Effect of available phosphorus in paddy soils on phosphorus uptake of rice

Relation between available phosphorus in 6 types of paddy soil in, Human Province and its uptake by rices was studied by³²P tracing. The result indicated that the P uptake by rices varied with available P content in the paddy soils. When the content was high, the rice absorbed more P nutrient from the soil and decreased the P uptake from the P fertilizer, which showed a poor contribution of the P fertilizer to the rice yield increase, and vice versa. The recovery of the P fertilizer varied with the soil types. Ranked the first was in paddy soils derived from lacustrine deposite but little rice yield increased. While in paddy soils derived from limestone, the yield greatly increased although the recovery of P fertilizer was the lowest. Rice absorbed P nutrient during its whole growth duration. No matter the different uptake amount due to the P supply by the different soils, rice plant generally had the greatest P nutrient uptake from tillering stage to elongation stage, and along with the rise of the rices dry matter, amount of P uptake was gradually increased but the P content in unit dry matter was tended to decrease.     

Penta-coordinated phosphorus structure analysis on kinases

Phosphorus element was discovered in organismin the 17th century. In the past decades, it has beenfound that phosphorus plays crucial roles in many as-pects of bio-systems. For example, many biologicalprocesses are regulated by the phosphorylation anddephosphorylation of amino acid residues in proteins[1].However, there are still some unsolved problems[2],such as whether the process goes through a penta-co-ordinated phosphorus or a metaphosphate dianionicintermediate. The X-ray crystals struc…     

Influence of interface structure on mass transport in phase boundaries between different ionic materials

Abstract  Internal and external interfaces in solids exhibit completely different transport properties compared to the bulk. Transport parallel to grain or phase boundaries is usually strongly enhanced. Transport perpendicular to an interface is usually blocked, i.e., transport across an interface is often much slower. Due to the high density of interfaces in modern micro- and nanoscaled devices, a severe influence on the total transport properties can be expected. In contrast to diffusion in metal grain boundaries, transport phenomena in boundaries of ionic materials are still less understood. The specific transport properties along metal grain boundaries are explained by structural factors like packing densities or dislocation densities in the interface region. In most studies dealing with ionic materials, the interfacial transport properties are merely explained by the influence of space charge regions. In this study the influence of the interface structure on the interfacial transport properties of ionic materials is discussed in analogy to metallic materials. A qualitative model based on the density of misfit dislocations and on interfacial strain is introduced for (untilted and untwisted) phase boundaries. For experimental verification, the interfacial ionic conductivity of different multilayer systems consisting of stabilised ZrO₂ and an insulating oxide is investigated as a funtion of structural mismatch. As predicted by the model, the interfacial conductivity increases when the lattice mismatch is increased. Graphical abstract  

Plant uptake of radioactive corrosion products in a field study

The root uptake by wheat of three activation products (⁵⁷Co, ⁵⁴Mn and ⁶⁵Zn) was studied in a 3-year field experiment. The aim of the investigation was to calculate the soil–plant transfer factors of these nuclides and to verify the role played by different soil treatments (Ca and K) on the uptake. The uptake of ⁵⁴Mn and ⁶⁵Zn, relevant for the plant, was higher than that of ⁵⁷Co (physiologically unimportant). The temporal distribution of the uptake showed a decreasing trend, while the treatments containing Ca led to lower transfer factors for ⁵⁴Mn and ⁶⁵Zn, which varied between 0.67 and 3.68. The variations exhibited by the different nuclides were discussed, as well as the differences between the treatments.     

Influence of side chains assembly on the structure and transport properties of comb-like polysiloxanes in hydrocarbon separation

We have synthesized a number of comb-like polysiloxanes with linear, branched, cyclic and silicon-containing substituents; most of them are new and previously not studied polymers. The physicochemical properties of comb-like polysiloxanes have been systematically investigated. Differential-scanning calorimetry and wide-angle X-ray scattering data revealed the side-chain microphase assembly for polymers with linear aliphatic substituents, while the polymers with bulky substituents did not form a microphase. It is shown that the ratio of microphase in the polymer is greater, the closer the values of the thickness of the microphase layer and the length of the cross-link. The effect of the side-chain substituent on the hydrocarbon transport properties of comb-like polysiloxanes was studied. All synthesized polymers are promising as membrane materials for a vital process of hydrocarbon separation. This is associated with an increase in the solubility selectivity of n-butane/methane because the solubility coefficient of methane sharply decreases when long side chains are introduced into the polysiloxane. It was shown for the first time that microphase forming polymers have a significantly higher butane/methane selectivity (23.2–27.5) than polysiloxanes not forming a microphase (selectivity 12.3–20.0). The effect is demonstrated on polysiloxanes with various types of side substituents. It was revealed that for the comb-like polysiloxanes, the diffusivity selectivity and permselectivity are proportional to the fraction of the side-chain microphase in the polymer. With the increase in the hydrocarbon microphase share, the diffusion coefficient of the permanent gas methane is decreasing more rapidly than n-butane, which dissolves well in hydrocarbons and plasticizes polymer. Consequently, the polymers forming the microphase have a higher selectivity C₃₊/CH₄ in the separation of a multicomponent hydrocarbons mixture.     

