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11.
Imaging characteristics of toroidal and ellipsoidal mirrors for synchrotron radiation source Indus-1
We discuss and compare the imaging characteristics of toroidal and ellipsoidal mirrors for different horizontal acceptances
of synchrotron radiation source Indus-1; using a ray tracing method. It has been shown that the toroidal and ellipsoidal mirrors
have similar focussing behaviour at small horizontal acceptances. For large horizontal acceptances, toroidal mirror shows
an asymmetry in the focussed image. Though the data used here are for Indus-1, the results are generally valid for any bending
magnet synchrotron radiation source incident at grazing angles on these mirrors. 相似文献
12.
13.
The effect of muddled base pair on electron transfer through a deoxyribonucleic acid (DNA) molecule connected to the gold electrodes has been elucidated using tight binding model. The effect of hydrogen and nitrogen bonds on the resistance of the base pair has been minutely observed. Using the semiempirical extended Huckel approach within NEGF regime, we have determined the current and conductance vs. bias voltage for disordered base pairs of DNA made of thymine (T) and adenine (A). The asymmetrical behaviour amid five times depreciation in the current characteristics has been observed for deviated Au–AT base pair–Au devices. An interesting revelation is that the conductance of the intrinsic AT base pair configuration attains dramatically high values with the symmetrical zig-zag pattern of current, which clearly indicates the transformation of the bond length within the strands of base pair when compared with other samples. A thorough investigation of the transmission coefficients T(E) and HOMO–LUMO gap reveals the misalignment of the strands in base pairs of DNA. The observed results present an insight to extend this work to build biosensing devices to predict the abnormality with the DNA. 相似文献
14.
The application of a two dimensional (2D) grating interferometer-Fresnel zone plate combination for quantitative submicron phase contrast imaging is reported. The combination of the two optical elements allows quick recovery of the phase shift introduced by a sample in a hard X-ray beam, avoiding artifacts observed when using the one dimensional (1D) interferometer for a sample with features oriented in the unsensitive direction of the interferometer. The setup provides submicron resolution due to the optics magnification ratio and a fine sensitivity in both transverse orientations due to the 2D analysis gratings. The method opens up possibilities for sub-micro phase contrast tomography of microscopic objects made of light and/or homogeneous materials with randomly oriented features. 相似文献
15.
Woonghee Tim Huh Ganesh JanakiramanPeter L. Jackson Nidhi Sawhney 《Operations Research Letters》2003,31(5):366-374
This paper studies minimizing the flow time of a cyclic schedule for repeated identical jobs, where one job is started/completed in each cycle, subject to the schedule achieving maximum throughput. We propose a branch and bound method for a single machine problem, and use this method to derive an improved lower bound for the multiple machine problem. 相似文献
16.
The reaction of the enaminoketones ( 2 or 5 ) of 2-acyl-1,3-indandiones with unsymmetrical hydrazines results in the regiospecific synthesis of 1,3- or 2,3-disubstituted indeno[1,2-c]pyrazol-4(1H)-ones ( 4 or 7 ). The synthesis of the enaminoketones ( 2 or 5 ) is accomplished by way of amine addition to the 2-acyl-1,3-indandiones 8a-c or by reduction of the indenoisoxazole 9 . The structural assignment of the isomeric indenopyrazoles 4 and 7 is based upon 1H-nmr chemical shifts. 相似文献
17.
Calculated vapor pressures have been used to estimate the composition of the vapor over an equimolar mixture of linear alkanes and to make inferences about the effects of pressure on the thermal degradation of polyethylene as studied using thermogravimetry. The troublesome bubbling in molten PE degrading under vacuum conditions has been related to the boiling out of molecules in the range C30 to >C80. The effect of pressure in lowering the apparent overall activation energy has been ascribed to contributions from the lalent heats of vaporization of molecules in the range C15 to ~C30. 相似文献
18.
Sulekh Chandra Krishna B. Pandeya Gulshan L. Sawhney Jagdish S. Baijal 《Transition Metal Chemistry》1980,5(1):80-82
Summary Mössbauer studies of high-spin iron(II) complexes of the type FeL2X2 [L = cyclohexanonesemicarbazone (CHSC); X = Cl, NO3, 0.5 SO4, NCS] have been carried out at room and at liquid nitrogen temperature. The results reveal doublet ground states for Fe(CHSC)2Cl2 and Fe(CHSC)2(NO3)2 and singlet ground states for Fe(CHSC)2SO4 and Fe(CHSC)2(NCS)2. 相似文献
19.
Dr. M. Anne Sawhney Dr. Malik Wahid Dr. Santanu Muhkerjee Rebecca Griffin Prof. Alexander Roberts Prof. Satishchandra Ogale Dr. Jenny Baker 《Chemphyschem》2022,23(5):e202100860
Before the viability of a cell formulation can be assessed for implementation in commercial sodium ion batteries, processes applied in cell production should be validated and optimized. This review summarizes the steps performed in constructing sodium ion (Na-ion) cells at research scale, highlighting parameters and techniques that are likely to impact measured cycling performance. Consistent process-structure-performance links have been established for typical lithium-ion (Li-ion) cells, which can guide hypotheses to test in Na-ion cells. Liquid electrolyte viscosity, sequence of mixing electrode slurries, rate of drying electrodes and cycling characteristics of formation were found critical to the reported capacity of laboratory cells. Based on the observed importance of processing to battery performance outcomes, the current focus on novel materials in Na-ion research should be balanced with deeper investigation into mechanistic changes of cell components during and after production, to better inform future designs of these promising batteries. 相似文献
20.
M. K. Tiwari L. Alianelli I. P. Dolbnya K. J. S. Sawhney 《Journal of synchrotron radiation》2010,17(2):237-242
In this paper the first practical application of kinoform lenses for the X‐ray reflectivity characterization of thin layered materials is demonstrated. The focused X‐ray beam generated from a kinoform lens, a line of nominal size ~50 µm × 2 µm, provides a unique possibility to measure the X‐ray reflectivities of thin layered materials in sample scanning mode. Moreover, the small footprint of the X‐ray beam, generated on the sample surface at grazing incidence angles, enables one to measure the absolute X‐ray reflectivities. This approach has been tested by analyzing a few thin multilayer structures. The advantages achieved over the conventional X‐ray reflectivity technique are discussed and demonstrated by measurements. 相似文献