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91.
Heidari Behzad Shiroud Cheraghchi Vajiheh-Sadat Motahari Siamak Motlagh Ghodratollah Hashemi Davachi Seyed Mohammad 《Journal of Sol-Gel Science and Technology》2018,88(1):236-248
Journal of Sol-Gel Science and Technology - Resorcinol formaldehyde (RF) xerogel was modified by mercapto functional groups for removal of Pb(II) and Cu(II) ions from aqueous solutions. The... 相似文献
92.
93.
Wojciech P. Oziminski Tadeusz M. Krygowski Siamak Noorizadeh 《Structural chemistry》2012,23(3):931-938
Geometry of pentafulvene’s complexes with the atoms of the first group of Periodic Table (Li, Na, K, Rb, and Cs) are optimized
at the B3LYP/6-311 ++G(d, p) level of theory. Two kinds of complexes are considered: (1) those which are in equilibrium geometry,
and (2) complexes which are formed by gradual change in the distance between the metal atom and penta-fulvene ring. Aromaticities
of the considered complexes in their equilibrium geometries are investigated using different indices included geometry-based
(HOMA), magnetism-based (NICS, NICS(1), and NICS(1)zz), π-electron count-based (pEDA), and electronic-based (Shannon Aromaticity;
(SA)) indices. All indices are well correlated to each other and to some local (atomic charges) and global (binding-energy)
properties, with one exception—HOMA. The same regularity is observed for non-equilibrium complexes. 相似文献
94.
The oximation of a variety of carbonyl compounds was efficiently carried out with DOWEX(R)50WX4/NH2OH·HCl system. The reactions were performed in ethanol to give Z‐aldoximation isomers of aldehydes and E‐oximaton of acetophenone derivatives in a perfect selectively. The oximation of compounds with two carbonyl groups was carried out selectively on one carbonyl moiety. Also, the oximation of aldehydes over ketones has been accomplished successfully by this system. 相似文献
95.
Graphene/ZnO hybrid was used, for the first time, to fabricate a highly selective and sensitive graphene based gas sensor by a combination of electromechanical and electrochemical characteristics of the graphene. ZnO nanowires in our fabricated sensor have two important roles: as the reductant of graphene oxide to obtain graphene and as an efficient electromechanical actuator due to their piezoelectric properties. To investigate the operation of the fabricated sensor as a gas sensor, a selected set of chemical vapors were introduced to the structure. It was found that chemical vapors change the resonance frequency of the graphene/ZnO structure, as well as the electrical resistivity of the sensor. The observed variation of the mechanical and electrical characteristics of the graphene/ZnO in response to gas exposure entitles the graphene/ZnO based sensor as a highly selective/sensitive device for gas sensing applications with distinctive signatures for different gas species. 相似文献
96.
We prove versions of results of Foxby and Holm about modules of finite (Gorenstein) injective dimension and finite (Gorenstein)
projective dimension with respect to a semidualizing module. We also verify special cases of a question of Takahashi and White.
This research was conducted while S.S.-W. visited the IPM in Tehran during July 2008. The research of S.Y. was supported in
part by a grant from the IPM (No. 87130211). 相似文献
97.
In pharmaceutical industry, many drugs exhibit poor solubility in biological fluid. Solubility of drugs affects on the rate of dissolution and bioavailability in biological fluids. The bioavailability of drugs can be enhanced by decreasing the drug particle size. In this study, sulindac was micronized via rapid expansion of supercritical solution (RESS) where CO2 was used as a solvent. The experiments were conducted to investigate the effect of the extraction pressure and temperature (140–230 bar and 40–60 °C), collection distance (1–10 cm), effective nozzle diameter (450–1700 μm) and nozzle length (2–15 mm) on the size and morphology of the sulindac particles. The size and morphology of the precipitated particles were monitored by scanning electron microscopy (SEM). The particle size of intact sulindac particles was about 33.03 μm, while the average particle size of the micronized sulindac particles was between 0.76 and 8.02 μm based on different experimental conditions. Additionally, the different morphology of the micronized particles was observed like needle, rectangular, quasi spherical and irregular form while the morphology of the intact particles of sulindac was rectangular and irregular. 相似文献
98.
Asadollah Boshra Siamak Jadidi Maryam Goudarzi Samaneh Niroumand Maryam Mohammadi 《Journal of Cluster Science》2012,23(2):297-310
Endohedral derivatives of B16N16 nanocage (M@B16N16, M?=?Li+, Na+, K+, Mg2+, Ne, O2?, S2?, F?, Cl?) and its iso-electronic fullerne M@C32 have been employed to investigate the relation between the trapped atom/ion and electrophilicity of the B16N16 and C32 nanocages. The electrophilicity index, ??, of these endohedral nanocages has been evaluated from the ionization potential and the electron affinity computed by vertical ionization/affinity at the B3LYP/6-311++G(df,pd) level. Obtained results illustrate that the nature of trapped atom/ion affects HOMO-LUMO band gap, global electrophilicity indices and reactivity of B16N16 and C32 nanocages. Encapsulation B16N16 with different atom/ions may be a possible method for modifying HOMO-LUMO energy gap, electrophilicity and so chemical characteristics of and C32 nanocages. 相似文献
99.
We propose an all-optical switching scheme based on Raman gain in a silicon nanowaveguide suitable for multichannel optical communication. Raman gain is used for amplification of a control pulse with a higher wavelength, which depletes the tuned channel signal. Separation between control and signal pulses should be equal to the Raman shift in silicon. By employing a 3 mm channel nanowaveguide, we demonstrate a channel attenuation of about 12 dB, while the suppression ratios for the first and second neighboring channels are about 1.6 dB and 1 dB, respectively. This scheme can be used as an all-optical switch in dense wavelength division multiplexing networks. Moreover, we demonstrate that the depleted channel can be retrieved by a control pulse with lower wavelength in which the pulse amplifies the channel in contrast to the prior situation. 相似文献
100.
Electron acceleration in the inverse free electron laser (IFEL) with a helical wiggler in the presence of ion-channel guiding and axial magnetic field is investigated in this article. The effects of tapering wiggler amplitude and axial magnetic field are calculated for the electron acceleration. In free electron lasers, electron beams lose energy through radiation while in IFEL electron beams gain energy from the laser. The equation of electron motion and the equation of energy exchange between a single electron and electromagnetic waves are derived and then solved numerically using the fourth order Runge-Kutta method. The tapering effects of a wiggler magnetic field on electron acceleration are investigated and the results show that the electron acceleration increases in the case of a tapered wiggler magnetic field with a proper taper constant. 相似文献