Volatilization and photodecomposition of Plictran miticide.     

G N Smith  F S Fischer  R J Axelson 《Journal of agricultural and food chemistry》1976,24(6):1225-1229

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Weed management and irrigation are key treatments in emerging black truffle (Tuber melanosporum) cultivation     

A. Olivera  C. R. Fischer  J. A. Bonet  J. Mart��nez de Arag��n  D. Oliach  C. Colinas 《New Forests》2011,42(2):227-239

Interest in conversion of marginal agricultural lands to small oak woodlands for the production of black truffles (Tuber melanosporum Vittad.) is increasing in the native black truffle areas of France, Spain and Italy as well as suitable or amended sites throughout the world due to high economic returns for gastronomically valuable truffles. Successful long-term management of a perennial plantation replacing an annual crop requires understanding the system in all phases of the life cycle, and in the case of truffles this involves understanding the interactive growth of the aboveground host and the belowground symbiotic ectomycorrhizal fungus whose fruitbody is the desired truffle. Here we focus on the pre-production phase, 4 years after establishing the truffle-oak plantation and prior to truffle production. We tested the influence of weed control, irrigation and fertilizer, each at 3 levels, on plant growth and ectomycorrhizal proliferation in three truffle-oaks plantations in northeast Spain. Results show that adequate weed control improves root and shoot dry weight while fertilizer and irrigation treatments did not influence plant growth. The low dose of irrigation (50% of the estimated water deficit for the site) and glyphosate weed control both increased total root tips/plant and T. melanosporum colonized tips (ectomycorrhizae) by approximately two-fold, compared to control treatments. Distribution of the ectomycorrhizae within the soil profile was significantly influenced by the low dose irrigation treatment, with increases observed in the 10?C20 cm and the 20?C30 cm deep layers compared to the control and high irrigation treatments. Four years after planting, T. melanosporum remained the dominant fungal symbiont, despite the presence of 14 other ectomycorrhizal morphotypes from these sites.  相似文献   

Phäophytin in subhydrischen Fließwassersedimenten     

W. R. Fischer 《植物养料与土壤学杂志》1974,137(1):49-60

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Deutscher Zentralausschuß für Chemie,H. Grünewald (Herausg.): Internationale Regeln für die chemische Nomenklatur und Terminologie. Deutsche Ausgabe. Abschnitte A und B. Verlag Chemie GmbH., Weinheim 1975. Loseblatt-Ordner,DM 58,—     

W. R. Fischer 《植物养料与土壤学杂志》1977,140(2):241-242

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Demuth,R. und F. Kober: Grundlagen der Komplexchemie. 2., vollständig neu bearbeitete Auflage. Otto Salle Verlag,Frankfurt am Main,und Verlag Sauerländer,Aarau (1992). 218 S., gebunden DM 80,-. ISBN 3-7935-5483-X     

W. R. Fischer 《植物养料与土壤学杂志》1994,157(2):152-152

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Die Interpretation von K/Ca-Austauschkurven mit Hilfe einer einfachen GAPON-Gleichung     

Walter R. Fischer 《植物养料与土壤学杂志》1990,153(2):93-95

The interpretation of K/Ca exchange isotherms by a simple GAPON equation K/Ca exchange isotherms of various soils can be described by a GAPON equation, where the coefficients being fitted to the measured values by iteration. The resulting values for the “labile potassium” are very similar to those of exchangeable K, whereas only 5–25% of the cec is involved in the short-term K/Ca exchange.  相似文献   

Axonal neuregulin-1 regulates myelin sheath thickness     

Michailov GV  Sereda MW  Brinkmann BG  Fischer TM  Haug B  Birchmeier C  Role L  Lai C  Schwab MH  Nave KA 《Science (New York, N.Y.)》2004,304(5671):700-703

In the nervous system of vertebrates, myelination is essential for rapid and accurate impulse conduction. Myelin thickness depends on axon fiber size. We use mutant and transgenic mouse lines to show that axonal Neuregulin-1 (Nrg1) signals information about axon size to Schwann cells. Reduced Nrg1 expression causes hypomyelination and reduced nerve conduction velocity. Neuronal overexpression of Nrg1 induces hypermyelination and demonstrates that Nrg1 type III is the responsible isoform. We suggest a model by which myelin-forming Schwann cells integrate axonal Nrg1 signals as a biochemical measure of axon size.  相似文献   

First solvation shell of the Cu(II) aqua ion: evidence for fivefold coordination     

Pasquarello A  Petri I  Salmon PS  Parisel O  Car R  Toth E  Powell DH  Fischer HE  Helm L  Merbach A 《Science (New York, N.Y.)》2001,291(5505):856-859

We determined the structure of the hydrated Cu(II) complex by both neutron diffraction and first-principles molecular dynamics. In contrast with the generally accepted picture, which assumes an octahedrally solvated Cu(II) ion, our experimental and theoretical results favor fivefold coordination. The simulation reveals that the solvated complex undergoes frequent transformations between square pyramidal and trigonal bipyramidal configurations. We argue that this picture is also consistent with experimental data obtained previously by visible near-infrared absorption, x-ray absorption near-edge structure, and nuclear magnetic resonance methods. The preference of the Cu(II) ion for fivefold instead of sixfold coordination, which occurs for other cations of comparable charge and size, results from a Jahn-Teller destabilization of the octahedral complex.  相似文献   

Compressibility of M3C60 Fullerene Superconductors: Relation Between Tc and Lattice Parameter     

Zhou O  Zhu Q  Fischer JE  Coustel N  Vaughan GB  Heiney PA  McCauley JP  Smith AB 《Science (New York, N.Y.)》1992,255(5046):833-835

X-ray diffraction and diamond anvil techniques were used to measure the isothermal compressibility of K(3)C(60) and Rb(3)C(60), the superconducting, binary alkali-metal intercalation compounds of solid buckminsterfullerene. These results, combined with the pressure dependence of the superconducting onset temperature T(c) measured by other groups, establish a universal first-order relation between T(c) and the lattice parameter a over a broad range, between 13.9 and 14.5 angstroms. A small secondorder intercalate-specific effect was observed that appears to rule out the participation of intercalate-fullerene optic modes in the pairing interaction.  相似文献   

Stomatal opening: role of potassium uptake by guard cells   总被引：16，自引：0，他引：16  

R A Fischer 《Science (New York, N.Y.)》1968,160(829):784-785

Stomata in isolated epidermal strips open in response to light plus air free of carbon dioxide when the strips are floated on potassium chloride solutions of low concentrations. This opening depends on the stimulation of active accumulation of potassium in quantities sufficient to account for the observed changes in solute potential of the guard cells.  相似文献