Single‐atom catalysts have emerged as an efficient oxidant activator for eliminating organic pollutants in Fenton‐like systems. However, the complex preparation, single active site, lack of ...understanding of the fundamental mechanism, and harsh pH conditions currently limit their practical applications. In this work, single‐atom iron anchored nitrogen‐rich g‐C3N4 nanotubes (FeCNs) are designed and synthesized by a facile approach, and eco‐friendly peracetic acid (PAA) is selected as the oxidant for Fenton‐like reactions. The constructed heterogenous system achieves an enhanced degradation of various organic contaminants over a wide pH range of 3.0–9.0, exhibiting an ultrahigh and stable catalytic activity, outperforming equivalent quantities of pristine g‐C3N4 by 75 times. The 18O isotope‐labeling technique, probe method, and theoretical calculations demonstrate that the efficient catalytic activity relies on the high‐valency iron‐oxo species coupled with organic radicals generated by PAA. An increase in electron transport from the contaminant to the formed “metastable PAA/FeCN catalyst surface complex” is detected. A double driving mechanism for the tubular g‐C3N4 regulated by a single Fe site and PAA activation is proposed. This work opens an avenue for developing novel catalysts with the coexistence of multiple active units and providing opportunities for significantly improving catalytic efficiency.
Atomically dispersing Fe(III) sites into fine‐tuned nitrogen‐rich graphitic carbon nitride nanotubes are designed for peracetic acid activation and further for Fenton‐like reactions. This work opens a new avenue to develop heterogenous catalytic systems with higher reactivity and better durability using a double engine mechanism.
Energy discourse research profoundly influences energy policy, public opinion, and sustainable development. Despite its complexity, this study, using CiteSpace, analyzes the recent progress and ...hotspots in the field. The results indicate an increasing number of publications, regional collaborations, and interdisciplinary integrations; the field integrates different disciplines and covers a variety of topics. In addition, themes such as energy transition, technological innovation, and climate change are likely to be future trends in energy discourse research. This study contributes to the field by providing a dynamic macro-perspective on energy discourse research, which will help to provide a comprehensive and systematic research reference for scholars, policymakers, and practitioners in the field of energy discourse and to promote the academic development and practical application of the field.
•Growing trend in energy discourse publications shows increased interest.•Main focus: climate change, renewable energy, energy transition, security.•Framework links current research with future trends for scholars, policymakers.•Impact of discourse on shaping energy policies, technology, and public opinion.
•Fe and O codopants substantially accelerated the electron transfer of g-C3N4 for PMS activation.•Efficient BPA removal was achieved at high salinity and within wider pH ranges.•High-valent iron-oxo ...species and singlet oxygen were identified as two main reactive species.•Nonradical pathways were elucidated based on experimental and theoretical analyses.
Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) for wastewater treatment have recently attracted widespread interests. However, the degradation of organic pollutants via traditional radical-dominated pathway is severely limited by the side reactions between radicals and the co-existing inorganic anions, especially under high salinity conditions. Herein, an efficient Fe/O co-doped g-C3N4nanosheet catalyst was synthesized to dominantly activate PMS through a dual non-radical pathway with the singlet oxygen and high-valent iron-oxo species (Fe(V)=O). The rapid degradation of model pollutant bisphenol A (BPA) was achieved by dosing PMS (1 mM), catalyst (0.1 g/L) in a simulated high-salt wastewater (≥200 mM) of the developed Fe/O-doped g-C3N4+PMS system with a reaction rate constant of 1204-fold higher than that in g-C3N4+PMS system. The O and Fe co-dopants could reconfigurate the electronic structure of pristine g-C3N4 to produce more non-radical active species. The formed Fe(V)=O played a main role in the BPA degradation by promoting electron transfer from BPA molecule to the “metastable PMS/catalyst complex”, which was verified by electrochemical tests and density functional theory calculations. The auxiliary transient productions of ·OH+SO4·– species were also favorable for the pollutant degradation. Excellent reusability in a wide pH range confirmed the practical application prospects of the Fe/O-doped g-C3N4+PMS system. The successive addition of PMS with a low dosage into the system rich in pollutants was confirmed to favor the PMS utilization. Our work unveils the potential applications of a non-radical dominated process for the decontamination of organic pollutants in saline water.
Photosynthesis of hydrogen peroxide (H2O2) by selective oxygen reduction is a green and cost-effective alternative to the energy-intensive anthraquinone process. Although inexpensive polymeric ...graphitic carbon nitride (g-C3N4) exhibits the ability to produce H2O2, its disordered and amorphous structure leads to a high recombination rate of photogenerated carriers and hinders charge transfer between layers. Herein, we predict that stacked polymeric g-C3N4 with ion intercalation (K+ and I–) can improve carrier separation and transfer by multiscale computational simulations. The electronic structures of g-C3N4 were tailored and modified by intercalating K+ and I– into the layer-by-layer structures. Guided by the computational predictions, we achieved efficient solar-driven H2O2 production by employing this facile and ion-intercalated crystalline g-C3N4. An H2O2 production rate of 13.1 mM g−1 h−1 and an apparent quantum yield of 23.6% at 400 nm were obtained. The synergistic effects of crystallinity regulation and dual interstitial doping engineering triggered the formation of new light absorption centers, the establishment of rapid charge diffusion channels, and the enhancement of two-electron oxygen reduction characteristics. This work sheds light on the dual tuning of crystallinity and electronic structure and broadens the design principles of organic-conjugated polymer photocatalysts for environmental remediation and energy conservation.
