In Alexandrov's work 4,5 it has been shown that the extended partition function exp(Fo,ext+Fc) introduced by Buryak in 14,15 is a tau-function of the KP hierarchy. In this work, we compute the ...affine coordinates of this tau-function on the Sato Grassmannian, and rewrite the Virasoro constraints as recursions for the affine coordinates in the fermionic picture. As applications we derive some formulas for the extended partition function and the connected n-point functions using methods developed by Zhou in 48 based on the boson-fermion correspondence.
Process optimization often has two or more objectives which are conflicting. For such situations, multiobjective optimization (MOO) provides many optimal solutions, which are equally good from the ...perspective of the given objectives. These solutions, known as Pareto-optimal front and as nondominated solutions, provide deeper insights into the trade-off among the objectives and many choices for implementation. In the past 20 years, researchers have applied MOO to numerous applications in chemical engineering. However, selection of an optimal solution from the set of nondominated solutions has not received much attention in the chemical engineering literature. In the present study, 10 methods for selecting an optimal solution from the Pareto-optimal front are carefully chosen and implemented in an MS Excel-based program. Then, they are applied to the selection of an optimal solution in many benchmark or mathematical problems and chemical engineering applications, and their effectiveness and similarities are analyzed. Results of analysis indicate that, among the 10 methods studied, technique for order of preference by similarity to ideal solution, gray relational analysis, and simple additive weighting are better for choosing one of the Pareto-optimal solutions.
As a new and popular material, single‐atom catalysts (SACs) exhibit excellent activity, selectivity, and stability for numerous important reactions, and show great potential in heterogeneous ...catalysis due to their high atom utilization efficiency and the controllable characteristics of the active sites. The composition and coordination would determine the geometric and electronic structures of SACs, and thus greatly influence the catalytic performance. Based on atom economy, rational design and controllable synthesis of SACs have become central tasks in the fields of low‐cost and green catalysis. Herein, an introduction to the recent progress in the precise synthesis of SACs including the regulation of the coordination structure and the choice of different systems is presented. Thereafter, the potentials of SACs in different applications are comprehensively summarized and discussed. Furthermore, a detailed discussion of the recent developments regarding the large‐scale preparation of SACs is provided, including the major issues and prospects for industrialization. Finally, the main challenges and opportunities of rapid large‐scale industrialization of SACs are briefly discussed.
The development and exploration of highly efficient single‐atom catalysts (SACs) is of enormous significance for achieving industrialization. The advanced progress of precise synthesis and practical application of SACs is summarized. Thereafter, the main challenges and future opportunities of large‐scale synthesis of SACs are discussed.
This article evaluates how China's foreign aid affects human rights in Africa. Using the fixed effects model to analyze a data set on China's aid from 2000 to 2013, this research finds: (1) in the ...African recipient states China's aid exhibits virtually no negative and statistically significant impact on physical integrity rights, (2) it does not discourage conditional aid inflows, and (3) it fails to offset the positive human rights effects of conditional aid. The findings are robust to various econometric estimators, alternative model specifications, and multiple human rights measures. Overall, China's aid shows no sign of systemically weakening basic human rights protection in Africa.
•A comprehensive method was used to evaluate the regional water environment carrying capacity (WECC).•The improvement path of WECC is discussed from two aspects of index level and coupling ...coordination degree.•Saving water resources is an efficient and easy-to-implement plan for WECC improvement.•Coupling coordination among subsystems is a necessary condition for improving WECC.
A key influence factor of sustainable regional development is the water environment carrying capacity (WECC), which is a prerequisite for ecological security and harmonious regional development. Utilizing the benefits of the dynamic analysis of system dynamics (SD) and the Driver-Pressure-State-Impact-Response (DPSIR) framework system, we constructed a water environment carrying capacity-system dynamics (WECC-SD) model and evaluation index system for Shanxi Province. Five possible future development schemes were designed to predict the changes in WECC from 2020 to 2030. Further, we analyzed the system coordination with the coupling coordination degree model. The results manifest that the comprehensive ranking of WECC under different schemes is: comprehensive scheme > water environment protection scheme > water conservation scheme > status quo scheme > economic development scheme. The economic development scheme performs the worst in WECC and coupling coordination performance, the water conservation and water environment protection schemes can both improve WECC to varying degrees but promote coordinated system development to a very limited extent, the comprehensive scheme can significantly improve WECC and system coordination and is the best strategy to realize the coordinated and steady development of regional economic activities and the water environment. In future development, economic development should be moderated on the premise that the quality of the water environment will gradually enhance and the consumption of water resources will continue to decline, so that a benign relationship between population – economy – water resources – water environment can be created and a steady increase in the level of coordinated regional development can be promoted. The study reveals complex impact relationships within the WECC system and informs the development of future regional planning and environmental policy.
