Public Security Risk m Large Scale Activities and the Standardization Prospects

This paper generalizes the definition and its scope of large scale activity based on its current practice and supervision system in China, makes risk analysis during activities, and puts forward proposals on carrying out relevant standardization works after discussions about the actuality and prospect of social security on large scale activities in China.

Research on the Characteristics of Large Earthquake Activity on the Active Tectonic Boundaries on the Chinese Mainland

Based on the research and the division of the active tectonic blocks and their boundaries on the Chinese mainland, the feature of the large earthquake activities on the 24 boundaries between the 6 active tectonic block regions (grade Ⅰ) and the 22 active tectonic blocks (grade Ⅱ) are studied. The seismicity levels on the active tectonic block boundaries are discussed considering the large earthquake frequency and the released strain energy in unit distance and time. The theoretic maximal magnitude and the recurrence period of each boundary are then calculated from the G-R relation. By comparing this with the actual earthquake records, it is found that the intensities of the earthquake deduced from the seismic activity parameter (a/b) on the main active boundaries on the Chinese mainland are consistent with that of the natural earthquakes. Meanwhile, an inverse relation is found between the recurrence periods of large earthquakes and the tectonic motion rate on the boundaries. These results show that the a, b values of each boundary obtained in this paper are valuable. In addition, the present seismic activities and hazards of these boundaries are also probed into with the historical data and their elapsed time on each boundary based on the hypothesis that the large earthquakes satisfy Poisson distribution.

Analysis of Evacuation Efficiency with Congestion Points in Large Sport Facilities

Large leisure activities usually use large sport facilities. There is often no serious problem with people gathering, but both incomplete facilities and negligence of people security manage may court injury or death. The purpose of this study is to analyze crowded nodes and to improve evacuation path use Simulex models. The fastest and safest way to achieve safe egress was then well planned. For turn locations, it was found that fixing the plane angle did not significantly raise the overall exiting efficiency. However, replacing the right angle or other angles with arc angle makes overall exiting moving line more fluent. For multito single-directional converging T-junction intersections, modification of turn angle increased the movement fluency, with the higher the modified angle, the higher in fluency. However, changing to round angle did not have as significant effect as expected while gate opening width must be increased to 1.0 m before more significant effects were produced. The results showed that modifying turn angles to 60° produces better improvements.

The Active Yakutat （Kula？） Plate and Its Southcentral Alaska Megathrust and Intraplate Earthquakes

Alaska geology and plate tectonics have not been well understood due to an active Yakutat plate, believed to be part of the remains of an ancient Kula plate, not being acknowledged to exist in Alaska. It is positioned throughout most of southcentral Alaska beneath the North American plate and above the NNW subducting Pacific plate. The Kula？ plate and its eastern spreading ridge were partially ＂captured＂ by the North American plate in the Paleocene. Between 63 Ma and 32 Ma, large volumes of volcanics erupted from its subducted N-S striking spreading ridge through a slab window. The eruptions stopped at 32 Ma, likely due to the Pacific plate fiat-slab subducting from the south beneath this spreading ridge. At 28 Ma, magmatism started again to the east; indicating a major shift to the east of this ＂refusing to die＂ spreading ridge. The captured Yakutat plate has also been subducting since 63 Ma to the WSW. It started to change to WSW fiat-slab subduction at 32 Ma, which stopped all subduction magmatism in W and SW Alaska by 22 Ma. The Yakutat plate subduction has again increased with the impact/joining of the coastal Yakutat terrane from the ESE about 5 Ma, resulting in the Cook Inlet Quaternary volcanism of southcentral Alaska. During the 1964 Alaska earthquake, sudden movements along the southcentral Alaska thrust faults between the Yakutat plate and the Pacific plate occurred. Specifically, the movements consisted of the Pacific plate moving NNW under the buried Yakutat plate and of the coastal Yakutat terrane, which is considered part of the Yakutat plate, thrusting WSW onto the Pacific plate. These were the two main sources of energy release for the E part of this earthquake. Only limited movement between the Yakutat plate and the North American plate occurred during this 1964 earthquake event. Buried paleopeat age dates indicate the thrust boundary between the Yakutat plate and North American plate will move in about 230 years, resulting in a more ＂continental＂ type megathrust earthquake for southcentral Alaska. There are, therefore, at least two different types ofmegathrust earthquakes occurring in southcentral Alaska： the more oceanic 1964 type and the more continental type. In addition, large ＂active＂ WSW oriented strike-slip faults are recognized in the Yakutat plate, called slice faults, which represent another earthquake hazard for the region. These slice faults also indicate important oil/gas and mineral resource locations.

Multiscale manipulating induced flexible heterogeneous V-NiFe_(2)O_(4)@Ni_(2)P electrocatalyst for efficient and durable oxygen evolution reaction

Water electrolysis is severely impeded by the kinetically sluggish oxygen evolution reaction(OER)due to its inherent multistep four-electron transfer mechanism.However,designing advanced OER electrocatalysts with abundant active sites,robust stability,and low cost remains a huge challenge.Herein,a facile and versatile multiscale manipulating strategy was proposed to construct a novel V-NiFe_(2)O_(4)@Ni_(2)P heterostructure self-supported on Ni foam(V-NiFe_(2)O_(4)@Ni_(2)P/NF).In such unique architecture,the intrinsic OER catalytic activity was greatly boosted by the in-situ generated heterogeneous Ni_(2)P phase induced by precisely selective phosphorylation of the NiFe-precursor,while the synchronous metal V doping stimulated the activity via modulating the electronic configuration,thus synergistically promoting its OER kinetics.In addition,the binder-free catalyst built from three-dimensional(3D)nanosheet arrays(NSs)can offer a large active surface for efficient charge/mass transfer and a robust scaffold for the integrated structure.The as-prepared flexible electrode exhibited superior OER activity with an ultra-low overpotential of 230 mV at 50 mA·cm^(−2)and outstanding long-term stability for 40 h.This discovery is expected to provide an opportunity to explore efficient and stable commercial materials for scalable,efficient,and robust electrochemical hydrogen(H_(2))production.

THEORY OF DIELECTRIC ELASTOMERS

In response to a stimulus, a soft material deforms, and the deformation provides a function. We call such a material a soft active material （SAM）. This review focuses on one class of soft active materials： dielectric elastomers. When a membrane of a dielectric elastomer is subject to a voltage through its thickness, the membrane reduces thickness and expands area, possibly straining over 100%. The dielectric elastomers are being developed as transducers for broad applications, including soft robots, adaptive optics, Braille displays, and electric generators. This paper reviews the theory of dielectric elastomers, developed within continuum mechanics and thermodynamics, and motivated by molecular pictures and empirical observations. The theory couples large deformation and electric potential, and describes nonlinear and nonequilibrium behavior, such as electromechanical instability and viscoelasticity. The theory enables the finite element method to simulate transducers of realistic configurations, predicts the efficiency of electromechanical energy conversion, and suggests alternative routes to achieve giant voltage-induced deformation. It is hoped that the theory will aid in the creation of materials and devices.