Co-seismic deformation for the 2015 M_(W)7.8 Gorkha earthquake(Nepal)using near-field GPS data

Seasonal variations and common mode errors affect the precision of the Global Positioning System(GPS)time series.In this paper,we explore to improve the precision of coordinate time series,thereby providing a better detection of weak or transient deformation signals,particularly co-seismic signals.Based on 97 GPS stations,including the campaign and continuous GPS stations in Nepal and southern Tibet,we first consider seasonal variations and common errors,then obtain co-seismic deformation of the 2015 Gorkha earthquake in Nepal and southern Tibet.Our co-seismic rupture model is characterized by a shallow ramp and a deeper detachment fault,in agreement with the relocated aftershock sequence.Our results indicate that the earthquake rupture is mainly distributed in the upper-crustal fault,and the maximum slip is up to 8.0 m at~15.0 km depth located in the approximate-80 km east of the epicenter.The average slip is more than 5 m,and the total modelled magnitude is M_(W)7.84,consistent with the observed seismic moment.Our rupture model for the 2015 Gorkha earthquake suggests that the rupture zone is not only in the upper crustal Main Himalayan Thrust(MHT),but also spreads to the northern segment of the MHT.

Hierarchically porous Cu current collector with lithiophilic CuxO interphase towards high-performance lithium metal batteries

Lithium metal is one of the most promising anode materials for next-generation electrochemical energy storage due to low electrochemical potential and high specific capacity.However,large volume change and uncontrollable formation of lithium dendrite during cycling severely hinder the practical application of rechargeable Li metal batteries.Herein,we report a hierarchically porous Cu covered with lithiophilic CuxO(HPCu-CuxO) via femtosecond laser strategy in about 2 min as current collector for highperformance Li metal batteries.With precisely tunable pore volume and depth as well as lithiophilic CuxO interphase,the HPCu-CuxO not only guides homogeneous Li nucleation,resulting in a smooth and dendrite-free lithium surface,but also provides space to alleviate the volume expansion of Li metal anode,achieving excellent structure stability.Consequently,highly stable Coulombic efficiency and ultralow overpotential of 15 mV even up to 1000 h were achieved at the current density of 1 mA cm^(-2).Moreover,the resultant Li@HPCu-CuxO//LiFePO_(4) full battery delivered outstanding cycle stability and rate capability.These results offer a pathway toward high-energy-density and safe rechargeable Li metal batteries.

The top cited articles on glioma stem cells in Web of Science

BACKGROUND： Glioma is the most common intracranial tumor and has a poor patient prognosis. The presence of brain tumor stem cells was gradually being understood and recognized, which might be beneficial for the treatment of glioma. OBJECTIVE： To use bibliometric indexes to track study focuses on glioma stem cell, and to investigate the relationships among geographic origin, impact factors, and highly cited articles indexed in Web of Science. METHODS： A list of citation classics for glioma stem cells was generated by searching the database of Web of Science-Expanded using the terms ＂glioma stem cell＂ or ＂glioma, stem cell＇＂ or ＂brain tumor stem cell＂. The top 63 cited research articles which were cited more than 100 times were retrieved by reading the abstract or full text if needed. Each eligible article was reviewed for basic information on subject categories, country of origin, journals, authors, and source of journals. Inclusive criteria： （1） articles in the field of glioma stem cells which was cited more than 100 times; （2） fundamental research on humans or animals, clinical trials and case reports; （3） research article; （4） year of publication： 1899-2012; and （5） citation database： Science Citation Index-Expanded. Exclusive criteria： （1） articles needing to be manually searched or accessed only by telephone; （2） unpublished articles; and （3） reviews, conference proceedings, as well as corrected papers. RESULTS： Of 2 040 articles published, the 63 top-cited articles were published between 1992 and 2010. The number of citations ranged from 100 to 1 754, with a mean of 280 citations per article. These citation classics came from nineteen countries, of which 46 articles came from the United States. Duke University and University of California, San Francisco led the list of classics with seven papers each. The 63 top-cited articles were published in 28 journals, predominantly Cancer Research and Cancer Cell, followed by Cell Stem Cell and Nature. CONCLUSION： Our bibliometric analysis provides a historical perspective on the progress of glioma stem cell research. Articles originating from outstanding institutions of the United States and published in high-impact journals are most likely to be cited.

