Effects of nitrogen and phosphorus additions on soil microbial community structure and ecological processes in the farmland of Chinese Loess Plateau

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.

Self‑Healing Dynamic Hydrogel Microparticles with Structural Color for Wound Management

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.

Quantum Chemical Calculations of the Structure,Property and Stability of Penta-coordinated Carbonium Ions Derived from Normal Butane

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.

Crystal Structures and Antimicrobial Activity of Two Phosphorus Compounds

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.

Synthesis and Crystal Structure of a New Penta-coordinated Cu(Ⅱ) Complex:Cu(C_(17)H_(13)F_3O_3)_2·C_5H_5N

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.

Effect of Waterscape Structures on Nitrogen and Phosphorus Removal Efficiency in Revetment Wetland System

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.

Solidification Structure of Low Carbon Steel Strips with Different Phosphorus Contents Produced by Strip Casting

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.

Synthesis and Structural Characterization of Organophosphorus Ylide-1-(3-nitrophenyl)-2-(triphenyl phosphoranylidene)ethanone

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）.

Amorphous Sn(HPO_(4))_(2)-derived phosphorus-modified Sn/SnO_(x) core/shell catalyst for efficient CO_(2) electroreduction to formate

Simultaneously achieving high activity,selectivity and stability for electrochemical CO_(2)reduction reaction(CO_(2)RR)remains great challenges.Herein,a phosphorus-modified Sn/Sn Oxcore/shell(P-Sn/SnO_x)catalyst,derived from in situ electrochemical reduction of an amorphous Sn(HPO_(4))_(2) pre-catalyst,exhibits high CO_(2)RR performance.The total Faradaic efficiency(FE)of C_(1) products is close to 100%in a broad potential range from-0.49 to-1.02 V vs.reversible hydrogen electrode,and a total current density of 315.0 m A cm^(-2)is achieved.Moreover,the P-Sn/SnO_(x) catalyst maintains a formate FE of~90%for 120 h.Density functional theory calculations suggest that the phosphorus-modified Sn/SnO_(x) core/shell structure effectively facilitates formate production by enhancing CO_(2)adsorption and improving free energy profile of formate formation.

Leaching behavior and microstructure of phosphorus in converter slag

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.

Metal-free two-dimensional phosphorene-based electrocatalyst with covalent P-N heterointerfacial reconstruction for electrolyte-lean lithium-sulfur batteries

The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.

Hydration Kinetics of Phosphorus Slag-cement Paste

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.

Two‑Dimensional Black Phosphorus Nanomaterials:Emerging Advances in Electrochemical Energy Storage Science

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.

Electronic, optical property and carrier mobility of graphene, black phosphorus, and molybdenum disulfide based on the first principles

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.

Structure of V_2O_5-P_2O_5-Sb_2O_3-Bi_2O_3 glass

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.

Predicting Phosphorus Sorption onto Steel Slag Using a Flow-through approach with Application to a Pilot Scale System

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.

Penta-coordinated phosphorus structure analysis on kinases

In this paper, based on the known crystal structures of Square Pyramid (SP) and Trigonal Bipyramid (TBP) penta-coordinated phosphorus compounds containing amino acid side chains, such as amino, carboxyl, hydroxyl or thiol, a software designed to survey the P(5)-Structure of phosphorylated proteins. By this software, it was found that 382 of 398 phos- phorus-related kinases (96%) from current PDB could go through the penta-coordinated phos- phorus transition state or intermediate. For example, in protein 1HE8, amino group in Lysine16 was within 3.58 ?from the phosphorus atom, and a potential TBP structure consisting GNP2 and NZ could be overlapped with an authentic TBP with an RMSD value of 0.71 ?.

Synthesis and Crystal Structure of Cis 2-(6- Chloro-3-pyridylmethylamino)-4-chlorophenyl- 5,5-dimethyl-1,3,2-dioxaphosphinane 2-Oxides

The crystal structure of the title compound (C17H19Cl2N2O3P, Mr = 401.21) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 6.1648(6), b = 19.943(2), c = 15.268(2) ?, β = 99.220(2)°, V = 1852.8(3) ?3, Z = 4, Dc = 1.438 g/cm3, F(000) = 832, μ(MoKα) = 0.456 mm-1, the final R = 0.0622 and wR = 0.1586 for 3986 observed reflections (I > 2σ(I)). X-ray analysis reveals that the product is a thermodynamically stable cis isomer. The intramolecular hydrogen bond N(2)–H(2A)…O(1) is observed in the title compound.

Synthesis and Crystal Structure of [K(2,2,2-crypt)]_2HP_(11)

[K（2,2,2-crypt]2HP11 has been prepared from the reaction of K3P11 with the mixed ethylenediamine/2,2,2-crypt solution. The crystal structure was determined by singlecrystal X-ray diffraction. The crystal is of tdgonal system, space group P^-3c1 with a = 12.068（2）, b = 12.068（2）, c = 22.319（6）A, V = 2815.0（10）A^3, Dc = 1.384 g/cm^3, C36h73K2N4O12P11, Mr = 1172.85, F（000） = 1232,μ = 0.536 mm^-1, Z= 2, R = 0.0678 and wR = 0.2211 for 1763 observed reflections （I 〉 2σ（I））. In this compound, the P11 cluster has ideal 32-D3 symmetry, and the three-fold axis, corresponds to the crystallographic c axis. The （HP11）^2- anions are stable due to the completely sequestered alkali metal cations through only ion-ion interactions.

Synthesis and Crystal Structure of [K(18-Crown-6)]_3P_(11)·2en

The undecaphosphide anion in ethylenediamine/18-crown-6 solution is isolated as [K（18-crown-6）]3P11·2en 1. The crystal structure has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21 with α = 13.4731（7）, b = 16.1123（6）, c = 16.5117（9） A, β = 112.133（2）°, Y = 3320.3（3） A3, Dc = 1.371 g/cm^3, C40H88K3N4O18P11, Mr = 1371.11, F（000） = 1444,μ = 0.532 mm^-1, Z= 2, R = 0.0544 and wR = 0.1326 for 11423 observed reflections （I 〉 20（I））. The ＂naked＂ P11^3- ion is stabilized by two partly sequestered potassiums, The third partly sequestered potassium does not interact with the P atom （P（6）） but with two solvent molecules.