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161.
Jee Seong Kwak Nour Bizarri Dr. Sepideh Sharif Wenyao Peter Zhang Dr. Debasis Mallik Prof. Michael G. Organ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15505-15508
Optimization of the asymmetric synthesis of warfarin, an important anticoagulant, has been evaluated using a reconfigurable reaction platform capable of performing batch, continuous flow, and plug-flow synthesis. Further, this platform has been integrated with a novel, multidimensional, multiple variable analysis tool that can evaluate multiple critical quality attributes (CQA), percent conversion and enantiomeric excess in this case, from a single injection that is repeatedly recycled in a closed loop of chromatography columns, a detector and a heart-cut valve. Further, the new, integrated analysis system also facilitates validation of each QA, providing a high-level of confidence in analytical measurements, which are obtained without operator intervention. 相似文献
162.
Dipta Mukherjee Dyuman Das Arjun Dey Awadesh Kumar Mallik Jiten Ghosh Anand Kumar Sharma Anoop Kumar Mukhopadhyay 《Journal of Sol-Gel Science and Technology》2018,87(2):347-361
Phase pure, mesoporous, and crystalline V2O5 is synthesized by acid hydrolysis technique and subsequently heat treatment is carried out at 450, 500, 550, and 600?°C in air. The as-synthesized and heat-treated powders are thoroughly studied by X-ray diffraction, electron microscopy, dynamic light scattering, and spectroscopic techniques. A unique morphological tuning of V2O5 powders from as small as ~80?nm tiny nanorod to as large as a ~2.5?μm hexagonal grain as microstructural unit blocks is observed. A qualitative mechanism is suggested for particle growth. Further, the powders are pelletized and subsequently sintered in air at the same temperatures of 450, 500, 550, and 600?°C at which the powders were heat treated. Finally, nanomechanical properties of bulk pelletized V2O5 such as nanohardness and Young’s modulus are also evaluated by nanoindentation technique at nine different loads e.g., 10, 30, 50, 70, 100, 300, 500, 700, and 1000?mN. 相似文献
163.
Summary Gas chromatography has been employed for screening cyclic alkanols as selective solvents for the extraction of cyclohexane from an aromatic-free cyclohexane-rich fraction (77–81°C). The relative volatilities for close boiling hydrocarbons in all three cyclic alcohol solvents have been compared. Activity coefficient data at infinite dilution for nine binary hydrocarbon systems at 25°C have also been presented. 相似文献
164.
Hong Wang Jing Jing R. R. Mallik H. T. Chu P. N. Henriksen 《Journal of Crystal Growth》1993,130(3-4):571-577
Atomic force microscopy is used to image the surface relief of epitaxial Bi films grown on mica substrates. Monatomic terrace steps are readily resolved, which provide detailed information on crystal growth and defect structures. The films grow from the coalescence of isolated three-dimensional islands, however, each island grows layer-by-layer. The islands are triangular in shape and when they coalesce to form a continuous film, their structures are either in-phase, and consequently large crystallites are formed, or they are out-of-phase and defect structures are formed. The most common defects observed are twinning and stacking faults. Images showing the microscopic details of stacking faults, twinning, and grain boundaries are observed as a result of islands coalescing to form a continuous film. 相似文献
165.
Amperometric titration of mercury (in the range of 0-4 to 3.5 mg) has been carried out with 2-mercaptobenzoxazole with a stationary electrode in stirred solution in a sodium acetate-acetic acid medium. 相似文献
166.
The effective action for fermions moving in external gravitational and gauge fields is analyzed in terms of the corresponding external field propagator. The central object in our approach is the covariant energy-momentum tensor which is extracted from the regular part of the propagator at short distances. It is shown that the Lorentz anomaly, the conformal anomaly and the gauge anomaly can be expressed in terms of the local polynomials which determine the singular part of the propagator. (There are no coordinate anomalies.) Except for the conformal anomaly, for which we give explicit representations only ind<=4, we consider an arbitrary number of dimensions. 相似文献
167.
We propose a method of evaluation of the contribution of t-channel singularities for the photon-pion production process on the basis of dispersion relations for invariant amplitudes in the s-plane at fixed angle (cos ? = ± 1). These dispersion relations are studied in the approximation scheme of retaining only the contributions from exchanges at low energy, viz., N, N∗ (1237) in the s- and u-channels and π, ?, ω and A1 in the t-channel. It is shown that the dispersion relations require more accurate evaluation in general than what the above approximation scheme can provide in order that the information obtained about the t-channel be reliable. 相似文献
168.
Flexural and torsional natural frequencies of a shaft with periodically placed rotors and bearings are investigated by using a “wave approach”. By a judicious choice of parameters, it is possible to obtain ranges of operating speed that are free from both flexural and torsional resonances. Suggestions for widening such speed ranges are included. 相似文献
169.
D. D. Mallik 《Fluid Dynamics》1967,2(1):6-8
The plane flow of a perfectly conducting gas subject to a perpendicular magnetic field is considered. Ladikov [1] has solved this problem as a special case of the more general solution for a specific condition. It is shown that, following the method of [2], this problem may be reduced to the determination of the unknown function which satisfies a partial differential equation. Since the equation for is very complex, we have considered only two interesting cases, namely: 1) when the motion is irrotational, and 2) when the pressure is constant along the streamlines. 相似文献
170.
H. Bila V. Jakubsky M. Znojil B. Bagchi S. Mallik C. Quesne 《Czechoslovak Journal of Physics》2005,55(9):1075-1076
Inside a box of size L we contemplate the simplest
-symmetric piece-wise constant potential of size ℓ < L and purely imaginary strength ig and describe all its bound states in closed form.
Presented at the 3rd International Workshop “Pseudo-Hermitian Hamiltonians in Quantum Physics”, Istanbul, Turkey, June 20–22,
2005. 相似文献