Converter slag is a by-product of the steelmaking process and contains a large amount of Ca,Fe,P and other elements.If the phosphorus in the converter slag can be effectively extracted,the resulting phosphorus can be ...Converter slag is a by-product of the steelmaking process and contains a large amount of Ca,Fe,P and other elements.If the phosphorus in the converter slag can be effectively extracted,the resulting phosphorus can be used as a phosphate fertilizer.Phosphorus in converter slag is mainly enriched in 2CaO·SiO_(2)-3CaO·P_(2)O_(5)(C_(2)S-C_(3)P)solid solution and is easily dissolved in water.Therefore,acid leaching method was used to dissolve the solid solution to extract phosphorus in converter slag,so as to realize the recycling of phosphorus resources in converter slag.The leaching behavior of three actual converter slags from different steel mills in acid leaching solutions composed of citric acid,sodium hydroxide,hydrochloric acid and deionized water was studied by X-ray diffraction,scanning electron microscopy combined with energy dispersive spectrometry,Fourier transform infrared spectroscopy and Raman spectroscopy to reveal the change in object image structure as well as SiO_(4) and PO_(4) tetrahedron before and after acid leaching.The results show that only a small amount of phosphorus in converter slag with too low basicity is enriched in C_(2)S-C_(3)P solid solution,resulting in poor leaching effect.When the converter slag has a high basicity,the removal effect of phosphorus is 70.64%-81.88%.In addition,when the basicity of converter slag is roughly the same,the dephosphorization effect of slag with high FeO content is relatively poor.And acid leaching will cause depolymerization behavior of SiO_(4) and PO_(4) tetrahedron,so that the mole fraction of Q0(Si)(asymmetric stretching vibration of Si-O bond in SiO_(4) tetrahedron with bridge oxygen number of 0)and NBO/Si(non-bridging oxygen in silicate tetrahedra)will increase.Phosphate-containing solids can be obtained from the solution after acid leaching through static precipitation,and the solids have the potential to make phosphate fertilizers.展开更多
The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the ...The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the following order： C2HC3〈C1HC2〈C2HH〈C1HH, and the stability decreases in the following order C2HC3〉C1HC2〉C2HH〉C1HH. The stability of the penta-coordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-coordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated earbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds.展开更多
One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = ...One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = 5.5274（11）, b = 8.1603（16）, c = 28.830（6） A, V = 1300.4（4） A^3, Z = 4, Mr= 276.28, Dc = 1.411 g/cm^3, F（000） = 576,μ = 0.360 mm^-1, R = 0.0259 and wR = 0.0652 for 1414 observed reflections with I 〉 2σ（I）. While compound 2, C14H17N2O2PS, was obtained as a ring-cleavage product of compound 1. This crystal is of monoclinic system, space group P21/c with a = 9.5619（19）, b = 21.879（4）, c = 7.3618（15） A, β= 103.03（3）°, V=1500.4（5） A^3, Z = 4, Mr= 308.33, Dc = 1.365 g/cm^3, F（000） = 648,μ = 0.325 mm^-1, R = 0.0383 and wR =0.0742 for 2283 observed reflections with I 〉 2σ（I）. Phosphorus atom in each compound bonds with sulfur and carbon atoms using sp^3 hybrid orbitals, and crystals of these two compounds are formed and stabilized by intermolecular hydrogen bonds and Van der Waals＇ forces. The special structure of compound 1 leads to its good antimicrobial activity against staphylococcus aureus.展开更多
A new copper（II） complex 3, Cu（C17H13F3O3）2·C5H5N, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group C2/c with a = 17.8511（7）, b = 17.413...A new copper（II） complex 3, Cu（C17H13F3O3）2·C5H5N, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group C2/c with a = 17.8511（7）, b = 17.4136（7）, c = 13.9425（7） A, β = 124.4830（10）°, V = 3572.5（3） A^3, Z = 4, C39H29CuF6NO6, Mr = 785.17,/7（000） = 1604, T = 292（2） K, Dc = 1.460 g/cm^3 and p = 0.691 mm^-1. The structure was refined to R = 0.0477 and wR = 0.1110 for 2935 observed reflections with I 〉 2σ（I）. For the title compound, X-ray analysis reveals that the copper（II） is penta-coordinated by four oxygen atoms from the corresponding 1-（4-（benzyloxy）phenyl）-4,4,4-trifluorobutane-1,3-dione ligands and one nitrogen atom of pyridine, forming a distorted square pyramidal geometry. It is found that the trifluoromethyl group, F（1）/F（1＇）, F（2）/F（2＇） and F（3）/F（3＇））, is disordered over two orientations in an approximate 3：1 ratio.展开更多
The effect of aeration and waterscape structures reaeration system on nitrogen and phosphorus removal efficiency in revetment wetlands was studied by laboratory simulation. The results showed that the removal efficien...The effect of aeration and waterscape structures reaeration system on nitrogen and phosphorus removal efficiency in revetment wetlands was studied by laboratory simulation. The results showed that the removal efficiency of TN, TP in tranquil flow waterscape was 61% and 72%; aeration and waterscape structure system promoted nitrogen and phosphorus removal efficiency in revetment wetland through increasing the DO content in the water, compared with system without artificial oxygen, the removal efficiency of TP in waterscape structures increased by 11. 6%-19. 1%, and that of TN increased by 10.5%-16. 1%; meanwhile, disturbance brought by the waterscape structure systems enhanced the adsorption of TP and flocculation effect; in addition, nitrification was confirmed as the main control step of TN removal in revetment wetland system.展开更多
Understanding how different vegetation-based restoration practices alter soil chemical and microbial characteristics is crucial,as restoration practices influence phosphorus(P)transformation and fractions and modify P...Understanding how different vegetation-based restoration practices alter soil chemical and microbial characteristics is crucial,as restoration practices influence phosphorus(P)transformation and fractions and modify P adsorption behavior during the restoration process of degraded land.This study investigated the impacts of vegetation-based restoration practices on soil chemical and microbial parameters,P fractions,and patterns of P adsorption and desorption,and highlighted the combined influence on P availability.To evaluate the impact of vegetation-based restoration practices on P fractions and adsorption behavior in the semi-arid degraded land in India,this study compared three distinct tree-based restoration systems,including Leucaena leucocephala(Lam.)de Wit-based silviculture system(SCS),Acacia nilotica(L.)Willd.ex Delile-based silvopasture system(SPS),and Emblica officinalis Gaertn-based hortipasture system(HPS),with a natural grassland system(NGS)and a degraded fallow system(FS)as control.The soil samples across various soil depths(0-15,15-30,and 30-45 cm)were collected.The findings demonstrated that SCS,SPS,and HPS significantly improved soil organic carbon(SOC)and nutrient availability.Moreover,SCS and SPS resulted in increased microbial biomass phosphorus(MBP)content and phosphatase enzyme