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排序方式: 共有738条查询结果,搜索用时 156 毫秒
731.
S. Verma J. J. Das A. Jhingan K. Kalita S. Barua K. S. Golda N. Madhavan P. Sugathan S. Nath T. Varughese J. Gehlot S. Mandal Ranjit P. K. Sahu B. John B. K. Nayak V. Jha A. Saxena S. K. Datta R. Singh 《The European Physical Journal A - Hadrons and Nuclei》2010,44(3):385-392
Quasielastic scattering angular distributions have been measured for the 7Be + 9Be system at E lab = 17 , 19 and 21MeV in the angular range $ \theta_{{cm}}^{}$ = 24° - 57° . An optical model (OM) analysis of these data has been carried out in order to extract optical potential parameters and reaction cross-sections. One-proton stripping cross-sections were also measured for this system at E lab = 19 and 21MeV. These transfer angular-distribution data were compared with the finite-range distorted-wave Born approximation (FRDWBA) calculations. For the 7Li + 9Be system quasielastic scattering angular distributions were measured and emitted light charged particles were detected at E lab = 15.75 , 24.00 and 30.00MeV in the angular range $ \theta_{{cm}}^{}$ = 7° - 70° . Fusion cross-sections were obtained by reproducing the measured $ \alpha$ -evaporation spectra from the compound nucleus at backward angles with the statistical model calculations. The ratios of the experimental fusion cross-sections to the total reaction cross-sections (obtained from OM analysis) were found to be small. This result suggests that the break-up process has a strong influence on the fusion process leading to a reduction in the fusion cross-section. 相似文献
732.
Alok K. Jha 《Journal of magnetism and magnetic materials》2010,322(18):2653-2657
Magnetization studies of YBCO:BaZrO3 composite superconductor have been done over a wide range of temperature and applied magnetic field using MPMS SQUID VSM and the results are compared with that of pure YBCO. The analysis of the observed results indicate that there is considerable improvement in the values of critical current density (JC) and pinning force density (Fp) of YBCO:BaZrO3 composite samples as compared to pure YBCO sample in the entire investigated range of applied magnetic field and temperatures ranging from 4 to 77 K. The variation of JC with reduced temperature t (=T/TC) for the composite samples has been found to be similar to that of pure YBCO sample indicating similar nature of the vortex interaction with pinning centres in both pure and composite samples. The enhancement in the value of JC and Fp in the composite samples as compared to pure YBCO sample has been attributed to the increased defect density in the composite samples due to the presence of BZO particles in YBCO matrix. 相似文献
733.
Sanjeev K. Gupta Rucha Desai Prafulla K. Jha Satyaprakash Sahoo D. Kirin 《Journal of Raman spectroscopy : JRS》2010,41(3):350-355
Titanium dioxide nanocrystals were prepared by the wet chemical method and characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), Raman scattering (RS) and photoluminescence techniques. The XRD pattern shows the formation of single phase anatase structure of average sizes ∼7 nm (sample A) and ∼15 nm (sample B) for two samples. Additionally, TEM and RS were used to confirm the anatase crystal structure for both samples. The PL spectra show that the intensity of the sample A is more than that of sample B, which has been attributed to defect(s) and particle size variation. A modified phonon confinement model incorporating particle size distribution function and averaged dispersion curves for two most dispersive phonon branch (Γ‐X direction) have been used to interpret the size effect in Raman spectra. The obtained Raman peak shift and full width at half‐maximum agree well with the experimental data. Our observations suggest that the phonon confinement effects are responsible for a significant shift and broadening for the Raman peaks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
734.
This paper presents an analytical investigation of steady, fully developed MHD Couette flow of viscous, incompressible, electrically conducting fluid in the presence of radial magnetic field. Exact solutions are derived for the governing energy and momentum equations by taking into account the effects of viscous and Joule dissipations under relevant boundary conditions. The solutions obtained are graphically represented and the effects of various controlling parameters such as Hartmann number and Brinkman number on the temperature profile and consequently the Nusselt numbers are discussed. The significant result from the study is that increase in Hartmann number leads to enhancement on the Nusselt number at outer surface of inner cylinder while the role of Hartmann number is just reverse on Nusselt number at inner surface of outer cylinder. In addition, the Brinkman number has an insignificant effect on the Nusselt numbers when both surfaces are kept at equal temperature. 相似文献
735.