Protective effects and time course of Huangqi on early-stage free radical injury following brain trauma in rats

BACKGROUND： Huangqi （Astragalus mongholicus）, a Chinese herb, has already been included in the ＂Chinese Pharmacopoeia＂ for the treatment of ischemic cerebrovascular disease. Secondary injury following brain injury is associated with free radical production, and Huangqi possesses the ability to ameliorate free radical-mediated injury. OBJECTIVE： This study was designed to observe the correlation between anti-free-radical properties of Huangqi and early histological changes of brain tissues following traumatic brain injury. DESIGN, TIME AND SETTING： This study, a randomized, controlled, animal experiment, was performed from May 2006 to June 2007 at the Experimental Center of Science and Technology, School of Basic Science, Liaoning Medical University, Jinzhou City, Liaoning Province, China. MATERIALS： Healthy, adult, Sprague Dawley rats of either gender were included. Huangqi injection was purchased from Heilongjiang Provincial Zhenbaodao Pharmaceutical Co., Ltd., China （National License Medical Number： Z23020781）. Na^＋-K^＋-adenosine triphosphatase （ATPase）, Ca^2＋-ATPase, and Mg^2＋-ATPase, as well as kits to measure superoxide dismutase （SOD） activity and malondialdehyde （MDA） content, were purchased from Nanjing Jiancheng Biological Reagent Company, China. METHODS： Seventy-two rats were randomly divided into three groups, with 24 rats in each group： （1） sham-operated group： rats were only exposed, but not injured; （2） model group： brain focal laceration rat models were established by free-falling. These groups were intraperitoneally injected with saline, once every 10 hours; （3） Huangqi group： rats were intraperitoneally injected with 4 mL/kg Huangqi （2 g/mL）, once every 10 hours, following brain focal laceration by free-falling. MAIN OUTCOME MEASURES： Ultrastructural changes in brain tissue were observed under an electron microscope 24 hours after injury. The water content of brain tissue was measured using the dry-wet weight method. In addition, the activity of ATPase and SOD, as well as MDA content, was analyzed using biochemical indicators at 4, 24, and 48 hours after injury. RESULTS： All 72 rats were included in the final analysis. At 4, 24, and 48 hours after injury, ATPase activity was significantly reduced in the model and Huangqi groups than in the sham-operated group （P 〈 0.05）, and this was reduction was time-dependent. At four hours after injury, no significant difference in ATPase activity was detected between the Huangqi group and the model group （P 〉 0.05）. At 24 and 48 hours after injury, ATPase activity in the Huangqi group gradually decreased, but remained significantly greater than that in the model group （P 〈 0.05）. At four hours after injury, when compared with the sham-operated group, the MDA content in the model group significantly increased and remained at a high level, while SOD activity significantly decreased （P 〈 0.05）. In the Huangqi group, MDA content and SOD activity did not change at four hours after injury. However, MDA content significantly decreased, and SOD activity significantly increased, at 24 and 48 hours after injury, compared with the model group （P 〈 0.05）. Moreover, at 24 and 48 hours after injury, the water content of brain tissue was significantly lower in the Huangqi group than in the model group （P 〈 0.05）. Ultrastructural examination of cerebral cortical neurons revealed severe damage in the model group, compared to the sham-operated group, while only mild injury was observed in the Huangqi group. CONCLUSION： The protective effects of Huangqi against traumatic brain injury correlates with decreasing MDA content and increasing SOD activity.

Dynamical analysis in a piecewise smooth predator-prey model with predator harvesting

The aim of this paper is to study the dynamical behaviors of a piecewise smooth predator-prey model with predator harvesting.We consider a harvesting strategy that allows constant catches if the population size is above a certain threshold value(to obtain predictable yield)and no catches if the population size is below the threshold(to protect the population).It is shown that boundary equilibrium bifurcation and sliding grazing bifurcation can happen as the threshold value varies.We provide analytical analysis to prove the existence of sliding limit cycles and sliding homoclinic cycles,the coexistence of them with standard limit cycles.Some numerical simulations are given to demonstrate ourresults.

