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241.
Dynamics of self-focusing and self-phase modulation of elliptic Gaussian laser beam in a Kerr-medium 总被引:1,自引:0,他引:1
Using a direct variational technique involving elliptic Gaussian laser beam trial function, the combined effect of non-linearity
and diffraction on wave propagation of optical beam in a homogeneous bulk Kerr-medium is presented. Particular emphasis is
put on the variation of beam width and longitudinal phase delay with the distance of propagation. It is observed that no stationary
self-trapping is possible. The regularized phase is also seen to be always negative. 相似文献
242.
243.
Reaction of potassium salt of N‐aryliminopyrrole ligand [2‐(2, 6‐iPr2C6H3N=CH)–C4H3NK] ( 1 ) with samarium tris‐boro‐hydride [Sm(BH4)3(THF)3] gave a samarium ate complex [η2‐{2‐(2, 6‐iPr2C6H3N=CH)–C4H3N}3Sm(η1‐BH4){K(THF)6] ( 2 ); whereas similar treatment with erbium borohydride [Er(BH4)3(THF)3] afforded the mono(iminopyrrolyl) complex [η2‐{2‐(2, 6‐iPr2C6H3N=CH)–C4H3N}Er(η3‐BH4)2(THF)2] ( 3 ). In the solid‐state structures, the samarium complex 2 shows a rarely observed η1 and the erbium complex 3 shows a usual η3 coordination mode of the borohydrido ligand. 相似文献
244.
Santanu Chand Gaurav Verma Arun Pal Shyam Chand Pal Prof. Shengqian Ma Dr. Madhab C. Das 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(46):11804-11810
Accumulation of high concentrations of Al(III) in body has a direct impact on health and therefore, the trace detection of Al(III) has been a matter for substantial concern. An anionic metal organic framework ({[Me2NH2]0.5[Co(DATRz)0.5(NH2BDC)] ⋅ xG}n; 1 ; HDATRz=3,5-diamino-1,2,4-triazole, H2NH2-BDC=2-amino-1,4-benzenedicarboxylic acid, G=guest molecule) composed of two types of secondary building units (SBU) and channels of varying sizes was synthesized by employing a rational design mixed ligand synthesis approach. Free −NH2 groups on both the ligands are immobilized onto the pore surface of the MOF which acts as a superior luminescent sensor for turn-on Al(III) detection. Furthermore, the large channels could allow the counter-ions to pass through and get exchanged to selectively detect Al(III) in presence of other seventeen metal ions with magnificent luminescence enhancement. The observed limit of detection is as low as 17.5 ppb, which is the lowest among the MOF-based sensors achieved so far. To make this detection approach simple, portable and economic, we demonstrate MOF filter paper test for real time naked eye observation. 相似文献
245.
Akanksha Gupta Chaudhary Anubha Vashisht Hari Shankar Shyam Ashok Singh Malhi Rajiv Gupta 《Macromolecular Symposia》2024,413(1):2300092
The plastic waste crisis is a major environmental challenge facing the world today. The overuse and improper disposal of plastic materials have caused significant damage to the environment, affecting the health of both humans and animals. The adoption of sustainable alternatives to plastic, such as polymer-based materials, is crucial to addressing this issue. In the Indian context, polymer-based sustainability has created new growth potential for the packaging sector. This study has improved consumer behavior and raised income by gaining an understanding of and access to customers' digital awareness of polymer-based sustainability. In addition to its role in communication and attracting consumer attention, packaging must align with modern environmental standards for preservation methods to meet the growing consumer demand for eco-friendly products and environmentally conscious companies. In keeping with the objectives, this paper employs a method for analyzing current research on the influence of polymer-based sustainability esthetics on consumer behavior. The research design is quantitative. The model of the literature review is used to develop the structured questionnaire. The results show that digital awareness significantly influences consumer perceptions of polymer-based sustainability. The study recommends that manufacturers of polymer-based materials invest in digital awareness campaigns to increase consumer acceptance and promote sustainability. 相似文献
246.
247.
Shyam Shirali Filadelfo Guzman Donald C. Weber Ashot Khrimian 《Tetrahedron letters》2017,58(21):2066-2068
We recently synthesized all stereoisomers of 1,10-bisaboladien-3-ol and 10,11-epoxy-1-bisabolen-3-ol, including three stink bug pheromones, via a rhodium-catalyzed asymmetric addition of trimethylaluminum to diastereomeric mixtures of cyclohex-2-enones. However, yields of trans isomers were low, and scaling reactions using expensive catalysts were cumbersome. Now we describe a new synthesis of bisabolenol stink bug pheromones via (S)- and (R)-4-((R)-6-methylhept-5-en-2-yl)cyclohex-2-enones prepared by enantioselective Michael additions of methyl vinyl ketone to (S)- and (R)-citronellals and lithium hydroxide monohydrate-catalyzed stereoselective cyclizations of intermediate ketoaldehydes. Addition of methyllithium to these enones provided cis- and trans-1,10-bisaboladien-3-ols, which were separated by chromatography on silica and further converted to 10,11-epoxy-1-bisabolen-3-ols. Thus, we developed more convenient syntheses of pheromones of the rice stink bug, the harlequin bug, and brown marmorated stink bug. 相似文献
248.
Rele SM Cui W Wang L Hou S Barr-Zarse G Tatton D Gnanou Y Esko JD Chaikof EL 《Journal of the American Chemical Society》2005,127(29):10132-10133
A new class of high molecular weight polysulfated PEO dendrimer-like glycopolymer has been synthesized by a combination of arm-first and core-first methodologies followed by trichloroacetimidate glycosidation as a facile bioconjugation strategy. An L-selectin antagonist was identified that exhibits 103-fold greater activity than other multivalent sLex glycopolymers and 20-50 times greater potency than other linear heparinoids. A significant reduction in inflammatory cell recruitment was observed in vivo. 相似文献
249.
Convenient Synthesis of Novel Quinazoline Congeners via Copper Catalyzed C–N/C–S Coupling and Their Biological Evaluation 下载免费PDF全文
Harshad P. Lakum Dhruvin R. Shah Kishor H. Chikhalia 《Journal of heterocyclic chemistry》2016,53(1):209-219
A library of novel quinazoline scaffolds endowed with semicarbazide/oxadiazole thiol motif synthesized via an efficient and sustainable copper catalyzed C–N/C–S coupling is reported, making the presented methodology extremely valuable from economic and environmental point of view. Among the all synthesized compounds screened for in vitro antibacterial, antifungal, and anti‐TB activity, 7b , 7c , 7f , 9b , 9c , 9i , and 9j showed excellent inhibitory effect on particular strain of bacteria, fungi, and M. tuberculosis H37Rv as well. All the newly synthesized derivatives were well characterized by their IR, 1H NMR, 13C NMR, mass spectroscopy as well as elemental analysis. 相似文献
250.
A comparative study of different energy loss formulations viz. Benton and Henke, Mukherjee and Nayak, Zieglar et al. and Hubert et al. has been done at lower energies (0.5 to 5 MeV/n) with the aim to identify their relative validity in this energy range. Calculated results using these formulations have been compared with experimental results available in literature. 相似文献