5,017 research outputs found

    Bis[μ-1,2-bis­(1,2,4-triazol-4-yl)ethane]bis­[diiodidozinc(II)]

    Get PDF
    In the title dinuclear complex, [Zn2I4(C6H8N6)2], two ZnII atoms are bridged by two 1,2-bis­(1,2,4-triazol-4-yl)ethane (btre) ligands, forming a centrosymmetric metallacycle. The coordination geometry of the ZnII ion is distorted tetra­hedral with the coordination sphere formed by two N atoms from the triazole rings of two symmetry-related btre ligands and two iodide ligands

    State-independent geometric quantum gates via nonadiabatic and noncyclic evolution

    Full text link
    Geometric phases are robust to local noises and the nonadiabatic ones can reduce the evolution time, thus nonadiabatic geometric gates have strong robustness and can approach high fidelity. However, the advantage of geometric phase has not being fully explored in previous investigations. Here, we propose a scheme for universal quantum gates with pure nonadiabatic and noncyclic geometric phases from smooth evolution paths. In our scheme, only geometric phase can be accumulated in a fast way, and thus it not only fully utilizes the local noise resistant property of geometric phase but also reduces the difficulty in experimental realization. Numerical results show that the implemented geometric gates have stronger robustness than dynamical gates and the geometric scheme with cyclic path. Furthermore, we propose to construct universal quantum gate on superconducting circuits, and the gate fidelity can be 99.97%99.97\% and 99.87%99.87\%, respectively. Therefore, these high-fidelity quantum gates are promising for large-scale fault-tolerant quantum computation

    Vertex-disjoint triangles in K1,t-free graphs with minimum degree at least t

    Get PDF
    AbstractA graph is said to be K1,t-free if it does not contain an induced subgraph isomorphic to K1,t. Let h(t,k) be the smallest integer m such that every K1,t-free graph of order greater than m and with minimum degree at least t contains k vertex-disjoint triangles. In this paper, we obtain a lower bound of h(t,k) by a constructive method. According to the lower bound, we totally disprove the conjecture raised by Hong Wang [H. Wang, Vertex-disjoint triangles in claw-free graphs with minimum degree at least three, Combinatorica 18 (1998) 441–447]. We also obtain an upper bound of h(t,k) which is related to Ramsey numbers R(3,t). In particular, we prove that h(4,k)=9(k−1) and h(5,k)=14(k−1)

    Advances in imaging research of age-related macular degeneration

    Get PDF
    Age-related macular degeneration(AMD)is the main cause of blindness in the people older than 50 years old. In recent years, following the improvement of imaging techniques in ophthalmology, the pathogenesis of the disease, the level of diagnosis and efficacy evaluation ability greatly improved. In this paper, we reviewed and discussed the recent advancement on imaging research of age-relate d macular degeneration

    Numerical and physical simulation of rapid microstructural evolution of gas atomised Ni superalloy powders

    Get PDF
    The rapid microstructural evolution of gas atomised Ni superalloy powder compacts over timescales of a few seconds was studied using a Gleeble 3500 thermomechanical simulator, finite element based numerical model and electron microscopy. The study found that the microstructural changes were governed by the characteristic temperatures of the alloy. At a temperature below the γ' solvus, the powders maintained dendritic structures. Above the γ' solvus temperature but in the solid-state, rapid grain spheroidisation and coarsening occurred, although the fine-scale microstructures were largely retained. Once the incipient melting temperature of the alloy was exceeded, microstructural change was rapid, and when the temperature was increased into the solid + liquid state, the powder compact partially melted and then re-solidified with no trace of the original structures, despite the fast timescales. The study reveals the relationship between short, severe thermal excursions and microstructural evolution in powder processed components, and gives guidance on the upper limit of temperature and time for powder-based processes if desirable fine-scale features of powders are to be preserved

    Decreased Triple Network Connectivity in Patients with Recent Onset Post-Traumatic Stress Disorder after a Single Prolonged Trauma Exposure

    Full text link
    The triple network model provides a common framework for understanding affective and neurocognitive dysfunctions across multiple disorders, including central executive network (CEN), default mode network (DMN), and salience network (SN). Considering the effect of traumatic experience on post-traumatic stress disorder (PTSD), this study aims to explore the alteration of triple network connectivity in a specific PTSD induced by a single prolonged trauma exposure. With an arterial spin labeling sequence, three networks were first identified using independent component analysis among 10 PTSD patients and 10 healthy survivors, who experienced the same coal mining flood disaster. Then, the triple network connectivity was analyzed and compared between PTSD and non-PTSD groups. In PTSD patients, decreased connectivity was identified in left middle frontal gyrus of CEN, left precuneus and bilateral superior frontal gyrus of DMN, and right anterior insula of SN. The decreased connectivity in left middle frontal gyrus of CEN was associated with clinical severity. Furthermore, no significant connection of SN with CEN and DMN was found in PTSD patients. The decreased triple network connectivity was found in this study, which not only supports the triple network model, but also suggests a possible neurobiological mechanism for cognitive dysfunction of this type of PTSD

    Design and Synthesis of Novel Anticancer Peptide Nanoparticles

    Get PDF
    Cancer has now become a common disease affecting human health. Existing cancer treatment drugs can no longer meet the growing needs of cancer patients, and the emergence of anticancer drug resistance has exacerbated this phenomenon. By designing and synthesizing new anticancer peptide nanoparticles and studying their anticancer effects, new strategies for cancer treatment may be obtained. Novel anticancer peptides are synthesized by adding basic amino acids and solid-phase synthesis technology, and their structural information is determined by mass spectrometry. Nanoparticles of anticancer peptide were synthesized by nano-self-assembly technology. Two novel anticancer peptides exhibited anticancer activity, one of which was assembled into nanoparticles. The theoretical isoelectric points of the modified SZG3 and SZG5 are all greater than physiological pH, and will be positively charged under physiological conditions. The estimated half-life of SZG3 and SZG5 is significantly extended (30h), which is beneficial to increase the efficacy and reduce toxic and side effects. SZG3 and SZG5 have a good inhibitory effect on tumor cells and have low toxicity to normal cells. Keywords: anticancer peptide, study, design, cancer, nanoparticles&nbsp

    Laser modulation simulation of micro-crack morphology evolution during chemical etching

    Get PDF
    Subsurface micro-cracks will be generated during the grinding and polishing processes of optical components. Micro-cracks have a modulation effect on the laser, thereby reducing the laser damage threshold. The FDTD method is used to simulate the light intensity distribution modulated by micro-crack. By comparing the simulation results of radial crack, parabolic crack and elliptic crack, the modulation mechanism of micro-crack is revealed. The results show that for the crack with the same width and depth, light intensity enhancement factor (LIEF) modulated by radial crack on the rear surface and parabolic crack on the front surface is the largest; LIEF modulated by elliptical crack on the rear surface and radial crack on the front surface is the smallest. In addition, when the crack width-depth ratio is the same, the larger the depth, the higher the LIEF. As the width-depth ratio increases, the LIEF value increases firstly, then decreases, and finally approaches a stable value.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
    corecore