The fractional differential equation is used to quantify the cost management system of Chinese cross-border e-commerce enterprises. At the same time, the influence mechanism of this system is ...preliminarily explored in this paper. Then this paper makes quantitative and simulation tests on the balance and stability of the cost control system of cross-border e-commerce. At the end of the report, the impact of new laws and regulations on the cost control of international e-commerce in China is analyzed. The results show that multinational e-commerce can make Chinese export gain more significant development in expanding margin and intensive margin. It is more evident in developing marginal effect but lags in intensifying marginal effect.
•Developed a spatially explicit approach to mapping supply and demand of CESs.•The approach integrated the SolVES model and social media comments.•Almost 70% of the study area, including protected ...areas, supply exceeded demand.•Protected areas internal Supply and demand exceeded the external.•Areas surrounding protected areas should also be considered.
The construction of protected areas (PAs) is not only the most effective way to preserve biodiversity resources and the natural heritage, but also provides important cultural ecosystem services (CESs) for satisfying human psychological and spiritual needs and improving human well-being. Knowledge of CESs at the county level is vital for the bottom-up promotion of the overall work of China’s PAs. The assessment and mapping of the spatial pattern of CESs, and their supply and demand relationship in PAs and their surrounding areas, are of great significance for high-quality development planning at the county scale. In our study, we developed an integrated approach to mapping the supply and demand of CESs, and then integrated the SolVES model with social media comments to explore the matching relationship between CESs’ (aesthetic inspiration, education humanities, and recreation and ecotourism) supply and demand using Wuyishan City, China, with its abundant PAs, as a case study. The results showed that the supply of three types of CESs accounting for approximately 70% of the study area was greater than the demand, and thus these CESs have significant future development prospects. The distribution of the three high-supply CESs and tourist destinations showed roughly the same spatial patterns, in which the high-demand hot spots were identified in the south of Wuyishan City. And the total supply and demand levels inside the PAs were much greater than those outside. Therefore, clarifying the matching relationship between supply and demand of CESs at the county level is not only conducive to promoting the sustainable development of natural resources, but also provides a reference for the planning of county-level protection of PAs under each county’s jurisdiction.
Stomata are important indexes in studies of plant origin, evolution, and classification and are important organs in plant phylogenetic relationship studies. Nine Aleurites montana provenances were ...used in this study to examine stomatal density, stomatal area, stomatal perimeter, long axis length, and short axis length. The correlation and cluster analyses were conducted among the morphological parameters of the pores. The results showed that there were significant differences in different A. Montana provenances in terms of stomatal morphology parameters. The average stomatal density, stomatal area, stomatal perimeter, stomatal long axis length, and stomatal short axis length of each provenance was between 224.16-307.10 stomata/mm2, 80.42-99.76 μm, 36.39-41.32 μm, 15.89-18.44 μm, and 6.53-7.46 μm, respectively, and the coefficient of variation was between 9.18%-20.15%, 17.57%-33.77%, 9.31%-18.79%, 9.71%-18.48%, and 10.26%-21.57%, respectively. Correlation analysis shows that there was a significant negative correlation between stomatal density and stomatal shape parameters (stomatal area, stomatal perimeter, stomatal long axis, stomatal short axis) and there was a significant positive correlation between stomatal parameters. There was no significant correlation between geographical environment factors and stomatal characteristics. There is a close relationship between stomatal morphology and stomatal conductance whereby dense small stomata can quickly adapt to changes in the environment; considering the characteristics A. montana stomata in terms of stomatal stability and ability to adapt to the environment, the Jianyang, Zhenghe, Fuding, Shaxian provenances were identified as being more suitable for planting at different sites. This study provides a theoretical basis for the genetic improvement and breeding of high quality A. montana provenances.
Abstract
This research investigates how secrecy (i.e., a state in which people have an active intention to conceal information from others) affects individuals’ consumption behavior. Six studies ...reveal that making consumers’ secrets salient increases their tendency to conform in their consumption and show that this effect is driven by the desire to avoid social attention. This effect is moderated by consumers’ perceived self-control capacity. This research uncovers a novel downstream consequence of secrecy on consumer behavior and provides insight into when conforming consumption can serve as a strategy to help consumers avoid unwanted social attention. This research has important practical implications concerning using notions of secrecy in marketing strategies and promoting conforming products.
