Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental i...Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental issues known to influence the growth of invasive plants. Notably, the N/P ratio in the environments is often inconstant;however, whether these variations can cause differential responses in invasive plants remains underexplored, despite its crucial importance for understanding plant invasiveness. In this study, we examined the effects of different N/P ratios (4:1, 16:1, 32:1, 64:1) on the growth of a widespread invasive plant Alternanthera philoxeroides in cadmium (Cd) polluted water, while maintaining either a constant N concentration (2 mmol L^(−1)) or a constant P concentration (0.5 mmol L^(−1)). Two control treatments were also included: one without Cd, N, or P, and another with Cd but without N or P. The addition of N and P did not mitigate the inhibitory effects of Cd on A. philoxeroides growth nor did it enhance its tolerance. However, under conditions of constant N concentration, the N/P ratio of 4:1 significantly increased both the main stem length and the number of nodes in A. philoxeroides under Cd stress, potentially enhancing its expansion and clonal growth. Our results suggest that A. philoxeroides exhibits greater sensitivity to variations in the N/P ratio when N concentration is held constant, compared to when P concentration is constant in Cd polluted water. This study investigated the effects of varying N/P ratios on invasive plants under Cd pollution, which has been underexplored in previous research. The findings provide an experimental basis for controlling and preventing the spread of invasive plants in freshwater systems polluted with Cd and experiencing eutrophication.展开更多
[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects...[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects of Zn on the yield,N/P/K /Zn uptake and distribution of different genotypes of maize were studied by pot cultivation.[Result] Appropriate Zn supply could improve the grain number per kernel.The Zn content in different organs of maize showed little difference under low Zn treatment （Zn0,Zn1）.With the increase of Zn supply,Zn content in leaf,stem and sheath rapidly increased,but the increasing amplitude of Zn content in the kernel and bract were less.The excessive Zn in maize was mainly translocated in lower organs to reduce the damage of them to plants.Different Zn supply levels had less effects on the absorption and translocation of N,P and K in low-Zn insensitive variety Mudan 9.While the absorption and translation of N,P,K in low Zn sensitive variety （Sidan 19） was more easily influenced by the amount of Zn supplied.[Conclusion] Appropriate Zn supply could enhance the maize yield and utilization rate of N and K,and reduce the absorption and utilization of P.展开更多
Silicon(Si)is a promising anode candidate for next-generation lithium-ion batteries(LIBs),but it suffers from poor electronic conductivity and dramatic volume variation during cycling,which poses a critical challenge ...Silicon(Si)is a promising anode candidate for next-generation lithium-ion batteries(LIBs),but it suffers from poor electronic conductivity and dramatic volume variation during cycling,which poses a critical challenge for stable battery operation.To mitigate these issues simultaneously,we propose a"double carbon synergistic encapsulation"strategy,namely thin carbon shell and nitrogen/phosphorus co-doped two-dimensional(2D)carbon sheet dual encapsulate Si nanoparticles(denoted as 2D NPC/C@Si).This double carbon structure can serve as a conductive medium and buffer matrix to accommodate the volume expansion of Si nanoparticles and enable fast electron/ion transport,which promotes the formation of a stable solid electrolyte interphase film during cycling.Through structural advantages,the resulting 2 D NPC/C@Si electrode demonstrates a high reversible capacity of592 mAh·g^(-1) at 0.2 A·g^(-1) with 90.5%excellent capacity retention after 100 cycles,outstanding rate capability(148 mAh·g^(-1) at 8 A·g^(-1)),and superior long-term cycling stability(326 mAh·g^(-1) at 1 A·g^(-1) for 500 cycles,86%capacity retention).Our findings elucidate the development of high-performance Si@C composite anodes for advanced LTBs.展开更多
Immobilizing primary electroactive nanomaterials in porous carbon matrix is an effective approach for boosting the electrochemical performance of potassium-ion batteries (PIBs) because of the synergy among functional ...Immobilizing primary electroactive nanomaterials in porous carbon matrix is an effective approach for boosting the electrochemical performance of potassium-ion batteries (PIBs) because of the synergy among functional components. Herein, an integrated hybrid architecture composed of ultrathin Cu_(3)P nanoparticles (~20 nm) confined in porous carbon nanosheets (Cu_(3)P⊂NPCSs) as a new anode material for PIBs is synthesized through a rational self-designed self-templating strategy. Benefiting from the unique structural advantages including more active heterointerfacial sites, intimate and stable electrical contact, effectively relieved volume change, and rapid K^(+) ion migration, the Cu_(3)P⊂NPCSs indicate excellent potassium-storage performance involving high reversible capacity, exceptional rate capability, and cycling stability. Moreover, the strong adsorption of K^(+) ions and fast potassium-ion reaction kinetics in Cu_(3)P⊂NPCSs is verified by the theoretical calculation investigation. Noted, the intercalation mechanism of Cu_(3)P to store potassium ions is, for the first time, clearly confirmed during the electrochemical process by a series of advanced characterization techniques.展开更多
The carbon materials as anode electrodes have been widely studied for potassium ion batteries(PIBs).However,the large size of potassium ions prevents their intercalation/deintercalation,resulting in poor storage behav...The carbon materials as anode electrodes have been widely studied for potassium ion batteries(PIBs).However,the large size of potassium ions prevents their intercalation/deintercalation,resulting in poor storage behaviors.Herein,a novel design of N/S codoped hierarchical carbonaceous fibers(NSHCF)formed from nanosheets self-assembled by catalyzing Aspergillus niger with Sn is reported.The asprepared NSHCF at 600℃(NSHCF-600)exhibits a high reversible capacity of 345.4 m Ah g^(-1) at 0.1 A g^(-1) after 100 cycles and an excellent rate performance of 124.5 m Ah g^(-1) at 2 A g^(-1).The excellent potassium storage performance can be ascribed to the N/S dual-doping,which enlarges interlayer spacing(0.404 nm)and introduces more defects.The larger interlayer spacing and higher pyridinic N active sites can promote K ions diffusion and storage.In addition,the ex situ transmission electron microscopy reveals the high reversibility of potassiation/depotassiation process and structural stability.展开更多
