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11.
Harun Karsli 《Mathematical Methods in the Applied Sciences》2019,42(16):5190-5198
The concern of this paper is to continue the investigation of convergence properties of nonlinear approximation operators, which are defined by Karsli. In details, the paper centers around Urysohn‐type nonlinear counterpart of the Bernstein operators. As a continuation of the study of Karsli, the present paper is devoted to obtain Voronovskaya‐type theorems for the Urysohn‐type nonlinear Bernstein operators. 相似文献
12.
We consider the initial value problem for the Klein‐Gordon equation in de Sitter spacetime. We use the central difference scheme on the temporal discretization. We also discretize the spatial variable using the finite element method with implicit and the Crank‐Nicolson schemes for the numerical solution of the initial value problem. In order to show the accuracy for the results of the solutions, we also examine the finite difference methods. We observe that the numerical results obtained by using these methods are compatible. 相似文献
13.
Nanosecond pulse generation in an erbium-doped fiber laser (EDFL) passively mode-locked by a silver nanoparticle(SNP)-based saturable absorber(SA) is experimentally demonstrated. The SA is fabricated by depositing a nanosized SNP layer onto the surface of polyvinyl alcohol film through the thermal evaporation process. By inserting the SA into an EDFL cavity, stable mode-locked operation is achieved at 1561.5 nm with the maximum pulse energy up to 52.3 nJ. The laser operates at a pulse repetition frequency of 1.0 MHz with a pulse width of 202 ns. These results suggest that SNPs could be developed as an effective SA for mode-locking pulse generation. 相似文献
14.
Norbert Polat 《Czechoslovak Mathematical Journal》2001,51(3):477-492
For an end and a tree T of a graph G we denote respectively by m() and m
T
() the maximum numbers of pairwise disjoint rays of G and T belonging to , and we define tm() := min{m
T(): T is a spanning tree of G}. In this paper we give partial answers — affirmative and negative ones — to the general problem of determining if, for a function f mapping every end of G to a cardinal f() such that tm() f() m(), there exists a spanning tree T of G such that m
T
() = f() for every end of G. 相似文献
15.
Norbert Polat 《Discrete Mathematics》2009,309(8):2119-2133
A graph G has the Median Cycle Property (MCP) if every triple (u0,u1,u2) of vertices of G admits a unique median or a unique median cycle, that is a gated cycle C of G such that for all i,j,k∈{0,1,2}, if xi is the gate of ui in C, then: {xi,xj}⊆IG(ui,uj) if i≠j, and dG(xi,xj)<dG(xi,xk)+dG(xk,xj). We prove that a netlike partial cube has the MCP if and only if it contains no triple of convex cycles pairwise having an edge in common and intersecting in a single vertex. Moreover a finite netlike partial cube G has the MCP if and only if G can be obtained from a set of even cycles and hypercubes by successive gated amalgamations, and equivalently, if and only if G can be obtained from K1 by a sequence of special expansions. We also show that the geodesic interval space of a netlike partial cube having the MCP is a Pash-Peano space (i.e. a closed join space). 相似文献
16.
Cesme Mustafa Polat Duygu Senel Pelin Golcu Aysegul 《Russian Journal of Electrochemistry》2019,55(4):281-290
Russian Journal of Electrochemistry - In this study, a new biosensor for amisulpride (ASP) determination is defined. The interaction between ASP and fish sperm double-stranded DNA (FSdsDNA) was... 相似文献
17.
A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V_2O_5) material as a saturable absorber(SA). The V_2O_5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm~2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz. 相似文献
18.
Ratiometric fluorescent chemosensors based on the position of ring annulation of the naphthol–thiazole moiety for quantification of zinc ions in aqueous ethanol were synthesized and investigated. It was found that sensor 3 exhibited a remarkably large red shift of 140 nm in emission upon complexation with Zn2+. A TD-B3LYP/6-31G (d,p) calculation was performed to characterize the nature of the fluorescence behavior of sensor 3 upon Zn2+ complexation. The combination of experimental and computational analyses provides a more complete understanding of the molecular level origin of these unique photophysical properties of this type of chemosensor. 相似文献
19.
An efficient gain-flattened C-band optical amplifier is demonstrated using a hybrid configuration with a Zirconia-based Erbium-doped
fibre (Zr-EDF) and a semiconductor optical amplifier (SOA). The amplifier utilizes a two-stage structure with a midway isolator
to improve flat gain characteristic and reduce noise figure. At input signal power of −30 dBm, a flat gain of 28 dB is obtained
from wavelength region of 1530 to 1560 nm with gain variation of less than 4 dB. The noise figure is maintained below 11 dB
at the flat-gain region. This amplifier has the potential to be used in the high channel count dense wavelength division multiplexing
system due to its simplicity and compact design. 相似文献
20.