Rethinking urban wilderness: Status, hotspots, and prospects of ecosystem services.

An urban wilderness (UW) portrays a coupled relationship between natural dominance and human management in urban spaces. Superior ecosystem services support sustainable urban development. Systematic assessments of the status, changes, and trends of urban wilderness ecosystem services (UWESs) are a debated and complex issue in the field of ecology despite their importance as key components for ensuring the sustainable development of human society. We aimed to analyze the scientific literature on UWESs published between 2000 and 2022. Hence, we used bibliometric methods to comprehensively understand the research lineages, hotspots, and trends in UWESs. We found that the research has roughly encompassed two phases: initial exploration (2000-2011)and rapid growth (2012-2022). The number of publications has shown a continuous growth trend; the research hotspots include UWs compared with urban greenfield ecosystems, the spatio-temporal dynamics of UWs, ecosystem services and value assessments, and the coupling and linkage between ecosystem maintenance and human health. We summarized relevant trends for the concept of harmonious coexistence between human beings and nature, focusing on spatio-temporal dynamics and multidisciplinary integration as well as reinforcing the link with human health. This study can serve as a reference for demonstrating the value of UWESs and their practical application in a UW.

Biotransformation of ethylene glycol by engineered Escherichia coli.

There has been extensive research on the biological recycling of PET waste to address the issue of plastic waste pollution, with ethylene glycol (EG) being one of the main components recovered from this process. Therefore, finding ways to convert PET monomer EG into high-value products is crucial for effective PET waste recycling. In this study, we successfully engineered Escherichia coli to utilize EG and produce glycolic acid (GA), expecting to facilitate the biological recycling of PET waste. The engineered E. coli, able to utilize 10 g/L EG to produce 1.38 g/L GA within 96 h, was initially constructed. Subsequently, strategies based on overexpression of key enzymes and knock-out of the competing pathways are employed to enhance EG utilization along with GA biosynthesis. An engineered E. coli, characterized by the highest GA production titer and substrate conversion rate, was obtained. The GA titer increased to 5.1 g/L with a yield of 0.75 g/g EG, which is the highest level in the shake flake experiments. Transcriptional level analysis and metabolomic analysis were then conducted, revealing that overexpression of key enzymes and knock-out of the competing pathways improved the metabolic flow in the EG utilization. The improved metabolic flow also leads to accelerated synthesis and metabolism of amino acids.

The environmental impact assessment of China's ecological migration from a social-ecological perspective.

When accounting for the social-ecological impact of an ecological restoration program, both objective environmental contexts and people's subjective perceptions are required. While this kind of environmental impact assessment lacks a comprehensive perspective. We use the difference-in-differences model to evaluate the effect of the greenness of the landscape after ecological migration in the Qilian Mountains in China; and analysis of variance and fixed effects models are used to evaluate the effects of such ecological restoration programs on local people's perceptions. The results show that the ecological migration program in the Qilian Mountains has been successful at not only significantly improving remotely sensed greenness at the landscape scale, but also at enhancing immigrants' environmental perceptions. These findings demonstrate the environmental impacts of ecological migration from a social-ecological perspective, and can provide methodological implications for landscape planning to support a better understanding of ecological restoration programs in the drylands.

Efficient isomerization of glucose into fructose by MgO-doped lignin-derived ordered mesoporous carbon.

The conversion of glucose into fructose can transform cellulose into high-value chemicals. This study introduces an innovative synthesis method for creating an MgO-based ordered mesoporous carbon (MgO@OMC) catalyst, aimed at the efficient isomerization of glucose into fructose. Throughout the synthesis process, lignin serves as the exclusive carbon precursor, while Mg2+ functions as both a crosslinking agent and a metallic active center. This enables a one-step synthesis of MgO@OMC via a solvent-induced evaporation self-assembly (EISA) method. The synthesized MgO@OMCs exhibit an impeccable 2D hexagonal ordered mesoporous structure, in addition to a substantial specific surface area (378.2 m2/g) and small MgO nanoparticles (1.52 nm). Furthermore, this catalyst was shown active, selective, and reusable in the isomerization of glucose to fructose. It yields 41 % fructose with a selectivity of up to 89.3 % at a significant glucose loading of 7 wt% in aqueous solution over MgO0.5@OMC-600. This performance closely rivals the current maximum glucose isomerization yield achieved with solid base catalysts. Additionally, the catalyst retains a fructose selectivity above 60 % even after 4 cycles, a feature attributable to its extended ordered mesoporous structure and the spatial confinement effect of the OMCs, bestowing it with high catalytic efficiency.