Lithium-sulfur(Li-S) batteries are promising energy-storage devices for future generations of portable electronics and electric vehicles because of the outstanding energy density,low cost,and nontoxic nature of S.In t...Lithium-sulfur(Li-S) batteries are promising energy-storage devices for future generations of portable electronics and electric vehicles because of the outstanding energy density,low cost,and nontoxic nature of S.In the past decades,various novel electrodes and electrolytes have been studied to improve the performance of Li-S batteries.However,the very limited lifespan and rate performance of Li-S batteries originating from the dissolution and diffusion of long-chain polysulfides in liquid electrolytes,and the intrinsic poor conductivity of S severely hinder their practical application.Herein,an electrospinning method was developed to fabricate a thin conductive interlayer consisting of meso-/microporous N/O dual-doping carbon nanofiber(CNF).The freestanding 3 D interwoven structure with conductive pathways for electrons and ions can enhance the contact between polysulfides and N/O atoms to realize the highly robust trapping of polysulfides via the extremely polar interaction.Consequently,combining the meso-microporous N/O dual-doping CNF interlayer with a monodispersed S nanoparticle cathode results in a superior electrochemical performance of 862.5 mAh/g after 200 cycles at 0.2 C and a cycle decay as low as 0.08% per cycle.An area specific capacity of 5.22 mAh/cm^(2) can be obtained after 100 cycles at 0.1 C with a high S loading of 7.5 mg/cm^(2).展开更多
WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,t...WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.展开更多
Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metaboli...Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metabolism,causing restructuring of carbon and nitrogen balance in crops. Though elevated CO_(2)(eCO_(2)) increases photosynthetic efficacy and biomass accumulation in many C3crops, it also disrupts carbon-nitrogen balance, leading to nitrogen dilution in leaves and grains, eventually compromising food quality(Myers et al., 2014;Rezaei et al., 2023). Rice is a staple food that feeds nearly half of the world's population;it requires sustained yield gains, considering an estimated 35%-56%increase in demand by 2050, as the global population approaches 10 billion(Van Dijk et al., 2021), while reducing dependency on nitrogen fertilizers, whose production and overuse contribute significantly to greenhouse gas emission(Qian et al., 2023). Yet, most breeding programs remain regulated to present-day atmospheric conditions, overlooking the physiological and molecular adaptations required for future CO_(2)climates.展开更多
[Objectives]To investigate the effects of different planting densities and nitrogen application rates on the yield and quality of the tobacco cultivar Chuxue 80.[Methods]A field experiment was conducted in Hubei Provi...[Objectives]To investigate the effects of different planting densities and nitrogen application rates on the yield and quality of the tobacco cultivar Chuxue 80.[Methods]A field experiment was conducted in Hubei Province,evaluating various combinations of planting density and nitrogen rate for Chuxue 80.[Results]At the maturity stage,the TN1 treatment(5 kg N per 667 m^(2) with a density of 1900 plants per 667 m^(2))demonstrated the most favorable agronomic performance.The TN9 treatment(11 kg N per 667 m^(2) with a density of 1110 plants per 667 m^(2))achieved the highest wrapper tobacco yield and output value.Meanwhile,the TN5 treatment(8 kg N per 667 m^(2) with a density of 1515 plants per 667 m^(2))resulted in the best smoking quality.[Conclusions]The TN9 treatment,with a planting density of 1110 plants per 667 m^(2) and a nitrogen application rate of 11 kg per 667 m^(2),is recommended as the optimal cultivation practice for Chuxue 80 in Hubei Province.展开更多
A novel salt-tolerant aerobic denitrifying bacterium,Marinobacter sp.strain B108,was isolated from a marine recirculating aquaculture system(MRAS).The optimal aerobic denitrification parameters were CH_(3)COONa as car...A novel salt-tolerant aerobic denitrifying bacterium,Marinobacter sp.strain B108,was isolated from a marine recirculating aquaculture system(MRAS).The optimal aerobic denitrification parameters were CH_(3)COONa as carbon source,pH of 8,C/N of16,temperature of 35°C,dissolved oxygen(DO)of 6 mg/L and salinity of 30.Under these optimal conditions,Marinobacter sp.strain B108 had a removal efficiency of 100%for N O_(3)^(-)-N and 98.89%for total nitrogen(TN)within 24 h.The nitrate removal pathways of Marinobacter sp.strain B108 were included by the assimilative reduction pathway(N O_(3)^(-)-N→biomass N)and the dissimilatory reduction pathway(N O_(3)^(-)-N→N_(2))of aerobic denitrification,and lack of dissimilatory reduction to ammonium pathway(N O_(3)^(-)-N→N H_(4)^(+)-N).The nitrogen removal process of Marinobacter sp.strain B108 was mainly contributed by the dissimilatory reduction pathway.The kinetic parameters for N O_(3)^(-)-N and N O_(2)^(-)-N removal were determined as V_(m)of 971.566 and 165.336 mg/(gDCW·L·h),and K_(m)of 22.74 and 31.68 mg/L,respectively.This work reflects the practical application potential of Marinobacter sp.strain B108for nitrogen removal in MRAS.展开更多
