challenges to metadata management, including distribution, access control, uniformity of access, and evolution in time. This paper identifies general requirements for metadata management and describes a simple model and service that focuses on RDF metadata to address these requirements. 相似文献
6.
Macwan Richard Benezeth Yannick Mansouri Alamin 《Journal of Mathematical Imaging and Vision》2021,63(7):807-820
Journal of Mathematical Imaging and Vision - Remote photoplethysmography (rPPG) has been at the forefront recently, thanks to its capacity in estimating non-contact physiological parameters such as... 相似文献
7.
Science China Technological Sciences - We use 9 years data of Cluster to study the dependencies of plasma parameters and energy transport in the plasma sheet on the lasting time of... 相似文献
8.
Seung Bum Kil Yannick Augros Yves Leterrier Jan‐Anders E. Mnson Andreas Christel Camille Borer 《Polymer Engineering and Science》2003,43(2):329-343
The rheological properties in solution, in shear and in uniaxial elongation of poly(ethylene terephthalate) (PET) reacted together with hyperbranched polymers (HBPs) were investigated. Two different PET grades, of low and high molecular weights, were compounded with sub‐ to over‐stoichiometric concentrations of HBPs of second and fourth pseudo‐generation, and subsequently subjected to a solid‐state polycondensation (SSP). The formation of microgels, which occurs at high HBP concentration, gave rise to a large increase in melt elasticity and a related decrease in melt strength. At low HBP concentrations, the complex viscosity of the unreacted HBP/PET was considerably reduced, thus demonstrating a lubrication effect of the HBP molecules. During SSP, the intrinsic and shear viscosities exhibited a gradual increase, which was similar for both PET and HBP/PET blends, and was correlated to an increase in molecular weight, through linear‐chain extension and branching reactions. The elongational viscosity of the reactive blends was also increased as a function of reaction time, and this increase was much larger in the case of the HBP/PET blends. A 400% increase in melt strength of the PET was obtained by combining SSP and trace amounts of an HBP of second generation, without any decrease in drawability. 相似文献
9.
Today parametric associative CAD systems must help companies to create more efficient virtual development processes. While dealing with complex parts (e.g. the number of surfaces of the solid) no CAD modeling methodology is existing. Based on the analysis of industrial designers' practices as well as student practices on CAD, we identified key factors that lead to better performance. Our objective in this article is to propose a practical method for complex parts modeling in parametric CAD system. An illustration of the performances and the results obtained by this method are presented comparing the traditional method with the proposed one while using an academic case and then an industrial case. 相似文献
10.
Chateau Marie-Elise Galet Laurence Soudais Yannick Fages Jacques 《Journal of surfactants and detergents》2004,7(4):355-362
A new test was developed to assess the efficiency of no-wiping hard-surface cleaning. The test allows cleaner comparisons
according to their ability to remove greasy soils. The chosen approach minimizes the mechanical forces applied while cleaning
so that the interactions between a detergent solution and the soil to be removed can be characterized. For this, immersion
cleaning was chosen, with coated stainless steel as substrate and pigmented oils as the model soil. Several parameters were
studied in defined ranges using the Experimental Design method and systematic comparisons. The test shows high reliability
on degreasing assessments and is there-fore especially suited to optimization of nonionic surfactant mixes. The originality
of the test lies in the possibility of keeping a visual trace of the cleaned substrate appearance by imprinting it on a piece
of paper. The validation of the test leads to corroboration of several practical observations. Temperature and agitation play
a major role in cleaning efficiency. Detergent solution concentration is a more relevant parameter than pH. Sodium carbonate
is shown to have a higher buffering effect than pentahydrated sodium metasilicate. The test is easy to set up, highly sensitive,
and can be adapted to solve the problems encountered by formulators of detergent cleaners, such as screening the best ethoxylated
fatty alcohol mix for better degreasing properties. 相似文献