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排序方式: 共有681条查询结果,搜索用时 9 毫秒
671.
An S-arithmetic Khintchine-type theorem for products of non-degenerate analytic p-adic manifolds is proved for the convergence case. In the p-adic case the divergence part is also obtained. 相似文献
672.
G. Rezaei Behbehani M. Mirzaie M. Mehreshtiag L. Barzegar A. A. Saboury S. Mohammadi Gorgi 《Journal of solution chemistry》2012,41(4):581-588
The binding properties and structural changes of mushroom tyrosinase enzyme, MT, due to its interactions with phenyl dithiocarbamate (I) and p-phenylene-bis dithiocarbamate (II), were investigated at 27 and 37 °C in phosphate buffer (10?mmol?L?1) at pH = 6.8 by isothermal titration calorimetric (ITC). The extended solvation model was used to calculate the solvation parameters, which were attributed to the stability of this enzyme. Thermodynamic analysis indicated that the predominant mode of interaction was hydrophobic in the binding of compound I to MT, while the binding of II to MT essentially depends on electrostatic interactions. It seems that II is a more potent MT inhibitor due to its two charged head groups that are able to chelate copper ions in the active enzyme site. It was concluded that MT has two distinct sites for p-phenylene-bis and phenyl dithiocarbamate. 相似文献
673.
Javad Azizian Ali A. Mohammadi Ebrahim Soleimani Ali R. Karimi Mohammad R. Mohammadizadeh 《Journal of heterocyclic chemistry》2006,43(1):187-190
674.
A polydimethylsiloxane (PDMS) membrane was synthesized and permeation behavior of ternary gas mixtures including C3H8, CH4 and H2 through it was studied as a function of operating parameters. Mixed gas permeability values were also compared with pure gas data as well as literature to validate experimental results. The aim was to predict separation factor (SF) of C3H8 as a function of feed temperature, pressure, flow rate and C3H8 concentration with the aid of artificial neural network (ANN) technique. Multilayer perceptron (MLP), which is the most common type of feedforward neural network (FFNN), was used for prediction. The Levenberg–Marquardt training method was initially employed to train the net. Then, optimum numbers of hidden layers and nodes in each layer were determined. The selected structure (4:4:5:1) was finally used to predict SF of C3H8 for different inputs in the domain of training data. The modeling results showed that there is an excellent agreement between the experimental data and the predicted values, with mean absolute errors of less than 1%. Both modeling and experimental results confirmed that increasing feed temperature, feed pressure and C3H8 concentration in feed debilitates separation performance; however, SF increases with increasing feed flow rate. As a result, ANN can be recommended for the modeling of mixed gas transport through dense membranes such as PDMS. 相似文献
675.
The Optimization utilization of raw material and components is one of the main challenges in production and project management success. Executives usually face with waste and shortage of raw material which cause delay and cost, however the material and required components are usually provided more than needed. Therefore planning to provide these components from existing spools of material is one of these challenges especially when the number of the needed material pieces and the existing spools are high. For instance, in power plant projects cables are usually provided in form of spools which later cut down to required pieces in the project location. Extraction of each needed piece of cable from specific existing spool is a decision to be made. In this paper, a heuristic method based on integrating Integer Goal Programming and Taguchi Method is suggested to optimize cutting down process of these materials. 相似文献
676.
After a quick review of the Lane-Emden equation and its properties, a composite of two different polytropes is introduced
and some of the consequences are explored. The results are used to build a nonlinear electromagnetism with non-singular, solitonic
solutions as charged particles. 相似文献
677.
Sandaroos R Damavandi S Salimi M Mohammadi A Karimian A Hasanpour M 《Molecular diversity》2012,16(2):269-277
A new approach for the preparation of new 9-(alkyl or aryl)acenaphtho[1,2-b]furan-8-(alky or aryl) amine derivatives has been reported by the catalyst-free one-pot cyclocondensation of (acenaphthylen-1-yloxy)trimethylsilane, alkyl and aryl aldehydes, and aryl and alky isocyanides in refluxing DMF. 相似文献
678.
MOHAMMADI Behrouz MOHAMMADI Jalalb 《中国化学》2007,25(3):284-288
By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^++ Mo(Ⅵ)+nitrilotriacetic acid and H^+ + nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum(Ⅵ) forms a mononuclear 1 : 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^+] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft's parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation. 相似文献
679.
F. Kheirandish S. J. Akhtarshenas H. Mohammadi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(1):129-140
Entanglement dynamics of an open two-qubit anisotropic
XY Heisenberg system is investigated in the presence of an
inhomogeneous magnetic field and spin-orbit interaction. We
suppose that each qubit interacts with a separate thermal
reservoir which is held in its own temperature. The asymptotical
and the dynamical behavior of entanglement are analyzed. To
distinguish between entanglement induced by the environment and
entanglement due to the presence of inter-qubit interaction, the
effects of spin-orbit parameter D and temperature difference
parameter ΔT on the entanglement of the system have been
investigated. We show that for a fixed set of the system
parameters, entanglement can be produced just by adjusting the
temperature difference between the reservoirs. The size of this
entanglement, which is induced by temperature difference of
reservoirs, increases as the spin-orbit parameter D increases.
Also we find that, this environment induced entanglement can be
improved if the qubit influenced by the weaker magnetic field is
in contact with the hotter reservoir, i.e. indirect geometry of
connection. In this case, the amount of asymptotic entanglement
increases as D increases. Regardless of the geometry of
connection, increasing D causes the appearance of entanglement
in the larger regions of TM-ΔT plane, therefore
entanglement can exist in higher temperatures and temperature
differences. Furthermore, increasing D enhances the amount of
entanglement in these regions. We also show that the state of the
system can be found in the maximally entangled state for the case
of zero temperature reservoirs and large amount of the spin-orbit
parameter. 相似文献
680.
M. Mohammadi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(2):255-260
The temporal evolution of both the atomic population inversion of an effective two-level atom and the cross correlation between
the two modes in two-photon Jaynes-Cummings model in the presence of a classical homogeneous gravitational field are investigated.
To analyse the dynamical evolution of the atom-radiation system a quantum treatment of the internal and external dynamics
of the atom is presented based on an alternative su(2) dynamical algebraic structure. By solving the Schr?dinger equation
in the interaction picture, the evolving state of the system is found by which the influence of the gravitational field on
the dynamical behavior of both the atomic population inversion of an effective two-level atom and the cross correlation between
the two modes of the radiation field are explored. Assuming that initially the radiation field is prepared in the coherent
state for each mode and an effective two-level atom is in a coherent superposition of the excited and ground states, the influence
of gravity on both the atomic population inversion of an effective two-level atom and the cross correlation between the two
modes of the radiation field are studied. 相似文献