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51.
T. Aziz S. Ahmad H. Ahrar S. B. Beri V. S. Bhatia S. N. Ganguli S. K. Gupta V. K. Gupta A. Gurtu G. L. Kaul Manjit Kaur A. R. Khan S. Kumar P. K. Malhotra L. K. Mangotra I. S. Mittra Y. Prakash N. K. Rao M. Shafi M. Shyam G. Singh S. K. Tuli Aligharh Collaboration Bombay Collaboration Chandigarh Collaboration Jammu Collaboration Varanasi Collaboration 《Zeitschrift fur Physik C Particles and Fields》1985,27(3):325-328
52.
Giuseppe Giordano Krishnamurthy Shyam Alan C. Sartorelli Walter J. McMurray 《Journal of mass spectrometry : JMS》1992,27(5):633-635
Several 1,2,2-tris(sulfonyl)hydrazines, conceived as prodrugs of 1,2-bis(sulfonyl)hydrazines and synthesized as potential antineoplastic and trypanocidal drugs, were analyzed by mass Spectrometry as part of the confirmation of the structure of these compounds. Since these compounds showed activity against several transplanted animal tumors, an understanding of the mass spectral behavior of these agents is important to gain information should clinical trials and metabolic studies be undertaken. In all spectra, protonated molecular ions were observed. Collision activation resulted in considerable fragmentation in the fast atom bombardment spectra. Rearrangement ions formed by elimination of substituted diimides from the middle of the molecule were observed. Other rearrangements involving the alkyl substituent and sulfonyl oxygen also occurred. 相似文献
53.
Technique and instrumentation to detect reliably, multiplicity of neutrons emitted in sharp bursts (≤100 μs) has been developed
where a burst of as low as 15 neutrons and continuous emission of ⋍10−1 neutron/s may be detected. Using this technique, attempts were made to detect neutron emission from various experiments in
which anomalous nuclear effects (or what is commonly referred to as cold fusion) may be expected to occur. No neutrons, above
our detection threshold, were detected in the recent series of experiments. 相似文献
54.
Numerical differentiation can uncover hidden features in chemical data, but the limitations of the technique used should be understood. A method based on fitting data to a quadratic polynomial gives good signal-to-noise ratios, but systematically low derivative intensities. Central difference methods are more accurate but less tolerant of noise. 相似文献
55.
56.
R.M. Mehra P.C. Mathur A.K. Kathuria Radhey Shyam 《Journal of Physics and Chemistry of Solids》1978,39(3):295-298
D.C. conductivity measurements have been made as a function of temperature and external electric field on bulk amorphous selenium. A decrease in the activation energy with increase of electric field has been observed. This has been interpreted in terms of a mixed, thermally activated and trap limited conduction process. 相似文献
57.
58.
O. S. Narayanaswamy Shyam K. Samanta 《Journal of the mechanics and physics of solids》1982,30(6):427-445
Springback of rectangular bars under combined torsion and tension is investigated. A theoretical model for springback is developed and evaluated by comparing calculated and experimental results. It is concluded that springback is analytically predictable. Both analysis and test data show that an axial tension always reduces angular springback in a twisted bar. The order of plastic deformation is found to be important : twist followed by pull produces smaller angular springback upon release of torque and force than does a deformation in the reverse order. 相似文献
59.
Feature-preserved denoising is of great interest in medical image processing. This article presents a wavelet-based bilateral filtering scheme for noise reduction in magnetic resonance images. Undecimated wavelet transform is employed to provide effective representation of the noisy coefficients. Bilateral filtering of the approximate coefficients improves the denoising efficiency and effectively preserves the edge features. Denoising is done in the square magnitude domain, where the noise tends to be signal independent and is additive. The proposed method has been adapted specifically to Rician noise. The visual and the diagnostic quality of the denoised image is well preserved. The quantitative and the qualitative measures used as the quality metrics demonstrate the ability of the proposed method for noise suppression. 相似文献
60.
We study the action for the three-space formalism of general relativity, better known as the Barbour–Foster–Ó Murchadha action, which is a square-root Baierlein–Sharp–Wheeler action. In particular, we explore the (pre)symplectic structure by pulling it back via a Legendre map to the tangent bundle of the configuration space of this action. With it we attain the canonical Lagrangian vector field which generates the gauge transformations (3-diffeomorphisms) and the true physical evolution of the system. This vector field encapsulates all the dynamics of the system. We also discuss briefly the observables and perennials for this theory. We then present a symplectic reduction of the constrained phase space. 相似文献