Characteristics of multiple‐year nitrous oxide emissions from conventional vegetable fields in southeastern China

The annual and interannual characteristics of nitrous oxide (N2O) emissions from conventional vegetable fields are poorly understood. We carried out 4 year measurements of N2O fluxes from a conventional vegetable cultivation area in the Yangtze River delta. Under fertilized conditions subject to farming practices, approximately 86% of the annual total N2O release occurred following fertilization events. The direct emission factors (EFd) of the 12 individual vegetable seasons investigated ranged from 0.06 to 14.20%, with a mean of 3.09% and a coefficient of variation (CV) of 142%. The annual EFd varied from 0.59 to 4.98%, with a mean of 2.88% and an interannual CV of 74%. The mean value is much larger than the latest default value (1.00%) of the Intergovernmental Panel on Climate Change. Occasional application of lagoon‐stored manure slurry coupled with other nitrogen fertilizers, or basal nitrogen addition immediately followed by heavy rainfall, accounted for a substantial portion of the large EFds observed in warm seasons. The large CVs suggest that the emission factors obtained from short‐term observations that poorly represent seasonality and/or interannual variability will inevitably yield large uncertainties in inventory estimation. The results of this study indicate that conventional vegetable fields associated with intensive nitrogen addition, as well as occasional applications of manure slurry, may substantially account for regional N2O emissions. However, this conclusion needs to be further confirmed through studies at multiple field sites. Moreover, further experimental studies are needed to test the mitigation options suggested by this study for N2O emissions from open vegetable fields

The Effects of Land-Use Change/Conversion on Trade-Offs of Ecosystem Services in Three Precipitation Zones

Revealing the spatial differentiation of ecosystem service (ES) trade-offs and their responses to land-use change along precipitation gradients are important issues in the Loess Plateau of China. We selected three watersheds called Dianshi (300 mm < MAP (mean annual precipitation) < 400 mm), Ansai (400 mm < MAP < 500 mm), and Linzhen (500 mm < MAP < 600 mm). A new ES trade-off quantification index was proposed, and quantile regression, piecewise linear regression, and redundancy analysis were used. The results were as follows. (1) Carbon sequestration (TC) and soil conservation (SEC) increased, but water yield (WY) decreased in the three watersheds from 2000 to 2018. (2) The effect of forests on trade-offs was positive in three watersheds, the main effect of shrubs was also positive, but the negative effect appeared in the TC-WY trade-off in Ansai. Grassland exacerbated trade-offs in Dianshi, whereas it reduced trade-offs in Ansai and Linzhen. These effects exhibited respective trends with the quantile in the three watersheds. (3) There were threshold values that trade-offs responded to land-use changes, and we could design land-use conversion types to balance ESs. In general, the water consumption of grass cannot be ignored in Dianshi; shrubs and grass are suitable vegetation types, and forests need to be restricted in Ansai; more forests and shrubs can be supported in Linzen due to higher precipitation, but the current proportions of forests and shrubs are too high. Our research contributes to a better understanding of the response mechanisms of ES trade-offs to land-use changes

The Transition of Cultural Ecology in Beidong District of Guizhou – A Case Study of Tianzhu Community

Beidong minorities living together in Qingshui River valley are deeply influenced by Jing and Chu culture. Their ethnic and traditional culture was developed in the process of collision with foreign culture. In the several great social transformations, their cultural ecology was not imbalanced, but evolved and developed. Through the study on local knowledge of cultural ecology including agricultural production, ancestral hall and local-style dwelling house, full-scale drama and Yang Drama, genealogical system, marriage customs, religious belief, sacrificial rites and funeral rites, it is expected to reveal reasons and rules of transition of Beidong ethnic culture, favorable for correctly understanding cultural connotation and promote cultural and tourism development in ethnic minority areas

The Effects of Land-Use Change/Conversion on Trade-Offs of Ecosystem Services in Three Precipitation Zones

