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71.
A quasi-reversible queue can be associated with certain type of transactions of a Markov chain. It is shown that if Markov chains are coupled in a certain way, then to the resulting chain be associated a queuing network which is itself quasi-reversible and the stationary distribution of the chain takes the product form. The product form for mixed networks is derived from the result for open networks. 相似文献
72.
Shirude PS Ying L Balasubramanian S 《Chemical communications (Cambridge, England)》2008,(17):2007-2009
Single molecule fluorescence spectroscopy has been employed to resolve the conformational heterogeneity, hybridization kinetics and study mutational effects on the c-MYC promoter G-quadruplex. 相似文献
73.
Waller ZA Shirude PS Rodriguez R Balasubramanian S 《Chemical communications (Cambridge, England)》2008,(12):1467-1469
The triarylpyridines are potent G-quadruplex ligands that are highly discriminating against duplex DNA and show promising selectivity between intramolecular quadruplexes. 相似文献
74.
Pravin R. Likhar M. S. Subhas Moumita Roy Sarabindu Roy M. Lakshmi Kantam 《Helvetica chimica acta》2008,91(2):259-264
Pd/C is used as an efficient catalyst for the copper‐free Sonogashira coupling of acid chlorides and terminal alkynes to afford ynones in high yields (Tables 1 and 3). Cyclization of (2‐methoxyaryl)‐substituted ynones induced by I2/ammonium cerium(IV) nitrate (CAN) at room temperature gave 3‐iodochromenones (=3‐iodo‐4H‐1‐benzopyran‐4‐ones) in excellent yield (Table 4). 相似文献
75.
76.
This paper examines dynamical behavior of a nonlinear oscillator which models a quarter-car forced by the road profile. The effect of multiple time delays is studied in detail. The focus is on the influence of delay in the system. This naturally gives rise to a delay differential equation (DDE) model of the system. The domain where the control is efficient in reducing the amplitude of vibration is found by the harmonic balance method. Technical stability within definite time and asymptotic stability is derived for selected gain control parameters. The control gain parameters are chosen according to technical and asymptotic stability. The energy analysis is a combination of Lyapunov’s function and the averaging technique, and is used to analyze the Hopf bifurcation. 相似文献
77.
V. Surendra Babu Damerla Chiranjeevi Tulluri Dr. Rambabu Gundla Lava Naviri Prof. Uma Adepally Pravin S. Iyer Prof. Y. L. N. Murthy Nampally Prabhakar Dr. Subhabrata Sen 《化学:亚洲杂志》2012,7(10):2351-2360
Herein, we report a diversity‐oriented‐synthesis (DOS) approach for the synthesis of biologically relevant molecular scaffolds. Our methodology enables the facile synthesis of fused N‐heterocycles, spirooxoindolones, tetrahydroquinolines, and fused N‐heterocycles. The two‐step sequence starts with a chiral‐bicyclic‐lactam‐directed enolate‐addition/substitution step. This step is followed by a ring‐closure onto the built‐in scaffold electrophile, thereby leading to stereoselective carbocycle‐ and spirocycle‐formation. We used in silico tools to calibrate our compounds with respect to chemical diversity and selected drug‐like properties. We evaluated the biological significance of our scaffolds by screening them in two cancer cell‐lines. In summary, our DOS methodology affords new, diverse scaffolds, thereby resulting in compounds that may have significance in medicinal chemistry. 相似文献
78.
We make optical vortices of different topological charge and diffract them through a quadratic phase mask using the same spatial light modulator. This phase mask shows the diffraction in which the positive diffracted order has different dynamics than the negative diffracted order. The diffraction pattern and its orientation depend on the charge of the vortex as well as its sign. The experimental results are verified with exact analytical results. 相似文献
79.
Pravin Kubade 《Composite Interfaces》2017,24(5):469-487
Halloysite nanotubes (HNTs) have been successfully modified using polyethyleneimine (PEI). HNTs and PEI-modified HNTs-filled 80/20 (wt/wt) polypropylene (PP)/acrylonitrile butadiene styrene (ABS) blends and its nanocomposites in the presence of dual compatibilizer have been prepared by melt mixing technique. The refinement in matrix–droplet morphology, selective localization of PEI-modified HNTs, increase in crystallinity of PP phase, formation of β-form of PP crystals and improved dispersion of PEI-modified HNTs in PP phase has resulted in a remarkable improvement in tensile modulus, impact strength and thermal stability of PEI-modified HNTs-filled 80/20 (wt/wt) PP/ABS blends in presence of dual compatibilizer. The increase in tensile modulus, tensile strength and impact strength for PEI-modified HNTs-filled 80/20 (wt/wt) PP/ABS blends in presence of dual compatibilizer are 28.8, 26.6 and 38.5%, respectively. 相似文献
80.
A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction of acetyl acetone 1, phenyl isothiocynate 2 and 2-chloromethyl derivatives 3a–3c in the presence of potassium carbonate afforded the target compounds, namely ethyl2-(4-acetyl-3-methyl-5-(phenylamino)thiophen-2-yl)-2-oxoacetate derivatives 4a–4e, ethyl 3-(4-acetyl-3-methyl-5-(phenylamino)thiophen-2-yl)-3-oxopropanoate derivatives 4f–4i, di((4-acetyl-3-methyl-5-phenylamino)thiophen-2-yl)ketone derivatives 4j–4n in reasonable overall yields. The synthesized compounds were screened for antimicrobial activity. The detailed synthesis, spectroscopic data and antimicrobial activities of synthesized compounds were reported. 相似文献