The multi-document summarization task requires the designed summarizer to generate a short text that covers the important information of original multiple documents and satisfies content diversity. ...To fulfill the dual requirements of coverage and diversity in multi-document summarization, this study introduces a novel method. Initially, a class tree is constructed through hierarchical clustering of documents. Subsequently, a sentence selection method based on class tree is proposed for generating a summary. Specifically, a top-down traversal is performed on the class tree, during which sentences are selected from each node based on their similarity to the centroid of the documents within the node and their dissimilarity to the centroid of documents not belonging to the node. Sentences selected from the root node reflect the commonality of all document, and sentences selected from the sub nodes reflect the distinct specificity of the respective subclasses. Experimental results on standard text summarization datasets DUC'2002, DUC'2003, and DUC'2004 demonstrate that the proposed method significantly outperforms the variant method that considers only commonality of all documents, achieving average improvements of up to 1.54 and 1.42 in ROUGE-1 and ROUGE-L scores, respectively. Additionally, the method demonstrates significant superiority over another variant method that considers only the specificity of subclasses, achieving average improvements of up to 2.16 and 2.01 in ROUGE-1 and ROUGE-L scores, respectively. Furthermore, extensive experiments on DUC'2004 and Multi-News datasets show that the proposed method outperforms lots of competitive supervised and unsupervised multi-document summarization methods and yields considerable results.
This paper carries out the quasi-natural experiment on China’s carbon emissions trading pilot policy to assess the impact of China’s carbon emissions trading pilot policy on the export product ...quality of enterprises in the pilot areas by using the data of listed companies and China Customs, and employing the DDD method. Meanwhile, it analyzes the heterogeneity of the impact under different ownership attributes and energy-intensive attributes of enterprises. The empirical results are as follows. First, due to the implementation of the carbon emissions trading pilot policy, the enterprises in the included industries bear the emission reduction cost. The export product quality of the enterprises in the included industries in the pilot areas is negatively affected compared with that of nonincluded enterprises in the nonpilot areas. Second, the impact of the carbon emissions trading pilot policy on the export product quality of enterprises may be heterogeneous due to the different ownership attributes of enterprises. The carbon emissions trading pilot policy significantly reduces the export product quality of non-state-owned enterprises, but has no significant effect on state-owned enterprises. Third, the impact of the carbon emissions trading pilot policy on the export product quality of enterprises is heterogeneous due to different energy-intensive attributes of enterprises. The carbon emissions trading pilot policy significantly reduces the export product quality of enterprises in energy-intensive industries, but it does not have a significant impact on enterprises in non-energy-intensive industries.
Full text
Available for:
DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Rechargeable lithium-ion batteries (LIBs) are important electrochemical energy storage devices for consumer electronics and emerging electrical/hybrid vehicles. However, one of the formidable ...challenges is to develop ultrafast charging LIBs with the rate capability at least one order of magnitude (>10 C) higher than that of the currently commercialized LIBs. This tutorial review presents the state-of-the-art developments in ultrafast charging LIBs by the rational design of materials. First of all, fundamental electrochemistry and related ionic/electronic conduction theories identify that the rate capability of LIBs is kinetically limited by the sluggish solid-state diffusion process in electrode materials. Then, several aspects of the intrinsic materials, materials engineering and processing, and electrode materials architecture design towards maximizing both ionic and electronic conductivity in the electrode with a short diffusion length are deliberated. Finally, the future trends and perspectives for the ultrafast rechargeable LIBs are discussed. Continuous rapid progress in this area is essential and urgent to endow LIBs with ultrafast charging capability to meet huge demands in the near future.
This tutorial review provides fundamental electrochemistry and presents state-of-the-art developments in ultrafast charging lithium-ion batteries by the rational design of materials.