Identifying the Risk Regions of Wild Boar (Sus scrofa) Incidents in China.

The objectives of this study were to identify the risk regions of wild boar incidents in China and to draw a risk map. Risk maps can be used to plan the prioritization of preventive measures, increasing management effectiveness from both a short- and a long-term perspective. We used a web crawler (web information access technology) to obtain reports of wild boar incidents from China's largest search engine (Baidu) and obtained 196 valid geographic locations of wild boar incidents from the reports. Subsequently, a system of environmental variables-with climate, topography, landscape, and human disturbance as the main variable types-was constructed, based on human-land-system thinking. Finally, the Maxent model was applied to predict the risk space of wild boar incidents in China by integrating the geographic location information for wild boar incidents with the environmental variables. We observed that the types of environmental variables that contributed to wild boar incidents were in the descending order of climate (40.5%) > human disturbance (25.2%) > landscape (24.4%) > topography (9.8%). Among the 14 environmental variables, annual precipitation, the GDP index, and the mean annual temperature were the main environmental variables. The distance from woodland, distance from cultivated land, and elevation were the secondary environmental variables. The response curves of the environmental variables demonstrated that the highest probability of wild boar incidents occurred when the annual average temperature was 16 °C, the annual precipitation was 800 mm, and the altitudes were 150 m and 1800 m. The probability of wild boar incidents decreased with an increase in the distance from cultivated and forested land, and increased sharply and then levelled off with an increase in the GDP index. Approximately 12.18% of China was identified as being at a high risk of wild boar incidents, mainly on the eastern side of the Huhuanyong Line.

Catalytic hydrogenation of levulinic acid to γ-valerolactone over lignin-metal coordinated carbon nanospheres in water.

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) has attracted much attention, as GVL can be used as biofuel, green solvent, and platform chemical. Inspired by Stöber method, various lignin-metal coordinated colloidal nanospheres (LCS) from lignin and cetyltrimethylammonium bromide (CTAB) were synthesized in which the metal ions (Co2+) replace formaldehyde as the crosslinker. The characterization of the catalyst revealed that alkali lignin was first self-assembled with CTAB through electrostatic attraction to form a lignin polymer, the subsequent addition of metal ions (Co2+) promoted the aggregation of lignin polymers and generated the LCS. Increasing calcination temperature for LCS resulted in the Co2+ being reduced to metallic Co. The lignin-metal coordinated colloidal nanospheres calcined at 500 °C possess both CoO and metallic Co active sites, which effectively accelerated the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) than simplex metallic Co active sites. A 99.8 % yield of GVL with 100 % LA conversion was obtained after 60 min reaction time at 200 °C and 2 MPa H2.

Does Tobler's first law of geography apply to internet attention? A case study of the Asian elephant northern migration event.

One of the basic assumptions of spatial theory is formulated in Waldo Tobler's first law of geography: "everything is related to everything else, but near things are more related than distant things." However, as internet space is a complex virtual space independent of the real world, whether this law is applicable to things in the internet space remains to be explored in depth. Therefore, this study takes the event of Asian elephant northern migration as an example, attempts to investigate the issue of the applicability of Tobler's first law of geography to internet attention by integrating geographic methods such as spatial visualization, spatial correlation analysis, and Geo-detector. The results show that Tobler's first law of geography does not fully apply to internet attention, which does not decay with increasing distance. Geographical distance, within certain boundaries, is influenced by "identity" and "relevance", and still plays a large role in internet attention. However, once the boundaries are exceeded, the impact of geographic distance on internet attention is weakened by the intervention of influencing factors such as the degree of information technology, population, and the strength of news media publicity. Overall, the strength of news media publicity has the greatest impact on internet attention. And when it interacts with geographic proximity, it has the most significant effect on internet attention.