activity.The P fractionation analysis revealed that ferrum-associated phosphorus(Fe-P)was the major P fraction,followed by aluminum-associated phosphorus(Al-P),reflecting the dominance of ferrum(Fe)and aluminum(Al)oxides in the semi-arid degraded land.Compared with FS,vegetation-based restoration practices significantly increased various P fractions across soil depths.Additionally,P adsorption and desorption analysis indicated a lower adsorption capacity in tree-based restoration systems than in FS,with FS soils adsorbing higher P quantities in the adsorption phase but releasing less P during the desorption phase.This study revealed that degraded soils responded positively to ecological restoration in terms of P fraction and desorption behavior,influencing the resupply of P in restoration systems.Consequently,litter rich N-fixing tree-based restoration systems(i.e.,SCS and SPS)increased total phosphorus(TP)stock for plants and sustained the potential for long-term P supply in semi-arid ecosystems.With the widespread adoption of restoration practices across degraded landscapes,SCS and SPS would significantly contribute to soil restoration and improve productivity by maintaining the soil P supply in semi-arid ecosystems in India.展开更多
The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have...The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have not met the demand for higher energy storage owing to the deficiency of low lithium storage capacity.In the current work,we focus on designing one composite anode material with multiscale porous(MP)structure and phosphorus(P)doping.The coupling effects of three-dimensional(3D)interconnected skeleton,hollow pore channels,and P doping can facilitate the electrolyte diffusion and the mass transfer,as well as accommodate the volume changes during lithiation/delithiation processes.As expected,the as-prepared MP-SiGeSnSbPAl composite exhibits superior lithium storage performance,achieving a specific capacity of 827.9 mAh/g after 150 cycles at 200 mA/g and maintaining the high capacity of 456.7 mAh/g after 400 cycles at 1 A/g.Contrastively,the corresponding surplus capacities are only 590.3 and 225.7 mAh/g for the non-doped counterparts,respectively.In particular,MP-SiGeSnSbPAl displays much more stable cycling performances under the measurement of high areal mass loading of~3 mg/cm^(2)and the full-cell tests with the lithium iron phosphate as the cathode.This work witnesses one scalable protocol for preparing multinary Si-based composite in terms of facile operation and high lithium storage performances.展开更多
In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail...In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.展开更多
Microorganisms regulate the responses of terrestrial ecosystems to anthropogenic nutrient inputs.The escalation of anthropogenic activities has resulted in a rise in the primary terrestrial constraining elements,namel...Microorganisms regulate the responses of terrestrial ecosystems to anthropogenic nutrient inputs.The escalation of anthropogenic activities has resulted in a rise in the primary terrestrial constraining elements,namely nitrogen(N)and phosphorus(P).Nevertheless,the specific mechanisms governing the influence of soil microbial community structure and ecological processes in ecologically vulnerable and delicate semi-arid loess agroecosystems remain inadequately understood.Therefore,we explored the effects of different N and P additions on soil microbial community structure and its associated ecological processes in the farmland of Chinese Loess Plateau based on a 36-a long-term experiment.Nine fertilization treatments with complete interactions of high,medium,and low N and P gradients were set up.Soil physical and chemical properties,along with the microbial community structure were measured in this study.Additionally,relevant ecological processes such as microbial biomass,respiration,N mineralization,and enzyme activity were quantified.To elucidate the relationships between these variables,we examined correlation-mediated processes using statistical techniques,including redundancy analysis(RDA)and structural equation modeling(SEM).The results showed that the addition of N alone had a detrimental effect on soil microbial biomass,mineralized N accumulation,andβ-1,4-glucosidase activity.Conversely,the addition of P exhibited an opposing effect,leading to positive influences on these soil parameters.The interactive addition of N and P significantly changed the microbial community structure,increasing microbial activity(microbial biomass and soil respiration),but decreasing the accumulation of mineralized N.Among them,N24P12 treatment showed the greatest increase in the soil nutrient content and respiration.N12P12 treatment increased the overall enzyme activity and total phospholipid fatty acid(PLFA)content by 70.93%.N and P nutrient contents of the soil dominate the microbial community structure and the corresponding changes in hydrolytic enzymes.Soil microbial biomass,respiration,and overall enzyme activity are driven by mineralized N.Our study provides a theoretical basis for exploring energy conversion processes of soil microbial community and environmental sustainability under long-term N and P additions in semi-arid loess areas.展开更多
The phosphorus fixation capacity of some slag systems,such as Ce_(2)O_(3)-containing slag,has hardly been investigated from a thermodynamics view due to the lack of relevant thermodynamic data.Since the macroscopic pr...The phosphorus fixation capacity of some slag systems,such as Ce_(2)O_(3)-containing slag,has hardly been investigated from a thermodynamics view due to the lack of relevant thermodynamic data.Since the macroscopic properties are primarily determined by the microscopic structure,the correlation between phosphorus fixation capacity and slag structure was explored by spectroscopy(XPS),Raman spectroscopy,and ferromanganese dephosphorization experiments.The results show that the predominant species of P^(5+)are Q_(P)^(0)(PO_(4)^(3-))and Q_(P)^(1)(P_(2)O_(7)^(4-))units in the CaO^(-)SiO_(2)-Al_(2)O_(3)-MnO^(-)Ce_(2)O_(3)-P_(2)O_(5)quenched slag,and the phosphorus fixation capacity increases with the Q_(P)^(1)(P_(2)O_(7)^(4-))unit to Q_(P)^(0)(PO_(4)^(3-))unit transformation(the P-O^(0) bond to P-O^(-)bond transformation)since the electron cloud density between P and O atoms increases and the average radius of P-O bonds decreases.Especially,CaO or Ce_(2)O_(3) as a network modifier can release the O_(2)-and promote the P-O^(0) bond to P-O^(-)bond(connected to Ca^(2+),/Ce^(3+))transformation in the quenched slag.Furthermore,the phosphorus enrichment phases in the slow cooling slag are confirmed as nCa_(2)SiO_(3)-Ca_(3)P_(2)O_(8)(nC_(2)S-C3P)and CePO_(4) solid solutions by the scan electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive spectrometer(EDS)methods.The re sults show Ce_(2)O_(3) can depolymerize the polyphosphate structure partially replacing CaO after introducing Ce_(2)O_(3) into CaO based slag because of its strong ability to donate electrons.The above results not only help to understand the dependence of phosphorus fixation capacity on slag composition from a structural view,but also provide the theoretical guidance for optimizing the composition of Ce_(2)O_(3)-containing dephosphorization slag.展开更多
