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T. Rickards 《Design Studies》1980,1(5):262-272
This review concerns itself with the so-called structured aids to creative behaviour. The published literature is outlined and shown to be extensive but fragmentary, diffuse and inconclusive. Four major families of techniques are discussed: brainstorming, synectics, morphological analysis and lateral thinking. Some less well known techniques are also considered briefly, and the problem of classification considered. There is little evidence of an accepted body of knowledge or paradigm, and the field contains contradictory results. It is argued that more attention needs to be directed towards understanding relationships between what the techniques are supposed to be doing on a theoretical level, and what they seem to be achieving in practice. Some fruitful areas for research and for practical actions are suggested, and an attempt has been made to summarize current views of practitioners that have not yet found widespread diffusion. 相似文献
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离子交换膜的重大国家需求和创新研究 总被引:2,自引:1,他引:2
离子交换膜的发展可以追溯到60年前,也是我国最早开发的膜过程,目前已经从当初实验室的研究走向不同工业的应用,特别是近年来,随着国家对环境保护的不断重视,以离子交换膜为基础的过程由于能够实现离子的定向或者选择性迁移,在环境保护、清洁生产和分离等具有举足轻重的地位.本文针对国家目前的产业发展政策阐述了离子交换膜的重大国家需求及其创新研究,对今后该领域的发展进行了展望. 相似文献
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This paper tries to make an overview of the work carried out by scientific community in the area of road helmets safety. In an area that is constantly being pushed forward by market competition, self-awareness of danger and tighter standards, several research groups around the world have contributed to safety gear improvement. 相似文献
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罗丹 《成组技术与生产现代化》2008,25(3):52-56
针对如何整合企业应用资源,提出了基于SOA的企业应用集成架构,针对建立的集成架构,对其核心业务层的基础服务进行了设计,包括业务流程引擎、消息可靠性传输和安全管理服务. 相似文献
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The costs associated with the provision and maintenance of drinking water and wastewater infrastructure represents a significant financial demand worldwide. Maintenance costs are disproportionately high, indicating a lack of adequate durability. There remains a lack of consensus on degradation mechanisms, the performance of various cement types, the role of bacteria in the corrosion process associated with wastewater applications and testing methodologies. This paper presents a review of the literature, outlining the various research approaches undertaken in an effort to address this problem. The findings of these varying approaches are compared, and the different strategies employed are compiled and discussed. It is proposed that a key step in advancing the understanding of the associated deterioration mechanism is a combined approach that considers the interaction between biological and chemical processes. If this can be achieved then steps can be taken to establishing a performance-based approach for specifying concrete in these harsh service conditions. 相似文献
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– | This paper demonstrates the continued relevance of Penrose’s Theory of the Growth of the Firm (1959) (TGF) to explain MNE expansion patterns. |
– | Explaining MNE growth requires explicit attention to three elements not addressed fully by Penrose: (1) technology-based firm-specific advantages, (2) dynamic capabilities and (3) melding location-bound and internationally transferable knowledge, especially through astute human resources management. |
– | TGF includes foundational insights on the dynamic capabilities approach in strategy and contributes to assessing normative models in international strategy. |
– | Penrose did not appreciate fully the unique knowledge recombination challenges prevailing in international business, especially in the context of the large MNE. This uniqueness of knowledge recombination is the raison d’être of international business as a separate field of inquiry. |
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Recent decades have seen considerable growth in computer capabilities, data collection technology and communication mediums. This growth has had considerable impact on our ability to replicate driver behaviour and understand the processes involved in failures in the traffic system. From time to time it is necessary to assess the level of development as a basis of determining how far we have come. This paper sets out to assess the state of the art in the use of computer models to simulate and assess the level of safety in existing and future traffic systems. It reviews developments in the area of road safety simulation models. In particular, it reviews computer models of driver and vehicle behaviour within a road context. It focuses on stochastic numerical models of traffic behaviour and how reliable these are in estimating levels of safety on the traffic network. Models of this type are commonly used in the assessment of traffic systems for capacity, delay and general performance. Adding safety to this assessment regime may allow more comprehensive assessment of future traffic systems. To date the models have focused primarily on vehicular traffic that is, cars and heavy vehicles. It has been shown that these models have potential in measuring the level of conflict on parts of the network and the measure of conflict correlated well with crash statistics. Interest in the prediction of crashes and crash severity is growing and new models are focusing on the continuum of general traffic conditions, conflict, severe conflict, crash and severe crashes. The paper also explores the general data types used to develop, calibrate and validate these models. Recent technological development in in-vehicle data collection, driver simulators and machine learning offers considerable potential for improving the behavioural base, rigour and application of road safety simulation models. The paper closes with some indication of areas of future development. 相似文献