Ecological floating bed is an important biological remediation method for water pollution control.During the removal of excess nutrients and pollutants,changes in environmental factors affect the characteristics of mi...Ecological floating bed is an important biological remediation method for water pollution control.During the removal of excess nutrients and pollutants,changes in environmental factors affect the characteristics of microorganisms in aquatic ecosystems.To understand the influences of ecological floating beds on size-fractionated microorganisms,we investigated the community assembly and nitrogen metabolic characteristics of three size-fractionated microorganism groups in the ecological floating bed area,using 18S rDNA,16S rDNA metabarcoding,and metagenomic sequencing techniques.Firstly,we discovered substantial differences between size-fractionated groups in the diversity and compositions of both microeukaryotic and bacterial communities,as well as the influences of floating beds on specific groups.The floating beds appeared to provide more habitats for heterotrophs and symbiotes while potentially inhibiting the growth of certain phytoplankton(cyanobacteria).Secondly,we observed that microeukaryotic and bacterial communities were predominantly influenced by stochastic and deterministic processes,respectively,and they both exhibited distinct patterns across different size-fractionated groups.Notably,microeukaryotic community assembly demonstrated a greater sensitivity to ecological floating beds,as indicated by an increase in dispersal limitation processes.Finally,the nitrogen metabolism functional genes revealed that microbes associated with large-sized particles played a crucial role in dissimilatory nitrate reduction to ammonium(DNRA)and denitrification processes within the floating bed area,thereby facilitating the removal of excess nitrogen nutrients from the water.In contrast,freeliving microorganisms from small-sized groups were linked mainly to the genes involved in nitrogen assimilation and assimilatory nitrate reduction to ammonium(ANRA)processes.These findings help understand the impact of ecological floating beds on the diversity and functional characteristics of microorganism communities in different size-fractionated groups.展开更多
Soybean is an important source of oil,protein,and feed.However,its yield is far below that of major cereal crops.The green revolution increased the yield of cereal crops partially through high-density planting of lodg...Soybean is an important source of oil,protein,and feed.However,its yield is far below that of major cereal crops.The green revolution increased the yield of cereal crops partially through high-density planting of lodging-resistant semi-dwarf varieties,but required more nitrogen fertilizers,posing an environmental threat.Genes that can improve nitrogen use efficiency need to be integrated into semi-dwarf varieties to avoid the overuse of fertilizers without the loss of dwarfism.Unlike cereal crops,soybean can assimilate atmospheric nitrogen through symbiotic bacteria.Here,we created new alleles of Gm GID1-2(Glycine max GIBBERELLIN INSENSITIVE DWARF 1-2)using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)editing,which improved soybean architecture,yield,seed oil content,and nitrogen fixation,by regulation of important pathways and known genes related to branching,lipid metabolism,and nodule symbiosis.Gm GID1-2 knockout reduced plant height,and increased stem diameter and strength,number of branches,nodes on the primary stem,pods,and seeds per plant,leading to an increase in seed weight per plant and yield in soybean.The nodule number,nodule weight,nitrogenase activity,and nitrogen content were also improved in Gm GID1-2knockout soybean lines,which is novel compared with the semi-dwarf genes in cereal crops.No loss-of-function allele for Gm GID1-2 was identified in soybean germplasm and the edited Gm GID1-2s are superior to the natural alleles,suggesting the Gm GID1-2 knockout mutants generated in this study are valuable genetic resources to further improve soybean yield and seed oil content in future breeding programs.This study illustrates the pleiotropic functions of the GID1 knockout alleles with positive effects on plant architecture,yield,and nitrogen fixation in soybean,which provides a promising strategy toward sustainable agriculture.展开更多
Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassi...Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.展开更多
Green ammonia,produced by harnessing renewable solar energy to split nitrogen,plays a pivotal role in both agricultural practices and forthcoming energy configurations,driving the sustainable development of human soci...Green ammonia,produced by harnessing renewable solar energy to split nitrogen,plays a pivotal role in both agricultural practices and forthcoming energy configurations,driving the sustainable development of human society with zero-carbon emissions.However,nitrogen photoreduction currently faces the challenges of poor activation ability and low yield,and it is still challenging to unravel the intertwined problems in this field and provide direction for its development due to the complex reaction mechanism and multidisciplinary aspects such as photochemistry,catalysis,interface science,and technology.This review focuses on capturing the latest advances in photocatalytic nitrogen-to-ammonia conversion,delving into fundamental principles regarding the process,efficient photocatalysts for practical ammonia synthesis,and well-designed catalytic environments.Besides,this article provides insightful guidelines for analyzing complicated reaction mechanisms and identifying key bottlenecks or specific rate-determining steps,such as reactant activation,interfacial reaction engineering,and hydrogen evolution side reactions.By integrating perspectives from atomic mechanisms,nanoscale photocatalysts,microscale interfacial engineering,and macroscale reaction system design,this review advances the development of nitrogen photoreduction from proof-of-concept discoveries to viable solar-to-chemical conversion technologies,while also providing a valuable entry point for researchers into this burgeoning field.展开更多
The premature decay of electrochemical nitrogen reduction reaction(eNRR)performance at low electrode potentials remains a major obstacle to practical applications,which is primarily attributed to the competition from ...The premature decay of electrochemical nitrogen reduction reaction(eNRR)performance at low electrode potentials remains a major obstacle to practical applications,which is primarily attributed to the competition from the hydrogen evolution reaction(HER).A new paradigm capable of transcending current selectivity constraints is urgently required to advance eNRR toward industrial implementation.In this work,we propose two practical selectivity descriptors(ΔΔG andΔU)based on a systematic investigation of the potential-dependent competition between eNRR and HER on confined dual-atom catalysts.The descriptorΔΔG(G_(N_(2))-ΔG_(H))identifies the potential range where N_(2)adsorption dominates over H adsorption,whileΔU(U_(cross)-U_(eNRR))specifies the potential range to trigger direct eNRR,offering a quantitative benchmark for rational catalyst design.Ideal catalysts should maintain N_(2)-preferential adsorption across a broad potential window to facilitate direct eNRR.Guided by this insight,we demonstrate that confined dual-atom configurations with optimized interatomic distances can simultaneously achieve both overwhelming N_(2)adsorption and sufficient activation,thereby overcoming the conventional selectivity limitations.This strategy enables ammonia synthesis with industrially relevant production rates and current density even at elevated potentials.Our mechanistic insights not only elucidate the root causes of performance limitations in eNRR but also offer a rational design framework for developing high-performance catalysts across a broad range of electrochemical transformations.展开更多
Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and th...Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.展开更多
Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting d...Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting density and N rate,and their relationships with grain yield,radiation use efficiency(RUE),and N use efficiency for grain production(NUEg)in rice.A two-year field experiment was conducted with two hybrid varieties under three N levels,0 kg ha^(-1)(N1),90 kg ha^(-1)(N2)and 180 kg ha^(-1)(N3),and two planting densities,22.2 hills m-2(D1)and 33.3 hills m^(-2)(D2).Results showed 3.4%higher yield and 4.4%higher NUEg under N2D2 compared with N3D1.The extinction coefficient for N(K_(N))and light(K_(L))and their ratio(K_(N)/K_(L))at heading stage were significantly influenced by N rate,planting density,and their interaction.K_(N)decreased with the increase of N input or planting density.Compared to N1,K_(N)decreased by 43.5 and 58.8%under N2 and N3,respectively,while K_(N)under D2 decreased by 16.0%compared to D1.Higher K_(L)and K_(N)/K_(L)values occurred under low N rates,with opposite trends under high N rates.Increased planting density led to decreased K_(L)and K_(N)/K_(L)values.N2D2 demonstrated higher K_(L)and K_(N),and thus comparable K_(N)/K_(L),compared to N3D1.Correlation analysis revealed K_(L)negatively correlated with RUE,while K_(N)and K_(N)/K_(L)positively correlated with NUEg.These findings indicate that increasing planting density under reduced N input could maintain rice yield while enhancing resource use efficiency through regulation of canopy light and N distribution.展开更多
Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse...Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.展开更多
Changes in the soil environment induced by major global changes in climate are affecting carbon emissions in cold-temperate coniferous forests.A randomized block experiment simulating warming,rainfall increase and nit...Changes in the soil environment induced by major global changes in climate are affecting carbon emissions in cold-temperate coniferous forests.A randomized block experiment simulating warming,rainfall increase and nitrogen addition in a Larix gmelinii forest was carried out to study the effects on soil carbon,nitrogen,and CO_(2)flux during the thawing,growing,and freezing periods.Our study found that warming(0-2.0℃)increased soil organic carbon(SOC)and total nitrogen(STN),dissolved organic carbon(DOC)and dissolved organic nitrogen(DON),and microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN).Warming played a direct role in regulating soil CO_(2)emissions,stimulated microbial and plant root respiration and soil CO_(2)flux rapidly increased.Rainfall increase initially increased soil carbon and nitrogen,but a 30%increase in mean annual rainfall caused losses of SOC,STN,DOC,and DON,while MBC and MBN accumulated.Soil CO_(2)emissions were regulated by MBC after an increase in rainfall,excess moisture inhibited microbial activity,and soil CO_(2)flux showed a trend of R2(20%rainfall increase)>R1(10%rainfall increase)>CK(control)>R3(30%rainfall increase).The addition of nitrogen increased SOC,STN,DOC,DON,MBC and MBN.Soil CO_(2)flux progressively decreased with nitrogen inputs(2.5,5.0 and 10.0 g m^(-2)a^(-1)),as more N intensified plant-microbe competition.Nitrogen addition indirectly regulated soil CO_(2)emissions by altering SOC and STN,with MBC and MBN acting as secondary regulators.The results highlight the role of cold-temperate coniferous forest soils in predicting carbon-climate feedback in high-latitude forest permafrost regions.展开更多
We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptiona...We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32101264)the Science and Technology Research and Development Project of Handan(Grant 23422304086)the National College Student Innovation Training Project of China(Grant No.202410103013).
文摘Plant invasion poses a serious environmental challenge to freshwater ecosystems. Heavy metal pollution and nutrient enrichment, particularly nitrogen (N) and phosphorus (P), are two additional critical environmental issues known to influence the growth of invasive plants. Notably, the N/P ratio in the environments is often inconstant;however, whether these variations can cause differential responses in invasive plants remains underexplored, despite its crucial importance for understanding plant invasiveness. In this study, we examined the effects of different N/P ratios (4:1, 16:1, 32:1, 64:1) on the growth of a widespread invasive plant Alternanthera philoxeroides in cadmium (Cd) polluted water, while maintaining either a constant N concentration (2 mmol L^(−1)) or a constant P concentration (0.5 mmol L^(−1)). Two control treatments were also included: one without Cd, N, or P, and another with Cd but without N or P. The addition of N and P did not mitigate the inhibitory effects of Cd on A. philoxeroides growth nor did it enhance its tolerance. However, under conditions of constant N concentration, the N/P ratio of 4:1 significantly increased both the main stem length and the number of nodes in A. philoxeroides under Cd stress, potentially enhancing its expansion and clonal growth. Our results suggest that A. philoxeroides exhibits greater sensitivity to variations in the N/P ratio when N concentration is held constant, compared to when P concentration is constant in Cd polluted water. This study investigated the effects of varying N/P ratios on invasive plants under Cd pollution, which has been underexplored in previous research. The findings provide an experimental basis for controlling and preventing the spread of invasive plants in freshwater systems polluted with Cd and experiencing eutrophication.