The evaluation of ecosystem health is a hotspot in macro-ecology and ecosystem management. The objective of this paper is to introduce an ecosystem health assessment framework that combines ecosystem ...service concepts and indicators. We analyzed ecological services on Dongshan Island for regulating heavy rainfall by explicitly addressing the spatial distribution of ecosystem service demand and supply. An index system was then developed for both the areas that provide the ecological service and those that benefit from it. These areas are linked by small watersheds that were extracted using the hydrological analysis function in ArcGIS 10.2. Weights of the indicators were assigned and calculated based on principal component analysis. Finally, at the small watershed scale, the forested area and “other” land area ratios were weighted to assess the overall health of the areas that provide and benefit from this ecological service. The results revealed that the forest health conditions in the northwestern and northern parts of the island were weak, especially in the vicinity of the county seat. The analysis indicated that forested areas in the regions were relatively small, and the functional ecological service related to the redistribution of rainfall provided by these forested areas was minimal. The health states of areas benefiting from this ecological service generally appeared problematic. Areas benefiting from the service were characterized by dense populations, intense urbanization, and high risk of rain-related disaster. Moreover, only small and scattered forests were observed in the urban areas and towns on Dongshan Island. These urbanized areas rarely support large forest patches, and they fail to provide adequate green corridors or significant green space. This forest condition in urban areas cannot provide commendably protective functionality to mitigate heavy rain disasters. Therefore, to improve the ecological health of Dongshan Island, a system of green areas within urban landscapes must be planned and developed.
Compacted bentonite-sand blocks have been proposed to construct buffer barriers in high-level radioactive waste (HLW) repositories in order to isolate wastes. The bentonite-based blocks are usually ...manufactured by uniaxial compression in mould and exhibit anisotropic behavior, which may influence the buffer performance. This current paper aims at investigating the anisotropic hydro-mechanical behavior of full-scale compacted bentonite-sand blocks. The 1/12 block rings were axially compressed in a mould with 170 and 475 mm in radiuses and 100 mm in height, and the density distribution was examined by computed tomography (CT). The block's engineering performance was monitored in different directions, including the drying shrinkage and crack development during the storage, and the swelling pressure and hydraulic conductivity during hydration. The blocks' surface shrinkage strain was measured by the digital image correlation (DIC), and the surface cracks were analyzed by an image-processing technique. In addition, subsamples were excavated from replicate blocks to measure their hydraulic conductivity and swelling pressure in different directions. The blocks showed anisotropic properties, such as the less shrinkage strain and higher swelling pressure in the vertical load direction, and the appearance of nearly horizontal cracks. In contrast, the hydraulic conductivity of the blocks was similar in the vertical and horizontal directions. The horizontally oriented smectite plates and bentonite aggregations, as verified by the scanning electron microscope (SEM) images and development of swelling pressure, contributed to blocks' anisotropic behavior. On the other hand, the sand and incompressible impurities created preferential flow paths for their isotropic permeation.
•The homogeneous full-scale compacted bentonite-sand blocks have been produced;•The block's shrinkage, crack development, and swelling pressure are anisotropic;•Particle orientation contributes to the block's anisotropic behavior;•The block's permeability is isotropy due to the sand and incompressible impurities.
The exotic saltmarsh cordgrass,
Spartina alterniflora
(Loisel) Peterson & Saarela, is one of the important causes for the extensive destruction of mangroves in China due to its invasive nature. The ...species has rapidly spread wildly across coastal wetlands, challenging resource managers for control of its further spread. An investigation of
S. alterniflora
invasion and associated ecological risk is urgent in China’s coastal wetlands. In this study, an ecological risk invasive index system was developed based on the Driving Force-Pressure-State-Impact-Response framework. Predictions were made of ‘warning degrees’: zero warning and light, moderate, strong, and extreme warning, by developing a back propagation (BP) artificial neural network model for coastal wetlands in eastern Fujian Province. Our results suggest that
S. alterniflora
mainly has invaded
Kandelia candel
beaches and farmlands with clustered distributions. An early warning indicator system assessed the ecological risk of the invasion and showed a ladder-like distribution from high to low extending from the urban area in the central inland region with changes spread to adjacent areas. Areas of light warning and extreme warning accounted for 43% and 7%, respectively, suggesting the BP neural network model is reliable prediction of the ecological risk of
S. alterniflora
invasion. The model predicts that distribution pattern of this invasive species will change little in the next 10 years. However, the invaded patches will become relatively more concentrated without warning predicted. We suggest that human factors such as land use activities may partially determine changes in warning degree. Our results emphasize that an early warning system for
S. alterniflora
invasion in China’s eastern coastal wetlands is significant, and comprehensive control measures are needed, particularly for
K. candel
beach.
Key message
The spatiotemporal patterns and strength of
Dendrolimus punctatus
Walker attacks were identified at the landscape level. Climate factors influenced pest damage more than stand or ...topographic factors.
