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41.
K. Singh S. Sihotra S. S. Malik J. Goswamy D. Mehta N. Singh R. Kumar R. P. Singh S. Muralithar E. S. Paul J. A. Sheikh C. R. Praharaj 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):321-324
The collective band structures of the 125Cs nucleus have been investigated by in-beam γ-ray spectroscopic techniques following the 110Pd ( 19F, 4n) reaction at 75MeV. The previously known level scheme, with rotational bands built on πg7/2, πg9/2 and πh11/2 orbitals, has been extended and evolves into bands involving rotationally aligned ν(h11/2)2 and π(h11/2)2 quasiparticles. A strongly coupled band has been reassigned a high-K πh11/2 ⊗ νg7/2 ⊗ νh11/2 three-quasiparticle configuration and a new side band likely to be its chiral partner has been identified. Configurations
assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model calculations. 相似文献
42.
Gouda A. A. El Sheikh R. El Sayed H. M. Khedr A. M. Al Ezz Sh. Abo Gamil W. Hamdy M. 《Journal of Applied Spectroscopy》2022,89(3):567-578
Journal of Applied Spectroscopy - A new, green, simple, and validated ultrasound-assisted dispersive microsolid-phase extraction method applying unprecedented adsorbent-modified multiwalled carbon... 相似文献
43.
Herein, a new Cu(II) Schiff base complex was immobilized onto the magnetic graphene oxide surface through a stepwise procedure. The as-synthesized nanostructure (GO/Fe3O4/CuL) was characterized by various techniques including Fourier transform infrared (FT-IR), Raman spectroscopies, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), energy-dispersive X-ray (EDX) and inductively coupled plasma (ICP) spectroscopies, N2 adsorption–desorption analysis, vibrating sample magnetometry (VSM), and X-ray diffraction (XRD). The catalytic activity of the synthesized nanocatalyst was examined in 4-nitrophenol (4-NP), Congo red (CR), and methylene blue (MB) reduction using NaBH4 in an aqueous solution at room temperature. The reaction progress was monitored by UV–Vis spectroscopy. Also, the synthesized nanostructure was evaluated as an efficient catalyst for the synthesis of 2-amino-4H-benzopyrans via three-component reactions of 1-naphthol, malononitrile, and various aldehydes in ethanol/water at 50°C. The use of green solvents, the short reaction time, the high product yield, and easy separation from the reaction environment are the main benefits of this catalytic system. By covalent grafting of the complex on the graphene oxide surface, its catalytic performance significantly increased compared with graphene oxide; this is probably related to the chemical change of the graphene oxide surface. The results show the high chemical stability and the improved reusability of the synthesized nanocatalyst (six times) without significant loss in the catalytic activity of GO/Fe3O4/CuL nanocomposite. 相似文献
44.
Intermolecular stacking in pyrazolo[3,4‐d]pyrimidine‐based pentamethylene‐linked flexible molecules
Kamlakar Avasthi Sheikh M. Farooq Ashish K. Tewari Ashoke Sharon Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o42-o45
The crystal structures of 1‐{5‐[4,6‐bis(methylsulfanyl)‐2H‐pyrazolo[3,4‐d]pyrimidin‐2‐yl]pentyl}‐6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C22H29N9S3, and 6‐methylsulfanyl‐1‐{5‐[6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo[3,4‐d]pyrimidin‐2‐yl]pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C25H34N10S2, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo[3,4‐d]pyrimidine rings. 相似文献
45.
A new PVC membrane potentiometric sensor that is highly selective to Fe(III) ions was prepared by using 2-[(2-hydroxy-1-propenyl-buta-1,3-dienylimino)-methyl]-4-p-tolylazo-phenol [HPDTP] as a suitable carrier. The electrode exhibits a linear response for iron(III) ions over a wide concentration range (3.5 × 10−6 to 4.0 × 10−2) with a super Nernstian slope of 28.5 (±0.5) per decade. The electrode can be used in the pH range from 4.5 to 6.5. The proposed sensor shows fairly a good discriminating ability towards Fe3+ ion in comparison to some hard and soft metals such as Fe2+, Cd2+, Cu2+, Al3+ and Ca2+. It has a response time of <15 s and can be used for at least 2 months without any measurable divergence in response characteristics. The electrode was used in the direct determination of Fe3+ in aqueous samples and as an indicator electrode in potentiometric titration of Fe(III) ions. 相似文献
46.
