摘要 :
In the nine years since its establishment in 1988, the Intergovernmental Panel on Climate Change (IPCC) has attempted to walk the tightrope of being scientifically sound and politically acceptable. This paper investigates how the ...
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In the nine years since its establishment in 1988, the Intergovernmental Panel on Climate Change (IPCC) has attempted to walk the tightrope of being scientifically sound and politically acceptable. This paper investigates how the IPCC has evolved over two assessment cycles. It provides an in-depth examination of important characteristics of the IPCC process including the peer review mechanism, participation of developing countries, and its interactions with the intergovernmental negotiation process on climate change.
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摘要 :
Climate change is a problem which is global both in terms of causes and consequences. The uncertainties are large and likely to persist. Meanwhile, the political and economic stakes of both action and inaction are much higher than...
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Climate change is a problem which is global both in terms of causes and consequences. The uncertainties are large and likely to persist. Meanwhile, the political and economic stakes of both action and inaction are much higher than those in other transboundary concerns such as acid rain and ozone depletion. The public policy impact of scientific opinions on climate change, therefore, not only depends upon what is being said, but also, who is advancing those conclusions and how they were arrived at. This was the rationale behind the setting up of the Intergovernmental Panel on Climate Change (IPCC) in 1988. The paper examines the IPCC in the context of prior assessment efforts. It attempts to unravel the processes which caused the IPCC to be set up when it was and how it was, as opposed to different times and different forms.
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摘要 :
The charge motion in a tumbling mill is analyzed in detail using a numerical simulation scheme known as the discrete element method (DEM). In particular, the profile of the ball charge, impact energy distribution and power draft a...
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The charge motion in a tumbling mill is analyzed in detail using a numerical simulation scheme known as the discrete element method (DEM). In particular, the profile of the ball charge, impact energy distribution and power draft are predicted as a function of mill operating conditions. The analyses are verified by direct experimentation in a 90-cm diameter ball mill of adjustable length fitted with a transparent end-plate. The images of the charge motion are captured on a video camera and analyzed with image-processing software. Simultaneously, the mill power is recorded with a torque sensor.The DEM prediction of power draw is compared with experimental measurements. Also, predicted charge profiles are compared with video images. Both ball segregation and surging phenomena are analyzed A novel scheme of analyzing video images for obtaining impact energy spectra is shown. In all cases, the results of the numerical scheme are in good agreement with experimental measurements, thereby proving that the three-dimensional numerical code is a viable tool for ball mill analysis.
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