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排序方式: 共有297条查询结果,搜索用时 15 毫秒
31.
Stephane Neuville 《Thin solid films》2007,515(17):6619-6653
Hard carbon coatings hold the key to improved performance for many types of products. However the achievement of these improvements requires the selection of the appropriate type of carbon coating and therefore the correct process and appropriate deposition parameters. The huge range of properties achievable in carbon coatings is mainly due to the ability of carbon to form different types of interatomic bonds, to take up different sites, and to adopt different structures. In addition to intrinsic material properties, other factors must also be considered for each application, such as the adhesion level achievable and coating cost. This complex situation explains why the number of applications for hard carbon films is still more limited than originally expected. Despite the considerable progress achieved during the last decade in hard coating technologies, practical results often appear conflicting, with differences in properties occurring even within the same types of coatings. Furthermore, the many different deposition systems and processes which have been developed introduce further complications in regard to (for example) achievable coating uniformity and deposition rates. Thus, there is often confusion in the use of certain fundamental principles, especially regarding the growth mechanisms and the effects which produce more dense homogeneous and stable coating materials. This is especially true for the improved properties of tetrahedral amorphous carbon films, which are different from previously reported diamond-like carbon materials, and can be created by adapting and improving existing industrial processes, to offer advantages compared to earlier coatings, and hence possibilities for important new applications. This paper discusses issues relating to intrinsic material properties, and practical aspects such as adhesion, to provide a framework for the development, selection and use of hard carbon coatings in practical situations. 相似文献
32.
EDnline PhillippeRabier StephaneSerrier 《电子设计应用》2003,(9):66-67
异步数字用户线路(ADSL)调制解调器由于同普通电话线相连,容易遭受电击。因此,必须施加恰当保护,以抵抗破坏性过压和压流的冲击。通晓保护标准、指导原则和器件,可以提高设计人员保护ADSL调制解调器的电话线及数据线免遭过压冲击的能力。如表1所示,标准的选择取决于设备类型、在网络中的位置和网络的地理区域。对于并联元器件,特别是具有急剧短路特性的器件,可以提供必要的雷电冲击保护功能。急剧短路器件的优点是可以高效地短接电话双绞线,消除过压,而且热量极小。在正常电压下,急剧短路器件保持开路状态。器件的电流处理能力取决于器… 相似文献
33.
Predictions from interpersonal traits to affect were examined in the context of 3 models. In the global trait model, traits were used to predict affect aggregated over a 20-day period. In the situational congruence model, traits were used to predict affect in trait-relevant situations. In the behavioral concordance model, the co-occurrence between behaviors and affect was examined for individual participants, and then traits were used to predict the degree to which behavior and affect co-occurred. No support was found for the global trait and situational congruence models. Support was found for the behavioral concordance model for 3 of the 4 traits. Individuals high on agreeableness and quarrelsomeness experienced pleasant affect when they engaged in behaviors concordant with their traits. Individuals high on agreeableness, quarrelsomeness, and dominance experienced unpleasant affect when they engaged in behaviors opposite to their traits. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
34.
Stísová V Goffinont S Spotheim-Maurizot M Davídková M 《Radiation protection dosimetry》2006,122(1-4):106-109
The exposure of a DNA-protein regulatory complex to ionising radiation induces damage to both partner biomolecules and thus can affect its functioning. Our study focuses on a complex formed by the estrogen response element (ERE) DNA and the recombinant human estrogen receptor alpha (ER), which mediates the signalling of female sex hormones, estrogens. The method of native polyacrylamide retardation gel electrophoresis is used to study the stability of the complex under irradiation by low LET radiation ((60)Co gamma rays) and the ability of the separately irradiated partners to form complexes. The relative probabilities of ERE DNA strand breakage and base damages as well as the probabilities of damages to the ER binding domain are calculated using the Monte Carlo method-based model RADACK. 相似文献
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37.
Christophe Bredillet Stephane Tywoniak Mahshid Tootoonchy 《International Journal of Project Management》2018,36(5):744-761
The growing popularity of Project Management Offices (PMOs) as organizational structures is grounded in the assumption they support more efficient and effective project management for better strategy implementation. However, research emphasizes they fail to deliver expected value: their unstable nature precludes the delivery of long-term benefits. This is compounded by the absence of a theory of PMO change and adaptation. Recent research, taking a co-evolution lens rooted in evolutionary theory, suggests that PMOs should be studied in relation to the broader organizational context, in order to better capture the dynamic interplay and fit between them. In this study, taking a routine perspective as micro-foundation and unit of analysis, we focus on the co-evolution between PMO and Project Portfolio Management (PfM) as organizational capability for six case studies. A structural analysis of the relational routines' system between PMO, PfM and the Organizational context allow us to unveil dynamics at stake, i.e. why and how changes occur, as well as eigen behaviors and the changing states of various routines elements (influential, mediating, dependent or not-influential). This study makes five contributions. We show that: 1) PMO and PfM can be conceptualized as collections of routines, 2) PMO and PfM co-evolve over time to adapt to organizational context influence, 3) the co-evolution of a routines' system, abstracted as a non-trivial machine, exhibits an eigen behavior, 4) applying a structural analysis approach allows to simulate the dynamics of a routines' system and to unveil the role of key routine elements and 5) eigen values of routines' systems allow to characterize their eigen behavior. 相似文献
38.
John F. Timms Elif Arslan-Low Musarat Kabir Jenny Worthington Stephane Camuzeaux John Sinclair Joanna Szaub Babak Afrough Vladimir N. Podust Evangelia-Ourania Fourkala Myriam Cubizolles Florian Kronenberg Eric T. Fung Aleksandra Gentry-Maharaj Usha Menon Ian Jacobs 《Proteomics. Clinical applications》2014,8(11-12):982-993
39.
Stephane Parola Beatriz Julián‐López Luís D. Carlos Clément Sanchez 《Advanced functional materials》2016,26(36):6506-6544
Research on hybrid inorganic‐organic materials has experienced an explosive growth since the 1980s, with the expansion of soft inorganic chemistry based processes. Indeed, mild synthetic conditions, low processing temperatures provided by “chimie douce” and the versatility of the colloidal state allow for the mixing of the organic and inorganic components at the nanometer scale in virtually any ratio to produce the so called hybrid materials. Today a high degree of control over both composition and nanostructure of these hybrids can be achieved allowing tunable structure‐property relationships. This, in turn, makes it possible to tailor and fine‐tune many properties (mechanical, optical, electronic, thermal, chemical…) in very broad ranges, and to design specific multifunctional systems for applications. In particular, the field of “Hybrid‐Optics” has been very productive not only scientifically but also in terms of applications. Indeed, numerous optical devices based on hybrids are already in, or very close, to the market. This review describes most of the recent advances performed in this field. Emphasis will be given to luminescent, photochromic, NLO and plasmonic properties. As an outlook we show that the controlled coupling between plasmonics and luminescence is opening a land of opportunities in the field of “Hybrid‐Optics”. 相似文献
40.
Optical solution for bounded NP-complete problems 总被引:1,自引:0,他引:1
We present a new optical method for solving bounded (input-length-restricted) NP-complete combinatorial problems. We have chosen to demonstrate the method with an NP-complete problem called the traveling salesman problem (TSP). The power of optics in this method is realized by using a fast matrix-vector multiplication between a binary matrix, representing all feasible TSP tours, and a gray-scale vector, representing the weights among the TSP cities. The multiplication is performed optically by using an optical correlator. To synthesize the initial binary matrix representing all feasible tours, an efficient algorithm is provided. Simulations and experimental results prove the validity of the new method. 相似文献