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排序方式: 共有187条查询结果,搜索用时 296 毫秒
111.
Wang Zhen Khalaf Abdul Jalil M. Tian Huaigu Alsaedi Ahmed Hayat Tasawar 《The European physical journal. Special topics》2020,229(6-7):1109-1116
The European Physical Journal Special Topics - Although chaotic flows with special properties in their equilibria have been investigated widely, such an effort about chaotic maps has been... 相似文献
112.
Reem Shah Turki M. Habeebullah Fawaz Saad Ismail Althagafi Aisha Y. Al-dawood Amerah M. Al-Solimy Zehba A. Al-Ahmed Fatimah Al-Zahrani Thoraya A. Farghaly Nashwa El-Metwaly 《应用有机金属化学》2020,34(10):e5886
Five new nitrogen-rich ligands (thioanhydrides) were synthesized and fully characterized. Then, their corresponding Co(II) complexes were prepared and also elucidated by analytical and spectral conformational techniques. First of all, the mono-negative tri-dentate mode was proposed with all derivatives towards mono-nuclear central atom. According to ligand field transitions and magnetic susceptibility values, the square-planar as well as octahedral geometries were the forms suggested. The presence of water molecules was investigated thermally. For conformational implementation under optimal conditions, energy minimization was carried out and fundamental data were obtained and studied. In silico investigation was carried out using the MOE docking approach to predict the inhibition activity for the new compounds. The Co(II)– 3e complex played an excellent inhibitory role. After that and based on preliminary results, in vitro antitumor screening against MCF-7 cell line was conducted for all Co(II) complexes. The results were consistent with that for standard drug (doxorubicin), and the inhibition feature for the complexes was ranked. Through photographic monitoring, outstanding inhibition activity towards breast cancer spreading was recorded for the Co(II)– 3e complex, which coincides well with MOE docking data. 相似文献
113.
Numerical Algorithms - The main aim of this research study is to present a new and efficient numerical method based on the second kind Chebyshev wavelets for solving the general form of distributed... 相似文献
114.
Jahede Tekeykhah Seyed Mohsen Hosseini Gholamali Jalali Jalil Alavi Abbas Esmaili Sari 《声与振动》2019,53(6):263-276
Sound pollution is one of the most important urban problems which
endangers mental and physical health of the residents. This study was aimed to
assess the influence of different tree species, including Fraxinus rotundifolia,
Robinia pseudoacacia, Platanus orientalis, Platycladus orientalis, and Pinus
eldarica, in reducing noise pollution in the Abidar Forest Park. A further objective was to identify the contaminated areas of Sanandaj city and to propose suitable noise absorbent tree species in consistent conditions. For each tree stands
the noise measurements were performed during intervals at frequencies of 250,
500 and 1000 Hz, besides an open area with the same topography. With regards
to the second purpose, a total of 50 stations with residential, commercial, residentialcommercial, and green space applications were selected across the city. Equivalent
Continuous Sound Pressure Level (Leq) was determined in five replicates for 30
min. The measurements were performed under stable weather conditions and low
wind velocity at 17:00 (traffic peak) in summer and fall. All of the Leq values were
above the threshold noise level. The highest noise reduction was recorded in summer
(i.e., green season); Platanus and Platycladus species demonstrated the highest and
lowest noise absorption (31.43 dB and 22.28 dB, respectively). Furthermore, a
meaningful difference was observed between Leq values of commercial, residential,
commercial-residential, and green space urban applications, and the central parts of
the city showed noticeable noise pollution. Taken together, due to being exposed to
higher than the acceptable threshold noise level, the residents of Sanandaj will be
endangered to health problems in the near future; thus consideration should be given
to the noise pollution sources. 相似文献
115.
Nourhene Kamoun Allouche Tarak Ben Nasr Cathy Guasch Najoua Kamoun Turki 《Comptes Rendus Chimie》2010,13(11):1364-1369
Semiconducting copper sulphide (Cu2S) thin films have been deposited on various substrates (SnO2:F/glass, glass) by the simple and economical chemical bath deposition technique. The depositions were carried out during a deposition time of about 32.5 min in the pH range of 9.4 to 11. The synthesized Cu2S thin films were characterized using various techniques without any annealing treatment. X-ray diffraction study shows that Cu2S films exhibit the best crystallinity for pH = 10.2. For this pH value, Auger electron spectroscopy investigations show that Cu2S thin films grown on an SnO2/glass substrate exhibit stochiometric composition with [Cu]/[S] concentrations ratio equal to 2.02. Using the Kelvin method, the work function difference (Фmaterial– Фprobe) for the Cu2S films deposited on SnO2/glass substrates at the optimum pH value was found to be equal to 145 meV. Hall measurements confirm the p-type electrical conductivity of the obtained films. The electrical resistivity was of the order of 3.85 × 10−4 Ω-cm. The transmission and reflection coefficients vary in the range of [35–60] % and [5–15] % respectively, in the visible range, and the band gap energy is about 2.37 eV. 相似文献
116.