基金Supported by National "11th five-year" Plan Science and Technolo-gy Support Project (2006BAD02A11)"11th five-year plan" of Tackling Key Problems Projects of Heilongjiang Province(GA07B101)~~
文摘[Objective] To study the effects of Zinc on the yield,nitrogen/phosphorus/potassium/Zinc uptake and distribution of different genotypes of maize.[Method] Using two different genotypes of maize as materials,the effects of Zn on the yield,N/P/K /Zn uptake and distribution of different genotypes of maize were studied by pot cultivation.[Result] Appropriate Zn supply could improve the grain number per kernel.The Zn content in different organs of maize showed little difference under low Zn treatment （Zn0,Zn1）.With the increase of Zn supply,Zn content in leaf,stem and sheath rapidly increased,but the increasing amplitude of Zn content in the kernel and bract were less.The excessive Zn in maize was mainly translocated in lower organs to reduce the damage of them to plants.Different Zn supply levels had less effects on the absorption and translocation of N,P and K in low-Zn insensitive variety Mudan 9.While the absorption and translation of N,P,K in low Zn sensitive variety （Sidan 19） was more easily influenced by the amount of Zn supplied.[Conclusion] Appropriate Zn supply could enhance the maize yield and utilization rate of N and K,and reduce the absorption and utilization of P.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52072323,21805278 and 51872098)the Leading Project Foundation of Science Department of Fujian Province(No.2018H0034)+2 种基金the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen Universitythe Opening Project of National Joint Engineering Research Center for Abrasion Control and Molding of Metal MaterialsHenan Key Laboratory of High-temperature Structural and Functional Materials,Henan University of Science and Technology(No.HKDNM2019013)。
文摘Silicon(Si)is a promising anode candidate for next-generation lithium-ion batteries(LIBs),but it suffers from poor electronic conductivity and dramatic volume variation during cycling,which poses a critical challenge for stable battery operation.To mitigate these issues simultaneously,we propose a"double carbon synergistic encapsulation"strategy,namely thin carbon shell and nitrogen/phosphorus co-doped two-dimensional(2D)carbon sheet dual encapsulate Si nanoparticles(denoted as 2D NPC/C@Si).This double carbon structure can serve as a conductive medium and buffer matrix to accommodate the volume expansion of Si nanoparticles and enable fast electron/ion transport,which promotes the formation of a stable solid electrolyte interphase film during cycling.Through structural advantages,the resulting 2 D NPC/C@Si electrode demonstrates a high reversible capacity of592 mAh·g^(-1) at 0.2 A·g^(-1) with 90.5%excellent capacity retention after 100 cycles,outstanding rate capability(148 mAh·g^(-1) at 8 A·g^(-1)),and superior long-term cycling stability(326 mAh·g^(-1) at 1 A·g^(-1) for 500 cycles,86%capacity retention).Our findings elucidate the development of high-performance Si@C composite anodes for advanced LTBs.
基金the financial supports provided by the National Natural Science Foundation of China(Nos.21971145,21871164)the Taishan Scholar Project Foundation of Shandong Province(No.ts20190908)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019MB024)the Young Scholars Program of Shandong University(No.2017WLJH15)。
文摘Immobilizing primary electroactive nanomaterials in porous carbon matrix is an effective approach for boosting the electrochemical performance of potassium-ion batteries (PIBs) because of the synergy among functional components. Herein, an integrated hybrid architecture composed of ultrathin Cu_(3)P nanoparticles (~20 nm) confined in porous carbon nanosheets (Cu_(3)P⊂NPCSs) as a new anode material for PIBs is synthesized through a rational self-designed self-templating strategy. Benefiting from the unique structural advantages including more active heterointerfacial sites, intimate and stable electrical contact, effectively relieved volume change, and rapid K^(+) ion migration, the Cu_(3)P⊂NPCSs indicate excellent potassium-storage performance involving high reversible capacity, exceptional rate capability, and cycling stability. Moreover, the strong adsorption of K^(+) ions and fast potassium-ion reaction kinetics in Cu_(3)P⊂NPCSs is verified by the theoretical calculation investigation. Noted, the intercalation mechanism of Cu_(3)P to store potassium ions is, for the first time, clearly confirmed during the electrochemical process by a series of advanced characterization techniques.
基金financial support from the National Natural Science Foundation of China(NSFC Grant No.21571080)the Project 2019JLP-04 supported by Joint Foundation of ShaanxiXi’an Science and Technology Project of China(201805037YD15CG21(20))。
文摘The carbon materials as anode electrodes have been widely studied for potassium ion batteries(PIBs).However,the large size of potassium ions prevents their intercalation/deintercalation,resulting in poor storage behaviors.Herein,a novel design of N/S codoped hierarchical carbonaceous fibers(NSHCF)formed from nanosheets self-assembled by catalyzing Aspergillus niger with Sn is reported.The asprepared NSHCF at 600℃(NSHCF-600)exhibits a high reversible capacity of 345.4 m Ah g^(-1) at 0.1 A g^(-1) after 100 cycles and an excellent rate performance of 124.5 m Ah g^(-1) at 2 A g^(-1).The excellent potassium storage performance can be ascribed to the N/S dual-doping,which enlarges interlayer spacing(0.404 nm)and introduces more defects.The larger interlayer spacing and higher pyridinic N active sites can promote K ions diffusion and storage.In addition,the ex situ transmission electron microscopy reveals the high reversibility of potassiation/depotassiation process and structural stability.
