Microstructure and Mechanical Properties of Magnetron Sputtering TiN-Ni Nanocrystalline Composite Films

In this paper, TiN-Ni nanostructured composite films with different Ni contents are prepared using the magnetron sputtering method. The composition, microstructure, and mechanical properties of composite films are analyzed using an X-ray energy spectrometer (EDS), a scanning electron microscope (SEM), X-ray diffraction technology (XRD), a transmission electron microscope (TEM), and nanoindentation. All the films grow in a columnar crystal structure. There are only TiN diffraction peaks in the XRD spectrum, and no diffraction peaks of Ni and its compounds are observed. The addition of the Ni element disrupts the integrity of TiN lattice growth, resulting in a decrease in the grain size from 60 nm in TiN to 25 nm at 20.6% Ni. The film with a Ni content of 12.4 at.% forms a nanocomposite structure in which the nanocrystalline TiN phase (nc-TiN) is surrounded by the amorphous Ni (a-Ni) phase. The formation of nc-TiN/a-Ni nanocomposite structures relies on the good wettability of Ni on TiN ceramics. The hardness and elastic modulus of the film gradually decrease with the increase in Ni content, but the toughness is improved. The hardness and elastic modulus decrease from 19.9 GPa and 239.5 GPa for TiN film to 15.4 GPa and 223 GPa at 20.6 at.% Ni film, respectively, while the fracture toughness increases from 1.5 MPa m1/2 to 2.0 MPa m1/2. The soft and ductile Ni phase enriched at the TiN grain boundaries hinders the propagation of cracks in the TiN phase, resulting in a significant increase in the film’s toughness. The research results of this paper provide support for the design of TiN-Ni films with high strength and toughness and the understanding of the formation mechanism of nanocomposite structures.info:eu-repo/semantics/publishedVersio

Analysis of m6A methylation expression profiles in liver tissue of high-fat diet-induced mouse models of NAFLD

Objective·To detect the differences in m6A methylation modification and gene expression of liver tissue mRNA in high-fat diet-induced mouse models of non-alcoholic fatty liver disease (NAFLD) using microarray technology.Methods·The NAFLD models were established in 6-8 weeks old male C57BL/6J mice fed with high-fat chow for 16 weeks (high-fat group, n=10). The basal group (n=10) was given 10% fat diet. Hematoxylin-eosin (H-E) staining was used to assess the histopathological changes in liver tissue and to determine the success of the NAFLD models. The changes of mRNA m6A methylation and expression levels in the liver tissues of the two groups were detected by using methylated RNA immunoprecipitation (MeRIP) and microarray expression profiling.Results·The livers of the mice in the basal group were bright red with few fat deposits, while the livers of the mice in the high-fat group were yellowish with diffuse infiltration and fusion of lipid droplets in the hepatocytes by H-E staining, suggesting that the high-fat diet-induced NAFLD models were successfully constructed. The results of the MeRIP-microarray showed that the m6A methylation levels of 320 genes in the livers of mice in the high-fat group were significantly altered compared with those in the basal group (P1.5), of which 108 genes were up-regulated and 212 genes were down-regulated. Genes with significant differences in m6A methylation levels between the two groups were intersected with those with differentially expressed mRNAs, and 163 genes were found to have significant differences in both m6A methylation level and mRNA expression level.Conclusion·The change in m6A modification of liver tissue mRNA in the high-fat diet-induced mouse models of NAFLD is significant and the change is associated with the gene expression of mRNA

Designing forest biodiversity experiments : general considerations illustrated by a new large experiment in subtropical China

Funded by German Research Foundation. Grant Number: DFG FOR 891/1 and 2 National Natural Science Foundation of China. Grant Numbers: NSFC 30710103907, 30930005, 31170457 , 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in BeijingPeer reviewedPublisher PD

Designing forest biodiversity experiments: general considerations illustrated by a new large experiment in subtropical China