Shabir A. Parah Nazir A. Loan Asif A. Shah Javaid A. Sheikh G. M. Bhat 《Nonlinear dynamics》2018,93(4):1933-1951
The proliferation of information and communication technology has made exchange of information easier than ever. Security and copyright protection of multimedia contents in such a scenario has become a major challenge for the research community round the globe. Digital watermarking has been found as an effective tool for protection and security of multimedia content. A secure and robust watermarking scheme based on DC coefficient modification in pixel domain and a modified logistic map is presented in this paper. The cover image is divided into \(8 \times 8\) sub-blocks and instead of computing DC coefficient using discrete cosine transform (DCT), we compute DC coefficient of each block in spatial domain. Watermark bits are embedded by modifying DC coefficients of various blocks in spatial domain. The quantum of change to be brought in various pixels of a block for embedding watermark bit depends upon DC coefficient of respective blocks, nature of watermark bit (0 or 1) to be embedded and the adjustment factor. The security of embedded watermark has been taken care of by using chaotic encryption based on a generalized logistic map (GLM). We show that GLM has better properties like ergodicity, larger lyapunov exponent, uniform invariant density, mixing, higher range of bifurcation parameter etc., compared to basic logistic map. We exploit these properties of GLM for designing a secure robust, strong efficient cryptosystem to encrypt the watermark information before embedding it. Experimental investigations show that besides being highly secure the proposed technique is robust to both signal processing and geometric attacks. Further, the proposed scheme is computationally efficient as DC coefficient which holds the information is computed in pixel domain instead of using DCT on an image block. 相似文献
47.
Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard universal sd-shell (USD) interaction and the canonical partition function constructed from the calculated eigensolutions. It is shown that the extracted average quadrupole moments show a transitional behaviour as a function of temperature and the infered transitional temperature is shown to vary with angular momentum. The quadrupole deformation of the individual eigenstate is also analysed. 相似文献
48.
Fabrication of fibrous patterned architectures with controlled deposition and multidirectional alignment 下载免费PDF全文
In recent years, the ability to produce nanofibrous patterned architectures by electrospinning has exposed a wide range of potential applications in biomedical and industrial fields. Directional alignment, controlled deposition, and density variation into the patterns are desirable for many applications such as tissue engineering scaffolds and micro/nano‐electronic devices. In this study, we introduce a versatile method for fabrication of various kinds of nanofibrous deposition patterns with the help of microprocessor based control system for switching collector electrodes. By controlling the concurrent activation time of two adjacent electrodes, we demonstrated that amount of fibers going into the pattern can be adjusted and alignment in electrospun fibers can be obtained. We also revealed that the deposition density of electrospun fibers in different areas of patterned architectures can be varied. This advanced technique can have a significant impact in enhancing the technology of electrospinning and can help develop new applications in health sciences and industrial sectors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
49.
Salman Nisar Sohaib Z. Khan Muhammad Ali Lin Li Mohammed A. Sheikh 《Journal of Russian Laser Research》2014,35(2):182-192
Laser cutting of glass using the controlled fracture technique leads to cut path deviation at the leading and trailing edges of the float glass sheet. In this technique, thermal stresses are used to induce the crack, and the material is separated along the cutting path by extending the crack. We show that the cut path deviation is partly due to high magnitudes of thermal stresses generated near the sheet edges. The absorption of intense radiation from the CO2 and diode laser beams in the glass causes local temperature increases and consequently generates different thermal fields and stress distributions due to surface and volumetric heat absorption. In this paper, we report the effect of the CO2 and diode laser wavelength interaction with the float glass and its effect on the magnitudes of thermal stresses generated near the edges of the glass sheet. We simulate the distribution of the thermal stress and temperature using finite-element analysis software Abaqus and validate it against the experimental data. We show that the CO2 laser produces a lower surface quality and a larger cut path deviation at the leading and trailing edges of the glass sheet as compared to the diode laser. 相似文献
50.
Synthesis of substituted phenanthridinones and dibenzoazepinones has been realized from 2-halo-benzamides in the presence of potassium tert-butoxide and a catalytic amount of 1,10-phenanthroline or AIBN. This new carbon-carbon bond forming reaction gives direct access to various biaryl lactams containing six- and seven-membered rings chemoselectively. Carbon-carbon coupling seems to proceed by the generation of a radical in the amide ring which leads to C-H arylation of aniline. 相似文献