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81.
82.
Ramaswamy Murugavel Prof. Subramaniam Kuppuswamy Nayanmoni Gogoi Alexander Steiner Dr. John Bacsa Dr. Ramamoorthy Boomishankar Dr. K. G. Suresh Prof. 《化学:亚洲杂志》2009,4(1):143-153
Tetranuclear manganese(II) phosphates [Mn(dipp)(bpy)]4?4 H2O ( 1 ) and [Mn4(dmpp)2(dmppH)4(bpy)4(H2O)2]?H2O ( 2 ) have been prepared from Mn(OAc)2?4 H2O and 2,6‐diisopropylphenyl phosphate (dippH2) or 2,6‐dimethylphenyl phosphate (dmppH2) in the presence of 2,2′‐bipyridine (bpy). In contrast, the reaction between [Mn(bpy)2(OAc)(ClO4)]?H2O and dippH2 affords [Mn(bpy)2(dippH)]2?2 ClO4?2 CH3OH ( 3 ). The reactions of Mn(OAc)2?4 H2O, dippH2, and pyridine (py) or 3,5‐dimethylpyrazole (dmpz) in CH3CN under reflux afford hexanuclear complexes [Mn6(dipp)6(py)8]?2CH3CN ( 4 ) and [Mn6(dipp)6(dmpz)6(AcOH)2]?2 H2O ( 5 ), respectively. Although compounds 1 and 2 are tetrameric, the former is a closed cubane‐like structure resembling the D4R secondary building unit of zeolites, whereas the latter exists in a staircase structure with fused Mn2O4P2 rings. The core structure of 3 contains a Mn2O4P2 eight‐membered ring that resembles the S4R building block of zeolites. Single‐crystal X‐ray diffraction studies reveal that compounds 4 and 5 have a similar core structure and differ from each other by the neutral ligands coordinated to manganese ions. All six phosphate ligands exist in a doubly deprotonated [(RO)PO32?] form and exhibit two types of binding modes [5.222] and [3.111]. An interesting feature of compounds 1 – 5 is that although they are oligonuclear complexes, there is an absence of oxido bridges. The magnetic properties of compounds 1 – 5 have been investigated in the temperature range 5–298 K, and it was found that all the compounds obey the Curie law. 相似文献
83.
siRNA. A guide for RNA silencing 总被引:19,自引:0,他引:19
RNAi is routinely used to eliminate gene activity for experimental purposes. However, the precise molecular mechanism of RNAi is unknown. Recent papers partially illuminate this mechanism in human cells, advancing the potential application of RNAi toward the treatment of human disease. 相似文献
84.
Ramaswamy Murugavel Mayank Pratap Singh M. Nethaji 《Journal of chemical crystallography》2012,42(1):12-17
Abstract
Condensation reaction involving substituted aminobenzoic acids (2-aminobenzoic acid and 4-aminobenzoic acid) and acetylacetone results in the formation of ketoimines [CH3C(= O)CH2C(CH3)(= NAr)] (Ar = C6H4COOH-4; 1 and C6H4COOH-2 2). Compounds 1 and 2 have been characterized by spectroscopic techniques and by single crystal X-ray diffraction studies. The absorption, emission and life-time measurement studies have also been performed for the new compounds. While compound 1 forms a linear chain type of aggregation though intermolecular hydrogen bonding, compound 2 forms a discrete dimer in the solid state. 相似文献85.
Solving Large Airline Crew Scheduling Problems: Random Pairing Generation and Strong Branching 总被引:1,自引:0,他引:1
Diego Klabjan Ellis L. Johnson George L. Nemhauser Eric Gelman Srini Ramaswamy 《Computational Optimization and Applications》2001,20(1):73-91
The airline crew scheduling problem is the problem of assigning crew itineraries to flights. We develop a new approach for solving the problem that is based on enumerating hundreds of millions random pairings. The linear programming relaxation is solved first and then millions of columns with best reduced cost are selected for the integer program. The number of columns is further reduced by a linear programming based heuristic. Finally an integer solution is obtained with a commercial integer programming solver. The branching rule of the solver is enhanced with a combination of strong branching and a specialized branching rule. The algorithm produces solutions that are significantly better than ones found by current practice. 相似文献
86.
Time-dependent correlation functions of the conformations of a single gaussian polymer chain immersed in a solvent are calculated renormalization-group theoretically. As a byproduct is is confirmed that to order ? (=4-d, d being the spatial dimensionality) the translational diffusion constant obtained fully dynamically (i.e. by the Green-Kubo formalism) is identical to that obtained by the Kirkwood theory (or the Kirkwood-Riseman formalism) even with the self-avoiding interaction. 相似文献
87.
David Reynolds Anthony J. Mulholland Jagannathan Gomatam 《Journal of mathematical chemistry》1997,22(1):25-37
We present a new class of techniques for the solution of the chemical and phase equilibria problem for reacting species in a closed system. The minimisation of the Gibbs free energy for all the species in the system is conducted using the technique of simulated annealing (SA). The SA objective function incorporates non‐ideal equations of state. This new approach is demonstrably able to solve multi‐species and multi‐phase LTCE problems in ideal‐gas solutions, ideal solutions and mixtures of ideal and non‐ideal solutions. 相似文献
88.
Sridhar Jagannathan 《国际流体数值方法杂志》1992,14(7):793-815
In the simulation of non-linear free surface flows in a finite domain a major concern is with the radiation condition to be applied at the ‘open’ boundary. No general theoretical radiation conditions are known to exist. In this paper a new open boundary condition is formulated based on energy flux equalization between the non-linear inner domain and a linear outer domain. The non-linear flow in the inner domain is solved numerically using a semi-Lagrangian procedure. The energy flux arriving at the open boundary is removed using a new open boundary condition which acts as a linear wave absorber. For the cases studied the performance of this boundary condition is found to be quite good. 相似文献
89.
A new version of a numerical algorithm for the Lagrangian treatment of incompressible fluid flows with free surfaces is developed. The novel features of the present method are the adoptions of the Lagrangian finite element method and the velocity correction technique. The use of the velocity correction approach makes the computational scheme extremely simple in algorithmic structure. Hence, the present method is particularly attractive for large-scale problems. The techniques discussed here are applied to some two-dimensional sloshing problems, which may indicate the versatility and effectiveness of the present method. 相似文献
90.
Veda Ramaswamy Vimal Kothiyal Indra D. Singh Rajamani Krishna 《Fresenius' Journal of Analytical Chemistry》1988,332(4):358-361
Summary A simple and fast column chromatographic procedure for the separation of vacuum residues into saturates, mono-, di-, polyaromatics and polars has been standardized using silica-alumina-bauxite adsorbents and gradient elution with n-pentane, benzene, and methanol. The cut points have been monitored employing ultraviolet and infrared spectroscopy. The method is applicable for preparative separation of short residues from processed products.
Rasche Trennung der Kohlenwasserstofftypen von Vakuum-RückstÄnden相似文献