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71.
Hazeghi Farzaneh Mozaffari Samaneh Ghorashi Seyed Mohammad Bagher 《Journal of Solid State Electrochemistry》2020,24(6):1427-1438
Journal of Solid State Electrochemistry - Cu-Ni bimetallic organic frameworks were synthesized by a facile and stepwise solvothermal method, utilizing metal organic framework as precursor.... 相似文献
72.
Anti-icing performance of superhydrophobic surfaces 总被引:6,自引:0,他引:6
This article studies the anti-ice performance of several micro/nano-rough hydrophobic coatings with different surface chemistry and topography. The coatings were prepared by spin-coating or dip coating and used organosilane, fluoropolymer or silicone rubber as a top layer. Artificially created glaze ice, similar to the naturally accreted one, was deposited on the nanostructured surfaces by spraying supercooled water microdroplets (average size ∼80 μm) in a wind tunnel at subzero temperature (−10 °C). The ice adhesion strength was evaluated by spinning the samples in a centrifuge at constantly increasing speed until ice delamination occurred. The results show that the anti-icing properties of the tested materials deteriorate, as their surface asperities seem to be gradually broken during icing/de-icing cycles. Therefore, the durability of anti-icing properties appears to be an important point for further research. It is also shown that the anti-icing efficiency of the tested superhydrophobic surfaces is significantly lower in a humid atmosphere, as water condensation both on top and between surface asperities takes place, leading to high values of ice adhesion strength. This implies that superhydrophobic surfaces may not always be ice-phobic in the presence of humidity, which can limit their wide use as anti-icing materials. 相似文献
73.
Development of a cloud point extraction and preconcentration method for silver prior to flame atomic absorption spectrometry 总被引:1,自引:0,他引:1
The possibility was investigated of using 2-mercaptobenzothiazole (MBT) for Ag(I) concentration by micellar extraction at
cloud point (CP) temperature and subsequent determination by flame atomic absorption spectrometry (FAAS). The method is based
on the complexation of Ag(I) with 2-mercaptobenzothiazole (MBT) in the presence of non-ionic micelles of Triton X-114. The
effect of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and
time on cloud point extraction was studied. Under the optimum conditions, the preconcentration of 10 mL of water sample in
the presence of 0.1% Triton X-114 and 2 × 10−4 mol L−1 2-mercaptobenzothiazole permitted the detection of 2.2 ng mL−1 silver. The calibration graph was linear in the range of 10–200 ng mL−1, and the recovery of more than 99% was achieved. The proposed method was used in FAAS determination of Ag(I) in water samples. 相似文献
74.
AliReza Nowroozi Haidar Raissi Farzaneh Farzad 《Journal of Molecular Structure》2005,730(1-3):161-169
All the plausible conformations of β-aminoacrolein (AMAC) have been investigated by the Bekes-Lee-Yang-Parr (B3LYP) nonlocal density functional with extended 6-311++G** basis set for studying the stability order of conformers and the various possibilities of intramolecular hydrogen bonding formation. In general the ketoamine (KA) conformers of AMAC, by mean average, are more stable than the corresponding enolimine (EI) and ketoimine (KI) analogues and this stability is mainly due to the π-electron resonance in these conformers that established by NH2 functional group. The contribution of resonance to the stability of chelated KA conformers is about 75.6 kJ/mol, which is greater than that of the hydrogen bond energy (EHB=35.0 kJ/mol). The relative decreasing order of the various hydrogen bond energies was found to be: O–HNimine(strong)>Namine-HOketo (normal)>Nimine-HOhydroxyl (weak) > Nimine-HOketo (weak). Hydrogen bond energies for all systems were obtained from the method that we called related rotamers method (RRM). The topological properties of the electron density contributions for various type of intramolecular hydrogen bond have been analyzed in term of the Bader theory of atoms in molecules (AIM). The results of these calculations support the previous calculations, which obtained by the related rotamer methods. 相似文献
75.