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Derya Burcu Hazer Ebru Kılıçay Baki Hazer 《Materials science & engineering. C, Materials for biological applications》2012,32(4):637-647
Biomaterials have played an important role in the treatment of disease and the improvement of health care. Synthetic and naturally occurring biodegradable and biocompatible polymers have been used as biomaterials. Polyhydroxyalkanoates (PHAs) are promising materials for biomedical applications because they are biodegradable, non-toxic and biocompatible. We will shortly summarize the modification reactions, which include functionalization and grafting reactions, to improve the mechanical, thermal and hydrophilic properties of PHAs. The use of the modified PHAs in numerous biomedical applications, such as sutures, cardiovascular patches, wound dressings, scaffolds in tissue engineering, tissue repair/regeneration devices, drug carriers will be discussed in this review. 相似文献
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Critical review of the state of the art in multi-material fabrication via directed energy deposition
D.R. Feenstra R. Banerjee H.L. Fraser A. Huang A. Molotnikov N. Birbilis 《Current Opinion in Solid State & Materials Science》2021,25(4):100924
Directed energy deposition (DED) is an additive manufacturing technique that employs laser melting to permit for the free form manufacturing of components from many input materials from powder or wire form of feedstock. The nature of DED processes and advancements thereof has led to research that has been aimed at leveraging this additive manufacturing technology for the fabrication of high-value metallic alloys in addition to the exploration of multi-material composites and components – many of which are only possible to produce via DED. Herein, a critical review of the present body of research regarding DED of multi-materials is presented. Assessed are the developing research trends, design methodologies, common issues and challenges, as well as identification of the areas where further research should be directed. 相似文献
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Rheology, flow behaviour and heat transfer of ice slurries: a review of the state of the art 总被引:1,自引:0,他引:1
This paper reviews recent studies on rheology, flow behaviour and heat transfer of two-phase aqueous secondary refrigerants (ice slurries). The difficulties in measuring their rheological properties for which standard rheometers prove to be poorly adapted are analysed. Special attention is paid to “vane-in-cup” rheometers, which can make it possible to determine the yield stress. Pressure losses in cylindrical tubes have been measured by many authors. Even if the results generally agree with two-phase flow theory, divergences in sensitivity to the solid fraction can be observed. The stratification observed by some authors for small-Reynolds-number flows and its effects on the pressure drop are addressed. In a last part, information concerning numerical values of the heat transfer coefficient of ice slurries are summarized. Heat transfer coefficients depend on many parameters, but are largely influenced by the flow regime. A geometry of heat exchanger is then proposed, which has already been effective for single-phase flows, and which may enhance heat transfer in ice slurry flows.
Résumé
Cet article passe en revue des études récentes concernant la rhéologie, le comportement des écoulements et le transfert thermique des frigoporteurs diphasiques aqueux (coulis de glace). Les difficultés de mesure des propriétés rhéologiques, pour lesquelles des rhéomètres courants s'avèrent mal adaptés, sont analysées. Une attention particulière est portée sur les rhéomètres du type « vane-in-cup » qui permettent de déterminer la contrainte seuil d'un matériau. Les pertes de charge linéaires dans des canalisations cylindriques ont été mesurées par de nombreux auteurs. Même si les résultats sont genéralement conformes à la théorie des écoulements diphasiques, on peut observer des divergences quant à la sensibilité à la concentration en glace. La stratification, observée par quelques auteurs pour des écoulements à faible nombre de Reynolds, et ses effets sur la chute de pression sont étudiés. Dans une dernière partie, les valeurs numériques du coefficient de transfert thermique des coulis de glace sont récapitulées. Les coefficients de transfert thermique dépendent de nombreux paramètres, mais sont fortement influencés par le régime d'écoulement. Nous proposons enfin un type d'échangeur de chaleur, dont l'efficacité a déjà été remarquée pour des écoulements monophasiques, et il pourrait s'avérer tout à fait adapté à des écoulements de coulis de glace. 相似文献14.
