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As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O 2 reduction preferentially takes place on Fe III in the FeN 4  /C system with intermediate spin state which possesses one e g electron (t 2g 4e g 1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the Fe III sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO 4 ), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm −2 and long-term durability in reversible zinc–air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts. The working mechanism of several low-cost electrocatalyst materials is still arguable. Here the authors show a model Fe,Mn/N-C catalyst where the oxygen reduction preferentially takes place on Fe(III) sites with the intermediate spin state (t2g4 eg1) caused by the adjacent Mn-N moieties.

Food security plays an important role in maintaining national stability and sustainable development of human society, and its research has become a hot issue at present. Shandong is the main grain producing area in China, and its grain production plays an important role in national food security. Accordingly, this paper is based on the county climate change, grain yield, sown area, fertilizer use, total power of rural machinery, and total population data in Shandong Province from 1995 to 2020. The evolution process of the food security pattern was studied by the methods of spatial analysis and comprehensive evaluation, the influencing factors of food security were quantitatively analyzed, and the adaptive countermeasures to alleviate the food security risks in this region were discussed. The results show that: Grain production increased by 30.62% from 1995 to 2020. The total population and per capita food availability also increased. Since 2000, more than a quarter of counties have experienced a high risk of food insecurity. The spatial agglomeration of grain production was enhanced, and the local agglomeration characteristics were significantly different. The average temperature in the growing season, the sown area, and the total power of agricultural machinery had a significant positive impact on grain production, while the annual average temperature had a significant negative impact on grain production. Improving the food supply system, strengthening the protection of cultivated land, improving the efficiency of fertilizer utilization, and increasing investment in agricultural science and technology can effectively alleviate food security risks.

This paper focuses on county-level grain production and food security in North China; selects 17 indicators from both climatic conditions and human activities; applies yield fluctuation coefficients, spatial econometric modelling, the random forest method, and factor analysis to study the characteristics of grain production in North China and the influencing factors; and evaluates the situation of food security in North China based on grain production capacity. The following results were obtained: (1) The spatial and temporal changes in grain production located in North China from 2000 to 2020 are obvious. The grain output in North China from 2000 to 2020 maintains fluctuating growth at a rate of 0.38 × 1011 kg/10a. The east and south are the key areas for grain production in North China. Grain output was relatively stable except for 2003. with the cold spots of grain production being mainly in the northwestern area and the hot spots in the central and southern areas. (2) The changes in grain production in North China from 2000 to 2020 were less affected by climate and mainly influenced by human activity indicators. (3) As time progresses, the area of food shortage zones decreases in size, becoming evenly distributed and dispersed from the initial concentration in northern Hebei and most of Shanxi; the change in the supply–demand equilibrium zones is not obvious; and the area of surplus grain zones increases markedly in size, with a tendency to expand from the south and centre of the study area to the west and north. The grain production capacity of counties in the northwest and north is generally low, and even counties located in surplus grain areas have potential food security risks. However, in the east and south, due to their high grain production capacity, the per capita grain supply situation may be alleviated even in counties located in grain shortage areas. This study can deepen the understanding of the characteristics of food production in North China and enrich the research on food security. Analyses of factors influencing food production will improve a deeper understanding of food security. Food security evaluation based on food production capacity will contribute to a more precise and comprehensive understanding of the food security pattern in North China.

Suffering from the double blow of the new crown pneumonia epidemic and floods, food security issues have once again become a source of concern. Eastern Gansu is an important dry farming area in northwestern China, and agricultural production has been greatly affected by climate change. Based on the climate data of 17 national meteorological stations in eastern Gansu from 1961 to 2020 and the data on population, grain planting area and grain production in each region from 1986 to 2019, using the Thornthwaite Memorial model, this paper analyzed the climate production potential (TSPV), population carrying capacity and population carrying capacity index in eastern Gansu, and then revealed the relationship between population and food in eastern Gansu. The findings and results revealed that: (1) over the past 60 years, the temperature in eastern Gansu has been increasing and precipitation has been decreasing; (2) TSPV has been increasing. Moreoever, the spatial distribution was significantly different, showing a trend of decreasing from the southeast to the northwest. Lintao, Huining, and Jingtai displayed a decreasing trend, while other areas exhibited an increasing trend. Precipitation was the main limiting factor for TSPV; (3) Grain production continued to increase due to changing hydrothermal conditions and improved production efficiency. Cultivated land–population carrying capacity and climate production potential–population carrying capacity (TSPV–population carrying capacity) both exhibited a significant increasing trend (p < 0.01). Cultivated land–population capacity increased from southeast to northwest, and all stations expressed an increasing trend. TSPV–population carrying capacity increased from southeast to northwest, and the whole region displayed an increasing trend. Even in extremely reduced production years, TSPV–population carrying capacity was also greater than cultivated land–population carrying capacity. This revealed that, under ideal conditions, TSPV–population carrying capacity can fully meet the needs of the current population. (4) The population carrying capacity index showed a significant downward trend (p < 0.01). It showed a trend of decreasing from south to north, and whole area underwent a decreasing trend consistently, indicating that the population–food relationship in eastern Gansu tended to be balanced. This result was conducive to correct assessment of the relationship between people and food in the study area, and provided a reference for formulating food policies.