基金the support from the National Key Research and Development Program(No.2018YFB1107500)the Liao Ning Revitalization Talents Program(No.XLYC1907144)+1 种基金the National Natural Science Foundation of China(No.51503024)the Dalian Youth Science and Technology Star Project Support Program(No.2017RQ104)。
文摘Lithium-sulfur(Li-S) batteries are promising energy-storage devices for future generations of portable electronics and electric vehicles because of the outstanding energy density,low cost,and nontoxic nature of S.In the past decades,various novel electrodes and electrolytes have been studied to improve the performance of Li-S batteries.However,the very limited lifespan and rate performance of Li-S batteries originating from the dissolution and diffusion of long-chain polysulfides in liquid electrolytes,and the intrinsic poor conductivity of S severely hinder their practical application.Herein,an electrospinning method was developed to fabricate a thin conductive interlayer consisting of meso-/microporous N/O dual-doping carbon nanofiber(CNF).The freestanding 3 D interwoven structure with conductive pathways for electrons and ions can enhance the contact between polysulfides and N/O atoms to realize the highly robust trapping of polysulfides via the extremely polar interaction.Consequently,combining the meso-microporous N/O dual-doping CNF interlayer with a monodispersed S nanoparticle cathode results in a superior electrochemical performance of 862.5 mAh/g after 200 cycles at 0.2 C and a cycle decay as low as 0.08% per cycle.An area specific capacity of 5.22 mAh/cm^(2) can be obtained after 100 cycles at 0.1 C with a high S loading of 7.5 mg/cm^(2).
文摘WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas mixtures.Experimental data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.
基金supported by the Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality(No.2023B1212120003)the Guangdong Talent Program(No.2023JC10N060)+1 种基金the Guangdong Science and Technology Program(No.2022B1212040001)the Special Fund for Science and Technology Innovation Strategy of Guangdong Province(Grant No.2022660500250009604)。
文摘Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metabolism,causing restructuring of carbon and nitrogen balance in crops. Though elevated CO_(2)(eCO_(2)) increases photosynthetic efficacy and biomass accumulation in many C3crops, it also disrupts carbon-nitrogen balance, leading to nitrogen dilution in leaves and grains, eventually compromising food quality(Myers et al., 2014;Rezaei et al., 2023). Rice is a staple food that feeds nearly half of the world's population;it requires sustained yield gains, considering an estimated 35%-56%increase in demand by 2050, as the global population approaches 10 billion(Van Dijk et al., 2021), while reducing dependency on nitrogen fertilizers, whose production and overuse contribute significantly to greenhouse gas emission(Qian et al., 2023). Yet, most breeding programs remain regulated to present-day atmospheric conditions, overlooking the physiological and molecular adaptations required for future CO_(2)climates.
基金Supported by Science and Technology Project of China Tobacco Zhejiang Industrial Co.,Ltd.(2023330000340093).
文摘[Objectives]To investigate the effects of different planting densities and nitrogen application rates on the yield and quality of the tobacco cultivar Chuxue 80.[Methods]A field experiment was conducted in Hubei Province,evaluating various combinations of planting density and nitrogen rate for Chuxue 80.[Results]At the maturity stage,the TN1 treatment(5 kg N per 667 m^(2) with a density of 1900 plants per 667 m^(2))demonstrated the most favorable agronomic performance.The TN9 treatment(11 kg N per 667 m^(2) with a density of 1110 plants per 667 m^(2))achieved the highest wrapper tobacco yield and output value.Meanwhile,the TN5 treatment(8 kg N per 667 m^(2) with a density of 1515 plants per 667 m^(2))resulted in the best smoking quality.[Conclusions]The TN9 treatment,with a planting density of 1110 plants per 667 m^(2) and a nitrogen application rate of 11 kg per 667 m^(2),is recommended as the optimal cultivation practice for Chuxue 80 in Hubei Province.
基金National Natural Science Foundation of China(No.51978636)。
文摘A novel salt-tolerant aerobic denitrifying bacterium,Marinobacter sp.strain B108,was isolated from a marine recirculating aquaculture system(MRAS).The optimal aerobic denitrification parameters were CH_(3)COONa as carbon source,pH of 8,C/N of16,temperature of 35°C,dissolved oxygen(DO)of 6 mg/L and salinity of 30.Under these optimal conditions,Marinobacter sp.strain B108 had a removal efficiency of 100%for N O_(3)^(-)-N and 98.89%for total nitrogen(TN)within 24 h.The nitrate removal pathways of Marinobacter sp.strain B108 were included by the assimilative reduction pathway(N O_(3)^(-)-N→biomass N)and the dissimilatory reduction pathway(N O_(3)^(-)-N→N_(2))of aerobic denitrification,and lack of dissimilatory reduction to ammonium pathway(N O_(3)^(-)-N→N H_(4)^(+)-N).The nitrogen removal process of Marinobacter sp.strain B108 was mainly contributed by the dissimilatory reduction pathway.The kinetic parameters for N O_(3)^(-)-N and N O_(2)^(-)-N removal were determined as V_(m)of 971.566 and 165.336 mg/(gDCW·L·h),and K_(m)of 22.74 and 31.68 mg/L,respectively.This work reflects the practical application potential of Marinobacter sp.strain B108for nitrogen removal in MRAS.