•The expansion of construction land had a negative impact on regional carbon storage.•Rational growth of regional construction land, enhancement of carbon sink capacity.•Assessment of the potential ...impact of construction land growth on carbon storage.•Ecological vulnerability assessment, a potential impact evaluation.
The extension of urban development can encroach onto ecologically important land, such as forests and farmland, and have a significant impact on regional ecosystem carbon storage. Although there has been extensive research on the carbon storage response to land use changes, limited exploration has been conducted on the changes in ecosystem carbon storage resulting from the expansion of construction land.. In the current research, we analyzed the characteristics involved in the growth related to built-up space in the Changzhutan metropolitan area from 1990 to 2020. Using the InVEST model, we evaluated the resulting effects on ecological carbon sequestration, and using the PLUS model, we simulated the effects of building land expansion under four scenarios: natural development, farmland protection, ecological protection, and comprehensive development. Additionally, our aim was to quantify the possible implications of the development of built-up areas on regional carbon storage. (1) The Changzhutan metropolitan area expanded its construction land by 721.58 km2 from 1990 to 2020, with the expansion mainly concentrated in the urban fringe areas, and the land type mainly changed from forests and farmland to construction land. (2) The ecosystem carbon sequestration in the Changsha-Zhuzhou-Xiangtan metropolitan area decreased by 22.66 × 106 t from 1990 to 2020, with the most significant decrease occurring from 2005 to 2010 when the expansion of construction land was 284.43 km2. (3)By 2030, the Changzhutan metropolitan area is projected to expand its construction land by 312.05 km2, 175.65 km2, 68.21 km2, and 68.90 km2 under the scenarios of natural development, farmland protection, ecological protection, and comprehensive development, respectively. Land use change in each scenario is expected to cause carbon storage losses of 10.01 × 106 t, 11.01 × 106 t, 2.07 × 106 t, and 1.95 × 106t, compared to 2020. (4) Over the investigation time span, expansion of construction ground in metropolitan Changzhutan had a negative impact on regional carbon storage, reaching a stable state from 2005 to 2020, and the effect pertaining to growth from the area of development upon the carbon accumulation of regional ecosystems under the comprehensive protection scenario in 2030 was −0.46. Considering the spatial heterogeneity analysis of regional carbon storage, this scenario would substantially upgrade the functional area surrounding the region and increase the biological system stabilization, which is conducive to achieving carbon neutrality goals.
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•NIs effectively inhibited N2O emission and AOB growth.•NIs could not inhibit AOA growth and nitrification process.•DCD and DMPP were able to inhibit the activity of comammox.•The ...efficacy of NIs was influenced by soil properties.
The use of nitrification inhibitors (NIs) with ammonium (NH4+) -based fertilizers is an efficient strategy for reducing nitrogen (N) loss by affecting ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in agricultural soils. The inhibition mechanisms of NIs on AOA and AOB are still debated, as some studies have demonstrated that NIs inhibited functionally dominant groups, while others have reported selective inhibition of AOB rather than AOA. Here, we identified the impacts of the most commonly used NIs (dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP) and nitrapyrin) on the nitrification activity, N2O emission, and abundance and metabolic activity of ammonia oxidizers (AOA, AOB, and comammox (detected only in HL)) in three paddy soils (HL, JX, and SC) with distinct properties using microcosm incubation combined with the 13CO2-DNA-stable isotope probing (SIP) technique. Most of the NIs treatments effectively inhibited the N2O emission with efficacy suppressed the metabolic activity of AOB, regardless of soil type and NI type, whereas the nitrification process and AOA activity could not be inhibited. The efficacy of NIs was also dependent on soil chemical properties, as nitrapyrin did not inhibit AOB growth at the beginning of microcosm incubation in HL, and DCD successfully inhibited the activity of both AOA and AOB in JX. In HL, DCD and DMPP effectively inhibited the activity of comammox, while nitrapyrin could not inhibit its activity. This study is the first to identify the response pattern of comammox to DCD, DMPP, and nitrapyrin in paddy soil by DNA-SIP microcosm incubation. This study also suggested that NIs might selectively inhibit AOB rather than AOA.
