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排序方式: 共有327条查询结果,搜索用时 78 毫秒
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Ratnamma Pasar Pallavi MS Harischandra Naik R Devaraj M Nandini P Bheemanna M Badariprasad P R Paramasivam M 《Journal of separation science》2022,45(11):1831-1838
This study presents the method development, validation, and simultaneous determination of dimethoate and its metabolite omethoate in curry leaf. Samples were extracted following modified quick, easy, cheap, effective, rugged, and safe extraction protocol and analyzed using liquid chromatography-tandem mass spectrometry. The limit of quantification in the matrix was 0.005 μg g−1 for dimethoate and omethoate. Extraction using acetonitrile recorded the average recoveries in the range of 82.25 to 112.97% for dimethoate and 85.57 to 107.22% for omethoate at 0.005, 0.025 and 0.050 μg g−1 fortification levels and relative standard deviation less than 5%. Similarly, the relative standard deviation values for intraday (Repeatability) and interday (Reproducibility) tests were less than 15%. Dissipation kinetics of dimethoate 30% emulsifiable concentrate at 200 and 400 g a.i h−1 recorded initial deposits of 5.20 and 10.05 μg g−1 and 0.33 and 0.48 μg g−1 for dimethoate and omethoate, respectively, and half-life of 3.07 and 3.34 days. The estimated hazard index value found more than one at a day after dimethoate application. It is not safe for consumer health to use curry leaves in the initial days after application. 相似文献
86.
Thompson H Soper AK Buchanan P Aldiwan N Creek JL Koh CA 《The Journal of chemical physics》2006,124(16):164508
Neutron diffraction studies with hydrogen/deuterium isotope substitution measurements are performed to investigate the water structure at the early, medium, and late periods of methane clathrate hydrate formation and decomposition. These measurements are coupled with simultaneous gas consumption measurements to track the formation of methane hydrate from a gas/water mixture, and then the complete decomposition of hydrate. Empirical potential structure refinement computer simulations are used to analyze the neutron diffraction data and extract from the data the water structure in the bulk methane hydrate solution. The results highlight the significant changes in the water structure of the remaining liquid at various stages of hydrate formation and decomposition, and give further insight into the way in which hydrates form. The results also have important implications on the memory effect, suggesting that the water structure in the presence of hydrate crystallites is significantly different at equivalent stages of forming compared to decomposing. These results are in sharp contrast to the previously reported cases when all remaining hydrate crystallites are absent from the solution. For these systems there is no detectable change in the water structure or the methane hydration shell before hydrate formation and after decomposition. Based on the new results presented in this paper, it is clear that the local water structure is affected by the presence of hydrate crystallites, which may in turn be responsible for the "history" or "memory" effect where the production of hydrate from a solution of formed and then subsequently melted hydrate is reportedly much quicker than producing hydrate from a fresh water/gas mixture. 相似文献
87.
J.J. Dubowski P.J. Poole G.I. Sproule G. Marshall S. Moisa C. Lacelle M. Buchanan 《Applied Physics A: Materials Science & Processing》1999,69(7):S299-S303
The influence of excimer-laser-assisted surface processing on quantum-well photoluminescence (QW PL) has been investigated in InGaAs/InGaAsP heterostructures capped with a thin layer of In0.53Ga0.47As. The PL mapping measurements carried out on samples before they were processed in a rapid thermal annealer indicated no significant differences in the QW PL signal intensity measured at the excimer-laser-processed sites and in their vicinity. However, a large difference in the QW PL signal, with its intensity significantly enhanced at the laser-processed sites, was observed after 10 s of rapid thermal annealing (RTA) at 750 °C. The largest contrast in the PL signal (an intensity difference up to about 100%) was obtained for a site processed with 50 pulses and a laser fluence of 123 mJ/cm2. The changes in the QW PL signal intensity have been found to coincide with the changes in the surface chemical composition that were detected with Auger electron spectroscopy. The main difference concerns the development of a GaOx layer on the laser-processed In0.53Ga0.47As surface. 相似文献
88.
McMahon SA Leonard GA Buchanan LV Giraud MF Naismith JH 《Acta crystallographica. Section D, Biological crystallography》1999,55(5):1108
In the paper by McMahon, Leonard, Buchanan, Giraud & Naismith [Acta Cryst. (1999). D55, 399-402] an author's error has resulted in the fifth sentence of the Abstract being incorrect. The sentence should read 'They are monoclinic, space group P21, with unit-cell dimensions a = 71.12, b = 58.42, c = 96.38 A, beta = 96.38 degrees. 92% (native) and 94% (selenomethionine) complete data sets have been recorded to 2.9 A (Rmerge = 5.0%) and 3.0 A (Rmerge = 6.9%), respectively.' 相似文献
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A. Breakstone C. D. Buchanan R. Campanini H. B. Crawley M. Dallavalle K. Doroba D. Drijard F. Fabbri A. Firestone H. G. Fischer H. Frehse W. Geist G. Giacomelli R. Gokieli M. Gorbics P. Hanke M. Heiden W. Herr E. E. Kluge J. W. Lamsa T. Lohse W. T. Meyer G. Mornacchi T. Nakada M. Panter A. Putzer K. Rauschnabel F. Rimondi R. Sosnowski M. Szczekowski O. Ullaland D. Wegener 《Zeitschrift fur Physik C Particles and Fields》1984,25(1):21-27
High energy proton-proton interactions yielding a single trigger particle with large transverse momentum give rise to a four-jet event structure with two transverse jets and two jets along the beam direction. The transverse jets are due to the fragmentation of point like scattered partons. It is shown that the quantum numbers of triggering charged pions and positive kaons are correlated with the flavour of the scattered parent parton; thus one can enhance data samples with a particular flavour of a scattered parton. The analysis, which is independent of detailed model calculations, exploits (a) the identification of the leading particles in the trigger jets (trigger particles), (b) the measurement of their relative production rates, (c) short range quantum number correlations within the trigger jets, and (d) long range correlations between leading particles from different jets. The data were obtained at \(\sqrt s \) =62 GeV with the Split Field Magnet detector at the CERN ISR. 相似文献