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1.
A field study was conducted to investigate the effects of three fertilizer placement methods and 11 fertilizer formulations on plant survival, economics of replanting, yield, and fruit size of two rabbiteye blueberry (Vaccinium ashei Reade) cultivars Tifblue and Woodard. Fertilizer rates were either mixed with the soil under plants (before planting), sidedressed, or half-rate was placed under plants with the other half sidedressed. Fertilizers at planting caused a total of 34% Woodard and 12% Tifblue plants to die as compared to 6% for Woodard and none for Tifblue when no fertilizer was applied. Fertilizer formulas 2-1-1 and 5-10-10 oxide ratios placed under Woodard plants caused 100% mortality whereas Tifblue fertilized with oxide ratios 2-2-2 and 5-10-10 under plants reached the maximum 50% mortality. Splitting fertilizer placement under the side of the plants resulted in less Woodard plant mortality (30%) than placing all the fertilizer under plants (54%). However, plant mortality for the side/under group was not different than sidedressing all fertilizer (23%). A planted hectare in this experiment consisted of 1852 Tifblue and 926 Woodard plants, providing one Woodard plant to pollinate two Tifblue plants. Based on the results obtained, the 5-10-10 fertilizer placed under plants would be expected to cause half the Tifblue (926 plants) and all the Woodard (926 plants) to be replanted. Plant costs alone was estimated to be $2315 with additional replanting costs of $93 for Tifblue and much higher for Woodard. Sidedressing 5-10-10 fertilizer eight weeks after planting would have prevented plant mortality. Placement of various fertilizers under Woodard or Tifblue plants resulted in a significant increase in plant mortality as compared to side placement of fertilizers. Yield loss due to plant mortality increased linearly with the N level of the fertilizers (ranging from 0 to 2) for both cultivars. Woodard fruit size was not affected by fertilizer placement but placing fertilizers under Tifblue plants produced smaller yields with larger fruit than sidedressed plants. Blueberry plants in a virgin acidic soil may experience no reduction in yield if fertilization is completely eliminated.  相似文献   

2.
Reversible potentials (E R) have been measured for nickel hydroxide/oxyhydroxide couples over a range of KOH concentrations from 0·01–10 M. It is shown that the couples derived from the parent- and-Ni(OH)2 systems can be distinguished by the relative change in KOH level on oxidation and reduction. In the case of couples derived from the-class of materials a dependence of 0·470 moles of KOH per 2e change is found compared with 0·102 moles of KOH per 2e change for the-class of materials. Couples derived from the- and-Ni(OH)2 systems can be encountered in a series of activated and de-activated forms having a range of formal potentialsE 0 . Activated. and de-activated-Ni(OH)2/-NiOOH couples are found to lie in the range 0·443–0·470 V whilst-Ni(OH)2/-NiOOH couples lie in the range 0·392–0·440 V w.r.t. Hg/HgO/KOH. It is demonstrated for de-activated,-Ni(OH)2/-NiOOH couples thatE R is independent of the degree of oxidation of the nickel cation between states of charge of 25% and 70%. SimilarlyE R is constant for states of charge between 12% and 60% for activated-Ni(OH)2/-NiOOH couples. The constant potential regions are considered to be derived from heterogeneous equilibria between pairs of co-existing phases both containing nickel in upper and lower states of oxidation. Differences inE 0 between the activated and de-activated couples are considered to be related to the degree of order/disorder in the crystal lattice.  相似文献   

3.
Summary Critical values of the polymer volume fraction 2,c and the interaction parameter c have been computed for the case that the equation for the chemical potential of solvent contains terms c 2 3 and c 2 4 in addition to 2 2 . For 0 c 1/3, the limits for infinite chain length are 2,c = 0 and c = 0.5. Quite different results are obtained for c > 1/3, 2,c being finite and c lower than 1/2. Conclusions for the estimation of the temperature and the entropy-of-dilution parameter are discussed.  相似文献   

4.
Summary Solid-state high-resolution 13C and 15N NMR spectra of microbial poly(-lysine) (-PL) derivatives with azo dyes have been measured. Chemically modified derivatives of -PL, -PL/MO and -PL/DC were prepared through reactions with methyl orange (MO) and dabsyl chloride (DC), respectively. Side chain -amino groups of -PL in -PL/MO are involved in ionic bonds with methyl orange to form poly-ion complexes, (-PL)-NH3+SO3--(MO). On the other hand, -PL is allowed to react with dabsyl chloride in -PL/DC to form covalent sulfonamide bonds, (-PL)-NH-SO2-(DC). These chemically modified -PLs exhibit 15N NMR signals characteristic of the binding mode at the -amino groups. The spectral analysis reveals that the -PL/DC sample contains a small amount of ion complexes with MO. It has been shown that 15N solid-state NMR is a useful tool for structural determination of -PL and its derivatives.  相似文献   