Dendrolimus punctatus
Walker (Lepidoptera: Lasiocampidae) routinely infests pine species in southern China and inflicts heavy damage on resources or monetary earnings. Evidence is required to facilitate a better understanding of spatiotemporal infestation patterns at the landscape level and the influence of various factors on its outbreaks from multiple spheres. We quantified the landscape-level spatiotemporal pattern of
D. punctatus
occurrence and examined the impacts of climate, stand and topographical factors on pest infestations in a
Pinus massoniana
natural forest in a mixed world heritage site in southeastern China. Our findings indicated that pest infestations had a relatively strong temporal continuity and a weak spatially aggregated distribution at a landscape level. Multivariate statistical analysis showed that climate variables had a greater influence on the degree of damage caused by
D. punctatus
infestations than stand or topographical variables. A decrease in annual average precipitation or humidity may cause an increased risk of pest outbreaks.
Kandelia candel is the most widely distributed tree species on the southeast coast of China and is also the main afforestation tree species along the coastal wetland. In recent years, inorganic ...nitrogen pollution has become increasingly severe, and investigating the effects of nitrogen input on methane emissions in Kandelia candel–soil systems has become significant from a global change perspective. However, the effect of nitrogen input on methane emissions in coastal wetland systems is still uncertain. The field tidal environment is complex and varied, and thus it is difficult to accurately control the amount of nitrogen in the system. Therefore, in order to accurately assess the effects of different concentrations of foreign nitrogen input on methane emission fluxes in a Kandelia candel–soil system, we use indoor tidal simulation experimental devices and design two simulation systems with and without plant planting to explore the difference of methane emission flux in this system under five nitrogen input concentrations: N0 (0 g N·m−2·a−1), N1 (5 g N·m−2·a−1), N2 (10 g N·m−2·a−1), N3 (20 g N·m−2·a−1), and N4 (30 g N·m−2·a−1). The results showed that: (1) The introduction of Kandelia candel promoted methane emissions in coastal wetland ecosystem. Under each nitrogen application concentration, the mean CH4 emission flux in the planting group was 42.98%, 65.59%, 40.87%, 58.93% and 39.23% higher than that in the non-planting group, respectively. (2) Nitrogen input significantly promoted methane emissions in both planted and non-planted environments, and the promoting effect showed as follows: N4 > N3 > N2 > N1 > N0. (3) After the introduction of Kandelia candel, the contribution of Kandelia candel and soil microorganisms to methane emissions was different under different concentrations of nitrogen addition. The contribution rate of Kandelia candel to CH4 emission flux of Kandelia candel–soil system ranged from 10.74% to 60.25%, with an average contribution rate of 37.30%. The changed soil microbes contributed 39.75% to 89.26% to the CH4 emission flux in the Kandelia candel–soil system, with an average contribution rate of 62.60%. Under N3 nitrogen application concentration, the emission flux of plant was the largest, which was significantly higher than that of the soil microbial pathway; at other concentrations, the methane emissions from the soil microbial pathway were greater than that of the plant pathway, and the contribution rate to the plant–soil system reached 60.25%. The results of this study provide an important basis for improving the estimation accuracy of carbon emissions in coastal waters and formulating policies for the restoration and protection of coastal wetlands.
The rhizosphere, distinct from bulk soil, is defined as the volume of soil around living roots and influenced by root activities. We investigated protease, invertase, cellulase, urease, and acid ...phosphatase activities in rhizosphere and bulk soils of six Nothotsuga longibracteata forest communities within Tianbaoyan National Nature Reserve, including N. longibracteata ＋ either Phyllostachys pubescens, Schima superba, Rhododendron simiarum, Cunninghamia lanceolata, or Cyclobalanopsis glauca, and N. longibracteata pure forest. Rhizosphere soils possessed higher protease, invertase, cellulase, urease, and acid phosphatase activities than bulk soils. The highest invertase, urease, and acid phosphatase activities were observed in rhizosphere samples of N. longibracteata ＋ S. superba. Protease was highest in the N. longibracteata ＋ R. simiarum rhizosphere, while cellulase was highest in the pure N. longibracteata forest rhizosphere. All samples exhibited obvious rhizosphere effects on enzyme activities with a significant linear correlation between acid phosphatase and cellulase activities （p 〈 0.05） in rhizosphere soils and between protease and acid phosphatase activities （p 〈 0.05） in bulk soils. A principal component analysis, correlating 13 soil chemical properties indices relevant to enzyme activities, showed that protease, invertase, acid phosphatase, total N, and cellulase were the most important variables impacting rhizosphere soil quality.
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