 Biodiversity-ecosystem functioning (BEF) experiments address ecosystem-level consequences of species loss by comparing communities of high species richness with communities from which species have been gradually eliminated. BEF experiments originally started with microcosms in the laboratory and with grassland ecosystems. A new frontier in experimental BEF research is manipulating tree diversity in forest ecosystems, compelling researchers to think big and comprehensively.
 We present and discuss some of the major issues to be considered in the design of BEF experiments with trees and illustrate these with a new forest biodiversity experiment established in subtropical China (Xingangshan, Jiangxi Province) in 2009/2010. Using a pool of 40 tree species, extinction scenarios were simulated with tree richness levels of 1, 2, 4, 8 and 16 species on a total of 566 plots of 25.8 × 25.8 m each.
 The goal of this experiment is to estimate effects of tree and shrub species richness on carbon storage and soil erosion; therefore, the experiment was established on sloped terrain. The following important design choices were made: (i) establishing many small rather than fewer larger plots, (ii) using high planting density and random mixing of species rather than lower planting density and patchwise mixing of species, (iii) establishing a map of the initial 'ecoscape' to characterize site heterogeneity before the onset of biodiversity effects and (iv) manipulating tree species richness not only in random but also in trait-oriented extinction scenarios.
 Data management and analysis are particularly challenging in BEF experiments with their hierarchical designs nesting individuals within-species populations within plots within-species compositions. Statistical analysis best proceeds by partitioning these random terms into fixed-term contrasts, for example, species composition into contrasts for species richness and the presence of particular functional groups, which can then be tested against the remaining random variation among compositions.
 We conclude that forest BEF experiments provide exciting and timely research options. They especially require careful thinking to allow multiple disciplines to measure and analyse data jointly and effectively. Achieving specific research goals and synergy with previous experiments involves trade-offs between different designs and requires manifold design decisions.&#13

Analysis of the Urban Land Use Efficiency in the New-Type Urbanization Process of China’s Yangtze River Economic Belt

The accelerated urbanization process in China has caused a shift in the urban land use structure. The Chinese government has issued ‘the National New-type Urbanization Plan’ focusing on the rational use of resources, which is of great significance for the intensification and sustainability of land use. In promoting the construction of the new-type urbanization (N-TU), enhancing the urban land use efficiency (ULUE) is crucial to regional coordinated development. This study uses panel data from 2011 to 2020 for 11 provinces (cities) in the Yangtze River Economic Belt (YREB) and adopts the super efficiency (SE) slacks-based measure (SBM) model with undesirable outputs and the entropy weight method to calculate the ULUE and N-TU levels. The study uses the System generalized method of moment (Sys-GMM) to study the N-TU’s impact on the ULUE empirically. The results indicate: (i) the overall trend of new-type urbanization level is gradually increasing and has the characteristics of uneven spatial distribution between provinces. (ii) The ULUE shows a fluctuating upward trend during the studied period. (iii) The N-TU and its subsystems have significant positive effects on the ULUE. Overall, this study aims to explore the relationship between the N-TU and ULUE enriching the theoretical analysis and empirical research in related fields, thus helping decision makers in the assessment and design of policy recommendations

Effect of Urban-Rural Income Gap on the Population Peri-Urbanization Rate in China

Attracted by the urban–rural income gap (URIG), a massive agricultural transfer population has flooded into cities and became a peri-urbanized population due to the restrictions of the household registration system. This trend eventually leads to the rising population peri-urbanization rate (PPUR), which is equal to the proportion of urban resident population with rural household registration in the total residents, and seriously affects the development of new-type people-oriented urbanization. The purpose of this study is to investigate the impact of URIG on PPUR at the national and regional levels using the spatial exploration analysis and spatial Durbin model from the perspective of comparative economic interests. Empirical results revealed that PPUR had high spatial agglomeration, as indicated by high values in Eastern China and low values in Central and Western China. Moreover, the PPUR of most provinces in China was rising, dominated by intermediate values. At the national level, URIG promoted the increase of PPUR in the province, but inhibited the increase of PPUR in nearby provinces. Except for household registration, other control variables, such as industrial structure, fixed asset formation rate, infrastructure, medical resources and land-centered urbanization, also contributed to the PPUR in the province. At the regional level, the URIG of Central and Western China contributed to the increase of PPUR, whereas in Eastern China it inhibited the increase of PPUR. The strong correlation of URIG and PPUR calls for relevant policies for narrowing URIG and reducing PPUR

