排序方式: 共有15条查询结果,搜索用时 31 毫秒
1.
纤维防漏增韧水泥浆应用研究 总被引:1,自引:1,他引:0
在室内进行纤维水泥防漏实验研究和纤维水泥增强增韧实验研究的基础上,进行了纤维防漏增韧水泥浆应用研究。试验中选择了低弹矿物纤维ZRF,该纤维分子链中含部分亲水基团,在一定范围较易分散,可以杂乱地分布于水泥浆中,使水泥硬化后具有显著的抗冲击性,射孔试验结果证实了纤维的这种作用。地面模拟实验结果和现场固井应用试验说明,防漏增韧水泥浆体系能够满足现场固井施工要求,既能提高水泥石韧性,又具有防漏功能,同时解决了固井过程中的水泥浆漏失和水泥石脆性的难题,有利于提高固井质量,延长油气井寿命。 相似文献
2.
LUC SARRAZIN THéRèSE SCHEMBRI PIERRE REBOUILLON 《The International journal of environmental studies》2013,70(4):413-425
A selective method for determining polycyclic aromatic hydrocarbons (PAHs) in sediments using solid‐phase extraction and RP‐HPLC with fluorescence and UV detection is described. The complete analytical method is used to surface sediments from the creek of Cortiou (France). Sewage from the urban area of Marseille is delivered to the creek. PAH levels in sediments (µg/g) range between 2.251 µg/g (for the benzo(a)anthracene) and 0.001 µg/g. The flux of pollution provided by the outfall is preferentially oriented from East to West by the Liguro‐Provenalcal current. The significant values are mainly confined on a perimeter of 2 km around the outfall. The phenanthrene/anthracene and fluoranthene/pyrene ratios indicate pyrolytic and petrogenic contamination. The particulate size observations concerning the sediments show that oxygenated sandy zones, where eliminating mechanisms (desorption, biodegradation) take place, are mainly located on the Chêvres plateau and around Jarre, Plane and Riou Islands. 相似文献
3.
LARISSA DANIELE BOBERMIN LARA SCOPEL MEDEIROS FERNANDA WEBER GIANCARLO TOMAZZONI DE OLIVEIRA LUCÉLIA SANTI WALTER ORLANDO BEYS-DA-SILVA CARLOS-ALBERTO GONÇALVES RÉ QUINCOZES-SANTOS 《Biocell》2022,46(12):2517-2523
Glial cells are crucial for maintaining central nervous system (CNS) homeostasis. They actively participate in immune responses, as well as form functional barriers, such as blood-brain barrier (BBB), which restrict the entry of pathogens and inflammatory mediators into the CNS. In general, viral infections during the gestational period can alter the embryonic and fetal environment, and the related inflammatory response may affect neurodevelopment and lead to behavioral dysfunction during later stage of life, as highlighted by our group for Zika virus infection. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) induces a cytokine storm and, during pregnancy, may be related to a more severe form of the coronavirus disease-19 (COVID-19) and also to higher preterm birth rates. SARS-CoV-2 can also affect the CNS by inducing neurochemical remodeling in neural cells, which can compromise neuronal plasticity and synaptic function. However, the impact of SARS-CoV-2 infection during pregnancy on postnatal CNS, including brain development during childhood and adulthood, remains undetermined. Our group has recently highlighted the impact of COVID-19 on the expression of molecular markers associated with neuropsychiatric disorders, which are strongly related to the inflammatory response. Thus, based on these relationships, we discussed the impact of SARS-CoV-2 infection either during pregnancy or in critical periods of neurodevelopment as a risk factor for neurological consequences in the offspring later in life, focusing on the potential role of glial cells. Thus, it is important to consider future and long-term public health concerns associated with SARS-CoV-2 infection during pregnancy. 相似文献
4.
Abstract A novel approach to interactively acquire knowledge about new objects in a logic environment is presented. When the user supplies an unknown fact containing unknown objects (constants), the system will ask interesting membership and existential queries about the objects. The answers to these questions allow the system to update its knowledge base. Two basic strategies are implemented: one that examines existing Horn clauses for the predicate and another one that uses types. Furthermore, a powerful heuristic based on analogy, to pose the most interesting questions first, is presented. 相似文献
6.
LUC STEELS 《Applied Artificial Intelligence》2013,27(2-3):213-237
This paper introduces a domain model for use in diagnostic problem solving. It emphasizes functional decomposition, rather than behavior, cause-effect, or spatial structure, and represents explicitly the faults of a system together with its possible explanations. Various possible problem solving actions that operate over a function-fault model are introduced. 相似文献
7.
8.
9.
Serratia vaccinii, a novel bacterium isolated from blueberry microflora, increased the phenolic content of berry juices, and thus increased antioxidant activities. The fermentation capacity of Serratia was investigated with Saskatoon berries, cranberries, strawberries and grapes in both aerobic and anaerobic conditions. It was shown to be compatible with wine yeast in anaerobic fermentations, producing wine with high antioxidant activity. The effects of fermented berry juices were tested on lipopolysaccharide/inferon‐gamma‐activated macrophages 264.7 NO(–). Data indicated that fermented berry juices strongly inhibited activated‐macrophage NO production but induced tumor necrosis factor‐alpha production. 相似文献
10.
Feta cheese was manufactured by addition of skim milk retentate powder to the cheese milk. In comparison with the reference cheese 40% of the initial milk was substituted on protein base by the powder. This substitution had little or no effect on proteolysis, lipolysis and the rheological properties of the cheese. Also sensory evaluation demonstrated that the experimental cheese was of the same quality as the reference cheese. Protein substitution proved to have some important advantages, such as a better yield and more economical cheese production. Furthermore, the skim milk retentate powder seems to have fat replacing properties. 相似文献