Search

A low-temperature operated in situ synthesis of TiC-modified CNTs is demonstrated to improve the thermal stability and electrochemical properties of CNTs.

The changes and interrelationships of ecosystem services at different global and regional scales have been actively investigated. Clarifying the trade-offs and synergies between ecosystem services from a multi-scale scientific perspective is vital to improve the coordinated and sustainable development of the watershed and ecological protection. As an important ecological barrier region of the Yellow River Basin, the Henan section provides a variety of important ecosystem services. This study analyzes the characteristics of land use changes in the Yellow River Basin (Henan section) from 1990 to 2020. Based on the InVEST model, four ecosystem services—water production, soil conservation, carbon storage and food supply have been evaluated. The Spearman correlation coefficient was used to further reveal the spatial and temporal characteristics of the trade-offs and synergies at different levels of each service. The results showed that: (1) From 1990 to 2020, the basin was dominated by farmland conservation. The construction land area mainly exhibited an inflow behavior, while other land use types were mainly related to outflow. (2) From 1990 to 2020, the water yield, soil conservation and carbon storage first increased and then decreased, while food supply gradually increased. The spatial distribution of these ecosystem services was lower in the southwest and slightly higher in the northeast and farmland had the highest capacity of water production and food supply, while woodland had the highest capacity for soil conservation and carbon storage. (3) The Spearman rank correlation coefficient indicated that the trade-offs for the ecosystem services in the Yellow River Basin (Henan section) dominated before 2000, and the synergies gradually strengthened after 2000. (4) There were clear spatial heterogeneities in the ecosystem services of the basin; for instance, the functions in the middle and lower reaches of the Yellow River Basin (Henan section) were mainly trade-offs, while the higher elevations in the middle reaches exhibited synergistic relationships. This study aims to clarify the trade-offs and synergies between ecosystem services at the different levels. Based on our findings, countermeasures and suggestions for ecological protection and management are proposed to promote the coordinated development of social economy and ecological protection.

Throughout evolutionary history, animals are finely tuned to adjust their behaviors corresponding to environmental variations. Behavioral flexibility represents an important component of a species’ adaptive capacity in the face of rapid anthropogenetic environmental change, and knowledge of animal behaviours is increasingly recognized in conservation biology. In aquatic ecosystem, variation of water depth is a key factor affecting the availability of food, thus the foraging behaviours of many waterbirds, especially piscivores. In this study, we compared the foraging behaviours of Scaly-sided Merganser (Mergus squamatus), an endangered migratory diving duck endemic to east Asia, in habitats with different water depth, using video camera records obtained from the known wintering sites during three winters from 2018-2020. Further, the energy expenditure of foraging behavior profile and energy intake based on fish sizes were calculated to study the foraging energetics. In total, 200 effective video footages that contained 1,086 minutes with 17,995 behaviours and 163 events of catching fish were recorded. Results showed that 1) time length for fishing (including eye-submerging, head-dipping, diving and food handling) of Mergus squamatus in shallow waters was significantly more than in deep waters; 2) Mergus squamatus spent significantly more time for preparing (including vigilance, preening and swimming) in deep waters than in shallow waters; 3) the mean catch rate was 0.28 fish/minute in shallow waters, which is significantly higher than the value of 0.13 fish/minute in deep waters; 4) despite the distinct foraging behaviour profiles and energy intakes, Mergus squamatus showed similar energetics in shallow and deep waters. We concluded that Mergus squamatus is a good example of behavioural flexibility that aligns with expectations of optimum foraging theory, in that it behaves in accordance to resource availability in different environments, resulting in high foraging efficiency. The behavioural flexibility can be related to its evolution history.

