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1.
火焰原子吸收法测定苹果中波尔多液的农药残留 总被引:1,自引:0,他引:1
通过原子吸收法测定苹果果皮、果肉上波尔多液的农药残留铜的含量,结果表明:喷洒了波尔多液的苹果果皮上铜含量明显大于果肉,在果皮上有一定的农药残留;而未喷洒波尔多液的苹果果皮和果肉中铜的含量的差异很小。 相似文献
2.
Fengjiang is a large e-waste dismantling site located in southeast China. In this paper, apple snail and soil samples were collected from this e-waste dismantling site and 25 vicinal towns to investigate the contamination status, spatial distributions and congener patterns of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). Total PCB concentrations in apple snails (3.78-1812 ng g−1 dry weight (dw)) were significant higher than that in soil samples (0.48-90.1 ng g−1 dw). PBDE (excluding BDE 209) concentrations in apple snail and soil samples ranged from 0.09 to 27.7 ng g−1 dw and 0.06 to 31.2 ng g−1 dw, respectively. Concentrations of PCBs and PBDEs in snails and soils correlated negatively with the distance from Fengjiang. Both the concentrations and profiles of the pollutants were significantly correlated (p < 0.05) between the snail and soil samples, indicating the suitability of apple snail as a reliable bioindicator for PCBs and PBDEs contamination in this region. Relatively high concentrations of PCBs and PBDEs at locations far from e-waste dismantling sites implied that these pollutants have been transported to surrounding regions. 相似文献
3.
The effects of apple pomace,bentonite and calcium superphosphate on swine manure aerobic composting 总被引:2,自引:0,他引:2
Jishao Jiang Yimei Huang Xueling Liu Hua Huang 《Waste management (New York, N.Y.)》2014,34(9):1595-1602
The effects of additives such as apple pomace, bentonite and calcium superphosphate on swine manure composting were investigated in a self-built aerated static box (90 L) by assessing their influences on the transformation of nitrogen, carbon, phosphorous and compost maturity. The results showed that additives all prolonged the thermophilic stage in composting compared to control. Nitrogen losses amounted to 34–58% of the initial nitrogen, in which ammonia volatilization accounted for 0.3–4.6%. Calcium superphosphate was helpful in facilitating composting process as it significantly reduced the ammonia volatilization during thermophilic stage and increased the contents of total nitrogen and phosphorous in compost, but bentonite increased the ammonia volatilization and reduced the total nitrogen concentration. It suggested that calcium superphosphate is an effective additive for keeping nitrogen during swine manure composting. 相似文献
4.
Hora RR Ionescu-Hirsh A Simon T Delabie J Robert J Fresneau D Hefetz A 《Die Naturwissenschaften》2008,95(1):55-60
In the ectatommine ant Ectatomma tuberculatum, the visual appearance of queens changes after mating and ovarian development in that their cuticle turns from shiny to matte.
In this study, we have shown that this change seems to be caused by 15-fold accumulation of hydrocarbons, in particular heptacosane
that covers the multiple grooves present on the cuticular surface creating a wax coat in mated fully fertile queens. Analyses
of the scrapped wax revealed that it is composed largely of heptacosane. Peak-by-peak comparison of the cuticular hydrocarbon
(CHC) composition of mated, virgin with developed ovaries and virgin with nondeveloped ovaries revealed significant differences
between the queen groups. Although the total amount of the CHC of virgin queens with developed ovaries was not higher than
virgin queens that did not have developed ovaries, the composition showed a shift toward the mated queen. While it is possible
that the large accumulation of hydrocarbons may give extra physical and chemical protection to queens, we propose that the
switch in the relative abundance of heptacosane and nonacosane and perhaps of other components is indicative of being a mating
and fertility cue. This is the first report in social insects where external chemical changes are accompanied by changes in
visual appearance. 相似文献
5.
Heather N. Koopman 《Marine Biology》2007,151(1):277-291
To explore ecological, phylogenetic, and developmental factors affecting the structure of blubber in Odontocetes (toothed
whales), lipid composition of this specialized adipose tissue was determined in 260 specimens (30 species representing all
families except the river dolphins), most of which were collected between 1995 and 2005, from all over the world. In most
odontocetes, blubber contained primarily triacylglycerols; the blubber of beaked and sperm whales was dominated by wax esters
(WE), exhibiting ontogenetic patterns of deposition. WEs may represent an adaptation to deep diving for marine mammals that
do not rely on blubber for stored energy. Fatty acid (FA) composition was stratified through blubber depth, with higher concentrations
of dietary FA in the inner and endogenous FA in the outer layers of the blubber. Stratification can be considered a characteristic
feature of odontocetes, and is likely the result of differential metabolism through the blubber. Small body size appears to
constrain blubber lipid content to be high. Thermal habitat also represents an important selective pressure for blubber composition.
Species inhabiting colder waters exhibited both higher lipid content and increased FA stratification in blubber, compared
to species from warm/tropical habitats. The isolation of mobilization to inner blubber may permit metabolic enzymes to function
without limitation by lower temperatures. The variation in composition and distribution of blubber lipids in odontocetes suggests
that different species may have evolved slightly diverse arrays of secondary functions for this specialized tissue as adaptations
for specific ecological niches.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
6.
