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您的检索式：作者名="Robert W.Howarth"
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| 1 | 美国1961~2000年氮使用量的变化及未来趋势预测显示文摘从1961~1997年,因人类活动而输入到美国的氮翻了一番,特别是在上个世纪60年代和70年代,其增长量最大。尽管无机氮肥的使用量增长最大,但矿物燃料燃烧所造成的NO_x排放,也有明显的增加。1961年,美国农业生产系统中的生物固氮量是活性氮的最大来源;到了1997年,尽管生物固氮量也有增加,但相比而言,无机氮肥的使用和NO_x的排放增加得更快,成为两个最大的氮源。1961~1997年,在输入到美国的活性氮中,有2/3发生了脱氮反应或者是被贮存在土壤与生物群落之中,有1/3输出到境外。在输出到境外的这部分氮中,通过河流流到海洋中的分量最大,其次是通过粮食和饲料出口而到其它国家以及通过大气平流传输到了海洋中。动物性蛋白的消费是美国农业系统中氮使用的主要驱动因子,如果饮食方式或农业生产方式不发生改变,在来来30年的时间里,美国肥料的使用量将继续增长,流向海洋中的氮通量将可能再增长30%,但也有可能出现下降。 | Robert W.Howarth Elizabeth W.Boyer Wendy J.Pabich James N.Galloway 闵庆文 | 2002 | AMBIO-人类环境杂志2002，31，2： | 9 |
| 2 | The development of policy approaches for reducing nitro-gen pollution to coastal waters of the USA显示文摘Two-thirds of the coastal rivers and bays in the United States are degraded from nutrient pollution, and nitrogen inputs these waters continue to increase. The nitrogen comes from a variety of sources, including runoff from agricultural fields, concentrated animal feeding operations, atmospheric deposition from fossil fuel combustion, and sewage and septic wastes.Technical solutions for nitrogen pollution exist at reasonable cost. That most of these solutions have not yet been implemented to any significant extent across the United States suggests that new policy approaches are necessary. The best solution may involve a combination of voluntary and mandatory approaches, applying different approaches to different sources of nitrogen poilution. A watershed-based approach that relies heavily on voluntary mechanisms (such as crop-yield insurance to reduce over-fertilization) is likely to be the most effective for some sources of nitrogen (such as runoff from agricultural fields), while a uniform national regulatory approach may be better for others (such as NOx emissions from fossil fuel combustion). Implementation of management strategies should be carefully coupled to monitoring programs to assess the effectiveness of these strategies. While both nitrogen and phosphorus are important to control, the focus should be on nitrogen management, in part because nitrogen is more generally the causal agent of coastal eutrophication. Also, while nitrogen-control practices tend to also reduce phosphorus pollution, phosphorus-control practices often have little effect on nitrogen.Although current scientific and technical knowledge is sufficient to begin to make substantial progress toward solving coastal nitrogen pollution, progress will be made more quickly and more cost effectively with increased investment in appropriate scientific research. | Robert W.Howarth | 2005 | Science China(Life Sciences)2005，48，z2： | 3 |
| 3 | Share Promising Ideas,Explore New Frontiers显示文摘The ocean is the foundation of life and plays a key role in the Earth’s changing climate and ecosystem,but its vast span and complex workings are still far from being fully explored.Oceanography is intrinsically a multidisciplinary science,aiming at understanding the physical,biological,chemical,and geological processes in the ocean,as well as the interactions among them. | Dake Chen Robert W.Howarth | 2022 | Ocean-Land-Atmosphere Research2022，1，1： | 0 |
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