相关实验视频
Updated: Jul 11, 2026

11:15
Determining the Contribution of the Energy Systems During Exercise
Published on: March 20, 2012
概括
这项研究通过包括劳动力和政府服务的能源来重新评估体现的能源计算. 包括这些因素揭示了产品体现的能量与其在美国经济中的美元价值之间的强烈联系.
科学领域:
- 环境经济学环境经济学
- 能源分析 能源分析
- 输入-输出经济学 输入-输出经济学
背景情况:
- 嵌入式能源量化了生产商品和服务的总能量.
- 传统的计算通常不包括劳动力和政府服务的能源投入.
- 这种排除源于假设独立的经济生产因素 (土地,劳动力,资本).
研究的目的:
- 调查包括劳动力和政府服务能源在体内能源计算中的影响.
- 为了确定是否包括这些以前遗漏的能源投入,加强了体现的能源和经济价值之间的关系.
主要方法:
- 调整了输入-输出分析,以纳入劳动力和政府服务的能源需求.
- 使用修订后的方法计算了92个部门的美国经济的体内能量.
主要成果:
- 包括劳动力和政府服务的能源在内,显著影响了体现的能源计算.
- 当这些因素被纳入时,体现的能量和美元价值之间观察到强烈的相关性.
- 强调了经济生产因素的相互依赖,特别是能源的作用.
结论:
- 标准的嵌入式能源评估可能会低估总能源消耗,忽略了劳动力和政府服务能源.
- 经济生产因素不是独立的,能源是它们的组成部分.
- 修订后的嵌入式能源计算提供了更准确的经济价值和能源强度的表示.
相关概念视频
Energy Budgets and Reproductive Strategies
Organisms must balance energy intake with the energy required for growth, maintenance, and reproduction. These trade-offs result in a variety of survivorship and reproductive strategies, including semelparity and iteroparity. Semelparous species reproduce only once in their lifetime, often investing most available resources into that single reproductive event. Iteroparous species, by contrast, reproduce multiple times over their lifetimes, typically allocating fewer resources to any single...
Energy
The universe is composed of matter in different forms, and all forms of matter contain energy. The different forms of energy on Earth originate from the Sun—the ultimate energy source. For instance, plants capture light energy from the Sun, and through the process of photosynthesis, convert it into chemical energy. This stored energy from plants can be harnessed in many ways. For example, eating plant products as food provides energy for our body to function, and burning wood or coal...
Work-energy Theorem
According to Newton’s second law of motion, the sum of all the forces acting on a particle (net force) determines the rate of change in the momentum of the particle (motion). Therefore, we should consider the work done by all forces acting on a particle, or the net work, to see its effect on the particle’s motion.
The work-energy theorem equates work done by all the forces on an object to the change in its kinetic energy. The theorem can be used to calculate work done by a force when...
The work-energy theorem equates work done by all the forces on an object to the change in its kinetic energy. The theorem can be used to calculate work done by a force when...
Energy Diagrams - I
The dynamics of a mechanical system can be easily understood by interpreting a potential energy diagram. Since energy is a scalar quantity, the interpretation of the dynamics of the system becomes even simpler.
Take the example of a skater on a parabolic ramp. The potential energy at different points along the ramp will be proportional to the height of the ramp, which varies quadratically with the horizontal position on the ramp. As the skater moves down the ramp from the highest position,...
Take the example of a skater on a parabolic ramp. The potential energy at different points along the ramp will be proportional to the height of the ramp, which varies quadratically with the horizontal position on the ramp. As the skater moves down the ramp from the highest position,...
Energy Diagrams - II
Energy diagrams are important to understand the dynamics of a system. The topology of an energy diagram helps illustrate the equilibrium points of the system.
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The slope...
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The slope...
Potential-Energy Criterion for Equilibrium
Potential energy or potential function plays an essential role in determining the stability of a mechanical system. If a system is subjected to both gravitational and elastic forces, the potential function of the system can be expressed as the algebraic sum of gravitational and elastic potential energy. If the system is in equilibrium and is displaced by a small amount, then the work done on the system equals the negative of the change in the system's potential energy from the initial to the...