基金Supported by the National Natural Science Foundation of China(Nos.42141003,42176147)the National Key Research and Development Program of China(No.2022YFF0802204)the Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration(USER)(Nos.USER2021-1,USER2021-5)。
文摘Ecological floating bed is an important biological remediation method for water pollution control.During the removal of excess nutrients and pollutants,changes in environmental factors affect the characteristics of microorganisms in aquatic ecosystems.To understand the influences of ecological floating beds on size-fractionated microorganisms,we investigated the community assembly and nitrogen metabolic characteristics of three size-fractionated microorganism groups in the ecological floating bed area,using 18S rDNA,16S rDNA metabarcoding,and metagenomic sequencing techniques.Firstly,we discovered substantial differences between size-fractionated groups in the diversity and compositions of both microeukaryotic and bacterial communities,as well as the influences of floating beds on specific groups.The floating beds appeared to provide more habitats for heterotrophs and symbiotes while potentially inhibiting the growth of certain phytoplankton(cyanobacteria).Secondly,we observed that microeukaryotic and bacterial communities were predominantly influenced by stochastic and deterministic processes,respectively,and they both exhibited distinct patterns across different size-fractionated groups.Notably,microeukaryotic community assembly demonstrated a greater sensitivity to ecological floating beds,as indicated by an increase in dispersal limitation processes.Finally,the nitrogen metabolism functional genes revealed that microbes associated with large-sized particles played a crucial role in dissimilatory nitrate reduction to ammonium(DNRA)and denitrification processes within the floating bed area,thereby facilitating the removal of excess nitrogen nutrients from the water.In contrast,freeliving microorganisms from small-sized groups were linked mainly to the genes involved in nitrogen assimilation and assimilatory nitrate reduction to ammonium(ANRA)processes.These findings help understand the impact of ecological floating beds on the diversity and functional characteristics of microorganism communities in different size-fractionated groups.
基金supported by the National Natural Science Foundation of China(32372192)the Core Technology Development for Breeding Program of Jiangsu Province(JBGS-2021-014)Jiangsu Key Laboratory of Soybean Biotechnology and Intelligent Breeding(BM2024005)。
文摘Soybean is an important source of oil,protein,and feed.However,its yield is far below that of major cereal crops.The green revolution increased the yield of cereal crops partially through high-density planting of lodging-resistant semi-dwarf varieties,but required more nitrogen fertilizers,posing an environmental threat.Genes that can improve nitrogen use efficiency need to be integrated into semi-dwarf varieties to avoid the overuse of fertilizers without the loss of dwarfism.Unlike cereal crops,soybean can assimilate atmospheric nitrogen through symbiotic bacteria.Here,we created new alleles of Gm GID1-2(Glycine max GIBBERELLIN INSENSITIVE DWARF 1-2)using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)editing,which improved soybean architecture,yield,seed oil content,and nitrogen fixation,by regulation of important pathways and known genes related to branching,lipid metabolism,and nodule symbiosis.Gm GID1-2 knockout reduced plant height,and increased stem diameter and strength,number of branches,nodes on the primary stem,pods,and seeds per plant,leading to an increase in seed weight per plant and yield in soybean.The nodule number,nodule weight,nitrogenase activity,and nitrogen content were also improved in Gm GID1-2knockout soybean lines,which is novel compared with the semi-dwarf genes in cereal crops.No loss-of-function allele for Gm GID1-2 was identified in soybean germplasm and the edited Gm GID1-2s are superior to the natural alleles,suggesting the Gm GID1-2 knockout mutants generated in this study are valuable genetic resources to further improve soybean yield and seed oil content in future breeding programs.This study illustrates the pleiotropic functions of the GID1 knockout alleles with positive effects on plant architecture,yield,and nitrogen fixation in soybean,which provides a promising strategy toward sustainable agriculture.
基金funded by the National Natural Science Foundation of China (31760363)the Earmarked Fund for CARS (CARS-14-1-16)+1 种基金the Gansu Education Science and Technology Innovation Industry Support Program,China (2021CYZC-38)the Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,China (GSCS-2020-Z6)。
文摘Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.
基金financially supported by the National Energy Green Hydrogen Refining Research&Development Center,National Natural Science Foundation of China(No.22476222)Natural Science Funds of Guangdong for Distinguished Young Scholar(No.2022B1515020098).
文摘Green ammonia,produced by harnessing renewable solar energy to split nitrogen,plays a pivotal role in both agricultural practices and forthcoming energy configurations,driving the sustainable development of human society with zero-carbon emissions.However,nitrogen photoreduction currently faces the challenges of poor activation ability and low yield,and it is still challenging to unravel the intertwined problems in this field and provide direction for its development due to the complex reaction mechanism and multidisciplinary aspects such as photochemistry,catalysis,interface science,and technology.This review focuses on capturing the latest advances in photocatalytic nitrogen-to-ammonia conversion,delving into fundamental principles regarding the process,efficient photocatalysts for practical ammonia synthesis,and well-designed catalytic environments.Besides,this article provides insightful guidelines for analyzing complicated reaction mechanisms and identifying key bottlenecks or specific rate-determining steps,such as reactant activation,interfacial reaction engineering,and hydrogen evolution side reactions.By integrating perspectives from atomic mechanisms,nanoscale photocatalysts,microscale interfacial engineering,and macroscale reaction system design,this review advances the development of nitrogen photoreduction from proof-of-concept discoveries to viable solar-to-chemical conversion technologies,while also providing a valuable entry point for researchers into this burgeoning field.
