排序方式: 共有7条查询结果,搜索用时 234 毫秒
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Mohammad Mazloum Ardakani Pouran Pourhakak Masoud Salavati-Niasari 《Analytical sciences》2006,22(6):865-870
A coated-wire ion-selective electrode (CWISE), based on a Schiff base as a neutral carrier, was successfully developed for the detection of Pb(II) in aqueous solution. CWISE exhibited a linear response with a Nernstian slope of 29.4 +/- 0.5 mV/decade within the concentration range of 1.0 x 10(-5) - 1.0 x 10(-1) M lead ion. CWISE has shown detection limits of 5.0 x 10(-6) M. The electrode exhibited good selectivity over a number of alkali, alkaline earth, transition and heavy metal ions. This sensor yielded a steady potential within 10 to 20 s at a linear dynamic range. The electrode was suitable for use in aqueous solutions in a pH range of 2.0 to 5.0. Applications of this electrode for the determination of lead in real samples and as indicator electrode for potentiometric titration of Pb2+ ion using K2CrO4 are reported. 相似文献
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Film splitting necessarily occurs in roll coating and unwanted droplets can occur at high machine speeds when the resulting
filaments break up. To study this ‘misting’ problem, an apparatus was designed and built to simulate filament fluid mechanics.
The device creates a filament by elongating a liquid bridge and stretches the filament at a high and constant rate of acceleration
to mimic coating machine kinematics. Filament breakup was observed using a high-speed video camera and the images were analyzed
to yield droplet size and number. With Newtonian fluids, a single droplet formed at Ohnesorge (Oh) numbers less than 0.1 and
more and smaller droplets were produced at Oh numbers above 0.1. Associative polymer solutions, prepared as weakly elastic
fluids to represent industrial coatings, produced even more and smaller droplets, but only for Ohnesorge numbers in the range
of 0.01 to 0.1. 相似文献
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Murad Alim Sergio Cecotti Clay Córdova Sam Espahbodi Ashwin Rastogi Cumrun Vafa 《Communications in Mathematical Physics》2013,323(3):1185-1227
We study the BPS spectra of ${\mathcal{N}=2}$ N = 2 complete quantum field theories in four dimensions. For examples that can be described by a pair of M5 branes on a punctured Riemann surface we explain how triangulations of the surface fix a BPS quiver and superpotential for the theory. The BPS spectrum can then be determined by solving the quantum mechanics problem encoded by the quiver. By analyzing the structure of this quantum mechanics we show that all asymptotically free examples, Argyres-Douglas models, and theories defined by punctured spheres and tori have a chamber with finitely many BPS states. In all such cases we determine the spectrum. 相似文献
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A kinetic study of the electron-transfer in the reaction of tribenzylchlorotin with potassium 12-tungsto cobalt(Ⅲ) ate ion, K_5[CoW_(12)O_(40)],abbreviated as Co(Ⅲ)W,has been performed in different solvents.The studies were carried out in methanol, ethanol,acetonitrile and acetic acid/water.The rate constants,reaction rates and activation parameters were calculated. Our findings show that the rate of disappearance of the Co(Ⅲ) is pseudo-first order.The kinetic data is strongly affected by used solvents.T... 相似文献
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Ignatios Antoniadis Alexey Boyarsky Sam Espahbodi Oleg Ruchayskiy James D. Wells 《Nuclear Physics B》2010,824(1-2):296-313
Many extensions of the Standard Model (SM) predict new neutral vector bosons at energies accessible by the Large Hadron Collider (LHC). We study an extension of the SM with new chiral fermions subject to non-trivial anomaly cancellations. If the new fermions have SM charges, but are too heavy to be created at LHC, and the SM fermions are not charged under the extra gauge field, one would expect that this new sector remains completely invisible at LHC. We show, however, that a non-trivial anomaly cancellation between the new heavy fermions may give rise to observable effects in the gauge boson sector that can be seen at the LHC and distinguished from backgrounds. 相似文献
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