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31.
32.
D. H. Hall 《Scientometrics》1993,28(3):237-286
Petroleum production and exploration, used as petroleum industry indicators, and accumulation of petroleum-related geoscience literature, used as a science indicator, were compared by several means to gauge the degree of interaction between science and the industry in the period 1934–1990. Methods of comparison employed were: time domain correlations and crosscorrelation; correlations of spectra using coherence and crosspower spectra, and growth-modelling of the indicators. A fifty-year exploration cycle was found, beginning about 1945. Principal features of this cycle seem to coincide with prominent features in the time series for geoscience literature, and both of these variables are correlated with petroleum production. All three variables appear to have been determined ultimately by economic and political events which affected the petroleum industry. All of them show long-period cycles which coincide with the fourth Kondratiev cycle and the beginning of the fifth Kondratiev. The longest time series used (petroleum production in the United States, 1860–1990) shows long-period cycles matching the third, fourth and fifth Kondratiev cycles. 相似文献
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e-Government systems differ from commercial information systems (IS) in that they frequently encompass strategic goals that go beyond efficiency, effectiveness and economy, and include political and social objectives such as trust in government, social inclusion, community regeneration, community well-being and sustainability. Designing e-Government systems that help to meet these objectives is a significant challenge for the future. This paper develops an evaluative design framework for e-Government projects that complements traditional approaches to IS evaluation. The framework is based upon Moor's concept of public value. It focuses upon citizens' and clients' experiences of service provision and service outcomes as contributors to the formation of public trust. Trust is shown to be related to the extent to which people feel that an e-Government service enhances their sense of being well-informed, gives them greater personal control, and provides them with a sense of influence or contingency. The framework's development and validation are founded upon analyses of a two live case studies in south-east England and London, U.K. 相似文献
35.
Higher heating values (HHVs) of fatty acids (C4–C18) were measured and correlated using linear least square regression analysis. Equations were developed for the estimation of the HHVs of saturated fatty acids from their molecular weight (Mw), density (DN) and carbon number (CN). These equations are HHV = 0.0518 Mw + 29.76, HHV = −93.4 DN + 122.67 and HHV = 0.7271 CN + 31.419 with R2 values of 0.9895, 0.9798, and 0.9895, respectively. The correlations may be used for HHV estimation of mixtures of fatty acids developed from vegetable oils. 相似文献
36.
FS Hall 《Canadian Metallurgical Quarterly》1998,12(1-2):129-162
This review examines the consequences of social deprivation on brain chemistry and behavior on rats. Although social deprivation produces wide-ranging behavioral and neurochemical effects, it appears that these effects are determined by a number of factors, the most critical factor being the age or developmental stage during the period of deprivation. Roughly, the effects examined in this review may be separated into three major developmental stages and each is related to deprivation of specific types of social interaction: preweaning/neonatal, postweaning/adolescent, and adult. The effects of social deprivation during each of these stages appears to be neurochemically and behaviorally specific. However, much of the research to date has failed to examine deprivation during specific stages, often combining deprivation of different types. Nonetheless, these modifications of experience produce animals of differing phenotypes, which could be characterized as pathological in nature in many instances, and may model particular aspects of human psychopathologies or perhaps the propensity to develop those phenotypic features. 相似文献
37.
This paper develops a transient thermal model for line traps. The model was incorporated into a computer program that numerically integrates the governing nonlinear differential equation in time to predict critical temperatures and component short and long term ratings for a wide range of operating conditions. The model accounts for many factors including: variable air properties, variable material properties, environmental conditions, and a wide variety of component geometries and orientations. To verify the temperatures predicted by the thermal model, The Georgia Power Research Center carried out an extensive series of indoor laboratory tests to experimentally measure temperatures of energized line traps under transient loading conditions. Model predictions were within 8°C for 75 percent of the data. This paper presents the development of the governing equations and describes in detail the calculation of the convective and radiative components of heat transfer. Comparisons of the model predictions for two different line trap designs in different orientations to experimental data are presented to demonstrate the accuracy and flexibility of the thermal model 相似文献
38.
The production of the cognitive internal state word know by four 2- to 5-year-old children and their parents was examined. The levels of meaning of cognitive words can be categorized hierarchically along the dimensions of conceptual difficulty and abstractness (see Booth & Hall, 1995). The present study found that children and their parents expressed low levels of meaning less frequently, whereas they expressed high levels of meaning more frequently as a function of age. The children's use of know was also correlated positively with (1) their number of different words produced suggesting that cognitive words are related to more general semantic processes, and (2) with parental use of those same cognitive words suggesting that parental linguistic input may be an important mechanism in cognitive word acquisition. Finally, young children tended to use know more to refer to themselves than to refer to others, whereas their parents tended to use know equally to refer to self and others. The importance of cognitive words in a theory of language acquisition is discussed. 相似文献
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40.
L.P. Hall 《Food microbiology》1985,2(1):31-37
A medium giving maximum indole production colonies of Escherichia coli has been defined and includes diethylaminoethylcellulose which restricts the spread of indole through the agar medium. A reagent based on p-dimethylaminocinnamaldehyde has been developed to give optimum indication of indole production. A simple method which will identify E. coli in cultures obtained from selective media is described and an extension, including a resuscitation stage, devised for rapid and direct quantitation of E. coli from frozen foods. 相似文献