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排序方式: 共有426条查询结果,搜索用时 343 毫秒
51.
Esmaeil Shahriari W. Mahmood Mat Yunus Kazem Naghavi Z.A. Talib 《Optics Communications》2010,283(9):1929-1932
Nonlinear properties of Au nano-fluid prepared by γ-radiation method at different concentrations were investigated. Measurements of nonlinear refractive index and nonlinear absorption coefficient were carried out using a single beam Z-scan technique. A green CW laser beam operated at 532 nm was used as excitation source. The Au nano-fluid shows a good third order nonlinear response. The sign of the nonlinear refractive index is found to be negative and the magnitude is in the order of 10−7 cm2/W. This nonlinear effect increases as the concentration increases from 3.119 × 10−4 to 2.354 × 10−3 M which correspond to particle sizes of 4.0-30.5 nm, respectively. A good linear relationship was obtained between nonlinear refractive index and concentration. However the relationship between nonlinear refractive index and particle size was nonlinear behavior. 相似文献
52.
Hunter M Backman V Popescu G Kalashnikov M Boone CW Wax A Gopal V Badizadegan K Stoner GD Feld MS 《Physical review letters》2006,97(13):138102
Light scattered from biological tissues can exhibit an inverse power law spectral component. We develop a model based on the Born approximation and von Karman (self-affine) spatial correlation of submicron tissue refractive index to account for this. The model is applied to light scattering spectra obtained from excised esophagi of normal and carcinogen-treated rats. Power law exponents used to fit dysplastic tissue site spectra are significantly smaller than those from normal sites, indicating that changes in tissue self-affinity can serve as a potential biomarker for precancer. 相似文献
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54.
The recent studies carried out on the binding of small molecule to deoxyribonucleic acids suggested that the intercalation of a tricyclic heteroaromatic molecule, thionine, with natural DNAs provided thermal stabilization to the DNA complex. In the present study, we reported theoretical analysis of thionine binding with natural DNAs of varying base composition by using an amended Zimm and Bragg theory, to explain the melting behaviour and heat capacity of DNAs with and without thionine binding. We used experimental models of Paul et al. for implementing this study (Paul et al., 2010). The sharpness of transition has been examined in terms of half width and sensitivity parameter (ΔH/σ). The results of theoretical analysis concluded that the various parameters such as heat capacity curve, transition profile, half widths and sharpness of the transition are in good agreement with the experimental measurements for binding of thionine determined through DSC. The theoretical analysis proposed in this study, therefore, may be useful to understand interaction of small molecules with deoxyribonucleic acids. This approach may also be applied to design DNA binding therapeutic molecules and in the process of drug formulation and development. 相似文献
55.
The nature (time variation) of response magnetizations m(wt) of the kinetic cylindrical Ising nanotube in the presence of a periodically varying external magnetic field h(wt) is studied by employing the effective-field theory (EFT) with correlations as well as the Glauber-type stochastic dynamics. We have determined the time variations of m(wt) and h(wt) for various temperatures, and investigated the dynamic magnetic hysteresis behavior. Temperature dependence of the dynamic magnetizations, hysteresis loop areas and correlations are investigated in order to characterize the nature (first- or second-order) of the dynamic transitions as well as to obtain the dynamic phase transition temperatures. We also present the dynamic phase diagrams in the three different planes and compare the results of the equilibrium and nonequilibrium states. The phase diagrams exhibit dynamic tricritical, isolated critical, multicritical and triple points. The results are in good agreement with some experimental and theoretical results. 相似文献
56.
With the rapid development in computer technologies, mathematical programming-based technique to solve scheduling problems is significantly receiving attention from researchers. Although, it is not efficient solution method due to the NP-hard structure of these problems, mathematical programming formulation is the first step to develop an effective heuristic. Numerous comparative studies for variety scheduling problems have appeared over the years. But in our search in literature there is not an entirely review for mathematical formulations of flexible job shop scheduling problems (FJSP). In this paper, four the most widely used formulations of the FJSP are compiled from literature and a time-indexed model for FJSP is proposed. These formulations are evaluated under three categories that are distinguished by the type of binary variable that they rely on for using of sequencing operations on machines. All five formulations compared and results are presented. 相似文献
57.
Yunus Taskesenligil Ferruh Lafzi Haydar Kilic Nurullah Saracoglu 《Journal of heterocyclic chemistry》2019,56(12):3289-3296
Pd(II)‐catalyzed C‐H arylations of 5‐aminoindole using iodobenzenes as aryl source was studied. Despite pivalamide directing group at 5‐position of the indole, the direct C2‐arylation of the indole observed in high yields and with high regioselectivity. 相似文献
58.
59.
Nazoktabar Mohsen Arshtabar Kamran Mohammadkhani Hassan 《Journal of Thermal Analysis and Calorimetry》2020,139(4):2519-2526
Journal of Thermal Analysis and Calorimetry - Nowadays, modern engines control a wide range of parameters in order to meet desired functions and standards. Measurement of mechanical systems has... 相似文献
60.
Plasma Chemistry and Plasma Processing - In this study, thin films of poly(cyclohexyl methacrylate) (PCHMA) were deposited on silicon wafer using PECVD technique, in which the plasma power is... 相似文献