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91.
本文提出了一种快速、高效提取净化蔬菜、水果中残留硫双威的前处理方法和用火焰光度检测的气相色谱法。该法的最低检出浓度为0.04mg·kg^-1,在蔬菜,水果中的平均加标回收率分别为93.0-106.7%和94.5-104.2%,变异系数分别为2.57-6.05%和2.74-5.83%。 相似文献
92.
Summary. Domestic apple (Malus pumila)- and hawthorn (Crataegus sp.)-infesting races of Rhagoletis pomonella, Walsh (Diptera: Tephritidae) provide an excellent model to examine the role that host plant specificity plays during sympatric
speciation (i.e., divergence in the absence of geographic isolation). Previous work has shown that these races differ in their propensities
to accept apple and hawthorn fruits in behavioral choice assays, and that this discrimination translates into "host fidelity"
in the field (i.e., apple flies tend to mate on and oviposit into apples and hawthorn flies on hawthorns). ?We present the results of a study
examining possible physiological factors contributing to host choice differences in R. pomonella. We tested whether apple and hawthorn flies differ in their electroantennogram (EAG) responses to biologically relevant volatile
compounds emitted from apples and hawthorns. Significant differences were found in the relative EAG responses of apple and
hawthorn flies to host fruit compounds at five of six paired study sites across the eastern United States. The geographic
pattern of EAG variation was complex, however, with local populations of apple and hawthorn flies tending to be more similar
to one another than to flies of the same race at distant sites. This pattern was largely due to EAG responses for several
compounds showing longitudinal or latitudinal clines, the latitudinal clines being similar to those observed for allozyme
loci in the host races. We also found evidence for sex-related differences, as males tended to have higher mean EAG responses
to compounds than females. Host-associated differences were therefore nested within geographic and sex-related differentiation
in R. pomonella.?Further behavioral studies are needed to distinguish whether the EAG differences are responsible for, as opposed to being
a consequence of, host-plant fidelity and adaptation. Crosses are also required to establish a genetic basis for the EAG responses,
although we did find significant correlations between EAG scores for several compounds and the allozymes NADH-Diaphorase-2
and Hydroxyacid dehydrogenase at one of the study sites. Questions therefore remain concerning the evolutionary significance
of the EAG response differences between apple and hawthorn fly races. Nevertheless, these differences raise the possibility
that antennal responses to fruit-related volatile compounds contribute to host plant discrimination in R. pomonella. Regardless, the EAG responses represent another set of traits, in addition to diapause/eclosion time phenotypes and allozyme
frequencies, differing between apple and hawthorn host races of R. pomonella.
Received 17 March 1998; accepted 21 September 1989. 相似文献
93.
盐生植物在盐渍土壤改良中的作用 总被引:61,自引:0,他引:61
盐生植物盐爪爪〔Kalidiumfoliatum (Pall.)Moq.〕、盐地碱蓬 (SuaedasalsaL .Pall)、中亚滨藜 (AtriplexcentralasiatieaIljin)、西伯利亚白刺 (NitrariasibiricaPall) ,在中国禹城地区〔φ(N) =36°5 5′,λ(E) =116°40′〕含盐量较高 (1%~ 1.3%)的试验田中分别种植 .出苗后定苗 ,株密度n =80m-2 ,小区面积为 4m2 ,每种植物 3个重复 .种植前分别测定土壤Na+ 含量 ,N、P、K含量 ,有机质含量 ,细菌和真菌数量 .萌发后 15d测定植株干重、植株Na+ 含量 .在花芽形成期收获 ,再测定植物干重和植株Na+ 含量 ,以及土壤Na+ 含量 ,N、P、K含量 ,有机质含量 ,细菌和真菌数量 .结果发现 ,盐渍土壤种植 4种盐生植物 1个季度后 ,土壤Na+ 含量显著降低 ,每季盐爪爪从土壤中吸收Na+ 量 934 5 .6kg/hm2 ,盐地碱蓬吸收Na+ 量 6 85 1.4kg/hm2 ,西伯利亚白刺吸收 6 0 19.2kg/hm2 ,中亚滨藜吸收 6 0 98.4kg/hm2 .土壤有机质 ,N、P、K以及细菌和真菌数量也有不同程度的增加 .这再次证明 ,盐生植物是一类良好的吸盐植物 .并对盐渍土壤种植盐生植物后Na+盐降低、土壤肥力和微生物数量增加的原因进行了讨论 .表 7参 13 相似文献
94.
95.
