Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially ...Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially for small and medium-sized coal-fired boilers and furnaces.Herein,phosphorus sludge,an industrial waste from the production process of yellow phosphorus,has been developed to simultaneously eliminate SO_(2)and NO_(x)from coal-fired flue gas.The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95%can be achieved at a low temperature of 55℃.Further,the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process.The efficient removal of SO_(2)is attributed to the abundance of iron(Fe^(3+))and manganese(Mn^(2+))in the absorbent.SO_(2)can be rapidly catalyzed and converted to SO_(4)^(2-)by them.The key to NOx removal is the oxidation of NO toward watersoluble high-valent nitrogen oxides by oxidizing reactive substances induced via yellow phosphorus,which are then absorbed by water and converted to NO_(3)^(-).Meanwhile,yellow phosphorus is oxidized to phosphoric acid(H_(3)PO_(4)).The spent absorption slurry can be reused through wet process phosphoric acid production,as it contains sulfuric acid(H_(2)SO_(4)),nitric acid(HNO_(3)),and H_(3)PO_(4).Accordingly,this is a technology with broad application prospects.展开更多
Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,cau...Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,causing secondary pollution of the river water.In this study,laboratory simulation experiments were conducted initially to investigate the release of nitrogen and phosphorus from river sediments in Urumqi City and the surrounding areas in Xinjiang Uygur Autonomous Region of China and determine the factors that influence their release.The results of this study showed significant short-term differences in nitrogen and phosphorus release characteristics from sediments at different sampling points.The proposed secondary kinetics model(i.e.,pseudo-second-order kinetics model)better fitted the release process of sediment nitrogen and phosphorus.The release of nitrogen and phosphorus from sediments is a complex process driven by multiple factors,therefore,we tested the influence of three factors(pH,temperature,and disturbance intensity)on the release of nitrogen and phosphorus from sediments in this study.The most amount of nitrate nitrogen(NO_(3)^(–)-N)was released under neutral conditions,while the most significant release of ammonia nitrogen(NH_(4)^(+)-N)occurred under acidic and alkaline conditions.The release of nitrite nitrogen(NO_(2)^(-)-N)was less affected by pH.The dissolved total phosphorus(DTP)released significantly in the alkaline water environment,while the release of dissolved organic phosphorus(DOP)was more significant in acidic water.The release amount of soluble reactive phosphorus(SRP)increased with an increase in pH.The sediments released nitrogen and phosphorus at higher temperatures,particularly NH_(4)^(+)-N,NO_(3)^(–)-N,and SRP.The highest amount of DOP was released at 15.0℃.An increase in disturbance intensity exacerbated the release of nitrogen and phosphorus from sediments.NH_(4)^(+)-N,DTP,and SRP levels increased linearly with the intensity of disturbance,while NO_(3)^(–)-N and NO_(2)^(–)-N were more stable.This study provides valuable information for protecting and restoring the water environment in arid areas and has significant practical reference value.展开更多
Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivi...Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivity in tropical forests throughout the 21st century due to CO_(2)fertilization.However,phosphorus(P)liaitations on vegetation photosynthesis and productivity could significantly reduce the CO_(2)fertilization effect.Here,we used a carbon-nitrogen-phosphorus coupled model(Dynamic Land Ecosystem Model;DLEM-CNP)with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests during1860-2018.Our model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem productivity.We further compared the simulations from DLEM-CNP,DLEM-CN,and DLEMC and the results showed that the inclusion of P processes reduced the CO_(2)fertilization effect on gross primary production(GPP)by 25%and 45%,and net ecosystem production(NEP)by 28%and 41%,respectively,relative to CN-only and C-on ly models.From the 1860s to the 2010s,the DLEM-CNP estimated that in tropical forests GPP increased by 17%,plant respiration(Ra)increased by 18%,ecosystem respiration(Rh)increased by 13%,NEP increased by 121%per unit area,respectively.Additionally,factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO_(2) fertilization effect had been offset by 135%due to deforestation from the 1860s to the 2010s.Our study highlights the importance of P limitation on the C cycle and the weakened CO_(2)fertilization effect resulting from P limitation in tropical forests.展开更多
The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal percept...The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.展开更多
Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the ba...Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the bacterial community modifications are poorly understood. Here, six soybean(Glycine max) genotypes with differences in P efficiency were cultivated in acidic soils with long-term sufficient or deficient P-fertilizer treatments. The acid phosphatase(AcP) activities, organic-P concentrations and associated bacterial community compositions were determined in bulk and rhizosphere soils. The results showed that both soybean plant P content and the soil AcP activity were negatively correlated with soil organic-P concentration in P-deficient acidic soils. Soil P-availability affected the ɑ-diversity of bacteria in both bulk and rhizosphere soils. However, soybean had a stronger effect on the bacterial community composition, as reflected by the similar biomarker bacteria in the rhizosphere soils in both P-treatments. The relative abundance of biomarker bacteria Proteobacteria was strongly correlated with soil organic-P concentration and AcP activity in low-P treatments. Further high-throughput sequencing of the phoC gene revealed an obvious shift in Proteobacteria groups between bulk soils and rhizosphere soils, which was emphasized by the higher relative abundances of Cupriavidus and Klebsiella, and lower relative abundance of Xanthomonas in rhizosphere soils. Among them, Cupriavidus was the dominant phoC bacterial genus, and it was negatively correlated with the soil organic-P concentration. These findings suggest that soybean growth relies on organic-P mineralization in P-deficient acidic soils, which might be partially achieved by recruiting specific phoCharboring bacteria, such as Cupriavidus.展开更多
