排序方式: 共有35条查询结果,搜索用时 31 毫秒
21.
Park Hyun-Jung Park Hyun-Jin Yang Hye In Park Se-In Lim Sang-Sun Kwak Jin-Hyeob Lee Goon-Taek Lee Sang-Mo Park Man Choi Woo-Jung 《Journal of Soils and Sediments》2019,19(1):310-321
Journal of Soils and Sediments - Lead (Pb) sorption capacity (PbSmax) and distribution in chemical and particle-size fractions of six soils with different physico-chemical properties were... 相似文献
22.
Sang-Sun Lim Hye In Yang Hyun-Jin Park Se-In Park Bo-Seong Seo Kwang-Seung Lee 《Soil Science and Plant Nutrition》2020,66(1):60-75
ABSTRACT The properties of secondary salt-affected soils developed from improper irrigation and drainage management and their effects on rice growth and yield are well documented. However, relevant information on coastal reclaimed tideland (RTL) soils, which are classified as primary salt-affected soils developed through salt-accumulated sediments is lacking. In this paper, we reviewed the physical and chemical properties of RTL soils in comparison with non-RTL soils and analyzed the relationship between rice production and soil salinity in RTL to suggest agricultural management practices for sustainable rice production and soil carbon sequestration in RTL. Similar to the secondary salt-affected soils, RTL soils were characterized by high alkalinity, salinity, and sodicity, and rice yield was negatively correlated with salinity. However, it was also found that lower fertility (e.g., organic matter and phosphorus) of RTL soils than non-RTL soils might also hamper rice growth and thus carbon input via plant residues in RTL soils. Correlation between years after reclamation and soil properties of RTL showed that cultivation of rice with annual fertilization and organic matter inputs increased soil fertility but salinity and sodicity did not show a significant tendency of change, suggesting that natural desalinization in RTL soils is hard to be achieved with conventional rice cultivation. Therefore, it is suggested that fertilization management as well as salinity management via drainage, gypsum application, tillage, and proper irrigation may be necessary to improve rice production and carbon sequestration in RTL soils. 相似文献
23.
Kim HJ Fonseca JM Choi JH Kubota C 《Journal of agricultural and food chemistry》2007,55(25):10366-10372
The effect of exogenous methyl jasmonate (MeJA) on antioxidative compounds of romaine lettuce ( Lactuca sativa L.) was investigated. Lettuces were treated with various MeJA solutions (0, 0.05, 0.1, 0.25, and 0.5 mM) before harvest. Total phenolic compounds content and antioxidant capacity of romaine lettuce significantly increased after MeJA treatments (0.1, 0.25, and 0.5 mM). The total content of phenolic compounds of the romaine lettuce treated with 0.5 mM MeJA (31.6 microg of gallic acid equivalents/mg of dry weight) was 35% higher than that of the control. The increase in phenolic compound content was attributed to a caffeic acid derivative and an unknown phenolic compound, which also contributed to increased antioxidant capacity. The induction of phenylalanine ammonia-lyase (PAL) activity by the MeJA treatment indicated that phenolic compounds were altered due to the activation of the phenylpropandoid pathway. Total content of carotenoids, including lutein and beta-carotene, of the MeJA-treated lettuce did not change after 8 days of treatment, whereas the content of the control without MeJA decreased after 8 days. This research indicated that preharvest application of MeJA could increase the nutritional value of romaine lettuce under determined conditions discussed in this work. 相似文献
24.
25.
Kim HJ Chen F Wang X Chung HY Jin Z 《Journal of agricultural and food chemistry》2005,53(20):7691-7695
Antioxidant capacities of vetiver (Vetiveria zizanioides) oil were evaluated by two different in vitro assays: the DPPH* free radical scavenging assay and the Fe2+-metal chelating assay. Results showed that the vetiver oil (VO) possessed a strong free radical scavenging activity when compared to standard antioxidants such as butylated hydroxytoluene (BHT) and alpha-tocopherol. However, its metal chelating capacity was relatively weak. VO (10 microL/mL) dissolved in methanol exhibited approximately 93% free radical scavenging activity in the DPPH* assay and approximately 34% Fe2+ chelating activity in the metal chelating assay. By contrast, 10 mM BHT and 0.1 mM alpha-tocopherol exhibited 93 and 89% free radical scavenging activities in the DPPH* assay, respectively, and 1 mM EDTA exhibited approximately 97% activity in the metal chelating assay. Among the complex constituents in the crude VO, beta-vetivenene, beta-vetivone, and alpha-vetivone, which had shown strong antioxidant activities, were isolated and identified using various chromatographic techniques including silica gel open column chromatography, silica HPLC, and GC-MS. These results show that VO and some of its inherent components can be potential alternative natural antioxidants. 相似文献
26.
