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排序方式: 共有469条查询结果,搜索用时 406 毫秒
81.
M Petri 《Canadian Metallurgical Quarterly》1998,10(5):426-430
T-lymphocyte recirculation appears to be slower in nude or irradiated rats as compared with normal rats. A mathematical model of T-lymphocyte recirculation that incorporates interactions between T cells and dendritic cells in the lymphoid tissue is presented. It is shown that these interactions are able to explain the differences in recirculation times between normal and nude or irradiated rats, and also the time-scales seen in long-term thoracic duct cannulations. 相似文献
82.
83.
Dario Petri 《Measurement》1996,19(3-4):147-157
The accuracy performance that an be achieved by post-processing the samples provided by a dithered quantizer is analysed in this paper for both stochastic and deterministic dithering. In the former case the quantization error average and variance are considered and the number of effective bits of the system output is evaluated for uniformly and Gaussian distributed dither signals. Then the accuracy achieved by using a deterministic dithering is analysed and a new approach for optimizing the system performance is proposed. All the reported results have been validated by means of computer simulations. 相似文献
84.
For a significant period of time, B-ISDN will coexist with the 64-kb/s-based (narrowband) ISDN. The specification of a concept and the mapping functions employed for interworking between the two networks, in particular for voice services, is a major factor for the success of B-ISDN 相似文献
85.
Microstructural Studies of Cold Sprayed Copper,Nickel, and Nickel-30% Copper Coatings 总被引:1,自引:0,他引:1
Heli Koivuluoto Juha Lagerbom Petri Vuoristo 《Journal of Thermal Spray Technology》2007,16(4):488-497
Cold spraying enables to produce metallic coatings with low porosity level and low oxygen content. Several material properties
such as electrical conductivity and corrosion resistance rely on these properties. Aim of this study was to characterize microstructural
properties of cold sprayed copper, nickel, and nickel-30%copper coatings. Microstructures, denseness, and deformation of particles
were investigated. SEM analysis and corrosion tests were done to get information of through-porosity. Open porosity has an
important role on protectiveness of anodically protective coatings, such coating materials like copper and nickel. In this
study, cold-sprayed Cu coating was fully dense. However, cold-sprayed Ni and Ni-30%Cu coatings seemed to be microstructurally
dense but some porosity in some areas of the coatings especially in some parts of particle boundaries was noticed after corrosion
tests. Furthermore, effect of annealing to microstructure and corrosion test behavior was studied. Cold sprayed Ni coating
became denser during heat treatment. 相似文献
86.
Analytical affective design with ambient intelligence for mass customization and personalization 总被引:2,自引:0,他引:2
Roger J. Jiao Qianli Xu Jun Du Yiyang Zhang Martin Helander Halimahtun M. Khalid Petri Helo Cheng Ni 《International Journal of Flexible Manufacturing Systems》2007,19(4):570-595
The fulfillment of individual customer affective needs may award the producer extra premium in gaining a competitive edge.
This entails a number of technical challenges to be addressed, such as the elicitation, evaluation, and fulfillment of affective
needs, as well as the evaluation of affordability of producers to launch the planned products. Mass customization and personalization
have been recognized as an effective means to enhance front-end customer satisfaction while maintaining back-end production
efficiency. This paper proposes an affective design framework to facilitate decision-making in designing customized product
ecosystems. In particular, ambient intelligence techniques are applied to elicit affective customer needs. An analytical model
is proposed to support affective design analysis. Utility measure and conjoint analysis are employed to quantify affective
satisfaction, while the producer affordability is evaluated using an affordability index. Association rule mining techniques
are applied to model the mapping of affective needs to design elements. Configuration design of product ecosystems is optimized
with a heuristic genetic algorithm. A case study of Volvo truck cab design is reported with a focus on the customization of
affective features. It is demonstrated that the analytical affective design framework can effectively manage the elicitation,
analysis, and fulfillment of affective customer needs. Meanwhile, it can account for the manufacturer’s capabilities, which
is vital for ensuring a profit margin in the mass customization and personalization endeavor. 相似文献
87.
