Abstract
Ozone (O
3
) in the troposphere is an air pollutant and a greenhouse gas. In mainland China, after the Air Pollution Prevention and Action Plan was implemented in 2013—and despite ...substantial decreases in the concentrations of other air pollutants—ambient O
3
concentrations paradoxically increased in many urban areas. The worsening urban O
3
pollution has fuelled numerous studies in recent years, which have enriched knowledge about O
3
-related processes and their impacts. In this article, we synthesise the key findings of over 500 articles on O
3
over mainland China that were published in the past six years in English-language journals. We focus on recent changes in O
3
concentrations, their meteorological and chemical drivers, complex O
3
responses to the drastic decrease in human activities during coronavirus disease 2019 lockdowns, several emerging chemical processes, impacts on crops and trees, and the latest government interventions.
To understand rural sustainability, it is necessary to scrutinize the relationship between rural transition and economic growth. The article uses rural multifunctionality as an analytical lens ...through which to view the processes of the development of rural occupancy. There is a pressing need to ascertain how to quantify rural multifunctionality and reveal its spatial differentiation, as well as garner and investigate how multifunctional rural transition (MRT) responds to economic growth. This paper employed the concept of sample transect to compensate for data deficiencies in a long temporal series and established the indicator system from three different aspects-living function, production function, and ecological function-to measure MRT along China’s Yangtze River Transect. Our analysis showed that living function and production function display an increasing trend from underdeveloped western regions to eastern economically prosperous regions, and represent a high degree surrounding urban agglomerations, while economic growth only leads to a statistically insignificant decreasing trend in ecological function. The MRT resulting from multiple factors is much diverse, complex, and sophisticated; therefore, it should be understood within a framework incorporating both endogenous and exogenous factors. According to the results, it is thus important to formulate differentiated managerial countermeasures corresponding to the economic development level rather than the uniform regulations.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With the introduction of the concept of land use transition into China, related researches have been carried out extensively in the past two decades, which enrich the knowledge of land system ...science. This paper describes the development of research on land use transitions in China from the perspectives of conceptual connotations, theoretical model, research methods, and research progress and prospects. With the in-depth investigation of land use transitions, the concept and connotations of land use morphology are developed and encapsulated as two kinds, i.e., dominant morphology and recessive morphology. The dominant morphology refers to the land use structure of a certain region over a certain period of time, with features such as the quantity and spatial pattern of land use types. While the recessive morphology includes the land use features in the aspects of quality, property rights, management mode, input, output and function. Accordingly, the concept of land use transition is further developed, and the theoretical model of regional land use transitions is established. Thereafter, three innovative integrated approaches to study land use transitions are put forward, i.e., multidisciplinary research framework for recessive land use transition, transect and horizontal comparison. To date, there have been 62 Ph.D. and 166 M.S. dissertations on the topic of “land use transition” in China. During 2002–2019, the National Natural Science Foundation of China has funded 48 research programs on the theme of “land use transition”. As such, the Chinese scholars have adapted the concept derived from western literature to the situations and experiences in China.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The study of land use transition has generally become an important breakthrough point to deeply understand the human-land interaction and reveal major socio-economic development issues and related ...environmental effects. Attempting to provide scientific support for sustainable land use and environmental management, this review systematically analyzes the overall picture, development trends, key fields and hot topics of land use transition research in the past two decades from a comprehensive perspective, which incorporates two complementary parts including the systematic quantitative literature review (based on CiteSpace) and the traditional literature review. The results reveal that: a. current research presents three characteristics, i.e., focusing on complex social issues, driven by realistic demand, and research branches becoming clearer and more systematic; b. there are four key fields and hot topics in land use transition research, i.e., i. theories and hypothesis of land use transition; ii. measuring land use transition; iii. the impacts of land use transition on “social-economic-ecological” system; iv. drivers and regulation of land use transition. However, challenges remain, current land use transition research is still to some extent fragmented, and it should be enriched by integrating with land system science. The dominant morphology biased should be redressed by underlining the recessive morphology transition process. Meanwhile, new techniques and methods are necessary to observe, track, monitor and model the recessive attributes. Finally, distant drivers of land use transition should not be ignored in this rapidly globalizing world.
