Pure Phosphorus Research Articles

Simultaneous noninvasive ultrasensitive detection of prostate specific antigen and lncRNA PCA3 using multiplexed dual optical microfibers with strong plasmonic nanointerfaces

Low accuracy of diagnosing prostate cancer (PCa) was easily caused by only assaying single prostate specific antigen (PSA) biomarker. Although conventional reported methods for simultaneous detection of two specific PCa biomarkers could improve the diagnostic efficiency and accuracy, low detection sensitivity restrained their use in extreme early-stage PCa clinical assay applications. In order to overcome above drawbacks, this paper herein proposed a multiplexed dual optical microfibers separately functionalized with gold nanorods (GNRs) and Au nanobipyramids (Au NBPs) nanointerfaces with strong localized surface plasmon resonance (LSPR) effects. The sensors could simultaneously detect PSA protein biomarker and long noncoding RNA prostate cancer antigen 3 (lncRNA PCA3) with ultrahigh sensitivity and remarkable specificity. Consequently, the proposed dual optical microfibers multiplexed biosensors could detect the PSA protein and lncRNA PCA3 with ultra-low limit-of-detections (LODs) of 3.97 × 10−15 mol/L and 1.56 × 10−14 mol/L in pure phosphorus buffer solution (PBS), respectively, in which the obtained LODs were three orders of magnitude lower than existed state-of-the-art PCa assay technologies. Additionally, the sensors could discriminate target components from complicated physiological environment, that showing noticeable biosensing specificity of the sensors. With good performances of the sensors, they could successfully assay PSA and lncRNA PCA3 in undiluted human serum and urine simultaneously, respectively. Consequently, our proposed multiplexed sensors could real-time high-sensitivity simultaneously detect complicated human samples, that providing a novel valuable approach for the high-accurate diagnosis of early-stage PCa individuals.

Characterization Of Black Phosphorous Synthesized Via Ball-Milling Technique for The Effect of Milling Media and Time

Black phosphorus (BP), a unique arm-chair structure 2D material named for its distinctive black colour has been known to have intriguing properties include high energy storage and energy band-gap capabilities. BP is synthesized from the red phosphorus by using the ball-milling technique as an alternative to the existing complicated method which involves hazardous white phosphorus, high-temperature, and high-pressure conditions. Hence, we investigated and compared the effects of using alumina, stainless steel, and agate media on BP's physical and structural properties. The effects of milling time were performed afterward by using stainless-steel media for 1 h to 5 h. The ball-milling process at 450 rpm for 5 h in stainless steel media has transformed the coarse red powder into a dark black colour fine powder. The XRD analysis on the as-prepared powder revealed the existence of pure and crystalline black phosphorus. The Raman analysis indicated the apparent existence of BP structure synthesized. Observation of the FESEM images showed the BP existed with nanosized and flaky-shaped microstructure.

Greenhouse gas emission and energy analysis of vetch (Vicia sativa L.) cultivation

BackgroundAgricultural production accounts for a major share of global energy consumption and greenhouse gas emissions (GHG). However, the information on energy use and GHG emissions from various crops is contradictory. Climate change is expected to increase the GHG emission from different crops; therefore, selection of the crops with lower GHG emission could be helpful in reducing the emission and energy consumption. A major focus of energy policy should be on improving energy efficiency. Saving money and lowering GHG emissions are only two benefits of using energy efficiently. However, these are unknown for the vetch cultivation in Siirt province of Turkey. MethodsThis study investigated energy consumption efficiency and GHG emissions of vetch (Vicia sativa L.) production under dry circumstances in Siirt province, Turkey during 2021. Seed rate was kept 120 kg/ha in the current study. The amount of fertilizer applied was 92.0 kg/ha pure phosphorus and 36.0 kg/ha pure nitrogen. To calculate the energy efficiency of vetch production in Siirt, energy inputs and energy outputs were computed. ResultsThe energy intake and output were 8205.02 MJ/ha and 90388.56 MJ/ha, respectively. The energy inputs were: 37.1 % diesel fuel energy, 31.2 % fertilizer energy, 21.2 % seed energy, 9.6 % equipment energy, and 0.9 % labor energy. The results revealed that energy consumption efficiency was 11.02, specific energy was 0.34 MJ/kg, energy efficiency was 2.90 kg/MJ, and net energy was 82183.54 MJ/ha in vetch production. Total GHG emissions from vetch production was 205.19 kgCO2-eq ha−1, with diesel fuel accounting for the lion's share (72.88 %). Diesel fuel was followed by the consumption of nitrogen fertilizer (26.33 %), phosphorous (0.47 %) and machinery (0.42 %). Additionally, GHG ratio was 0.009 kg CO2-eq kg−1 in vetch production. ConclusionIt is concluded that encouraging the farmers to produce vetch as an alternative to the production of conventional forage crops and rotation in fodder production will be beneficial. It will reduce GHG emissions with lesser energy consumption.