Biofilms have important effects on nutrient cycling in aquatic ecosystems.However,publications about the community structure and functions under laboratory conditions are rare.This study focused on the developmental a...Biofilms have important effects on nutrient cycling in aquatic ecosystems.However,publications about the community structure and functions under laboratory conditions are rare.This study focused on the developmental and physiological properties of cultured biofilms under various phosphorus concentrations performed in a closely controlled continuous flow incubator.The results showed that the biomass（Chl a）and photosynthesis of algae were inhibited under P-limitation conditions,while the phosphatase activity and P assimilation rate were promoted.The algal community structure of biofilms was more likely related to the colonization stage than with the phosphorus availability.Cyanobacteria were more competitive than other algae in biofilms,particularly when cultured under low P levels.A dominance shift occurred from non-filamentous algae in the early stage to filamentous algae in the mid and late stages under P concentrations of 0.01,0.1 and 0.6 mg/L.However,the total N content,dry weight biomass and bacterial community structure of biofilms were unaffected by phosphorus availability.This may be attributed to the low respiration rate,high accumulation of extracellular polymeric substances and high alkaline phosphatase activity in biofilms when phosphorus availability was low.The bacterial community structure differed over time,while there was little difference between the four treatments,which indicated that it was mainly affected by the colonization stage of the biofilms rather than the phosphorus availability.Altogether,these results suggested that the development of biofilms was influenced by the phosphorus availability and/or the colonization stage and hence determined the role that biofilms play in the overlying water.展开更多
Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morpho...Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.展开更多
The title compound Ph3P=C（H）C（O）PhNO2 （L） has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-（3,nitrophenyl）ethanone followed by the addition of alkaline solution of sod...The title compound Ph3P=C（H）C（O）PhNO2 （L） has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-（3,nitrophenyl）ethanone followed by the addition of alkaline solution of sodium hydroxide. The yellow crystals of the title ylide were grown in methanol/chloroform solution by drop method without stirring at room temperature. The solid state structure of ylide has been established by X-ray crystallography analysis. In the molecule of the title compound, the geometry around the P atom is nearly tetrahedral and the O atom is in synperiplanar orientation to the P atom. The nitrophenyl ring is twisted with respect to the plane of the carbonyl group through an angle of 36.6（1）°. The crystal （C26H20NO3P, Mr = 425.40） belongs to the monoclinic system, space group P21/n with a = 10.889（3）, b = 14.467（3）, e = 13.872（4）A, β = 103.08（3）°, V = 2128.6（10） A3, Z= 4, T= 100（2） K, R = 0.059 and wR = 0.163 for 3984 observed reflections with I〉 2σ（I）.展开更多
A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry packag...A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry package and the coexistence theory of slag structure were adopted for theoretical analysis. The gas-based reduction was carried out using a fixed bed reactor and the ore sample of 80 g with an average particle size of 2 mm were reduced using CO or H2 at temperature of 1 073 K for 5 hours. 50 g of the reduced sample with 3.0% CaO as additive was then subjected to melt separation in an electric furnace at temperature of 1 873 K under Ar atmosphere. In each run, SEM, EDS, optical microscopic examination and chemical analysis of the reduced ore sample, the metal sample and the slag sample were conducted. Results of all gas-based reduction experiments showed that iron metallization ratios were some 65% and the phosphorus compounds in the ore remained unchanged. It was agreed well with the simula- tions except for the iron metallization rate being less than predicted value; this difference was attributed to kinetics. Results of melt separation experiments showed that P content in metal samples is 0.33% （metal sample from H2 reduction product） and 0.27% （metal sample from CO reduction product）. The phosphorus partition ratios of both cases were less than predicted values. Some P in the metal samples existed as slag inclusion was considered to be the reason for this discrepancy.展开更多
Hydration characteristics of Portland cement paste with phosphorus slag powder incorporated and hydration kinetics was investigated with SEM, X-ray diffraction, DTA-TG and calorimeter Ⅱ80. Results showed that phospho...Hydration characteristics of Portland cement paste with phosphorus slag powder incorporated and hydration kinetics was investigated with SEM, X-ray diffraction, DTA-TG and calorimeter Ⅱ80. Results showed that phosphorus slag powder could reduce total amount of hydration products yet had little influence on the type of hydration products. The total amount of heat of hydration was decreased by 49.11% and the final setting was postponed by 2.28 h when phosphorus slag powder substituted 35% Portland cement by mass. The accelerating stage of this composite paste was controlled by catalysis, decreasing stage controlled by both catalysis and diffusion while stabilizing stage by diffusion alone. Hydration resistance and activation energy were reduced and hydration speed was accelerated.展开更多
Two-dimensional black phosphorus(2D BP),well known as phosphorene,has triggered tremendous attention since the first discovery in 2014.The unique puckered monolayer structure endows 2D BP intriguing properties,which f...Two-dimensional black phosphorus(2D BP),well known as phosphorene,has triggered tremendous attention since the first discovery in 2014.The unique puckered monolayer structure endows 2D BP intriguing properties,which facilitate its potential applications in various fields,such as catalyst,energy storage,sensor,etc.Owing to the large surface area,good electric conductivity,and high theoretical specific capacity,2D BP has been widely studied as electrode materials and significantly enhanced the performance of energy storage devices.With the rapid development of energy storage devices based on 2D BP,a timely review on this topic is in demand to further extend the application of 2D BP in energy storage.In this review,recent advances in experimental and theoretical development of 2D BP are presented along with its structures,properties,and synthetic methods.Particularly,their emerging applications in electrochemical energy storage,including Li−/K−/Mg−/Na-ion,Li–S batteries,and supercapacitors,are systematically summarized with milestones as well as the challenges.Benefited from the fast-growing dynamic investigation of 2D BP,some possible improvements and constructive perspectives are provided to guide the design of 2D BP-based energy storage devices with high performance.展开更多