基金supported by the Taishan Scholar Program of Shandong Province(tsqn202507090)Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZB20250022)+1 种基金Natural Science Foundation of Shandong Province(ZR2025QC1086)Young Talents Project at Ocean University of China。
文摘The premature decay of electrochemical nitrogen reduction reaction(eNRR)performance at low electrode potentials remains a major obstacle to practical applications,which is primarily attributed to the competition from the hydrogen evolution reaction(HER).A new paradigm capable of transcending current selectivity constraints is urgently required to advance eNRR toward industrial implementation.In this work,we propose two practical selectivity descriptors(ΔΔG andΔU)based on a systematic investigation of the potential-dependent competition between eNRR and HER on confined dual-atom catalysts.The descriptorΔΔG(G_(N_(2))-ΔG_(H))identifies the potential range where N_(2)adsorption dominates over H adsorption,whileΔU(U_(cross)-U_(eNRR))specifies the potential range to trigger direct eNRR,offering a quantitative benchmark for rational catalyst design.Ideal catalysts should maintain N_(2)-preferential adsorption across a broad potential window to facilitate direct eNRR.Guided by this insight,we demonstrate that confined dual-atom configurations with optimized interatomic distances can simultaneously achieve both overwhelming N_(2)adsorption and sufficient activation,thereby overcoming the conventional selectivity limitations.This strategy enables ammonia synthesis with industrially relevant production rates and current density even at elevated potentials.Our mechanistic insights not only elucidate the root causes of performance limitations in eNRR but also offer a rational design framework for developing high-performance catalysts across a broad range of electrochemical transformations.
基金funded by the National Key Research and Development Program of China(2024YFD1501602)the National Natural Science Foundation of China(42407437)conducted as part of the Coordinated Research Project D1.50.16,implemented by the Soil and Water Management and Crop Nutrition Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture,Department of Nuclear Sciences and Applications,Vienna,Austria。
文摘Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.
基金supported by the Hubei Provincial Science and Technology Project,China(2025CSA039)the National Natural Science Foundation of China(32001467)。
文摘Coordinating light and nitrogen(N)distribution within a canopy is essential for improving rice yield and resource use efficiency.However,limited research has examined light and N distribution in response to planting density and N rate,and their relationships with grain yield,radiation use efficiency(RUE),and N use efficiency for grain production(NUEg)in rice.A two-year field experiment was conducted with two hybrid varieties under three N levels,0 kg ha^(-1)(N1),90 kg ha^(-1)(N2)and 180 kg ha^(-1)(N3),and two planting densities,22.2 hills m-2(D1)and 33.3 hills m^(-2)(D2).Results showed 3.4%higher yield and 4.4%higher NUEg under N2D2 compared with N3D1.The extinction coefficient for N(K_(N))and light(K_(L))and their ratio(K_(N)/K_(L))at heading stage were significantly influenced by N rate,planting density,and their interaction.K_(N)decreased with the increase of N input or planting density.Compared to N1,K_(N)decreased by 43.5 and 58.8%under N2 and N3,respectively,while K_(N)under D2 decreased by 16.0%compared to D1.Higher K_(L)and K_(N)/K_(L)values occurred under low N rates,with opposite trends under high N rates.Increased planting density led to decreased K_(L)and K_(N)/K_(L)values.N2D2 demonstrated higher K_(L)and K_(N),and thus comparable K_(N)/K_(L),compared to N3D1.Correlation analysis revealed K_(L)negatively correlated with RUE,while K_(N)and K_(N)/K_(L)positively correlated with NUEg.These findings indicate that increasing planting density under reduced N input could maintain rice yield while enhancing resource use efficiency through regulation of canopy light and N distribution.
基金financially supported by the National Science & Technology Fundamental Resources Investigation Project of China (2021FY100501)the Youth Innovation of Chinese Academy of Agricultural Sciences (Y2023QC16)。
文摘Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.
基金funded by the Science and Technology Programme of Inner Mongolia Autonomous Region(Grant No.:2023YFDZ0026 and 2024KYPT0003)the 2024 Postgraduate Research and Innovation Programme of Inner Mongolia Agricultural University。
文摘Changes in the soil environment induced by major global changes in climate are affecting carbon emissions in cold-temperate coniferous forests.A randomized block experiment simulating warming,rainfall increase and nitrogen addition in a Larix gmelinii forest was carried out to study the effects on soil carbon,nitrogen,and CO_(2)flux during the thawing,growing,and freezing periods.Our study found that warming(0-2.0℃)increased soil organic carbon(SOC)and total nitrogen(STN),dissolved organic carbon(DOC)and dissolved organic nitrogen(DON),and microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN).Warming played a direct role in regulating soil CO_(2)emissions,stimulated microbial and plant root respiration and soil CO_(2)flux rapidly increased.Rainfall increase initially increased soil carbon and nitrogen,but a 30%increase in mean annual rainfall caused losses of SOC,STN,DOC,and DON,while MBC and MBN accumulated.Soil CO_(2)emissions were regulated by MBC after an increase in rainfall,excess moisture inhibited microbial activity,and soil CO_(2)flux showed a trend of R2(20%rainfall increase)>R1(10%rainfall increase)>CK(control)>R3(30%rainfall increase).The addition of nitrogen increased SOC,STN,DOC,DON,MBC and MBN.Soil CO_(2)flux progressively decreased with nitrogen inputs(2.5,5.0 and 10.0 g m^(-2)a^(-1)),as more N intensified plant-microbe competition.Nitrogen addition indirectly regulated soil CO_(2)emissions by altering SOC and STN,with MBC and MBN acting as secondary regulators.The results highlight the role of cold-temperate coniferous forest soils in predicting carbon-climate feedback in high-latitude forest permafrost regions.
基金supported by the Natural Science Foundation of China(Grant Nos.T2325013,52288102,52090024,12034009,12474004,and 12304036)the National Key R&D Program of China Grant No.2023YFA1610000+1 种基金the Fundamental Research Funds for the Central Universitiesthe Program for Jilin University and Sun Yat-sen University.
文摘We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.
