324 research outputs found

    ftp ejde.math.txstate.edu (login: ftp) PYRAMIDAL CENTRAL CONFIGURATIONS AND PERVERSE SOLUTIONS

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    Abstract. For n-body problems, a central configuration (CC) plays an important role. In this paper, we establish the relation between the spatial pyramidal central configuration (PCC) and the planar central configuration. We prove that the base of PCC is also a CC and we also prove that for some given conditions a planar CC can be extended to a PCC. In particular, if the pyramidal central configuration has a regular polygon base, then the masses of base are equal and the distance between the top vertex and the base is fixed and the mass of the top vertex is selective. Furthermore, the pyramidal central configuration gives rise to an example of a perverse solution in R3

    Expressions of Cyr61 and WISP-3 in Non-small Cell Lung Cancer and Its Clinical Significance

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    Background and objective Cysteine-rich protein 61 (Cyr61) plays a role as a tumor suppressor in non-small cell lung cancer (NSCLC). Cyr61 and WISP-3 have a very significant sequence homology, belonging to the same CCN gene family. The aim of this study is to investigate the expressions of Cyr61 and WISP-3 in NSCLC, and explore the relationship between their expressions and tumor's clinicopathological characteristics. Methods The expressions of Cyr61 and WISP-3 were detected in 54 cases with primary NSCLC and their corresponding normal lung tissues in control group by immunohistochemical staining (SP), and the clinical data were analyzed. Results Down-regulation of Cyr61 and up-regulation of WISP-3 were both found in lung cancer tissue compared with the corresponding normal lung tissue (both P < 0.001); The expression of Cyr61 was negatively correlated with the expression of WISP-3 (r=-0.395, P=0.003); Cyr61 expression levels was closely correlated with tumor grade, tumor type, clinical stage, family history, smoking and metastasis (P < 0.05). Also, WISP-3 was closely correlated with tumor grade, clinical stage and age (P < 0.05). Conclusion The expressions of Cyr61 and/or WISP-3 may be important biological markers in reflecting the progression, biological behaviors, metastatic potential and prognosis of NSCLC

    Analysis of the Hydroelastic Performance of Very Large Floating Structures Based on Multimodules Beam Theory

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    The hydroelastic behavior of very large floating structures (VLFSs) is investigated based on the proposed multimodules beam theory (MBT). To carry out the analysis, the VLFS is first divided into multiple submodules that are connected through their gravity center by a spatial beam with specific stiffness. The external force exerted on the submodules includes the wave hydrodynamic force as well as the beam bending force due to the relative displacements of different submodules. The wave hydrodynamic force is computed based on three-dimensional potential theory. The beam bending force is expressed in the form of a stiffness matrix. The motion response defined at the gravity center of the submodules is solved by the multibody hydrodynamic control equations; then both the displacement and the structure bending moment of the VLFS are determined from the stiffness matrix equations. To account for the moving point mass effects, the proposed method is extended to the time domain based on impulse response function (IRF) theory. The method is verified by comparison with existing results. Detailed results through the displacement and bending moment of the VLFS are provided to show the influence of the number of the submodules and the influence of the moving point mass

    The Polarizing Trend of Regional CO2 Emissions in China and Its Implications

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    CO2 emissions are unevenly distributed both globally and regionally within nation-states. Given China's entrance into the new stage of economic development, an updated study on the largest CO2 emitter's domestic emission distribution is needed for effective and coordinated global CO2 mitigation planning. We discovered that domestic CO2 emissions in China are increasingly polarized for the 2007-2017 period. Specifically, the domestically exported CO2 emissions from the less developed and more polluting northwest region to the rest of China has drastically increased from 165 Mt in 2007 to 230 Mt in 2017. We attribute the polarizing trend to the simultaneous industrial upgrading of all regions and the persistent disparity in the development and emission decoupling of China's regions. We also noted that CO2 emissions exported from China to the rest of the world has decreased by 41% from 2007 to 2017, with other developing countries filling up the vacancy. As this trend is set to intensify, we intend to send an alarm message to policy makers to devise and initiate actions and avoid the continuation of pollution migration

    Large piezoelectric properties in KNN-based lead-free single crystals grown by a seed-free solid-state crystal growth method

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    We report lead-free single crystals with a nominal formula of (K₀.₄₅Na₀.₅₅)₀.96Li₀.₀₄NbO₃grown using a simple low-cost seed-free solid-state crystal growth method (SFSSCG). The crystals thus prepared can reach maximum dimensions of 6 mm × 5 mm × 2 mm and exhibit a large piezoelectric coefficient d₃₃ of 689 pC/N. Moreover, the effective piezoelectric coefficient d₃₃*, obtained under a unipolar electric field of 30 kV/cm, can reach 967 pm/V. The large piezoelectric response plus the high Curie temperature (TC) of 432 °C indicate that SFSSCG is an effective approach to synthesize high-performance lead-free piezoelectricsingle crystals.This work was supported by the National Natural Science Foundation of China (NSFC, Nos. 51332009 and 51172257), National Basic Research Program of China 973- Projects (2012CB619406), the CAS/SAFEA International Partnership Program for Creative Research Teams, and Science and Technology Commission of Shanghai Municipality (15ZR1445400). Y.L. appreciates the financial support from the Australian Research Council in the form of Future Fellowship

    The comprehensive environmental efficiency of socioeconomic sectors in China: An analysis based on a non-separable bad output SBM

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    The increasingly high frequency of heavy air pollution in most regions of China signals the urgent need for the transition to an environmentally friendly production performance by socioeconomic sectors for the sake of people's health and sustainable development. Focusing on CO2 and major air pollutants, this paper presents a comprehensive environmental efficiency index based on evaluating the environmental efficiency of major socioeconomic sectors, including agriculture, power, industry, residential and transportation, at the province level in China in 2010 based on a slack-based measure DEA model with non-separable bad output and weights determined by the coefficient of variation method. In terms of the environment, 5, 16, 6, 7 and 4 provinces operated along the production frontier for the agricultural, power, industrial, residential and transportation sectors, respectively, in China in 2010, whereas Shanxi, Heilongjiang, Ningxia, Hubei and Yunnan showed lowest efficiency correspondingly. The comprehensive environmental efficiency index varied from 0.3863 to 0.9261 for 30 provinces in China, with a nationwide average of 0.6383 in 2010; Shanghai ranked at the top, and Shanxi was last. Regional disparities in environmental efficiency were identified. A more detailed inefficiency decomposition and benchmarking analysis provided insight for understanding the source of comprehensive environmental inefficiency and, more specifically, the reduction potential for CO2 and air pollutants. Some specific research and policy implications were uncovered from this work

    Swarm splitting and multiple targets seeking in multi-agent dynamic systems

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    This paper presents an approach to swarm split control of a system of multi-agents with limited sensing capabilities. The control scheme utilizes the competition between the inter-agent repulsive and attractive interactions and can split one cohesive swarm into several clustered subswarms along the direction perpendicular to the common heading direction of agents. The cohesion and collision avoidance of agents are ensured by long-range attractive and short-range repulsive interactions between agents. The split of swarm is achieved via a Gaussian-like repulsive interaction between agents, whose magnitude affects the number of subswarm clusters and can be designed to control the swarm splitting/rejoining maneuver, and whose maximum location mainly affects the relative distance between clustered subswarms. The split control law is also applied to double targets seeking task in a swarm of 100 agents, and simulations are worked out. These results are of interest in understanding and utilizing the splitting dynamics in swarms of agents with local coupling interactions.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000295049105038&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Automation & Control SystemsEngineering, Electrical & ElectronicEICPCI-S(ISTP)
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