The band structure, density of states, optical properties, carrier mobility, and loss function of graphene, black phosphorus（BP）, and molybdenum disulfide（MoS_2） were investigated by the first-principles method wi...The band structure, density of states, optical properties, carrier mobility, and loss function of graphene, black phosphorus（BP）, and molybdenum disulfide（MoS_2） were investigated by the first-principles method with the generalized-gradient approximation. The graphene was a zero-band-gap semiconductor. The band gaps of BP and MoS_2 were strongly dependent on the number of layers. The relationships between layers and band gap were built to predict the band gap of few-layer BP and MoS_2. The absorption showed an explicit anisotropy for light polarized in（1 0 0） and（0 0 1） directions of graphene, BP,and MoS_2. This behavior may be readily detected in spectroscopic measurements and exploited for optoelectronic applications. Moreover, graphene（5.27 × 10~4 cm^2·V^（-1）·s^（-1））, BP（1.5 × 10~4 cm^2·V^（-1）·s^（-1））, and MoS_2（2.57×102 cm2·V-1·s-1）have high carrier mobility. These results show that graphene, BP, and MoS_2 are promising candidates for future electronic applications.展开更多
In order to reveal the mechanism of silicon(Si)fertilizer in improving nitrogen(N)and phosphorus(P)nutrient availability in paddy soil,we designed a series of soil culture experiments by combining application of varyi...In order to reveal the mechanism of silicon(Si)fertilizer in improving nitrogen(N)and phosphorus(P)nutrient availability in paddy soil,we designed a series of soil culture experiments by combining application of varying Si fertilizer concentrations with fixed N and P fertilizer concentrations.Following the recommendations of fertilizer manufacturers and local farmers,we applied Si in concentrations of 0,5.2,10.4,15.6,and 20.8μg/kg.At each concentration of added Si,the availability of soil N and P nutrients,soil microbial activity,numbers of ammonia-oxidizing bacteria and P-decomposing bacteria which means that the organic P is decomposed into inorganic nutrients which can be absorbed and utilized by plants,and urease and phosphatase activity first increased,and then decreased,as Si was added to the soil.These indicators reached their highest levels with a Si application rate of 15.6μg/kg,showing values respectively 19.78%,105.09%,8.34%,73.12%,130.36%,28.12%,and 20.15%higher than those of the controls.Appropriate Si application(10.4 to 15.6µg/kg)could significantly increase the richness of the soil microbial community involved in cycling of N and P nutrients in the soil.When the Si application rate was 15.6μg/kg,parameters for characterizing microbial abundance such as sequence numbers,operational taxonomic unit(OTU)number,and correlation indices of microbial community richness such as Chao1 index,the adaptive coherence estimator(ACE)index,Shannon index,and Simpson index all reached maximum values,with amounts increased by 14.46%,10.01%,23.80%,30.54%,0.18%,and 2.64%,respectively,compared with the control group.There is also a good correlation between N and P mineralization and addition of Si fertilizer.The correlation coefficients between the ratio of available P/total P(AP/TP)and the number of ammonia-oxidizing bacteria,AP/TP and acid phosphatase activity(AcPA),AP/TP and the Shannon index,the ratio of available N/total amount of N(AN/TN)and the number of ammoniated bacteria,and AN/TN and AcPA were 0.9290,0.9508,0.9202,0.9140,and 0.9366,respectively.In summary,these results revealed that enhancement of soil microbial community structure diversity and soil microbial activity by appropriate application of Si is the key ecological mechanism by which application of Si fertilizer improves N and P nutrient availability.展开更多
The structure ofV2O5-P2O5-Sb2O3-Bi2O3glass and its state of crystallization were studied by means of infrared spectroscopy and X-ray diffraction analysis. The results indicate that, in this glass, V and P exist mainly...The structure ofV2O5-P2O5-Sb2O3-Bi2O3glass and its state of crystallization were studied by means of infrared spectroscopy and X-ray diffraction analysis. The results indicate that, in this glass, V and P exist mainly in the form of a single-stranded linear （VO3）n and an isolated （PO4） tetrahedral with no double bond. Partial V and P are connected through O, forming an amorphous structure of layered vana- dium phosphate. Trivalent Sb3＋ and Bi3＋ open the V=O bond and appear in interlayers, so a weak three-dimensional structure is connected successfully. Along with the substitution of Sb203 for partial V205 or that of P205 for partial V205, the network structure of the glass is rein- forced, and the crystallization is reduced.展开更多
Reducing phosphorus (P) loads from soils to surface waters is necessary for solving the problem of eutrophication. Many industrial by-products have been shown to sorb appreciable amounts of dissolved P from solution a...Reducing phosphorus (P) loads from soils to surface waters is necessary for solving the problem of eutrophication. Many industrial by-products have been shown to sorb appreciable amounts of dissolved P from solution and it has been proposed to use P sorption materials (PSMs) such as steel slag in landscape scale “filters” for trapping dissolved P in runoff. The objective of this study was to model the effect of retention time (RT) and P concentration on P sorption by steel slag and a surface modified slag in a flow-through system. Sorption of P onto steel slag and rejuvenated-modified steel slag was measured using a traditional batch isotherm and a flow-through setting at several RTs and P concentrations. Flow-through data were used to produce a model that estimated P sorption based on RT and P concentration. The model was tested on a pilot-scale pond filter consisting of the same slag materials. For both the materials, flow-through tests indicated an increase in RT increased P removal efficiency but decreased the total amount of P removed at saturation. The Langmuir model developed from batch isotherms overestimated and underestimated P sorption in normal and rejuvenated slag respectively, relative to flow-through. Normal and rejuvenated slag removed 38 and 36% of P in the pilot-scale pond filter after 2 weeks of pumping. The Langmuir equation poorly predicted P sorption in the pond filter while the flow-through model produced reasonable estimates. Results suggest that flow-through methodology is necessary for estimating P sorption in the context of landscape P filters.展开更多
基金supported by Hebei Provincial Natural Science Foundation of China (Grant No.H2022209089)Basic Scientific Research Business Expenses of Colleges and Universities in Hebei Province (Grant No.JYG2022001)+3 种基金Open Fund Project of the Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education (Grant No.FMRUlab23-03)the Basic Scientific Research Business Expenses Research Projects of Colleges and Universities in Hebei Province (Grant No.JQN2023008)the National Natural Science Foundation of China (Grant No.52074128)Hebei Province Innovation Ability Promotion Plan Project (Grant No.23561001D).
