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排序方式: 共有791条查询结果,搜索用时 31 毫秒
41.
Sirine ChehaidiVincent Salles Sylvie FoucaudAlexandre Maitre Paul Goursat 《Journal of the European Ceramic Society》2011,31(6):1113-1122
We performed pyrolysis of SiCNAlH and SiCNYOH nanopowder precursors under a reactive atmosphere (Ar/NH3/H2) with various compositions of ammonia (NH3) and dihydrogen (H2) to diminish C content, which is deleterious for thermal stability and sintering of the powders. This paper continues a previous work on the fabrication of an Si3N4/SiC composite without free C by studying the effect of H2 on the C/N atomic ratio of the powder. We studied the influence of the nature of the gaseous mixture (Ar/NH3/H2) on the powder composition. Elemental analysis showed that the introduction of H2 in the pyrolysis atmosphere limited the decomposition of NH3 and allowed for control of the C/N ratio. This behaviour can be explained by the structural evolution observed by 29Si NMR spectrometry but also by Fourier transform infrared and Raman spectroscopy. An Si3N4/SiC composite, with traces of free C, was obtained after post-pyrolysis heat treatment of the powders synthesized with 10 wt.% of H2 and 25 wt.% NH3. 相似文献
42.
43.
Véronique Demers-Mathieu Sylvie F. Gauthier Michel Britten Ismaïl Fliss Gilles Robitaille Julie Jean 《International Dairy Journal》2013,28(2):94-101
Ultrafiltration permeate of whey protein tryptic hydrolyzate was processed by nanofiltration (NF) to obtain retentate (NFR) and permeate (NFP) that were then tested as inhibitors of Listeria, Staphylococcus aureus and Escherichia coli. NFR at 20 mg mL?1 was most effective as an inhibitor (P < 0.001); whereas E. coli was relatively resistant, the effect on Listeria and S. aureus was greater at 20 mg mL?1 than at 10 mg mL?1 (P < 0.01). Peptide analysis revealed that NFR was rich in anionic peptides over eight amino acid residues in length. The antibacterial activity of two anionic peptides (84–91 and 125–135) and a cationic peptide (36–42) derived from β-lactoglobulin was tested. Peptide 125–135 was more inhibitory (P < 0.05) than peptide 84–91 against Listeria monocytogenes and S. aureus; peptide 36–42 was not inhibitory. NFR appears to have potential as a natural bio-preservative. 相似文献
44.
45.
Proliferative effects of synthetic peptides from β-lactoglobulin and α-lactalbumin on murine splenocytes 总被引:1,自引:0,他引:1
Arnaud Jacquot Sylvie F. Gauthier Rejean Drouin Yvan Boutin 《International Dairy Journal》2010,20(8):514-521
Eleven peptides, selected on the basis of physicochemical characteristics and their theoretical release from β-lactoglobulin (β-Lg) and α-lactalbumin (α-La) by trypsin or chymotrypsin, were chemically synthesised to evaluate their immunomodulating properties. Murine splenocyte proliferation in the absence and presence of mitogen and different peptide concentrations were measured after 72–96 h incubations. β-Lg f78–83 had no effect on proliferation; β-Lg f15–20, f55–60, f84–91, f92–105, f139–148, f142–148 and α-La f10–16 stimulated proliferation to different extents; β-Lg f1–8, f102–105 and α-La f104–108 showed a cytotoxic effect. Regression analysis revealed the relationship of positive charge, hydrophobicity and length to the stimulatory proliferative effect. β-Lg f15–20, f55–60 and f139–148 also induced various inhibiting and/or stimulating effects on cytokine secretion. The results confirm that peptides releasable by digestive enzymes from α-La and β-Lg have the potential to influence the specific immune response through the modulation of splenocyte proliferation and cytokine secretion. 相似文献
46.
Sylvie Trudel Jean-Marc Lavoie Marie-Claude Paré Witold Suryn 《Software Quality Journal》2006,14(1):7-23
Many small software organizations have recognized the need to improve their software product. Evaluating the software product
alone seems insufficient since it is known that its quality is largely dependant on the process that is used to create it.
Thus, small organizations are asking for evaluation of their software processes and products. The ISO/IEC 14598-5 standard
is already used as a methodology basis for evaluating software products. This article explores how it can be combined with
the CMMI to produce a methodology that can be tailored for process evaluation in order to improve their software processes.
SM: CMMI is a service mark of Carnegie-Mellon University.
Sylvie Trudel has over 20 years of experience in software. She worked for more than 10 years in development and implementation of management
information systems and embedded real-time systems. Since 1996, she works as a process improvement specialist, implementing
best practices into organizations processes from CMM and CMMI models. She performed several CMM and CMMI assessments and participated
in many other CMM assessments such as CBA IPI, SCE, and other proprietary methods. She obtained a bachelors degree in computer
science in 1986 from Laval University in Québec City and a Masters degree in Software Engineering at école de Technologie
Supérieure (éTS) in Montréal. Sylvie is currently working as a software engineering advisor at the Centre de Recherche Informatique
de Montréal (CRIM).
