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991.
Ali Osman Abdel-Rahaman M. Merwad Azza H. Mohamed Mahmoud Sitohy 《Molecules (Basel, Switzerland)》2021,26(9)
Papain and pepsin-hydrolyzed whey protein (PAH and PEH, respectively) were prepared and characterized for its degree of hydrolysis, chemical constituents (amino acid and peptides) and antioxidant activity. A field experiment was conducted at El Salheya El Gedida City, Sharqia, Egypt, during the seasons 2019 and 2020, to investigate the biological action of the foliar spray of PAH and PEH on the growth and yield of pea plants cultivated in a clay loam soil. Foliar application of the papain and pepsin-hydrolyzed whey protein (PAH and PEH, respectively) at 1000 and 2000 mg/L was applied three times after 25, 35 and 45 days from planting. All protein foliar spray treatments had significant positive effects on the uptake of N, P and K, simultaneously increasing the contents of all the photosynthetic pigments (Chlorophyll a, Chlorophyll b and Carotenoids) in a concentration-dependent manner. The most conspicuous increase was seen in Chlorophyll b (105% increase), followed by Carotenoids (91% increase). Generally, the favorable increases caused by the second level of application (2000 mg/L) were nearly 2–3 times that of the low level (1000 mg/L). Pod growth and formation indicators, e.g., no. of pod/plant, pod length and no. of seeds/pod, responded more evidently to the hydrolyzed than the intact form of whey protein treatments. Hydrolyzed whey protein foliar spray treatments achieved significantly higher increases in the global field yield components of Pisum sativum plants than the intact form, where peptic hydrolysates were significantly superior to papain hydrolysate. The treatment PEH (2000 mg/L) can be recommended as the most effective bio-stimulating foliar spray treatment for higher plant productivity when applied 25, 35 and 45 days after planting. 相似文献
992.
In this work, the activity concentrations (radioactivity) and distributions of natural radionuclides in peat moss samples were investigated. The measurements were performed using HP-Ge detector and XRD technique. The samples represent six types of soils. The concentrations of radionuclides of 238U, 226Ra, 232Th and 40K are ranged from 17.14 to 130.83, 13.19 to 26.09, 5.33 to 25.2 and 143.26 to 600.31 Bq · kg–1 (dry weight), respectively, for the different samples. This work also highlights that no correlation has been observed between radionuclides present in the samples, which in turn reflects the random method behind the preparation of the samples. The obtained results from the XRD analysis were in good agreement with radiometry measurements. The safety of peat moss uses was limited for certain agricultural crops due to the presence of high percent of sulphur in some types of soil. The radon concentration calculated using the empirical formula is more accurate than those obtained from the manual measurements and significant values were expected to emanate from the samples under investigation. 相似文献
993.
The gradient theory of elasticity with damping is successfully employed to explain the experimentally observed shift in resonance frequencies during forced harmonic torsional vibration tests of columns made of fine-grained material from their theoretically computed values on the basis of the classical theory of elasticity with damping. To this end, the governing equation of torsional vibrations of a column with circular cross-section is derived both by the lattice theory and the continuum gradient elasticity theory with damping, with consideration of micro-stiffness and micro-inertia effects. Both cases of a column with two rotating masses attached at its top and bottom, and of a column fixed at its base carrying a rotating mass at its free top, are considered. The presence of both micro-stiffness and micro-inertia effects helps to explain the observed natural frequency shift to the left or to the right of the classical values depending on the nature of interparticle forces (repulsive or attractive) due to particle charge. A method for using resonance column tests to determine not only the shear modulus but also the micro-stiffness and micro-inertia coefficients of gradient elasticity for fine-grained materials is proposed. 相似文献
994.
Preliminary results on the emission sources of atmospheric phosphine and the types of its precursors in the environment are described. Sunlight plays a more important role than oxygen in its degradation. The vertical profile of phosphine levels in ambient air has been measured. Laboratory simulation of phosphine formation under anaerobic conditions shows that addition of chicken manure, bone powder, or lecithin leads to an increment in phosphine emission. Phosphine can also be adsorbed to soil matrix and thus can survive in soil and sediment. Adsorption and light degradation explain the low ambient levels of phosphine. 相似文献
995.
采用一种新的X射线荧光UNIQUANT软件分析方法,分析了土壤标准物质和未知样品,土壤标准物质的分析结果与标准值较吻合,除氧化钠和氧化镁的相对偏差较高外,其余氧化物的相对偏差在0~10%之间。 相似文献
996.
Summary A novel method for the extraction into an aqueous medium of PAHs in soil is described, where sodium dodecyl sulphate (SDS)
is used as micelle former. After optimisation of this step using a multivariate approach, recoveries of the target analytes
from spiked soil ranging between 98.3%–99.7% were obtained when the samples were subjected to extraction with 25 mL of an
aqueous SDS solution (2.9 10−2 mol L−1) while irradiated with focused microwaves at 240 W for 40 min. The overall method involving determination of the extracted
compounds consists of three steps: 1) extraction of the analytes into the aqueous micellar medium assisted by focused microwaves;
2) trapping of the analytes on a C18 cartridge for clean up and preconcentration and; 3) HPLC separation with fluorimetric detection. The method was validated
using the certified reference material CRM 524 and the results found were in agreement with the certified values. 相似文献
997.
Summary A method for determination of trace amounts of the pesticides tebufenpyrad and oxadiazon, previous solid-phase microextraction
(SPME), was developed using gas chromatographymass spectrometry and selected ion monitoring (GC-MS; SIM). Both pesticides
were extracted with a fused silica fiber coated with 100 μm polydimethylsiloxane. The effects of pH ionic strength, sample
volume, extraction and desorption times as well as extraction temperature were studied. The linear concentration range of
application was 0.5–250 ng mL−1 for both compounds, with a detection limit of 0.06 ng mL−1 for tebufenpyrad and 0.02 ng mL−1 for oxadiazon. SPME-GC-MS analysis yielded good reproducibility (RSD between 7.5–10.1%). It was used to check the eventual
existence of tebufenpyrad and oxadiazon above this limit in water and soil samples from Granada (Spain) as well as in human
urine samples. The method validation was completed with spiked matrix samples. It can be applied as a monitoring tool for
water, soil and urine in the investigation of environmental and occupational exposure to tebufenpyrad and oxadiazon. 相似文献
998.
粗径毛细管气相色谱法测定F8426在土壤和小麦中的残留量 总被引:2,自引:0,他引:2
用气相色谱法测定了快灭灵 40 %干悬浮剂中F842 6在土壤和小麦中的残留量。用丙酮 水 (体积比为 80∶2 0 )溶液提取土壤和小麦样本中的F842 6 ,然后用石油醚萃取。石油醚相经浓缩后过弗罗里硅土和活性炭 (0 97g +0 0 3g)混合小柱净化 ,再用OV 170 1粗径毛细管柱分离 ,用电子捕获检测器 (ECD)测定。该方法对F842 6的最小检出量为 0 0 2ng ,在小麦和土壤中F842 6的最低检出限分别为 2 μg/kg和 1μg/kg ,对土壤和小麦空白样本的平均添加回收率为 89 6 0 %~ 97 5 3%,变异系数为 4 42 %~ 8 6 7%。。 相似文献
999.
水稻缺锌与环境关系的研究 总被引:4,自引:0,他引:4
综述了土壤中的锌含量及其分布规律,水稻缺锌发生的情况以及导致水稻缺锌的因素,表明水稻缺锌受多种因素影响。 相似文献
1000.