文摘Converter slag is a by-product of the steelmaking process and contains a large amount of Ca,Fe,P and other elements.If the phosphorus in the converter slag can be effectively extracted,the resulting phosphorus can be used as a phosphate fertilizer.Phosphorus in converter slag is mainly enriched in 2CaO·SiO_(2)-3CaO·P_(2)O_(5)(C_(2)S-C_(3)P)solid solution and is easily dissolved in water.Therefore,acid leaching method was used to dissolve the solid solution to extract phosphorus in converter slag,so as to realize the recycling of phosphorus resources in converter slag.The leaching behavior of three actual converter slags from different steel mills in acid leaching solutions composed of citric acid,sodium hydroxide,hydrochloric acid and deionized water was studied by X-ray diffraction,scanning electron microscopy combined with energy dispersive spectrometry,Fourier transform infrared spectroscopy and Raman spectroscopy to reveal the change in object image structure as well as SiO_(4) and PO_(4) tetrahedron before and after acid leaching.The results show that only a small amount of phosphorus in converter slag with too low basicity is enriched in C_(2)S-C_(3)P solid solution,resulting in poor leaching effect.When the converter slag has a high basicity,the removal effect of phosphorus is 70.64%-81.88%.In addition,when the basicity of converter slag is roughly the same,the dephosphorization effect of slag with high FeO content is relatively poor.And acid leaching will cause depolymerization behavior of SiO_(4) and PO_(4) tetrahedron,so that the mole fraction of Q0(Si)(asymmetric stretching vibration of Si-O bond in SiO_(4) tetrahedron with bridge oxygen number of 0)and NBO/Si(non-bridging oxygen in silicate tetrahedra)will increase.Phosphate-containing solids can be obtained from the solution after acid leaching through static precipitation,and the solids have the potential to make phosphate fertilizers.
文摘The structure and energy of the carbonium ions formed upon protonation of butane were studied by the DFT methods. Four stable structures are identified for the protonated form of n-butane, the energy increases in the following order： C2HC3〈C1HC2〈C2HH〈C1HH, and the stability decreases in the following order C2HC3〉C1HC2〉C2HH〉C1HH. The stability of the penta-coordinated carbonium ions may be explained by the electron distribution in the three-center-two-electron bonds. The delocalization of the penta-coordinated carbonium ion CHC with three-center-two-electron bonds on positive charges was stronger than that of the penta-coordinated earbonium ion CHH with three-center-two-electron bonds and its stability was higher than that of the penta-coordinated carbonium ion CHH with three-center-two-electron bonds.
基金This work was supported by the National Natural Science Foundation of China (20271046), Natural Science Foundation of Henan Education Department (2004150004) and Natural Foundation of Henan Province (200011500027)
文摘One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = 5.5274（11）, b = 8.1603（16）, c = 28.830（6） A, V = 1300.4（4） A^3, Z = 4, Mr= 276.28, Dc = 1.411 g/cm^3, F（000） = 576,μ = 0.360 mm^-1, R = 0.0259 and wR = 0.0652 for 1414 observed reflections with I 〉 2σ（I）. While compound 2, C14H17N2O2PS, was obtained as a ring-cleavage product of compound 1. This crystal is of monoclinic system, space group P21/c with a = 9.5619（19）, b = 21.879（4）, c = 7.3618（15） A, β= 103.03（3）°, V=1500.4（5） A^3, Z = 4, Mr= 308.33, Dc = 1.365 g/cm^3, F（000） = 648,μ = 0.325 mm^-1, R = 0.0383 and wR =0.0742 for 2283 observed reflections with I 〉 2σ（I）. Phosphorus atom in each compound bonds with sulfur and carbon atoms using sp^3 hybrid orbitals, and crystals of these two compounds are formed and stabilized by intermolecular hydrogen bonds and Van der Waals＇ forces. The special structure of compound 1 leads to its good antimicrobial activity against staphylococcus aureus.
基金supported by the Natural Science Foundation of the Educational Commission of Hubei Province (No. Q20082202)
文摘A new copper（II） complex 3, Cu（C17H13F3O3）2·C5H5N, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group C2/c with a = 17.8511（7）, b = 17.4136（7）, c = 13.9425（7） A, β = 124.4830（10）°, V = 3572.5（3） A^3, Z = 4, C39H29CuF6NO6, Mr = 785.17,/7（000） = 1604, T = 292（2） K, Dc = 1.460 g/cm^3 and p = 0.691 mm^-1. The structure was refined to R = 0.0477 and wR = 0.1110 for 2935 observed reflections with I 〉 2σ（I）. For the title compound, X-ray analysis reveals that the copper（II） is penta-coordinated by four oxygen atoms from the corresponding 1-（4-（benzyloxy）phenyl）-4,4,4-trifluorobutane-1,3-dione ligands and one nitrogen atom of pyridine, forming a distorted square pyramidal geometry. It is found that the trifluoromethyl group, F（1）/F（1＇）, F（2）/F（2＇） and F（3）/F（3＇））, is disordered over two orientations in an approximate 3：1 ratio.
基金Sponsored by Shaanxi Provincial Water Conservancy Science and Technology Program(2015slkj-17)
文摘The effect of aeration and waterscape structures reaeration system on nitrogen and phosphorus removal efficiency in revetment wetlands was studied by laboratory simulation. The results showed that the removal efficiency of TN, TP in tranquil flow waterscape was 61% and 72%; aeration and waterscape structure system promoted nitrogen and phosphorus removal efficiency in revetment wetland through increasing the DO content in the water, compared with system without artificial oxygen, the removal efficiency of TP in waterscape structures increased by 11. 6%-19. 1%, and that of TN increased by 10.5%-16. 1%; meanwhile, disturbance brought by the waterscape structure systems enhanced the adsorption of TP and flocculation effect; in addition, nitrification was confirmed as the main control step of TN removal in revetment wetland system.
基金funded by Indian Council of Agricultural Research,Ministry of Agriculture and Farmers Welfare,India(AGRIL.EDN/1/1/2022-EXAM CELL).
