16 research outputs found

    New understandings of the June 24th 2017 Xinmo Landslide, Maoxian, Sichuan, China

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    On June 24, 2017 (21:39 UTC, June 23rd), a catastrophic landslide occurred at Xinmo village of Mao County, Sichuan Province, China. Soon after the event, some research teams carried out field investigations in order to both support the emergency operations and to understand the failure mechanism and possible evolutionary scenarios. Based on further in-depth interpretation of high-resolution remote-sensing images and detailed field surveys, it is newly found that there are at least six old rockfall deposits in the source area that prove the historic activity of the landslide scarp. Seismic data of the event and morphological evidences along the slope indicate that the landslide was preceded by a significant rockfall. Mechanical calculations show that the surface force due to pore water was far less than the impact force due to the rockfall. It means that the subsequent major rock avalanche was more likely due to the impact of the rockfall on the rock slope below, which broke the rock bridges and caused drop of shear resistance along the fractures. According to these new understandings, a different triggering mechanism for the landslide is proposed

    A Randomized Controlled Trial of an Integrated Brain, Body, and Social Intervention for Children With ADHD

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    Objective: This study evaluated the efficacy of an Integrated Brain, Body, and Social (IBBS) intervention for children with ADHD. Treatment consisted of computerized cognitive remediation training, physical exercises, and a behavior management strategy. Method: Ninety-two children aged 5 to 9 years with ADHD were randomly assigned to 15 weeks of IBBS or to treatment-as-usual. Primary outcome measures included blinded clinician ratings of ADHD symptoms and global clinical functioning. Secondary outcome measures consisted of parent and teacher ratings of ADHD and neurocognitive tests. Results: No significant treatment effects were found on any of our primary outcome measures. In terms of secondary outcome measures, the IBBS group showed significant improvement on a verbal working memory task; however, this result did not survive correction for multiple group comparisons. Conclusion: These results suggest that expanding cognitive training to multiple domains by means of two training modalities does not lead to generalized improvement of ADHD symptomatology

    The Effect of Fixing Method on the Result of Ultrasonic Infrared Thermography Testing

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    Considering the influence of the fixing method of the component in the system on its results in ultrasonic infrared thermography testing, the detection experiments of the cracked plat structure with fixing at one end and fixing at two ends are carried out through different fixing methods of the equivalent structure. The results show that for the same structure to be detected, the more the bounds are fixed, the more the degrees of freedom are restricted, the less ultrasonic energy is dissipated during the inspection process, and the better the inspection effect. The work has positive significance for the selection of detection parameters in ultrasonic infrared thermography testing, helpful to provide some references for it

    Evolution of the Three-Dimensional Structure and Growth Model of Plasma Electrolytic Oxidation Coatings on 1060 Aluminum Alloy

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    A deeper understanding of plasma electrolytic oxidation (PEO) can in turn shed light on the evolution of coating structures during such oxidation processes. Here, a three-dimensional (3D) structure of PEO coating was investigated based on the morphologies at different locations in a PEO coating and on the elemental distribution along certain sections. The coating surface was dominated by a crater- or pancake-like structure of alumina surrounded by Si-rich nodules. A barrier layer with a thickness of ~1 μm consisting of clustered cells was present at the aluminum/coating interface. As the coating thickened, the PEO coating gradually evolved into a distinct three-layer structure, which included a barrier layer, an internal structure with numerous closed holes, and an outer layer with a rough surface. During the PEO process, molten zones formed along with the plasma discharges. The volume and lifetime of the molten zones changed with oxidation time. The diversities of cooling rates around the molten zones resulted in structural differences along a certain section of the coating. A growth and discharge model of PEO coatings was established based on the 3D structure of the particular coating studied herein

    Research on Power Allocation in Multiple-Beam Space Division Access Based on NOMA for Underwater Optical Communication

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    To meet the transmission requirements of different users in a multiple-beam access system for underwater optical communication (UWOC), this paper proposes a novel multiple-beam space division multiple access (MB-SDMA) system by utilizing a directional radiation communication beam of the hemispherical LED arrays. The system’s access users in the different beams are divided into two categories: the users with a single beam and the users with multiple beams. We also propose a power allocation algorithm that guarantees the quality of service (QoS) for single beam and multiple beam access, especially the QoS for edge users, and fairness for all users. An optimization model of power distribution under the constraints of specific light-emitting diode (LED) emission power is established for two scenarios, which ensure the user QoS for edge users and the max–min fairness for fair users. Using the Karush–Kuhn–Tucker (KKT) condition and the bisection method, we obtain the optimal power allocation expression for the two types of users in the optimization model. Through simulation, we verify that the proposed user classification and power allocation method can ensure the fairness of fair users on the premise of ensuring the QoS of edge users. At the same time, we know that the number of users will affect the improvement of the minimum rate, and the throughput of the non-orthogonal multiple access (NOMA) system is greatly improved compared with the traditional orthogonal multiple access (OMA) systems

