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61.
A total of 73 soil samples were initially analyzed for lead (Pb) concentration as an indicator of the environment impact of smelter activity in the Port Pirie, South Australia. Chemometric techniques were used to assess the ability of near-infrared (NIR) reflectance spectroscopy to predict soil Pb using spectrally active soil characteristics such as soil carbon (C). The result indicated a strong linear relationship between log-transformed data of soil Pb and spectral reflectance in the range between 500 and 612 nm with R2 = 0.54 and a low root-mean-square error (RMSEv = 0.38) for the validation mode with an acceptable ratio of performance to deviation and ratio of error range (1.6 and 7.7, respectively). This study suggested that NIR spectroscopy based on auxiliary spectrally active components is a rapid and noninvasive assessment technique and has the ability to determine Pb contamination in urban soil to be useful in environmental health risk assessment.  相似文献   
62.
The aim of the present investigation was to determine the phytotoxic effect of aqueous extract from fresh and oven-dried leaves and roots of soybean plants on maize growth and on rhizosphere soil. The extract prepared from fresh leaves of drought-stressed soybean plants significantly increased the accumulation of proline, soluble sugar, and endogenous abscisic acid (ABA) content of maize-treated plants. Increase in antioxidant activity like superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), and endogenous ABA was recorded in treated plants. The soybean leaf extracts prepared from drought-stressed plants significantly decreased the soil pH and electrical conductivity (EC) of maize cultivated soil. The soybean drought-stressed leaf extracts prepared plants were found more effective in modulating the physiology of maize, indicating the higher allelopathic potential of soybean.  相似文献   
63.
For examining the probability of increase in the occupation ratio of inoculated rhizobium in nodules, various Rj-soybean cultivars including the Rj 2 Rj 3 Rj 4-lines of soybean were grown in a field of the Kyushu University Farm. Bradyrhizobium japonicum USDA110 that carries uptake hydrogenase (Hup+) was used as an inoculum. The relative efficiency of nitrogen fixation generally increased by the inoculation. However, there were no significant differences in the effects among the genotypes of the host plants. The occupation ratio of serogroup USDA110 in the nodules on the taproot of the inoculated plants was in the range of 77–100%, suggesting that the B. japonicum strain USDA110 infected taproots immediately after inoculation. The occupation ratios in the nodules on the lateral roots were 53–67, 40–86, 63–83, and 62–77% in inoculated plants of the non-Rj-, Rj 2 Rj 3-, Rj 4-, and Rj 2 Rj 3 Rj 4-genotypes, respectively, and they decreased in all the genotypes with the progression of growth. At the time of the first sampling, the occupation ratios on the lateral roots of these Rj 2 Rj 3 Rj 4-genotypes showed values intermediate between those of IAC-2 (Rj 2 Rj 3) and Hill (Rj 4) , which were the parent cultivars of the Rj 2 Rj 3 Rj 4-lines, B340, B349, and C242. The reduction in the occupation ratio of the serogroup USDA110 for about 1 month after the first sampling was the lowest (0.13–0.16) in the Rj 2 Rj 3 Rj 4-genotypes, excluding B349, followed by the non-Rj- and Rj 2 Rj 3-genotypes and highest (0.52–0.69) in the Rj 4-genotypes, excluding Hill. Therefore, it was considered that the population of compatible rhizobia with host soybean plants increased in the rhizosphere with the progression of the development and growth. The results showed that with the expansion of the root area of host plants, the occupation ratio of type A rhizobia including the serogroup USDA110 was high. Therefore, the Rj 2 Rj 3 Rj 4-genotypes were superior to other Rj-genotypes in terms of the inoculation effects of nodulation type A rhizobium, B. japonicum USDA110. However, the preference of the Rj 2 Rj 3 Rj 4-genotype for serogroup USDA110 is not sufficient to rule out the competition with the other serogroups in this study. Therefore, the study should be centered on the isolation of more efficient (Hup+) and highly compatible rhizobial strains with the Rj 2 Rj 3 Rj 4- genotypes.  相似文献   
64.
The nature of the pseudogap phase of cuprate high-temperature superconductors is a major unsolved problem in condensed matter physics. We studied the commencement of the pseudogap state at temperature T* using three different techniques (angle-resolved photoemission spectroscopy, polar Kerr effect, and time-resolved reflectivity) on the same optimally doped Bi2201 crystals. We observed the coincident, abrupt onset at T* of a particle-hole asymmetric antinodal gap in the electronic spectrum, a Kerr rotation in the reflected light polarization, and a change in the ultrafast relaxational dynamics, consistent with a phase transition. Upon further cooling, spectroscopic signatures of superconductivity begin to grow close to the superconducting transition temperature (T(c)), entangled in an energy-momentum-dependent manner with the preexisting pseudogap features, ushering in a ground state with coexisting orders.  相似文献   
65.
