Single-atom catalysts based on polarization switching of ferroelectric In_(2)Se_(3) for N_(2) reduction

The polarization switching plays a crucial role in controlling the final products in the catalytic pro-cess.The effect of polarization orientation on nitrogen reduction was investigated by anchoring transition metal atoms to form active centers on ferroelectric material In_(2)Se_(3).During the polariza-tion switching process,the difference in surface electrostatic potential leads to a redistribution of electronic states.This affects the interaction strength between the adsorbed small molecules and the catalyst substrate,thereby altering the reaction barrier.In addition,the surface states must be considered to prevent the adsorption of other small molecules(such as *O,*OH,and *H).Further-more,the V@↓-In_(2)Se_(3) possesses excellent catalytic properties,high electrochemical and thermody-namic stability,which facilitates the catalytic process.Machine learning also helps us further ex-plore the underlying mechanisms.The systematic investigation provides novel insights into the design and application of two-dimensional switchable ferroelectric catalysts for various chemical processes.

Synthesis and properties of single-crystal Ni-rich cathode materials in Li-ion batteries

Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2(SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. Electrochemical performance was characterized by long-term cycling, cyclic voltammetry, and in-situ impedance spectroscopy. The results indicated that high temperature rendered layered oxides to lose lithium/oxygen in the interior and exterior, and induced cationic disordering. Besides, the solid-phase synthesis process promoted phase transformation for electrode materials, causing the coexisting multi-phase in a single particle. High temperature can foster the growth of single particles, but it caused unstable structure of layered phase.

论经营者集中反垄断审查中的“皇冠宝石”制度--兼评《关于经营者集中附加限制性条件的规定(征求意见稿)》第19条

皇冠宝石制度主要是指在附加剥离限制性条件批准企业合并时,竞争执法机构可要求当事人承诺剥离构成范围不同的两套资产包,若首选的剥离方案失败,则启动替代性的剥离方案。皇冠宝石制度对降低经营集中附限制性条件的实施风险具有重要的意义。我国立法上借鉴这一制度时,应将其外延拓展至附加行为性条件的案件之中,并以具体列举的方式明确适用条件。实践中,竞争执法机构应坚持审慎、严格的立场,并通过保密规则、先行购买制度优先适用等一系列机制克服皇冠宝石制度实施所产生的负面影响。

Isolation and Genetic Analysis of Halophilous Bacteria from Marine Sediment Collected at Tianjin Port, China

[Objective] Marine sediment from Tianjin Port has a extremely high salinity.The bacteria which live in such habitats have evolved distinct physiological,metabolic,and morphological characteristics to survive.The objective of this study is to identify all the specific salt-tolerant characteristics and the genetic evolution of the bacteria in the sediment.[Methods] In this study,the total DNA of sediment from Tianjin Port was extracted,and 16S rDNA was used to conduct an analysis of the fauna of sediment bacteria. We also isolated sediment bacteria using beef extract-peptone media with seven different NaCl concentrations (0,0.5%,2%,5%,10%,15%,and 20%),aiming to analyze the dominant species of halophilous bacteria under different salinities.[Results] 1) With each stepwise increase of salinity from 0.5% to 20%,the total number of isolated bacterial colonies decreased.14 strains of bacteria were identified and classified by the16S rDNA sequencing analysis.Of these,four could tolerate 0~2% salinity,four could tolerate 0~5% salinity,one could tolerate 0~15% salinity,and one tolerated within the full 0~20% salinity range.Further four strains were only able to tolerate within a few narrow salinity ranges.such as 5%~10%,10%~15%,10%~20% and 15%~20%;2) The quantity of bacteria strains that can be isolated from the marine sediment decreased with the increase of salinity. Also, the Shannon wiener index and species richness index of marine sediment bacteria decreased significantly from 5% salinity.However,there were no significant differences in the species evenness index;3) When the salinity was 0~10%,the dominant species was Bacillus.When the salinity was 15%, Halomonas was the dominant species.When the salinity was 20%,there were no significant differences in the proportions of these species.[Conclusion] Our results showed that some bacteria could tolerate living conditions with high salinity,and we even found a species which can tolerate a wide range of salinities (0~20%).In further study,it would be valuable to analyze these bacteria's unique physiological and biochemical functions that allow them to adapt to environments with high salinity.It can provide theories to promote the development of microbial population resources in marine sediment and the reclaimation of salinized soil by salt tolerant microorganisms.