Three-dimensional (3D) micro-supercapacitors (MSCs) with superior performances are desirable for miniaturized electronic devices. 3D interdigitated MSCs fabricated by bulk micromachining technologies have been demonstrated for silicon wafers. However, rational design and fabrication technologies of 3D architectures still need to be optimized within a limited footprint area to improve the electrochemical performances of MSCs. Herein, we report a 3D interdigitated MSC based on Si/C/CNT@TiC electrodes with high capacitive properties attributed to the excellent electronic/ionic conductivity of CNT@TiC core-shells with a high aspect ratio morphology. The symmetric MSC presents a maximum specific capacitance of 7.42 mF cm

Understanding the characteristics of urban green-space water consumption is crucial to sustainable urban development under urbanization and water scarcity. However, temporal–spatial and driving characteristics of urban green-space water consumption are still unknown. Characteristics and driving factors of urban green-space water consumption in 286 cities in China are analyzed in this study. Results showed that the urban green-space water consumption (m3/ha) of 286 cities changed (decreased: 250, increased: 36, and p 12,570 m3/ha) and 74 cities present low water consumption (≤6,380 m3/ha). High and low water consumption cities are aggregated in southern and northern China, respectively. Urban water supply, education, number of patents, GDP per capita, temperature, rainfall, and park areas significantly increased the urban green-space water consumption (p

The value of ecosystem services is an extremely important parameter that reflects regional ecological benefits and resources. Estimating the value of ecosystem services is essential for regional land-use optimization, ecological construction, and biodiversity protection. In this study, Landsat-TM/ETM remote sensing images were used to analyze land-use data in 1990, 2000, 2010, and 2020 of the Yellow River Basin (Henan section), China, defined by natural boundaries. An equivalent factor method was used to construct a model to calculate the ecosystem services value that introduced grain yield, regional difference coefficient, and social development stage coefficient. Thus, land-use changes and evolution of ecosystem services values in the Yellow River Basin (Henan section) in the past 30 years were analyzed. Land use in the basin changed significantly from 1990 to 2020. Except for an increase in area of construction land, areas of other land-use types decreased. Cultivated land area first increased and then decreased, whereas the water area first decreased and then increased. The total value of ecosystem services in the study area fluctuated but increased overall by 43.82 × 108 USD in the past 30 years. Spatially, the total value of ecosystem services was high in the southwest and low in the northeast. Among individual ecosystem service values, water conservation, gas regulation, and climate regulation accounted for a relatively high proportion of the total value. Regulation services were the main ecosystem service functions, followed by support and supply services, with cultural services accounting for the lowest proportion. Sensitivity coefficients of different land types in different periods were all less than one. Therefore, the value coefficients were reasonable, and the results were consistent with the actual situation of the study area. The study improves the method to estimate the ecosystem services value of the basin and also indicates ways to support ecological protection of the Yellow River Basin (Henan section), China.

The temporal and spatial evolution of landscape pattern is the most intuitive form of land use transition. Analyzing the change of landscape pattern and its driving factors is of great significance to land use management and water quality protection in the basin. Based on the land use data obtained from the remote sensing image interpretation of the Yellow River Basin (Henan section) in 1990, 2000, 2010, and 2020, the landscape pattern evolution characteristics of the Yellow River Basin (Henan section) were quantitatively studied using the methods of multi-angle land use transfer matrix, land use information atlas, and landscape pattern index, and the influencing factors of landscape pattern evolution of the Yellow River Basin (Henan section) were revealed using the geographic detectors (a new statistical method to measure the explanatory power of independent variables to dependent variables mainly by analyzing the overall differences among various types of geographical spaces). The results show that: (1) From 1990 to 2020, the mutual transformation of land use types in the Yellow River Basin (Henan section) was frequent, and the transformation tracks were diversified. Among them, the outflow behavior of land use types is mainly manifested in the transformation from cultivated land to construction land, and the inflow behavior of land use types is mainly manifested in the transformation from grassland and water to cultivated land. (2) In the information map of land use change in the Yellow River Basin (Henan section) from 1990 to 2020, the stable type had the widest distribution range, accounting for 94.60% of the total area of the study area, with two main change patterns: “cultivated land-cultivated land-cultivated land-cultivated land” and “woodland-woodland-woodland-woodland”, which indicates that the landscape pattern of the basin dominated by cultivated land and woodland has not changed fundamentally. The four land use change structure types, repeated change, early change, intermediate change and continuous change, account for a relatively small proportion and are concentrated in the vicinity of the Yellow River. (3) At the landscape level, the watershed generally shows the trend of decreasing landscape fragmentation, increasing landscape heterogeneity and constantly balancing landscape patch types. At the level of patch type, the landscape dominance of cultivated land decreases, while that of construction land increases. The occupation of construction land is the main reason for the fragmentation and homogenization of cultivated land. (4) From the perspective of landscape scale and patch type scale, through the geographical exploration of various natural factors and socio-economic factors that potentially affect the landscape pattern evolution, it is found that the spatial differences of natural factors such as slope, elevation, temperature, and precipitation can better reflect the spatial heterogeneity of the landscape pattern in the Yellow River Basin (Henan section) than those of socio-economic factors such as GDP and population density, and the interaction of any two driving factors has a greater influence on the spatial distribution characteristics of landscape pattern than any single factor, indicating that the formation of spatial heterogeneity in the Yellow River Basin (Henan section) is the result of the interaction of various influencing factors. The results of this study can provide ideas for exploring the trend and influencing mechanism of landscape pattern change in the basin, and have important reference significance for ecological environment management, ecosystem protection, and land use planning in the Yellow River Basin (Henan section).