•Cyanobacteria serve as vital reservoir and source for antibiotic resistance genes.•Relatively high abundance of antibiotic resistance genes occurs in bloom season.•Cyanobacterial extracellular DNA ...carrying antibiotic resistance genes is persistent.•Antibiotic resistance genes are more stable in cyanobacteria at lower temperature.•Cyanobacterial blooms promote conjugative transfer of antibiotic resistance genes.
The widespread occurrence of antibiotic resistance genes (ARGs) throughout aquatic environments has raised global concerns for public health, but understanding of the emergence and propagation of ARGs in diverse environmental media remains limited. This study investigated the occurrence and spatio-temporal patterns of six classes of ARGs in cyanobacteria isolated from Taihu Lake. Tetracycline and sulfonamide resistance genes were identified as dominant ARGs. The abundance of ARGs in cyanobacteria was significantly higher in the bloom period than in the non-bloom period. The contribution and persistence of ARGs were higher in extracellular DNA (eDNA) than in intracellular DNA (iDNA) from cyanobacteria. Cyanobacteria-associated eDNA carrying ARGs was more stable at lower temperature. The relative abundances of ARGs in Microcystis and Synechococcus, the dominant genera of cyanobacterial blooms in Taihu Lake, were significantly higher than those in other cyanobacterial strains. The conjugative transfer efficiency for bacterial assimilation of ARGs in cyanobacteria was facilitated by increasing temperature and cyanobacterial cell concentration. Our results demonstrated that cyanobacteria could act as a significant reservoir and source for the acquisition and dissemination of ARGs in aquatic environments, hence the definition of negative ecological effects of cyanobacterial blooms was expanded.
Lithium-rich layered cathode Li1.2Mn0.54Ni0.13Co0.13O2 is synthesized by a co-precipitation method followed by high-temperature treatment and surface coated with different amount of amorphous FePO4. ...The microstructure and electrochemical performance of the as-prepared cathode materials are investigated systematically. It is demonstrated that the Li1.2Mn0.54Ni0.13Co0.13O2 particles are uniformly coated with amorphous FePO4. With proper amount of amorphous FePO4 coating layer, significant improvements in discharge capacity, initial Coulombic efficiency, rate capability, cycle performance, and thermal stability are achieved at room temperature. Specifically, the 3 wt.% FePO4-coated cathode exhibits the highest discharge specific capacities (271.7 mAh g−1 at C/20), improved initial Coulombic efficiency (85.1%), and best cyclability (discharge capacity of 202.6 mAh g−1 at C/2 after 100 cycles), while the 1 wt.% FePO4-coated cathode displays the best rate capability (194.3 mAh g−1 at 1 C rate and 167.9 mAh g−1 at 2 C rate). The charge–discharge curves and electrochemical impedance spectra reveal that the improved electrochemical performances are due to the suppression of both the oxygen vacancy elimination at the end of the first charge and side reactions of the cathode with the electrolyte, as well as the decrease in charge transfer polarization by the FePO4 coating layer.
► Li1.2Mn0.54Ni0.13Co0.13O2 coated with a uniform layer of FePO4 was synthesized. ► Electrochemical performance was significantly improved by FePO4 coating. ► FePO4 coating layer suppresses the side reactions with the electrolyte. ► FePO4 coating enhances kinetics of Li1.2Mn0.54Ni0.13Co0.13O2 material.
Climate variation of global monsoon (GM) precipitation involves both internal feedback and external forcing. Here, we focus on strong volcanic forcing since large eruptions are known to be a dominant ...mechanism in natural climate change. It is not known whether large volcanoes erupted at different latitudes have distinctive effects on the monsoon in the Northern Hemisphere (NH) and the Southern Hemisphere (SH). We address this issue using a 1500-year volcanic sensitivity simulation by the Community Earth System Model version 1.0 (CESM1). Volcanoes are classified into three types based on their meridional aerosol distributions: NH volcanoes, SH volcanoes and equatorial volcanoes. Using the model simulation, we discover that the GM precipitation in one hemisphere is enhanced significantly by the remote volcanic forcing occurring in the other hemisphere. This remote volcanic forcing-induced intensification is mainly through circulation change rather than moisture content change. In addition, the NH volcanic eruptions are more efficient in reducing the NH monsoon precipitation than the equatorial ones, and so do the SH eruptions in weakening the SH monsoon, because the equatorial eruptions, despite reducing moisture content, have weaker effects in weakening the off-equatorial monsoon circulation than the subtropical-extratropical volcanoes do.
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