Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Distribution of dissolved organic matter in the Pearl River Estuary, China

Chromophoric dissolved organic matter (CDOM) fluorescence and dissolved organic carbon (DOC) were measured in the Lingdingyang Estuary, a major component of the Pearl River Delta, China, in May 2001 and November 2002. Measurements of CDOM and DOC suggest multiple sources of dissolved organic matter (DOM) in the low-salinity region of the estuary, due to the mixing of four freshwater outlets, Humen, Jiaomen, Honqimen and Hengmen, all with different freshwater endmembers and all flowing into the head of the Lingdingyang. Our 2002 cruise expanded efforts to characterize these four major outlets, allowing for the quantification of CDOM inputs within this complex watershed. DOC and CDOM appear conservative in mid-salinity (5-20) waters, suggesting that mixing dominates production and removal processes over time scales on the order of 3 days, the residence time of water in this region of the estuary. DOC and fluorescence are linearly correlated in the mid-salinity region of the estuary north of Shenzhen, suggesting that in this region, terrestrial inputs dominate both signals. However, this relationship does not continue out onto the shelf, where water masses of differing optical properties mix. The CDOM/DOC ratio decreases with increasing salinity as would be expected through phototrasformation of CDOM into non-fluorescent DOC. Additionally, this ratio at low salinity appears to vary seasonally, with a higher value in Spring (high flow) compared to Fall (low flow). (C) 2004 Elsevier B.V. All rights reserved

Distribution of dissolved organic matter in the Pearl River Estuary, China

Chromophoric dissolved organic matter (CDOM) fluorescence and dissolved organic carbon (DOC) were measured in the Lingdingyang Estuary, a major component of the Pearl River Delta, China, in May 2001 and November 2002. Measurements of CDOM and DOC suggest multiple sources of dissolved organic matter (DOM) in the low-salinity region of the estuary, due to the mixing of four freshwater outlets, Humen, Jiaomen, Honqimen and Hengmen, all with different freshwater endmembers and all flowing into the head of the Lingdingyang. Our 2002 cruise expanded efforts to characterize these four major outlets, allowing for the quantification of CDOM inputs within this complex watershed. DOC and CDOM appear conservative in mid-salinity (5-20) waters, suggesting that mixing dominates production and removal processes over time scales on the order of 3 days, the residence time of water in this region of the estuary. DOC and fluorescence are linearly correlated in the mid-salinity region of the estuary north of Shenzhen, suggesting that in this region, terrestrial inputs dominate both signals. However, this relationship does not continue out onto the shelf, where water masses of differing optical properties mix. The CDOM/DOC ratio decreases with increasing salinity as would be expected through phototrasformation of CDOM into non-fluorescent DOC. Additionally, this ratio at low salinity appears to vary seasonally, with a higher value in Spring (high flow) compared to Fall (low flow). (C) 2004 Elsevier B.V. All rights reserved

Effects of an estuarine plume-associated bloom on the carbonate system in the lower reaches of the Pearl River estuary and the coastal zone of the northern South China Sea

We observed a phytoplankton bloom downstream of a large estuarine plume induced by heavy precipitation during a cruise conducted in the Pearl River estuary and the northern South China Sea in May-June 2001. The plume delivered a significant amount of nutrients into the estuary and the adjacent coastal region, and enhanced stratification stimulating a phytoplankton bloom in the region near and offshore of Hong Kong. A several fold increase (0.2-1.8 mu g Chl L-1) in biomass (Chl a) was observed during the bloom. During the bloom event, the surface water phytoplankton community structure significantly shifted from a pico-phytoplankton dominated community to one dominated by microphytoplankton (> 20 mu m). In addition to increased Chl a, we observed a significant drawdown of pCO(2) , biological uptake of dissolved inorganic carbon (DIC) and an associated enhancement of dissolved oxygen and pH, demonstrating enhanced photosynthesis during the bloom. During the bloom, we estimated a net DIC drawdown of 100-150 mu mol kg(-1) and a TAlk increase of 0-50 mu mol kg(-1). The mean sea-air CO2 flux at the peak of the bloom was estimated to be as high as similar to-18 mmol m(-2) d(-1). For an average surface water depth of 5 m, a very high apparent biological CO2 consumption rate of 70-110 mmol m(-2)d(-1) was estimated. This value is 2-6 times higher than the estimated air-sea exchange rate. Crown Copyright (c) 2008 Published by Elsevier Ltd. All rights reserved

Towards a Confucian geopolitics

In this article, we argue that Confucian philosophies are vital to understanding contemporary Chinese geopolitics. Existing Western geopolitical frameworks, we contend, are insufficient for grasping the complex theories and historical legacies that underpin China’s foreign policy. This issue becomes particularly salient as scholars and the public alike try to manage complex and changing geopolitical ideas underpinning the Belt and Road Initiative, recently heralded by the Chinese state and epitomising China’s ambition for expanded global engagements. This article provides a much-needed critical assessment and review of Confucian ideas and their uptake in Chinese state theory, geographical imaginations, and geopolitical scripts. While Confucianism typically focuses on ideals of harmony, hierarchy, and normative social order, geopolitics analyses geographical influences on politics – in particular, violence and conflict. However, it is precisely within this contradictory dialectic that new possibilities for analysing the geopolitics of a rising global power can emerge