45 resultados para STANDARD AUTOMATED PERIMETRY


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Association for Computing Machinery, ACM; IEEE; IEEE Computer Society; SIGSOFT

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In the present work a nonmonotonic dependence of standard rate constant (k(0)) on reorganization energy (lambda) was discovered qualitatively from electron transfer (Marcus-Hush-Levich) theory for heterogeneous electron transfer processes on electrode surface. It was found that the nonmonotonic dependence of k(0) on lambda is another result, besides the disappearance of the famous Marcus inverted region, coming from the continuum of electronic states in electrode: with the increase of lambda, the states for both Process I and Process II ET processes all vary from nonadiabatic to adiabatic state continuously, and the lambda dependence of k(0) for Process I is monotonic thoroughly, while for Process II on electrode surface the lambda dependence of k(0) could show a nonmonotonicity.

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It is important to detect the aromaticity of structures during the process of structure elucidation and output. In this paper, an alogrithm was proposed to detect the aromaticity of structures by the use of algorithm on ring identification. The results show that it could be used to identify most of the aromatic structure. It have been used as constraints of Expert System on Elucidation Structure of Organic Compounds(ESESOC) and a good result has been achieved.

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A method for the analysis of mussel standard reference material by inductively coupled plasma atomic emission spectrometry( ICP-AES) and inductively coupled plasma mass spectrometry(ICP-MS) was developed. K, Na, Ca, Mg, P, Al, Fe, Zn, Mn and Sr were determined by ICP-AES and As, B, Cd, Co, Cr, Cu, Ga, Ge, Mn, Mo, Ni, Pb, Se, Sr, U and V by ICP-MS, The interference coefficients at the Mn-55, Se-78, Cu-63, Co-59, Ni-58, Ni-60, As-75, Se-77, V-51, Cr-53 and Cr-52 originating from polyatomic ion of the matrix elements (KO)-K-39-O-16, K-39(2), (ArNa)-Ar-40-Na-23, (CaO)-Ca-43-O-16, (CaO)-Ca-42-O-16, (CaO)-Ca-44-O-16, (PO2)-P-31-O-16, (ArCl)-Ar-40-Cl-35, (ArCl)-Ar-40-Cl-37, (ClO)-Cl-35-O-16, (ClO)-Cl-37-O-16 and (ArC)-Ar-40-C-12 were determined under the selected operation parameters. The major matrix elements, such as K, Na and Ca, result in the suppression of analytes signals. The apparent concentration at the significant biological element which was produced by the different digestion methods, (.) HNO3 + H2O2 (3 + 2), HNO3 + HClO4 (3 + 0.5) and HNO3 + H2SO4 (3 + 0.5),was determined. The sample digested by HNO3 + H2O2 did not give rise to interfere on the analyte, and the backgrounds of Se-77, Ga-69, Zn-67, As-75, V-51, Cr-53 and Cr-52 were increased by HNO3 + HClO4 digestion method, that affected the determination of these elements, especially the monoisotope As and V. Sample digested by HNO3 + H2SO4 increased the backgrounds at Cu-65, Zn-64 and Zn-67. Detection limits of ICP-AES are 0.001 similar to 0.75 mg/L and those of ICP-MS are 0.005 similar to 1.01 mu g/L. The relative standard derivations of ICP-AES and ICP-MS are 2.7% similar to 12.8%, 3.4% similar to 24.8%, respectively.

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Measurement of iron and manganese is very important in evaluating the quality of natural waters. We have constructed an automated Fe(II), total dissolved iron(TDI), Mn(II), and total dissolved manganese(TDM) analysis system for the quality control of underground drinking water by reverse flow injection analysis and chemiluminescence detection(rFIA-CL), The method is based on the measurement of the metal-catalyzed light emission from luminol oxidation by potassium periodate. The typical signal is a narrow peak, in which the height is proportional to light emitted and hence to the concentration of metal ions. The detection limits were 3 x 10(-6) mu g ml(-1) for Fe(II) and the linear range extents up to 1.0 x 10(-4) and 5 x 10(-6) mu g ml(-1) for Mn(II) cover a linear range to 1.0 x 10(-4) mu g ml(-1). This method was used for automated in-situ monitoring of total dissolved iron and total dissolved in underground water during water treatment. (C) 1997 Elsevier Science B.V.

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The steady state voltammogram at a microdisk electrode is used to measure the diffusion coefficient and standard heterogeneous rate constant (k(s)) of ferrocene in polyelectrolyte PEG + LiClO4. The k(s) obtained is smaller in polyelectrolyte than in liquid medium. It is proposed that the polymer solvent electron transfer dynamics are affected by the relaxation rates of the ether dipole sites on the polymer chains, which are in turn constrained by the rates of polymer chain segment, or local structure, relaxations. The dependence of k(s) on temperature is observed. The k(s) increases with increasing temperature.

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The emfs of Cu|CuSO_4|Hg_2SO_4-Hg were determined at 5 temperature points from 278.15K to 313.15K. Based on the Pitzer' s Equation a polynomial approximation for the determination of standard emf, E_m, was proposed. The values of E_m obtained by author's method agree with values of E_m obtained by the extended Debye-Huckel equation within experimental errors. Compared with the extrapolation result of extended Debye-Huckel equation, the uncertainty by the selecting of parameter of ion size was avoided.By the...

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The small mysid crustacean Neomysis awatschensis was collected in the west coast of Jiaozhou Bay, Qingdao, China in 1992 and acclimated and cultured in laboratory conditions since then. Standard acute toxicity tests using 4-6 d juvenile mysids of this species were conducted and the results were compared with Mysidopsis bahia, a standard toxicity test organism used in the US in terms of their sensitivities to reference toxins, as well as their taxonomy, morphology and geographic distributions. Because of its wide distribution along the Chinese coast, similar sensitivity to pollutants as M. bahia, short life history, small size and the case of handling, this study intended to use N. awatschensis as one of the standard marine organisms for toxicity testing in China. The species were applied to acute toxicity evaluations of drilling fluid and its additives I organotin TPT and toxic algae, and to chronic ( life cycle) toxicity assays of organotin TPT and a toxic dinofalgellate Alexandrium tamarense, respectively. Using N, awatschensis as a standard toxicity testing organism in marine pollution assessment in China is suggested.