We used field experimental data to evaluate the ability of the agricultural production system model (APSIM) to simulate soil P availability,maize biomass and grain yield in response to P fertilizer applications on a f...We used field experimental data to evaluate the ability of the agricultural production system model (APSIM) to simulate soil P availability,maize biomass and grain yield in response to P fertilizer applications on a fluvo-aquic soil in the North China Plain.Crop and soil data from a 2-year experiment with three P fertilizer application rates(0,75 and 300 kg P_(2)O_(5) ha^(–1)) were used to calibrate the model.Sensitivity analysis was carried out to investigate the influence of APSIM SoilP parameters on the simulated P availability in soil and maize growth.Crop and soil P parameters were then derived by matching or relating the simulation results to observed crop biomass,yield,P uptake and Olsen-P in soil.The re-parameterized model was further validated against 2 years of independent data at the same sites.The re-parameterized model enabled good simulation of the maize leaf area index (LAI),biomass,grain yield,P uptake,and grain P content in response to different levels of P additions against both the calibration and validation datasets.Our results showed that APSIM needs to be re-parameterized for simulation of maize LAI dynamics through modification of leaf size curve and a reduction in the rate of leaf senescence for modern staygreen maize cultivars in China.The P concentration limits (maximum and minimum P concentrations in organs)at different stages also need to be adjusted.Our results further showed a curvilinear relationship between the measured Olsen-P concentration and simulated labile P content,which could facilitate the initialization of APSIM P pools in the NCP with Olsen-P measurements in future studies.It remains difficult to parameterize the APSIM SoilP module due to the conceptual nature of the pools and simplified conceptualization of key P transformation processes.A fundamental understanding still needs to be developed for modelling and predicting the fate of applied P fertilizers in soils with contrasting physical and chemical characteristics.展开更多
Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types withi...Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types within the canopy are poorly quantified.In this study,the seasonality of leaf chlorophyll,nitrogen(N),and phosphorus(P)were quantified vertically along the canopy of four major tree species and two types of herbs in a temperate deciduous forest.The role of shade tolerance in shaping the seasonal variation and vertical differentiation was examined.During the entire season,chlorophyll content showed a distinct asymmetric unimodal pattern for all species,with greater chlorophyll levels in autumn than in spring,and the timing of peak chlorophyll per leaf area gradually decreased as shade tolerance increased.Chlorophyll a:b ratios gradually decreased with increasing shade tolerance.Leaf N and P contents sharply declined during leaf expansion,remained steady in the mature stage and decreased again during leaf senescence.Over the seasons,the lower canopy layer had significantly higher chlorophyll per leaf mass but not chlorophyll per leaf area than the upper canopy layer regardless of degree of shade tolerance.However,N and P per leaf area of intermediate shade-tolerant and fully shade-tolerant tree species were significantly higher in the upper canopy than in the lower.Seasonal variations in N:P ratios suggest changes in N or P limitation.These findings indicate that shade tolerance is a key feature shaping inter-specific differences in leaf chlorophyll,N,and P contents as well as their seasonality in temperate deciduous forests,which have significant implications for modeling leaf photosynthesis and ecosystem production.展开更多
Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective appro...Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective approach for achieving high maize yields.However,the low mobility of P in soils and the scarcity of natural P resources have hindered the development of methods that can simultaneously optimize P use and mitigate the P-related environmental footprint at high plant densities.In this study,meta-analysis and substance flow analysis were conducted to evaluate the effects of different types of mineral P fertilizer on maize yield at varying plant densities and assess the flow of P from rock phosphate mining to P fertilizer use for maize production in China.A significantly higher yield was obtained at higher plant densities than at lower plant densities.The application of single superphosphate,triple super-phosphate,and calcium magnesium phosphate at high plant densities resulted in higher yields and a smaller environmental footprint than the application of diammonium phosphate and monoammonium phosphate.Our scenario analyses suggest that combining the optimal P type and application rate with a high plant density could increase maize yield by 22%.Further,the P resource use efficiency throughout the P supply chain increased by 39%,whereas the P-related environmental footprint decreased by 33%.Thus,simultaneously optimizing the P type and application rate at high plant densities achieved multiple objectives during maize production,indicating that combining P management with cropping techniques is a practical approach to sustainable maize production.These findings offer strategic,synergistic options for achieving sustainable agricultural development.展开更多
Phosphorus(P) levels alter the allelopathic activity of rice seedlings against lettuce seeds. In this study, we investigated the effect of P deficiency on the allelopathic potential of non-pigmented and pigmented rice...Phosphorus(P) levels alter the allelopathic activity of rice seedlings against lettuce seeds. In this study, we investigated the effect of P deficiency on the allelopathic potential of non-pigmented and pigmented rice varieties. Rice seedlings of the white variety Khao Dawk Mali(KDML105, non-pigmented) and the black varieties Jao Hom Nin(JHN, pigmented) and Riceberry(RB, pigmented) were cultivated under high P(HP) and low P(LP) conditions. Morphological and metabolic responses to P deficiency were investigated. P deficiency inhibited shoot growth but promoted root growth of rice seedlings in all three varieties. Moreover, P deficiency led to decreased cytosolic phosphate(Pi) and total P concentrations in both shoot and root tissues. The subsequent reduction in internal P concentration enhanced the accumulation of phenolic compounds in both shoot and root tissues of the seedlings. Subsequently, allelopathy-based inter-and intra-specific interactions were assessed using water extracts from seedlings of the three varieties grown under HP and LP conditions. These extracts were tested on seeds of lettuce, the weed Dactyloctenium aegyptium, and the same rice variety. The shoot and root extracts from P-deficient seedlings reduced the germination of all recipient plants. Specifically, the shoot extract from P-deficient KDML105 seedlings reduced the germination index(GI) of lettuce seeds to 1%, while those from P-deficient RB and JHN seedlings produced GIs of 32% and 42%, respectively. However, when rice seeds were exposed to their own LP shoot and root extracts, their GIs increased up to 4-fold, compared with the HP extracts. Additionally, the shoot extracts from P-deficient plants also stimulated the germination of D. aegyptium by about 2–3-fold, whereas the root extracts did not have this effect. Therefore, P starvation led to the accumulation and exudation of phenolics in the shoots and roots of rice seedlings, altering their allelopathic activities. To adapt to P deficiency, rice seedlings potentially release signaling chemicals to suppress nearby competing species while simultaneously promoting their own germination and growth.展开更多
