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51.
The simultaneous influence of increasing oil scarcity, greenhouse gas control and renewable energy targets will result in a future of sustained energy prices. Whether modern economies can find a smooth path away from fossil fuels is a fundamental socio-economic and political question, which according to standard economics depends to a large extent on the degree of substitution between energy and capital. We study this issue by modelling the manufacturing sector with a translog cost function in seven OECD countries using the EU-KLEMS database for the period 1970–2005. After a literature survey, different production structures accounting for input substitution, returns to scale and technical change are estimated, and substitution elasticities are derived. Our results indicate a general complementarity or weak substitution relationship between energy and capital, suggesting that an increase in energy price, e.g. due to climate policy or scarcer fossil fuels, will likely reduce capital inputs, which might lead to a lower output of manufacturing. 相似文献
52.
53.
Rizza G Attouchi F Coulon PE Perruchas S Gacoin T Monnet I Largeau L 《Nanotechnology》2011,22(17):175305
We have studied how spherical 23 ± 3 nm Au(45)Ag(55) nanoparticles embedded within a silica matrix transform into prolate nanorods and nanowires by irradiating them with swift heavy ions. Samples were irradiated at room temperature and normal incidence with 74 MeV Kr and 36 MeV S ions for fluences up to 1.0 × 10(15) cm(-2). We demonstrate the existence of two regimes: (i) below a critical fluence, ~ 2.0 × 10(14) cm(-2), the transformation of the spherical nanoparticle into a nanorod is an individual process, i.e. each nanoparticle transforms into a single nanorod; (ii) for larger fluences the transformation from nanorod to nanowire becomes a collective process, i.e. the break up and dissolution of unstable nanorods contribute to the growth of long nanowires. The passage from the first to the second regime can be interpreted in terms of a Rayleigh-like instability under irradiation. The latter becomes active when the diameter of the nanowire approaches its saturation width under irradiation. Furthermore, we show that the composition of the alloy is only slightly modified during the ion-shaping process. Finally, the energy and the fluence thresholds for deformation and the deformation strain-rate are estimated. 相似文献
54.
Palmira Mazzaracchio Piergiorgio Pifferi Maddalena Kindt Athanase Munyaneza & Giancarlo Barbiroli 《International Journal of Food Science & Technology》2004,39(1):53-59
The interactions between different glucosidic anthocyanins (pelargonin, cyanin, delphinin, malvin and petunin) and some organic compounds (lactic, galacturonic, tannic, phenolic and sinapic acids; pyrogallol, furfural, pectin, cellulose, hydrolitic lignin) which are present in food‐stuffs were investigated at pH 3.0–4.3 and 25 °C. The interactions were monitored by means of u.v.‐VIS spectra and their different behaviours were highlighted by following changes in absorbance over a range of wavelengths (Δλ and ΔA). Significant effects on absorbance were detected and are discussed in terms of the phenomenon of co‐pigmentation. 相似文献
55.
P systems and Brane calculi are two (families of) computational models inspired by the structure and the functioning of living cells. Although they have different goals there is a recent growing of interests in results that bridge the two research areas.Here we consider an important kind of communication based on the natural budding of mobile membranes (e.g., Golgi apparatus) that is already defined for P systems and we show how to construct an analogous communication in the basic Phago/Exo/Pino Brane calculus. 相似文献
56.
In spite of cancer screening programs, women continue to present with advanced breast cancer. How do women decide whether and when to seek an evaluation for self-discovered symptoms? This study examined 104 narratives told by 80 Anglo-, Latina-, and African-American women who participated in 1 of 16 community-based focus groups. The women's narratives contained powerful thematic messages about breast cancer and their expected behavior in the event of a self-discovered breast symptom. Narrative explanations that predicted an increased likelihood of advanced disease at diagnosis included these factors: incorrect symptom attributions and risk estimations; reluctance to consider the threat posed by the symptom; failure to tell another person about the symptom; and expectations of abandonment by male partners, deportation, prejudice, and refusal of treatment due to poverty. Stories of advanced breast cancer also told of reliance on alternative healing, concerns about overwhelming family resources, and extreme modesty that inhibited obtaining a physical examination. Interventions aimed at earlier detection of breast cancer must connect with the beliefs and assumptions embedded in these narratives, provide pragmatic solutions for perceived constraints on seeking evaluations of self-discovered symptoms, and explore the use of community narratives to confirm the value of early detection of breast cancer. 相似文献
57.