The significant spatial heterogeneity among river basin ecosystems makes it difficult for local governments to carry out comprehensive governance for different river basins in a special administrative region spanning multi-river basins. However, there are few studies on the construction of a comprehensive governance mechanism for multi-river basins at the provincial level. To fill this gap, this paper took Henan Province of China, which straddles four river basins, as the study region. The chord diagram, overlay analysis, and carbon emission models were applied to the remote sensing data of land use to analyze the temporal and spatial patterns of carbon storage caused by land-use changes in Henan Province from 1990 to 2018 to reflect the heterogeneity of the contribution of the four basins to human activities and economic development. The results revealed that food security land in the four basins decreased, while production and living land increased. Ecological conservation land was increased over time in the Yangtze River Basin. In addition, the conversion from food security land to production and living land was the common characteristic for the four basins. Carbon emission in Henan increased from 134.46 million tons in 1990 to 553.58 million tons in 2018, while its carbon absorption was relatively stable (1.67–1.69 million tons between 1990 and 2018). The carbon emitted in the Huai River Basin was the main contributor to Henan Province’s total carbon emission. The carbon absorption in Yellow River Basin and Yangtze River Basin had an obvious spatial agglomeration effect. Finally, considering the current need of land spatial planning in China and the goal of carbon neutrality by 2060 set by the Chinese government, we suggested that carbon sequestration capacity should be further strengthened in Yellow River Basin and Yangtze River Basin based on their respective ecological resource advantages. For future development in Hai River Basin and Huai River Basin, coordinating the spatial allocation of urban scale and urban green space to build an ecological city is a key direction to embark upon.

Superhydrophobic substrate is applied in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) detection due to its confinement effect. The weak interaction of superhydrophobic surface with water/salts makes it potential in one-step enrichment and desalting of peptide in MALDI MS analysis. We fabricate a superhydrophobic substrate by spin-coating poly(dimethyl siloxane) (PDMS) on a candle soot layer. On this substrate, the peptide analytes can be confined and enriched in a small area due to the confinement effect and its strong hydrophobic interactions with PDMS. Meanwhile, the desalting can be easily realized by removing the residual solution after the absorption of analyst molecules due to the weak interaction between water/salt contaminants and the superhydrophobic surface. Using this substrate, angiotensin III (Ang III) in the presence of salt with high concentration (2 M or saturated) can be analyzed, and the peptide sequence coverage of 10 μg/mL myoglobin (MYO) and bovine serum albumin (BSA) digests is enhanced to 51% and 26%, which is 37% and 21% analyzed with the commercial ZipTipC18 pipette tips. The LOD of bacitracin A (Bac A) in milk with this substrate is 100 pM and nearly 360 times lower than the LOD of standard testing method. This substrate has potential practical applications in proteomics research and actual sample analysis.

