This paper deals with a complex third order linear measure differential equation id(y')~·+ 2 iq(x)y'dx + y(idq(x) + dp(x)) = λydx on a bounded interval with boundary conditions presenting a mixed aspect of the Dirichlet and the periodic problems. The dependence of eigenvalues on the coefficients p and q is investigated. We prove that the n-th eigenvalue is continuous in p and q when the norm topology of total variation and the weak*topology are considered. Moreover, the Fr′echet differentiability of the n-th eigenvalue in p and q with the norm topology of total variation is also considered. To deduce these conclusions, we investigate the dependence of solutions of the above equation on the coefficients p and q with different topologies and establish the counting lemma of eigenvalues according to the estimates of solutions. 相似文献
Journal of Solid State Electrochemistry - Ultraflexible, wearable, transparent, and conductive films have recently attracted increasing interest due to their applicability in various electronic... 相似文献
Majority of previous solid ignition models, including numerical and analytical ones, considered only surface absorption of incident heat flux for simplification. However, the influence of in-depth absorption on pyrolysis and subsequent ignition cannot be ignored for infrared translucent polymers. This work addresses this problem and focuses on time-dependent heat flux to establish an analytical model for ignition behaviors prediction by means of theoretical analysis. Ignition temperature was utilized as the ignition criterion, and both surface and in-depth absorption scenarios were considered. Thermally thick polymethyl methacrylate and polyamide 6 were selected as reference materials to verify the reliability and applicability of the proposed model by comparing the analysis results with experimental data as well as numerical simulations. A method for determining the approximation parameters of the theoretical analysis was presented to derive the relationship between ignition time and the coefficients in heat flux expressions. The results show that the higher surface temperature owing to surface absorption accelerates the pyrolysis rate and results in a shorter ignition time, while in-depth absorption affects the ignition time inversely. The effect of surface heat loss was also evaluated quantitatively through both analytical and numerical models. The uncertainty of the proposed model is mainly caused by the selection of the approximation parameters. Nevertheless, it provides an alternative approach to estimate the ignition time of translucent polymers besides numerical simulation.
SnSe2, a novel 2D semiconducting material with good photoelectric properties and tunable bandgaps structure, has been widely studied in high-performance photodetectors and superconductivity applications, etc. Herein, another excellent property, nonlinear optical absorption, is applied to ultrafast photonics. The measured nonlinear optical absorption curve of SnSe2 with modulation depth of 5.52% is obtained. Q-switching and mode-locking in Er-doped fiber lasers based on SnSe2 is reported. A Q-switched fiber laser can be obtained with a 0.5-m-long gain fiber and a 50:50 optical coupler. With 0.75-m-long active fiber and a 40:60 optical coupler, mode locking can be obtained. Furthermore, a third-order bound-state soliton pulse with a pulse duration of 882 fs can be achieved. The experimental results show that SnSe2 is an excellent optical saturable absorber for the applications of ultrafast photonics. 相似文献
Infrared (IR) imaging and Raman chemical imaging have advantages over conventional methods to investigate heterogeneous plant structures in providing quantitative and qualitative analyses with the spatial distribution of the components. Combined with multivariate statistical analysis, they have been proven to be powerful nondestructive analytical tools in applications in plant materials. This review aims to present a general perspective about IR imaging and Raman chemical imaging in plant materials. The first section will introduce a variety of characteristics with the underlying principles, respectively. And the second section will review selected application in the latest literature, such as discrimination of different plant samples, investigation of the microstructures of leaf, identification of the cell wall components, and study of the microstructure and quality of cereal grains. And the last section is conclusion. 相似文献
The interaction between hyperoside and bovine serum albumin (BSA) was examined by fluorescence spectroscopy at 298, 304, and 310 K. The spectroscopic data were analyzed using Tachiya model and Stern–Volmer equation to determine the binding sites and apparent binding constant between hyperoside and BSA. For Tachiya model, both binding sites and apparent binding constants increased with the increasing of temperature, whereas for Stern–Volmer equation, the corresponding binding constants decreased as temperature increasing and the binding sites were independent of temperature. The positive sign of enthalpy change (ΔH) and entropy change (ΔS) suggested that hydrophobic forces played a major role in the interaction. Synchronous fluorescence spectra indicated that the conformation of protein was perturbed by the interaction of hyperoside with BSA. Moreover, the presence of metal ion affected the hyperoside-BSA binding. 相似文献
The maximal tolerance parameters of poling period and phase-matching, temperature in second harmonic generation (SHG) using periodically poled RbTiOAsO4(PPRTA) as a function of the fundamental wavelength are investigated theoretically. The tolerance of the poling period ΔΛ of PPRTA is found larger than that of PPLN and PPKTP when the fundamental wavelength is beyond 2 μm, which reaches its maximum ΔΛmax for PPRTA at a fundamental wavelength of 2.7433 μm. However, the tolerance for the phase-matching temperature ΔT of PPRTA is found smaller than that of PPLN and PPKTP with an exception that PPRTA has a larger tolerance of the temperature or a larger temperature phase-matching bandwidth at fundamental wavelength of 2.2474 μm, where the maximum of ΔT(ΔTmax) is obtained. Furthermore, the tuning characteristics of the optical parametric processes using PPRTA for collinear quasi-phase-matching (CQPM) is analyzed. The combination of temperature tuning and poling period tuning enables a quasi-continuous wavelength tuning range of 1493.2-1593.7 nm for the signal and 3201.8-3699.2 nm for the idler, where poling period of 39 μm, 39.5 μm and 40 μm and a temperature between 20 and 120° have been employed in the corresponding theoretical analysis. 相似文献
M?ller-Plesset perturbation theory and density functional theory calculations are used to study decomposition mechanisms of polymerization initiators, such as diethyl peroxydicarbonate, trifluoroacetyl peroxide, and acetyl peroxide, which possess a general structure of RC(O)OO(O)CR. It is found that the decomposition of initiators with electron-donating R groups follows two favorable stepwise pathways: a two-bond cleavage mechanism in which the O-O single bond and one of R-C bonds of [R-C(O)O-O(O)C-R] break simultaneously followed by decomposition of the R-C(O)O(*) radical and a one-bond cleavage mechanism in which the single O-O bond cleavage produces a carboxyl radical pair and a subsequent decomposition of the carboxyl radicals. It is also found that the initiators with electron-withdrawing R groups follow the two-bond cleavage pathway only. Geometrical and energetic analyses indicate that despite the similar structures of the peroxydicarbonates, quite different decomposition energy barriers are determined by the nature of the R groups. 相似文献