We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density...We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density functional theory.The results show that there are band crossings in the Z-L(armchair)direction.展开更多
Phosphorus is a limiting factor in agriculture due to restricted availability in soil and low utilization efficiency of crops.The identification of superior haplotypes of key genes responsible for low-phosphate(Pi)tol...Phosphorus is a limiting factor in agriculture due to restricted availability in soil and low utilization efficiency of crops.The identification of superior haplotypes of key genes responsible for low-phosphate(Pi)tolerance and their natural variation is important for molecular breeding.In this study,we conducted genome-wide association studies on low-phosphate tolerance coefficients using 152 maize inbred lines,and identified a significant association between SNPs on chromosome 7 and a low-phosphate tolerance coefficient.ZmGRF10 was identified as a candidate gene involved in adaptation of maize to Pi starvation.Expression of ZmGRF10 is induced by Pi starvation.A mutation in ZmGRF10 alleviated Pi starvation stress.RNA-seq analyses revealed significant upregulation of genes encoding various phosphatases in the zmgrf10-1 mutant,suggesting that ZmGRF10 negatively regulates expression of these genes,thereby affecting low-Pi tolerance by suppressing phosphorus remobilization.A superior haplotype with variations in the promoter region exhibited lower transcription activity of ZmGRF10.Our study unveiled a novel gene contributing to tolerance to low-Pi availability with potential to benefit molecular breeding for high Pi utilization.展开更多
The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the settin...The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect,but for PBG shows a poor retarding effect.Furthermore,the deterioration reason of the retarding effect of protein retarder on PBG was investigated by measuring the pH value and the retarder concentration of the liquid phase from vacuum filtration of PBG slurry at different hydration time,and the measure to improve the retarding effect of protein retarding on PBG was suggested.The pH value of PBG slurry(<5.0)is lower than that of DBG slurry(7.8-8.5).After hydration for 5 min,the concentration of retarder in liquid phase of DBG slurry gradually decreases,but in liquid phase of PBG slurry continually increases,which results in the worse retarding effect of protein retarder on PBG.The liquid phase pH value of PBG slurry can be adjusted higher by sodium silicate,which is beneficial to improvement in the retarding effect of the retarder.By adding 1.0%of sodium silicate,the initial setting time of PBG was efficiently prolonged from 17 to 210 min,but little effect on the absolute dry flexural strength was observed.展开更多
The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted ...The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted during the summer of 2022 in the Changjiang River(Yangtze River) Estuary(CJE) and its adjacent waters.The settling column method was employed to measure the sinking velocity(SV) of different size fractions of phytoplankton at the surface of the sea and to analyze their environmental control mechanisms.The findings reveal significant spatial variation in phytoplankton SV(-0.55-2.41 m/d) within the CJE.High-speed sinking was predominantly observed in phosphate-depleted regions beyond the CJE front.At the same time,an upward trend was more commonly observed in the phosphate-rich regions near the CJE mouth.The SV ranges for different sizefractionated phytoplankton,including micro-(>20 μm),nano-(2-20 μm),and picophytoplankton(0.7-2 μm),were-0.50-4.74 m/d,-1.04-1.59 m/d,and-1.24-1.65 m/d,respectively.Correlation analysis revealed a significant negative correlation between SV and dissolved inorganic phosphorus(DIP),implying that the influence of DIP contributes to SV.The variations in phytoplankton alkaline phosphatase activity suggested a significant increase in SV across all size fractions in the event of phosphorus limitation.Phytoplankton communities with limited photo synthetic capacity(maximum photochemical efficience,Fv/Fm <0.3) were found to have higher SV than that of communities with strong capacity,suggesting a link between sinking and alterations in physiological conditions due to phosphate depletion.The findings from the in situ phosphate enrichment experiments confirmed a marked decrease in SV following phosphate supplementation.These findings suggest that phosphorus limitation is the primary driver of elevated SV in the CJE.This study enhances the comprehension of the potential mechanisms underlying hypoxic zone formation in the CJE,providing novel insights into how nearshore eutrophication influences organic carbon migration.展开更多
The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification ...The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification technique with the aims to reveal the effects of phosphorus content on interfacial wettability,deposited film,and interfacial heat transfer behavior.Results showed that when the phosphorus content increased from 0.014wt%to 0.406wt%,the mushy zone enlarged,the complete solidification temperature delayed from1518.3 to 1459.4℃,the final contact angle decreased from 118.4°to 102.8°,indicating improved interfacial contact,and the maximum heat flux increased from 6.9 to 9.2 MW/m2.Increasing the phosphorus content from 0.081wt%to 0.406wt%also accelerated the film deposition rate from 1.57 to 1.73μm per test,resulting in a thickened naturally deposited film with increased thermal resistance that advanced the transition point of heat transfer from the fifth experiment to the third experiment.展开更多
