modern research physics

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Maize seedlings were treated with various concentrations of copper (25-100 µM) without EDTA and with EDTA for 120 hours. A sever and progressive decrease of root length and dry weight and an increase in K+ leakage with increasing Cu in nutrient solution was observed in the treated plants with Cu without EDTA. The roots accumulated significantly higher amounts of Cu than the shoot. With increasing Cu concentrations, amounts of Ca, Mg, K and Fe decreased in roots and in shoot. Application of EDTA with Cu caused increased dry weight and root length but decreased K+ leakage into nutrient solution. Application of EDTA increased Cu accumulation in roots but decreased it in shoot and caused a different effect on other minerals contents. Overall, EDTA could reduce copper toxicity in Maize seedlings.

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In this research, ac measurements of copper phthalocyanine thin film using aluminium electrodes are investigated in the frequency range 102 to 105 Hz and within the temperature range frequency and the capacitance and dissipation factor(loss tangent) decrease with increasing relative importance of the hopping model and band theory in describing the film condution with regard to the operating conditions. It was observed that the band theory is dominant at high frequencies and high temperatures, whereas hopping model is dominant at low frequencies. The energy gap of CuPc was determined using dc measurements.

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Productive and non-productive intrusive of Oligocene-Miocene age with similar mineralogical composition in Kerman porphyry copper belt exhibited important geochemical differences in terms of trace and rare earth element geochemistry. The productive intrusives are best characterized by low contents of MnO (&le0.1 wt.%), Y(&le18ppm), &SigmaHFSE (&le۱۰۰ppm), heavy rare earth elements (Yb&le1.9 ppm), high Sr content(&ge406-1015ppm), high (Sr/Y&ge30), significant REE fractionation (La/Yb&ge20), as well as positive Eu anomalies(Eu/Eu&ge1), when compared with non-productive intrusives(MnO&ge0.1wt.%,Sr=184-576ppm,Y=12-50ppm, Sr/Y<30, La/Yb<15,Eu/Eu*<1).These signatures are indicative of hydrous and oxidized magmas that formed in a condition which has been different from that of the non-productive intrusives. Based on the present study, the discrimination diagrams which can be used as a tool for identification of productive intrusives, where they are accompanied by nonproductive intrusives, in other copper provinces in Iran, are as follows: MnO-Y, &SigmaHFSE-Y, Sr/Y-Y, Sr/Y-SiO2 , La/Yb-SiO2, La/Yb-Yb, Eu/Eu*-SiO2.

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In this paper, we study the electronic transport of a multi-molecular chain of copper phthalocyanine connected to two metallic leads by using Green’s function method at the tight-binding approach. The results show that in the gaps of this system, the density of states is independent of the number of molecules or the system length. Moreover, increasing of the system length decreases the tunneling conductance and causes the appearance of peaks and dips in the gaps of the conductance spectra and depending on the value of incoming electron energy, the electron tunneling takes place easier, especially in the edges of the gaps.

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Effects of various CuCl2 trearments (0, 100, 300, 500 µM) at rosette stage on accumulation of Cu+2, Fe+2, Mg+2, and K+, and proline concentration in root and leaf of two canola (Brassica napus L.) cultivars (PF and Hyola) were studied under greenhouse conditions. In general, in response to copper chloride treatments, significant differences were observed between physiological behaviors of these cultivars. With increasing in CuCl2 concentration, the increases in copper and proline levels and decrease in Fe+2, Mg+2, and K+ concentrations were greater in PF (especially root) than that of Hyola. Thus, it seemed that PF had more ability against heavy metal stress, compared with Hyola. Therefore, from biochemical point of view, PF could be introduced as more tolerant cultivar to heavy metal stress, in comparison to Hyola.