Results 1 to 10 of about 7,996 (108)
Kongjian kexue xuebao, 2023 以实际广播星历、精密星历和北斗星基增强系统(BDSBAS)增强报文为实验数据，通过计算BDSBAS轨道误差、卫星钟差、空间信号测距误差和BDSBAS格网电离层有效点、播发时间和电离层延迟误差6个指标，评估分析了BDSBAS空间信号的性能。结果显示：BDSBAS增强后的GPS卫星轨道误差在切向、法向、径向分别降低了34.57%，40.57%，30.90%；卫星钟差均方根降低了24.31%，卫星钟差标准差降低了16.8%；空间信号测距误差相比增强前降低了32.75 ...
刘 瑞华, 耿 海潮, 刘 亮
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Kongjian kexue xuebao, 2023 小天体检测是小天体防御和预警的前提。针对小天体目标信噪比低、检测难的问题，提出了基于统计特征空间提取和支持向量机（SVM）的极暗弱小天体检测方法。区别于传统方法基于时间或空间上目标的能量和背景噪声能量的瞬时能量差别或是瞬时能量差别的累积，对目标进行检测。该方法不依赖目标能量大小，提取运动目标穿过背景时对稳定性产生的扰动来反演运动目标。将输入的图像序列转化为单像元时序信号，划分时序窗口提取统计特征，关联形成统计特征空间，利用更高维度的变化特性检测目标变化 ...
王 存远, 郑 伟, 李 明涛
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Dianxin kexue面向低空经济快速发展对通信与感知能力的双重需求，系统分析了低空场景下的业务特征与网络挑战，提出基于5G-A的低空覆盖组网策略。首先，从低空通信与感知两大维度梳理典型业务需求，明确高可靠、大带宽、低时延与通感融合等核心指标；其次，围绕通信与感知组网架构，探讨航区与航线覆盖的关键问题，重点分析传播模型、塔顶弱覆盖等制约因素，并提出航区蜂窝塔顶补盲、航线蝶形双侧避盲组网结构；最后，面向全面保障低空无人机体验，提出通感增强、多元融合感知等新技术引入方向。研究成果可为低空网络覆盖规模化建设提供技术支撑与参考。
曹阳阳 +5 more
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Conservation Biology, EarlyView.Abstract Robust estimates of the magnitude of protected species bycatch are essential for effective fisheries management and marine conservation. Existing bycatch estimation methods typically struggle to accurately and precisely estimate the bycatch of rare species as a result of the statistical assumptions necessary to overcome infrequent encounters ...
Christopher Long +3 more
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大数据, 2023 随着数字经济的飞速发展，以及“全国一体化数据中心”和“东数西算”等基础设施的不断完善，数据要素流通的大趋势使数据服务逐步由面向单一空间域的数据管理转变为面向跨空间域的数据管理。跨域数据管理需要通过分布式共识算法使数据一致。然而，已有的分布式共识算法仅考虑单数据中心的情况，没有考虑跨数据中心之间的网络通信的不确定性，从而在跨空间域场景下面临日志同步时延大、系统吞吐量低下等问题。系统地梳理了跨空间域下的分布式共识算法的现状以及面临的新挑战，并针对解决这些挑战的技术路线进行了展望。
李伟明, 李彤, 张大方, 戴隆超, 柴云鹏
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International Journal of Applied Linguistics, EarlyView.ABSTRACT As digitally mediated communication increasingly shapes language learning beyond formal classrooms, social media platforms offer new possibilities for authentic, intercultural interaction. This qualitative study investigates how TikTok Live‐mediated interaction supports English as a lingua franca (ELF) use, meaning‐making, and intercultural ...
Wen‐Chi Vivian Wu +2 more
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Dianxin kexue4.9 GHz作为中国移动特色频率，如何合理规划、有效满足通信和感知等业务需求至关重要。聚焦中国移动4.9 GHz频率使用策略，首先，结合低空通信、感知、地面通信业务现状，分析典型业务需求情况；其次，详细研究通信与通信、感知与感知、通信与感知间干扰，给出低空通信、感知、地面通信频段使用策略建议；最后制定4.9 GHz网络部署建议，为后续移动通信业务有序承载、科学管理运营提供支撑。
张琪璇 +6 more
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Lung cancer remains a major cause of cancer‐related mortality worldwide, and non‐small cell lung cancer (NSCLC) accounts for the largest proportion of diagnosed lung cancer cases. Exosomal programmed death‐ligand 1 (PD‐L1) has attracted increasing attention as a potential liquid‐biopsy biomarker associated with tumor immune regulation; however,
Chen Su +6 more
wiley +1 more source
Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT The immunosuppressive milieu of hepatocellular carcinoma (HCC) remains a major obstacle to durable antitumor responses. Mechanical‐energy‐driven piezocatalysis provides a noninvasive means of inducing oxidative damage and immunogenic tumor destruction; however, inefficient utilization of piezoinduced charges and insufficient localization of ...
Mingjian Zhang +7 more
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Conservation Biology, Volume 40, Issue 5, October 2026.Abstract Ecological niche models (ENMs) are used to assess the abiotic preferences of species by linking their occurrences to the environmental conditions in which they live. We developed a fossil‐informed ENM framework that integrates mid‐Holocene and modern occurrences to test niche stability and reconstruct abiotic niche characteristics for four ...
Claire. M. Williams +3 more
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