Synthesis of ultra-thin graphene-like nanosheets from lignin based on evaporation induced self-assembly for supercapacitors.

Graphene-like carbon materials are widely used in power devices due to their excellent structural characteristics. In this study, ultra-thin graphene-like nanosheets (LGLNs) with rich surface wrinkles were prepared by classical evaporation induced self-assembly (EISA) using lignin biomass as carbon precursor, followed by chemical activation with KHCO3. The obtained LGLN900 material calcined at 900 °C had a thickness of ca. 3 nm, a large specific surface area of 2886 m2 g-1 with a high specific pore volume of 2.10 cm3 g-1. In addition, a large number of wrinkles on the surface of LGLN900 endows its effective compression resistance. When the LGLN900 material was used as electrode material of supercapacitor, a high specific capacitance of 388 F g-1 was obtained at 0.2 A g-1 current density in 6 M KOH aqueous solution, and 269 F g-1 specific capacitance could be at remained at 40 A g-1. The supercapacitor assembled with LGLN900 afforded a specific energy density of (11.0-13.7) Wh kg-1 at a power density of (128.8-6465) W kg-1. This work provides a facile and green strategy for the synthesis of highly wrinkled ultra-thin graphene-like nanosheets from sustainable biomass resources, which should have wide applications in adsorption, catalysis and energy storage.

Electrocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid via metal-organic framework-structured hierarchical Co3O4 nanoplate arrays.

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was examined as an alternative to thermocatalytic methods in which two-dimensional (2D) cobalt-metal-organic framework (Co-MOF, ZIF-L-Co) nanoplate arrays were prepared on nickel foam (NF) and then transformed into hierarchical porous Co3O4 nanostructures by chemical etching and low temperature annealing to form electrode materials. Hierarchical porous nanoarrays formed during synthesis enlarged the surface area of the as-prepared catalysts introduced a large number of defects and exposed active sites leading to reduced charge diffusion, improved mass transfer and efficient HMF oxidation. Co3O4/NF electrode materials were able to achieve a current density of 10 mA·cm-2 at an overpotential of 105 mV in 1 M KOH with 10 mM HMF, which was reduced by 175 mV compared with water oxidation. Electrocatalytic oxidation experiments afforded 100 % HMF conversion and 96.7 % FDCA yields with a minimum 96.5 % faradaic efficiency at 1.43 V vs RHE. The proposed MOF-structured synthesis method fundamentally reduces charge diffusion, improves mass transfer of electrodes and is generally applicable to fabrication of hierarchical porous nanostructured materials.

Hierarchical nanoarchitectonics of ordered mesoporous carbon from lignin for high-performance supercapacitors.

The synthesis of ordered mesoporous carbons (OMCs) with hierarchical pore structure is significant for supercapacitor applications as electrode material. In this study, the ordered mesoporous carbons with hierarchical pore structure (HOMC) are synthesized via solvent evaporation induced self-assembly (EISA) method using lignin from walnut shell as carbon precursor and Co2+ ion as crosslinking agent, followed by removal of metal by diluted acid and chemical activation with KHCO3. The prepared HOMC material has a large specific surface area of 2033 m2 g-1 and high pore volume of 1.59 cm3 g-1, and it shows good electrochemical performance as the electrode of supercapacitor with high specific supercapacitances of 286 and 206 F g-1 in 6 M KOH aqueous solutions at 0.2 and 20 A g-1, respectively. The assembled HOMC-based symmetric supercapacitors provides a specific energy density of 13.5 Wh kg-1 at a high power density of 44.3 kW kg-1 and keep good cycling stability after 5000 cycle tests. The superior electrochemical performance is ascribed to the long range ordered parallel mesoporous channels, hierarchical porous structure, high specific surface area and appropriate microporous/mesoporous ratio. The materials prepared in this study have the potential to be used in the fields of adsorption, energy storage and capacitance deionization.

