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991.
ABSTRACTThe present paper reports the experimental investigation of pool boiling heat transfer on multiscale functionalized copper surfaces. Multiscale functionalized surfaces are fabricated by employing the nano-second laser surface process (NLSP) technique. The heat transfer coefficients (HTCs) of functionalized surfaces are estimated experimentally by using water and acetone as pool liquid. Tests are performed at atmospheric pressure, and saturated pool boiling condition with heat flux varyies between 0 and 330 kW/m2. The maximum HTCs for functionalized surface and reference polished surface were found to be 41,500 W/m2K and 23,000 W/m2K, respectively, with water and 22,000 W/m2K and 14,000 W/m2K, respectively, with acetone. 相似文献
992.
S. T. Cui 《Molecular physics》2013,111(19):2993-3001
We derive a simple analytical expression for the electric potential produced by a point charge in a cylindrical pore with relative permittivity different from that of the surrounding medium. The interface between the pore and the surrounding media may contain electric charge or be electrically neutral. The expression reduces to the known solutions when the surrounding dielectric medium is identical to the pore or an electric conductor. We discuss the convergence of the series expansion and numerically evaluate the electrostatic potential inside the cylindrical pore. The calculated potential shows the effect of the dielectric permittivity difference of the media. The results demonstrate that the expression can be implemented in a numerical dynamic simulation of charged systems in cylindrical geometry. We also give an expression for the case when the source charge is in the medium outside the cylinder. 相似文献
993.
N. Shashank Vikram Singh Sanjeev K. Gupta K. V. Madhu J. Akhtar R. Damle 《辐射效应与固体损伤》2013,168(4):313-322
Ni/SiO2/Si MOS structures were fabricated on n-type Si wafers and were irradiated with 50 MeV Li3+ ions with fluences ranging from 1×1010 to 1×1012 ions/cm2. High frequency C–V characteristics are studied in situ to estimate the build-up of fixed and oxide charges. The nature of the charge build-up with ion fluence is analyzed. Defect levels in bulk Si and its properties such as activation energy, capture cross-section, trap concentration and carrier lifetimes are studied using deep-level transient spectroscopy. Electron traps with energies ranging from 0.069 to 0.523 eV are observed in Li ion-irradiated devices. The dependence of series resistance, substrate doping and accumulation capacitance on Li ion fluence are clearly explained. The study of dielectric properties (tan δ and quality factor) confirms the degradation of the oxide layer to a greater extent due to ion irradiation. 相似文献
994.
We consider the case of a uniform plane conductor containing a thin curve-like inhomogeneity of finite conductivity. In this article we prove that the imperfection can be uniquely determined from the boundary measurements of the first order correction term in the asymptotic expansion of the steady state voltage potential as the thickness goes to zero. 相似文献
995.
Martin Griffiths 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1268-1273
In this article, we derive a number of identities involving both Pell numbers and binomial coefficients. We also consider briefly the potential for obtaining Pell identities involving trinomial coefficients and beyond. A key point is the simplicity of the derivations, and indeed this work can lead on to a number of interesting explorations for first-year undergraduates. 相似文献
996.
Shuai Zhai 《Journal of Number Theory》2013,133(11):3862-3876
Let denote the nth normalized Fourier coefficient of the classical holomorphic cusp form of even integral weight for the full modular group . In this paper, we investigate the average behavior of the power sum for , and . 相似文献
997.
Tiago Caúla Levi Lopes de Lima Newton Luis Santos 《Mathematische Nachrichten》2013,286(17-18):1752-1777
We present several deformation and rigidity results within the classes of closed Riemannian manifolds which either are 2k‐Einstein (in the sense that their 2k‐Ricci tensor is constant) or have constant 2k‐Gauss‐Bonnet curvature. The results hold for a family of manifolds containing all non‐flat space forms and the main ingredients in the proofs are explicit formulae for the linearizations of the above invariants obtained by means of the formalism of double forms. 相似文献
998.
Guangjun Zhu 《代数通讯》2013,41(11):4120-4131
Let (R,𝔪) be a Cohen–Macaulay local ring of dimension d > 0, I an 𝔪-primary ideal of R, and K an ideal containing I. When depth G(I) ≥ d ? 1, depth FK(I) ≥ d ? 2, and r(I|K) < ∞, we calculate the fiber coefficients fi(I). Under the above assumptions on depth G(I) and r(I|K), we give an upper bound for f1(I), and also provide a characterization, in terms of f1(I), of the condition depth FK(I) ≥ d ? 2. 相似文献
999.
Tianshui Ma 《代数通讯》2013,41(9):3206-3242
In this article, we first introduce the notion of a bitwistor and discuss conditions under which such bitwistor forms a bialgebra as a generalization of the well-known Radford's biproduct. Then, in order to obtain new quasitriangular bialgebras, we consider a construction called twisted tensor biproduct, which is a special case of bitwistor bialgebra, and give a necessary and sufficient condition for such twisted tensor biproduct to admit quasitriangular structures. 相似文献
1000.