反应堆放射性含硼废液固化的研究

本文对反应堆排出含硼废液水泥固化问题进行了一系列的实验研究，根据实验分析结果，得到了三个较好的技术配方，它们具有实际应用价值。

Photoelectrochemical nitrogen reduction:A step toward achieving sustainable ammonia synthesis

Industrial NH3 production mainly employs the well‐known Haber‐Bosch(H‐B)process,which is associated with significant energy consumption and carbon emissions.Photoelectrochemical nitro‐gen reduction reaction(PEC‐NRR)under ambient conditions is considered a promising alternative to the H‐B process and has been attracting increasing attention owing to its associated energy effi‐ciency and environmentally friendly characteristics.The performance of a PEC‐NRR system,such as the NH_(3) yield,selectivity,and stability,is essentially determined by its key component,the photo‐cathode.In this review,the latest progress in the development of photocathode materials employed in PEC‐NRR is evaluated.The fundamental mechanisms and essential features required for the PEC‐NRR are introduced,followed by a discussion of various types of photocathode materials,such as oxides,sulfides,selenides,black silicon,and black phosphorus.In particular,the PEC‐NRR reac‐tion mechanisms associated with these photocathode materials are reviewed in detail.Finally,the present challenges and future opportunities related to the further development of PEC‐NRR are also discussed.This review aims to improve the understanding of PEC‐NRR photocathode materials while also shedding light on the new concepts and significant innovations in this field.

Phosphorene-Based van der Waals Heterojunction for Solar Water Splitting

As a clean and renewable future energy source, hydrogen fuel can be produced via solar water splitting. Two-dimensional (2D) black phosphorene (black-P) can harvest visible light due to the desirable band gap, which promises it as a metal-free photocatalyst. However, black-P can be only used to produce hydrogen since the oxidation potential of water locates lower than the position of the valence band maximum. To improve the photocatalytic performance of black-P, here, using black-P and blue phosphorene (blue-P) monolayers, we propose a 2D van der Waals (vdW) heterojunction. Theoretical results, including the band structures, density of states, Bader charge population, charge density di erence, and optical absorption spectra, clearly reveal that the visible light absorption ability is obviously improved, and the band edge alignment of the proposed vdW heterojunction displays a typical type-II feature to effectively separate the photogenerated carriers. At the same time, the built-in interfacial electric field prevents the electron-hole recombination. These predictions suggest that the examined phosphorene-based vdW heterojunction is an efficient photocatalyst for solar water splitting.

Transformative Learning:Intercultural Adaptation of Chinese Teachers at the Confucius Institute in Spain

In recent years there has been a proliferation of studies demonstrating the value of teaching abroad as much for its benefits for the training and professional development of these teachers,as for its impact and beneficial effects on students.This article uses transformative learning as a theoretical framework to interpret the achievements associated with the experience of teaching abroad,and to identify and analyze different motivational factors,adjustments,changes,challenges,and perspectives of Chinese teachers linked to a Confucius Institute in Spain,through a qualitative analysis of narratives elicited through in-depth interviews and focus groups.It highlights the role and potential of the transnational,intercultural experience of these teachers as authentic actors in the part played by the Confucius Institutes in language teaching and the promotion of Chinese culture,indicating many issues including language difficulties,professional adjustment,ideas about education,beliefs of teachers and the management of the program.

g-C3N4/SnS2 Heterostructure： a Promising Water Splitting Photocatalyst

Graphite-like carbon nitride （g-C3N4） based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic structures and optical absorption of the proposed g-CaN4/SnS2 heterostructure through performing extensive hybrid functional calculations. The obtained geometric structure, band structures, band edge positions and optical absorptions clearly reveal that the g-C3N4 monolayer weakly couples to SnS2 sheet, and forms a typical van der Waals heterojunction. The g-C3N4/SnS2 heterostructure can effectively harvest visible light, and its valence band maximum and conduction band minimum locate in energetically favorable positions for both water oxidation and reduction reactions. Remarkably, the charge transfer from the g-C3N4 monolayer to SnS2 sheet leads to the built-in interface polarized electric field, which is desirable for the photogenerated carrier separation. The built-in interface polarized electric field as well as the nice band edge alignment implys that the g-CaN4/SnS2 heterostructure is a promising g-CaN4 based water splitting photocatalyst with good performance.

鲁迅杂文的批判性

鲁迅的杂文具有深刻的批判性、强烈的否定性和攻击性。鲁迅杂文以博大精深的思想内涵和独特完美的艺术形式,攀上了中国文学的高峰,进入了"高尚的文学楼台"。

Non-Word Repetition Performance in Mandarin-Speaking Preschool Children With and Without Specific Language Impairment(SLI)

Childhood is a critical period for language development, and it is of great importance to discover normal language development and any specific language impairment （SLI） in child language acquisition and then to give them timely diagnosis and treatment. Also it has been previously shown that the non-word repetition task is an efficient assessment tool to screen out those children suspected with SLI. Based on this premise, the present study examined whether the non-word repetition task can be a suitable screening tool to detect language disorders for preschool children in Mandarin Chinese in China. A non-word repetition task was adapted specifically for this purpose. This study examined differences in non-word repetition performance of Mandarin-speaking preschool children screened by a criterion-referenced diagnostic test of specific language impairment （SLI） （the value of Cronbach Alpha at 0.86）. A sample of 282 children were administered the diagnostic test, and a total of 23 SLI suspects were screened out as their language ability measures deviated from the mean by 1.5 SDs. Results indicated that children with SLI made no error with respect to tone in Mandarin, but they showed great difficulty in non-word repetition skills compared to age-matched controls. The findings confirmed that the non-word repetition task is a culturally nonbiased index of language disorders, and that two syllable non-words can be used to identify language disorder.