THE ESTABLISHMENT OF MATHEMATICAL MODEL OF THE TAKE-OFF SPEED OF AERIALS OF FREESTYLE SKIING

The take-off speed of freestyle skiing aerials is one of the key factors which can decide the success. However, the take-off speed depends on snow quality, circumstance condition, in-run slope angle, in-run distance, air resistance and skiers’ action. By using sports biomechanics, mathematical model and numerical simulation method and combining theory with experiment, this study sets up a mathematical model of outside circumstance and skiers’ self-adjustment, simulates the changes of inside and outside stress in each stage of sliding, calculates the parameters intuitively and then forms into speed values. The setup of this model can provide scientific guidance for ensuring necessary take-off speed for specific actions

Comparison of long-term radial artery occlusion following trans-radial coronary intervention using 6-french versus 7-french sheaths

Background: The aim of this study was to explore the impact of 6-Fr and 7-Fr sheaths on the incidenceof long-term radial artery occlusion (RAO) after trans-radial coronary intervention (TRI).Methods: From September 2013 to January 2016, patients with ischemic heart disease includingacute myocardial infarction and true bifurcation lesions were randomly assigned to 6-Fr group and7-Fr group immediately after coronary angiography in a 1:1 ratio. The radial artery diameters wereobserved by ultrasound examination one day prior to TRI as well as at 30 days and 1 year after TRI.The primary endpoint was the incidence of RAO at 1-year after TRI. The secondary endpoints were theincidence of local vascular complications during hospitalization and changes of radial artery diameterswithin 1-year after TRI between the two groups. Additionally, multivariate logistic regression analysiswas used to explore potential factors related to the incidence of long-term RAO after TRI.Results: A total of 214 patients were enrolled and randomly assigned to 6-Fr group (n = 105) or7-Fr group (n = 109). There was no significant difference in the incidence of RAO at 1-year after TRI(8.57% vs. 12.84%, p = 0.313). Moreover, no significant difference was observed in the incidence of localvascular complications during hospitalization (20% vs. 24.77%, p = 0.403). After 1-year follow-up,no significant difference was found in radial artery diameters (2.63 ± 0.31 mm vs. 2.64 ± 0.27 mm,p = 0.802). Multivariate logistic analysis revealed that repeated TRI was an independent risk factor oflong-term RAO 1 year after TRI (OR = 10.316, 95% CI 2.928–36.351, p = 0.001).Conclusions: Compared to 6-Fr sheath, 7-Fr sheath did not increase short-term or long-term incidenceof RAO after TRI

In vitro propagation of katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc), an endangered plant in China

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) is a long-lived, deciduous, wind-pollinated tree with dimorphic leaves. It is valued as an ornamental or a shade tree for landscape and a commercially valuable tree. Conventional propagation through seeds and cutting is not sufficient to satisfy the progressive demand. There is an exigent need to develop protocols for rapid propagation of katsura trees. This study reports an in vitro propogation of the tree. The work focused on assessing the effects of basal medium, plant growth regulators (PGRs) combination on shoot and root proliferation. Nodal sections of young shoots were used as explants. Shoot initiation, and shoot and root proliferation were carried out on basal medium and PGRs combination. The optimal response of shoot initiation was observed in woody plant medium (WPM) supplemented with 1.0 mg L−1BA and 0.01 mg L−1IBA (indole-3-butyric acid) and the percentage of shoot initiation was up to 91.66%. For proliferation of micropropagated shoots, three orthogonal designs were carried out. The result shows that the highest proliferation coefficient (4.83) was obtained in the medium containing 1.0 mg L−1 BA and 0.05 mg L−1 NAA. With the application of benzyladenine (BA) and naphthalene acetic acid (NAA), emerald green and vigorous shoots were observed. Shoots about 2.0 cm long with 4 to 6 leaves were excised and transferred to root propagation media. When the concentration of NAA was 0.5 mg L−1, the rooting percentage, mean number and mean length of roots were the highest, reaching 75% and 3.1 and 2.1 cm respectively. This efficient plant regeneration system would be helpful for genetic improvement through future conservation and biotechnology research.Keywords: Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc), shoot initiation, shoot propagation, root propagatio

Community-Aware Efficient Graph Contrastive Learning via Personalized Self-Training

In recent years, graph contrastive learning (GCL) has emerged as one of the optimal solutions for various supervised tasks at the node level. However, for unsupervised and structure-related tasks such as community detection, current GCL algorithms face difficulties in acquiring the necessary community-level information, resulting in poor performance. In addition, general contrastive learning algorithms improve the performance of downstream tasks by increasing the number of negative samples, which leads to severe class collision and unfairness of community detection. To address above issues, we propose a novel Community-aware Efficient Graph Contrastive Learning Framework (CEGCL) to jointly learn community partition and node representations in an end-to-end manner. Specifically, we first design a personalized self-training (PeST) strategy for unsupervised scenarios, which enables our model to capture precise community-level personalized information in a graph. With the benefit of the PeST, we alleviate class collision and unfairness without sacrificing the overall model performance. Furthermore, the aligned graph clustering (AlGC) is employed to obtain the community partition. In this module, we align the clustering space of our downstream task with that in PeST to achieve more consistent node embeddings. Finally, we demonstrate the effectiveness of our model for community detection both theoretically and experimentally. Extensive experimental results also show that our CEGCL exhibits state-of-the-art performance on three benchmark datasets with different scales.Comment: 12 pages, 7 figure

