Research on Ecological Corridor Planning of Lanzhou Yuzhong Ecological Innovation City from the Perspective of Ecological Civilization

The practice and research of ecological civilization is a focus of current planning and design, as well as a scientific strategy under the current situation of resource constraint, environmental degradation and ecosystem degradation. Urban elements such as buildings, green land, farmland,water systems and mountains can be connected by ecological corridors into a green ecological system design.At present, many ecological and environmental problems, such as urban heat island effect, fog and haze, automobile exhaust have a negative effect on the construction of social ecological environment. In order to build a new modern city with prosperous economy, beautiful environment and social civilization, scientific and efficient ecological corridors should be designed to improve the environmental quality of the eco-city, and promote the construction and development of ecological civilization and green cities. Based on the relevant research and specific practices of ecological corridors at home and abroad,combine the needs of the planning and construction of the Yuzhong Ecological Innovation City, and discuss on the connotation and characteristics of ecological corridors, and discuss the key elements of ecological corridor planning.This article will take the ecological corridor planning of Yuzhong Eco Innovation City as an example. We design ecological corridor based on field investigation, literature and geographic information system..The planning and design of the ecological corridor in the planning area proposed in this paper can provide positive suggestion on the planning and design of the ecological corridor in other ecological innovation cities

Lotus rhizome-like S/N-C with embedded WS2 for superior sodium storage

Sodium-ion batteries (SIBs) hold great promise as power sources because of their low cost and decent electrochemical behavior. Nevertheless, the poor rate performance and long-term cycling capability of anode materials in SIBs still impede their practical application in smart grids and electric vehicles. Herein, we design a delicate method to embed WS2 nanosheets into lotus rhizome-like heteroatom-doped carbon nanofibers with abundant hierarchical tubes inside, forming WS2@sulfur and nitrogen-doped carbon nanofibers (WS2@S/N-C). The WS2@S/N-C nanofibers exhibit a large discharge capacity of 381 mA h g-1 at 100 mA g-1, excellent rate capacity of 108 mA h g-1 at 30 A g-1, and a superior capacity of 175 mA h g-1 at 5 A g-1 after 1000 cycles. The excellent performance of WS2@S/N-C is ascribed to the synergistic effects of WS2 nanosheets, contributing to larger interlayer spacing, and the stable lotus rhizome-like S/N-C nanofiber frameworks which alleviate the mechanical stress. Moreover, the WS2@S/N-C electrode shows obvious pseudocapacitive properties at 1 mV s-1 with a capacitive contribution of 86.5%. In addition, density functional theory calculations further indicate that the WS2@S/N-C electrode is very favorable for Na storage. This novel synthetic strategy is a promising method for synthesizing other electrode materials for rechargeable batteries in the future

A S/N-doped high-capacity mesoporous carbon anode for Na-ion batteries

Low-cost Na-ion batteries (SIBs) are a promising alternative to Li-ion batteries (LIBs) for large-scale energy storage systems due to the abundant sodium resources and eco-friendliness. The volumetric changes of sodium anodes during the sodiation/desodiation processes, however, reduce the cycling life of Na-ion batteries. In order to solve the problem, we have used the electrospinning method to successfully fabricate mesoporous S/N-doped carbon nanofibers (S/N-C), which show a high capacity and high-rate capability in a Na-ion battery. The S/N-C nanofibers delivered a high reversible capacity of 552.5 and 355.3 mA h g -1 at 0.1 and 5 A g -1 , respectively, because of the high S-doping (27.95%) in the carbon nanofibers. The introduction of N and S in S/N-C nanofibers increases the active sites for Na + storage and reduces the energy required for Na + transfer, as confirmed by in situ Raman spectroscopy and density functional theory (DFT) calculations. Moreover, the mesoporous S/N nanofibers are wetted by liquid electrolyte, which facilitates the Na + transport and increases the rate performance, thus making them a suitable anode material for SIBs and other electrochemical energy storage devices