本文从政策、经济、技术、市场竞争等视角分析了通信服务企业实施整合营销传播的动因,指出整合营销传播视角下通信服务企业品牌接触点管理的主要内容是客户服务品牌接触点识别、有效识别关键接触点、对品牌接触点实施有效管理等,并对通信服务企业如何进一步做好品牌接触点管理提出对策建议。 相似文献
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Azriel Rosenfeld 《Sadhana》1983,6(2):145-152
Image analysis techniques applicable to remote sensing data are reviewed, with emphasis on recent developments. The topics
covered include image modelling, feature detection, segmentation and classification, texture analysis, and matching. 相似文献
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Process modelling is the foundation of developing process controllers for monitoring and improving process/system health. Modelling process behaviours using a pure empirical approach might not be feasible due to limitation in collecting large amount of data. Engineering models provide valuable information about processes’ general behaviours but they might not capture distinct characteristics in the particular process studied. Many recent publications presented various ideas of using limited experimental data to adjust engineering models for making them suitable for certain applications. However, the focuses there are global adjustments, where modification of engineering models impacts the entire model-application region. In practice, some engineering models are only valid in a part of experimental data domain. Moreover, many discrepancies between engineering models and experimental data are in local regions. For example, in a chemical vapour deposition process, at high temperatures a process may be described by a diffusion limited model, while at low temperatures the process may be described by a reaction limited model. To address these problems, this article proposes two approaches for integrating engineering and data models: local model calibration and local model averaging. Through the local model calibration, the discrepancies between engineering’s first-principle models and experimental data are resolved locally based on experts’ feedbacks. To combine models adjusted locally in some regions and also models required little adjustments in other regions, a model averaging procedure based on local kernel weights is proposed. The effectiveness of the proposed method is demonstrated on simulated examples, and compared against a well-known existing global-adjustment method. 相似文献
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F. H. Xavier-Junior C. Vauthier A. R. V. Morais E. N. Alencar 《Drug development and industrial pharmacy》2017,43(5):700-714
AbstractNatural oils are extremely complex mixtures containing compounds of different chemical nature. Some of them have physiological or therapeutic activities that may act either alone or in synergy. Therefore, they are used in the pharmaceutical, agronomic, food, sanitary and cosmetic industries. Today, the interest in bioactive natural oils is growing due to their immense potential to prevent and treat numerous human diseases. Formulation in microemulsions (MEs) containing natural oils appeared suitable to improve pharmaceutical and biopharmaceutical properties of bioactive compound derivatives from these oils. Microemulsion systems are thermodynamically stable, transparent, and are isotropic dispersions consisting of oil and water stabilized by an interfacial film of surfactants, typically in combination with a cosurfactant. They can protect labile compounds from premature degradation, control release, increase solubility and hence enhance the bioavailability of poorly bioavailable compounds. The aim of this work was to review the various advantages of bioactive compounds presented in natural oil loaded ME systems to be used as delivery systems. First, the state of the art of the parameters involved in the ME formation, including the basic concepts of the physicochemical formulation of the ME systems, and the main aspects of production and the energy responsible for their formation were reported. The second section describes the use of ME systems and reviews the recent applications of natural oil-loaded in the ME systems as the bioactive compound in the formulation. 相似文献
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An overview is given of methods to determine the strength and fracture energy of concrete subjected to uniaxial tension. The test method is often erroneously--and persistently--referred to as the `direct tension test'. After a brief review of historical, mostly indirect methods, the paper focuses on more recent servo-controlled testing techniques. Assessment of effects like secondary bending, and rotation and/or translations of the loading platens, as well as size/scale effects and environmental effects on fracture seem important for a proper definition of tensile strength and fracture energy. Implications for modeling are debated. The methods can be transferred directly to studies of other quasi-brittle geo-materials like natural rocks, clay and ice, fired clay bricks, plaster and the like. 相似文献
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《Virtual and Physical Prototyping》2013,8(3):137-145
The medical field is one in which the need for customization can be clear cut, as providing tailored devices and implants for unique physiologies can provide for a better overall treatment than the use of ‘off the shelf’ devices and implants. Customization in the production of medical products can be roughly divided into consideration of medical devices, and of implantable parts or systems. The present paper outlines the current state of the art in both of these areas, presents details of projects that are ongoing at the University of Leeds and outlines future research directions. 相似文献
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K. W. Dalgarno J. H. Pallari J. Woodburn K. Xiao D. J. Wood R. D. Goodridge C. Ohtsuki 《Virtual and Physical Prototyping》2006,1(3):137-145
The medical field is one in which the need for customization can be clear cut, as providing tailored devices and implants for unique physiologies can provide for a better overall treatment than the use of 'off the shelf' devices and implants. Customization in the production of medical products can be roughly divided into consideration of medical devices, and of implantable parts or systems. The present paper outlines the current state of the art in both of these areas, presents details of projects that are ongoing at the University of Leeds and outlines future research directions. 相似文献