5.
Polymers of structure (SiR2SiR2-C C-SiR2SiR2-C C) n , in which ethynylene units alternate with disilylene units, have been prepared by two routes: (a) condensation of dichlorodisilanes with dilithium derivatives of 1,2-diethynyldisilanes and (b) ring-opening polymerization of strained cyclic disilanylene-acetylnes, (SiR2SiR2C C)2. The polymers display UV absorption near 240 nm indicative of – conjugation between the Si2 and the C C moieties. Polymers with R=R=n-Bu or R=n-Bu, R=Ph, undergo solid-state transitions to form liquid crystalline mesophases resembling those observed for many poly(silylenes). Single crystals were obtained for the polymer with R=R=CH3, by precipitation from dilute cyclohexane solution. The solid-state properties and structures of this family of polymers are discussed.This paper was presented at the Second International Topical Workshop, Advances in Silicon-Based Polymer Science.  相似文献   

6.
The electrodeposition of -nickel hydroxide is promoted by the simultaneous chemical corrosion of the electrode by an acidic nitrate bath. Chemical corrosion results in the formation of a poorly ordered layered phase which is structurally similar to -nickel hydroxide and provides nucleation sites for the deposition of the latter. Therefore under conditions which enhance corrosion rates such as low current density (<1.3 mA cm–2), high temperature (60 C), high nickel nitrate concentration ( 1M) and the resultant low pH (1.7), -nickel hydroxide electrodeposition is observed, while -nickel hydroxide forms under other conditions. Further, -nickel hydroxide deposition is more facile on an iron electrode compared to nickel or platinum.  相似文献   

7.
Summary -form isotactic polypropylene shows -recrystallization behavior (recrystallization from - to -form) during slow heating. This is enhanced by deformation. -form specimen with uniaxially oriented lamellae was deformed by rolling, and -recrystallization was studied by DSC and x-ray diffraction. The result showed that (1) — recrystallization is promoted with the degree of deformation. (2) Deformed specimen shows -recrystallization from considerably low temperature compared with the undeformed one. (3) The recrystallized -form is c-axis-oriented along the roll direction. From these results the -recrystallization mechanism was discussed in view of -nucleus formation by deformation.  相似文献   

8.
According to previous Mössbauer data [1] -sites formation at the activation of Fe-containing zeolites is accompanied by irreversible self-reduction of the iron, proceeding without participation of an external reducing agent. Reduced Fe2+ ions are inert to O2 but are reversibly oxidized to Fe3+ by N2O, generating the -oxygen species, O, which provide selective oxidation of hydrocarbons.In this work, the mechanism of -sites formation was studied via quantitative measurement of the dioxygen amount desorbed into the gas phase at the step of self-reduction. A prominent role of the zeolite matrix chemical composition has been revealed. For example, with zeolites of Al–Si composition (FeZSM-5 and Fe-), heating to 900 °C in a closed vacuum space leads to irreversible evolution of O2, which is accompanied by the immediate formation of -sites. Similar heating of B–Si and Ti–Si zeolites also leads to dioxygen evolution; however, this evolution is reversible and is not accompanied by formation of -sites. Activation of these zeolites occurs only in the presence of water vapor. Stoichiometric measurements showed that in terms of charge one regular O2- ion, removed at the activation, is equivalent to two -oxygen atoms. So, -oxygen is identified as an ion-radical species O -., whose unique oxidation properties still distinguish it from the generally observed O-. radicals.The mechanism of -sites formation is proposed, in which the process of strong chemical stabilization of reduced Fe2+ atoms in the zeolite structure is a key step, making impossible the reoxidation of the iron with O2.  相似文献   

9.
As a result of detailed polarization, volumetric and optical,in situ investigations of the growth rate of hydrogen bubbles during the electrowinning of zinc from Ni2+-containing sulphate electrolytes and in the presence of an inhibitor, a relationship has been established between the shape of the hydrogen bubbles and the duration of the induction period. It has been found that during the induction period hydrogen bubbles alter their shape from spherical at the beginning to cupola-shaped at the end, thus increasing by 10–12 times the extent of the screening of the cathode surface beneath. Experimental confirmation is presented for the validity of the previously proposed [1] physical model for the nature of the induction period.  相似文献   