Black phosphorus nanotubes(BPNTs)may have good properties and potential applications.Determining thevibration property of BPNTs is essential for gaining insight into the mechanical behaviour of BPNTs and designingopti...Black phosphorus nanotubes(BPNTs)may have good properties and potential applications.Determining thevibration property of BPNTs is essential for gaining insight into the mechanical behaviour of BPNTs and designingoptimized nanodevices.In this paper,the mechanical behaviour and vibration property of BPNTs are studied viaorthotropic cylindrical shell model and molecular dynamics(MD)simulation.The vibration frequencies of twochiral BPNTs are analysed systematically.According to the results of MD calculations,it is revealed that thenatural frequencies of two BPNTs with approximately equal sizes are unequal at each order,and that the naturalfrequencies of armchair BPNTs are higher than those of zigzag BPNTs.In addition,an armchair BPNTs witha stable structure is considered as the object of research,and the vibration frequencies of BPNTs of differentsizes are analysed.When comparing the MD results,it is found that both the isotropic cylindrical shell modeland orthotropic cylindrical shell model can better predict the thermal vibration of the lower order modes of thelonger BPNTs better.However,for the vibration of shorter and thinner BPNTs,the prediction of the orthotropiccylindrical shell model is obviously superior to the isotropic shell model,thereby further proving the validity ofthe shell model that considers orthotropic for BPNTs.展开更多
The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.Howev...The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement.展开更多
Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutr...Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.展开更多
The effects of different contents of a MgO expansive agent and phosphorus slag on the mechanical properties,shrinkage behavior,and the heat of hydration of concrete were studied.The slump flow,setting time,dry shrinka...The effects of different contents of a MgO expansive agent and phosphorus slag on the mechanical properties,shrinkage behavior,and the heat of hydration of concrete were studied.The slump flow,setting time,dry shrinkage,and hydration heat were used as sensitive parameters to assess the response of the considered specimens.As shown by the results,in general,with an increase in the phosphorus slag content,the hydration heat of concrete decreases for all ages,but the early strength displays a downward trend and the dry shrinkage rate increases.The 90-d strength and dry shrinkage of concrete could be improved with a phosphorus residue content between 0%-20%,with the best performances in terms of mechanical properties and shrinkage characteristics being achieved for a content of 20 kg/m^(3).On the basis of these results,it can be concluded that appropriate amounts of phosphorus slag and MgO expansive agent can be used to improve the compressive strength of concrete in the later stage by reducing the hydration heat and dry shrinkage rate,respectively.展开更多
Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key ...Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key role in P absorption.To investigate the genetic variability of RMT under low P availability,we dissected the genetic structure of RMTs by genome-wide association studies(GWAS),linkage mapping and candidate gene association studies(CGAS).A total of 52 suggestive loci were associated with RMTs under P stress conditions in 405 oilseed rape accessions.The purple acid phosphatase gene BnPAP17 was found to control the lateral root number(LRN)and root dry weight(RDW)under low P stress.The expression of BnPAP17 was increased in shoot tissue in P-efficient cultivars compared to root tissue and P-inefficient cultivars in response to low P stress.Moreover,the haplotype of BnPAP17^(Hap3)was detected for the selective breeding of P efficiency in oilseed rape.Over-expression of the BnPAP17^(Hap3)could promote the shoot and root growth with enhanced tolerance to low P stress and organic phosphorus(Po)utilization in oilseed rape.Collectively,these findings increase our understanding of the mechanisms underlying BnPAP17-mediated low P stress tolerance in oilseed rape.展开更多
[Objectives]To study the phosphorus removal performance of phosphate accumulating organisms(PAOs).[Methods]Activated sludge from domestic sewage treatment plant was used as the strain source,and phosphate accumulating...[Objectives]To study the phosphorus removal performance of phosphate accumulating organisms(PAOs).[Methods]Activated sludge from domestic sewage treatment plant was used as the strain source,and phosphate accumulating organisms were screened by plate streaking method and dilution coating plate method.Six kinds of excellent phosphate accumulating organisms were obtained by metachromatic granule staining experiment,total phosphorus experiment and simulated sewage phosphorus removal experiment to assist the observation of bac-terial morphology and experiment of phosphorus removal capacity.In addition,the influencing factors of phosphorus removal capacity(nitrogen source,trace metal ions)were analyzed.[Results]In the case of simulated sewage,the phosphorus removal rate of strain b was the highest,reaching 66.25%,while the phosphorus removal rate of strain e and f was about 10%lower than that of the phosphorus uptake experiment.[Conclusions]This study is expected to provide a theoretical reference for the gradual optimization of the screening method of phosphorus re-moval bacteria in domestic sewage treatment.展开更多
基金The National Natural Science Foundation of China (22068019)Yunnan Major Scientific and Technological Projects (202202AG050001)
文摘Developing low-cost and green simultaneous desulfurization and denitrification technologies is of great significance for sulfur dioxide(SO_(2))and nitrogen oxide(NO_(x))emission control at low temperatures,especially for small and medium-sized coal-fired boilers and furnaces.Herein,phosphorus sludge,an industrial waste from the production process of yellow phosphorus,has been developed to simultaneously eliminate SO_(2)and NO_(x)from coal-fired flue gas.The key factors affecting the experimental results indicate that desulfurization and denitrification efficiency of over 95%can be achieved at a low temperature of 55℃.Further,the absorption mechanism was investigated by characterizing the solid and liquid phases of the phosphorus sludge during the absorption process.The efficient removal of SO_(2)is attributed to the abundance of iron(Fe^(3+))and manganese(Mn^(2+))in the absorbent.SO_(2)can be rapidly catalyzed and converted to SO_(4)^(2-)by them.The key to NOx removal is the oxidation of NO toward watersoluble high-valent nitrogen oxides by oxidizing reactive substances induced via yellow phosphorus,which are then absorbed by water and converted to NO_(3)^(-).Meanwhile,yellow phosphorus is oxidized to phosphoric acid(H_(3)PO_(4)).The spent absorption slurry can be reused through wet process phosphoric acid production,as it contains sulfuric acid(H_(2)SO_(4)),nitric acid(HNO_(3)),and H_(3)PO_(4).Accordingly,this is a technology with broad application prospects.
基金the Xinjiang Science and Technology Support Project Plan(2022E02026)the Xinjiang Agricultural University Graduate Research and Innovation Programme(XJAUGRI2023049).
