相关实验视频

Updated: May 22, 2025

A Technical Perspective in Modern Tree-ring Research - How to Overcome Dendroecological and Wood Anatomical Challenges
09:33

A Technical Perspective in Modern Tree-ring Research - How to Overcome Dendroecological and Wood Anatomical Challenges

Published on: March 5, 2015

29.0K

源水和糖的季节性趋势相反,抑制了树环氧同位素的年内变化

Paul Szejner1, Yu Tang1,2, Charlotte Angove1

  • 1Stable Isotope Laboratory of Luke (SILL), Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790, Helsinki, Finland.

The New phytologist
|May 20, 2025
PubMed
概括

树环中的季节性氧同位素变化 (δ18O) 受水源和湿度的影响. 同位素交换过程显著抑制了这些信号,改善了气候重建和了解树木生理学.

关键词:
北极森林是北极森林中的一个.高分辨率的树枝年代学.针头糖是一种糖.叶囊糖类是叶囊糖的类型.在光合作用后的分化过程中.代理人记录的是代理人的记录.稳定的同位素是稳定的.

更多相关视频

Advanced Workflow for Taking High-Quality Increment Cores - New Techniques and Devices07:40

Advanced Workflow for Taking High-Quality Increment Cores - New Techniques and Devices

Published on: March 10, 2023

1.9K
The Calibration and Use of Capacitance Sensors to Monitor Stem Water Content in Trees08:31

The Calibration and Use of Capacitance Sensors to Monitor Stem Water Content in Trees

Published on: December 27, 2017

12.4K

相关概念视频

Global Climate Change01:50

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.
24.0K
The Water Cycle01:00

The Water Cycle

The Earth’s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, the cycling of water is extremely important to ecosystem dynamics.
24.0K
Adaptations that Reduce Water Loss01:57

Adaptations that Reduce Water Loss

Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
25.0K
Oxygen Transport in the Blood01:27

Oxygen Transport in the Blood

Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...
2.3K
The Calvin Benson Cycle01:46

The Calvin Benson Cycle

Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
4.4K
Arrhenius Plots02:34

Arrhenius Plots

The Arrhenius equation relates the activation energy and the rate constant, k, for chemical reactions. In the Arrhenius equation, k = Ae−Ea/RT, R is the ideal gas constant, which has a value of 8.314 J/mol·K, T is the temperature on the kelvin scale, Ea is the activation energy in J/mole, e is the constant 2.7183, and A is a constant called the frequency factor, which is related to the frequency of collisions and the orientation of the reacting molecules.
38.1K