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排序方式: 共有368条查询结果,搜索用时 15 毫秒
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2.
BBN (BaBi2Nb2O9) is very interesting and promising lead free material with relaxor properties in capacitors, sensors and actuators. 相似文献
3.
Malgorzata Kloc Ahmed Uosef Jacek Z. Kubiak Rafik Mark Ghobrial 《International journal of molecular sciences》2021,22(1)
The development, progression, or stabilization of the atherosclerotic plaque depends on the pro-inflammatory and anti-inflammatory macrophages. The influx of the macrophages and the regulation of macrophage phenotype, inflammatory or anti-inflammatory, are controlled by the small GTPase RhoA and its downstream effectors. Therefore, macrophages and the components of the RhoA pathway are attractive targets for anti-atherosclerotic therapies, which would inhibit macrophage influx and inflammatory phenotype, maintain an anti-inflammatory environment, and promote tissue remodeling and repair. Here, we discuss the recent findings on the role of macrophages and RhoA pathway in the atherosclerotic plaque formation and resolution and the novel therapeutic approaches. 相似文献
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The University of Sussex In-School Teacher Education Project (InSTEP) uses interactive video technologies to enhance initial teacher education programmes for science trainee teachers. With four Internet Protocol cameras and mounted microphones in both school laboratories and the university teaching room, trainees and their tutors have access to live interaction with schools. This paper presents some of the findings of a 2 year evaluation of InSTEP aimed at identifying the benefits for trainee teachers. There has been an increase in the use of video material for teacher training purposes, however, trainee teachers are often intimidated by carefully selected extracts featuring experienced teachers. InSTEP activities are live and capitalise on all the opportunities associated with normal classroom practice. Literature points to InSTEP-type activities having the potential to enhance the development of trainees’ observation skills, develop reflective thinking, to provide authentic illustrations of classroom practice, enable remote observation and facilitate the coaching of trainees by mentors. A fourth generation model of evaluation was undertaken with data generated by semi-structured interviews with university tutors and mentors supported by a questionnaire and group interviews with the trainees. Our main findings point to InSTEP enhancing and accelerating the growth of trainee teachers’ professional knowledge through enabling reflective practice, facilitating collaborative learning and supporting the development of the language of pedagogy. 相似文献
6.
Malgorzata Plaza 《Information Systems Frontiers》2008,10(3):347-359
Although the Earned Value Method (EVM), a multi-dimensional project control system, has been widely used since 1960, there
has been little research focused specifically on its application in IS implementation. The management of IS projects—including
the accurate forecasting of project duration—is complicated by the strong impact of the learning curve on the effectiveness
of EVM. This study makes new contributions by advancing formulas for the accurate prediction of project duration, and by developing
a decision support model in which the learning curve is fully integrated with EVM, and performance changes due to learning
are isolated from other factors affecting project duration. The study makes three contributions to the understanding and use
of EVM in IS implementation: (1) It provides an extended version of EVM, (2) it provides an illustration of the application
of EVM to a real project situation based on empirical data from an ERP implementation project, and (3) it provides a theoretical
basis for empirical studies of IS project control techniques. The decision support model can be used to determine both the
learning curve coefficient and the project completion date during the early stages of a project, and it thus offers a significant
practical contribution to the management of IS projects.