The current study was carried out at Agricultural College, University of Baghdad in the vegetable farm, Department of Horticulture during 2013 spring growing season. Yield response to irrigation of different crops is of major importance in production planning where water resources are limited. This study aims to determine the effect of different irrigation treatment (deficit irrigation) and potassium humate fertilizer on yield, content of nitrogen, potassium, and phosphor in tuber of potato and water use efficiency in the Abu-Graib Region, Iraq. Potato was grown under drip irrigation with three treatments: irrigation applied when evaporation 75%, 100% and 125% from pan A, and three potassium humate fertilizers: 0, 1.2 and 2.4 kg/ha with three times additions. The seasonal potato evapotranspiration ranged from 267 mm to 372 mm. The drip irrigation treatment had significant effecting tuber yield of potato recorder 29,530, 27,630 and 24,880 kg/ha for 125%, 100% and 75% from pan A evapotranspiration, respectively. Humus fertilizers addition has the lowest value of ETa 309 mm and maximum value of yield 2,930 kg/ha. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) values increased with increasing humus fertilizers, recording 9.92, 14.52, 8.59, 12.42 and 7.51, 10.70 kg/m3 for potassium humate K3 (2.4 kg/ha), K2 (1.2 kg/ha) and KI (0.0 kg/ha), respectively. Plants irrigated with 125% from class pans A evaporation, produced a significant increase in N, P and K content in tubers recorder 0.96%, 0.58% and 1.52%, respectively. Potassium humus-fertilizer significant differences among K1, K2 and K3 on high of plants reached 41.52, 50.08 and 56.39 cm, respectively, number of stems/plant 2.69, 3.22 and 3.78, respectively, leaves area index recorder 2.80, 3.35 and 3.73.  相似文献   
66.
A field study was conducted to investigate the influence of variable rates of application of N and P fertilizers in splits at various times on the growth and the seed and oil yields of canola (Brassica napus L.) during 1995–97. Rates of fertilizer application were 0 and 0 (F0), 60 and 0 (F1), 0 and 30 (F2), 60 and 30 (F3), 90 and 60 (F4) and 120 and 90 (F5) kg N ha?1 and kg P2O5 ha?1. All the P was applied at sowing while N was applied in splits, i.e. all at sowing, half at sowing and half with first irrigation, or half at sowing and half at flowering. The responses of growth, seed yield and components of yield were consistent in both years. Increasing the rate of fertilizer application from F4 (90/60 kg N/P2O5 ha?1) to F5 (120/90 kg N/P2O5 ha?1) increased the leaf area index (LAI) relative to the control and to lower rates of fertilizer application. For both crops, application of 90/60 kg N/P2O5 ha?1 significantly enhanced total dry matter (TDM) and seed yield. Seed yield increased mainly due to a greater number of pods per plant and seeds per seed‐pod. The time of fertilizer application did not significantly affect seed yield or components of yield in either season. Oil yield generally followed seed yield, increasing with increasing rate of fertilizer application up to 90/60 kg N/P2O5 ha?1. The maximum oil contents were obtained from the control. The results show that seed and oil yields of canola were maximized at the F4 (90/60 kg N/P2O5 ha?1) rate of application under the agro‐ecological conditions of Faisalabad, Pakistan.  相似文献   
67.
68.
Because of the relation between topology and function, there has been much interest in the structural transitions of the various conformations of DNA polymers. The x-ray fiber diffraction analysis system at the Daresbury Synchrotron Radiation Source was used to study the reversible transition between the B and D forms of the synthetic DNA poly[d(A-T)].poly[d(A-T)]. The gradual progression of conformations between these two forms indicates that the DNA double helix does not undergo a change of handedness during this transition.  相似文献   
69.
70.
A 3 × 3 factorial experiment was conducted on Labeo rohita fingerlings to evaluate the effect of dietary oxidized oil and vitamin E. Nine experimental diets were made, based on three degrees of oil oxidation (fresh oil, low oil oxidation and high oil oxidation), and each level of oxidation was further supplemented with three levels of vitamin E (0, 100 and 1,000 mg/kg). Weight gain% and specific growth rate (SGR) of fish fed fresh fish oil and low oil oxidation level were significantly higher than highly oxidized oil. Moreover, vitamin E supplemented fish also showed better growth performance. Oil oxidation caused a significant reduction in the concentrations of α‐tocopherol and increase in TBARS level and antioxidant enzyme activities in fish liver and muscles. However, increasing the dietary vitamin E abrogated these effects. Dietary vitamin E supplementation improved the fatty acid, more specifically polyunsaturated fatty acids profile of oxidized oil fed fish. In conclusion, dietary oxidized fish oil increased the oxidative stress condition of fish but supplementation of high dose of vitamin E prevented lipid oxidation, improved growth performance and fatty acid profile of L. rohita.  相似文献   
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