【阅读】2019/09/27起约堵整理（10/11日更新，51篇原始，48篇考古）

Florrra

求更新~

Ann5778

谢谢

aaayao

感谢分享！               

killuacx

这次又重酷了是吧

clz123134

13. Pluto冥王星那篇疑似改写自：
https://www.bbc.com/news/science-environment-33462184

billyisfragile!

JOURNAL ARTICLE
Probing the Depths of Crater Lake: During much of its 100 years of National Park status, this national treasure saw little scientific study, despite significant environmental threats
Douglas W. Larson
American Scientist
Vol. 90, No. 1 (JANUARY-FEBRUARY 2002), pp. 64-71
Published by: Sigma Xi, The Scientific Research Honor Society
Stable URL: http://www.jstor.org/stable/27857598
Page Count: 8

Probing the Depths of Crater Lake
During much of its 100 years of National Park status, this national treasure saw little scientific study, despite significant environmental threats
Douglas W. Larson


Nitrogen: An Alternative Hypothesis


还有一篇挺长的 说是水里的nitrogen和xxx(应该是种植物) abundance对水质的影响 说了两种theory
第一种是由于人类污染和超过10倍nitrogen废水排放
第二种是说一个upwelling process 把水底的nitrogen搅上来 主旨应该是present two theories


During the lengthy debate over sewage contamination and its effects on the lake, alternative hypotheses were sought to explain how other sources of nitrogen might stimulate excess phytoplankton production. One theory argued that nitrogen from remineralized organic matter on the lake bottom is circulated into the euphotic zone by convection. This process of nitrogen upwelling is driven by warm, chemically concentrated waters emanating from active hydrothermal vents on the lake bottom. Hydrothermal fluids warm the lake’s deep waters, causing them to convect, which mixes the lake vertically while transporting nutrients and other dissolved chemicals toward the lake surface.


The presence of active lake-bottom hydrothermal vents was first proposed in 1968 by A. S. Van Denburgh of the US. Geological Survey. Active vents, according to Van Denburgh, accounted for the lake’s relatively high sulfate and chloride concentrations, averaging 10.5 and 10.2 milligrams per liter, respectively. In 1983, David Williams of the US. Geological Survey and Richard Von Herzen of Woods Hole Oceanographic Institution measured conductive heat flow through lake-bottom sediments, concluding that heat flow into the lake causes deep waters to convect slowly. They also estimated that lake-bottom thermal springs (they discovered two) discharged 6.35 x 109 grams of dissolved solids into the lake annually.


In 1988 and 1989, oceanographers Robert Collier and Jack Dymond of Oregon State University explored the bottom of Crater Lake in the submersible Deep Rover (Figure 9), making a total of about 50 dives. They discovered evidence of hydrothermal venting, including: higher temperature and salinity gradients extending several meters upward from the lake bottom; prolific mats of chemolithotrophic bacteria (Figure 10), whose interstitial water temperatures exceeded the temperature of ambient lake-bottom water by more than 15 degrees; and brine pools on the lake bottom that were about 10 times more chemically concentrated than ambient water. They concluded that upwelling of nitrate-nitrogen from deep waters contributes more than 85 percent of the total new nitrogen entering the lake’s euphotic zone, with the balance derived from allochthonous (outside the lake) sources, such as direct precipitation and watershed runoff. If correct, then perhaps the nitrogen derived from sewage would not have been a significant nutrient source for phytoplankton.

billyisfragile!

clz123134 发表于 2019-10-2 14:12
13. Pluto冥王星那篇疑似改写自：
https://www.bbc.com/news/science-environment-33462184

https://forum.chasedream.com/for ... amp;fromuid=1333346

billyisfragile!

Despite its seemingly mundane status, food preparation takes on a political dimension because women’s ability to produce food and drink becomes critical to a household’s ability to fulfill its obligation to society, often in the form of ritual feasts or tribute owed to political leaders (37, 38, 40, 41). Brumfiel (13) has looked at how food habits changed in the Valley of Mexico under Aztec rule (after AD 1430) as tribute demands increased. She argued that tortillas became relatively more important in the daily diet at the expense of stews or corn porridge. This change in food habits increased work for women because tortillas take much longer to prepare and cook. But the end results were foods that were more transportable, allowing household members to work away from home more easily. Women also changed their activities in the Mantaro Valley, Peru, as independent groups came under Inca control in the fifteenth century AD. Hastorf drew on paleoethnobotanical remains to argue that after the Inca conquest women spent more time making corn beer, which was used as a social emollient in the feasts sponsored by the state to feed its subjects paying their tribute in the form of labor. Stable isotope analysis of skeletons, however, indicates that during this same period women’s diet was lower in corn than men’s, which suggests that they were less likely to participate in these feasts.

YYLeo

为什么看不到附件呀？

去去黎

还是老规矩？要说谢谢？