Weeds have continually interrupted crop plants since their domestication, leading to a greater yield loss compared to diseases and pests that necessitated the practice of weed control measures. The control of weeds is crucial to ensuring the availability of sufficient food for a rapidly increasing human population. Chemical weed control (herbicides) along with integrated weed management (IWM) practices can be the most effective and reliable method of weed management programs. The application of herbicides for weed control practices calls for the urgency to develop herbicide-resistant (HR) crops. Recently, genome editing tools, especially CRISPR-Cas9, have brought innovation in genome editing technology that opens up new possibilities to provide sustainable farming in modern agricultural industry. To date, several non-genetically modified (GM) HR crops have been developed through genome editing that can present a leading role to combat weed problems along with increasing crop productivity to meet increasing food demand around the world. Here, we present the chemical method of weed control, approaches for herbicide resistance development, and possible advantages and limitations of genome editing in herbicide resistance. We also discuss how genome editing would be effective in combating intensive weed problems and what would be the impact of genome-edited HR crops in agriculture.

With global warming, the frequency of drought in China is gradually increasing. The study of drought characteristics and its impact on crop yield is of great significance to ecological construction and food security. Based on the SPEI index in Xinjiang from 1961 to 2020, the changing characteristics of drought and their responses to meteorological yield of three kinds of crops (cotton, wheat and corn) were analyzed. The results revealed that the SPEI in Xinjiang exhibited a decreasing trend. Drought occurred less during 1961–1996 and mainly occurred during 1997–2020. The annual variation trend of SPEI decreased regionally, and the arid trend increased from northwest to southeast. The seasonal variation in SPEI displayed an increasing trend only in winter, but a decreasing trend in spring, summer and autumn. The decreasing trend of the SPEI index in spring accounted for 90.91%, mainly distributed in the central and eastern part of Xinjiang; the decreasing trend in summer accounted for 81.82%, mainly located in the eastern part of Xinjiang; the decreasing trend in autumn accounted for 84.85%, mainly located in the south and central and eastern part of Xinjiang; the decreasing trend in winter accounted for only 33.33%, mainly located in the southwest, central and eastern part of Xinjiang; the per unit area yield of the three kinds of crops showed a significant increasing trend (p < 0.01). The meteorological yield of cotton showed an increasing trend, while that of wheat and corn showed a decreasing trend. Correlation analysis of climatic yield and SPEI, and regression analysis of standardized climatic yield residuals and SPEI in different seasons revealed that drought in spring and autumn had the greatest effect on the meteorological yield of cotton, while drought in spring and summer had the greatest effect on the meteorological yield of wheat and corn.

Tobacco is an important non-food crop with many applications, which is widely cultivated worldwide. Genetic linkage maps play an important role in QTL mapping, gene cloning, marker assistant selection, and genome assembly However, due to the narrow genetic background and large genome of tobacco, the research on the tobacco genetic map lags behind. At present, although several linkage maps have been constructed based on SSR (simple sequence repeat) markers, different SSR markers limit their widespread applications. In order to construct an integrated linkage map, we identified the redundancy of tobacco SSR markers, and constructed a high-quality genetic map by using the integration method based on four tobacco genetic maps. Finally, 20 redundant markers were found from 3.354 SSR markers, and the integrated high-density genetic linkage map (IHD) had a total of 3.377 loci with a length of 2.489.82 cM and a density of 1.36 locus/cM. The high-density integrated genetic map will have great application in the field of QTL mapping and marker-assisted breeding in tobacco.

Over-the-shoulder dialogue videos are essential in films, short dramas, and advertisements, providing visual variety and enhancing viewers' emotional connection. Despite their importance, such dialogue scenes remain largely underexplored in video generation research. The main challenges include maintaining character consistency across different shots, creating a sense of spatial continuity, and generating long, multi-turn dialogues within limited computational budgets. Here, we present ShoulderShot, a framework that combines dual-shot generation with looping video, enabling extended dialogues while preserving character consistency. Our results demonstrate capabilities that surpass existing methods in terms of shot-reverse-shot layout, spatial continuity, and flexibility in dialogue length, thereby opening up new possibilities for practical dialogue video generation. Videos and comparisons are available at https://shouldershot.github.io.

In recent years, generative artificial intelligence has achieved significant advancements in the field of image generation, spawning a variety of applications. However, video generation still faces considerable challenges in various aspects, such as controllability, video length, and richness of details, which hinder the application and popularization of this technology. In this work, we propose a controllable video generation framework, dubbed MimicMotion, which can generate high-quality videos of arbitrary length mimicking specific motion guidance. Compared with previous methods, our approach has several highlights. Firstly, we introduce confidence-aware pose guidance that ensures high frame quality and temporal smoothness. Secondly, we introduce regional loss amplification based on pose confidence, which significantly reduces image distortion. Lastly, for generating long and smooth videos, we propose a progressive latent fusion strategy. By this means, we can produce videos of arbitrary length with acceptable resource consumption. With extensive experiments and user studies, MimicMotion demonstrates significant improvements over previous approaches in various aspects. Detailed results and comparisons are available on our project page: https://tencent.github.io/MimicMotion .