Revealing the spatial differentiation of ecosystem service (ES) trade-offs and their responses to land-use change along precipitation gradients are important issues in the Loess Plateau of China. We selected three watersheds called Dianshi (300 mm < MAP (mean annual precipitation) < 400 mm), Ansai (400 mm < MAP < 500 mm), and Linzhen (500 mm < MAP < 600 mm). A new ES trade-off quantification index was proposed, and quantile regression, piecewise linear regression, and redundancy analysis were used. The results were as follows. (1) Carbon sequestration (TC) and soil conservation (SEC) increased, but water yield (WY) decreased in the three watersheds from 2000 to 2018. (2) The effect of forests on trade-offs was positive in three watersheds, the main effect of shrubs was also positive, but the negative effect appeared in the TC-WY trade-off in Ansai. Grassland exacerbated trade-offs in Dianshi, whereas it reduced trade-offs in Ansai and Linzhen. These effects exhibited respective trends with the quantile in the three watersheds. (3) There were threshold values that trade-offs responded to land-use changes, and we could design land-use conversion types to balance ESs. In general, the water consumption of grass cannot be ignored in Dianshi; shrubs and grass are suitable vegetation types, and forests need to be restricted in Ansai; more forests and shrubs can be supported in Linzen due to higher precipitation, but the current proportions of forests and shrubs are too high. Our research contributes to a better understanding of the response mechanisms of ES trade-offs to land-use changes

Bacterial Acclimation Inside an Aqueous Battery.

Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm(-2) and 1.4-2.1 V. Bacterial addition within 1.0×10(10) cells mL(-1) did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms

Reminiscence and Introspection: Influence of Tourism Memory Construction on Expansion of Individual Self-Concept

Memory is an essential structure of the tourism experience. Tourism memory construction is not only an individual's review and sublimation of on-site experience, but also the pursuit and introspection of self-meaning. Although tourism memory is unique and critical, it has not yet been fully examined in local tourism studies, resulting in the focus on on-site experience while ignoring the special role of tourism memory in shaping the landscape and constructing individual self-cognition. In this study, based on theories of autobiographical memory and self-expansion, the Grounded Theory and Structural Equation Model were adopted to investigate the influence mechanism of tourism memory construction on tourists' self-concept expansion based on excavating the dimensions of tourism memory construction. The results showed that: 1) Tourism memory is an unforgettable autobiographical memory formed by individual screening and construction after tourists' on-site experience. Its construction dimensions comprise three basic structures: cognitive appraisal, interactive perception, and affective involvement. Specifically, cognitive appraisal refers to the cognitive feelings generated by tourists based on the objective environment of destinations in their memory. Interactive perception is the participatory perception of the interaction between the host and guest and the interaction between tourists. Affective involvement reflects the emotional properties of memory, which is the corresponding emotional reaction of tourists based on cognitive appraisal and interactive perception. These three elements are interrelated and jointly shape and interpret the landscape constructing tourist' self-identity. 2) Cognitive appraisal, interactive perception, and positive affective involvement in tourism memory help promote tourism-sharing behavior, which significantly and positively influences the individual and social self-expansion of tourists. This finding confirms that cognitive and interactive memories contribute to tourism-sharing behavior. In particular, positive and negative affective involvements are remembered by tourists, but many tourists are more willing to share "positive energy" and express the positive side of tourism memories. In addition, through self-narration and self-expression, tourism sharing deepens reflection of the overall self-perception. 3) Among the direct effects of tourism memory construction on self-concept expansion, cognitive appraisal and interactive perception significantly and positively affect individual and social self-expansion, whereas positive affective involvement only positively affects individual self-expansion and indirectly affects social self-expansion by tourism sharing. Furthermore, this paper theoretically clarifies the dimensions of tourism memory construction, complements the theoretical deficiencies of post-travel memory in previous tourism experience studies, and reveals the subjective significance of tourism memory to self. This paper also introduces the concept of self-expansion in tourism research and complements self-expansion studies in nonrelational contexts. Finally, this study is a practical reference for memory marketing in destinations