Dr. Margaret Plaza is an Associate Professor of Information Technology Management at Ryerson University and a Senior Research Scientist in IITM. She holds an M.Sc. in Mechanical Engineering and a Ph.D. in Production Engineering from Politechnika Krakowska (Cracow University of Technology) where she specialized in flexible manufacturing systems. Dr. Plaza is also a PEng. (Ontario), PMP, and CIA and has over 20 years’ industry experience working with consulting and manufacturing firms in both private and public sectors. She managed or provided consulting for ERP and supply chain implementations. Her current research focuses on organizational learning, technology management and the supply chain. She has developed decision models and decision support technologies to assist managers with problems in new technology implementations. 相似文献
Malgorzata PlazaEmail: |
Dr. Margaret Plaza is an Associate Professor of Information Technology Management at Ryerson University and a Senior Research Scientist in IITM. She holds an M.Sc. in Mechanical Engineering and a Ph.D. in Production Engineering from Politechnika Krakowska (Cracow University of Technology) where she specialized in flexible manufacturing systems. Dr. Plaza is also a PEng. (Ontario), PMP, and CIA and has over 20 years’ industry experience working with consulting and manufacturing firms in both private and public sectors. She managed or provided consulting for ERP and supply chain implementations. Her current research focuses on organizational learning, technology management and the supply chain. She has developed decision models and decision support technologies to assist managers with problems in new technology implementations. 相似文献
7.
The crystal structure and dielectric properties as a function of temperature for Ba-based with Bi-layered structure BaBi2Nb2O9 (BBN) ceramics were investigated. The obtained results confirmed the relaxor ferroelectric behavior of the studied ceramics,
including a strong frequency dispersion of the permittivity maximum and a visible shift of its temperature with frequency.
Analysis of the real and imaginary part of permittivity allowed us to determine the values of Burn’s temperature and of the
freezing temperature characterizing the relaxor ferroelectrics. The physical processes, responsible for the relaxor behavior
of the studied ceramics are discussed. The additional low frequency dielectric dispersion at high temperatures in the paraelectric
phase range was also observed. Correlation between this dispersion and the thermally stimulated depolarization current was
ascertained. 相似文献
8.
Viscosity is one of the most important attributes of rye-based products related to some health benefits. To identify the factors affecting arabinoxylan-dependent extract viscosity (AX-EV) of rye bread, the structural features of water-extractable arabinoxylans (WE-AXs) and their ammonium sulphate precipitated subfractions were investigated in breads with varied viscosities. Also, an endoxylanase activity in the starting flours was examined. The HPSEC-RI profiles revealed the higher extent of AX depolymerisation in whole-meal bread (WMB) when compared to that in endosperm bread (EB), resulting in its lower AX-EV. This was mostly related to lower molecular weight of the parent WE-AX fraction with distinctly lower proportion of 2-Xylp in the chain. The AX-EV of rye bread decreased with decreasing proportion of AX-I, the major subfraction with 3-Xylp as only branching site. The endoxylanase activity was at least two times lower in endosperm flour than that in WM and negatively correlated with the AX-EV of WMB. The importance of densely substituted AX subfractions with exclusively 2-Xylp and 2,3-Xylp branches, protecting the AX-I from enzymic degradation during bread-making, has been evidenced. 相似文献
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Synthesis of trimethylene carbonate/ϵ‐caprolactone copolymers initiated with zinc alkoxide: influence of copolymer chain microstructure on thermal and mechanical properties
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Malgorzata Pastusiak Piotr Dobrzynski Janusz Kasperczyk Michal Sobota Bozena Kaczmarczyk Henryk Janeczek 《Polymer International》2017,66(9):1259-1268
Ethylzinc(II ) ethoxide is a highly active and efficient initiator for the bulk polymerization of 1,3‐trimethylene carbonate and its copolymerization with ? ‐caprolactone. This initiator allows one to obtain (co)polymers with high molar masses in quite a short time. Significant difference in co‐monomer reactivity and relatively low participation of intermolecular transesterification processes lead to the obtained copolymers being characterized by a gradient chain microstructure. In 13C NMR spectra, in all regions, we observed the presence of triads which were distinctly represented by four peaks for the carbonyl signal. Mechanical tests showed that copolymers containing 70% and more of ? ‐caprolactone presented a relatively high Young's modulus and a very high maximum elongation factor; therefore these materials are promising in many biomedical applications. Due to the high reaction rate, we also made an attempt at copolymerization using reactive extrusion which gave promising results. © 2017 Society of Chemical Industry 相似文献