Simulation model for shapiro time delay and light deflection experiments

The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this model that does not use the general relativistic equations. The computed values presented in this paper compare well with recent levels of accuracy of their respective experimental results.     

Schur complement preconditioners for anisotropic problems

We present two new variants of Schur complement domain decompositionpreconditioners suitable for 2D anisotropic problems. Thesevariants are based on adaptations of the probing idea, describedby Chan et al (1992 Fifth Int. Symp. on Domain DecompositionMethods for Partial Differential Equations, Philadelphia: SIAM,pp 236-249), used in conjunction with a coarse grid approximationas introduced by Bramble et al (1986 Math. Comput. 47, 103-134).The new methods are specifically designed for situations wherethe coupling between neighbouring interfaces is stronger thanthe coupling within an interface. Taking into account this strongcoupling, one variant uses a multicolour probing technique toavoid distortion in the probe approximations that appear whenusing the method proposed by Chan et al. The second techniqueuses additional probe matrices to approximate not only the couplingwithin the interfaces but also the coupling between interfacepoints across the subdomains. This latter procedure looks somewhatlike an alternating line relaxation method for anisotropic problems,see Brandt (1977 Math. Comput.. 31, 333-390). To assess therelevance of the new preconditioners, we compare their numericalbehaviour with well known robust preconditioners such as thebalanced Neumann-Neumann method proposed by Mandel (1993 Commun.Numer. Methods Eng.. 9, 233-241).     

Simulation model for anomalous precession of the perihelion of mercury's orbit

The ‘anomalous perihelion precession’ of Mercury, announced by Le Verrier in 1859, was a highly controversial topic for more than half a century and invoked many alternative theories until 1916, when Einstein presented his theory of general relativity as an alternative theory of gravitation and showed perihelion precession to be one of its potential manifestations. As perihelion precession was a directly derived result of the full General Theory and not just the Equivalence Principle, Einstein viewed it as the most critical test of his theory. This paper presents the computed value of the anomalous perihelion precession of Mercury's orbit using a new relativistic simulation model that employs a simple transformation factor for mass and time, proposed in an earlier paper. This computed value compares well with the prediction of general relativity and is, also, in complete agreement with the observed value within its range of uncertainty. No general relativistic equations have been used for computing the results presented in this paper.     

评《马氏决策过程》

（《马氏决策过程》,侯振挺、郭先平著,长沙,湖南科技出版社,1997,中文版,386页,定价：28元）马尔可夫决策过程是概率论的运筹学的理论研究和实际应用中极其重要的领域之一．随着中国和国际上对马尔可夫决策过程（MarkovDecisionProcesses,简记为MDP）研究的新进展,许     

Syntheses, spectroscopy, and redox chemistry of encapsulated oxo-Mo(V) centers: implications for pyranopterin-containing molybdoenzymes

Coordination by at least four sulfur donors to an embedded molybdenum center has been found to be a common feature in the crystal structures of many mononuclear molybdenum enzymes. In an effort to model embedded molybdenum centers, we have synthesized dendritic thiolate ligands and their oxo-molybdenum complexes containing a [Mo(V)OS(4)](-) core. These compounds have been isolated in pure form as blue solids or gummy materials, and the molecular nature of these compounds has been confirmed by electrospray ionization mass spectrometry and infrared, electron paramagnetic resonance, and UV-vis spectroscopies. The dendritic complexes exhibit little variation in their broad S --> Mo charge transfer band (lambda(max) approximately 600 nm; epsilon approximately 6000 M(-)(1) cm(-)(1)), Mo=O vibration energy (941-943 cm(-)(1)), and EPR g-values (g( parallel ) approximately 2.02; g( perpendicular ) approximately 1.98; g(av) approximately 1.99). The spectroscopic data confirm the integrity of the square pyramidal [Mo(V)OS(4)](-) core with little geometric distortions, suggesting that the electronic structure at the metal center is not perturbed by the ligand architecture. The electronic structure of these complexes, calculated by the density functional theory, demonstrates a similar composition of the HOMO. In complexes 6 and 7a, the energy of the HOMO orbital might be modulated by the difference in the electronic structure of the ligands. The Mo(V/IV) reduction potentials vary as a function of the dielectric constant and the donor number of the solvent. The kinetics of the reduction is influenced by the reorganization of the geometry and the encapsulating effect. We suggest that protein structure imposed microenvironments may control the dielectric properties and hence the redox properties of the metal center in many metallobiomolecules.     

Design, syntheses, and characterization of dioxo-molybdenum(VI) complexes with thiolate ligands: effects of intraligand NH...S hydrogen bonding

Presence of the hydrogen bonding near a metal center can influence the properties of the complex. Here, we describe changes in redox and spectral properties in discrete dioxo-molybdenum centers coordinated by a single thiolato ligand that can support an intra-ligand hydrogen bond. We have utilized thiophenolato ligands that can harbor hydrogen bonding between the thiophenolato sulfur with an amide functionality creating either a five- or a six-membered ring. Methylation of the amide functionality removes the NH...S hydrogen bonding thus providing a basis for understanding the effect of hydrogen bonding. These thiophenolato ligands have been used in synthesizing dioxo-MoVI complexes of type Tp*MoO2(S-o-RC6H4), where R=CONHMe (), CONMe2 (), NHCOMe (), and N(Me)COMe (). The complexes have been characterized by NMR, infrared, and UV-visible spectroscopy. Spectroscopic data clearly indicate the presence of hydrogen bonding in both and , and stronger in , where hydrogen bonding stabilizes a five-membered ring. All complexes exhibit a Mo(VI)/Mo(V) redox couple and redox potentials are modulated by the nature of H-bonding. Compound with the electron-releasing N(Me)COMe group has the highest reduction potential and is more difficult to reduce.     

Simultaneous quantitation of IC87114, roflumilast and its active metabolite roflumilast N‐oxide in plasma by LC‐MS/MS: application for a pharmacokinetic study

A sensitive and reliable high‐performance liquid chromatography–mass spectrometry (LC–MS/MS) was developed and validated for simultaneous quantification IC87114, roflumilast (RFM), and its active metabolite roflumilast N‐oxide (RFN) using tolbutamide as an internal standard. The analytes were extracted by using liquid–liquid extraction and separated on a reverse phase C₁₈ column (50 mm × 3 mm i.d., 4.6 µ) using methanol: 2 mM ammonium acetate buffer, pH 4.0 as mobile phase at a flow rate 1 mL/min in gradient mode. Selective reaction monitoring was performed using the transitions m/z 398.3 > 145.9, 403.1 >186.9, 419.1 > 187.0 and 271.1 > 155.0 to quantify quantification IC87114, RFM, RFN and tolbutamide, respectively. The method was validated over the concentration range of 0.1–60 ng.mL^?1 for RFM and RFN and 6 to 2980 ng.mL^?1 for IC87114. Intra‐ and inter‐day accuracy and precision of validated method were within the acceptable limits of <15% at all concentrations. Coefficients of correlation (r²) for the calibration curves were >0.99 for all analytes. The quantitation method was successfully applied for simultaneous estimation of IC87114, RFM and RFN in a pharmacokinetic drug–drug interaction study in Wistar rats. Copyright © 2012 John Wiley & Sons, Ltd.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Tri‐tert‐butyl 3‐oxo‐4‐oxa‐1,8,11‐triazaspiro[5.6]dodecane‐1,8,11‐triacetate

The title compound, C₂₆H₄₅N₃O₈, is a bicyclic molecule; the seven‐membered diazepane ring has a twisted‐chair conformation and the six‐membered morpholine ring has a boat conformation.