A Longitudinal Spatial-Temporal Analysis of Ancient Village Tourism Development in Zhejiang, China

The sustainable development of tourism is essential for revitalizing historically and culturally significant ancient villages in China. Despite the longstanding recognition of the relationship between the spatial distribution of village destinations and their sustainable development, there is a dearth of longitudinal studies in village tourism. Using the geographic information system (GIS) spatial analysis method and the exploratory spatial data analysis model, this study explored the spatial-temporal features of ancient village tourism over three important time nodes of rural tourism development (in Zhejiang, China), as well as the contributing factors at both the provincial and prefectural city levels. The findings of this study suggested a spatial inequality in the distribution of ancient villages, in terms of tourism development over time. In particular, tourism development was clustered in the southern region, with a noticeable spillover effect. Meanwhile, transportation, source markets, and physical topography are essential factors contributing to this spatial distribution. The study contributes to ancient village tourism development literature and offers meaningful, practical implications for regional governments and business investors

Experimental study on directional drilling with high pressure nitrogen in soft-fragmentized coal seam of Wangpo Coal Mine

Aiming at the characteristics of poor cementation and broken seam in Wangpo Coal Mine, the pneumatic directional drilling test of soft-fragmentized coal seam with high-pressure nitrogen slag discharge was carried out. Drilling equipment selection, pneumatic directional technology, deep hole and high wind pressure drilling parameters are studied. In the 3306 working face test of Wangpo Coal Mine, four directional drilling holes of broken soft coal seam were completed, in which the pneumatic directional branch was successfully tested for two times. The average daily footage reached 82.3 m, the maximum single shift footage was 72 m, and the maximum hole depth was 437 m, creating the record of hole depth for soft gas dynamic directional construction. The test results show that the pneumatic directional drilling technology meets the requirements of directional construction along the broken soft coal seam in Wangpo Mine, and the drilling trajectory is accurate and controllable. The coal seam drilling rate is high, the drilling depth is large, the drilling performance is good, and the drilling efficiency is high

Sensorineural hearing loss and cognitive impairment: three hypotheses

Sensorineural hearing loss (SNHL) is a category of hearing loss that often leads to difficulty in understanding speech and other sounds. Auditory system dysfunction, including deafness and auditory trauma, results in cognitive deficits via neuroplasticity. Cognitive impairment (CI) refers to an abnormality in the brain’s higher intellectual processes related to learning, memory, thinking and judgment that can lead to severe learning and memory deficits. Studies have established a strong correlation between SNHL and CI, but it remains unclear how SNHL contributes to CI. The purpose of this article is to describe three hypotheses regarding this relationship, the mainstream cognitive load hypothesis, the co-morbidity hypothesis, and the sensory deprivation hypothesis, as well as the latest research progress related to each hypothesis

Metal modified hexaaluminates for syngas generation and CO2 utilization via chemical looping

Chemical looping CH4-CO2 reforming (CLDR) is an emerging technology for the generation of Fischer-Tropsch ready syngas and CO2 utilization, which is strongly dependent upon the improvement in the design of efficient oxygen carriers (OCs). In this present work, different metal additives (Si, Zr and Ce ions) were introduced into Fe-based hexaaluminates and used OCs for CLDR. The microstructure and reactivity of BaFe2.8M0.2Al9O19 (M = Fe, Si, Zr, and Ce) OCs were found greatly influenced by the metal additives and CH4/CO2 redox treatment. Pure Fe and Ce doped OCs showed the co-existence of both beta-Al2O3 and MP hexaaluminate phases, while the introduction of Si and Zr in the hexaaluminate structure led to the phase transformation from beta-Al2O3 into MP. During the CH4/CO2 redox process, large amounts of Fe species in both BaFe2.8Si0.2Al9O19 and BaFe2.8Zr0.2Al9O19 OCs were gradually stabilized in sintering FeAl2O4 with low oxygen-storage capacity, which resulted in low CH4 reactivity and weak cyclic stability. However, Ce-doped BaFe2.8Ce0.2Al9O19 OC showed good reactivity and stability during the 10 redox cycles with CH4 conversion of 93%, H-2/CO ratio of similar to 2, high syngas yield of 2.2 mmol/g, and high CO2 activation ability of 0.95 mmol/g, which was associated with the preservation of hexaaluminate main phase, the formation of CeFexAl1-xO3 and the abundant oxygen vacancies. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

A Network Flow Analysis of the Nitrogen Metabolism in Beijing, China

Rapid urbanization results in high nitrogen flows and subsequent environmental consequences. In this study, we identified the main metabolic components (nitrogen inputs, flows, and outputs) and used ecological network analysis to track the direct and integral (direct + indirect) metabolic flows of nitrogen in Beijing, China, from 1996 to 2012 and to quantify the structure of Beijing’s nitrogen metabolic processes. We found that Beijing’s input of new reactive nitrogen (<i>Q</i>, which represents nitrogen obtained from the atmosphere or nitrogen-containing materials used in production and consumption to support human activities) increased from 431 Gg in 1996 to 507 Gg in 2012. Flows to the industry, atmosphere, and household, and components of the system were clearly largest, with total integrated inputs plus outputs from these nodes accounting for 31, 29, and 15%, respectively, of the total integral flows for all paths. The flows through the sewage treatment and transportation components showed marked growth, with total integrated inputs plus outputs increasing to 3.7 and 5.2 times their 1996 values, respectively. Our results can help policymakers to locate the key nodes and pathways in an urban nitrogen metabolic system so they can monitor and manage these components of the system

Microstructure and electrical contact behavior of the nano-yttria-modified Cu-Al2O3/30Mo/3SiC composite

With the rapid development of the copper-based composite in the field of electrical contact material industry, the problem of poor arc erosion resistance of the copper-based material becomes more and more prominent. Improving the arc erosion resistance of the copper-based composite is an urgent problem to be solved. Cu-Al2O3/30Mo/3SiC and 0.5Y2O3/Cu-Al2O3/30Mo/3SiC electrical contact composites were prepared in a fast-hot-pressing sintering furnace. The microstructure and phase structure of the composites were analyzed by using a scanning electron microscope, transmission electron microscope, and X-ray diffraction meter, respectively. The arc erosion properties of the composites at 25 V, DC and 10-30 A were investigated by using a JF04C electric contact tester. The mass loss of the composites was reduced by 77.8%, and the arc erosion rate was reduced by 79.6% after the addition of nano-yttrium oxide under the experimental conditions of 25 V, DC and 30 A. At the same time, the arc energy and welding force of the composite after switching operations decreased, indicating that the addition of nano-yttria improved the arc erosion resistance of the composite. This work provides a new method for improving the arc erosion resistance of the copper-based composite contact material