Periodica Mathematica Hungarica - Let $$\mathcal {A}$$ be a von Neumann algebra acting on the complex Hilbert space $$\mathcal {H}$$ and $$\Phi {:}\,\mathcal {A} \longrightarrow \mathcal {A}$$ be a... 相似文献
76.
A computational technique based on the Müntz polynomials and meshless method has been presented for the solution of nonlinear and linear space fractional partial differential equations (PDEs). The meshless method that is used in this study is the new version of backward substitution method (BSM). First, the time-derivative term is discretized by the Crank-Nicolson method. Then, the approximate solution is given as the separation of the approximation of the boundary data and the correcting functions using the Müntz polynomials. In general form, this approximate solution that does not necessarily satisfy the original equation is shown as the sum of the system basics in which it consists free parameters. Finally, these parameters are determined by the BSM method inside the domain. The main advantage of the method is efficiency and reliability that is examined by six numerical experiments. 相似文献
77.
Noushine Shahidzadeh Mohamed M. Chehimi Farzaneh Arefi-Khonsari Jacques Amouroux Michel Delamar 《Plasmas and Polymers》1996,1(1):27-45
Acid-base properties of ammonia plasma-treated polypropylene (APTPP) were characterized by X-ray photoelectron spectroscopy
(XPS) in conjunction with the molecular probe technique and using chloroform (TCM) as a reference Lewis acid. It is shown
that TCM is retained by the basic surfaces of APTPP but not by the untreated PP. The retention of TCM is shown to be entirely
due to the formation of TCM:APTPP acid-base complexes. This is supported by the C12p3/2 binding energy (BE) and the shape of the Cl2p peak from the adsorbed TCM. ΔHAB, the heat of TCM:APTPP acid-base interaction was found to be in the range of 3.1–4.3 kcal/mol using a published Cl2p3/2 BE−ΔHAB correlation. This ΔHAB compares remarkably well with the values of 4.3–4.9 kcal/mol determined for TCM:amine complexes, and shows indeed that TCM
is complexed by nitrogen containing basic groups grafted at the surface. However, the TCM/N ratio has an optimal value up
to 1 second of plasma treatment and then decreases sharply, showing that less specific interaction sites are accessible at
the surface for longer treatment times. This parallels previous findings about the metallization of APTPP by aluminium which
was found to be optimal for treatment times lower than 1 second in our experimental conditions. This work shows that XPS can
now indeed be used to quantitatively assess the acid-base properties of modified polymer surfaces. 相似文献
78.
Physical and thermodynamic properties have been calculated and analyzed for the best and optimized geometries of the 3‐D clusters with N = 3 to N = 10 atoms and unit cells of three types of crystalline systems using ab initio RHF/6–31G** method. Dependence of the lattice binding energy on the cluster parameter, R, has been studied. Similar behavior observed for the binding energies for all clusters shows that probabilities of their existence in the condensed phase are more or less the same. In the next step, thermodynamic properties have been calculated and analyzed for He27 3‐D helium clusters with simple cubic, body centered cubic (bcc), trigonal and hexagonal (hcp) configurations. The results show that the hexagonal cluster is more favored over other clusters. It is found that these clusters are electronically stable over a limited range of the values for the lattice parameter. ΔfH is constant in this stability region and thus the ΔfG exactly follows the variations of TΔfS. Surface effects have been investigated by comparing the square and hexagonal He9 2‐D lattices with the cubic and hexagonal He27 3‐D lattices, respectively. The lattice parameters, densities and molar volumes calculated for the clusters with hcp and bcc configurations have satisfactory agreement with the available experimental values. Properties of the He13, He34 and He104 hcp clusters have also been calculated and analyzed. 相似文献
79.
Majid Masteri-Farahani Faezeh Farzaneh Mehdi Ghandi 《Reaction Kinetics and Catalysis Letters》2008,95(2):379-384
The sythesis, characterization and catalytic activity of WO2pypr [N,N′-bis (2-pyrrolmethlidenaminopropyl) amine] complexed to MCM-41 surface in the epoxidation of some alkenes with excellent
selectivity toward the corresponding epoxides is described in this presentation. 相似文献
80.