Recent works have proposed that chromium (Cr) isotopes could be fractionated during peridotite partial melting and basaltic magma crystallization. However, until now, inter-mineral Cr isotope ...fractionation behavior for major mantle minerals has been poorly constrained. To investigate the mechanism and magnitude of equilibrium inter-mineral Cr isotope fractionation and to explore its implications for planetary mantle and crust lithology evolutions, we performed a systematic study of equilibrium Cr isotope fractionation between major mantle minerals by coupling theoretical ionic modeling with laboratory isotope analyses of natural samples and Cr valence determinations by X-ray absorption near edge spectroscopy (XANES). The ionic model considers both charges and coordination environments of Cr species in mantle minerals, which have proven to be critical factors affecting inter-mineral isotope fractionation. The ionic modeling results predict a general order of spinel (Spl) > pyroxene (Py) ≥ olivine (Ol) in 53Cr/52Cr. Systematic Cr isotope analyses of coexisting mantle minerals of seventeen peridotite xenoliths from Beiyan in the North China craton were performed. Chromium isotope results for different mineral pairs of lherzolites (e.g., Δ53CrSpl–Ol of 0.11‰ to 0.16‰, Δ53CrSpl–Py of 0.04‰ to 0.11‰ and Δ53CrPy–Ol of 0.05‰ to 0.10‰ at 870 °C to 970 °C), document measurable and systematic inter-mineral Cr isotope fractionation, in excellent agreement with the modeling results predicted with XANES-determined Cr2+/ΣCr values of the mineral separates. This fractionation order could essentially account for Cr isotope behaviors during partial melting and magmatic crystallization observed in terrestrial peridotites and lunar basalts.
In contrast, we found that metasomatisms could influence Cr isotope compositions of minerals from Beiyan metasomatized clinopyroxene- (Cpx-) rich lherzolites and wehrlites by means of mineral–melt interaction and/or kinetic diffusion, leading to disequilibrium inter-mineral Cr isotope fractionation.
•A systematic study of inter-mineral Cr isotope fractionations in peridotites.•Utilizing analyses of natural samples and the ionic model prediction.•A general order of spinel > pyroxene ≥ olivine in 53Cr/52Cr is obtained.•The order could account for Cr isotope behaviors during melting and crystallization.•Metasomatism influences Cr isotope of minerals by interaction and kinetics diffusion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The sparse recovery (SR) space-time adaptive processing (STAP) method has excellent clutter suppression performance under the condition of limited observation samples. However, when the cluttering is ...nonlinear in a spatial-Doppler profile, it will cause an off-grid effect and reduce the sparse recovery performance. A meshless search using a meta-heuristic algorithm (MH) can completely eliminate the off-grid effect in theory. Therefore, genetic algorithm (GA), differential evolution (DE), particle swarm optimization (PSO), and grey wolf optimization (GWO) methods are applied to SR-STAP for selecting exact clutter atoms in this paper. The simulation results show that MH-STAP can estimate the clutter subspace more accurately than the traditional algorithm; PSO-STAP and GWO-STAP showed better clutter suppression performance in four MH-STAP methods. To search for more accurate clutter atoms, PSO and GWO are combined to improve the method's capacity for global optimization. Meanwhile, the fitness function is improved by using prior knowledge of the clutter distribution. The simulation results show that the improved PSO-GWO-STAP algorithm provides excellent clutter suppression performance, which solves the off-grid problem better than does single MH-STAP.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Disulfide constrained peptides (DCPs) show great potential as templates for drug discovery. They are characterized by conserved cysteine residues that form intramolecular disulfide bonds. Taking ...advantage of phage display technology, we designed and generated twenty-six DCP phage libraries with enriched molecular diversity to enable the discovery of ligands against disease-causing proteins of interest. The libraries were designed based on five DCP scaffolds, namely Momordica charantia 1 (Mch1), gurmarin, Asteropsin-A, antimicrobial peptide-1 (AMP-1), and potato carboxypeptidase inhibitor (CPI). We also report optimized workflows for screening and producing synthetic and recombinant DCPs. Examples of novel DCP binders identified against various protein targets are presented, including human IgG Fc, serum albumin, vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor (PDGF). We identified DCPs against human IgG Fc and serum albumin with sub-micromolar affinity from primary panning campaigns, providing alternative tools for potential half-life extension of peptides and small protein therapeutics. Overall, the molecular diversity of the DCP scaffolds included in the designed libraries, coupled with their distinct biochemical and biophysical properties, enables efficient and robust identification of de novo binders to drug targets of therapeutic relevance.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Volatile organic compounds (VOCs) management has been recently given a high priority in China to mitigate ozone (O3) air pollution. However, there is a relatively poor understanding of VOCs due to ...their complexity and fewer observations. To better understand the pollution characteristics of VOCs and their impact on O3 pollution, two-year continuous measurements were conducted at four representative sites in Ji'nan, eastern China. These four sites cover urban, background, and industrial areas (within a petroleum refinery). Ambient VOCs showed higher concentrations at industrial site than at urban and background sites, owing to intensive emissions from petrochemical industry. The VOCs compositions present spatial heterogeneity with alkenes dominated in total reactivity at urban and background sites, while alkenes and aromatics together dominated at industrial site. The VOCs emission profile from petrochemical industry was calculated based on observational data, which revealed a huge impact on light alkanes (C2–C5), light alkenes (ethene), and aromatics (toluene and m/p-xylene). The positive matrix factorization (PMF) model analysis further refined the impact of different petrochemical industrial processes. Alkanes and alkenes dominated the emissions during refining process, while aromatics dominated during solvent usage process. Analysis by an observation-based model indicated stronger in-situ O3 production and higher sensitivity to nitrogen oxides at industrial site compared to urban and background sites. The reduction of VOCs emissions from petrochemical industry would significantly reduce the O3 concentrations. The analyses underline the significant impact of petrochemical industry on VOCs and O3 pollution, and provide important reference for the formulation of refined and effective control strategies.