An Ontology-Based Automation System

This paper presents an ontology-based approach to benefit automatic fertilization management for citrus orchards located in mountainous region. The core of the fertilization approach is the citrus fertilization ontology, which covers knowledge about citrus fertilizers and fertilization application. Specially, our approach can provide not only the yearly fertilization quantities of required pure nitrogen, phosphorus, and potassium according to their disease symptoms, but also the suitable fertilizing recommendations for the citrus orchards with different soil properties. The current version of the ontology (ver. 2.9.10) contains 103 classes, 34 properties, 800 instances, which are defined by 3056 RDF triples and is evaluated by using 90 competency questions. Furthermore, we run experiments with our proposal targeting at four citrus orchards in Chongqing, and compare its outputs with the reference values advised by the agri-professionals of citrus planting.

Synthesis and flame inhibition efficiency of a novel Fe-based metal complex with phosphorus-containing structure

Owing to the increased depletion risk and cost of phosphate mines, the demand for low phosphorus or ecological phosphorus flame inhibitor is increasing. This study reports an experimental exploration of the combustion inhibition efficiency of bio-based transition metal complex materials containing iron and phosphorus, namely, iron @ phosphorus complex (Fe-PMC). The aim is to develop a new type of flame inhibitor with an iron-phosphorus interaction effect to replace pure phosphorus extinguishing agents. The synthesis of Fe-PMC was characterized by Fourier-transform infrared spectroscopy, X-Ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscope. The Fe-PMC (ⅰ) is the mesh porous structure connected by the accumulation of small particles, (ⅱ) is an amorphous structure with many binding sites exposed and excellent interface compatibility, (ⅲ) contains no chloride ions. Suppression tests and thermogravimetric measurements indicate that (ⅰ) Fe-PMC has a higher combustion inhibition ability than MIL-53 containing only iron, especially at low concentrations, (ⅱ) Fe-PMC reduces the laminar flame velocity of cellulose, (ⅲ) Fe-PMC greatly reduces flame temperature. The activation energy (E), pre-exponential factor (A) and char yield (Y) of cellulose pyrolysis were determined by kinetic analysis. It concluded that MIL-53 and Fe-PMC produce combustion inhibition mainly in the solid phase. These findings will contribute to the development of a flame inhibitor with low or no phosphorus and better performance.

Low-Cost Electrocatalytic Layers for Hydrogen Evolution Reaction Based on Nickel and Cobalt Phosphides: Fabrication Via Codeposition-Annealing Route and XPS Characterization

