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71.
Bruno Takahashi Kanni Huang Frederick Fico David Poulson 《Environmental Communication: A Journal of Nature and Culture》2017,11(1):106-121
This study focuses on the use of science sources as experts in news stories about climate change coverage in the Great Lakes region of the US and Canada. We examine, using the hierarchy of influences model, whether the use of scientific sources in climate change coverage may be related to factors such as geographic location, reporting frequency, and authorship, in the prestige press as well as regional and local media. The study found that as many or more non-scientists than scientists are selected as sources regardless of geographic location, reporting frequency, or authorship. However, the study also found that the more stories reporters produce on this topic, the more likely their stories are to use and give prominence to science sources. In addition, the articles included few denier sources, but denier views are more likely to appear in a more prominent location in the articles than supporters when stories are framed as conflict over global warming. These results highlight the need for additional research examining the expertise of climate scientists in news stories to better understand news decision-making in the context of complex scientific reporting. 相似文献
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Suzannah Evans 《Environmental Communication: A Journal of Nature and Culture》2016,10(4):492-507
Developing nations have tended to have been overlooked in studies of climate reporting. This study is based upon a content analysis of three daily newspapers in the Philippines to examine climate change coverage compared to reporting by Western wire services. In addition, the study draws on individualist–collectivist theory to theorize about differences in reporting between the Philippine and Western wire sources. Despite the historic influence of the American news system on Philippine journalism, the study finds that Western journalistic norms do not describe Philippine climate reporting well and that Filipino-penned articles are more likely to include the value of collectivism rather than individualism. This suggests that national cultural differences may be reflected in climate reporting. 相似文献
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Luca Catarinucci Luciano Tarricone 《International journal of occupational safety and ergonomics》2013,19(1):45-52
The finite difference time domain method (FDTD) is frequently used for the numerical solution of a wide variety of electromagnetic (EM) problems and, among them, those concerning human exposure to EM fields. In many practical cases related to the assessment of occupational EM exposure, large simulation domains are modeled and high space resolution adopted, so that strong memory and central processing unit power requirements have to be satisfied. To better afford the computational effort, the use of parallel computing is a winning approach; alternatively, subgridding techniques are often implemented. However, the simultaneous use of subgridding schemes and parallel algorithms is very new. In this paper, an easy-to-implement and highly-efficient parallel graded-mesh (GM) FDTD scheme is proposed and applied to human–antenna interaction problems, demonstrating its appropriateness in dealing with complex occupational tasks and showing its capability to guarantee the advantages of a traditional subgridding technique without affecting the parallel FDTD performance. 相似文献
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目的 开展时效过程中61.5%IACS高导耐热铝合金导线析出第二相特性及其电导率与拉伸力学性能变化规律的研究,评价其热稳定性。方法 经过150~230 ℃长达630 h时效,揭示第二相的组成、形态与分布及其对时效态铝合金导线电导率与拉伸力学性能的影响规律。结果 时效态铝合金导线中,颗粒状及针状A13Zr(Y, Er)、A13(Zr(Y)xErl?x)第二相在Al晶内、晶界析出,A13Fe相颗粒弥散分布于Al晶界。伴随着时效过程,铝合金导线的抗拉强度与伸长率先上升、再逐渐下降;同时,铝合金导线的电导率先增大、后逐渐趋于稳定。该趋势随时效温度的升高而越加明显。结论 第二相的析出、长大是影响时效态铝合金导线力学性能及电导率的主要原因。经230 ℃、1 h时效,铝合金导线的强度保持率高达94%,满足GB/T 30551—2014的要求。所有时效态铝合金导线的电导率均高于其初始值,该高导耐热铝合金导线的热稳定性良好。 相似文献
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Ali Vazini Shayan Reza Azar Afza Reza Teimouri 《Journal of Manufacturing Processes》2013,15(4):644-658
This work deals with parametric study of dry wire EDM (WEDM) process of cemented tungsten carbide. Experiments have been conducted using air as dielectric medium to investigate effects of pulse on time, pulse off time, gap set voltage, discharge current and wire tension on cutting velocity (CV) surface roughness (SR) and oversize (OS). Firstly, a series of exploratory experiments were carried out to identify appropriate gas and its pressure. Afterward, preliminary experiments were conducted to investigate effects of process parameters on dry WEDM characteristics and find appropriate ranges for each factor. Then a central composite rotatable method was employed to design experiments based on response surface methodology (RSM). Empirical models were developed to create relationships between process factors and responses by considering to analysis of variances (ANOVA). To increase the predictability of the process, intelligent models have been developed based on back-propagation neural network (BPNN) and accuracy of these models was compared with mathematical models based on root mean square error (RMSE) and prediction error percent (PEP). In order to select optimal solutions in the cases of single-objective and multi-objectives optimization problems, optimization includes two main approaches. First approach was based on mathematical model and desirability function. Also second approach was designed based on neural network and particle swarm optimization. These approaches were applied in both cases of single-objective and multi-objectives optimization problems and their results were compared with together. Results indicated that selection of air at inlet pressure of 1.5 bar is really appropriate for conducting experiments of next stages. Also, the BPNN creates more accurate prediction rather than mathematical model. Moreover, the BPNN-PSO approach was more efficient in optimization of process rather than mathematical model-desirability function in respect with validation tests. 相似文献
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