Efficient removal of lymphocytes undergoing programmed cell death (apoptosis) by macrophages plays an important role for the proper function of normal immune system. Furthermore, in malignant lymphoma, elimination of apoptotic tumor cells by phagocytes contributes to the anti-tumor immune response. It is unknown, however, whether macrophages in normal and malignant lymphoid tissues differ in their ability to recognize and remove apoptotic cells. Our present results demonstrate that normal and malignant lymphoid tissues differ according to the extent of the infiltration by macrophages. The highest densities of macrophages (p < 0.0001) were detected in diffuse large B-cell lymphoma, centroblastic (DLBCL-CB) and immunoblastic variants and Burkitt's lymphoma. The grade of the macrophage infiltration correlated with the proliferation rates of the tumors (p < 0.0001). Compared with normal lymphoid organs, malignant lymphoma contained lower percentages of apoptotic cells phagocytosed by tissue macrophages (p < 0.001). Of all lymphomas tested, mantle cell lymphoma and DLBCL-CB expressed the lowest percentages of phagocytosed apoptotic cells (p < 0.0001). 相似文献
58.
Giancarlo Scalabrin Giovanni Cristofoli Maurizio Grigiante 《Chemical Engineering Communications》2002,189(12):1705-1729
Predictive and semipredictive models for viscosity calculation are currently needed and highly appreciated. Models developed for halogenated refrigerants (HR) and based on Corresponding States (CS) are leading to a prediction accuracy comparable to that of specifically developed models. In the present work, using recently published, highly accurate viscosity dedicated equations, it has been verified that viscosity conforms to a two-parameter CS model is then developed, based on Teja and coworker's three-parameter CS structure. Two fluids of the same family are taken for reference, and the reduced viscosity of a third fluid is obtained in reduced P,T variables. At first the Pitzer acentric factor is proposed as a third parameter, then it is substituted with a temperature-dependent function fitted on saturated viscosity data. The prediction accuracy of the model is comparable to that of the reference fluid equations and, considering its predictive nature, it is a satisfactory tool for the needs of technical applications. 相似文献
59.
Because of the progress in electronic technology and the increasing importance of colour quality control in various branches of industry, over the last decades several colour-measuring instruments have been developed, each one with its own design features; the lack of standardization among them might be an obstacle to the spread of colour quality control as a means for product qualification. Colour-difference measurements taken with 11 different models of spectrophotometers [four with 45 (circumferential)/0 geometry and the others with diffuse geometry] were compared with the aim of analyzing their correlation and dispersion. In order to cover different colour-space regions, measurements were taken on test panels painted with four saturated basic hue (red, yellow, green, and blue) acrylic products gradually modified by adding white or black paint. Basic statistical analyses made on colour-difference values (ΔE*ab, ΔL*, Δa*, and Δb*) resulted in a high correlation among the examined instruments, but a certain variability, particularly as far as certain hues are concerned. 相似文献
60.
Camponeschi Biagio Casa De Giancarlo Giglio Giovanni Mattias Pier Paolo 《Bulletin of Engineering Geology and the Environment》1984,29(1):21-25
Close to the present Latium coast, at Rio Torto, in the area between Pomezia and Ardea, about 35 km to the South of Rome, there are vast sandy deposits of continental and marine origin that may be associated with ancient coast lines. The extent and thickness of these deposits vary widely and are used as sources for extracting aggregate materials that are successfully used in preparing cement mortars. Field surveys and laboratory tests have helped identify these products as belonging to a paleogeographic environment and to define both their volume and their geographic location. The results obtained have allowed characterization of the sands from a technical point of view and to define their fields of utilization keeping account of their location and their mining availability. 相似文献