相关实验视频
Updated: May 13, 2025
10:09
Operation of the Collaborative Composite Manufacturing CCM System
Published on: October 1, 2019
6.5K
分析航空物流与区域经济之间的合协调:确定合机制和关键影响因素
Lijun Liang1, Peirong Chen2, Mengwan Zhang3
1School of Business, Beijing Information Science and Technology University (BISTU), Beijing, China.
PloS one
|May 9, 2025
概括
航空物流和区域经济 (AL&RE) 协调对发展至关重要. 这项研究显示,民用航空发展基金和环境投资是关键驱动因素,货运额显著影响合增长.
科学领域:
- 经济学 经济学 经济学
- 运输研究 运输研究
- 区域科学 地区科学
背景情况:
- 航空物流与区域经济 (AL&RE) 之间的关系是相互加强的.
- 了解和增强这种协同作用对于可持续的区域发展至关重要.
- 现有的研究往往忽视了对AL&RE合协调和影响因素的综合分析.
研究的目的:
- 开发一个研究框架来评估AL&RE之间的合协调水平.
- 确定区域AL&RE的关键影响因素.
- 为协调经济发展指导区域政策的制定.
主要方法:
- 合协调度模型与灰色关系分析的整合.
- 使用来自中国四川省 (2013-2023) 的数据进行实证分析.
- 分析关键指标,包括GDP,环境污染控制投资和民用航空指标.
主要成果:
- 地方政府对民航发展基金和环境投资的支出对区域经济和AL&RE产生重大影响.
- 在AL&RE之间的合程度仍然很高,协调总体上有所改善,尽管容易受到内部失衡的影响.
- 民用航空货运周转,吞吐量和起飞/降落任务是影响合协调的最重要的指标.
结论:
- 影响AL&RE发展的关键因素与影响其合协调的关键因素不同,突出显示了系统的非线性.
- 该研究为AL&RE复合系统及其合机制提供了理论框架.
- 提出了加强AL&RE协调,整合可持续区域经济发展的绿色指标的建议.
相关概念视频
01:12Regional Terms
9.1K
Regional terms describe anatomy by dividing the body parts into different regions that contain structures involved in contributing similar functions. Using these terms helps increase the accurate description and identification of the particular region of interest or region affected by the disease.
Primarily, the human body has two major regions, the axial and appendicular regions. The axial region comprises regions from the head to the abdomen and makes up the central body axis. In contrast,...
Primarily, the human body has two major regions, the axial and appendicular regions. The axial region comprises regions from the head to the abdomen and makes up the central body axis. In contrast,...
9.1K
01:27¹H NMR: Long-Range Coupling
1.6K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.6K
02:12Short-distance Transport of Resources
15.6K
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
15.6K
01:23Insulation Coordination
99
Insulation coordination is the process of matching electric equipment's insulation strength with protective device characteristics to protect the equipment against expected overvoltages. This selection is based on engineering judgment and cost. Equipment can generally withstand short-duration high transient overvoltages, but repeated tests with identical waveforms can yield inconsistent results. As a result, standard impulse voltage waveforms are used for testing, defined by specific times...
99
02:57Coordination Number and Geometry
15.3K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
15.3K
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
999
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
999