The HVI properties and Mantis® single fiber tensile properties were analyzed to evaluate the relationship between fiber and bundle tensile properties. For this study, a new method has been developed for estimating the modulus and toughness of cotton fiber bundles directly from the HVI tenacity-elongation curves. The single fiber tensile properties were shown to be translated well into the bundle tensile properties. The single fiber breaking elongation was found to be the most significant contributing factor to bundle tensile properties. The bundle breaking elongation and toughness were shown to increase as the single fiber breaking elongation increased. The bundle modulus increased as the single fiber breaking elongation and/or standard deviation of single fiber breaking elongation decreased. 相似文献
27.
Molecular affinity and permeability of different molecular weight chitosan membranes 总被引:3,自引:0,他引:3
Chen XG Zheng L Wang Z Lee CY Park HJ 《Journal of agricultural and food chemistry》2002,50(21):5915-5918
Membranes were prepared from chitosan with different molecular weights by a casting method. The molecular affinity and permeability of the membranes for sodium chloride, glucose, tyrosine, and bovine serum protein were measured at 4 degrees C and pH 7. The molecular permeability of the chitosan membranes was inversely related to molecular weight. All prepared membranes showed a molecular affinity to bovine serum protein. The higher the molecular weight of chitosan membrane, the higher the affinity and the lower permeability of the membrane to bovine serum protein. 相似文献
28.
We present a new approach to bale laydown grouping, which improves the laydown to laydown uniformities, compared to conventional
approaches. In this approach, we use a frequency-relative picking method based on an HVI quality index for cotton bale selection
and laydown formation. We demonstrate the effectiveness of this approach by computer simulation on real HVI data of 1500 cotton
bales. Simulation results show that the proposed method significantly outperforms random picking. 相似文献
29.
Ah-Young Kim Raheem Shahzad Sang-Mo Kang Chang-Woo Seo Yeon-Gyeong Park Hyun-Jin Park In-Jung Lee 《Journal of Crop Science and Biotechnology》2017,20(4):235-242
Soybean is known to be intolerant of waterlogged conditions. Flooding stress usually affects the crop via poor and retorted root development. The current study aimed to isolate indole acetic acid (IAA)-producing bacteria with potential to induce adventitious root growth and counteract flooding stress. The isolate AY-13 was identified as Klebsiella variicola using 16S DNA sequencing and phylogenetic analysis. A pure culture of AY-13 Klebsiella variicola was subjected to chromatography and mass spectrometry selected-ion monitoring (GC-MS/SIM) for IAA quantification. The results revealed the presence of (84.27±3.55 μg/mL) IAA in the AY-13 culture. The strain AY-13 was able to induce adventitious root initiation. Therefore, soybean seedlings were inoculated with AY-13 to examine its potential for promoting growth and reprograming after flooding stress. AY-13 application not only mitigated the flooding stress, but also significantly improved the plants’ growth, enhanced chlorophyll contents, and improved the quantum efficiency of chlorophyll fluorescence during and after flooding stress. Our findings were that AY-13 possesses great potential for mitigating flooding stress and improving soybean plant growth. 相似文献
30.
Kim HJ Chen F Wu C Wang X Chung HY Jin Z 《Journal of agricultural and food chemistry》2004,52(10):2849-2854
Antioxidant activity of Australian tea tree (Melaleuca alternifolia) oil (TTO) was determined using two different assays. In the 2,2-diphenyl-1-picrylhydrazyl assay, 10 microL/mL crude TTO in methanol had approximately 80% free radical scavenging activity, and in the hexanal/hexanoic acid assay, 200 microL/mL crude TTO exhibited 60% inhibitory activity against the oxidation of hexanal to hexanoic acid over 30 days. These results were equivalent to the antioxidant activities of 30 mM butylated hydroxytoluene in both tests at the same experimental conditions. This indicated that the TTO could be a good alternative antioxidant. Inherent antioxidants, i.e., alpha-terpinene, alpha-terpinolene, and gamma-terpinene, in the crude TTO were separated and identified chromatographically using silica gel open chromatography, C(18)-high-pressure liquid chromatography, and gas chromatography-mass spectrometry. Their antioxidant activities decreased in the following order in both assays: alpha-terpinene > alpha-terpinolene > gamma-terpinene. 相似文献