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► The design concepts for chiral N-heterocyclic carbenes (NHC) ligands have been demonstrated proof-of-concept asymmetric catalysis. ► The easy introduction of chiral elements into ...NHCs and their facile preparations have made chiral NHCs as the promising alternative ligands to the more commonly used phosphines and phosphites for various asymmetric catalytic reactions. More importantly, chiral NHC–metal complexes also presented special catalytic properties in asymmetric catalyses under the atmosphere of oxygen and moisture such as asymmetric oxidations. ► Novel asymmetric synthetic methodologies achieved by NHC–metal complexes were disclosed, and asymmetric catalytic activity of NHC–metal complexes in asymmetric catalysis was discussed. ► The NHC–metal-based catalytic mechanisms were presented.
The strong σ-donor but poor π-acceptor abilities of N-heterocyclic carbenes (NHCs) result in chemical stability and coordination versatility, thus allowing them to coordinate with many metals ranging from alkaline-earth metals to rare-earth metals. Moreover, the easy introduction of chiral elements into NHCs and the facile preparation of their precursors have made chiral NHCs promising chiral ligands in metal-based asymmetric catalysis. Therefore, strategies for the design of efficient NHC–metal catalysts and novel asymmetric synthetic methodologies have dramatically increased over the past 10 years. Herein, the growing field of chiral NHC–metal-based asymmetric catalysis is comprehensively described.
Owing to the rising concerns about environmental degradation worldwide, firms in several developed and developing countries are pursuing carbon emission reduction targets. In addition, in recent ...years, there is evidence of a shift in consumer preferences in favour of low-carbon products. Using a theoretical model, where the shift in consumer preferences is explicitly incorporated, we evaluate the impact of carbon emission reduction cost-sharing on supply chain profit. In our model, consumers are willing to pay a higher price for low-carbon products and hence the retailer considers sharing the cost of carbon emission reduction with the manufacturer. Our model also includes a carbon trading mechanism. We identify a range of carbon emission reduction cost-sharing such that both supply chain enterprises are better-off. We find that, while achieving the aim of carbon emission reduction, consumer preference for low-carbon products can benefit both supply chain enterprises. Numerical simulations show that carbon emission reduction cost-sharing increases the retailer’s order quantity as well as the profit and hence there is an incentive for the two supply chain enterprises to cooperate.
With the operation of long transmission lines, unknown severe vibration and noise in transformers have sometimes been observed at the Shanghe substation and at the Ling'ao nuclear power plant in ...China. This paper gives a comparison of magnetic-storm recordings and measured transformer neutral current data and confirms that the disturbances were caused by geomagnetically induced currents (GICs). On November 7 and 9, 2004, the maximum GIC at the Ling'ao nuclear power plant was 47.2 A and 75.5 A, respectively, which are both larger than the neutral DC current caused by the HVDC monopole operation. The analysis of GIC data indicates that the GIC level is mainly determined by the geomagnetic-field variation rate, but the earth conductivity and power grid parameters are also important factors affecting GIC values. The data show that the GIC level is higher at the Ling'ao nuclear power plant than at the Shanghe substation. The reason is considered to be related to the grid structure and to the coast effect. Furthermore, because of smaller resistances, longer transmission lines, a larger scale, and the adoption of single-phase transformers, the influences of GIC on the ultra-high voltage power grid being constructed in China need to be studied more urgently.