Spatial distribution and tourism competition of intangible cultural heritage: take Guizhou, China as an example

Abstract As a province inhabited by ethnic minorities in southwest China, Guizhou is rich in tourism and ICH (intangible cultural heritage) resources. The spatial distribution of ICH and the utilization of tourism and ICH resources in Guizhou worth studying, which is better for understanding the tourism competition situation and the tourism utilization of ICH. This research uses GIS tools for spatial analysis, mathematical formulas for calculating the abundance of ICH and tourism resources, as well as the matrix analysis for ICH and tourism competition, to identify the spatial distribution and tourism competition situation of ICH in Guizhou Province in 2019. The results show that: (1) in terms of the structural characteristics of the number and types of ICH in Guizhou Province, folk custom, traditional craftsmanship and traditional music have the highest number and proportion, while Quyi has the lowest. (2) Grade A scenic spots are mainly located in Zunyi City, while ICH scenic spots are mainly in Southeast Guizhou, Zunyi City, South Guizhou and Southwest Guizhou. Zunyi City ranks first in the abundance of tourism resources, and Liupanshui City ranks last. Southeast Guizhou has the highest ICH resources abundance, while Liupanshui City has the lowest. (3) Both the distribution of national-level and provincial-level ICH in Guizhou are aggregated. The national-level ICH are clustered in a large core area in geographical space, which is located in the southeast of Guizhou. The provincial-level ICH sites form a belt extending from southwest to southeast of the province, which is distributed at the junction of southeast of Guizhou, Guiyang and Anshun. (4) The provincial-level ICH in Guizhou has formed a belt-like high-density zone extending from southwest to southeast and three high-density core areas. (5) Through the analysis of a tourism competition matrix, we found that there are three types of development in nine cities in Guizhou Province. Zunyi City and Southeast Guizhou show the development characteristics of “tourism prosperity-ICH tourism prosperity”. Guiyang, Bijie, Anshun, Southwest Guizhou, Liupanshui and Tongren City show the development characteristics of “tourism depression-ICH tourism depression”. South Guizhou shows “tourism depression-ICH tourism prosperity”. These findings and methods will help cities determine their own strengths and weaknesses according to their resources, and narrow the regional development gap through formulating cultural and tourism development plans

Fe2O3/Porous Carbon Composite Derived from Oily Sludge Waste as an Advanced Anode Material for Supercapacitor Application

It is urgent to improve the electrochemical performance of anode for supercapacitors. Herein, we successfully prepare Fe2O3/porous carbon composite materials (FPC) through hydrothermal strategies by using oily sludge waste. The hierarchical porous carbon (HPC) substrate and fine loading of Fe2O3 nanorods are all important for the electrochemical performance. The HPC substrate could not only promote the surface capacitance effect but also improve the utilization efficiency of Fe2O3 to enhance the pseudo-capacitance. The smaller and uniform Fe2O3 loading is also beneficial to optimize the pore structure of the electrode and enlarge the interface for faradaic reactions. The as-prepared FPC shows a high specific capacitance of 465 F g&minus;1 at 0.5 A g&minus;1, good rate capability of 66.5% retention at 20 A g&minus;1, and long cycling stability of 88.4% retention at 5 A g&minus;1 after 4000 cycles. In addition, an asymmetric supercapacitor device (ASC) constructed with FPC as the anode and MnO2/porous carbon composite (MPC) as the cathode shows an excellent power density of 72.3 W h kg&minus;1 at the corresponding power density of 500 W kg&minus;1 with long-term cycling stability. Owing to the outstanding electrochemical characteristics and cycling performance, the associated materials&rsquo; design concept from oily sludge waste has large potential in energy storage applications and environmental protection

Bacterial Acclimation Inside an Aqueous Battery - Fig 1

<p>A. battery performance by using 0.1 M LiCl plus 0.1 M ZnCl₂, pH 6.12 as the electrolyte; B. Effects of different bacterial media on battery cycling.</p

Effect of bacteria addition on battery performance.

<p>Effect of bacteria addition on battery performance.</p