相关实验视频
Updated: Jul 13, 2025

09:10
Fabrication and Testing of Microfluidic Optomechanical Oscillators
Published on: May 29, 2014
12.2K
通过减少真空中的机械和热损失来进行加热流体共振器的先进操作
Juhee Ko1, Bong Jae Lee1, Jungchul Lee1
1Department of Mechanical Engineering, Center for Extreme Thermal Physics and Manufacturing, Korea Advanced Institute of Science and Technology (KAIST), 34141 Daejeon, Korea.
Microsystems & nanoengineering
|October 13, 2023
概括
研究人员增强了加热流体共振器 (HFR) 以精确测量小液体体积的热物理测量. 通过减少真空中的热损失,对热导率和特定热量的测量灵敏度显著提高.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
背景情况:
- 对超小液体体积的同时和定量热物理测量具有挑战性.
- 热流体共振器 (HFRs) 已先前开发用于此类测量.
- 提高HFR的精度需要将热损失降至最低.
研究的目的:
- 为了提高加热流体共振器 (HFR) 的精度,用于热物理测量.
- 为了减少HFR中传感元件周围的热损失.
- 为了提高导热率和特定热量的测量灵敏度.
主要方法:
- 定制制造的真空室具有光学,电气和微流体接入.
- 在10-4 mbar条件下减少了两个数量级的对流损失.
- 使用HFR进行热物理性质测量.
主要成果:
- 导热度的测量灵敏度增加了4.1倍.
- 特定热容量的测量灵敏度增加了1.6倍.
- 信号与噪声比用于区分H2O和D2O,增加了9倍 (导热率) 和5倍 (特定热容量).
结论:
- 增强真空的HFR系统显著提高了超小液体体积的热物理测量的精度.
- 减少热损失对于提高测量灵敏度至关重要.
- 改进的HFR可以有效地区分具有相似性质的液体,如H2O和D2O.
相关概念视频
Mechanisms of Heat Transfer II
3.3K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.3K
Mechanisms of Heat Transfer I
4.3K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
4.3K
Mechanisms of Heat Transfer
339
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
339
Mechanism of heat transfer
1.2K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.2K
The Carnot Cycle
2.9K
Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics.
What could be the theoretical limit to the efficiency of a heat engine? The...
What could be the theoretical limit to the efficiency of a heat engine? The...
2.9K
Joule-Thomson Effect
4.2K
The Joule-Thomson effect, also known as the Joule-Kelvin effect, describes the temperature change of a fluid when it is forced through a valve or porous plug while keeping it in a thermally insulated environment. This experiment is called a throttling process. This is an important effect widely used in refrigeration and the liquefaction of gases.
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
4.2K