In an attempt to mitigate the effects of climate changes, modern societies are facing a revolution in energy supply. Future economy will be increasingly dominated by carbon-free and renewable energy sources. In this context, hydrogen will play a fundamental role in the energy transition from fossil to green sources. It offers the possibility to smooth the intermittency typical of many renewable energy sources and it constitutes an ideal complement for batteries in the transport sector. Hydrogen can be easily produced employing water electrolysis, stored in large amounts and subsequently re-electrified in fuel cells. Efficient water electrolysis, however, makes use of noble metal electrocatalysts to lower the overpotential required for the Hydrogen Evolution Reaction (HER) to take place. Due to the limited availability and consequent high cost of noble metals, research is currently focusing on the development of low-cost alternative catalytic materials. One of the most studied electrocatalytic compounds are transition metal phosphides [1]. These materials present remarkable advantages over commonly used Pt based catalysts: comparable performances, lower cost, high abundancy and ease of manufacturing.In the present work, transition metal phosphides were fabricated through a simple and costless codeposition-annealing process. Amorphous Ni-P and Co-P alloys were codeposited with red phosphorus particles and subsequently annealed [2]. The annealing step was applied to promote the formation of intermetallics through interdiffusion between pure phosphorus particles and the metallic matrix. As a result, different phase pure metal phosphides were obtained. The most important advantage of this methodology is the possibility to overcome the compositional limit typical of electrodeposited phosphorus-based alloys. Elemental phosphorus codeposition allows to reach P concentrations higher than 50 % at., whereas simple Ni-P solid solution electrodeposition is compositionally limited to 25 % at. Enhancing P content is fundamental to obtain phosphorus rich compounds like Ni2P and Co2P, which are characterized by high catalytic activities for HER [3]. Furthermore, the technique allows to confine elemental P inside the coating during the annealing step. This peculiarity strongly optimizes material usage and it limits the presence of gaseous phosphorus, which is typical of many phosphorization processes used in literature to obtain metal phosphides [4] and it can result into the formation of the unstable white P allotrope.Obtained nickel and cobalt phosphides were characterized with different techniques (SEM, XRD, EDS) to assess their morphology, phase structure and chemical composition. A special emphasis was placed on XPS characterization. Thanks to its ability to analyze the first superficial layers of the coatings, XPS was employed to determine the chemical state of the elements present on the surface of the electrocatalysts. Being electrocatalysis an interfacial phenomenon, this allowed to link material surface properties with observed electrocatalytic performances.The electrocatalytic HER activity and stability of the different transition metal phosphides were tested in 0.5 M H2SO4. In all cases, remarkable results were obtained, with the lowest overpotential obtained in the case of Co-P/P codeposition and subsequent annealing at 290 °C: 62 mV vs. RHE at a current density of 10 mA/cm2 in 0.5 M H2SO4 solution. This result is in line with the literature available on cobalt phosphides as electrocatalysts [5].[1] P. Xiao et al., Adv. Energy Mater. 5, 1500985 (2015)[2] R. Bernasconi et al., ACS Appl. Energy Mater. 3(7), 6525–6535 (2020)[3] A. R. J. Kucernak et al., J. Mater. Chem. A 2, 17435 (2014)[4] X. Wang et al., Angew. Chem. 54(28), 8188 (2015)[5] Saadi et al., J. Phys. Chem. C 118(50), 29294–29300 (2014)

Nickel and Cobalt Phosphides Fabricated through a Codeposition-Annealing Technique As Low-Cost Electrocatalytic Layers for Efficient Hydrogen Evolution Reaction