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•Two-year online measurements of VOCs were conducted at four sites in a Chinese city.•Petrochemical industry led to higher VOC level and larger aromatic contribution.•Strong O3 production and high sensitivity to NOx were determined at industrial site.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Different with the traditional method that structural seismic responses were directly compared, in this study, through seismic fragility analysis, we investigated the aftershock influence on seismic ...performance of reticulated domes from probability perspective.•Existing researches have proved that the dominant vibration mode-based ground motion intensity measure Sa,dom(Td 1, Td 2, …, Td i, …, Td N, ξ) was proposed as the most appropriate ground motion intensity measure for reticulated domes. However, it is not suitable for seismic study subjected to aftershocks, because the dominant vibration modes of damaged reticulated domes under main shocks would change. Therefore, in this study, we proposed the appropriate aftershock ground motion intensity measure for reticulated domes.•Based on the above ground motion intensity measure, we performed the fragility analysis of intact reticulated domes under main shock-aftershock sequences, and obtained the main shock-aftershock sequence fragility curves of structures for seismic design of reticulated domes considering multiple earthquake effects before earthquakes.•Different with the traditional seismic fragility analysis, we also performed the fragility analysis of damaged reticulated domes with different damage levels caused, which lead seismic fragility analysis not limited to intact structures and expanded the application scope of seismic fragility analysis.
In this paper, single-layer and double-layer reticulated domes were taken as two typical research objects. Through the dynamic time history analysis of reticulated domes in full process domain, log-linear regression was performed with a large number of example results to compare the degrees of correlation and efficiency about 11 common ground motion intensity measures, and PGA was selected as the most applicable one for fragility analysis of reticulated domes with aftershock influence. Then, considering that main shock usually caused structural damage, with incremental dynamic analysis method, fragility analysis of reticulated domes under multiple earthquakes was conducted from two aspects as follows. One part was main shock-aftershock sequence fragility analysis of intact structures. The other part was aftershock fragility analysis of damaged structures with four different damage levels caused by main shocks. Based on the fragility curves, the aftershock influence on fragility of reticulated domes and the aftershock collapse probability of damaged reticulated domes with four different damage levels caused by main shocks were investigated. It was found that when the damage level reached severe damage under main shocks, the aftershock collapse probability of reticulated domes would increase significantly. The results expanded the application scope of traditional fragility analysis in seismic engineering and realized the prediction and evaluation of seismic performance of reticulated domes under aftershocks.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Understanding the driving forces of environmental consequences is pivotal for agricultural sustainability.•An integrated approach hybridized by econometric modeling and machine learning was ...used.•Income and geographical proximity factor determine a large share of variation both fertilizer use and water quality.•Non-linear associations discovered will be conducive to policy improvement.
Farming in sustainable ways is rapidly gaining importance, which necessitates a quantitative understanding of the major determinants of agricultural environmental consequences. The main objective of this paper is to investigate the environmental effects and their drivers of agricultural production through the lens of fertilizer application and water quality. An integration of the econometric modeling and machine learning methodologies (multiple regression model and boosted regression trees method) was employed to dissect the relative importance and the non-linearity of each variable. The results showed that (1) Household income level is a primary contributing factor to both fertilizers use and water quality, demonstrating an increasing marginal effect. (2) Proximity factor-distance from provincial capital city positively correlated with these two terms. (3) Water quality is more sensitive to natural conditions, such as precipitation and elevation, which also considerably affect fertilizer use. (4) Agricultural mechanization level is positively related to fertilizer use despite their non-linear effects. In summary, capital, technology, and labor input are the major socio-economic determinants of the environmental consequences, which were also largely associated with regional natural conditions. These findings provide quantitative insights that can be used to improve the agro-environment and achieve sustainable agricultural growth.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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