10.
Summary Molecular motions of elastomers under deformations were observed through dynamic mechanical measurements. Composite master curves of dynamic moduli E and E and loss tangent tan over a wide range of frequency and in a state of elongation were obtained by the time-temperature superposition procedure. It is found that both moduli increase with strain, . The slope of the dispersion curve of E become more gradual with the increase in , while that of E is almost unchanged. The increment of E is generally larger than that of E, which does not agree with the N. W. Tschoegl prediction, E * ()=f() E o * (), where E * () and E o * () are complex moduli at the strain of and O, respectively, and f() is the function of only . The difference in the strain dependence of E from E was found to correspond to the strain dependence of the equilibrium modulus.  相似文献   

11.
The effectiveness of coastal superphosphate and two rock phosphate fertilizers was compared with the effectiveness of single superphosphate for pasture production on deep, humic, sandy podzols in high rainfall (> 800 mm annual average) areas of south-western Australia. The pastures were subterranean clover (Trifolium subterraneum) or mixed subterraneum clover and serradella (Ornithopus compressus). Coastal superphosphate was made by adding rock phosphate and elemental sulphur to superphosphate during manufacture, as it came out of the den before granulation. One rock phosphate was a 50% mixture of apatite rock phosphate from Nauru and Christmas Islands, and which was also used to make the single and coastal superphosphate used in this study, and superphosphate made in Western Australia at the time these experiments started. The other rock phosphate was Calciphos, the fertilizer produced by heating (calcining), at about 500 °C, Christmas Island C-grade ore, a calcium iron aluminium rock phosphate. There were two types of experiments. In the three Type 1 experiments, levels of each fertilizer were applied annually. In the two Type 2 experiments, levels of fertilizer were applied once only to new plots in different years. Coastal superphosphate was the most effective fertilizer in the Type 1 experiments, with both rock phosphates and single superphosphate being equally effective. All fertilizers were equally effective in the Type 2 experiments. There were large variations in fertiliser effectiveness values between yield measurements in the same or different years. It is known that P leaches from freshly-applied superphosphate in these soils. The extent of this leaching probably varies between yield measurements affecting effectiveness values determined for all fertilizers because the effectiveness values were calculated relative to the effectiveness of single superphosphate. The humic, sandy podzols remain wet during the growing season, are acidic, and are known from laboratory studies to possess adequate hydrogen ions to cause extensive dissolution of North Carolina rock phosphate so that rock phosphates are equally or more effective than single superphosphate in these soils. When elemental sulphur in coastal superphosphate is oxidized to SO4 hydrogen ions are produced which in previous studies has been shown to enhance dissolution of rock phosphate in biosuper, a mixture of rock phosphate and elemental sulphur.  相似文献   

12.
The oxidative methylation of -, - and -picolines with methane to the corresponding vinyl- and ethylpyridines was carried out at 750°C and under normal atmospheric pressure, over sodium, cesium or sodium-cesium promoted magnesia catalysts. Among the three picolines, the -picoline was the most reactive, followed by - and -picolines. The (5 mol% Na-5 mol% Cs)/MgO catalyst provided higher yields than the individual promoters, at the same total alkali content of 10 mol%.  相似文献   

13.
Summary Ruthenium catalyzed step growth copolymerization of 4-acetylbenzo-15-crown-5 and 4-acetylbenzo-18-crown-6 and ,-dienes such as 1,3-divinyltetramethyldisiloxane or 3,3,6,6-tetramethyl-3,6-disila-1,7-octadiene give novel copolymers which incorporate crown ethers into the polymer backbone in a regular manner. The synthesis of these thermally stable copolymers and their characterization is reported. Lithium cation crown complexes have been formed.  相似文献   

14.
Strontium ferrates and cobaltates with compositions SrFeO3- (0.060.40) and SrCoO3- (0.040.30) were synthesized. The dependence of the oxygen electrode properties on the value was examined in 1 mol dm–3 KOH solution. In the SrFeO3- series, the samples with 0.24<<0.29, showed the highest activity in both oxygen evolution and reduction reactions. In contrast, no strong dependence on the value was observed in SrCoO3-, which also showed a high catalytic activity for oxygen evolution.  相似文献   

15.
The textural and structural modifications involved in electrochemical redox cycling of turbostratic nickel (II) hydroxide has been investigated using X-ray diffraction and electron microscopy methods. It was found that during the first cycles, different phenomena compete: redox reactions which occur in the solid state, and ageing reactions via the solution. For the first galvanostatic charge performed at the C/5 rate in 4.5 N KOH, the direct oxidation of (II) to (III) and the ageing of (II) to (II) via the solution followed by the oxidation to (III) are in competition. The study of the discharge mechanism shows that the direct reduction (III)(II) is parallel to the reduction (III)(II) and the ageing of the turbostratic hydroxide via the solution. After the first cycle it was established that the alpha-generated (II) active phase consisted of a mixture of two kinds of particles, the oxidation of which follows two paths: (II)/(III) for the thicker particles and for the thinner (II)/(III), but these latter (II) particles aged via the solution by Oswald ripening and the (II)/(III) couples swung to (II)/(III).  相似文献   