Functional mesoporous materials have gained tremendous attention due to their distinctive properties and potential applications. In recent decades, the self-assembly of micelles and framework ...precursors into mesostructures on the liquid–solid, liquid–liquid, and gas–liquid interface has been explored in the construction of functional mesoporous materials with diverse compositions, morphologies, mesostructures, and pore sizes. Compared with the one-phase solution synthetic approach, the introduction of a two-phase interface in the synthetic system changes self-assembly behaviors between micelles and framework species, leading to the possibility for the on-demand fabrication of unique mesoporous architectures. In addition, controlling the interfacial tension is critical to manipulate the self-assembly process for precise synthesis. In particular, recent breakthroughs based on the concept of the “monomicelles” assembly mechanism are very promising and interesting for the synthesis of functional mesoporous materials with the precise control. In this review, we highlight the synthetic strategies, principles, and interface engineering at the macroscale, microscale, and nanoscale for oriented interfacial assembly of functional mesoporous materials over the past 10 years. The potential applications in various fields, including adsorption, separation, sensors, catalysis, energy storage, solar cells, and biomedicine, are discussed. Finally, we also propose the remaining challenges, possible directions, and opportunities in this field for the future outlook.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Soil microbial communities play an essential role in driving multiple functions (i.e., multifunctionality) that are central to the global biogeochemical cycles. Long-term fertilization has been ...reported to reduce the soil microbial diversity, however, the impact of fertilization on multifunctionality and its relationship with soil microbial diversity remains poorly understood. We used amplicon sequencing and high-throughput quantitative-PCR array to characterize the microbial community compositions and 70 functional genes in a long-term experimental field station with multiple inorganic and organic fertilization treatments. Compared with inorganic fertilization, the application of organic fertilizer improved the soil multifunctionality, which positively correlated with the both bacterial and fungal diversity. Random Forest regression analysis indicated that rare microbial taxa (e.g. Cyanobacteria and Glomeromycota) rather than the dominant taxa (e.g. Proteobacteria and Ascomycota) were the major drivers of multifunctionality, suggesting that rare taxa had an over-proportional role in biological processes. Therefore, preserving the diversity of soil microbial communities especially the rare microbial taxa could be crucial to the sustainable provision of ecosystem functions in the future.
Display omitted
•Inorganic fertilization decreased soil multifunctionality.•Organic fertilization increased microbial diversity and multifunctionality.•Rare microbial taxa had an over-proportional role in multifunctionality.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With the aim to solve the serious problem of white plastic pollution, we report herein a low-cost process to quantitatively convert polyethylene terephthalate (PET) into p-xylene (PX) and ethylene ...glycol (EG) over modified Cu/SiO
catalyst using methanol as both solvent and hydrogen donor. Kinetic and in-situ Fourier-transform infrared spectroscopy (FTIR) studies demonstrate that the degradation of PET into PX involves tandem PET methanolysis and dimethyl terephthalate (DMT) selective hydro-deoxygenation (HDO) steps with the in-situ produced H
from methanol decomposition at 210 °C. The overall high activities are attributed to the high Cu
/Cu
ratio derived from the dense and granular copper silicate precursor, as formed by the induction of proper NaCl addition during the hydrothermal synthesis. This hydrogen-free one-pot approach allows to directly produce gasoline fuels and antifreeze components from waste poly-ester plastic, providing a feasible solution to the plastic problem in islands.
A highly active catalyst, hierarchical nano-sized Ni/HBEA, is developed for stearic acid and palm oil hydrodeoxygenation (HDO) in dodecane. The TPAOH/NaOH treated hierarchical HBEA sample (crystal ...size: 15-20 nm) affords more homogeneously dispersed open inter-mesopores (main pore diameter: 25 nm) viacontrollable base leaching, as evidenced by various microscopy and spectroscopy techniques. By the formation of an aluminum complex on the crystal surface, TPA super(+) prevents the specific external structure from deep corrosion. After loading Ni nanoclusters, the modified Ni/HBEA was supported with more loadable and dispersive Ni nanoclusters (d= 7.7 plus or minus 1.5 nm) in the newly formed inter-crystalline mesopores, which provide higher accessibility towards heavy molecules, as well as restrict the Ni particle growth. This novel catalyst shows a significantly high initial rate of 67 mmol g super(-1) h super(-1) (equivalent to 19 g g super(-1) h super(-1)) for producing 85% n-C sub(17)/C sub(18) and 11% iso-C sub(17)/C sub(18) alkanes by stearic acid conversion at 260 degree C and 4 MPa H sub(2), and the efficiency of this method is far beyond the current techniques using sulfur-metal and reduced-metal catalysts. The HDO route follows the major pathway of sequential hydrogenation and dehydration steps, affording a highly atom-economical process and a suitable diesel oil ingredient (with certain branched alkanes). In addition, high activities are achieved with the improved catalyst after treatment with high concentration stearic acid in dodecane (up to 0.5 g mL super(-1)), and the catalyst remains highly active and stable in the four recycling runs of palm oil HDO.