To better understand the interaction mechanisms of plant surfaces with polar organic compounds, sorption of 4-chlorophenol, 2,4- dichlorophenol, and 2,4,6-trichlorophenol by fruit cuticles (i.e., tomato, apple, and pepper), and potato tuber periderm were investigated. The roles of cuticular components (waxes, cutin, cutan and sugar) on sorption of chlorophenols are quantitatively compared. Cutin and waxes govern the sorption capacity of bulk apple cuticle by hydrophobic interactions. Potato periderm with highest sugar content exhibits the lowest sorption capability for the chlorophenols. With the increase of hydrophobicity (i.e., Kow ) of sorbate, the relative contribution of lipophilic components (wax, cutin and cutan) on total sorption increases, however, the ratios of Koc to Kow decreases due to increasing ionization degree of sorbates. 相似文献
96.
97.
98.
Abdi Christia Arima Diah Setiowati Keikhosro Karimi Muhammad Nur Cahyanto Claes Niklasson 《International Journal of Green Energy》2016,13(6):566-572
Oil palm empty fruit bunch (OPEFB) is a potential raw material for production of lignocellulosic bioethanol. The OPEFB was pretreated with 8% sodium hydroxide (NaOH) solution at 100°C for 10 to 90 min. Enzymatic digestion was carried out using cellulase and β-glucosidase at 45°C for 24 h. It was then inoculated with Mucor indicus spores suspension and fermented under anaerobic conditions at 37°C for 96 h. Sodium hydroxide pretreatment effectively removed 51–57% of lignin in the OPEFB and also its hemicellulose (40–84%). The highest glucan digestibility (0.75 g/g theoretical glucose) was achieved in 40-min NaOH pretreatment. Fermentation by M. indicus resulted in 68.4% of the theoretical ethanol yield, while glycerol (16.2–83.2 mg/g), succinic acid (0–0.4 mg/g), and acetic acid (0–0.9 mg/g) were its by-products. According to these results, 11.75 million tons of dry OPEFB in Indonesia can be converted into 1.5 billion liters of ethanol per year. 相似文献
99.
《Journal of environmental science and health. Part. B》2013,48(3):385-396
Abstract A field study was conducted on a Lowell silty loam soil of 2.7% organic matter at the Kentucky State University Research Farm, Franklin County, Kentucky. Eighteen universal soil loss equation (USLE) standard plots (22 × 3.7 m each) were established on a 10% slope. Three soil management practices were used: (i) class-A biosolids (sewage sludge), (ii) yard waste compost, each mixed with native soil at a rate of 50 ton acre?1 on a dry-weight basis, and (iii) a no-mulch (NM) treatment (rototilled bare soil), used for comparison purposes. Devrinol 50-DF “napropamide” [N,N-diethyl-2-(1-naphthyloxy) propionamide]was applied as a preemergent herbicide, incorporated into the soil surface, and the plots were planted with 60-day-old sweet bell pepper seedlings. Napropamide residues one hour following spraying averaged 0.8, 0.4, and 0.3 μ g g? 1 dry soil in sewage sludge, yard waste compost, and no-mulch treatments, respectively. Surface runoff water, runoff sediment, and napropamide residues in runoff were significantly reduced by the compost and biosolid treatments. Yard waste compost treatments increased water infiltration and napropamide residues in the vadose zone compared to sewage sludge and NM treatments. Total pepper yields from yard waste compost amended soils (9187 lbs acre?1) was significantly higher (P < 0.05) than yield from either the soil amended with class-A biosolids (6984 lbs acre?1) or the no-mulch soil (7162 lbs acre ?1). 相似文献
100.
Behavior of pyrimethanil,pyraclostrobin, boscalid,cypermethrin and chlorpyrifos residues on raspberry fruit and leaves of Laszka variety 总被引:1,自引:0,他引:1
Stanisław Sadło Ewa Szpyrka Michał Stawarczyk Bartosz Piechowicz 《Journal of environmental science and health. Part. B》2013,48(3):159-168
The purpose of the research conducted was to investigate and evaluate the behavior of pyrimethanil, pyraclostrobin, boscalid, cypermethrin and chlorpyrifos, the active ingredients of selected fungicides and insecticides, on ripe fruit and in fully developed leaves of raspberry of the Laszka variety. The field trial was carried out in the period of one month starting from the first fruit picking. The results obtained indicated that residue levels on the day of the first crop picking did not even approximate the corresponding EU-MRLs (http://ec.europa.eu/sanco_pesticides). Individual substances in raspberry fruits and leaves disappeared at a similar rate. As a result of chlorpyrifos application to the soil, its residue in fruits and leaves occurred for the whole period of fruit bearing, though in fruit they dropped successively. To produce raspberries with residues below or equal to 0.01 μg g?1, the application of pesticides should be stopped at least 2–3 weeks before the first crop picking, and on condition that an appropriate preparation (active in low doses) is applied to the last treatments. 相似文献