Molecular dynamics study on the kinematic viscosity, density and structure of fuel blends containing n-decane and biofuel compound of ethyl decanoate or ethyl dodecanoate

Bio-aviation fuel is blend consisting of aviation kerosene and biofuels, which is a clean renewable energy and has gained considerable attention in recent years. However, numerical studies on the thermophysical properties of bio-aviation fuel containing fatty acid esters are still limited. In this paper, the kinematic viscosity and density of fuel blends containing n-decane and biofuel compound of ethyl decanoate or ethyl dodecanoate are investigated by molecular dynamics (MD) method, and the calculated viscosities are compared with those by a theoretical model of UNIFAC-VISCO (UV). The MD results applying with a PCFF force field (FF) can reproduce the experimental data for the fuel blends very well in comparison with both the COMPASS FF and the UV model. In addition, to link the variety of molecular structure to the changes of their thermophysical properties, local structures of n-decane and ethyl decanoate in mixture are systematically analyzed. It illustrates that a decreasing end-to-end length of molecular chains combined with the growing intermolecular distance leads to the reduction of the kinematic viscosity of fuel blends with the increasing of temperature. This work provides a baseline to help understand the thermophysical properties of esters and their based bio-aviation kerosene surrogates

Effect of Urban-Rural Income Gap on the Population Peri-Urbanization Rate in China

Attracted by the urban–rural income gap (URIG), a massive agricultural transfer population has flooded into cities and became a peri-urbanized population due to the restrictions of the household registration system. This trend eventually leads to the rising population peri-urbanization rate (PPUR), which is equal to the proportion of urban resident population with rural household registration in the total residents, and seriously affects the development of new-type people-oriented urbanization. The purpose of this study is to investigate the impact of URIG on PPUR at the national and regional levels using the spatial exploration analysis and spatial Durbin model from the perspective of comparative economic interests. Empirical results revealed that PPUR had high spatial agglomeration, as indicated by high values in Eastern China and low values in Central and Western China. Moreover, the PPUR of most provinces in China was rising, dominated by intermediate values. At the national level, URIG promoted the increase of PPUR in the province, but inhibited the increase of PPUR in nearby provinces. Except for household registration, other control variables, such as industrial structure, fixed asset formation rate, infrastructure, medical resources and land-centered urbanization, also contributed to the PPUR in the province. At the regional level, the URIG of Central and Western China contributed to the increase of PPUR, whereas in Eastern China it inhibited the increase of PPUR. The strong correlation of URIG and PPUR calls for relevant policies for narrowing URIG and reducing PPUR

An optimum method for latticed shells based on concept of the compression line

To improve the load-carrying capacity latticed shells, an innovative optimum method based on the concept of compression line is proposed in this paper. The basic principle of this method is using the character without moment in compression line. The arc line which forms the contour line of sphere and latticed shell structures is substituted by compression line in this method. Then the latticed shell structures are in the state of compression, and the influence of bending stress reduces greatly. As a result, the load-carrying capacity of the latticed shell structure is increased. Through the geometrical nonlinear analysis of a sunflower-patterned single-layer latticed shell structure with a span of 48m, it is found that the load-carrying capacity of the single-layer latticed shell structure can be improved by 5.48%. Furthermore, the results of 84 structural analyses of single-layer or double-layer sphere and cylinder latticed shell structures show that the optimum method is right and effective. And especially, it is applicable to single-layer latticed shell structure with rise-span ratio 1/5 with the max improvement 6.4% of load-carrying capacity