Quantum correlation measure in arbitrary bipartite systems

A definition of quantum correlation is presented for an arbitrary bipartite quantum state based on the skew information. This definition not only inherits the good properties of skew information such as the contractivity and so on, but also is effective and almost analytically calculated for any bipartite quantum states. We also reveal the relation between our measure and quantum metrology. As applications, we give the exact expressions of quantum correlation for many states, which provides a direct support for our result.Comment: 6 pages, 2 figures. Comments are welcom

cDNA-AFLP analysis of gene expression differences between the flower bud and sprout-shoot apical meristem of Angelica sinensis (Oliv.) Diels

Angelica sinensis (Oliv.) Diels (Umbelliferae) is a well-known medicinal plant mainly distributed in Gansu Province of China. Its local and global demand is significant because of its food and medicinal applications. However, the early bolting rate of Angelica sinensis (Oliv.) Diels reaches 20%–60%, which seriously affects its food and medicinal qualities. Thus, differences in gene expression between the flower bud and sprout-shoot apical meristem underwent analysis, by means of cDNA-amplified restriction fragment length polymorphism, to better understand the flowering mechanism. 64 primer sets, each of which amplified to 60 transcript-derived fragments (TDFs), were used. Among these TDFs, 26 were expressed specifically in the flower bud. After cloning and sequencing, 32 distinct sequences were obtained from these 26 TDFs, and 25 were found with homologous sequences in databases. Confirmation of differential expression of 13 sequences was obtained by semi-quantitative RT-PCR, their showing higher expression levels in flower buds. These homologous sequences encode transposable elements, pentatricopeptide repeat-containing proteins, DNA-binding transcription factors, zinc finger (B-box type) family proteins, NADP-dependent sorbitol 6-phosphate dehydrogenase (S6PDH), amongst others

2,10-Dibromo-6,6-dimethyl­dibenzo[d,f][1,3]dioxepine

In the crystal structure of the title compound, C15H12Br2O2, which was synthesized from 2,10-dibromo-2,2′-dihydroxy­biphenyl and 2,2-dimethoxy­propane, the aromatic rings are twisted by 35 (1)°. The heterocyclic ring exhibits a twisted conformation

Temperature Dependent Empirical Pseudopotential Theory For Self-Assembled Quantum Dots

We develop a temperature dependent empirical pseudopotential theory to study the electronic and optical properties of self-assembled quantum dots (QDs) at finite temperature. The theory takes the effects of both lattice expansion and lattice vibration into account. We apply the theory to the InAs/GaAs QDs. For the unstrained InAs/GaAs heterostructure, the conduction band offset increases whereas the valence band offset decreases with increasing of the temperature, and there is a type-I to type-II transition at approximately 135 K. Yet, for InAs/GaAs QDs, the holes are still localized in the QDs even at room temperature, because the large lattice mismatch between InAs and GaAs greatly enhances the valence band offset. The single particle energy levels in the QDs show strong temperature dependence due to the change of confinement potentials. Because of the changes of the band offsets, the electron wave functions confined in QDs increase by about 1 - 5%, whereas the hole wave functions decrease by about 30 - 40% when the temperature increases from 0 to 300 K. The calculated recombination energies of exciton, biexciton and charged excitons show red shifts with increasing of the temperature, which are in excellent agreement with available experimental data

Poly[[[diaqua­cobalt(II)]-bis­[μ2-1,1′-(butane-1,4-di­yl)diimidazole-κ2 N 3:N 3′]] dinitrate]

In the title compound, {[Co(C10H14N4)2(H2O)2](NO3)2}n, the CoII ion lies on an inversion center and is six-coordinated in an octa­hedral environment by four N atoms from four different 1,1′-butane-1,4-diyldiimidazole ligands and two O atoms from the two water mol­ecules. The CoII atoms are bridged by ligands, generating a two-dimensional (4,4)-network. Adjacent fishnet planes are linked to the nitrate anions via O—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular structure

2-Bromo-2-(5-bromo-1H-1,2,4-triazol-1-yl)-1-(2,4-difluoro­phen­yl)ethanone

In the title compound, C10H5Br2F2N3O, the mean planes of the benzene and triazole rings form a dihedral angle of 84.86 (2)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into extended chains propagating along the c axis