関連する実験動画
Updated: Jul 14, 2026
10:03
The Preparation of Electrohydrodynamic Bridges from Polar Dielectric Liquids
Published on: September 30, 2014
チリ南部における最後の氷河期からホロセンの移行期である
K D Bennett1, S G Haberle, S H Lumley
1Quaternary Geology, Department of Earth Sciences, Uppsala University, Villavägen 16, S-752 36 Uppsala, Sweden. Keith.Bennett@geo.uu.se
Science (New York, N.Y.)
|October 13, 2000
まとめ
北大西洋におけるヤング・ドライアス冷却現象は,地球規模の現象ではなかった. チリ南部の新しい証拠は,この冷却は地域的であり,北大西洋地域のみに影響を与えたことを示しています.
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 四次科学とは四次科学である.
- 海洋学 海洋学とは
背景:
- 最後の氷河期の終焉により,北大西洋は著しく温暖化しました.
- この温暖化は,氷河活動が再開した時期であるヤング・ドライアス・クロノゾーン (YDC) によって中断された.
- YDCの冷却のグローバルまたは地域的な性質は,古気象学における重要な問題である.
研究 の 目的:
- ユング・ドライアスの冷却現象が世界的な現象であったか,北大西洋地域に限定されていたかを調査する.
- YDC中に南半球の古気候を再構築する.
主な方法:
- 年代,堆積物,古生態学的記録の分析.
- チリ南部の小湖から採取した堆積物分析.
主要な成果:
- チリ南部の堆積物記録は,若いドライアスのクロノゾーン中に冷却の証拠を示さない.
- これは,南太平洋の地表水域に重大な冷却が欠けていることを示しています.
結論:
- ユング・ドライアスの冷却現象は,地域的な現象であり,主に北大西洋に影響を与えた.
- この発見は,YDCに関するグローバルな説明に異議を唱え,北大西洋を中心としたメカニズムを支持している.
関連する概念動画
01:23States of Water
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
02:39Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
02:33Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
03:12Freezing Point Depression and Boiling Point Elevation
Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
01:24Freezing Point Depression and Boiling Point Elevation
When a non-volatile solute is added to a pure solvent, it results in the lowering of the freezing point of the solvent. This phenomenon is called freezing point depression. The extent to which the freezing point is lowered depends on the molality of the solute -the number of moles of solute per kilogram of solvent and the cryoscopic constant of the solvent.From the plot of chemical potential, μ, against temperature, it is evident that the μ of both solid and liquid solvents decrease with...
01:28Transition Zone
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...