The reactivity of the herbicide cycloxydim (CD) toward singlet oxygen was studied in organic solution and on wax films to mimic the leaf surface. Experiments in solution were conducted in acetonitrile using phenalenone as a sensitizer. For the experiments in the solid state, phenalenone was included in paraffinic wax films and CD deposited at the film surface. By laser flash photolysis we observed that the triplet of phenalenone reacts with CD with a bimolecular rate constant of (9.6 ± 1)×106 M−1 s−1. However, scavenging experiments using β-carotene as a singlet oxygen quencher showed that the observed CD degradation in aerated acetonitrile involves singlet oxygen essentially. The bimolecular rate constant of reaction of CD with singlet oxygen was evaluated to (1.0 ± 0.2)×107 M−1 s−1. Phenalenone included in the wax films also significantly increased the rate of CD photodegradation, the involvement of singlet oxygen being very likely. The photoproducts formed via the singlet oxygen pathway resulted from the oxidation of the thiol group and/or the cyclohexene ring. This study should help to better understand the fate of CD after its spraying on crops. 相似文献
7.
Bartosz Piechowicz Izabela Woś Magdalena Podbielska 《Journal of environmental science and health. Part. B》2018,53(1):18-24
This investigation was undertaken to determine whether active ingredients (AIs) of currently recommended plant protection products (PPPs) could be transferred to beehives from apple and pear trees. A field trial was carried out with apple trees of Ligol and Idared variety, and pear trees of Conference variety. For pest and diseases control of fungal origin, recommended PPPs were applied. Samples of flowers from the above-mentioned varieties of fruit trees, of bees, brood and honey from beehives located in their direct neighborhood were collected regularly and analyzed for the presence of lambda-cyhalothrin (an insecticide) and cyprodinil, captan, fluopyram, kresoxim-methyl, penthiopyrad and trifloxystrobin (fungicides). In samples of flowers of Ligol variety, fluopyram residues (on average 0.621 µg single flower?1) were at the highest levels, whereas in samples of pear flowers of Conference variety, and in flowers of Idared variety, captan residues (on average, respectively, 0.705 and 165.7 µg single flower?1). In samples of bees and honey, residues of five AIs were detected, and in brood six AIs, whereby in each case captan residues prevailed, respectively, up to 585.2, 51.52 and 126.5 µg kg?1 bees and honey. In the honey, significantly larger residues of captan were found out than maximum residue level (MRL) for this AI – 103.04% MRL. In the case of any AI, the daily intake did not exceed 0.002% acceptable daily intake (ADI). 相似文献
8.
Juan Angel Botas Mónica Bravo José María Escola Pablo García 《Journal of Material Cycles and Waste Management》2006,8(2):122-125
The economic success of feedstock recycling procedures for plastic wastes is increasingly demanding the conversion of the
starting residue into more valuable chemicals. Thermal cracking of polyethylenes leads to the preparation of equimolar mixtures
of n-paraffins and 1-alkenes within the C2–C100 range. These 1-olefins can be catalytically upgraded by selective oxidation processes to more valuable products (e.g., ketones
and fatty acids) with different uses such as polar waxes, cetane improvers, varnishes, and printer inks. The results obtained
on oxidation in a modified Wacker system of a model 1-olefin (1-dodecene) as well as of a distillate cut (C10–C25) of the product from the thermal cracking of urban polyethylene waste are described. 相似文献
9.
Nina Kopčić Marija Vuković Domanovac Dajana Kučić Felicita Briški 《Waste management (New York, N.Y.)》2014,34(2):323-328
Efficient composting process requires set of adequate parameters among which physical–chemical properties of the composting substrate play the key-role. Combining different types of biodegradable solid waste it is possible to obtain a substrate eligible to microorganisms in the composting process. In this work the composting of apple and tobacco solid waste mixture (1:7, dry weight) was explored. The aim of the work was to investigate an efficiency of biodegradation of the given mixture and to characterize incurred raw compost. Composting was conducted in 24 L thermally insulated column reactor at airflow rate of 1.1 L min?1. During 22 days several parameters were closely monitored: temperature and mass of the substrate, volatile solids content, C/N ratio and pH-value of the mixture and oxygen consumption. The composting of the apple and tobacco waste resulted with high degradation of the volatile solids (53.1%). During the experiment 1.76 kg of oxygen was consumed and the C/N ratio of the product was 11.6. The obtained temperature curve was almost a “mirror image” of the oxygen concentration curve while the peak values of the temperature were occurred 9.5 h after the peak oxygen consumption. 相似文献
10.
测定空气中甲醇的毛细管气相色谱方法研究 总被引:3,自引:0,他引:3
使用HP—Wax毛细管柱进行水样分析,甲醇和乙醇分离效果好,该方法的精密度和准确度高,每0.2μL的最低检出限为0.7ng。此法利用了化学工作站,使得分析更简单、方便。 相似文献