In the perspective of sustainable development, future economy will be increasingly dominated by carbon-free and renewable energy sources. In this context, hydrogen will play a fundamental role in the energy transition from fossil to green sources. Hydrogen can be easily produced employing water electrolysis, stored in large amounts and subsequently re-electrified in fuel cells. It offers the possibility to smooth the intermittency typical of many renewable energy sources and it constitutes an ideal complement for batteries in the transport sector. Efficient water electrolysis, however, makes use of noble metal electrocatalysts to lower the overpotential required for the Hydrogen Evolution Reaction (HER) to take place. Due to the limited availability and consequent high cost of noble metals, research is currently focusing on the development of low-cost alternative catalytic materials. One of the most studied electrocatalytic compounds are transition metal phosphides [1]. These materials present remarkable advantages over commonly used Pt based catalysts: lower cost, high abundancy and ease of manufacturing. In many cases, phosphides offer performances comparable to the noble metal electrocatalysts.In the present work, transition metal phosphides were fabricated through a simple and costless codeposition-annealing process. Amorphous Ni-P and Co-P alloys were codeposited with red phosphorus particles and subsequently annealed. The annealing step was applied to promote the formation of intermetallics and the interdiffusion between pure phosphorus particles and the metallic matrix. As a result, different phase pure metal phosphides were obtained. The most important advantage of this methodology is the possibility to overcome the compositional limit typical of electrodeposited phosphorus-based alloys [2]. Elemental phosphorus codeposition allows to reach P concentrations higher than 50 % at., whereas simple Ni-P solid solution electrodeposition is compositionally limited to 25 % at. Enhancing P content is fundamental to obtain phosphorus rich compounds like Ni2P and Co2P, which are characterized by high catalytic activities for HER [3]. Another interesting benefit of the technique presented is the confinement of elemental P inside the coating during the annealing step. This peculiarity strongly optimizes material usage and it limits the presence of gaseous phosphorus, which is typical of many phosphorization processes used in literature to obtain metal phosphides [4] and it can result into the formation of the unstable white P allotrope.Specifically, Ni-P and Co-P were codeposited with red P particles and process conditions were optimized to maximize elemental P particles concentration. Annealing temperature and duration were varied to investigate their influence on final electrocatalytic perfrormances. Characterization techniques like XRD, SEM, EDS, cross-sectional analysis and XPS were used to determine phase composition of the materials obtained and to characterize their morphology. The electrocatalytic HER activity and stability of the different transition metal phosphides were tested in 0.5 M H2SO4. In all the cases, remarkable results were obtained, which matched up well with present existing literature where similar electrocatalysts have been fabricated through different methods [5]. The lowest overpotential was obtained in the case of Co-P/P codeposition and subsequent annealing at 290 °C: 62 mV vs. RHE at a current density of 10 mA/cm2 in 0.5 M H2SO4 solution.[1] P. Xiao et al., Adv. Energy Mater. 5, 1500985 (2015)[2] R. L. Zeller and U. Landau, J. Electrochem. Soc. 139(12), 3464 (1992)[3] A. R. J. Kucernak et al., J. Mater. Chem. A 2, 17435 (2014)[4] X. Wang et al., Angew. Chem. 54(28), 8188 (2015)[5] Z. Pu et al., Chem.Mater. 26(15), 4326 (2014)

High Yield Synthesis of Violet Phosphorus Crystals

Violet phosphorus is the most stable phosphorus allotrope with a layered structure. The corresponding violet phosphorene, a more stable two-dimensional semiconducting structure than black phosphorene, is a promising two-dimensional material for electronic and optoelectronic devices. The synthesis of violet phosphorus is the key factor to its experimental research. However, no clear evidence has been reported for the synthesis of violet phosphorus since its first proposal in 1865. The violet phosphorus was even debated to be a metastable intermediate phase. Until recently, the violet phosphorus crystals have just been successfully produced and exfoliated to give violet phosphorene. High yield synthesis of highly crystalline and pure violet phosphorus is crucial for the further exploration of violet phosphorus and phosphorene. In this work, highly crystalline and pure violet phosphorus crystals have been produced with a yield as high as 80%. The vapor transport, nucleation, crystal growth conditions, and synthesis mechanism have been studied to obtain violet phosphorus instead of black phosphorus. The mixture of transport agents and amorphous red phosphorus was heated to 600 °C to form P–Sn–I vapor and transported to the cooler zone (580 °C). The phosphorus was separated out from the P–Sn–I composites after cooling down to 530 °C to form violet phosphorus nuclei. The nucleation time and further cooling time correspond to the amount and crystallinity of violet phosphorus crystals. The precipitation has been demonstrated to be SnI2 crystals with a space group of C2/m (12) after the growth of violet phosphorus crystals. The synthesis of highly crystalline and pure violet phosphorus with high yield provides the application possibility of violet phosphorus and phosphorene in mechanic, electronic, optoelectronic, catalysts, and medical fields.

Kinetic and mechanistic study of dye sorption onto renewable resource-based doped carbon prepared by a microwave-assisted method

ABSTRACT Herein, a facile synthesis of heteroatom doped biochar is reported. The material is characterized and analyzed in detail for its application as a low-cost adsorbent for removal of a toxic dye pollutant, Methylene Blue (MB), from aqueous solution. Synthesized material showed enhanced surface area compared to parent biochar (458 to802 m2g−1) The adsorbent’s performance is investigated using batch adsorption methods with experiments conducted at varying conditions of adsorbent dosage, initial dye concentration (50–500 mg/L), and pH (3–11). Adsorption of MB onto two different adsorbents such as biochar (BC) and doped BC, is fitted using Langmuir and Freundlich isotherms with the experimental data correlating most accurately with Langmuir modelling, indicating chemisorption mechanism of dye onto adsorbent. Maximum monolayer equilibrium adsorption from Langmuir equation is found to be 129.8 and 357.1 mg/g for pure BC and Phosphorus and Nitrogen co-doped BC (PNBC), respectively. Pseudo-first and -second order kinetic models are applied to investigate the adsorption mechanism of PNBC. Adsorption mechanism followed pseudo-second order model well, with correlation coefficients very close to 1. The results indicate that microwave-assisted heteroatom co-doped BC showed superior performance as adsorbent for the adsorption of MB dye from aqueous solution.