Synthesis of self-renewing Fe(0)-dispersed ordered mesoporous carbon for electrocatalytic reduction of nitrates to nitrogen.

In electrocatalytic reduction of nitrates to nitrogen, key issues are electrode activity, sustainable materials, preparation methods and cost. Herein, lignin, Fe3+ ion, and non-ionic surfactant were combined with evaporation-induced self-assembly (EISA) to prepare zero-valent Fe-dispersed ordered mesoporous carbon (OMC) electrode materials denoted as Fe#OMC. The method developed for preparing Fe-coordinated OMC material avoids the use of toxic phenols, aldehyde reagents and metal doping compounds. When synthesized Fe#OMC samples were applied as electrode materials for the electrocatalytic reduction of nitrate in aqueous solutions, maximum nitrate nitrogen removal was as high as 5373 mg N·g-1 Fe from aqueous solutions containing 400 mg·L-1 NO3--N, while nitrogen selectivity was close to 100%, exceeding catalytic performance of comparable materials. Active hydrogen produced by electrolysis of water during the reaction re-reduced Fe ions formed in the OMC material and stabilized Fe#OMC electrode performance and recycle. The Fe#OMC electrode is self-renewing with respect to its Fe zero-valent state, is simple to prepare from sustainable materials and is effective for electrocatalytic reduction of nitrate or nitrogen-containing compounds in water.

Synthesis of sulfonated lignin-derived ordered mesoporous carbon for catalytic production of furfural from xylose.

Sulfonated lignin-derived ordered mesoporous carbon (OMC-SO3H) solid acid was synthesized through solvent evaporation induced self-assembly (EISA) method followed by sulfonation, using lignin as carbon precursor and glyoxal as cross-linking agent during the preparation process. The as-synthesized OMC-SO3H exhibited a typical 2D hexagonal meso-structure (space group p6mm) and showed a good catalytic performance for the catalytic conversion of hemicellulose-derived xylose to furfural. A highest furfural yield of 76.7% with 100% xylose conversion was achieved at 200 °C for 45 min in γ-valerolactone (GVL)-water (85:15 v/v%) mixture. The lignin-derived OMC-SO3H solid acid catalyst showed superior stability and reusability, and was also applicable to the catalytic production of furfural from xylan. This work provides a promising strategy for the synthesis of ordered mesoporous carbon solid acid from green and sustainable lignin biomass resource, which has wide range of applications in the utilization of cellulose and hemicellulose.

Evaluation of PET Degradation Using Artificial Microbial Consortia.

Polyethylene terephthalate (PET) biodegradation is regarded as an environmentally friendly degradation method. In this study, an artificial microbial consortium composed of Rhodococcus jostii, Pseudomonas putida and two metabolically engineered Bacillus subtilis was constructed to degrade PET. First, a two-species microbial consortium was constructed with two engineered B. subtilis that could secrete PET hydrolase (PETase) and monohydroxyethyl terephthalate hydrolase (MHETase), respectively; it could degrade 13.6% (weight loss) of the PET film within 7 days. A three-species microbial consortium was further obtained by adding R. jostii to reduce the inhibition caused by terephthalic acid (TPA), a breakdown product of PET. The weight of PET film was reduced by 31.2% within 3 days, achieving about 17.6% improvement compared with the two-species microbial consortium. Finally, P. putida was introduced to reduce the inhibition caused by ethylene glycol (EG), another breakdown product of PET, obtaining a four-species microbial consortium. With the four-species consortium, the weight loss of PET film reached 23.2% under ambient temperature. This study constructed and evaluated the artificial microbial consortia in PET degradation, which demonstrated the great potential of artificial microbial consortia in the utilization of complex substrates, providing new insights for biodegradation of complex polymers.