Influence of chemical modification (bromination) on structure and charge transport in poly(N-vinylcarbazole)

Bromine has been randomly substituted in the 3 or 6 position of the pendant carbazole group of poly(N-vinylcarbazole) using N-bromosuccinimide in chlorobenzene solution. X-ray diffraction indicated that this substitution interferes with the interchain interactions in the amorphous polymer eliminating the unusual degree of chain parallelism and destroying the ability to crystallize. Charge carrier photogeneration and mobility measurements show that holes are still the majority carrier in the bromine-substituted polymer but both generation and mobility are substantially reduced compared to the unsubstituted polymer. It has not been possible to separate the influence of pendant group electronic structure from that of bulk chain conformation in this modification of the polymer photoconductive properties.     

Reaction of yeast inorganic pyrophosphatase with inorganic phosphate labeled with radioactive phosphorus

Conclusions The reaction of yeast inorganic pyrophosphatase with inorganic [p³²]phosphate forms a phosphorylated enzyme.     

Influence of nitrogen partial pressure on morphology,structure and transport properties of reactive sputtered polycrystalline TiN films

The surface morphology, structure and electrical transport properties of the polycrystalline TiN films fabricated using reactive sputtering at different N₂ partial pressures (P_N2) have been investigated systematically. The films grow with the preferred (200) orientation. The room-temperature resistivity first deceases, then slightly increases with the increase of P_N2. The minimum room-temperature resistivity is about 1.7 × 10⁻³ Ω cm at P_N2 = 0.5 Pa. The low temperature conductance mechanism turns from tunneling across the grain boundaries to variable-range hopping as P_N2 increases. The decreased density of states at E_F with the increase of N vacancies should be the reason for the increased resistivity of the films fabricated at different P_N2.     

Steric structure of heterocycles containing phosphorus

¹H and³¹P dynamic NMR, vibrational spectroscopy, and consideration of dipole moments have shown that 2-chloro-2-thiono-4,5;7,8-dibenzo(4,4-dimethyl-6,6-di-tert-butyl)-1, 3,2-dioxaphosphocene and its 2-ethoxy derivative are conformationally heterogeneous. The former exists as a three-component equilibrium mixture, and the latter as a two-component equilibrium mixture. In the chlorothiophosphate the boat-chair conformation predominates, with equatorial location of thiophosphoryl; next in frequency is boat-chair with axial orientation of P=S, and third is the deformed boat form. In the ethyl thiophosphate the preponderant form is the deformed boat with thiophosphoryl in the equatorial position.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2766–2772, December, 1990.     

Influence of nitrogen and phosphorus on thein situ bioremediation of trichloroethylene

Applied Biochemistry and Biotechnology - The US Department of Energy, Office of Technology Development, has supported a field-scalein situ demonstration of trichloroethylene (TCE) bioremediation at...     

Influence of the constraint of bridgehead structure on phosphorus reactivity in the 1-phosphabicyclo[3.2.1]octane system

Nucleophiles attack the methiodide of the 3,4-benzo derivative of the title system to displace the P-methyl group in peference to the benzylic moiety. The trigonal bipyramidal intermediates (as well as a stable dioxyphosphorane) appear to undergo rapid isomerization.     

Influence of magnetic forces on electrochemical mass transport

Enhancements of the order of 100% in the mass transport limited current for electrodeposition have been observed in magnetic fields of order 1 T. The effect of the field is to induce convection in the solution and it is equivalent to rotating the electrode or stirring the solution. In this communication, a quantitative comparison is made of the magnitude of various body forces which have been proposed to account for the experimentally observed effects, with a view to identifying the likely source of the field enhancement. When the magnetic field is uniform, the Lorentz force and the electrokinetic force both contribute significantly to the field enhancement.