文摘Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,causing secondary pollution of the river water.In this study,laboratory simulation experiments were conducted initially to investigate the release of nitrogen and phosphorus from river sediments in Urumqi City and the surrounding areas in Xinjiang Uygur Autonomous Region of China and determine the factors that influence their release.The results of this study showed significant short-term differences in nitrogen and phosphorus release characteristics from sediments at different sampling points.The proposed secondary kinetics model(i.e.,pseudo-second-order kinetics model)better fitted the release process of sediment nitrogen and phosphorus.The release of nitrogen and phosphorus from sediments is a complex process driven by multiple factors,therefore,we tested the influence of three factors(pH,temperature,and disturbance intensity)on the release of nitrogen and phosphorus from sediments in this study.The most amount of nitrate nitrogen(NO_(3)^(–)-N)was released under neutral conditions,while the most significant release of ammonia nitrogen(NH_(4)^(+)-N)occurred under acidic and alkaline conditions.The release of nitrite nitrogen(NO_(2)^(-)-N)was less affected by pH.The dissolved total phosphorus(DTP)released significantly in the alkaline water environment,while the release of dissolved organic phosphorus(DOP)was more significant in acidic water.The release amount of soluble reactive phosphorus(SRP)increased with an increase in pH.The sediments released nitrogen and phosphorus at higher temperatures,particularly NH_(4)^(+)-N,NO_(3)^(–)-N,and SRP.The highest amount of DOP was released at 15.0℃.An increase in disturbance intensity exacerbated the release of nitrogen and phosphorus from sediments.NH_(4)^(+)-N,DTP,and SRP levels increased linearly with the intensity of disturbance,while NO_(3)^(–)-N and NO_(2)^(–)-N were more stable.This study provides valuable information for protecting and restoring the water environment in arid areas and has significant practical reference value.
基金partially supported by the US National Science Foundation(1903722,1243232)。
文摘Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivity in tropical forests throughout the 21st century due to CO_(2)fertilization.However,phosphorus(P)liaitations on vegetation photosynthesis and productivity could significantly reduce the CO_(2)fertilization effect.Here,we used a carbon-nitrogen-phosphorus coupled model(Dynamic Land Ecosystem Model;DLEM-CNP)with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests during1860-2018.Our model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem productivity.We further compared the simulations from DLEM-CNP,DLEM-CN,and DLEMC and the results showed that the inclusion of P processes reduced the CO_(2)fertilization effect on gross primary production(GPP)by 25%and 45%,and net ecosystem production(NEP)by 28%and 41%,respectively,relative to CN-only and C-on ly models.From the 1860s to the 2010s,the DLEM-CNP estimated that in tropical forests GPP increased by 17%,plant respiration(Ra)increased by 18%,ecosystem respiration(Rh)increased by 13%,NEP increased by 121%per unit area,respectively.Additionally,factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO_(2) fertilization effect had been offset by 135%due to deforestation from the 1860s to the 2010s.Our study highlights the importance of P limitation on the C cycle and the weakened CO_(2)fertilization effect resulting from P limitation in tropical forests.
基金supported by National Natural Science Foundation of China(No.51902250).
文摘The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.
基金This work was supported by grants from the National Key Research and Development Program of China(2021YFF1000500)the Open Competition Program of Ten Major Directions of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province,China(2022SDZG07)+3 种基金the Key Areas Research and Development Programs of Guangdong Province,China(2022B0202060005)the STICGrantof China(SGDX20210823103535007)the Major Program of Guangdong Basic and Applied Research,China(2019B030302006)the Natural Science Foundation of Guangdong Province,China(2021A1515010826and 2020A1515110261).
文摘Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the bacterial community modifications are poorly understood. Here, six soybean(Glycine max) genotypes with differences in P efficiency were cultivated in acidic soils with long-term sufficient or deficient P-fertilizer treatments. The acid phosphatase(AcP) activities, organic-P concentrations and associated bacterial community compositions were determined in bulk and rhizosphere soils. The results showed that both soybean plant P content and the soil AcP activity were negatively correlated with soil organic-P concentration in P-deficient acidic soils. Soil P-availability affected the ɑ-diversity of bacteria in both bulk and rhizosphere soils. However, soybean had a stronger effect on the bacterial community composition, as reflected by the similar biomarker bacteria in the rhizosphere soils in both P-treatments. The relative abundance of biomarker bacteria Proteobacteria was strongly correlated with soil organic-P concentration and AcP activity in low-P treatments. Further high-throughput sequencing of the phoC gene revealed an obvious shift in Proteobacteria groups between bulk soils and rhizosphere soils, which was emphasized by the higher relative abundances of Cupriavidus and Klebsiella, and lower relative abundance of Xanthomonas in rhizosphere soils. Among them, Cupriavidus was the dominant phoC bacterial genus, and it was negatively correlated with the soil organic-P concentration. These findings suggest that soybean growth relies on organic-P mineralization in P-deficient acidic soils, which might be partially achieved by recruiting specific phoCharboring bacteria, such as Cupriavidus.
基金funded by the National Natural Science Program of China(2022YFD1900300)the China Scholarship Council(CSC)through the CSC-CSIRO(Commonwealth Scientific and Industrial Research Organisation)Joint Ph D Program,the Zhumadian Major Scientific and Technological Innovation Project,China(170109564016)the Huanghuai University Scientific Research Foundation,China(502310020017)。
文摘We used field experimental data to evaluate the ability of the agricultural production system model (APSIM) to simulate soil P availability,maize biomass and grain yield in response to P fertilizer applications on a fluvo-aquic soil in the North China Plain.Crop and soil data from a 2-year experiment with three P fertilizer application rates(0,75 and 300 kg P_(2)O_(5) ha^(–1)) were used to calibrate the model.Sensitivity analysis was carried out to investigate the influence of APSIM SoilP parameters on the simulated P availability in soil and maize growth.Crop and soil P parameters were then derived by matching or relating the simulation results to observed crop biomass,yield,P uptake and Olsen-P in soil.The re-parameterized model was further validated against 2 years of independent data at the same sites.The re-parameterized model enabled good simulation of the maize leaf area index (LAI),biomass,grain yield,P uptake,and grain P content in response to different levels of P additions against both the calibration and validation datasets.Our results showed that APSIM needs to be re-parameterized for simulation of maize LAI dynamics through modification of leaf size curve and a reduction in the rate of leaf senescence for modern staygreen maize cultivars in China.The P concentration limits (maximum and minimum P concentrations in organs)at different stages also need to be adjusted.Our results further showed a curvilinear relationship between the measured Olsen-P concentration and simulated labile P content,which could facilitate the initialization of APSIM P pools in the NCP with Olsen-P measurements in future studies.It remains difficult to parameterize the APSIM SoilP module due to the conceptual nature of the pools and simplified conceptualization of key P transformation processes.A fundamental understanding still needs to be developed for modelling and predicting the fate of applied P fertilizers in soils with contrasting physical and chemical characteristics.