Transition Metal Phosphides Fabricated through a Codeposition-Annealing Technique As Electrocatalysts for Hydrogen Evolution Reaction

In the present work, transition metal phosphides were fabricated through a facile codeposition-annealing process. Pure red phosphorous particles were electrolytically codeposited with amorphous phosphorus containing alloys of general structure Me-P (with Me being a transition metal). A subsequent annealing step was applied to promote the formation of intermetallics and the interdiffusion between pure phosphorus particles and the metallic matrix. The main advantage of this approach is the possibility to easily obtain metal phosphides characterized by a very high P content, well beyond the limit typical of normal electrochemical processes involving induced codeposition of P [1, 2]. Another interesting benefit of the technique presented is the confinement of elemental P inside the coating during the annealing step. This strongly limits the presence of gaseous phosphorus, which is typical of different phosphorization processes used in literature to obtain metal phosphides [3]. Avoiding gaseous P is advantageous, since in specific conditions the formation of the highly dangerous white allotrope can take place. The use of P particles confined inside the coating is preferable also to phosphorization methods involving phosphine, an extremely poisonous gas commonly employed at lab level. The codeposition-annealing route described in the present work can be in principle applied to a number of transition metals for many different applications. One of the most attractive application for metal phosphides, however, is electrocatalysis for water splitting [4]. In this context, the codeposition-annealing technique was applied to the fabrication of Ni and Co phosphides, which can be used as catalytic substrates for Hydrogen Evolution Reaction (HER). These two materials present remarkable advantages over commonly used Pt based catalysts: lower cost, comparable performances and ease of manufacturing. Operatively, amorphous Ni-P and Co-P alloys were codeposited with P particles and subsequently annealed. As a result, different phase pure metal phosphides like Ni2P, Ni12P5, Co2P, Cu3P etc. were obtained after annealing. Characterization techniques like XRD, SEM (EDS), cross-sectional analysis and XPS were used to determine phase composition of the materials obtained and to characterize their morphology. Effect of annealing temperature and duration on phase composition were investigated as well. The electrocatalytic HER activity and stability of the different transition metal phosphides were tested in 0.5 M H2SO4. In all the cases, remarkable results were obtained, which matched up well with present existing literature where similar electrocatalysts have been fabricated through different methods [5]. For example, a Co2P electrocatalyst plated on copper and annealed at 290 °C exhibited excellent electrocatalytic activity for HER, showing a low overpotential of 62 mV at a current density of 10 mA/cm2 in 0.5M H2SO4 solution. [1] R. L. Zeller and U. Landau; J. Electrochem. Soc. 139 (12), 3464-3469 (1992) [2] A. Brenner; Electrodeposition of Alloys: Principles and Practice, Elsevier (2013) [3] X. Wang et al.; Angew. Chem. 54 (28), 8188-8192 (2015) [4] P. Xiao et al.; Adv. Energy Mater. 5 (24), 1500985 (2015) [5] Z.Pu et al.; Chem.Mater. 26 (15), 4326-4329 (2014)

Selective recovery of phosphorus as AlPO4 from silicon-free CFB-derived fly ash leachate

The prospect of phosphorus (P) recovery from siliceous fly ash was investigated. The phosphorus content in the pristine fly ash was 1.21%. Obtaining pure phosphorus products from fly ash is very challenging because of high concentration of other elements, silicon (Si) at 17.3% being the major contaminant. The fly ash was fractionated with sieve size of 125 μm to concentrate the phosphorus in the small-size fraction, which also facilitated the removal of 78% of silica (Si) in the solid phase. The fractionated fly ash was treated with 8 M HCl in order to remove 98% of Si by aging (5 h) of leachate until precipitation of Si-gel, and a phosphorus-rich solution is obtained. Iron (Fe) is also considered an impurity in the recovered P-product and its co-precipitation is prevented by the use of EDTA as Fe-masking reagent at [EDTA]/[Fe] ratio of 1. About 70% of Fe is retained in the solution during recovery of phosphorus with aluminum at pH 4. Amorphous white solid was recovered containing 18.08% P, this is 15 times high than that in the pristine fly ash used as raw material in this recovery process.

