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71.
Mechanics of Composite Materials - The optimal stochastic distribution of carbon nanotubes (CNTs) in nanoreinforced polymer composite of a cantilevered microbeam is investigated. Finite-element... 相似文献
72.
In this paper we are interested in a technique for solving some nonlinear rational systems of difference equations of third order, in three-dimensional case. Moreover, we study the periodicity of solutions for such systems. Finally, some numerical examples are presented. 相似文献
73.
The base-catalyzed isomerization of simple aryl halides is presented and utilized to achieve the 4-selective etherification, hydroxylation and amination of 3-bromopyridines. Mechanistic studies support isomerization of 3-bromopyridines to 4-bromopyridines proceeds via pyridyne intermediates and that 4-substitution selectivity is driven by a facile aromatic substitution reaction. Useful features of a tandem aryl halide isomerization/selective interception approach to aromatic functionalization are demonstrated. Example benefits include the use of readily available and stable 3-bromopyridines in place of less available and stable 4-halogenated congeners and the ability to converge mixtures of 3- and 5-bromopyridines to a single 4-substituted product.The base-catalyzed isomerization of aryl halides is described and applied to the tandem isomerization/4-substitution of 3-bromopyridines as a strategy for achieving unconventional selectivity in nucleophilic aromatic substitution reactions. 相似文献
74.
Fatimah Mohammed Alzahrani Norah Salem Alsaiari Khadijah Mohammedsaleh Katubi Abdelfattah Amari Abubakr M. Elkhaleefa Faouzi Ben Rebah Mohamed A. Tahoon 《Molecules (Basel, Switzerland)》2021,26(16)
We report in the present study the in situ formation of magnetic nanoparticles (Fe3O4 or Fe) within porous N-doped carbon (Fe3O4/N@C) via simple impregnation, polymerization, and calcination sequentially. The synthesized nanocomposite structural properties were investigated using different techniques showing its good construction. The formed nanocomposite showed a saturation magnetization (Ms) of 23.0 emu g−1 due to the implanted magnetic nanoparticles and high surface area from the porous N-doped carbon. The nanocomposite was formed as graphite-type layers. The well-synthesized nanocomposite showed a high adsorption affinity toward Pb2+ toxic ions. The nanosorbent showed a maximum adsorption capacity of 250.0 mg/g toward the Pb2+ metallic ions at pH of 5.5, initial Pb2+ concentration of 180.0 mg/L, and room temperature. Due to its superparamagnetic characteristics, an external magnet was used for the fast separation of the nanocomposite. This enabled the study of the nanocomposite reusability toward Pb2+ ions, showing good chemical stability even after six cycles. Subsequently, Fe3O4/N@C nanocomposite was shown to have excellent efficiency for the removal of toxic Pb2+ ions from water. 相似文献
75.
Pratibha Pandey Fahad Khan Faisal Abdulrahman Alzahrani Huda A. Qari Mohammad Oves 《Molecules (Basel, Switzerland)》2021,26(18)
Rutin has been well recognized for possessing numerous pharmacological and biological activities in several human cancer cells. This research has addressed the inhibitory potential of rutin against the Jab1 oncogene in SiHa cancer cells, which is known to inactivate various tumor suppressor proteins including p53 and p27. Further, the inhibitory efficacy of rutin via Jab1 expression modulation in cervical cancer has not been yet elucidated. Hence, we hypothesized that rutin could exhibit strong inhibitory efficacy against Jab1 and, thereby, induce significant growth arrest in SiHa cancer cells in a dose-dependent manner. In our study, the cytotoxic efficacy of rutin on the proliferation of a cervical cancer cell line (SiHa) was exhibited using MTT and LDH assays. The correlation between rutin and Jab1 mRNA expression was assessed by RT-PCR analysis and the associated events (a mechanism) with this downregulation were then explored via performing ROS assay, DAPI analysis, and expression analysis of apoptosis-associated signaling molecules such as Bax, Bcl-2, and Caspase-3 and -9 using qRT-PCR analysis. Results exhibit that rutin produces anticancer effects via inducing modulation in the expression of oncogenes as well as tumor suppressor genes. Further apoptosis induction, caspase activation, and ROS generation in rutin-treated SiHa cancer cells explain the cascade of events associated with Jab1 downregulation in SiHa cancer cells. Additionally, apoptosis induction was further confirmed by the FITC-Annexin V/PI double staining method. Altogether, our research supports the feasibility of developing rutin as one of the potent drug candidates in cervical cancer management via targeting one such crucial oncogene associated with cervical cancer progression. 相似文献
76.