Juman Mohammed Rasmi Alamil Keshav Raj Paudel Yinghan Chan Dikaia Xenaki Jithendra Panneerselvam Sachin Kumar Singh Monica Gulati Niraj Kumar Jha Deepak Kumar Parteek Prasher Gaurav Gupta Raniya Malik Brian George Oliver Philip Michael Hansbro Kamal Dua Dinesh Kumar Chellappan 《Molecules (Basel, Switzerland)》2022,27(9)
The inflammatory response is a central aspect of the human immune system that acts as a defense mechanism to protect the body against infections and injuries. A dysregulated inflammatory response is a major health concern, as it can disrupt homeostasis and lead to a plethora of chronic inflammatory conditions. These chronic inflammatory diseases are one of the major causes of morbidity and mortality worldwide and the need for them to be managed in the long term has become a crucial task to alleviate symptoms and improve patients’ overall quality of life. Although various synthetic anti-inflammatory agents have been developed to date, these medications are associated with several adverse effects that have led to poor therapeutic outcomes. The hunt for novel alternatives to modulate underlying chronic inflammatory processes has unveiled nature to be a plentiful source. One such example is agarwood, which is a valuable resinous wood from the trees of Aquilaria spp. Agarwood has been widely utilized for medicinal purposes since ancient times due to its ability to relieve pain, asthmatic symptoms, and arrest vomiting. In terms of inflammation, the major constituent of agarwood, agarwood oil, has been shown to possess multiple bioactive compounds that can regulate molecular mechanisms of chronic inflammation, thereby producing a multitude of pharmacological functions for treating various inflammatory disorders. As such, agarwood oil presents great potential to be developed as a novel anti-inflammatory therapeutic to overcome the drawbacks of existing therapies and improve treatment outcomes. In this review, we have summarized the current literature on agarwood and its bioactive components and have highlighted the potential roles of agarwood oil in treating various chronic inflammatory diseases. 相似文献
736.
In this paper, simple relations are proposed for the calculation of Debye temperature θD and melting point Tmof II‐VI and III‐V zincblende semiconductors. Six relations are proposed to calculate the value of θD. Out of these six relations, two are based on plasmon energy data and the others on molecular weight, melting point, ionicity and energy gap. Three simple relations are proposed to calculate the value of Tm. They are based on plasmon energy, molecular weight and ionicity of the semiconductors. The average percentage deviation of all nine equations was calculated. In all cases, except one, it was estimated between 3.34 to 17.42 % for θD and between 2.37 to 10.45 % for Tm. However, in earlier correlations, it was reported between 10.59 to 33.38% for θD and 6.96 to 14.95% for Tm. The lower percentage deviation shows a significant improvement over the empirical relations proposed by earlier workers. The calculated values of θD and Tm from all equations are in good agreement with the available experimental values and the values reported by different workers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
737.
738.
The hitherto unreported compounds of general structure 3,3′-(alkanediyl)bis-(2,2,2-triaryl-1-oxa-2-stiba-3-azabenzo[d]cyclohex-5-ene) have been synthesized in 48-56% yields by the cyclization of the tetrasodium salt of N,N′-bis(2-hydroxybenzyl)-1,2-diaminoethane(II) or of N,N′-bis(2-hydroxybenzyl)-1,3-diaminopropane(II*) with R3SbBr2 (R = phenyl, p-tolyl, or mesityl). The tetrasodium salts were prepared by the reactions of the corresponding amines with sodium hydride. The amines (II and II*), in turn, were obtained by the sodium borohydride reduction of N,N′-bis(salicylidene)-1,2-diaminoethane and N,N′-bis-(salicylidene)-1,3,-diaminopropane, respectively. The heterocyclic compounds are air stable and moisture insensitive. These compounds have been characterized by elemental analyses, molecular weight determinations, and by IR, far IR, 1H, and 13C NMR spectral studies. © 1996 John Wiley & Sons, Inc. 相似文献