基金This work was supported by the National Natural Science Foundation of China(32171765).
文摘Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types within the canopy are poorly quantified.In this study,the seasonality of leaf chlorophyll,nitrogen(N),and phosphorus(P)were quantified vertically along the canopy of four major tree species and two types of herbs in a temperate deciduous forest.The role of shade tolerance in shaping the seasonal variation and vertical differentiation was examined.During the entire season,chlorophyll content showed a distinct asymmetric unimodal pattern for all species,with greater chlorophyll levels in autumn than in spring,and the timing of peak chlorophyll per leaf area gradually decreased as shade tolerance increased.Chlorophyll a:b ratios gradually decreased with increasing shade tolerance.Leaf N and P contents sharply declined during leaf expansion,remained steady in the mature stage and decreased again during leaf senescence.Over the seasons,the lower canopy layer had significantly higher chlorophyll per leaf mass but not chlorophyll per leaf area than the upper canopy layer regardless of degree of shade tolerance.However,N and P per leaf area of intermediate shade-tolerant and fully shade-tolerant tree species were significantly higher in the upper canopy than in the lower.Seasonal variations in N:P ratios suggest changes in N or P limitation.These findings indicate that shade tolerance is a key feature shaping inter-specific differences in leaf chlorophyll,N,and P contents as well as their seasonality in temperate deciduous forests,which have significant implications for modeling leaf photosynthesis and ecosystem production.
基金supported by the National Natural Science Foundation of China(32301453 and 3272675)the China Postdoctoral Science Foundation(2023M730682)。
文摘Achieving high maize yields and efficient phosphorus(P)use with limited environmental impacts is one of the greatest challenges in sustainable maize production.Increasing plant density is considered an effective approach for achieving high maize yields.However,the low mobility of P in soils and the scarcity of natural P resources have hindered the development of methods that can simultaneously optimize P use and mitigate the P-related environmental footprint at high plant densities.In this study,meta-analysis and substance flow analysis were conducted to evaluate the effects of different types of mineral P fertilizer on maize yield at varying plant densities and assess the flow of P from rock phosphate mining to P fertilizer use for maize production in China.A significantly higher yield was obtained at higher plant densities than at lower plant densities.The application of single superphosphate,triple super-phosphate,and calcium magnesium phosphate at high plant densities resulted in higher yields and a smaller environmental footprint than the application of diammonium phosphate and monoammonium phosphate.Our scenario analyses suggest that combining the optimal P type and application rate with a high plant density could increase maize yield by 22%.Further,the P resource use efficiency throughout the P supply chain increased by 39%,whereas the P-related environmental footprint decreased by 33%.Thus,simultaneously optimizing the P type and application rate at high plant densities achieved multiple objectives during maize production,indicating that combining P management with cropping techniques is a practical approach to sustainable maize production.These findings offer strategic,synergistic options for achieving sustainable agricultural development.
基金supported by the National Science Research and Innovation Fund and Prince of Songkla University, Thailand (Grant No. SCI6601035S)a Graduate Fellowship from the Faculty of Science, Prince of Songkla University, Thailand (Grant No. 1-2565-02-017)。
文摘Phosphorus(P) levels alter the allelopathic activity of rice seedlings against lettuce seeds. In this study, we investigated the effect of P deficiency on the allelopathic potential of non-pigmented and pigmented rice varieties. Rice seedlings of the white variety Khao Dawk Mali(KDML105, non-pigmented) and the black varieties Jao Hom Nin(JHN, pigmented) and Riceberry(RB, pigmented) were cultivated under high P(HP) and low P(LP) conditions. Morphological and metabolic responses to P deficiency were investigated. P deficiency inhibited shoot growth but promoted root growth of rice seedlings in all three varieties. Moreover, P deficiency led to decreased cytosolic phosphate(Pi) and total P concentrations in both shoot and root tissues. The subsequent reduction in internal P concentration enhanced the accumulation of phenolic compounds in both shoot and root tissues of the seedlings. Subsequently, allelopathy-based inter-and intra-specific interactions were assessed using water extracts from seedlings of the three varieties grown under HP and LP conditions. These extracts were tested on seeds of lettuce, the weed Dactyloctenium aegyptium, and the same rice variety. The shoot and root extracts from P-deficient seedlings reduced the germination of all recipient plants. Specifically, the shoot extract from P-deficient KDML105 seedlings reduced the germination index(GI) of lettuce seeds to 1%, while those from P-deficient RB and JHN seedlings produced GIs of 32% and 42%, respectively. However, when rice seeds were exposed to their own LP shoot and root extracts, their GIs increased up to 4-fold, compared with the HP extracts. Additionally, the shoot extracts from P-deficient plants also stimulated the germination of D. aegyptium by about 2–3-fold, whereas the root extracts did not have this effect. Therefore, P starvation led to the accumulation and exudation of phenolics in the shoots and roots of rice seedlings, altering their allelopathic activities. To adapt to P deficiency, rice seedlings potentially release signaling chemicals to suppress nearby competing species while simultaneously promoting their own germination and growth.
基金supported by the National Natural Science Foundation of China(Grant Nos.12104216,12241403,and 61974061)the National Key R&D Program of China(Grant No.2021YFB3601600)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20140054)。
文摘We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density functional theory.The results show that there are band crossings in the Z-L(armchair)direction.