Na Li Lifang Qiao Jintao He Shuxue Wang Liangmin Yu Petri Murto Xiaoyi Li Xiaofeng Xu 《Advanced functional materials》2021,31(7):2008681
Solar-driven interfacial evaporation is an emerging technology with a strong potential for applications in water distillation and desalination. However, the high-cost, complex fabrication, leaching, and disposal of synthetic materials remain the major roadblocks toward large-scale applications. Herein, the benefits offered by renewable bacterial cellulose (BC) are considered and an all-cellulose-based interfacial steam generator is developed. In this monolithic design, three BC-based aerogels are fabricated and integrated to endow the 3D steam generator with well-defined hybrid structures and several self-contained properties of lightweight, efficient evaporation, and good durability. Under 1 sun, the interfacial steam generator delivers high water evaporation rates of 1.82 and 4.32 kg m−2 h−1 under calm and light air conditions, respectively. These results are among the best-performing interfacial steam generators, and surpass a majority of devices constructed from cellulose and other biopolymers. Importantly, the first example of integrating solar-driven interfacial evaporation with water wave detection is also demonstrated by introducing a self-powered triboelectric nanogenerator (TENG). This work highlights the potential of developing biopolymer-based, eco-friendly, and durable steam generators, not merely scaling up sustainable clean water production, but also discovering new functions for detecting wave parameters of surface water. 相似文献
88.
Virtual Reality - Virtual reality (VR) is a promising tool and is increasingly used in many different fields, in which virtual walking can be generalized through detailed modeling of the physical... 相似文献
89.
Composites of linear low‐density poly(ethylene‐co‐butene) (PE) or maleated linear low‐density poly (ethylene‐co‐butene) (M‐PE) and cellulose (CEL), cellulose acetate (CA), cellulose acetate propionate (CAP), or cellulose acetate butyrate (CAB) were prepared in an internal laboratory mixer with 20 wt % polysaccharide. The structure and properties of the composites were studied with tensile testing, dynamic mechanical thermal analysis, differential scanning calorimetry, extraction with a selective solvent, Raman spectroscopy, and X‐ray diffraction. Composites prepared with M‐PE presented yield stress and elongation values higher than those of composites prepared with PE, showing the compatibilizer effect of maleic anhydride. Dynamic mechanical thermal analysis performed for M‐PE–CEL, M‐PE–CA, M‐PE–CAP, and M‐PE–CAB composites showed one glass‐transition temperature (Tg) close to that observed for pure M‐PE, and for M‐PE–CAP, another Tg lower than that measured for the polysaccharide was observed, indicating partial mutual solubility. These findings were confirmed by the extraction of one phase with a selective solvent, gravimetry, and Raman spectroscopy. X‐ray diffraction showed that the addition of CEL, CA, CAP, or CAB had no influence on the lattice constants of PE or M‐PE, but the introduction of the reinforcing material increased the amorphous region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:402–411, 2007 相似文献
90.
Essi Pöyry Petri Parvinen Tuuli Malmivaara 《Electronic Commerce Research and Applications》2013,12(4):224-235
Companies’ Facebook pages have emerged as a commonly used marketing channel and their importance as a sales channel is likely to increase. Details about consumers’ underlying motivations to use these pages need to be linked to their effect on the host company’s business. This study distinguishes between consumers’ hedonic and utilitarian motivations for using company-hosted Facebook pages and relates them to two types of community usage behavior: browsing and participation. The effects on variables closely linked to business performance are examined. Analysis of data collected from 1162 members of a travel agency’s Facebook page reveals that hedonic motivations indicate a higher propensity to participate in the community whereas utilitarian motivations relate more strongly to merely browsing the community page. The participating members, however, do not show intentions to buy from the host company or refer it to others, while the browsers do. For practitioners, the finding that hedonic community participants are needed to maintain the community, but that they are unlikely to profit the company, is crucial. 相似文献