    Embedded into Graphene Ge Nanoparticles Highly Dispersed on Vertically Aligned Graphene with Excellent Electrochemical Performance for Lithium Storage

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    Decreasing particle size has always been reported to be an efficient way to improve cyclability of Li-alloying based LIBs. However, nanoparticles (NPs) tend to agglomerate and evolve into lumps, which in turn limits the cycling performance. In this report, we prepared a unique nanostructure, graphene-coated Ge NPs are highly dispersed on vertically aligned graphene (Ge@graphene/VAGN), to avoid particle agglomeration and pulverization. Remarkable structure stability of the sample leads to excellent cycling stability. Upon cycling, the anode exhibits a high capacity of 1014 mAh g<sup>–1</sup>, with nearly no capacity loss in 90 cycles. Rate performance shows that even at the high current density of 13 A g<sup>–1</sup>, the anode could still deliver a higher capacity than that of graphite

    Research on Power Allocation in Multiple-Beam Space Division Access Based on NOMA for Underwater Optical Communication

    No full text
    To meet the transmission requirements of different users in a multiple-beam access system for underwater optical communication (UWOC), this paper proposes a novel multiple-beam space division multiple access (MB-SDMA) system by utilizing a directional radiation communication beam of the hemispherical LED arrays. The system&rsquo;s access users in the different beams are divided into two categories: the users with a single beam and the users with multiple beams. We also propose a power allocation algorithm that guarantees the quality of service (QoS) for single beam and multiple beam access, especially the QoS for edge users, and fairness for all users. An optimization model of power distribution under the constraints of specific light-emitting diode (LED) emission power is established for two scenarios, which ensure the user QoS for edge users and the max&ndash;min fairness for fair users. Using the Karush&ndash;Kuhn&ndash;Tucker (KKT) condition and the bisection method, we obtain the optimal power allocation expression for the two types of users in the optimization model. Through simulation, we verify that the proposed user classification and power allocation method can ensure the fairness of fair users on the premise of ensuring the QoS of edge users. At the same time, we know that the number of users will affect the improvement of the minimum rate, and the throughput of the non-orthogonal multiple access (NOMA) system is greatly improved compared with the traditional orthogonal multiple access (OMA) systems

    All-Solid-State Symmetric Supercapacitor Based on Co<sub>3</sub>O<sub>4</sub> Nanoparticles on Vertically Aligned Graphene

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    We have synthesized the hybrid supercapacitor electrode of Co<sub>3</sub>O<sub>4</sub> nanoparticles on vertically aligned graphene nanosheets (VAGNs) supported by carbon fabric. The VAGN served as an excellent backbone together with the carbon fabric, enhancing composites to a high specific capacitance of 3480 F/g, approaching the theoretical value (3560 F/g). A highly flexible all-solid-state symmetric supercapacitor device was fabricated by two pieces of our Co<sub>3</sub>O<sub>4</sub>/VAGN/carbon fabric hybrid electrode. The device is suitable for different bending angles and delivers a high capacitance (580 F/g), good cycling ability (86.2% capacitance retention after 20 000 cycles), high energy density (80 Wh/kg), and high power density (20 kW/kg at 27 Wh/kg). These excellent electrochemical performances, as a result of the particular structure of VAGN and the flexibility of the carbon fabric, suggest that these composites have an enormous potential in energy application

    A Randomized Controlled Trial of an Integrated Brain, Body, and Social Intervention for Children With ADHD

    No full text
    Objective: This study evaluated the efficacy of an Integrated Brain, Body, and Social (IBBS) intervention for children with ADHD. Treatment consisted of computerized cognitive remediation training, physical exercises, and a behavior management strategy. Method: Ninety-two children aged 5 to 9 years with ADHD were randomly assigned to 15 weeks of IBBS or to treatment-as-usual. Primary outcome measures included blinded clinician ratings of ADHD symptoms and global clinical functioning. Secondary outcome measures consisted of parent and teacher ratings of ADHD and neurocognitive tests. Results: No significant treatment effects were found on any of our primary outcome measures. In terms of secondary outcome measures, the IBBS group showed significant improvement on a verbal working memory task; however, this result did not survive correction for multiple group comparisons. Conclusion: These results suggest that expanding cognitive training to multiple domains by means of two training modalities does not lead to generalized improvement of ADHD symptomatology.</p
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