Hydrothermal synthesis of red phosphorus @reduced graphene oxide nanohybrid with enhanced electrochemical performance as anode material of lithium-ion battery

Red phosphorus @reduced graphene oxide (P @rGO) nanohybrid was synthesized via a two-step hydrothermal process. The obtained P @rGO nanohybrid was characterized by TEM, SEM, Raman, XRD and XPS. It was found that the nano-scale red phosphorus encapsulated in the reduced graphene oxide and the existence of phosphorus promote the reduction of graphene oxide. The electrochemical performance of P @rGO nanohybrid as an anode material was investigated by galvanostatic charge/discharge, rate performance, cyclic voltammetry and AC impedance test. With increasing the mass of rGO, the electrochemical performance of P @rGO nanohybrid was significantly enhanced. The first discharge/charge specific capacity of the nanohybrid prepared at optimum condition (P:GO = 7:3) could achieve approximately 2400 mAh/g and 1600 mAh/g respectively and still retained ∼1000 mAh/g after 80 cycles and the coulombic efficiency maintained almost 100%. The enhancement in P @rGO nanohybrid was attributed to the introduction of graphene, which led to the elimination of volume effect and the enhancement of conductively of pure red phosphorus.

EPR of synthetic diamond heavily doped with phosphorus

In this work, diamond synthesized under high‐pressure high‐temperature (HPHT) conditions in the phosphorus‐carbon system with addition of aluminum has been studied by electron paramagnetic resonance (EPR). It is established that microcrystals with different defect concentrations are formed. Nitrogen‐phosphorus defects NP3 are observed in some microcrystals, although pure phosphorus paramagnetic centers NP8 and NP9 are detected in other microcrystals. The NP8 center has an electron spin S = 1/2, gxx = gyy = 2.0016, gzz = 2.0048, and hyperfine structure (HFS) of one phosphorus atom Axx = Ayy = 3.2 mT, Azz = 5.6 mT. The NP9 center has an electron spin S = 1/2, gxx = gyy = 2.0038, gzz = 2.0030, and HFS of two inequivalent phosphorus atoms A(P1)xx = A(P1)yy = 8.8 mT, A(P1)zz = 13.6 mT, A(P2)xx = A(P2)yy = 2.2 mT, A(P2)zz = 1.4 mT. The structures of the NP8 and NP9 centers are discussed. Concentration of phosphorus impurity in some microcrystals is high enough to detect conductivity electrons. Subsequent annealing of the samples at 2273 K leads to the disappearance of the NP3, NP8, and NP9 spectra; the NP4 spectrum is observed.

Assessment of stand types for phosphorus acquisition and internal utilization efficiency in a desert plant Blepharis sindica (T. Andres.)

Impact of stand types (monoculture and polyculture) on phosphorus acquisition efficiency and their subsequent internal utilization efficiency were determined at species level, in a seratonious arid endangered plant, Blepharis sindica. At pure stand phosphorus acquisition efficiency (PAE) was recorded higher during pulse event (rain) while at mixed stand it was recorded more during non-pulse event (summer). This indicates that at pure stand this species rapidly full-fill their P demand during high soil P availability (pulse event), but at mixed stand due to presence of other life forms this species have adjusted their P acquisition efficiency during non-pulse (low soil P), when other associate probably not able to do this. Ordination analysis shows lack of correlation between PAE and PUTIL, indicates that selection of one of these should not affect the other. Regression analysis between P variables and community factors revealed that at species level dominance of B. sindica reflects with its higher P acquisition efficiency; however as the community diversity (Richness, Shannon and Weaver index and evenness) increases the P internal utilization and PUE were inhibited. Thus it can be concluded that both P internal utilization and PUE of B. sindica are largely influenced with temporal factors (Increase and decrease of community diversity during pulse and non-pulse events, respectively). This plant achieved their effective nutrient use through temporal partitioning, through which it full-fill their P requirements during low resource availability (non-pulse event). Both soil organic carbon and carbon to nitrogen ratio supports PAE in linear fashions. Similarly soil pH also monotonically supports PAE, while soil organic carbon monotonically inhibits QUTIL. The greater nutrient uptake and uptake efficiency in a pure stand reflects narrow niche width of B. sindica and hence it can be conclude that the impact of life-form diversity on nutrient use efficiency is not a static phenomenon.

