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排序方式: 共有393条查询结果,搜索用时 8 毫秒
91.
Nasuha Siti Pershaanaa M. Bashir Shahid Ramesh K. Ramesh S. 《Journal of Solid State Electrochemistry》2022,26(8):1733-1746
Journal of Solid State Electrochemistry - Binary metal sulfide–based electrode materials with distinct nanoarchitecture, improved conductivities, and fascinating mechanical stabilities are... 相似文献
92.
M. Shahid Rafique Shazia Bashir Ali Ajami Wolfgang Husinsky 《Applied Physics A: Materials Science & Processing》2010,100(4):1183-1189
We have investigated femtosecond laser irradiation effects on the surface topography, structural changes and nonlinear absorption
properties of CR-39. For this purpose, a CR-39 target was exposed in air to 25 fs, 800 nm Ti: sapphire laser radiation at
fluences ranging from 0.25 J cm−2 to 3.6 J cm−2. The surface of irradiated CR-39 probed by an Atomic Force Microscope (AFM) exhibits the formation of several topographical
structures, like bumps, explosions and nano cavities. Raman spectroscopy is performed to explore chemical and structural modification
of the irradiated target. The spectroscopy reveals changes such as cross linking, bond breaking, formation of new bonds etc.
in the fundamental structure of the polymer after irradiation. In order to establish a correlation between morphological and
structural changes with the changes in the nonlinear absorption of the irradiated CR-39, a Z-scan technique was employed.
A comparison of experimentally obtained data from Z-scan measurements with our calculations predicts the dominance of three-photon
absorption in the case of pristine CR-39, whereas for irradiated targets concurrence of three- and two-photon absorption is
probable. Nonlinear absorption increases with increasing laser fluences and is well correlated by surface and structural changes
revealed by AFM and Raman spectroscopy. 相似文献
93.
AbstractIn the present paper, we focus on a stochastic predator-prey model with stage structure for prey. Firstly, by using the stochastic Lyapunov function method, we obtain sufficient conditions for the existence and uniqueness of an ergodic stationary distribution of the positive solutions to the model. Then we establish sufficient conditions for extinction of the predator population in two cases. Some examples and numerical simulations are carried out to validate our analytical findings. 相似文献
94.
Fractional order nonlinear mixed coupled systems with coupled integro-differential boundary conditions 下载免费PDF全文
Bashir Ahm Ahmed Alsaedi Sotiris K. Ntouyas 《Journal of Applied Analysis & Computation》2020,10(3):892-903
We study the existence and uniqueness of solutions for a class of coupled fractional differential equations involving both Riemann-Liouville and Caputo fractional derivatives, and coupled integro-differential boundary conditions. We derive the desired results with the aid of modern methods of functional analysis. An example illustrating the abstract results is also presented. 相似文献
95.
In this paper, we prove the existence and uniqueness of solutions for an anti-periodic boundary value problem of nonlinear impulsive differential equations of fractional order α∈(2,3] by applying some well-known fixed point theorems. Some examples are presented to illustrate the main results. 相似文献
96.
Saeed Ahmad Haseeba Sadaf Muhammad Altaf Helen Stoeckli-Evans Seerat-ur-Rehman Sarfaraz Ahmed Bashir 《Crystallography Reports》2013,58(5):692-696
Two mercury(II) complexes containing cyanide and, N,N′-diethylthiourea (detu) and N,N′-dipropylthiourea (dprtu) ligands, [(detu)2Hg(CN)2] (1) and [(dprtu)2Hg(CN)2] (2), respectively, have been prepared and characterized by X-ray crystallography. In the both complexes Hg atom lies on a 2-fold rotation axis, and is coordinated to the sulfur atoms of two thiourea ligands and to two cyanide carbon atoms. Both have a distorted tetrahedral environment with bond angles about the Hg atoms in the range of 93.41(4)°–146.75(19)°. In the crystal structures symmetry related molecules are linked via N-H-N hydrogen bonds resulting in the formation of a two-dimensional network in 1, while in 2 a double stranded one-dimensional chain is formed. 相似文献
97.
Necessary and sufficient conditions for oscillation of second‐order dynamic equations on time scales
Yong Zhou Bashir Ahmad Ahmed Alsaedi 《Mathematical Methods in the Applied Sciences》2019,42(13):4488-4497
In this paper, we establish necessary and sufficient conditions for oscillation of second‐order strongly superlinear and strongly sublinear dynamic equations. Our results unify and improve many known results in the literature. 相似文献
98.
In this paper, we present the sufficient conditions ensuring the instability of the zero solution of an impulsive state dependent delay integrodifferential system for different conditions on the delay function. We assume the instability of the associated linear impulsive system and apply the idea of dichotomies together with Schauder–Tychonoff theorem to establish the sufficient conditions for the unstable solution of the problem. 相似文献
99.
In this paper, we study the dynamics of a stochastic Susceptible-Infective-Removed-Infective (SIRI) epidemic model with relapse. By constructing a suitable stochastic Lyapunov function, we establish sufficient conditions for the existence of an ergodic stationary distribution to the model. Moreover, sufficient conditions for extinction of the disease are also obtained. 相似文献
100.
Farukh Arjmand Fatima Sayeed Shazia Parveen 《Journal of organometallic chemistry》2011,696(24):3836-3845
The chiral benzimidazole ligand, 1,2-Bis(1H-benzimidazol-2-yl)ethane-1,2-diol, L, exhibiting coordination mode with an oxygen atom of alcohol group directed towards the metal ion and another -OH group with different molecular axis directed away from the metal center was utilized as a building block for organotin complexes [C18H19N4O2SnCl], [C28H23N4O2SnCl] and [C52H42N4O2Sn2] (1-3). Complexes 1 and 3 exhibit a pentacoordinate geometry while the complex 2 reveals hexacoordinated environment around the Sn(IV) metal ions as evidenced by 119Sn NMR studies. The DNA binding ability of benzimidazole ligand and their organotin(IV) complexes 1-3 were examined by employing different biophysical methods. The absorption titration of the complexes with CT-DNA reveal significant hyperchromic effect together with strong bathochromic shift of 4-5 nm which infer substantial binding of the complexes with CT-DNA. The intrinsic binding constant Kb values of the complexes 1-3 were found to be 2.16 ± 0.04 × 104, 3.47 ± 0.04 × 104 and 4.60 ± 0.04 × 103 M−1, respectively, suggesting pronounced binding of complex 2 with DNA double helix. The mechanism of binding of the complexes was further ascertained by the interaction studies of these complexes with nucleotides (5′-GMP and 5′-TMP) using absorption spectroscopy suggesting a clear preference for 5′-GMP binding which was further authenticated by NMR (1H and 31P NMR) studies. 相似文献