Observation of topological transition of Fermi surface from a spindle-torus to a torus in large bulk Rashba spin-split BiTeCl

The recently observed large Rashba-type spin splitting in the BiTeX (X = I, Br, Cl) bulk states due to the absence of inversion asymmetry and large charge polarity enables observation of the transition in Fermi surface topology from spindle-torus to torus with varying the carrier density. These BiTeX systems with high spin-orbit energy scales offer an ideal platform for achieving practical spintronic applications and realizing non-trivial phenomena such as topological superconductivity and Majorana fermions. Here we use Shubnikov-de Haas oscillations to investigate the electronic structure of the bulk conduction band of BiTeCl single crystals with different carrier densities. We observe the topological transition of the Fermi surface (FS) from a spindle-torus to a torus. The Landau level fan diagram reveals the expected non-trivial {\pi} Berry phase for both the inner and outer FSs. Angle-dependent oscillation measurements reveal three-dimensional FS topology when the Fermi level lies in the vicinity of the Dirac point. All the observations are consistent with large Rashba spin-orbit splitting in the bulk conduction band.Comment: 28 pages, supplementary informatio

Experimentally obtaining the Likeness of Two Unknown Quantum States on an NMR Quantum Information Processor

Recently quantum states discrimination has been frequently studied. In this paper we study them from the other way round, the likeness of two quantum states. The fidelity is used to describe the likeness of two quantum states. Then we presented a scheme to obtain the fidelity of two unknown qubits directly from the integral area of the spectra of the assistant qubit(spin) on an NMR Quantum Information Processor. Finally we demonstrated the scheme on a three-qubit quantum information processor. The experimental data are consistent with the theoretical expectation with an average error of 0.05, which confirms the scheme.Comment: 3 pages, 4 figure

Mollusc aquaculture homogenizes intertidal soft-sediment communities along the 18,400 km long coastline of China

Abstract Aim Molluscs are important grazers, filter and deposit feeders, scavengers and predators, which in turn are food for shorebirds, fish and people. Some species, targeted as human food, have been cultured along the Chinese coast for hundreds of years. To examine whether aquacultural practices have meanwhile affected biodiversity gradients, we measured mollusc community structure along the coast of China in habitats which are intensively used by humans. Location Chinese coast. Methods We sampled 21 intertidal sites spanning 20 latitudinal degrees and 18,400 km of coastline. We assessed alpha diversity to verify whether mollusc communities exhibit the expected biodiversity gradient with latitude and beta diversity gradients with distance. To examine whether human activities such as transportation and culturing could have affected these patterns, we distinguished commercial from non-commercial mollusc species and compared the differences in distribution, density, alpha diversity and beta diversity. Results We found non-commercial species showed the expected biodiversity gradients. Commercial species (a) dominated the intertidal mollusc communities at 19 of the 21 sites and compared with non-commercial species, (b) exhibited wider geographical distributions, (c) showed no significant change in Bray-Curtis index (abundance-based beta diversity) with either geographical or climatic distance, (d) exhibited lower average dissimilarities and (e) did not show a decrease in species richness and Shannon diversity with latitude. Combining all species, trends were the same as for the commercial species. Main conclusions A few cultured species dominated the intertidal mollusc communities in high densities along the Chinese coastline, taking over the ecological roles of the native species but not driving them extinct. In this way, aquacultural practices have exerted a homogenizing influence strong enough to erase basic biodiversity gradients. Since molluscs are food for the growing human population and the shrinking populations of migratory animals, coastal planning and management of both intertidal habitats and the exploitative activities employed need to incorporate these dimensions

The association between post-stroke depression, aphasia, and physical independence in stroke patients at 3-month follow-up

