相关实验视频
Updated: Jul 30, 2026

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Resurrection of Dormant Daphnia magna: Protocol and Applications
Published on: January 19, 2018
亚热带北大西洋温度6万到3万年前6万到3万年前
1Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, USA.
概括
北萨尔加索海的海面温度在6万至3万年前大幅波动. 这些亚热带气候变化反映了高度地区的变化,表明了相关的气候动态.
科学领域:
- 古气候学 古气候学
- 海洋学 海洋学 海洋学
- 气候科学 气候科学
背景情况:
- 了解过去的气候变化对于预测未来的气候变化至关重要.
- 高度气候事件与亚热带气候变化有关,但这种关系的精确性质需要进一步调查.
研究的目的:
- 在地球气候历史的关键时期重建亚热带海洋表面温度 (SSTs).
- 研究亚热带气候变化与高度气候事件之间的相关性.
主要方法:
- 在百慕大利用了基不和比率,起沉积物核心以重建过去的SST.
- 建立了详细的古气候记录,从6万年前到3万年前.
主要成果:
- 在北萨尔加索海中记录了SST反复波动的2-5°C.
- 观察到这些亚热带温度变化与从格陵兰冰芯推断出的高度温度之间的强烈共变.
- 在特定的阶段间时期,确定了3-5°C的突然冷逆转,持续时间不到250年.
结论:
- 亚热带地区最大的变暖事件在规模上与冰川-全新世纪变暖相美.
- 这些发现表明,快速的亚热带变暖事件本质上是不稳定的,容易发生突然的冷却逆转.
- 这凸显了全球气候系统的相互联系,以及响应高度强迫的快速转变的潜力.
相关概念视频
What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
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Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
Effects of Temperature on Free Energy
The spontaneity of a process depends upon the temperature of the system. Phase transitions, for example, will proceed spontaneously in one direction or the other depending upon the temperature of the substance in question. Likewise, some chemical reactions can also exhibit temperature-dependent spontaneities. To illustrate this concept, the equation relating free energy change to the enthalpy and entropy changes for the process is considered:
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Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
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Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...
Oxygen
Atmospheric air is only about 20 percent oxygen, but that oxygen is a key component of the chemical reactions that keep the body alive, including the reactions that produce ATP. Brain cells are susceptible to a lack of oxygen because they require a...

