Possible room temperature ferromagnetism of Li-doped anatase TiO2: A first-principles study

The electronic structures and magnetic properties in substitutionally lithium-doped anatase TiO₂ (Li-TiO₂) have been investigated by density functional calculations. We found that while Li itself is nonmagnetic, it generates holes residing in O 2pπ orbitals that lead to magnetic moments in TiO₂. The magnetic moments are delocalized but inhomogeneous distributed in the lattice with long rang ferromagnetic interactions among them. The inhomogeneous distribution of the magnetic moments and the specific crystal symmetry results in distance as well as directional dependence of the ferromagnetism stability of the Li-TiO₂ system. Our calculations suggest Li-TiO₂ to be potential spintronics material.     

A mechanism for radon decline prior to the 1978 Izu-Oshima-Kinkai earthquake in Japan

Precursory changes in the radon concentration of groundwater were observed by Wakita et al. (1980) prior to the 1978 Izu-Oshima-Kinkai earthquake of magnitude 7.0. Mechanisms for interpreting the anomalous radon decrease are examined in this paper. The SKE-1 well is situated in a volcanic-rock fractured aquifer of limited recharge. Given these geological conditions, the dilation of brittle rock mass occurred at a rate faster than the recharge of groundwater and gas saturation developed in newly created cracks preceding the earthquake. Radon volatilization into the gas phase can explain the anomalous decrease of radon precursory to the 1978 earthquake. To support the hypothesis, vapor–liquid two-phase radon-partitioning experiments were conducted at formation temperature (14 °C) using formation water from the SKE-1 well. Experimental data indicated that the decrease in radon concentration from 483 ± 3 count/min to 439 ± 7 count/min required a gas saturation of 2.35% developed in rock cracks through the dilatancy process.     

Quantum spins in Mackay icosahedral gold nanoparticles

We report on the direct observation of the intrinsic magnetization behavior of Mackay icosahedral Au nanoparticles. The spin arrangements in 3.5-nm icosahedral Au particles are found to be ferrimagnetic-like, where the core and surface moments point in opposite directions, with a net spontaneous magnetic moment of 16 μ_B per particle. The unpaired spins behave as J = 1/2 quantum spins. The average level separation is found to be a factor of ~1.53 larger than that estimated according to the Kubo formula for spherical Au particles. This reflects the fact that there are considerably fewer atoms packed in a particle with an icosahedral geometry than with a spherical one.     

Sleep triggered by an immune response in <Emphasis Type="Italic">Drosophila</Emphasis> is regulated by the circadian clock and requires the NFκB Relish

Background  

Immune challenge impacts behavior in many species. In mammals, this adaptive behavior is often manifested as an increase in sleep. Sleep has therefore been proposed to benefit the host by enhancing immune function and thereby overcome the challenge. To facilitate genetic studies on the relationship between sleep and immune function, we characterized the effect of the immune response on sleep in Drosophila melanogaster. Behavioral features of sleep as well as the innate immune response signaling pathways are well characterized in flies and are highly conserved in mammals.     

Enhancement in hole-injection efficiency of blue InGaN light-emitting diodes from reduced polarization by some specific designs for the electron blocking layer

Some specific designs on the electron blocking layer (EBL) of blue InGaN LEDs are investigated numerically in order to improve the hole injection efficiency without losing the blocking capability of electrons. Simulation results show that polarization-induced downward band bending is mitigated in these redesigned EBLs and, hence, the hole injection efficiency increases markedly. The optical performance and efficiency droop are also improved, especially under the situation of high current injection.     

Nucleosides XII.1 Synthesis of 5‐Modified Isoguanosines and Reinvestigation of 5′‐Deoxy‐N3,5′‐cycloisoguanosine

Isoguanosine ( 3 ) underwent a coupling reaction with diaryl disulfides in the presence of tri‐n‐butylphosphine when its 6‐amino group was protected by N,N‐dimethylaminomethylidene. The synthesis of 5′‐deoxy‐N³,5′‐cycloisoguanosine ( 6 ) and its 2′,3′‐O‐isopropylidene derivative ( 11 ) were accomplished in excellent yields from isoguanosines ( 3 & 10 ) in the presence of triphenylphospine and carbon tetrachloride in pyridine. Chlorination at the 5′‐position of isoguanosine ( 3 ) with thionyl chloride followed by the aqueous base‐promoted cyclization afforded the same product 6 . The structures were elucidated by spectroscopic analysis including IR, UV, 1‐D and 2‐D NMR.     

台湾的植物生物多样性及其特点之探讨

在物种多样性、生态系统多样性和遗传多样性三个层面上，探讨了台湾植物生物多样性的现状；在分析台湾植物生物多样性及与周边地区比较的基础上，从多个方面对其特点作了探讨，并对台湾与大陆在植物生物多样性方面的亲缘性作了阐明。     

Molecularly Imprinted Electrochemical Sensors

In this review, the applications of molecularly imprinted polymer (MIP) materials in the area of electrochemical sensors have been explored. The designs of the MIPs containing different polymers, their preparation and their immobilization on the transducer surface have been discussed. Further, the employment of various transducers containing the MIPs based on different electrochemical techniques for determining analytes has been assessed. In addition, the general protocols for getting the electrochemical signal based on the binding ability of analyte with the MIPs have been given. The review ends with describing scope and limitations of the above electrochemical based MIP sensors.     

para‐Quinodimethane‐Bridged Perylene Dimers and Pericondensed Quaterrylenes: The Effect of the Fusion Mode on the Ground States and Physical Properties

Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para‐quinodimethane (p‐QDM)‐bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7 , were synthesized. Their ground‐state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p‐QDM‐bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (?2.97 kcal mol^?1), whereas the antiaromatic s‐indacene‐bridged N‐annulated perylene dimer 5 exists as a closed‐shell quinoid with an obvious intramolecular charge‐transfer character. Both of these dimers showed shorter singlet excited‐state lifetimes, larger two‐photon‐absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7 , respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.     

Numerical Ranges of Radial Toeplitz Operators on Bergman Space

A Toeplitz operator T_fT_\phi with symbol f\phi in L^￥(\mathbbD)L^{\infty}({\mathbb{D}}) on the Bergman space A²(\mathbbD)A^{2}({\mathbb{D}}), where \mathbbD\mathbb{D} denotes the open unit disc, is radial if f(z) = f(|z|)\phi(z) = \phi(|z|) a.e. on \mathbbD\mathbb{D}. In this paper, we consider the numerical ranges of such operators. It is shown that all finite line segments, convex hulls of analytic images of \mathbbD\mathbb{D} and closed convex polygonal regions in the plane are the numerical ranges of radial Toeplitz operators. On the other hand, Toeplitz operators T_fT_\phi with f\phi harmonic on \mathbbD\mathbb{D} and continuous on [`(\mathbbD)]{\overline{\mathbb{D}}} and radial Toeplitz operators are convexoid, but certain compact quasinilpotent Toeplitz operators are not.