Modification and use of biochar from wheat straw (Triticum aestivum L.) for nitrate and phosphate removal from water

Surface modification can improve biochar adsorption capacity. Biochars were produced from wheat straw through low-temperature pyrolysis at approximately 450°C, activated with hydrochloric acid (HCl), and coated with iron (FeCl3·6H2O) of different amounts. Results showed that activation with HCl and coating with iron can significantly increase biochar adsorption capacity. The increase after HCl treatment was very small at a high ratio of iron to biochar. The optimal ratio of iron to biochar for iron-coated biochar was 0.70. Adsorption capacity was calculated based on the amount of pure nitrogen or phosphorus. The maximum adsorption capacities were 2.47 and 16.58 mg g−1. The most effective pH values for nitrate and phosphate removal were 3 and 6, respectively. The active substance of the optimal-modified biochar (OMB) was amorphous FeOOH, and the structure [C–Fe(OH2)5](s)3+ was the hydroxylated mineral surface of OMB in a water solution. The equilibrium pH of the adsorption solution was lower than 7 even when the initial pH of the solution was 11 because [C–Fe(OH2)5](s)3+ changed into [C–Fe(OH2)4(OH)](s)2+, [C–Fe(OH2)3(OH)](s)+, and H3O+ with the increase in pH. Adsorption experiments showed that OMB can be utilized to remove nitrate and phosphate from water.

Influence of arbuscular mycorrhizal fungi and different levels of phosphorus on the growth of corn in water stress conditions

In this research the effects of mycorrhizal fungi and different levels of phosphorous chemical fertilizers on yield and yield components of corn under three levels of irrigation (60,120 and180 mm) were studied. This experiment was performed in a split factorial design with four replications. Irrigation were placed in the main plots at different pure phosphorus levels (0, 60 and 120 kg/ha) and mycorrhizal fungi (0 and 6 g per seed) were placed in the subplots. The results indicated that mycorrhizal fungi had significance effects on the yield and yield components of corn. The highest grain yield (5045 kg/ha) and number of seed per row (41) were obtained in treatments irrigation (60 mm), phosphorus (60 g/m2) and mycorrhiza (6 g per seed), while this treatment had not significance difference with irrigation (120 mm )× phosphorus (60 g/m2) × mycorrhiza (6 g per seed). The highest 1000 grain weight (157.75 g) were obtained in treatments irrigation (60 mm) × phosphorus (60 g/m2) × mycorrhiza (6 g per seed) with irrigation (60 mm) × phosphorus (120 g/m2) × mycorrhiza (6 g per seed). However, such mycorrhizal efficiency revealed a decreasing trend with increasing use of phosphorous chemical fertilizers. Moreover, under water stress, mycorrhizal inoculation improved most of the measured indexes. This kind of bio-fertilizer can therefore, have an important key role in agriculture of arid and semi-arid climates. Key words: Mycorrhizal symbiosis, phosphorus, water stress, corn.

Atomistic modeling of an impurity element and a metal–impurity system: pure P and Fe–P system

An interatomic potential for pure phosphorus, an element that has van der Waals, covalent and metallic bonding character, simultaneously, has been developed for the purpose of application to metal–phosphorus systems. As a simplification, the van der Waals interaction, which is less important in metal–phosphorus systems, was omitted in the parameterization process and potential formulation. On the basis of the second-nearest-neighbor modified embedded-atom method (2NN MEAM) interatomic potential formalism applicable to both covalent and metallic materials, a potential that can describe various fundamental physical properties of a wide range of allotropic or transformed crystalline structures of pure phosphorus could be developed. The potential was then extended to the Fe–P binary system describing various physical properties of intermetallic compounds, bcc and liquid alloys, and also the segregation tendency of phosphorus on grain boundaries of bcc iron, in good agreement with experimental information. The suitability of the present potential and the parameterization process for atomic scale investigations about the effects of various non-metallic impurity elements on metal properties is demonstrated.