With the rapid progress of urbanization, the loss of cultivated land has attracted great attention worldwide, and economic compensation is one of the incentives commonly used by the governments to enhance farmers&rsquo, enthusiasm in protecting cultivated land. In recent years, although various economic compensation modes have been implemented by the Chinese government, such modes are still experimental and exploratory. Thus, designing and implementing a national economic compensation mode is urgent to effectively protect the quantity and quality of cultivated land. This study focuses on the mode of cultivated land protection fund (CLPF) in Chengdu, which is the earliest mode of the implementation of economic compensation in China in 2008. First, we analyzed the farmers&rsquo, satisfaction with the CLPF through a face-to-face interview with 296 farmers in Chengdu. Then, we used the path analysis method to identify the influencing factors of farmers&rsquo, satisfaction from the characteristics of farmers and the policy. Results show that the CLPF was generally supported by farmers. Nevertheless, room for improvement still exists. Particularly, farmers&rsquo, satisfaction was low in the design of the government&rsquo, s supervision management of the CLPF. Farmers&rsquo, satisfaction with compensation standard, funding use requirement, and the government&rsquo, s supervision management were remarkably affected by factors, including farmers&rsquo, educational level, cultivated land area, total annual agricultural income, farmers&rsquo, knowledge of the CLPF, farmers&rsquo, recognition of the value of the CLPF, and farmers&rsquo, perception of the changes in household economics. Particularly, the direct influence of farmers&rsquo, perception of the changes in household economics was the most important. Finally, we proposed the recommendations for constructing a national economic compensation mode for cultivated land protection. Our results have certain guiding significance for promoting the sustainable development of cultivated land protection policies by means of economic incentives in China and other countries.

An array of plasmonic opposite metal spindles in nanowells is fabricated for sensing. This array is fabricated based on the combination of nanoimprint lithography and two-step shadow deposition, which exhibits a remarkable plasmonic sensing property and SERS activity. This method can be applied to the preparation of plasmonic structures for detecting and sensing applications.

The reduction of surface reflectivity is an important approach to improve the performance of optical and optoelectronic devices. Herein, we greatly suppressed the reflectivity of the silicon surface by ordered silicon nanopillar arrays, which were fabricated by metal-assisted chemical etching. The average reflectivity of the silicon surface was suppressed to lower than 0.1% from 45% at the wavelength range of 250–1050 nm, and it remained below 1.2% when the incident angle changed from 0° to 70°. We investigated the effect of the height and diameter of the nanopillars on the reflectivity, which revealed that the reflectivity decreased with increasing height of the nanopillars, and the reflectivity peaks blue shifted with the reducing nanopillar diameter. The results indicate that the antireflection performance can be tuned by adjusting the height and diameter of nanopillars. Therefore, this method may provide an approach to reduce and tune the reflection of Si surfaces.

Improving hot-spot intensity is a key issue in surface-enhanced Raman scattering (SERS). The bowtie nanoantenna (BNA) is an effective device used to concentrate light energy into a nanoscale volume and produce strong hot spots. Nanosphere lithography (NSL) is a large-area and low-cost technique to produce BNA arrays; however, the SERS activity of NSL-fabricated BNAs is limited. In this paper, we present a simple method to improve the SERS activity of conventional NSL-fabricated BNAs by modifying their geometry. The new configuration is termed “silver-coated elevated bowtie nanoantenna” (SCEBNA). SCEBNAs perform intensive near-field enhancement in the gap cavities owing to the integrated contribution of the “lightning rod” effect, resonance coupling, and the formation of the plasmonic Fabry–Perot cavity. Experimental measurements and finite-difference time-domain simulations revealed that the hot-spot intensity and the substrate enhancement factor can be optimized by adjusting the silver thickness. The optimal sample has the capability of trace-amount detection with fine reproducibility.

The ability to regulate the tilt angle of Si nanostructures is important for their applications in photoelectric devices. Herein we demonstrate a facile method to precisely regulate the tilt angle of nanocones with metal-assisted chemical etching (MaCE) in a one-step process based on the systematic investigation of the formation mechanism of the tilt angle. With Au nanohole arrays as templates, the tilt angles of Si nanocone arrays can be tuned from 69.2° to 88.6° by varying the composition of the etchant. When the Si nanocone arrays are the same height (2.2 μm), the reflectivity decreases with the decreasing of the tilt angle. When the tilt angle is 83.0°, the average reflectivity is lowered to 1.37% in the 250–1000 nm range. This method can be applied for fabrication over a large area (as large as 2 cm × 2 cm). This chemical method should be applicable to other Si nanostructures, which may promote the applications of MaCE in semiconductor manufacturing.