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Dizhen xuebao, 2022 近断层地震动中存在的低频、大幅值速度脉冲使得临近断层结构具有更高的强度和延性需求。对近断层地震动脉冲特性的深入研究有利于加深对临近断层结构反应的认识，从而为临近断层结构抗震设计提供理论依据。受强震记录处理及速度脉冲识别和提取方法的限制，目前已有的研究工作主要集中于近断层地震动记录的单脉冲特性，多脉冲特性涉及较少。本文基于希尔伯特-黄变换及其相关理论，针对近断层地震动，提出了涵盖原始强震记录基线校正，至多速度脉冲定量判别及提取的整套脉冲特性研究方法，该方法对多脉冲记录尤为有效 ...
Dongsheng Wang +3 more
doaj +1 more source
Timing of hydrologic anomalies direct impacts on migration traits in a flood pulse fishery system
Journal of Applied Ecology, Volume 60, Issue 3, Page 494-506, March 2023., 2023 We designed a spectral analysis framework to quantify hydrological variation and linked it with fishery harvest records. Quantified effect sizes of hydrologic anomalous events demonstrated one designed hydrograph for fishery benefits: properly timed prolong drought followed by a strong flood pulse.
Qi Deng +4 more
wiley +1 more source
Rare Metals, Volume 42, Issue 1, Page 234-243, January 2023., 2023 Graphical abstract Abstract The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity‐dependent all‐optical switching (HD‐AOS), which hinders understanding the magnetization dynamics involved. Here, applying a dual‐pump laser excitation, first with a linearly polarized (LP) laser pulse followed by a
Guan‐Qi Li +9 more
wiley +1 more source
Near‐term ecological forecasting for dynamic aeroconservation of migratory birds
Conservation Biology, Volume 35, Issue 6, Page 1777-1786, December 2021., 2021 Abstract Near‐term ecological forecasting has the potential to mitigate negative impacts of human modifications on wildlife by directing efficient action through relevant and timely predictions. We used the U.S. avian migration system to highlight ecological forecasting applications for aeroconservation.
Kyle G. Horton +4 more
wiley +1 more source
Design of ternary pulsed JKL flip-flops(三值脉冲式JKL触发器设计)
Zhejiang Daxue xuebao. Lixue ban, 2010 锁存器和触发器是时钟系统的基本元件.由于具有硬边沿、低延时等特点,脉冲式触发器比主从触发器越来越受到关注.很多文献对二值脉冲式触发器进行了研究,但是目前对三值CMOS脉冲式触发器的研究并不多.本文从脉冲式触发器的特点出发,提出了单边沿、双边沿三值脉冲式JKL触发器的设计,进一步丰富和完善了多值脉冲式触发器的设计.HSPICE模拟结果表明,提出的三值脉冲式JKL触发器具有正确的逻辑功能和功耗低、延时小的特点.与从传统的主从型和维持阻塞型三值JKL触发器相比,所设计的三值脉冲式JKL触发器电路结构简单 ...
DAIYan-yun(戴燕云) +1 more
doaj +1 more source
, 2018 高推重比航空发动机普遍采用气膜冷却技术,叶片气膜冷却孔的加工精度直接影响发动机效能。气膜冷却孔具有孔径小、数量多、深径比高、空间角度复杂的特点,其加工难度大、成形精度要求高。针对当前国外对叶片气膜孔加工技术与装备的严格保密,以及国内气膜孔加工中存在的几何精度偏低、质量不稳定的现状,对气膜孔加工的现状及发展趋势进行归纳总结,为气膜孔加工技术与装备的发展提供参考。首先,概述了叶片气膜孔精确加工的必要性及其重要性,分别介绍了现有气膜孔的加工方法,分析了当前加工方法存在的问题与面临的挑战 ...
吴宗璞 +4 more
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Dizhen xuebao, 2018 为了研究速度脉冲型地震动的最强速度脉冲方向分量与垂直或平行断层方向分量之间的特性差异，本文采用多分量速度脉冲识别方法从NGA-West2强震动数据库的236组近断层地震动速度脉冲记录中提取出最强速度脉冲方向分量，对其脉冲参数随震级MW和断层距R变化的统计关系式进行了回归分析，并对比了最强速度脉冲方向分量与垂直或平行断层方向分量之间的特性差异。研究结果表明：当R＜30 km时，最强速度脉冲方向分量的脉冲幅值预测值较垂直或平行断层方向分量的预测值大，而当R＞30 km时，两种分量的脉冲幅值预测值相差不大 ...
Xiaofen Zhao, Zengping Wen, Bo Chen
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Joint channel and impulsive noise estimation method for MIMO-OFDM systems [PDF]
, 2021 Aiming at the impulsive noise occurring in MIMO-OFDM systems， a joint channel and impulsive noise estimation method based on the multiple measurement vector compressed sensing theory was proposed.The channel impulse response and the impulsive noise were ...
Qiang GUO, Xinrong LYU, Youming LI
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Research on deformation monitoring of surrounding rock based on weak fiber grating sensing technology [PDF]
, 2023 The prominent contradiction between high ground stress and low strength of surrounding rock in deep strata of coal mine leads to large deformation and instability disaster after roadway excavation.
Sheng WANG +3 more
core +1 more source
Study on the Mechanism of Discharge Channel and Thermal Effect in Micro-EDM [PDF]
, 2015 为了提高微细电火花加工的工件表面精度、控制加工过程的放电参数以及预测放电加工的结果，本文从微细电火花加工的基本机理出发，针对微细电火花加工过程中存在的研究难点进行了探索，并从介质击穿、通道扩张、能量分配以及热作用等几个方面开展了研究。主要研究工作如下： 首先，研究了微细电火花等离子体通道击穿机理及模型。从微细电火花加工的放电特性出发，提出了适用于微细电火花加工且结合了气泡机理与电子机理的击穿机理，并基于该击穿机理建立适用于微细电火花加工过程的击穿模型。 其次，研究了微细电火花等离子体通道扩张机理及模型 ...
朱凯
core