Current Advances in the Biodegradation and Bioconversion of Polyethylene Terephthalate.

Polyethylene terephthalate (PET) is a widely used plastic that is polymerized by terephthalic acid (TPA) and ethylene glycol (EG). In recent years, PET biodegradation and bioconversion have become important in solving environmental plastic pollution. More and more PET hydrolases have been discovered and modified, which mainly act on and degrade the ester bond of PET. The monomers, TPA and EG, can be further utilized by microorganisms, entering the tricarboxylic acid cycle (TCA cycle) or being converted into high value chemicals, and finally realizing the biodegradation and bioconversion of PET. Based on synthetic biology and metabolic engineering strategies, this review summarizes the current advances in the modified PET hydrolases, engineered microbial chassis in degrading PET, bioconversion pathways of PET monomers, and artificial microbial consortia in PET biodegradation and bioconversion. Artificial microbial consortium provides novel ideas for the biodegradation and bioconversion of PET or other complex polymers. It is helpful to realize the one-step bioconversion of PET into high value chemicals.

Effect of Urban Greening on Incremental PM2.5 Concentration During Peak Hours.

In China, severe haze is a major public health concern affecting residents' health and well-being. This study used hourly air quality monitoring data from 285 cities in China to analyze the effect of green coverage (GC) and other economic variables on the incremental PM2.5 concentration (ΔPM2.5) during peak hours. To detect possible non-linear and interaction effect between predictive variables, a kernel-based regularized least squares (KRLS) model was used for empirical analysis. The results show that there was considerable heterogeneity between cities regarding marginal effect of GC on ΔPM2.5, which could potentially be explained by different seasons, latitude, urban maintenance expenditure (UE), real GDP per capita (PG), and population density (PD). Also described in this study, in cities with high UE, the growth of GC, PG, and PD always remain a positive impact on mitigation of haze pollution. This shows that government expenditure on urban maintenance can reduce or mitigate the environmental pollution from economic development. In addition, the influence of other urban elements on air quality had also been analyzed so that different combinations of mitigation policies are proposed for different regions in this study to meet the mitigation targets.

[Spatial Differentiation and Driving Analysis of Nitrogen in Rice Rotation Based on Regional DNDC: Case Study of Jinjiang River Watershed].

Cycling dynamics of nitrogen in paddy rotation areas have a practical significance for ensuring food supply and realizing sustainable development of the regional ecology in the Min delta urban agglomeration. However, with rapid urbanization, the negative externalities of paddy rotation areas have been gradually increased because of unreasonable utilization behavior, and the environmental costs are increasing. Therefore, the spatial differentiation of nitrogen indicators and its driving factors were analyzed, which provides a macro-decision making basis for the implementation of farmland management measures. In this study, the paddy rotation area in Jinjiang River watershed was selected as the research object. The denitrification decomposition (DNDC) model was used to simulate the nitrogen cycle in the paddy rotation area. The hot spot analysis and geographical weight regression (GWR) model were used to analyze the spatial otherness characteristics and driving attribution of various nitrogen indices. The main results showed that: ① The DNDC model was validated by parameters, and the results showed preferably regional adaptability. ② Based on the comparison of different rotation patterns, the rice-vegetable rotation pattern not only established the maximum input of nitrogen fertilizer but also revealed the highest nitrogen absorption efficiency and the maximum values of nitrogen loss, followed by the rice-rice rotation pattern and rice-fallow rotation pattern. ③ In the spatial distribution of nitrogen indicators, except for the crop nitrogen absorption, the NH3 emission, N2O emission and nitrogen leaching showed a spatial clustering distribution, and the main trend line based on the standard deviation ellipse was mainly "Gande-Changkeng" township.④ According to the analysis of spatial influence factors for various nitrogen indices, soil attribute factors had the strongest effect; the SOCmax was the strongest influential factor for both NH3 and N2O emissions, and the spatial distribution was "west high, east low". The pHmin was the strongest influential factor in nitrogen leaching, and the spatial distribution was "north and south high, east and west low".