文摘Understanding how different vegetation-based restoration practices alter soil chemical and microbial characteristics is crucial,as restoration practices influence phosphorus(P)transformation and fractions and modify P adsorption behavior during the restoration process of degraded land.This study investigated the impacts of vegetation-based restoration practices on soil chemical and microbial parameters,P fractions,and patterns of P adsorption and desorption,and highlighted the combined influence on P availability.To evaluate the impact of vegetation-based restoration practices on P fractions and adsorption behavior in the semi-arid degraded land in India,this study compared three distinct tree-based restoration systems,including Leucaena leucocephala(Lam.)de Wit-based silviculture system(SCS),Acacia nilotica(L.)Willd.ex Delile-based silvopasture system(SPS),and Emblica officinalis Gaertn-based hortipasture system(HPS),with a natural grassland system(NGS)and a degraded fallow system(FS)as control.The soil samples across various soil depths(0-15,15-30,and 30-45 cm)were collected.The findings demonstrated that SCS,SPS,and HPS significantly improved soil organic carbon(SOC)and nutrient availability.Moreover,SCS and SPS resulted in increased microbial biomass phosphorus(MBP)content and phosphatase enzyme activity.The P fractionation analysis revealed that ferrum-associated phosphorus(Fe-P)was the major P fraction,followed by aluminum-associated phosphorus(Al-P),reflecting the dominance of ferrum(Fe)and aluminum(Al)oxides in the semi-arid degraded land.Compared with FS,vegetation-based restoration practices significantly increased various P fractions across soil depths.Additionally,P adsorption and desorption analysis indicated a lower adsorption capacity in tree-based restoration systems than in FS,with FS soils adsorbing higher P quantities in the adsorption phase but releasing less P during the desorption phase.This study revealed that degraded soils responded positively to ecological restoration in terms of P fraction and desorption behavior,influencing the resupply of P in restoration systems.Consequently,litter rich N-fixing tree-based restoration systems(i.e.,SCS and SPS)increased total phosphorus(TP)stock for plants and sustained the potential for long-term P supply in semi-arid ecosystems.With the widespread adoption of restoration practices across degraded landscapes,SCS and SPS would significantly contribute to soil restoration and improve productivity by maintaining the soil P supply in semi-arid ecosystems in India.
基金supported by National Science Foundation of Shandong Province(Nos.ZR2023ME155 and ZR2023ME085)the Taishan Scholar Project of Shandong Province(Nos.tsqn202306226 and tsqn202211171).
文摘The development of high-performance lithium-ion batteries(LIBs)hinges on searching for advanced anode materials with large specific capacities as well as high cycling stability.However,traditional graphite anodes have not met the demand for higher energy storage owing to the deficiency of low lithium storage capacity.In the current work,we focus on designing one composite anode material with multiscale porous(MP)structure and phosphorus(P)doping.The coupling effects of three-dimensional(3D)interconnected skeleton,hollow pore channels,and P doping can facilitate the electrolyte diffusion and the mass transfer,as well as accommodate the volume changes during lithiation/delithiation processes.As expected,the as-prepared MP-SiGeSnSbPAl composite exhibits superior lithium storage performance,achieving a specific capacity of 827.9 mAh/g after 150 cycles at 200 mA/g and maintaining the high capacity of 456.7 mAh/g after 400 cycles at 1 A/g.Contrastively,the corresponding surplus capacities are only 590.3 and 225.7 mAh/g for the non-doped counterparts,respectively.In particular,MP-SiGeSnSbPAl displays much more stable cycling performances under the measurement of high areal mass loading of~3 mg/cm^(2)and the full-cell tests with the lithium iron phosphate as the cathode.This work witnesses one scalable protocol for preparing multinary Si-based composite in terms of facile operation and high lithium storage performances.
基金This work was supported by the Major State Basic Research Development Program of China(973 Program)under the contract number of 2004CB619108the National Natural Science Foundation of China(No.50574018)the NECT-04-0278 Project of the Ministry of Education of China.
文摘In the present paper, low carbon steel strips with different phosphorus contents were produced using a twin roll strip casting process. The solidification structure was studied and its features were analyzed in detail. It was found that the strips possessed a fine microstructure compared with the mould cast steels. With increasing phosphorus content more ferrite has been formed with finer grains.
基金funded by the Project of Science and Technology Department of Shaanxi Province,China(2022NY-074)the National Natural Science Foundation of China(41501255)+1 种基金the Xi'an Science and Technology Project(21NYYF0033)the Fundamental Research Funds for the Central Universities(SYJS202224,GK202206032).
文摘Microorganisms regulate the responses of terrestrial ecosystems to anthropogenic nutrient inputs.The escalation of anthropogenic activities has resulted in a rise in the primary terrestrial constraining elements,namely nitrogen(N)and phosphorus(P).Nevertheless,the specific mechanisms governing the influence of soil microbial community structure and ecological processes in ecologically vulnerable and delicate semi-arid loess agroecosystems remain inadequately understood.Therefore,we explored the effects of different N and P additions on soil microbial community structure and its associated ecological processes in the farmland of Chinese Loess Plateau based on a 36-a long-term experiment.Nine fertilization treatments with complete interactions of high,medium,and low N and P gradients were set up.Soil physical and chemical properties,along with the microbial community structure were measured in this study.Additionally,relevant ecological processes such as microbial biomass,respiration,N mineralization,and enzyme activity were quantified.To elucidate the relationships between these variables,we examined correlation-mediated processes using statistical techniques,including redundancy analysis(RDA)and structural equation modeling(SEM).The results showed that the addition of N alone had a detrimental effect on soil microbial biomass,mineralized N accumulation,andβ-1,4-glucosidase activity.Conversely,the addition of P exhibited an opposing effect,leading to positive influences on these soil parameters.The interactive addition of N and P significantly changed the microbial community structure,increasing microbial activity(microbial biomass and soil respiration),but decreasing the accumulation of mineralized N.Among them,N24P12 treatment showed the greatest increase in the soil nutrient content and respiration.N12P12 treatment increased the overall enzyme activity and total phospholipid fatty acid(PLFA)content by 70.93%.N and P nutrient contents of the soil dominate the microbial community structure and the corresponding changes in hydrolytic enzymes.Soil microbial biomass,respiration,and overall enzyme activity are driven by mineralized N.Our study provides a theoretical basis for exploring energy conversion processes of soil microbial community and environmental sustainability under long-term N and P additions in semi-arid loess areas.