Summary
Bacterial resistance to antibiotics and heavy metals are frequently linked, suggesting that exposure to heavy metals might select for bacterial assemblages conferring resistance to ...antibiotics. However, there is a lack of clear evidence for the heavy metal‐induced changes of antibiotic resistance in a long‐term basis. Here, we used high‐capacity quantitative PCR array to investigate the responses of a broad spectrum of antibiotic resistance genes (ARGs) to 4–5 year copper contamination (0–800 mg kg−1) in two contrasting agricultural soils. In total, 157 and 149 unique ARGs were detected in the red and fluvo‐aquic soil, respectively, with multidrug and β‐lactam as the most dominant ARG types. The highest diversity and abundance of ARGs were observed in medium copper concentrations (100–200 mg kg−1) of the red soil and in high copper concentrations (400–800 mg kg−1) of the fluvo‐aquic soil. The abundances of total ARGs and several ARG types had significantly positive correlations with mobile genetic elements (MGEs), suggesting mobility potential of ARGs in copper‐contaminated soils. Network analysis revealed significant co‐occurrence patterns between ARGs and microbial taxa, indicating strong associations between ARGs and bacterial communities. Structural equation models showed that the significant impacts of copper contamination on ARG patterns were mainly driven by changes in bacterial community compositions and MGEs. Our results provide field‐based evidence that long‐term Cu contamination significantly changed the diversity, abundance and mobility potential of environmental antibiotic resistance, and caution the un‐perceived risk of the ARG dissemination in heavy metal polluted environments.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Conspectus Mesoporous materials with various structures have attracted considerable attention due to their distinctive properties such as large pore sizes, high surface areas, tunable pore ...structures, and controllable framework compositions. Among them, spherical mesoporous materials (SMMs) are of great interest owing to the unique spherical shape, which show the closed packing nature and lowest surface energy. The open mesopores and short channels of SMMs not only increase the density of high accessible active sites but also facilitate the mass diffusion with short length. These characteristics are particularly useful for applications in catalysis, adsorption, energy storage and conversion, biomedicine, and so on. In addition, the creation of a spherical shape is conformable to the law of natural selection because objects in nature tend to minimize energy, while the sphere is one of the most perfect matter structures. Therefore, the design and synthesis of SMMs are very important from both fundamental and technological viewpoints. Compared to the simple single-level, SMMs with more complex multilevel structures inevitably bring unusual mechanical, electrical, and optical properties, which are highly desired for practical applications. For example, the construction of core–shell structured SMMs has inspired great attention as they can combine multiple components into one functional unit, exhibiting ameliorated or new physicochemical properties, which cannot be obtained from the isolated one. The presence of a hollow cavity in the yolk–shell structure allows sufficient exposure of the core while maintaining the protective ability of the shell, which is conducive to retaining the distance-dependent properties of the core. Multishelled hollow structures consisting of two or more mesoporous shells are expected to show superior activities in various applications compared to their bulk counterparts because more active interfaces and unique compartmentation environments can be provided. Therefore, SMMs from single to multilevel structure represent a class of advanced nanostructured materials with unique structures and fascinating properties. In this Account, we highlight the progresses on the synthesis and applications of SMMs from single to multilevel architectures. The synthetic strategies have been summarized and categorized into (i) the modified Stöber method, (ii) the hydrothermal strategy, (iii) the biphase stratification approach, (iv) the nanoemulsion assembly method, (v) the evaporation induced aggregating assembly (EIAA) method, and (vi) the confined self-assembly strategy. Special emphasis is placed on the synthetic principles and underlying mechanisms for precise control of SMMs over the particle sizes, pore sizes, pore structures and functionalities as well as different levels of architectures. Moreover, the implementation performances in catalysis, drug delivery, and energy related fields have been highlighted. Finally, the opportunities and challenges for the future development of SMMs in terms of synthesis and applications are proposed.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
This paper explores the effect of the Double-pillar regulation on promoting enterprise innovation and its influencing mechanism. Based on the panel data of A-share listed nonfinancial enterprises in ...China from 2010 to 2019, this paper empirically examines the driving effect of the Double-pillar regulation on enterprise innovation and its influencing mechanism. The empirical results demonstrate that the Double-pillar regulation can promote enterprise innovation, and there is significant regional heterogeneity. The Double-pillar regulation has a stronger driving effect on the innovation of state-owned enterprises. The Double-pillar regulation can effectively reduce the financialization of enterprises, thus boosting enterprise innovation. The degree of financing constraint and the improvement of enterprise risk-taking level will enhance the driving effect of the double-pillar regulation on enterprise innovation. The research of this paper promotes the understanding of the effect, mechanism, and regional differences of enterprise innovation under the Double-pillar regulation. Meanwhile, it also examines the necessity of building the Double-pillar regulation framework.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
