Results 21 to 30 of about 854,777 (264)

Chiroptical Properties and the Racemization of Pyrene and Tetrathiafulvalene-Substituted Allene: Substitution and Solvent Effects on Racemization in Tetrathiafulvalenylallene

Molecules, 2014
Dissymmetric 1,3-diphenylallene derivative 3 connected with 4,5-bis(methyl-thio)tetrathiafulvalenyl and 1-pyrenyl substituents was prepared and characterized. The molecular structure was determined by X-ray crystallographic analysis.
Masashi Hasegawa, Seiya Iwata, Yasuto Sone, Junta Endo, Hideyo Matsuzawa, Yasuhiro Mazaki   +5 more
doaj   +1 more source

Guest editorial—the ballyhoo over polar bears [PDF]

, 2009
Critics have said that there’s little or no justification for the focus that polar bears (Ursus maritimus) have received as a threatened species. Recent studies project dramatic reductions in polar bear numbers in just a few decades, in concert with the ...
Vongraven, Dag
core   +1 more source

Polar bears killed in Svalbard 1987–1992 [PDF]

, 1993
A total of 26 polar bears have been killed in Svalbard since January 1987. Fifteen of these cases were self defense, four precautionary measures, six acts of mercy and one unknown.
Gjertz, Ian, Hindrum, Reidar, Aarvik, Sissel   +2 more
core   +1 more source

Review of Climate change in the polar regions, by John Turner & Gareth J. Marshall [PDF]

, 2012
In this ambitious, cross-disciplinary volume, British Antarctic Survey scientists John Turner and Gareth Marshall synthesize what is known about climate change in the Arctic and Antarctic and compare the changes that have occurred in the two polar ...
Orheim, Olav
core   +1 more source

Inequalities concerning the rate of growth of polynomials involving the polar derivative [PDF]

, 2020
This paper contains some results for algebraic polynomials in the complex plane involving the polar derivative that are inspired by some classical results of Bernstein.
Mir, Abdullah, Malik, Adil Hussain, Abdullah Mir, Adil Hussain Malik   +3 more
core   +2 more sources

BODIPY-based dye for no-wash live-cell staining and imaging

BioTechniques, 2017
In nonpolar solvents, hydrophobic organic fluorophores often show bright fluorescence, whereas in polar media, they usually suffer from aggregation-caused quenching (ACQ).
Alexey A. Pakhomov, Igor E. Deyev, Natalia M. Ratnikova, Stepan P. Chumakov, Veronika B. Mironiuk, Yuriy N. Kononevich, Aziz M. Muzafarov, Vladimir I. Martynov   +7 more
doaj   +1 more source

Aerial strip surveys of polar bears in the Barents Sea [PDF]

, 1990
Aerial strip surveys of polar bears in the Barents Sea were performed by helicopter in winter 1987. The number of bears within 100 m on each side of the helicopter was counted. A total of 263.6 km2 was surveyed and 21 bears were counted.
Wiig, Øystein, Bakken, Vidar
core   +1 more source

Inequalities for the Polar Derivative of a Polynomial

Abstract and Applied Analysis, 2012
For a polynomial 𝑝(𝑧) of degree 𝑛, we consider an operator 𝐷𝛼 which map a polynomial 𝑝(𝑧) into 𝐷𝛼𝑝(𝑧)∶=(𝛼−𝑧)𝑝′(𝑧)+𝑛𝑝(𝑧) with respect to 𝛼. It was proved by Liman et al. (2010) that if 𝑝(𝑧) has no zeros in |𝑧|
Ahmad Zireh
doaj   +1 more source

Polar bear predation on ringed seals in the fast-ice of Hornsund, Svalbard [PDF]

, 1986
Polar bear hunting success on ringed seals in subnivean lairs and basking on the fast ice, was studied in Hornsund, Svalbard. A few bears were observed while actually hunting, but in most cases bear tracks were followed by snowmobile to determine the ...
Gjertz, Ian, Lydersen, Christian
core   +1 more source

Finite-size-effect on a very large length scale in NBT-based lead-free piezoelectrics [PDF]

Journal of Advanced Dielectrics, 2019
Na0.5Bi0.5TiO3-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer applications.
Anupam Mishra, Dipak Kumar Khatua, Gobinda Das Adhikary, Naveen Kumar, Uma Shankar, Rajeev Ranjan   +5 more
doaj   +1 more source