基金Project supported by the National Natural Science Foundation of China(51874082)NSFC-Liaoning Joint Fund(U1908224)。
文摘The phosphorus fixation capacity of some slag systems,such as Ce_(2)O_(3)-containing slag,has hardly been investigated from a thermodynamics view due to the lack of relevant thermodynamic data.Since the macroscopic properties are primarily determined by the microscopic structure,the correlation between phosphorus fixation capacity and slag structure was explored by spectroscopy(XPS),Raman spectroscopy,and ferromanganese dephosphorization experiments.The results show that the predominant species of P^(5+)are Q_(P)^(0)(PO_(4)^(3-))and Q_(P)^(1)(P_(2)O_(7)^(4-))units in the CaO^(-)SiO_(2)-Al_(2)O_(3)-MnO^(-)Ce_(2)O_(3)-P_(2)O_(5)quenched slag,and the phosphorus fixation capacity increases with the Q_(P)^(1)(P_(2)O_(7)^(4-))unit to Q_(P)^(0)(PO_(4)^(3-))unit transformation(the P-O^(0) bond to P-O^(-)bond transformation)since the electron cloud density between P and O atoms increases and the average radius of P-O bonds decreases.Especially,CaO or Ce_(2)O_(3) as a network modifier can release the O_(2)-and promote the P-O^(0) bond to P-O^(-)bond(connected to Ca^(2+),/Ce^(3+))transformation in the quenched slag.Furthermore,the phosphorus enrichment phases in the slow cooling slag are confirmed as nCa_(2)SiO_(3)-Ca_(3)P_(2)O_(8)(nC_(2)S-C3P)and CePO_(4) solid solutions by the scan electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive spectrometer(EDS)methods.The re sults show Ce_(2)O_(3) can depolymerize the polyphosphate structure partially replacing CaO after introducing Ce_(2)O_(3) into CaO based slag because of its strong ability to donate electrons.The above results not only help to understand the dependence of phosphorus fixation capacity on slag composition from a structural view,but also provide the theoretical guidance for optimizing the composition of Ce_(2)O_(3)-containing dephosphorization slag.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No2012ZX07103003-02)
文摘Biofilms have important effects on nutrient cycling in aquatic ecosystems.However,publications about the community structure and functions under laboratory conditions are rare.This study focused on the developmental and physiological properties of cultured biofilms under various phosphorus concentrations performed in a closely controlled continuous flow incubator.The results showed that the biomass（Chl a）and photosynthesis of algae were inhibited under P-limitation conditions,while the phosphatase activity and P assimilation rate were promoted.The algal community structure of biofilms was more likely related to the colonization stage than with the phosphorus availability.Cyanobacteria were more competitive than other algae in biofilms,particularly when cultured under low P levels.A dominance shift occurred from non-filamentous algae in the early stage to filamentous algae in the mid and late stages under P concentrations of 0.01,0.1 and 0.6 mg/L.However,the total N content,dry weight biomass and bacterial community structure of biofilms were unaffected by phosphorus availability.This may be attributed to the low respiration rate,high accumulation of extracellular polymeric substances and high alkaline phosphatase activity in biofilms when phosphorus availability was low.The bacterial community structure differed over time,while there was little difference between the four treatments,which indicated that it was mainly affected by the colonization stage of the biofilms rather than the phosphorus availability.Altogether,these results suggested that the development of biofilms was influenced by the phosphorus availability and/or the colonization stage and hence determined the role that biofilms play in the overlying water.
基金supported by the Ruijin Hospital Guangci Introducing Talent Projectfinancial support from National Natural Science Foundation of China(82372145)+4 种基金the Research Fellow(Grant No.353146)Research Project(347897)Solutions for Health Profile(336355)InFLAMES Flagship(337531)grants from Academy of Finlandthe Finland China Food and Health International Pilot Project funded by the Finnish Ministry of Education and Culture.
文摘Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.
文摘The title compound Ph3P=C（H）C（O）PhNO2 （L） has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-（3,nitrophenyl）ethanone followed by the addition of alkaline solution of sodium hydroxide. The yellow crystals of the title ylide were grown in methanol/chloroform solution by drop method without stirring at room temperature. The solid state structure of ylide has been established by X-ray crystallography analysis. In the molecule of the title compound, the geometry around the P atom is nearly tetrahedral and the O atom is in synperiplanar orientation to the P atom. The nitrophenyl ring is twisted with respect to the plane of the carbonyl group through an angle of 36.6（1）°. The crystal （C26H20NO3P, Mr = 425.40） belongs to the monoclinic system, space group P21/n with a = 10.889（3）, b = 14.467（3）, e = 13.872（4）A, β = 103.08（3）°, V = 2128.6（10） A3, Z= 4, T= 100（2） K, R = 0.059 and wR = 0.163 for 3984 observed reflections with I〉 2σ（I）.
基金Sponsored by National Natural Science Foundation of China and Baosteel(50834007)
文摘A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry package and the coexistence theory of slag structure were adopted for theoretical analysis. The gas-based reduction was carried out using a fixed bed reactor and the ore sample of 80 g with an average particle size of 2 mm were reduced using CO or H2 at temperature of 1 073 K for 5 hours. 50 g of the reduced sample with 3.0% CaO as additive was then subjected to melt separation in an electric furnace at temperature of 1 873 K under Ar atmosphere. In each run, SEM, EDS, optical microscopic examination and chemical analysis of the reduced ore sample, the metal sample and the slag sample were conducted. Results of all gas-based reduction experiments showed that iron metallization ratios were some 65% and the phosphorus compounds in the ore remained unchanged. It was agreed well with the simula- tions except for the iron metallization rate being less than predicted value; this difference was attributed to kinetics. Results of melt separation experiments showed that P content in metal samples is 0.33% （metal sample from H2 reduction product） and 0.27% （metal sample from CO reduction product）. The phosphorus partition ratios of both cases were less than predicted values. Some P in the metal samples existed as slag inclusion was considered to be the reason for this discrepancy.
基金Funded by the National Natural Science Foundation of China (No. 50539010)China Central Special Non-profit Research Funds for Institutes (Nos.200901066 and YWF090)
文摘Hydration characteristics of Portland cement paste with phosphorus slag powder incorporated and hydration kinetics was investigated with SEM, X-ray diffraction, DTA-TG and calorimeter Ⅱ80. Results showed that phosphorus slag powder could reduce total amount of hydration products yet had little influence on the type of hydration products. The total amount of heat of hydration was decreased by 49.11% and the final setting was postponed by 2.28 h when phosphorus slag powder substituted 35% Portland cement by mass. The accelerating stage of this composite paste was controlled by catalysis, decreasing stage controlled by both catalysis and diffusion while stabilizing stage by diffusion alone. Hydration resistance and activation energy were reduced and hydration speed was accelerated.
