6,056 research outputs found
Tris(2-methylÂpiperidinium) tetraÂchloridoÂferrate dichloride
The asymmetric unit of the title salt, (C6H14N)3[FeCl4]Cl2, consists of a tetraÂhedral tetraÂchloroÂferrate anion, three independent 2-methylÂpiperidinium cations and two chloride ions. All the piperidine rings adopt chair conformations. In the crystal, the organic cations and the free chloride anions are linked into chains parallel to the a axis by N—H⋯Cl hydrogen bonds
A comment on "Ab initio calculations of pressure-dependence of high-order elastic constants using finite deformations approach" by I. Mosyagin, A.V. Lugovskoy, O.M. Krasilnikov, Yu.Kh. Vekilov, S.I. Simak and I.A. Abrikosov
Recently, I. Mosyagin, A.V. Lugovskoy, O.M. Krasilnikov, Yu.Kh. Vekilov, S.I.
Simak and I.A. Abrikosov in the paper: "Ab initio calculations of
pressure-dependence of high-order elastic constants using finite deformations
approach"[Computer Physics Communications 220 (2017) 2030] presented a
description of a technique for ab initio calculations of the pressure
dependence of second- and third-order elastic constants. Unfortunately, the
work contains serious and fundamental flaws in the field of finite-deformation
solid mechanics.Comment: 3 pages, 0 figure
LogisticLDA: Regularizing Latent Dirichlet Allocation by Logistic Regression
PACLIC 23 / City University of Hong Kong / 3-5 December 200
Influence of Spartina alterniflora invasion stages on macrobenthic communities on a tidal flat in Wenzhou Bay, China
Muitos habitats costeiros vêm sendo alterados substancialmente pela invasão de Spartina alterniflora no leste da China. Em 2007, em uma planÃcie de maré situada em Wenzhou Bay, foram analisadas riqueza de espécies, densidade e diversidade da macrofauna bêntica em relação a diferentes estágios da invasão da gramÃnea e à estação do ano. Para as medidas de diversidade foram usados os Ãndices de Margalef (R) e de Shannon (H'). Foram detectados efeitos significativos do estágio de invasão e época do ano sobre a macrofauna. As comunidades macrofaunais foram mais complexas nas manchas onde a invasão de S. alterniflora estava no seu inÃcio, quando considerados os locais onde as manchas estavam em estágios mais avançados. Através das análises de agrupamento e ordenação as comunidades puderam ser classificadas pelo tipo de habitat formado em cada estágio de invasão da Spartina. Os resultados indicaram que a biodiversidade aumentou no estágio de invasão inicial (idade de invasão de 1 a 2 anos), mas diminuiu gradativamente com os estágios intermediário (idade de invasão de 3 a 4 anos) e completo (idade de invasão de 5 a 6 anos), mostrando assim o efeito deletério de S. alterniflora sobre a estrutura da macrofauna presente no local.Many coastal habitats in eastern China are being substantially altered by the invasion of Spartina alterniflora. The species richness, density, Margalef's diversity index (R) and Shannon's diversity index (H') of macrobenthic communities on a tidal flat in Wenzhou Bay, China, were analyzed with the factors of invasion stage and season, in 2007. A significant effect of invasion stage, season, and the interaction between them on communities was detected. The macrobenthic community was more complex in the patch of initial S. alterniflora invasion than in the patches of some other invasion stages. Macrobenthic communities were classified by cluster and ordination in accordance with the habitat character of the S. alterniflora invasion stage. Our research demonstrated that the S. alterniflora invasion stage affected the macrobenthic communities significantly. The results indicated that biodiversity increased in the initial stage of invasion (invasion age 1-2 years) and then decreased in the stage of invasion underway (invasion age 3-4 years) and in the stage of invasion completed (invasion age 5-6 years); this phenomenon was related to the change in the S. alterniflora canopy which accompanied the invasion stages
Experimental Free-Space Distribution of Entangled Photon Pairs over a Noisy Ground Atmosphere of 13km
We report free-space distribution of entangled photon pairs over a noisy
ground atmosphere of 13km. It is shown that the desired entanglement can still
survive after the two entangled photons have passed through the noisy ground
atmosphere. This is confirmed by observing a space-like separated violation of
Bell inequality of . On this basis, we exploit the distributed
entangled photon source to demonstrate the BB84 quantum cryptography scheme.
The distribution distance of entangled photon pairs achieved in the experiment
is for the first time well beyond the effective thickness of the aerosphere,
hence presenting a significant step towards satellite-based global quantum
communication.Comment: 4 pages, 3 figure
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