Engineering ferroelectricity in monoclinic hafnia

Ferroelectricity in the complementary metal-oxide semiconductor (CMOS)-compatible hafnia (HfO$_2$) is crucial for the fabrication of high-integration nonvolatile memory devices. However, the capture of ferroelectricity in HfO$_2$ requires the stabilization of thermodynamically-metastable orthorhombic or rhombohedral phases, which entails the introduction of defects (e.g., dopants and vacancies) and pays the price of crystal imperfections, causing unpleasant wake-up and fatigue effects. Here, we report a theoretical strategy on the realization of robust ferroelectricity in HfO$_2$-based ferroelectrics by designing a series of epitaxial (HfO$_2$)$_1$/(CeO$_2$)$_1$ superlattices. The advantages of the designated ferroelectric superlattices are defects free, and most importantly, on the base of the thermodynamically stable monoclinic phase of HfO$_2$. Consequently, this allows the creation of superior ferroelectric properties with an electric polarization $>$25 $\mu$C/cm$^2$ and an ultralow polarization-switching energy barrier at $\sim$2.5 meV/atom. Our work may open an entirely new route towards the fabrication of high-performance HfO$_2$ based ferroelectric devices

Multi-objective Black Widow Algorithm Guided by Competitive Mechanism and Pheromone Mechanism

Black widow optimization algorithm (BWOA) is a swarm intelligence optimization algorithm, which has the advantages of fast convergence and high precision. However, the update strategy adopted by BWOA is too simple, and it is easy to fall into the local optimal solution. Moreover, the search ability in multi-dimensional space is lacking, the population structure is single, and the convergence and diversity of the algorithm need to be improved.  In order to improve the comprehensive performance of BWOA and make it applicable to multi-objective optimization problems, this paper proposes a multi-objective black widow optimization algorithm (MBWOA) guided by a competition mechanism and an improved pheromone mechanism. MBWOA adopts the method of dynamic allocation of populations, which divides the populations into two in the iterative process and uses different competition mechanisms to enhance the diversity of the populations in the iterative process and improve the convergence of the algorithm. At the same time, it uses the improved pheromone mechanism to guide offspring individuals that have gone through the competition mechanism to optimize in the direction of population gap, improve the distribution of population, and enhance the convergence ability of the algorithm. Using MBWOA and four comparison algorithms to conduct comparative experiments on three indicators of IGD, HV and Spread respectively, the results show that MBWOA has better convergence accuracy, convergence speed and diversity. Finally, the effectiveness of the used mechanism is confirmed by the experiments of MBWOA and the comparison algorithms on three indicators

Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s

Identity between pre-miR166s in soybean. (TIF 5906 kb

High-pressure Phase Stability and Superconductivity of Pnictogen Hydrides and Chemical Trends for Compressed Hydrides

The recent breakthrough discovery of unprecedentedly high temperature superconductivity of 203 K in compressed sulfur hydrides has stimulated significant interest in finding new hydrogen-containing superconductors and elucidating the physical and chemical principles that govern these materials and their superconductivity. Here we report the prediction of high temperature superconductivity in the family of pnictogen hydrides using first principles calculations in combination with global optimization structure searching methods. The hitherto unknown high-pressure phase diagrams of binary hydrides formed by the pnictogens of phosphorus, arsenic and antimony are explored, stable structures are identified and their electronic, vibrational and superconducting properties are investigated. We predict that SbH_4 and AsH_8 are high-temperature superconductors at megabar pressures, with critical temperatures in excess of 100 K. The highly symmetrical hexagonal SbH_4 phase is predicted to be stabilized above about 150 GPa, which is readily achievable in diamond anvil cell experiments. We find that all phosphorus hydrides are metastable with respect to decomposition into the elements within the pressure range studied. Trends based on our results and data in the literature reveal a connection between the high-pressure behaviors and ambient-pressure chemical quantities which provides insight into understanding which elements may form hydrogen-rich high-temperature superconducting phases at high pressures.The authors thank Eva Zurek for sharing structure data for iodine hydride. The work at Jilin Univ. is supported by the funding of National Natural Science Foundation of China under Grant Nos. 11274136 and 11534003, 2012 Changjiang Scholar of Ministry of Education and the Postdoctoral Science Foundation of China under grant 2013M541283. L.Z. acknowledges funding support from the Recruitment Program of Global Youth Experts in China. Part of calculations was performed in the high performance computing center of Jilin Univ. R.J.N. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the UK [EP/J017639/1]. R.J.N. and C.J.P. acknowledge use of the Archer facility of the U.K.’s national high-performance computing service (for which access was obtained via the UKCP consortium [EP/K013564/1]).This is the final version of the article. It first appeared from ACS via https://doi.org/10.1021/acs.chemmater.5b0463