基金funded by the National Key Research and Development Program of China (2022YFD1201700)the National Natural Science Foundation of China (32272130)the Jiangsu Collaborative Innovation Center for Modern Crop Production for their support。
文摘Phosphorus is a limiting factor in agriculture due to restricted availability in soil and low utilization efficiency of crops.The identification of superior haplotypes of key genes responsible for low-phosphate(Pi)tolerance and their natural variation is important for molecular breeding.In this study,we conducted genome-wide association studies on low-phosphate tolerance coefficients using 152 maize inbred lines,and identified a significant association between SNPs on chromosome 7 and a low-phosphate tolerance coefficient.ZmGRF10 was identified as a candidate gene involved in adaptation of maize to Pi starvation.Expression of ZmGRF10 is induced by Pi starvation.A mutation in ZmGRF10 alleviated Pi starvation stress.RNA-seq analyses revealed significant upregulation of genes encoding various phosphatases in the zmgrf10-1 mutant,suggesting that ZmGRF10 negatively regulates expression of these genes,thereby affecting low-Pi tolerance by suppressing phosphorus remobilization.A superior haplotype with variations in the promoter region exhibited lower transcription activity of ZmGRF10.Our study unveiled a novel gene contributing to tolerance to low-Pi availability with potential to benefit molecular breeding for high Pi utilization.
文摘The retarding effect of protein retarder on phosphorus building gypsum(PBG)and desulfurization building gypsum(DBG)was investigated,and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect,but for PBG shows a poor retarding effect.Furthermore,the deterioration reason of the retarding effect of protein retarder on PBG was investigated by measuring the pH value and the retarder concentration of the liquid phase from vacuum filtration of PBG slurry at different hydration time,and the measure to improve the retarding effect of protein retarding on PBG was suggested.The pH value of PBG slurry(<5.0)is lower than that of DBG slurry(7.8-8.5).After hydration for 5 min,the concentration of retarder in liquid phase of DBG slurry gradually decreases,but in liquid phase of PBG slurry continually increases,which results in the worse retarding effect of protein retarder on PBG.The liquid phase pH value of PBG slurry can be adjusted higher by sodium silicate,which is beneficial to improvement in the retarding effect of the retarder.By adding 1.0%of sodium silicate,the initial setting time of PBG was efficiently prolonged from 17 to 210 min,but little effect on the absolute dry flexural strength was observed.
基金The National Programme on Global Change and Air-Sea Interaction (PhaseⅡ)—Hypoxia and Acidification Monitoring and Warning Project in the CE under contract No.GASI-01-CJKthe Science Foundation of Donghai Laboratory under contract No.DH-2022KF0215+3 种基金the Oceanic Interdisciplinary Program of Shanghai Jiao Tong UniversityScientific Research Fund of the Second Institute of Oceanography,MNR under contract No.SL2022ZD207the National Key R&D Program of China under contract No.2021YFC3101702the Long-term Observation and Research Plan in the Changjiang Estuary and Adjacent East China Sea (LORCE)Project under contract No.SZ2001。
文摘The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted during the summer of 2022 in the Changjiang River(Yangtze River) Estuary(CJE) and its adjacent waters.The settling column method was employed to measure the sinking velocity(SV) of different size fractions of phytoplankton at the surface of the sea and to analyze their environmental control mechanisms.The findings reveal significant spatial variation in phytoplankton SV(-0.55-2.41 m/d) within the CJE.High-speed sinking was predominantly observed in phosphate-depleted regions beyond the CJE front.At the same time,an upward trend was more commonly observed in the phosphate-rich regions near the CJE mouth.The SV ranges for different sizefractionated phytoplankton,including micro-(>20 μm),nano-(2-20 μm),and picophytoplankton(0.7-2 μm),were-0.50-4.74 m/d,-1.04-1.59 m/d,and-1.24-1.65 m/d,respectively.Correlation analysis revealed a significant negative correlation between SV and dissolved inorganic phosphorus(DIP),implying that the influence of DIP contributes to SV.The variations in phytoplankton alkaline phosphatase activity suggested a significant increase in SV across all size fractions in the event of phosphorus limitation.Phytoplankton communities with limited photo synthetic capacity(maximum photochemical efficience,Fv/Fm <0.3) were found to have higher SV than that of communities with strong capacity,suggesting a link between sinking and alterations in physiological conditions due to phosphate depletion.The findings from the in situ phosphate enrichment experiments confirmed a marked decrease in SV following phosphate supplementation.These findings suggest that phosphorus limitation is the primary driver of elevated SV in the CJE.This study enhances the comprehension of the potential mechanisms underlying hypoxic zone formation in the CJE,providing novel insights into how nearshore eutrophication influences organic carbon migration.
基金supported from the National Natural Science Foundation of China(Nos.52204356,52274342,and 52130408)the Natural Science Foundation of Hunan Province,China(Nos.2023JJ40762 and 2021JJ40731)。
文摘The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification technique with the aims to reveal the effects of phosphorus content on interfacial wettability,deposited film,and interfacial heat transfer behavior.Results showed that when the phosphorus content increased from 0.014wt%to 0.406wt%,the mushy zone enlarged,the complete solidification temperature delayed from1518.3 to 1459.4℃,the final contact angle decreased from 118.4°to 102.8°,indicating improved interfacial contact,and the maximum heat flux increased from 6.9 to 9.2 MW/m2.Increasing the phosphorus content from 0.081wt%to 0.406wt%also accelerated the film deposition rate from 1.57 to 1.73μm per test,resulting in a thickened naturally deposited film with increased thermal resistance that advanced the transition point of heat transfer from the fifth experiment to the third experiment.
基金supported by the National Science Fund for Distin-guished Young Scholars(Grants No.11925205)the National Natural Science Foundation of China(Grant Nos.51921003 and U2341230).
