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1.
R. Chitra Pascal Roussel R. R. Choudhury 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o547-o549
The title complex, 2CH4N2S·C4H6O4, is a host–guest system. The asymmetric unit consists of one complete thiourea molecule and one‐half of a dimethyl oxalate molecule lying on an inversion centre. The host thiourea molecules are connected to form zigzag chains by N—H⋯S hydrogen bonds. The guest dimethyl oxalate molecules provide O‐atom acceptors for N—H⋯O hydrogen bonds, thus interconnecting the chains of thiourea molecules to form completely connected sheets. The reduction in temperature from 300 to 100 K leaves the structure unchanged and still isostructural with that previously determined for the analogous thiourea–diethyl oxalate (2/1) complex. It does, however, induce closer packing of the molecules, general shrinkage of the unit cell and shortening of the hydrogen bonds, these last two to the extent of 1–2%. 相似文献
2.
This paper examines the steady state behaviour of a batch arrival queue with two phases of heterogeneous service along and Bernoulli schedule vacation under multiple vacation policy, where after two successive phases service or first vacation the server may go for further vacations until it finds a new batch of customer in the system. We carry out an extensive stationary analysis of the system, including existence of stationary regime, queue size distribution of idle period process, embedded Markov chain steady state distribution of stationary queue size, busy period distribution along with some system characteristics. 相似文献
3.
Sharmistha Dutta Choudhury 《Journal of luminescence》2007,124(1):33-38
Laser flash photolysis of phenazine (PZ) solution reveals the existence of a stable species with a long lifetime at 380 nm in addition to the usual triplet PZ at 440 nm. The former is suggested to be due to formation of triplet PZ excimer. The triplet excimer also undergoes photoinduced electron transfer with some aromatic amines. The formation of PZ dimer anion radical and amine cation radicals are confirmed by external magnetic field effect studies. Measurement of B1/2, which estimates hyperfine present in the system, also supports this assignment. 相似文献
4.
A holographic image subtraction technique is proposed. The vector nature of light is utilized in introducing a phase difference of π between the two reconstructed object waves. The experimental results are also presented. 相似文献
5.
Dipak Ghosh Madhumita Lahiri Argha Deb Susobhan Das Krishnadas Purkait Biswanath Biswas Jayanta Roy Choudhury Rini Chatterjee Abdul Kayum Jafry 《Zeitschrift fur Physik C Particles and Fields》1996,71(1):243-249
The scaled factorial moments and the multifractal moments have been investigated in differentη-intervals to study the dynamical fluctuation of pions produced in 200 AGeV32S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process. 相似文献
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Methods have been developed to allow applications of membrane introduction mass spectrometry (MIMS) to monitor solution phase components of fermentation broths using electron ionization. The solutions are transported by flow injection analysis (FIA) through a direct insertion membrane probe, fitted with a silicone membrane in the sheet configuration. Analytes of interest pass through the membrane and are ionized by electron implant ionization. The compounds monitored are ammonia, acetic acid, and ethanol, with ammonia being detected as the monochloramine derivative which is generated at pH 10 upon addition of hypochlorite. Quantitation is achieved using external standard solutions. The dynamic range for the quantification of ammonia is 2-8000 ppm, and for ethanol and acetic acid 10-1000 ppm. This method provides rapid detection of analytes of interest, on-line monitoring capabilities, and the advantage of electron ionization. The introduction of samples into the mass spectrometer is achieved readily and automatically, the response time is a few seconds, and there are no memory effects. 相似文献
9.
Gurucharan Mukherjee Sailendra Nath Poddar Kingshuk Choudhury Kamalendu Dey 《Transition Metal Chemistry》1988,13(1):58-63
Summary Iron(III) complexes of a quadridentate N2S2 donor ligand, 1,2-di(o-aminophenylthio)ethane (DAPTE) and its Schiff Base with salicylaldehyde, a hexadentate N2S2O2 donor ligand,viz. 1,2-di(o-salicylaldiminophenylthio)ethane (H2DSALPTE) have been synthesised and characterised.The Schiff base ligand (1 mol) gave a dark green tri-iron(III) [Fe3(DSALPTE)(HDSALPTE)Cl3]Cl2 complex when reacted with anhydrous iron(III) chloride (1 mol). The Mössbauer data of this complex suggest the presence of three iron sites, one of which is octahedral and the other two tetrahedral. On the other hand, Fe(ClO4)3 reacted smoothly with H2DSALPTE in ethanol to give a mononuclear pseudo-octahedral complex in which the ligand functions in a dibasic hexadentate fashion. Mössbauer data suggest the presence of a low-spin-high-spin equilibrium in the solid state. The manganese(III) and cobalt(III) complexes of the Schiff base, H2DSALPTE, are also studied for the sake of comparison with the corresponding iron(III) complex. The N2S2 ligand, however, formed a low-spin pseudo-octahedral iron(III) complex. The complexes have been characterised by elemental analysis, molar conductance values, cryomagnetic data and i.r., electronic and Mössbauer spectral data. 相似文献
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