In this paper, a simple and general method based on the finite Markov chain imbedding technique is proposed to determine the exact conditional distributions of runs and patterns in a sequence of Bernoulli trials given the total number of successes. The idea is that given the total number of successes, the Bernoulli trials are viewed as random permutations. Then, we extend the result to multistate trials. The conditional distributions studied here lead to runs and patterns-type distribution-free tests whose applications are widespread. Two applications are considered. First, a distribution-free test for randomness is applied to rainfall data at Oxford from 1858 to 1952. The second application is to develop runs and patterns-type distribution-free control charts which can be used as Phase I and/or Phase II control charts. Numerical results for two commonly used runs-type statistics, the longest run and scan statistics, are also given.
As a large group of cells in a central nervous system, astrocytes have a great influence on ion and energy metabolism in a nervous system. Disorders of neuronal ion and energy metabolism caused by impaired astrocytes play a key role in the pathogenesis of epilepsy. This paper reviews the existing computational models of epileptogenesis resulting from impaired astrocytes and presents several open perspectives with regard to ion and energy metabolism-induced epileptogenesis in a neuron-astrocyte-capillary coupled model. 相似文献
A class of acceptor–donor–acceptor chromophoric small-molecule non-fullerene acceptors, 1–4, with difluoroboron(iii) β-diketonate (BF2bdk) as the electron-accepting moiety has been developed. Through the variation of the central donor unit and the modification on the peripheral substituents of the terminal BF2bdk acceptor unit, their photophysical and electrochemical properties have been systematically studied. Taking advantage of their low-lying lowest unoccupied molecular orbital energy levels (from −3.65 to −3.72 eV) and relatively high electron mobility (7.49 × 10−4 cm2 V−1 s−1), these BF2bdk-based compounds have been employed as non-fullerene acceptors in organic solar cells with maximum power conversion efficiencies of up to 4.31%. Moreover, bistable resistive memory characteristics with charge-trapping mechanisms have been demonstrated in these BF2bdk-based compounds. This work not only demonstrates for the first time the use of a boron(iii) β-diketonate unit in constructing non-fullerene acceptors, but also provides more insights into designing organic materials with multi-functional properties.Boron(iii) β-diketonates have been demonstrated to serve as multi-functional materials in NFA-based OPVs and organic resistive memories. 相似文献
In recent years, there is very intense worldwide research and development work on electron cyclotron resonance ion source (ECRIS). Remarkable progress represented by the third generation superconducting ECRIS has been made with regards of intense highly charged ion beam production such as >600 eμA Ar16+, >10 eμA Ar18+, and hundreds of enA He-like Kr34+. A low energy heavy ion platform named Low Energy heavy ion Accelerator Facility (LEAF) that features a next generation 45 GHz ECRIS, a 300 kV high voltage platform, a 0.5 MeV/u radio-frequency quadrupole, and several multidisciplinary experimental terminals is under construction at the Institute of Modern Physics (IMP). This paper will report on the recent progress with ECRIS dedicated to highly charged ions and the status of LEAF at IMP that will provide new opportunities for highly charged ion physics in the near future. 相似文献
Propagation dynamics of the cosh-Airy vortex(CAiV) beams in a chiral medium is investigated analytically with Huygens–Fresnel diffraction integral formula. The results show that the CAiV beams are split into the left circularly polarized vortex(LCPV) beams and the right circularly polarized vortex(RCPV) beams with different propagation trajectories in the chiral medium. We mainly investigate the effect of the cosh parameter on the propagation process of the CAiV beams.The propagation characteristics, including intensity distribution, propagation trajectory, peak intensity, main lobe's intensity, Poynting vector, and angular momentum are discussed in detail. We find that the cosh parameter affects the intensity distribution of the CAiV beams but not its propagation trajectory. As the cosh parameter increases, the distribution areas of the LCPV and RCPV beams become wider, and the side lobe's intensity and peak intensity become larger. Besides, the main lobe's intensity of the LCPV and RCPV beams increase with the increase of the cosh parameter at a farther propagation distance, which is confirmed by the variation trend of the Poynting vector. It is significant that we can vary the cosh parameter to control the intensity distribution, main lobe's intensity, and peak intensity of the CAiV beams without changing the propagation trajectory. Our results may provide some support for applications of the CAiV beams in optical micromanipulation. 相似文献
This paper presents the theory development and numerical implementation of a new gradient-deficient-based ANCF (Absolute Nodal Coordinate Formulation) model applied to perform the nonlinear dynamic analysis of elastic line structures subject to large stretching and deformation. The derivations of model equations, introduced numerical approaches, and result validations are the focuses of this study. Different from the traditional rod theory for small stretching consideration, the present model implements the line structures’ large elongation concepts into both the control mechanisms of constitutive formulations and equations of motion. The effect of external hydrodynamic forces on structures is also included in the model formulations. Based on the conservation of energy, the line model developed in this study covers the variation in strain and takes a full account of the bending effect with large stretching. A finite-element-based implicit scheme according to a modified Newmark-beta method is employed to solve the assembled system equations with unknown variables of nodal position vectors, their tangential derivatives, and strains. Selected cases with dynamic motions, such as nonlinear oscillation of a compound pendulum, free falling of a horizontal elastic beam in air with two different settings of gravity, free falling of a submerged horizontal tether with and without an attached concentrated mass, and a submerged vertical tether with a prescribed translational motion, are simulated to verify the developed model by comparing the results with analytical solutions and published experimental data and numerical results. It is found the present ANCF model, as noticed with good matched results with analytical solutions, measurements and other published solutions, is demonstrated to be able to provide converged and reasonably accurate predictions on the responses of line structures subject to large dynamic motions.
A facile and environmentally friendly approach has been developed to prepare yolk‐shell porous microspheres of calcium phosphate by using calcium L ‐lactate pentahydrate (CL) as the calcium source and adenosine 5′‐triphosphate disodium salt (ATP) as the phosphate source through the microwave‐assisted hydrothermal method. The effects of the concentration of CL, the microwave hydrothermal temperature, and the time on the morphology and crystal phase of the product are investigated. The possible formation mechanism of yolk‐shell porous microspheres of calcium phosphate is proposed. Hemoglobin from bovine red cells (Hb) and ibuprofen (IBU) are used to explore the application potential of yolk‐shell porous microspheres of calcium phosphate in protein/drug loading and delivery. The experimental results indicate that the as‐prepared yolk‐shell porous microspheres of calcium phosphate have relatively high protein/drug loading capacity, sustained protein/drug release, favorable pH‐responsive release behavior, and a high biocompatibility in the cytotoxicity test. Therefore, the yolk‐shell porous microspheres of calcium phosphate have promising applications in various biomedical fields such as protein/drug delivery. 相似文献