16.
Summary The various methods of synthesis which can be used to prepare -carboxy polyoxyethylenes are reviewed. The synthesis and the purification of -methoxy -carboxy polyoxyethylenes ( ) are reported. The process consists of the reaction of halogenoacetic acids with an -methoxy -sodium hydroxylate polyoxyethylene followed by a purification by extraction. ,-dimethoxy and -methoxy -ethyl carboxylate polyoxyethylenes were synthesized.  相似文献   

17.
Two sex pheromone components, 3(Z),6(Z),9(Z)-nonadecatriene (3Z,6Z,9Z-19 H), and 3(Z),6(Z),9(Z)-eicosatriene (3Z,6Z,9Z-20 H), have been positively identified, and a third component, 6(Z),9(Z)-nonadecadiene (6(Z),9(Z)-19 H) has been tentatively identified from abdominal tip extracts of female spring cankerworm moths,Paleacrita vernata Peck (Lepidoptera Geometridae). The pheromone components were identified by a combination of gas chromatography, electroantennography, mass spectrometry, chemical tests, comparison with standards, and field testing. Only 3Z,6Z,9Z-20 H exhibited significant attractant activity when tested alone, and it was potentiated by the other two components. The attractive blend was an 821 ratio of 3Z,6Z,9Z-20H/3Z,6Z,9Z-19H/6Z,9Z-19H. However, the two-component blend of 3Z,6Z,9Z-20 H and 6Z,9Z-19 H (81 ratio) was as attractive as the three-component blend in further field tests. A series of related compounds, the diene monoepoxides available from epoxidation of C19 and C20 3Z,6Z,9Z-trienes, some of which have been found in the pheromone blends of other moth species, were tested as behavioral antagonists. The attraction of male moths to synthetic lures was suppressed by the addition of 6Z,9Z-cis-3,4-epoxy-nonadecadiene to the lures. Additional experiments were performed to determine the effects of lure dosage, trap height, and trap design on the numbers of male moths captured.Issued as NRCC 30711.  相似文献   

18.
The qualitative and quantitative composition of the principal lipid constituents of Siberian musk deer (Moschus moschiferus) preputial gland secretion, main odor carriers and potential precursors of odorous substances, was investigated by means of high-performance liquid chromatography. Free fatty acids and phenols (10%), waxes (38%), and steroids (38%) were found to be the main groups of the secretion lipids. Cholestanol (I), cholesterol (II), androsterone (III), 4-3-hydroxy-17-ketoandrostene (IV), 5, 3-hydroxy-17-ketoandrostane (V), 5, 3, 17-dihydroxyandrostane (VI), 5, 3, 17-dihydroxyandrostane (VII), and 5, 3, 17-dihydroxyandrostane (VIII) were isolated from the steroid fraction and their structures confirmed by IR, PMR, and mass spectra. 3-Methylpentadecanone (muscone) was not identified among the secretion lipids. Preputial gland secretion stimulated sex behavior of musk deer females.  相似文献   

19.
The electrochemical behavior of non-alkyl substituted viologen, 4,4-dibenzyl bipyridinium (BzV), 4,4-dicyanophenyl bipyridinium (CyV) and -,-,-cyclodextrin (, , -CD) was studied using cyclic voltammetry and a spectroelectrochemical method. It was found that BzV and Fe(CN) 6 4– formed a charge-transfer (CT) complex with a ratio of 21 and the colour of the solution faded with the addition of an electrolyte. This behaviour is the same as in then-heptyl viologen and ferrocyanide system [1]. BzV, -CD and -CD formed an inclusion complex only in the reduced state, whilst BzV and -CD formed an inclusion complex in both the oxidized and the reduced state. An EC scheme in which a chemical reaction follows an electrochemical reaction was considered to predominate in the BzV and -, -CD systems, while a CE scheme in which a chemical reaction preceded an electrochemical reaction predominated in the BzV and -CD system. On the other hand, CyV was found to form an inclusion complex with -, -, -CD in both the oxidized and the reduced states. therefore a CE scheme was considered to predominate in the CyV--, -, -CD systems.  相似文献   

20.
Summary By means of a new tensile rheometer for polymer melts, stress-strain curves () and the elastic recovery R() of a low density polyethylene melt were measured up to total strains =7, i.e. stretch =1097, at 150°C and two strain rates, =0.03 and 0.1 s–1. Tensile tests up to very high strains e give relevant results only if the test performance is characterized by quality parameters which are defined and given in this paper. The test results show a maximum in a as well as in R at about =5.5. Hence, in the range of investigated, a rheologically steady-state of flow does not exist.  相似文献   

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