排序方式: 共有86条查询结果,搜索用时 15 毫秒
21.
Since 1888, the liquid crystal display (LCD) industry is facing a fierce competition due to serious limitations such as poor contrast ratio and response time. Although some new materials have offered new applications and opened new markets for LCDs, materials with improved contrast ratio are highly desirable in LCD industry to sustain in the current market. This work reports a new behaviour in nano-material-doped liquid-crystal composite which is suitable for eradicating limitations of contrast ratio. Here, a high concentration of carbon nanotubes (CNTs) is doped in liquid crystal (LC) materials wherein the CNTs form aggregates in the LC composition. In these heavily doped samples, the phase change takes place with application of bias. This reversible process improves the contrast ratio as the material oscillates between crystalline and LC phases with field. 相似文献
22.
Vandana Singh Preeti Srivastava Angela Singh Devendra Singh Tulika Malviya 《高分子科学杂志,C辑:聚合物评论》2016,56(1):113-136
This article discusses and reviews the current status and future perspectives of silica hybrids of polysaccharides and biosilicas derived thereof. The hybrids have been produced in various morphological shapes and utilized in water remediation, separation, enzyme immobilization, sensor, and biomedical fields. The polysaccharides show templating and structure directing influence in manipulation of sol gel silica hybrid materials which can be calcined to derive functional biosilicas. The development of energy storage devices and white light emitting solid phosphors may be the fields of future research. 相似文献
23.
Russian Journal of Electrochemistry - A novel, convenient and economical method was developed for the anodic thiocyanation of nitrogen-containing aromatic and heteroaromatic compounds by constant... 相似文献
24.
Zn[(l)proline]2 has been found to be an efficient catalyst for the synthesis of pyrazole derivatives in pure water at room temperature. Reaction afforded moderate to excellent yield within a lesser time. Various pyrazoles which could not be prepared by other methods can be easily prepared by this method efficiently. Catalyst exhibits recyclability up to five runs. Hence our present protocol is economical and clean comprise of green reagent, solvent and catalyst. 相似文献
25.
Vinit SharmaPriyanka Manchanda Pankaj K. SahotaRalph Skomski Arti Kashyap 《Journal of magnetism and magnetic materials》2012,324(5):786-791
Density-functional calculations are used to determine the electronic structure and magnetic properties of dilute magnetic semiconductors with the composition X1−xMnxN (X=Al, Ga, In, x=6.25% and 12.5%). Emphasis is on the interatomic exchange as a function of the Mn-Mn distance. Our superlattice calculations show that the Mn dopants are spin-polarized with a half-metallic band gap and a magnetic moment of 4 μB per Mn atom at x=6.25 and 12.5%. The Mn (3d) bands lie in the band gap but partially hybridize with valence band or N 2p electrons, depending on the group-III element and on the spin direction. To calculate the exchange interaction parameters Jij, we have used a Green-function approach. The interaction between Mn atoms extends over several interatomic interactions and is mediated by nitrogen (2p) electrons. The exchange is always ferromagnetic and largest for the first nearest neighbors, but substantial ferromagnetic interactions persist over Mn-Mn distances up to sixth nearest neighbors in the considered supercell. 相似文献
26.
A large library of diversified compounds (pyrano [2,3-d]pyrimidines, pyrido[2,3-d] pyrimidines and a variety of spirooxindoles) were synthesized through a very efficient, economical and environmentally benign
process utilizing magnetic nanoparticles. Ease of recovery using an external magnetic field is an additional ecofriendly attribute
of this catalytic system. Most of the compounds are new; therefore, could be further explored for their pharmaceutical application.
Moreover, column chromatography and recrystallisation of the products is not required as the crude products are already highly
pure and hence can be used for target oriented synthesis on a wide scale. 相似文献
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Analytical and numerical study of the stability of sheet electron beam in periodically cusped magnetic field (PCM) is made.
The beam has been considered as having diffused density profile. The conditions for beam focusing are discussed. 相似文献
29.
We present using simple scaling arguments and one step replica symmetry breaking a theory for the localization of semiflexible polymers in a quenched random environment. In contrast to completely flexible polymers, localization of semiflexible polymers depends not only on the details of the disorder but also on the ease with which polymers can bend. The interplay of these two effects can lead to the delocalization of a localized polymer with an increase in either the disorder density or the stiffness. Our theory provides a general criterion for the delocalization of polymers with varying degrees of flexibility and allows us to propose a phase diagram for the highly folded (localized) states of semiflexible polymers as a function of the disorder strength and chain rigidity. 相似文献
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