100 research outputs found
Fine mapping and multidimensional analysis of carbon emission reduction in China
With the escalating impacts of global climate change, carbon peaking and carbon neutrality have become pressing issues of mutual concern for nations worldwide. Accurately measuring carbon emissions at regional and municipal levels in order to design differentiated reduction policies and promote carbon neutrality has become a challenging problem. To tackle this challenge, we developed a 250 m resolution grid map of carbon footprint data and constructed a national-level database (comprised of 2,800 county-level units) to analyze China’s carbon footprint from multiple angles such as overall characteristics, urban agglomerations, county-level units, population density, per capita disposable income, and more. This research provides fresh insights for studying multi-scale footprint spatial pattern dynamics. Our findings indicate that (1) The 250 m resolution Carbon Footprint Database developed in this study covers the national, provincial, county, urban, and rural areas, enabling dynamic research on multi-scale footprint spatial patterns; (2) The top 5% of areas with the highest carbon footprints account for approximately 1/5 of total carbon footprints in China, and approximately 1/4 of areas account for more than 50% of total carbon footprints; (3) The potential for reducing carbon emissions in China’s rural areas has been underestimated by over 10%, while those in the western regions are growing rapidly due to poverty alleviation efforts; (4) An inverted U-shaped “environmental Kuznets curve” emerges between disposable income and emissions intensity, with different regions exhibiting different consumption patterns. This study offers a novel approach for formulating reduction policies at different levels throughout the country
Research on Site Coverage Distribution of Beijing Based on Geographic Information System
Site coverage is an important index to learn spatial development pattern of the city. In this paper, with the help of spatial analysis functions of GIS, buffer and sector analysis are imposed in pursuit of finding possible spatial distribution rules of Beijing taken flagpole in Tian’anmen square as center. The results of sector analysis indicate that the building densities in such superior geographical condition areas as southeast and south are higher. Building densities of northern and western areas are low because of their bad terrain. The results of buffer analysis indicate the density of city center is the highest and have a negative relation with the augment of distance. That is to say, the average building density of center areas (buffer 1, 2 and 3, about 7.5km away) is about 26%. The average building density of transition region of city and countryside (buffer 10~20, about 25~50km away from center) is about 9%. The average building density of exurbs (after buffer 20~50km away from center) can't reach to 3%
Growth of carbon nanowalls at atmospheric pressure for one-step gas sensor fabrication
Carbon nanowalls (CNWs), two-dimensional "graphitic" platelets that are typically oriented vertically on a substrate, can exhibit similar properties as graphene. Growth of CNWs reported to date was exclusively carried out at a low pressure. Here, we report on the synthesis of CNWs at atmosphere pressure using "direct current plasma-enhanced chemical vapor deposition" by taking advantage of the high electric field generated in a pin-plate dc glow discharge. CNWs were grown on silicon, stainless steel, and copper substrates without deliberate introduction of catalysts. The as-grown CNW material was mainly mono- and few-layer graphene having patches of O-containing functional groups. However, Raman and X-ray photoelectron spectroscopies confirmed that most of the oxygen groups could be removed by thermal annealing. A gas-sensing device based on such CNWs was fabricated on metal electrodes through direct growth. The sensor responded to relatively low concentrations of NO2 (g) and NH3 (g), thus suggesting high-quality CNWs that are useful for room temperature gas sensors
Lightweight bamboo structures - Report on 2021 International Collaboration on Bamboo Construction
2021 International Collaboration on Bamboo Construction was held from September 1 to December 1, 2021. The practice was held by the College of Civil Engineering of Nanjing Forestry University, University College London, International Bamboo and Rattan Organisation (INBAR) and co-organized by 6 international institutions and national companies of China. Two main bamboo structures were setup by the teachers and students in the campus of Nanjing Forestry University. More than 50 students attended the practice, including international students from different countries. The practice was held to deliver the feasibility and applicability of bamboo in various geometries and different spans, and different areas. Innovative technologies like BIM Revit Architecture and Sketchup were used for the design of bamboo structures. The main principle of the practice was that the raising of bamboo structures should be simple using a minimum of materials aside from bamboo. The results of the project contributed to the popularization of the use of bamboo in the architecture, engineering and construction sectors
Does Abnormal Preoperative Coagulation Status Lead to More Perioperative Blood Loss in Spinal Deformity Correction Surgery?