YuXiao Jiang PengLiang Guo ChengYan Gao HaiBo Wang Faris Alzahrani Aatef Hobiny FuGuo Deng 《中国科学:物理学 力学 天文学(英文版)》2017,60(12):120312
We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom. 相似文献
77.
This study involved the utilization of a free radical-graft copolymerization reaction for the development of a novel adsorbent, namely, poly(butyl methacrylate)-grafted alginate/Fe3O4 nanocomposite (PBMA-gft-Alg/Fe3O4). Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction patterns analysis, and Fourier transform infrared spectroscopy (FT-IR) were carried out for the characterization of Fe3O4 NPs and PBMA-gft-Alg/Fe3O4 nanocomposites. The capability of nanocomposites and nanoparticles to adsorb dyes such as MG and MB, resulting in their removal from aqueous media, was evaluated under different conditions such as pH, temperature, contact time, and dose of adsorbent. Optimum parameters for adsorption of dyes were found to be pH of 10, 50°C, contact time of 180 min, and 0.2 g of adsorbent. Efficiency of the PBMA-gft-Alg/Fe3O4 nanocomposite was found to be significantly greater than that of Fe3O4 NPs for eliminating the desired dye. Langmuir, Freundlich, Sips, and Temkin models were used for testing the experimental data. Freundlich model was the one that best described the adsorption. 相似文献
78.
Zi-Hang Wang Wen-Xuan Yu Xiao-Yuan Wu Cheng-Yan Gao Faris Alzahrani Aatef Hobiny Fu-Guo Deng 《International Journal of Theoretical Physics》2018,57(3):664-673
We present two different hyperentanglement concentration protocols (hyper-ECPs) for two-photon systems in nonlocal polarization-time-bin hyperentangled states with known parameters, including Bell-like and cluster-like states, resorting to the parameter splitting method. They require only one of two parties in quantum communication to operate her photon in the process of entanglement concentration, not two, and they have the maximal success probability. They work with linear optical elements and have good feasibility in experiment, especially in the case that there are a big number of quantum data exchanged as the parties can obtain the information about the parameters of the nonlocal hyperentangled states by sampling a subset of nonlocal hyperentangled two-photon systems and measuring them. As the quantum state of photons in the time-bin degree of freedom suffers from less noise in an optical-fiber channel, these hyper-ECPs may have good applications in practical long-distance quantum communication in the future. 相似文献
79.
In this paper, the fractional order theory has been applied for thermal, elastic and plasma waves to determine the carrier density, displacement, temperature and stress in a semiconductor medium. The thermal, elastic and plasma waves in a semi-infinite medium photogenerated by a focused laser beam were analyzed. The Laplace transformation is used to express the governing equation and solved analytically by applying eigenvalue approach methodology in that domain. A semiconducting material like as silicon was considered. According to the numerical results and graphics, the fractional order parameter and thermal relaxation time may play an important role in the behavior of all physical quantities. 相似文献
80.
Applying the electron-beam preirradiation method in air the cation - exchange fabric (CEF) containing sulfonic acid (R-SO3H) groups was prepared by graft copolymerization of sodium styrenesulfonate with acrylic acid onto non woven polypropylene fabric. The effect of reaction conditions on the grafting yield and reaction mechanism was examined. The ion-exchange properties towards Cu(II) and Co(II) ions of the CEF were investigated depending on the form of the CEF and a pH of the solution. It was found that the synthesized CEF contains both strong acid groups (R-SO3H) and weak acid (R-COOH) groups in almost equal proportion. The utilization of the CEF in Na+ form allows to make the best use of its ion-exchange capacity. 相似文献