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This paper reports the fuel cells (DMFC and PEMFC) performance using sulfonated poly(arylene ether ether nitrile) (SPAEEN) copolymers containing sulfonic acid group arranged in structurally different ways. The membrane electrode assembly (MEA) fabricated from SPAEEN containing 60 mol% of angled naphthalenesulfonic acid group (m-SPAEEN-60) had superior performance over those derived from pendent naphthalenesulfonic acid group (p-SPAEEN) or sulfonated hydroquinone (HQ-SPAEEN) in H2/air and/or DMFC conditions. For example, the current density of the MEA using m-SPAEEN-60 at 0.5 V and 2.0 M methanol was 250 mA/cm2, whereas the current densities of the MEAs using p-SPAEEN-50 and HQ-SPAEEN-56 were 185 and 190 mA/cm2, respectively. In addition, compared with the sulfonated polysulfone (BPSH-35) and Nafion membranes, the copolymer containing nitrile group showed the improved cell performance. For example, the power density of the MEA using m-SPAEEN-60 at 250 mA/cm2 and 2.0 M methanol was 125 mW/cm2, whereas the power densities of the MEAs using sulfonated polysulfone (BPSH-35) and Nafion were 115 and 113 mW/cm2, respectively. m-SPAEEN-60 showed stable cell performance during extended operation (>100 h). 相似文献
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KM Varier AM Vinodkumar NVSV Prasad PV Madhusudhana Rao DL Sastry Lagy T Baby MC Radhakrishna NG Puttaswamy JJ Das P Sugathan N Madhavan AK Sinha DO Kataria 《Pramana》1999,53(3):529-533
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
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We propose a picture of Wigner function scars as a sequence of concentric rings along a two-dimensional surface inside a periodic orbit. This is verified for a two-dimensional plane that contains a classical hyperbolic orbit of a Hamiltonian system with 2 degrees of freedom. The stationary wave functions are the familiar mixture of scarred and random waves, but the spectral average of the Wigner functions in part of the plane is nearly that of a harmonic oscillator and individual states are also remarkably regular. These results are interpreted in terms of the semiclassical picture of chords and centers. 相似文献
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Özge Pala Dirk J Vriens Jac AM Vennix 《The Journal of the Operational Research Society》2015,66(4):593-601
Escalation of commitment, the tendency of decision makers to keep on investing in losing courses of action, has been shown to be a costly decision bias that affects many areas of decision making. Even though escalation is a widely studied phenomenon, there has been comparatively little research on how to avoid this bias. The present study focuses on de-escalation of commitment and proposes that causal loop diagrams (CLDs) can help to decrease escalating commitment to a failing course of action. By means of an experiment, this study shows that using a CLD decreases escalation tendencies. 相似文献
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Toledano P Figueiredo Neto AM de Sant'Ana ZA 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):486-492
Experimental investigations of lyotropic cholesterics fluids are presented which show that changes in the shape anisotropy and chirality of the micellar population determine the topology of the temperature-concentration phase diagrams. For given amounts of the substances which induce the chirality and modify the shape anisotropy of the micelles, two distinct biaxial cholesteric phases are disclosed in the phase diagrams. This is interpreted in the framework of the catastrophe theory of phase transitions. 相似文献