The common place of cognitive understanding of music of the past twentieth century as a holistic musical and artistic system was not so much the birth of writing techniques, but their mixing, ...interaction, obvious synthesis, perceived integrally and organically, but very difficult to find in analysis. In the twentieth century, a change in the creative process led to the rebirth of a traditional musical form as a structure and the birth of a new type of musical composition. Taking into account the fact that the term “musical form” does not embrace all the facets of the holistic meaning of music that exist in contemporary composers' creativity, this article introduces its homonym - “musical composition”. Thus, we affirm the right of the term “composition” to act as a musical universal for its description as a demonstrator of the artistic consciousness of the composer and, accordingly, the category of comprehending the spiritual content of a musical work. By composition we will understand the structural principles of organizing a musical work as an artistic whole in the unity of musical time and space. We are talking about the stable qualities of the procedural formation of music, its architectonics (Space = architectonics) and the mobile properties of musical development (Time = intonational dramaturgy). The analytical musicology of the twentieth century has developed the criteria necessary to form the basis of the typology of musical forms of classic-romantic music. A large treasure was introduced by Russian and Ukrainian musicologists: B. Asafiev, V. Bobrovsky, V. Medushevsky, V. Kholopova, Y. Kholopov, T. Kureregian, V. Zaderatsky, etc. On the interaction of functional and historical-genre approaches, a cognitive method of analyzing contemporary composition in Chinese music of the twentieth century is built, aimed at comprehending national specificity as a culture of assimilated musical thinking. The article gave a number of examples on the “13 Preludes and Fugues” polyphonic cycle by Chen Mingzhi, a kind of Chinese “Ludus tonalis”. The analysis carried out in this article showed the ability of a musician to master the Eastern tradition of the highest form of Western European polyphony - fugues. On the conclusions we can say the following: 1. Musical forms of the twentieth century. so individualized that they need to be systematized according to a single functional and thematic criterion. The systematics of forms is directly dependent on the structural complication in three ways, starting from the category of the topic; the content of specific classes of musical forms, as well as their interposition, is partially changed. 2. In the works of Chinese composers of the twentieth century, whose works form the basis of teaching the course “analysis of musical works” in the university system of China, the principle of “renewal of typical structures” prevails. The assimilation of the typological foundations of musical composition and the integration of innovative ideas in the national in-tonational soil - this is the modern life of the historical and stylistic systematics of musical forms in Chinese music of the academic tradition. A new understanding of the form as a composition does not restrict its understanding (as it may seem at first glance), but, on the contrary, includes all the historically established factors of the organization of the whole, both traditional (vertical, horizontal) and the newest (atonality, series, structure polyphony of layers). This was demonstrated by the analysis of the Chen Mingzhi polyphonic cycle “13 preludes and fugues”. 3. The criterion for the study of the latest (including Chinese) music of the twentieth century in the mirror of classical typology is the value of nationally original forms of musical thinking (thematic, harmonic, texture-timbre, structural). At the same time, the general laws of the functional logic of the created musical composition in the unity of space-time parameters became the norm of artistic typology in music for Chinese composers and performers.
The evaluation of childhood trauma is essential for the treatment of schizophrenia. The short form of Childhood Trauma Questionnaire (CTQ-SF) is a widely used measure of the experience of childhood ...trauma in the general population. Nevertheless, data regarding the psychometric property of CTQ-SF for assessing childhood trauma of patients with schizophrenia are very limited.
Two hundred Chinese inpatients with schizophrenia completed the Chinese CTQ-SF, the Child Psychological Maltreatment Scale (CPMS), the Impact of Events Scale-Revised (IES-R), and the Dissociative Experiences Scale-II (DES-II). To assess test-retest reliability of the CTQ-SF, all patients completed the CTQ-SF again two weeks later. Concurrent and convergent validity was assessed by analyzing Pearson bivariate correlation coefficients between CTQ-SF and CPMS, IES-R, and DES-II.
The Cronbach's α coefficient of the Chinese CTQ-SF was 0.81, and the two-week re-test reliability was 0.81 (P<0.01). The criterion-related validity coefficients of CTQ-SF with the CMPS, IES-R and DES-II were 0.61, 0.41, and 0.51, respectively.
The Chinese CTQ-SF has satisfactory psychometric properties to measure childhood abuse or neglect in Chinese inpatients with schizophrenia.
The focus of this paper is to reconstruct late Quaternary wildfire and vegetation history in Chinese Loess Plateau (CLP) region, and to determine the interrelationships between wildfire, climate, and ...vegetation. To achieve this aim, we analyzed the black carbon concentration and pollen assemblages within an interval correlated with Marine Isotope Stage (MIS) 5 (equivalent to paleosol S1) to MIS 4–2 (equivalent to Loess L1) in the Xifeng section of the CLP. Findings show that during the MIS 5–2 intervals, changes in precipitation and temperature were essentially synchronous on the CLP, and changes in biomass reflected by total organic carbon content and pollen assemblages were determined mainly by the climatic conditions. Wildfire was controlled mainly by fuel humidity and vegetation type, which influenced by precipitation; however, there was no significant relationship between wildfire occurrence and temperature or the amount of combustible plant material. During the MIS 5 interval, the climate was warmer and wetter than today, while during the MIS 3 interval (Loess L1SL1) it was similar to today; however, during the MIS 2 (L1LL1) and MIS 4 (L1LL2) the climate was cooler and drier. Fires were less frequent during the MIS 5 interval compared to the MIS 3, and fires during the MIS 2 and MIS 4 were more frequent than the MIS 3. Results suggested that if the climate on the CLP became warmer and wetter in the future, natural fires would not necessarily occur more frequently and intensively. However, if climate evolved towards cooler and drier conditions, natural fires may be more likely to occur.
•We reconstructed the wildfire and vegetation history during the MIS 5–2 intervals on the Chinese Loess Plateau.•Biomass changes reflected by total organic carbon and pollen concentration were controlled mainly by climatic conditions.•Fire occurrence was controlled mainly by fuel humidity and vegetation type, which influenced by precipitation.•Warmer and wetter climatic conditions in the future may not result in more natural fires.