Complete dechlorination of lindane over N-doped porous carbon supported Pd catalyst at room temperature and atmospheric pressure.

Transfer hydrogenation is highly effective for dechlorinating priority organic pollutants in wastewater. Lindane could be completely dechlorinated at room temperature and atmospheric pressure via transfer hydrogenation, in which Pd (3.1 wt%) supported on chitosan-derived porous carbon (3.1Pd@A600) and formic acid (FA) were used as catalyst and hydrogen source, respectively. Favorable catalytic activity of 3.1Pd@A600 is attributed to pyridinic N of the support that allowed Pd nanoparticles to be well-dispersed in the solid and to pyridinic N-Pd interactions that enhanced FA decomposition over that observed for commercial carbon supported Pd catalyst (5Pd@AC). In the reaction system containing 3.1Pd@A600 and FA, 99.7% lindane conversion and 100% dechlorination efficiency could be achieved at 25 °C and atmospheric pressure within 60 min. Benzene and cyclohexane were identified as end-products of lindane dechlorination. The transfer hydrogenation strategy developed in this study has wide application to chlorinated organic pollutants contained in actual waste streams.

Black liquor-derived calcium-activated biochar for recovery of phosphate from aqueous solutions.

Black liquor-derived calcium-activated biochars (Ca-biochar) were synthesized by treating rice straw with Ca(OH)2 to create an adsorbent that was effective for removing phosphate from aqueous waste streams. The Ca(OH)2 acts to separate lignin from the biomass, create pores in the biochar solids and form active adsorption sites. The Ca-biochar adsorbent was efficient for the removal of phosphate from aqueous solutions (pH 1.0 to pH 13.0) with a highest phosphate adsorption capacity of 197 mg/g. Phosphate adsorption was correlated with pseudo-second-order kinetics and the Langmuir model with primary mechanisms being attributed to chemical precipitation and ligand exchange. Application of the Ca-biochar (0.2 g/L) to actual wastewater from a cattle farm (phosphorus content 3.78 mg/L) reduced the phosphorus content to 0.021 mg/L. This work utilizes waste black liquor to prepare functionalized biochar materials, providing a promising approach for black liquor reuse and phosphate removal and recovery from phosphorus-rich waste streams.

Coupled Pretreatment with Liquid Nitrogen and Ball Milling for Enhanced Cellulose Hydrolysis in Water.

A key problem in the conversion of cellulose into chemicals and fuels is the low product yield from cellulose due to its robust structure. In this work, for the first time, cellulose was pretreated with coupling of liquid nitrogen and ball milling (LN-BM) for cellulose hydrolysis. After the LN-BM treatment, the glucose yield from cellulose by HCl in water increased by almost 2 times and yield of formic acid catalyzed by H2SO4-NaVO3 was more than 3-fold that obtained from untreated cellulose. The yields were also much higher than that from the individually ball-milled cellulose. The structure variation of cellulose indicated that reduction of both crystallinity index and molecular weight contributed to improving the conversion efficiency, but the former was the dominant factor. The combination of liquid nitrogen and ball milling developed in this work is an effective and environment-friendly approach for cellulose pretreatment.

Nonlinear temperature calibration equation for Rhodamine B in different solutions for wide-temperature-range applications.

In the two-color laser-induced fluorescence (LIF) ratio thermometry approach, accurate temperature calibration is the key for quantitative temperature measurement, especially in wide-temperature-range applications. In this work, the temperature behavior of Rhodamine B in two common solutions (aqueous and ethanol) in a wide temperature range (-30°C-90°C) is studied by spectroscopy methods. According to the spectral and two-color LIF ratio results, a nonlinear fitting method based on Arrhenius equation is presented for a calibration equation. Compared with the traditional linear fitting model, improved accuracy at a temperature of 2°C-3°C can be achieved even at low sensitivity. Considering the nonlinear temperature behavior of Rhodamine B, this method can achieve a higher temperature sensitivity at a lower temperature, further demonstrating the feasibility of this method for low-temperature applications.