Accurate prediction of oxygen vacancy concentration with disordered A-site cations in high-entropy perovskite oxides

Entropic stabilized ABO_(3) perovskite oxides promise many applications,including the two-step solar thermochemical hydrogen(STCH)production.Using binary and quaternary A-site mixed{A}FeO_(3) as a model system,we reveal that as more cation types,especially above four,are mixed on the A-site,the cell lattice becomes more cubic-like but the local Fe–O octahedrons are more distorted.By comparing four different Density Functional Theory-informed statistical models with experiments,we show that the oxygen vacancy formation energies(E^(f)_(V))distribution and the vacancy interactions must be considered to predict the oxygen non-stoichiometry(δ)accurately.For STCH applications,the E^(f)_(V) distribution,including both the average and the spread,can be optimized jointly to improveΔδ(difference ofδbetween the two-step conditions)in some hydrogen production levels.This model can be used to predict the range of water splitting that can be thermodynamically improved by mixing cations in{A}FeO_(3) perovskites.

A review on molten sulfate salts induced hot corrosion

Hot corrosion has been extensively observed in various high temperature applications,which might cause large economic losses.To deepen the insight and understanding of hot corrosion,herein,we provide a detailed discussion on hot corrosion induced by molten sulfate salt,in which Na_(2)SO_(4)is the main chemical reactant.The hot corrosion is triggered and sustained by the negative solubility gradient of protective oxide from the oxide/salt interface to salt/gas interface.In this work,we reviewed several key factors,including temperature,gas composition,molten salt composition,alloy element and external stress,influencing the hot corrosion of alloy beneath the molten salt.The application of anti-corrosion coating seems to be the most effective and commercial mothed to mitigate hot corrosion.Therefore,the progress of the development of effective coatings,e.g.,Ni-Cr coatings,aluminide coatings,silicide coatings and MCrAlY(X)coatings,has also been summarized.

任务强度差异支架对学生游戏化学习动机和沉浸感的影响

教育游戏的研究者发现,教育游戏中添加教学策略或学习支架能够帮助学生建立游戏和学科知识之间的联系,可以有效发挥游戏的教育价值,提高学生的学习效果和学习体验。本研究在梳理学习支架理论的基础上,针对"The Tiny Bang Story"游戏设计了两种不同强度的任务支架,以研究强度不同的任务支架对不同认知风格学生的学习动机和沉浸感的影响。研究发现:任务强度不同的学习支架对不同认知风格学生的学习动机和沉浸感的影响存在显著差异;场依存型学生的学习动机和沉浸感会随任务支架强度的增加而提升;场独立型学生的学习动机随任务支架强度的增加没有显著性变化,反而沉浸感会随任务支架强度的增加呈现先升后降的正三角趋势。

Degradation of solid oxide electrolysis cells: Phenomena,mechanisms, and emerging mitigation strategies——A review

Solid oxide electrolysis cell(SOEC) is a promising electrochemical device with high efficiency for energy storage and conversion.However,the degradation of SOEC is a significant barrier to commercial viability.In this review paper,the typical degradation phenomena of SOEC are summarized,with great attention into the anodes/oxygen electrodes,including the commonly used and newly developed anode materials.Meanwhile,mechanistic investigations on the electrode/electrolyte interfaces are provided to unveil how the intrinsic factor,oxygen partial pressure pO2,and the electrochemical operation conditions,affect the interracial stability of SOEC.At last,this paper also presents some emerging mitigation strategies to circumvent long-term degradation,which include novel infiltration method,development of new anode materials and engineering of the microstructure.

Homoclinic Flip Bifurcations Accompanied by Transcritical Bifurcation

The bifurcations of orbit flip homoclinic loop with nonhyperbolic equilibria are investigated. By constructing local coordinate systems near the unperturbed homoclinic orbit, Poincare maps for the new system are established. Then the existence of homoclinic orbit and the periodic orbit is studied for the system accompanied with transcritical bifurcation.

Nongeneric Bifurcations Near a Nontransversal Heterodimensional Cycle

In this paper bifurcations of heterodimensional cycles with highly degenerate conditions are studied in three dimensional vector fields,where a nontransversal intersection between the two-dimensional manifolds of the saddle equilibria occurs.By setting up local moving frame systems in some tubular neighborhood of unperturbed heterodimensional cycles,the authors construct a Poincar′e return map under the nongeneric conditions and further obtain the bifurcation equations.By means of the bifurcation equations,the authors show that different bifurcation surfaces exhibit variety and complexity of the bifurcation of degenerate heterodimensional cycles.Moreover,an example is given to show the existence of a nontransversal heterodimensional cycle with one orbit flip in three dimensional system.