基金This work was supported by the National Key R&D Program of China(2019YFB2204500).
文摘Two-dimensional black phosphorus(2D BP),well known as phosphorene,has triggered tremendous attention since the first discovery in 2014.The unique puckered monolayer structure endows 2D BP intriguing properties,which facilitate its potential applications in various fields,such as catalyst,energy storage,sensor,etc.Owing to the large surface area,good electric conductivity,and high theoretical specific capacity,2D BP has been widely studied as electrode materials and significantly enhanced the performance of energy storage devices.With the rapid development of energy storage devices based on 2D BP,a timely review on this topic is in demand to further extend the application of 2D BP in energy storage.In this review,recent advances in experimental and theoretical development of 2D BP are presented along with its structures,properties,and synthetic methods.Particularly,their emerging applications in electrochemical energy storage,including Li−/K−/Mg−/Na-ion,Li–S batteries,and supercapacitors,are systematically summarized with milestones as well as the challenges.Benefited from the fast-growing dynamic investigation of 2D BP,some possible improvements and constructive perspectives are provided to guide the design of 2D BP-based energy storage devices with high performance.
基金Project supported by the National Key R&D Program of China(Grant No.2017YFB0305800)
文摘The band structure, density of states, optical properties, carrier mobility, and loss function of graphene, black phosphorus（BP）, and molybdenum disulfide（MoS_2） were investigated by the first-principles method with the generalized-gradient approximation. The graphene was a zero-band-gap semiconductor. The band gaps of BP and MoS_2 were strongly dependent on the number of layers. The relationships between layers and band gap were built to predict the band gap of few-layer BP and MoS_2. The absorption showed an explicit anisotropy for light polarized in（1 0 0） and（0 0 1） directions of graphene, BP,and MoS_2. This behavior may be readily detected in spectroscopic measurements and exploited for optoelectronic applications. Moreover, graphene（5.27 × 10~4 cm^2·V^（-1）·s^（-1））, BP（1.5 × 10~4 cm^2·V^（-1）·s^（-1））, and MoS_2（2.57×102 cm2·V-1·s-1）have high carrier mobility. These results show that graphene, BP, and MoS_2 are promising candidates for future electronic applications.
基金the National Key Research and Development Project of China(No.2016YFD0200800)the National Natural Science Foundation of China(No.41571226).
文摘In order to reveal the mechanism of silicon(Si)fertilizer in improving nitrogen(N)and phosphorus(P)nutrient availability in paddy soil,we designed a series of soil culture experiments by combining application of varying Si fertilizer concentrations with fixed N and P fertilizer concentrations.Following the recommendations of fertilizer manufacturers and local farmers,we applied Si in concentrations of 0,5.2,10.4,15.6,and 20.8μg/kg.At each concentration of added Si,the availability of soil N and P nutrients,soil microbial activity,numbers of ammonia-oxidizing bacteria and P-decomposing bacteria which means that the organic P is decomposed into inorganic nutrients which can be absorbed and utilized by plants,and urease and phosphatase activity first increased,and then decreased,as Si was added to the soil.These indicators reached their highest levels with a Si application rate of 15.6μg/kg,showing values respectively 19.78%,105.09%,8.34%,73.12%,130.36%,28.12%,and 20.15%higher than those of the controls.Appropriate Si application(10.4 to 15.6µg/kg)could significantly increase the richness of the soil microbial community involved in cycling of N and P nutrients in the soil.When the Si application rate was 15.6μg/kg,parameters for characterizing microbial abundance such as sequence numbers,operational taxonomic unit(OTU)number,and correlation indices of microbial community richness such as Chao1 index,the adaptive coherence estimator(ACE)index,Shannon index,and Simpson index all reached maximum values,with amounts increased by 14.46%,10.01%,23.80%,30.54%,0.18%,and 2.64%,respectively,compared with the control group.There is also a good correlation between N and P mineralization and addition of Si fertilizer.The correlation coefficients between the ratio of available P/total P(AP/TP)and the number of ammonia-oxidizing bacteria,AP/TP and acid phosphatase activity(AcPA),AP/TP and the Shannon index,the ratio of available N/total amount of N(AN/TN)and the number of ammoniated bacteria,and AN/TN and AcPA were 0.9290,0.9508,0.9202,0.9140,and 0.9366,respectively.In summary,these results revealed that enhancement of soil microbial community structure diversity and soil microbial activity by appropriate application of Si is the key ecological mechanism by which application of Si fertilizer improves N and P nutrient availability.
文摘The structure ofV2O5-P2O5-Sb2O3-Bi2O3glass and its state of crystallization were studied by means of infrared spectroscopy and X-ray diffraction analysis. The results indicate that, in this glass, V and P exist mainly in the form of a single-stranded linear （VO3）n and an isolated （PO4） tetrahedral with no double bond. Partial V and P are connected through O, forming an amorphous structure of layered vana- dium phosphate. Trivalent Sb3＋ and Bi3＋ open the V=O bond and appear in interlayers, so a weak three-dimensional structure is connected successfully. Along with the substitution of Sb203 for partial V205 or that of P205 for partial V205, the network structure of the glass is rein- forced, and the crystallization is reduced.
文摘Reducing phosphorus (P) loads from soils to surface waters is necessary for solving the problem of eutrophication. Many industrial by-products have been shown to sorb appreciable amounts of dissolved P from solution and it has been proposed to use P sorption materials (PSMs) such as steel slag in landscape scale “filters” for trapping dissolved P in runoff. The objective of this study was to model the effect of retention time (RT) and P concentration on P sorption by steel slag and a surface modified slag in a flow-through system. Sorption of P onto steel slag and rejuvenated-modified steel slag was measured using a traditional batch isotherm and a flow-through setting at several RTs and P concentrations. Flow-through data were used to produce a model that estimated P sorption based on RT and P concentration. The model was tested on a pilot-scale pond filter consisting of the same slag materials. For both the materials, flow-through tests indicated an increase in RT increased P removal efficiency but decreased the total amount of P removed at saturation. The Langmuir model developed from batch isotherms overestimated and underestimated P sorption in normal and rejuvenated slag respectively, relative to flow-through. Normal and rejuvenated slag removed 38 and 36% of P in the pilot-scale pond filter after 2 weeks of pumping. The Langmuir equation poorly predicted P sorption in the pond filter while the flow-through model produced reasonable estimates. Results suggest that flow-through methodology is necessary for estimating P sorption in the context of landscape P filters.
