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排序方式: 共有859条查询结果,搜索用时 15 毫秒
851.
Kahaly S Yadav SK Wang WM Sengupta S Sheng ZM Das A Kaw PK Kumar GR 《Physical review letters》2008,101(14):145001
We demonstrate near-100% light absorption and increased x-ray emission from dense plasmas created on solid surfaces with a periodic sub-lambda structure. The efficacy of the structure-induced surface plasmon resonance, responsible for enhanced absorption, is directly tested at the highest intensities to date (3 x 10{15} W cm{-2}) via systematic, correlated measurements of absorption and x-ray emission. An analytical grating model as well as 2D particle-in-cell simulations conclusively explain our observations. Our study offers a definite, quantitative way forward for optimizing and understanding the absorption process. 相似文献
852.
The effect of Fe and Ni catalysts on the synthesis of carbon nanotubes (CNTs) using atmospheric pressure chemical vapor deposition
(APCVD) was investigated. Field emission scanning electron microscopy (FESEM) analysis suggests that the samples grow through
a tip growth mechanism. High-resolution transmission electron microscopy (HRTEM) measurements show multiwalled carbon nanotubes
(MWCNTs) with bamboo structure for Ni catalyst while iron filled straight tubes were obtained with the Fe catalyst. The X-ray
diffraction (XRD) pattern indicates that nanotubes are graphitic in nature and there is no trace of carbide phases in both
the cases. Low frequency Raman analysis of the bamboo-like and filled CNTs confirms the presence of radial breathing modes
(RBM). The degree of graphitization of CNTs synthesized from Fe catalyst is higher than that from Ni catalyst as demonstrated
by the high frequency Raman analysis. Simple models for the growth of bamboo-like and tubular catalyst filled nanotubes are
proposed. 相似文献
853.
Pankaj Chaturvedi Vinay Malvimat Gautam Sengupta 《The European Physical Journal C - Particles and Fields》2018,78(9):776
We propose a covariant holographic conjecture for the entanglement negativity of bipartite mixed states in \((1+1)\)-dimensional conformal field theories dual to bulk non static \(AdS_{3}\) configurations. Application of our conjecture to \((1+1)\)-dimensional conformal field theories dual to bulk non extremal and extremal rotating BTZ black holes exactly reproduce the corresponding entanglement negativity obtained through the replica technique, in the large central charge limit. We briefly discuss the issue of the generalization of our conjecture to higher dimensions. 相似文献
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855.
JPC – Journal of Planar Chromatography – Modern TLC - A simple and rapid high-performance thin-layer chromatographic (HPTLC) determination of ursolic acid (UA) in tissue is necessary... 相似文献
856.
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858.
Varun Kumar Sing Souvik Sur Mohd. Musharraf Ratan Kumar Dey Sanjay Kumar Swain Suman Shekhar 《Macromolecular Symposia》2024,413(1):2300045
In the present study, the degradation process of piperazine (PP) immobilized silica gel (SiPP) is investigated under dynamic conditions. The degradation of SiPP is studied with thermogravimetric analyzer (TGA). The kinetics of degradation process is analyzed by Kissinger method, Flynn–Wall–Ozawa's (FWO) method, and Deconvolution method. It is found that degradation of SiPP can be described by parallel independent two-portion process model, which includes two processing state of the system (marked by processes 1 and 2), where process 1 and 2 can be attributed to decomposition processes of organic moiety attached on silica surface. The apparent activation energy (Ea) is calculated by Flynn–Wall–Ozawa's (FWO) method and deconvolution method. 相似文献
859.