Objective: Few studies have examined the association between post-stroke depression (PSD), aphasia, and physical independence in Chinese patients. This study investigated the above association in stroke patients in China at 3-month follow-up. Methods: Altogether 270 patients within 14 days after ischemic stroke were recruited and followed up at 3 months. PSD, aphasia, and physical functional status were measured using the Stroke Aphasia Depression Questionnaire (SADQ), Western Aphasia Battery (WAB), and modified Rankin Scale (mRS), respectively. Patients with mRS total score \u3e2 were considered as having “physical dependence.” Results: Out of 248 patients at 3-month follow up, 119 (48%) were rated as having physical dependence. Multiple logistic regression analyses revealed that female (p = 0.04; OR = 2.2; 95% CI: 1.0–5.1), more severe stroke at admission (p \u3c 0.01; OR = 1.4; 95% CI: 1.3–1.5), and more severe PSD at 3 months (p = 0.01; OR = 1.05; 95% CI: 1.01–1.1) were independently associated with physical dependence at 3 months. Conclusions: Greater PSD and stroke severity were independently associated with physical dependence at 3months after stroke. Aphasia was also associated with physical dependence but the relationship was not significant. Early and effective depression screening, treatment and stroke rehabilitation appear to be important to improve the physical outcome and reduce the burden of stroke survivors

A supramolecular recyclable catalyst for aqueous Suzuki-Miyaura coupling

© The Royal Society of Chemistry 2015. A water-soluble, supramolecular catalytic system has been designed based on inclusion complexation between a hydrophobic palladium(ii)-dipyrazole complex bearing an adamantyl (Ad) molecular recognition moiety and a complementary, hydrophilic β-cyclodextrin (β-CD) derivative. The single-crystal molecular structure of the Pd(ii) complex was determined and its host-guest inclusion complexation with heptakis(2,6-di-O-methyl)-β-CD (dmβ-CD) in an aqueous medium was confirmed by 2D NOESY 1H NMR spectroscopy. The catalyst showed high activity for Suzuki-Miyaura coupling of hydrophilic aryl bromides with aryl boronic acids in aqueous organic solvents. In the presence of n-Bu4NBr as a stabilizer, the catalyst-containing reaction solution can be recycled and reused multiple times to catalyze the coupling reaction of fresh substrates once the product has been removed by centrifugation. This work demonstrates a supramolecular complex approach, non-covalently modifying a water insoluble metal complex to provide a water-soluble inclusion system to serve as a recyclable catalyst for potential application in green chemical synthesis. This journal isLink_to_subscribed_fulltex

The Association Between Post-stroke Depression, Aphasia, and Physical Independence in Stroke Patients at 3-Month Follow-Up

Objective: Few studies have examined the association between post-stroke depression (PSD), aphasia, and physical independence in Chinese patients. This study investigated the above association in stroke patients in China at 3-month follow-up.Methods: Altogether 270 patients within 14 days after ischemic stroke were recruited and followed up at 3 months. PSD, aphasia, and physical functional status were measured using the Stroke Aphasia Depression Questionnaire (SADQ), Western Aphasia Battery (WAB), and modified Rankin Scale (mRS), respectively. Patients with mRS total score >2 were considered as having “physical dependence.”Results: Out of 248 patients at 3-month follow up, 119 (48%) were rated as having physical dependence. Multiple logistic regression analyses revealed that female (p = 0.04; OR = 2.2; 95% CI: 1.0–5.1), more severe stroke at admission (p < 0.01; OR = 1.4; 95% CI: 1.3–1.5), and more severe PSD at 3 months (p = 0.01; OR = 1.05; 95% CI: 1.01–1.1) were independently associated with physical dependence at 3 months.Conclusions: Greater PSD and stroke severity were independently associated with physical dependence at 3 months after stroke. Aphasia was also associated with physical dependence but the relationship was not significant. Early and effective depression screening, treatment and stroke rehabilitation appear to be important to improve the physical outcome and reduce the burden of stroke survivors

Application of functionalized nanofluid in thermosyphon

A water-based functionalized nanofluid was made by surface functionalizing the ordinary silica nanoparticles. The functionalized nanofluid can keep long-term stability. and no sedimentation was observed. The functionalized nanofluid as the working fluid is applied in a thermosyphon to understand the effect of this special nanofluid on the thermal performance of the thermosyphon. The experiment was carried out under steady operating pressures. The same work was also explored for traditional nanofluid (consisting of water and the same silica nanoparticles without functionalization) for comparison. Results indicate that a porous deposition layer exists on the heated surface of the evaporator during the operating process using traditional nanofluid; however, no coating layer exists for functionalized nanofluid. Functionalized nanofluid can enhance the evaporating heat transfer coefficient, while it has generally no effect on the maximum heat flux. Traditional nanofluid deteriorates the evaporating heat transfer coefficient but enhances the maximum heat flux. The existence of the deposition layer affects mainly the thermal performance, and no meaningful nanofluid effect is found in the present study