Effects of mycorrhizal symbiosis and different levels of phosphorus on yield, macro and micro elements of Zea mays L. under water stress condition

Nowadays, Mycorrhizal fungi are widely used due to their symbiosis relation with roots of so many plants. These fungi, by supplying some of plant nutritional and water requirements, have a key role in all ecosystems. In this research the effects of mycorrhizal fungi and different levels of phosphorous chemical fertilizers on yield and nutrient uptake under three levels of irrigation were studied. This experiment was performed in fully randomized blocks and as a split factorial design with four replications in which different irrigation levels (A1, A2, A3) (60.120.180 mm) were placed in the main plots while different phosphor levels including P1=0 kg/ha, P2=60 kg/ha and P3=120 kg/ha of pure phosphorus were placed in the subplots. Half of these subplots inoculated by mycorrhizal fungi and the others regarded as uninoculated ones in inoculated sub plots, at seed sowing, 6 g of Mycorrhizal inoculums were placed 3 cm under the each seed. The results indicated that the effects of Mycorrhizal inoculation were statistically significant and positive on measured characteristics. Among triple interactions irrigation/chemical phosphorus/mycorrhizal inoculation had significant effects (P<0.05, 5045 kg/ha) on grain yield and (P<0.01) on Phosphorus concentration. Highest grain yield and other yield component were in A1P2G2 treatment. Results showed that in moderate water stress, by using proper amount of chemical phosphorus and mycorrhizal inoculation can compensate decrease in grain yield. Other treatments had significant difference with A2P2G2 which means by increasing water stress, increasing or decreasing amount of chemical phosphorus and without mycorrhizal inoculation grain yield of corn will decrease significantly. However, such mycorrhizal ability can help us to decrease amount of phosphorus chemical fertilizes in corn growth. Moreover, under water stress, mycorrhizal inoculation improved most of measured indexes. Therefore this kind of biofertilizer can have an important key role in agriculture of arid and semiarid climates. Key words: Mycorrhizal symbiosis, phosphorus, water stress, corn.

Activated-phosphorus as new electrode material for Li-ion batteries

An innovative concept of activation of electrode materials for Li-ion batteries is proposed through the preparation of carbon-phosphorus (P/C) composites. Carbon-encapsulated phosphorus composites can be successfully prepared via a simple route by the vaporization–condensation of red phosphorus onto mesoporous carbon. Surface area measurements and Raman spectroscopy were used for the characterization of the P/C composites, which were then tested as anode materials in Li-ion batteries showing enhanced electrochemical properties. In contrast to what is observed for pure unsupported phosphorus, Li storage in P/C composite occurs through the reversible formation of Li 3P during the discharge process, as clearly evidenced by in situ XRD, leading to capacities greater than 900 mAh g −1 after 20 cycles.

Inhomogeneous broadening of phosphorus donor lines in the far-infrared spectra of single-crystalline SiGe

The origins of line broadening in the far-infrared spectrum of phosphorus donors in SiGe are investigated. Using a combination of Fourier transform infrared (FT-IR) spectroscopy and time-resolved pump-probe measurements, we show that the line shapes are dominated by inhomogenous broadening. Experimental FT-IR absorbance spectra measured in the temperature range 6--150 K are presented for three different Ge contents. Additional spectra of pure phosphorus doped silicon recorded under similar experimental conditions are presented and compared with the SiGe results. We propose a simple quantitative model to simulate the line broadening in our experimental spectra. Our model takes into account the compositional variations in the random SiGe binary alloy and its effect on the permittivity of the environment around each donor. We also show that the addition of small amounts Ge to Si single crystals has little detrimental effect on the lifetime of the excited infrared electronic energy levels, despite the observed line broadening.