Jean-Marc Lavoie has been working in software development for over 10 years. He performed and published a comparative study between the guide
to the SWEBOK and the CMMI in 2003. Jean-Marc obtained a bachelor degree in Electrical Engineering. He is pursuing a Masters
degree in Software Engineering at école de Technologie Supérieure (éTS) in Montréal while working as a software architect
at Trisotech.
Marie-Claude Pare has been working in software development for 7 years. Marie-Claude obtained a bachelor degree in Software Engineering from
école Polytechnique in Montréal. She is pursuing a Masters degree in Software Engineering at école de Technologie Supérieure
(éTS) in Montréal while working as a software engineer at Motorola GSG Canada.
Dr Witold Suryn is a Professor at the école de technologie supérieure, Montreal, Canada (engineering school of the Université du Québec network
of institutions) where he teaches graduate and undergraduate software engineering courses and conducts research in the domain
of software quality engineering, software engineering body of knowledge and software engineering fundamental principles. Dr
Suryn is also the principal researcher and the director of GELOG : IQUAL, the Software Quality Engineering Research Group
at école de technologie supérieure. From October 2003 Dr. Suryn holds the position of the International Secretary of ISO/IEC
SC7 – System and Software Engineering. 相似文献
47.
The lateral heterogeneity of lipids in the thylakoid membrane has been questioned for over 20 yrs. It is generally believed
that glycerolipids are asymmetrically distributed within the plane of the membrane. In the present investigation, we isolated
several thylakoid membrane domains by using sonication followed by separation in an aqueous dextran-polyethylene glycol two-phase
system. This technique, which avoids detergent treatments, allowed us to obtain stroma and grana lamellae vesicles as well
as grana central core and grana margin vesicles from thylakoids. The relative distribution of the four lipid classes, i.e.,
monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sulfoquinovosyldiacylglycerol, and phosphatidylglycerol, was found
to be statistically identical in all four thylakoid fractions and in whole thylakoids. Similarly, the relative amount of fatty
acids in each individual lipid and the eight main phosphatidylglycerol molecular species was identical in all thylakoid membrane
fractions tested as well as in the intact thylakoid membrane. Based on presently available procedures for obtaining thylakoid
subfractions that are unable to discriminate microdomains within the membrane, it is concluded that glycerolipids are evenly
distributed within the plane of the thylakoid membrane. These data are discussed in terms of “bulk” and “specific” lipids. 相似文献
48.
The use of zinc-coated steels for automotive, construction, and appliance applications has grown continually during the past
decade. An understanding of the effects of process parameters and substrate characteristics on the coating microstructure
is critical for optimizing the performance of the zinc-based coatings. This paper presents an overview of the application
of advanced electron and focused-ion-beam microscopy techniques to characterize the microstructure of galvanized and galvannealed
coatings. 相似文献
49.
For a company, information and communication system is a product of divergent rationalities which come to clash. Dissimilar logic leads to diverging projects : one focused on information aims to integrate and control its processing and flow rate, the other prefers to look at communication as a vector of working together among peers. However beyond these conflicts appears a factor of coherence and cohesion which ultimately helps the rationalities to join. A management able to combine integration of wage earners by identifying the objectives of the company and individualism (information systems is a vector of such a strategy). The goal is to avoid a major risk in form of mass action. The remaining question turns about the ability for innovation allowed to wage-earners in a company driven by standards and believes, in fact ideology. Sticking to standards, in other words conformity seems to leave out marginal handling and conflicting situation sources of innovative spirit. 相似文献
50.
Mach UR Hackling AE Perachon S Ferry S Wermuth CG Schwartz JC Sokoloff P Stark H 《Chembiochem : a European journal of chemical biology》2004,5(4):508-518
Based on N-alkylated 1,2,3,4-tetrahydroisoquinoline derivatives, which are structurally related to the partial agonist BP 897, a series of novel, selective dopamine D3 receptor antagonists has been synthesised. Derivatisation included changes in the arylamide moiety and the tetrahydroisoquinoline substructure leading to compounds with markedly improved selectivities and affinities in the low nanomolar concentration range. From the 55 structures presented here, (E)-3-(4-iodophenyl)-N-(4-(1,2,3,4-tetrahydroisoquinolin-2-yl)butyl)acrylamide (51) has high affinity (Ki(hD3)=12 nM) and a 123-fold preference for the D3 receptor relative to the D2 receptor subtype. Its pharmacological profile offers the prospect of a novel radioligand as a tool for various dopamine D3-receptor-related in vitro and in vivo investigations. 相似文献