文摘Black phosphorus nanotubes(BPNTs)may have good properties and potential applications.Determining thevibration property of BPNTs is essential for gaining insight into the mechanical behaviour of BPNTs and designingoptimized nanodevices.In this paper,the mechanical behaviour and vibration property of BPNTs are studied viaorthotropic cylindrical shell model and molecular dynamics(MD)simulation.The vibration frequencies of twochiral BPNTs are analysed systematically.According to the results of MD calculations,it is revealed that thenatural frequencies of two BPNTs with approximately equal sizes are unequal at each order,and that the naturalfrequencies of armchair BPNTs are higher than those of zigzag BPNTs.In addition,an armchair BPNTs witha stable structure is considered as the object of research,and the vibration frequencies of BPNTs of differentsizes are analysed.When comparing the MD results,it is found that both the isotropic cylindrical shell modeland orthotropic cylindrical shell model can better predict the thermal vibration of the lower order modes of thelonger BPNTs better.However,for the vibration of shorter and thinner BPNTs,the prediction of the orthotropiccylindrical shell model is obviously superior to the isotropic shell model,thereby further proving the validity ofthe shell model that considers orthotropic for BPNTs.
基金This work was supported by Guizhou Provincial Basic Research Program(Natural Science),Grant Number Qiankehejichu-ZK[2021]YB133Guizhou Provincial Scientific and Technological Program,Grant Number Qiankehehoubuzhu[2020]3001National Natural Science Foundation of China-Guizhou Provincial People’s Government Karst Science Research Centre(U1612442).
文摘The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement.
基金supported by the National Key R&D Program of China (2022YFD2201100)Natural Science Foundation of Heilongjiang Province of China (TD2023C006)the Fundamental Research Funds for the Central Universities (2572022DS13).
文摘Carbon(C),nitrogen(N),and phosphorus(P)are of fundamental importance for growth and nutrient dynamics within plant organs and deserve more attention at regional to global scales.However,our knowledge of how these nutrients vary with tree size,organ age,or root order at the individual level remains limited.We determined C,N,and P contents and their stoichiometric ratios(i.e.,nutrient traits)in needles,branches,and fine roots at different organ ages(0-3-year-old needles and branches)and root orders(1st-4th order roots)from 64 Pinus koraiensis of varying size(Diameter at breast height ranged from 0.3 to 100 cm)in northeast China.Soil factors were also measured.The results show that nutrient traits were regulated by tree size,organ age,or root order rather than soil factors.At a whole-plant level,nutrient traits decreased in needles and fine roots but increased in branches with tree size.At the organ level,age or root order had a negative effect on C,N,and P and a positive effect on stoichiometric ratios.Our results demonstrate that nutrient variations are closely related to organ-specific functions and ecophysiological processes at an individual level.It is suggested that the nutrient acquisition strategy by younger trees and organ fractions with higher nutrient content is for survival.Conversely,nutrient storage strategy in older trees and organ fractions are mainly for steady growth.Our results clarified the nutrient utilization strategies during tree and organ ontogeny and suggest that tree size and organ age or root order should be simultaneously considered to understand the complexities of nutrient variations.
基金supported by CSCEC Technology Research and Development Plan(CSCEC-2020-Z-39).
文摘The effects of different contents of a MgO expansive agent and phosphorus slag on the mechanical properties,shrinkage behavior,and the heat of hydration of concrete were studied.The slump flow,setting time,dry shrinkage,and hydration heat were used as sensitive parameters to assess the response of the considered specimens.As shown by the results,in general,with an increase in the phosphorus slag content,the hydration heat of concrete decreases for all ages,but the early strength displays a downward trend and the dry shrinkage rate increases.The 90-d strength and dry shrinkage of concrete could be improved with a phosphorus residue content between 0%-20%,with the best performances in terms of mechanical properties and shrinkage characteristics being achieved for a content of 20 kg/m^(3).On the basis of these results,it can be concluded that appropriate amounts of phosphorus slag and MgO expansive agent can be used to improve the compressive strength of concrete in the later stage by reducing the hydration heat and dry shrinkage rate,respectively.
基金financially supported by the National Natural Science Foundation of China(32201868 and 32001575)。
文摘Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key role in P absorption.To investigate the genetic variability of RMT under low P availability,we dissected the genetic structure of RMTs by genome-wide association studies(GWAS),linkage mapping and candidate gene association studies(CGAS).A total of 52 suggestive loci were associated with RMTs under P stress conditions in 405 oilseed rape accessions.The purple acid phosphatase gene BnPAP17 was found to control the lateral root number(LRN)and root dry weight(RDW)under low P stress.The expression of BnPAP17 was increased in shoot tissue in P-efficient cultivars compared to root tissue and P-inefficient cultivars in response to low P stress.Moreover,the haplotype of BnPAP17^(Hap3)was detected for the selective breeding of P efficiency in oilseed rape.Over-expression of the BnPAP17^(Hap3)could promote the shoot and root growth with enhanced tolerance to low P stress and organic phosphorus(Po)utilization in oilseed rape.Collectively,these findings increase our understanding of the mechanisms underlying BnPAP17-mediated low P stress tolerance in oilseed rape.
基金Supported by Zhaoqing University Innovation and Entrepreneurship Training Program for College Students(202310580018).
文摘[Objectives]To study the phosphorus removal performance of phosphate accumulating organisms(PAOs).[Methods]Activated sludge from domestic sewage treatment plant was used as the strain source,and phosphate accumulating organisms were screened by plate streaking method and dilution coating plate method.Six kinds of excellent phosphate accumulating organisms were obtained by metachromatic granule staining experiment,total phosphorus experiment and simulated sewage phosphorus removal experiment to assist the observation of bac-terial morphology and experiment of phosphorus removal capacity.In addition,the influencing factors of phosphorus removal capacity(nitrogen source,trace metal ions)were analyzed.[Results]In the case of simulated sewage,the phosphorus removal rate of strain b was the highest,reaching 66.25%,while the phosphorus removal rate of strain e and f was about 10%lower than that of the phosphorus uptake experiment.[Conclusions]This study is expected to provide a theoretical reference for the gradual optimization of the screening method of phosphorus re-moval bacteria in domestic sewage treatment.
