486 research outputs found

    On the non-Riemannian quantity H in Finsler geometry

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    AbstractIn this paper, we study a new non-Riemannian quantity H defined by the S-curvature. We find that the non-Riemannian quantity is closely related to S-curvature. We characterize Randers metrics of almost isotropic S-curvature if and only if they have almost vanishing H-curvature. Furthermore, the Randers metrics actually have zero S-curvature if and only if they have vanishing H-curvature

    (6,6′-Dimeth­oxy­biphenyl-2,2′-di­yl)bis(diphenyl­phosphane) P,P′-dioxide dihydrate

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    In the title compound, C38H32O4P2·2H2O, the dihedral angle between the meth­oxy­phenol rings is 84.11 (7)°. O—H⋯O hydrogen bonds connect the water mol­ecules of crystallization with the main mol­ecule

    On Potassium Deficiency in Cotton– Disorder, Cause and Tissue Diagnosis

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    As modern cotton varieties including Bt (Bacillus thuringiensis) transgenic cotton are adopted and yield per unit area continues to increase, potassium deficiency is occurring with rising frequency in many cotton-growing countries. Symptoms of K deficiencies used to occur at the bottom of the plant on the older or mature leaves, but more recently described symptoms show up on young leaves near the top of the plant. Potassium deficiency induces numerous disorders in cotton, including decreased leaf area index, photosynthesis and plant biomass, but enhances specific leaf weight and earliness of maturity. Low supply and uptake of K, adoption of modern cotton varieties particularly Bt transgenic cotton, and environmental stress are obvious contributors to potassium deficiency. Single leaf photosynthesis (Pn) reduction results mainly from decreased stomatal conductance, low chlorophyl content, poor chloroplast ultrastructure, restricted saccharide translocation, and decreased synthesis of RuBP carboxylase under K deficient conditions. Canopy photosynthesis reduction in K-deficient plants is mainly attributed to both inhibited single leaf Pn rate and decreased leaf area index. Potassium concentrations in both blade and petiole of top fully expanded leaves on main stem are good indicators of K deficiency

    On Potassium Deficiency in Cotton– Disorder, Cause and Tissue Diagnosis

    Get PDF
    As modern cotton varieties including Bt (Bacillus thuringiensis) transgenic cotton are adopted and yield per unit area continues to increase, potassium deficiency is occurring with rising frequency in many cotton-growing countries. Symptoms of K deficiencies used to occur at the bottom of the plant on the older or mature leaves, but more recently described symptoms show up on young leaves near the top of the plant. Potassium deficiency induces numerous disorders in cotton, including decreased leaf area index, photosynthesis and plant biomass, but enhances specific leaf weight and earliness of maturity. Low supply and uptake of K, adoption of modern cotton varieties particularly Bt transgenic cotton, and environmental stress are obvious contributors to potassium deficiency. Single leaf photosynthesis (Pn) reduction results mainly from decreased stomatal conductance, low chlorophyl content, poor chloroplast ultrastructure, restricted saccharide translocation, and decreased synthesis of RuBP carboxylase under K deficient conditions. Canopy photosynthesis reduction in K-deficient plants is mainly attributed to both inhibited single leaf Pn rate and decreased leaf area index. Potassium concentrations in both blade and petiole of top fully expanded leaves on main stem are good indicators of K deficiency

    5-[2-(4-Acetyl­oxyphen­yl)ethen­yl]benzene-1,3-diyl diacetate

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    The title compound, C20H18O6, was prepared from resveratrol {systematic name: 5-[(E)-2-(4-hy­droxy­phen­yl)ethen­yl]ben­z­ene-1,3-diol}, which can be isolated from grapes, through triacetyl­ation with using acetic anhydride in pyridine. The two benzene rings are approximately coplanar, making a dihedral angle of 6.64 (14)°, and the three acet­oxy group are located on the same side of the plane. The skeleton of the compound resembles a table with three legs. In the crystal, mol­ecules are linked via C—H⋯O interactions, forming inversion dimers. These dimers are further linked via C—H⋯O interactions, forming a three-dimensional structure
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