Murahashi T Nakashima H Nagai T Mino Y Okuno T Jalil MA Kurosawa H 《Journal of the American Chemical Society》2006,128(13):4377-4388
The reaction of [Pd(2)(CH(3)CN)(6)][BF(4)](2) (1) with 1,3,5-hexatriene, 1,6-diphenyl-1,3,5-hexatriene (DPHT), or 2,2,9,9-tetramethyl-3,5,7-decatriene (DBHT) afforded bi-eta(3)-allyldipalladium complexes 3, 4, or 5. The reaction of 1 and DBHT proceeded in a stereospecific (syn) manner when the reaction was carried out in CD(2)Cl(2) under aerobic conditions, while a mixture of two diastereomers was formed under N(2) atmosphere. The two diastereomers (5-E,Z,E-antifacial and 5-E,E,E-antifacial) formed from DBHT were isolated, and the structure of 5-E,Z,E-antifacial, which was kinetically formed from the reaction of 1 and (E,E,E)-DBHT, was determined by X-ray diffraction analysis. Addition of phosphine ligands (PPh(3) or dppm) to the dinuclear adduct 5-E,Z,E-antifacial or 5-E,E,E-antifacial in acetonitrile resulted in the stereospecific (syn) elimination of [Pd(2)(PPh(3))(2)(CH(3)CN)(4)][BF(4)](2) (2) or [Pd(2)(dppm)(2)(CH(3)CN)(2)][BF(4)](2) (6). During the PPh(3)-induced dinuclear elimination, the phosphine adducts 7 that retain bi-eta(3)-allyldipalladium structure were observed initially. The phosphine adduct generated from 5-E,E,E-antifacial was isolated and structurally characterized by X-ray diffraction analysis. The reaction of 1 and DPHT in CH(2)Cl(2) afforded unique dipalladium sandwich compounds [Pd(2)(mu-eta(3):eta(3)-DPHT)(2)][BF(4)](2) (8). Interconversion between the sandwich complexes and half-sandwich complexes occurred in a stereoretentive manner. The structure of the sandwich complex 8-E,Z,E formed from 4-E,E,E-antifacial and (E,Z,E)-DPHT was determined by X-ray diffraction analysis. Transfer of the dipalladium moiety [Pd(2)(CH(3)CN)(4)](2+) from DPHT ligand of 4-E,E,E-antifacial onto DBHT ligand proceeded in a stereoretentive manner. The observed stereoretentive dinuclear process is featured by the pairwise behavior of two palladium atoms sitting on the triene pi-plane. In the dinuclear elimination, the two Pd atoms that are initially in the divalent state and bound on the opposite faces (antifacial) come to the synfacial positions to form a Pd-Pd bond prior to dissociation. These results represent the unique property of conjugated olefin as the multidentate ligands for metal-metal moieties. 相似文献
117.
A sixth-order numerical scheme is developed for general nonlinear fifth-order two point boundary-value problems. The standard
sextic spline for the solution of fifth order two point boundary-value problems gives only O(h
2) accuracy and leads to non-optimal approximations. In order to derive higher orders of accuracy, high order perturbations
of the problem are generated and applied to construct the numerical algorithm. O(h
6) global error estimates obtained for these problems. The convergence properties of the method is studied. This scheme has
been applied to the system of nonlinear fifth order two-point boundary value problem too. Numerical results are given to illustrate
the efficiency of the proposed method computationally. Results from the numerical experiments, verify the theoretical behavior
of the orders of convergence. 相似文献
118.
We study the emergence of in-phase and anti-phase synchronized rhythms in bursting networks of Hodgkin-Huxley-type neurons connected by inhibitory synapses. We show that when the state of the individual neuron composing the network is close to the transition from bursting into tonic spiking, the appearance of the network’s synchronous rhythms becomes sensitive to small changes in parameters and synaptic coupling strengths. This bursting-spiking transition is associated with codimension-one bifurcations of a saddle-node limit cycle with homoclinic orbits, first described and studied by Leonid Pavlovich Shilnikov. By this paper, we pay tribute to his pioneering results and emphasize their importance for understanding the cooperative behavior of bursting neurons. We describe the burst-duration mechanism of inphase synchronized bursting in a network with strong repulsive connections, induced by weak inhibition. Through the stability analysis, we also reveal the dual property of fast reciprocal inhibition to establish in- and anti-phase synchronized bursting. 相似文献
119.
N.A. Khilo Turki S.M. Al-SaudSoliman H. Al-Khowaiter Muhanna K. Al-MuhannaS.V. Solonevich N.S. KazakA.A. Ryzhevich 《Optics Communications》2012,285(24):4807-4810
As was shown previously, in propagation of a circularly polarized Bessel light beam along the optical axes of a biaxial crystal, there takes place the conversion of the order of Bessel function. In this paper, a new result is presented which is obtained by varying the polarization state of an input beam. Namely, a linearly polarized beam can be transformed into a beam with the radial or azimuthal polarization state. At that the order-transformation also occurs. The switching between radial and azimuthal polarization states of the output beam is performed by the proper switching between two orthogonal linear polarization states of the input beam. The efficiency of polarization conversion is high and can be practically full at an appropriate choice of the cone angle of the input beam or crystal length. 相似文献
120.
The conductance through a mesoscopic system of interacting electrons coupled to two adjacent leads is conventionally derived via the Keldysh nonequilibrium Green’s function technique, in the limit of noninteracting leads [Y. Meir, N.S. Wingreen, Phys. Rev. Lett. 68 (1992) 2512]. We extend the standard formalism to cater for a quantum dot system with Coulombic interactions between the quantum dot and the leads. The general current expression is obtained by considering the equation of motion of the time-ordered Green’s function of the system. The nonequilibrium effects of the interacting leads are then incorporated by determining the contour-ordered Green’s function over the Keldysh loop and applying Langreth’s theorem. The dot–lead interactions significantly increase the height of the Kondo peaks in density of states of the quantum dot. This translates into two Kondo peaks in the spin differential conductance when the magnitude of the spin bias equals that of the Zeeman splitting. There also exists a plateau in the charge differential conductance due to the combined effect of spin bias and the Zeeman splitting. The low-bias conductance plateau with sharp edges is also a characteristic of the Kondo effect. The conductance plateau disappears for the case of asymmetric dot–lead interaction. 相似文献