This study aims to analyze the potential association between the preoperative coagulation status and perioperative blood loss in spinal deformity correction surgery. The preoperative coagulation status and estimated blood loss (EBL) during operation, postoperative wound drainage, and allogeneic transfusion during and after operation were recorded and analyzed. Among the 164 patients, 26 had a longer prothrombin time (PT), 13 had a lower fibrinogen level, 55 had a longer activated partial thromboplastin time (APTT), and 2 had a longer thrombin time (TT), and the platelet count (PLT) was all normal or higher than the normal level. The mean EBL per surgical level was 77.8 ml (range, 22–267 ml), and the mean drainage per surgical level was 52.7 ml (range, 7–168 ml). Fifty-five patients and 12 patients underwent allogeneic transfusion during and after the operation, respectively. The differences in EBL per surgical level, mean drainage per surgical level, the occurrences of allogeneic transfusion during and after operation between the patients with a longer PT, lower fibrinogen level, longer APTT or longer TT, and the normal controls were not significant (all P’s > 0.05). The Spearman correlation analysis showed that there was no correlation between PT, fibrinogen, APTT, TT or PLT with EBL per surgical level, mean drainage per surgical level, or allogeneic transfusion during and after the operation (all P’s > 0.05). The abnormal preoperative coagulation status but not hemophilia does not lead to more perioperative blood loss or a higher rate of perioperative allogeneic transfusion in spinal deformity correction surgery
Scaling of Berry-curvature monopole dominated large linear positive magnetoresistance
The linear positive magnetoresistance (LPMR) is a widely observed phenomenon
in topological materials, which is promising for potential applications on
topological spintronics. However, its mechanism remains ambiguous yet and the
effect is thus uncontrollable. Here, we report a quantitative scaling model
that correlates the LPMR with the Berry curvature, based on a ferromagnetic
Weyl semimetal CoS2 that bears the largest LPMR of over 500% at 2 Kelvin and 9
Tesla, among known magnetic topological semimetals. In this system, masses of
Weyl nodes existing near the Fermi level, revealed by theoretical calculations,
serve as Berry-curvature monopoles and low-effective-mass carriers. Based on
the Weyl picture, we propose a relation , with B being the applied magnetic field and the average Berry curvature near the Fermi surface, and further
introduce temperature factor to both MR/B slope (MR per unit field) and
anomalous Hall conductivity, which establishes the connection between the model
and experimental measurements. A clear picture of the linearly slowing down of
carriers, i.e., the LPMR effect, is demonstrated under the cooperation of the
k-space Berry curvature and real-space magnetic field. Our study not only
provides an experimental evidence of Berry curvature induced LPMR for the first
time, but also promotes the common understanding and functional designing of
the large Berry-curvature MR in topological Dirac/Weyl systems for magnetic
sensing or information storage
The N-terminus of FILIA Forms an Atypical KH Domain with a Unique Extension Involved in Interaction with RNA
FILIA is a member of the recently identified oocyte/embryo expressed gene family in eutherian mammals, which is characterized by containing an N-terminal atypical KH domain. Here we report the structure of the N-terminal fragment of FILIA (FILIA-N), which represents the first reported three-dimensional structure of a KH domain in the oocyte/embryo expressed gene family of proteins. The structure of FILIA-N revealed a unique N-terminal extension beyond the canonical KH region, which plays important roles in interaction with RNA. By co-incubation with the lysates of mice ovaries, FILIA and FILIA-N could sequester specific RNA components, supporting the critical roles of FILIA in regulation of RNA transcripts during mouse oogenesis and early embryogenesis
Performance Evaluation of Industrial Land Policy in China
Rapid industrialization, as one of the main driving forces promoting sustainable economic growth, has increased the area of industrial land use significantly. Industrial land use manifests that the competition between it and other kinds of land use is growing. During the last decade in China, many targeted industrial land use policies have been enacted to stimulate appropriate industrial land use and to promote healthy economic development. However, it is difficult for scholars and governments of rapidly developing countries to judge and evaluate the performance of such policies. Based on statistical data gathered over almost 10 years and an idea called “industrial land equivalent” (ILE), this paper analyzes the contribution made by the implementation of industrial land use policy to economic development, using a Cobb-Douglas production function by which to quantify the influence of land institutions and land regulation systems. The result of the study shows that factors, such as industrial land, labor and capital, all play an important role in GDP growth. Additionally, it is found that industrial land institutions and regulation systems have a strongly positive influence on economic development. It was also found that the influence of policy in eastern China is greater than that in the west and that repeated, short-term land regulation has a negative effect on the economy. Therefore, it is profoundly important for the Chinese economy that a stable and durable industrial land use policy be maintained as the industrial center migrates to the Midwest. The research philosophy and method offered by this paper have great significance for the quantitative evaluation of policy performance
Analysis of Land-Use Emergy Indicators Based on Urban Metabolism: A Case Study for Beijing
The correlation of urban metabolism and changes in land use is an important issue in urban ecology, but recent research lacks consideration of the mechanisms and interactions between them. In this research, we did an emergy analysis of the flows of materials, energy, and capital within the socioeconomic system of Beijing. We calculated emergy-based evaluation indices of urban metabolism and land use change, to analyze the relationship between urban metabolism and land use by correlation analysis and regression analysis. Results indicate that the socio-economic activities on built-up land depend on local, non-renewable resource exploitation and external resource inputs. The emergy utilization efficiency of farmland has consistently decreased, but there remains significant utilization potential there. Urban development in Beijing relies on production activities on built-up land, which is subjected to great environmental pressure during extraction of material resources. To keep the economy developing effectively, we suggest that Beijing should commit to development of a circular economy, and change the land-use concept to “Smart Growth”. In this paper, we efficaciously solve the problem of conflicting measurement units, and avoid the disadvantages of subjective assignment. Consequently, this work provides not only a more scientific way to study land problems, but also provides a reliable reference for ecological construction and economic development in Beijing
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