Results 11 to 20 of about 181,676 (138)
, 2023 高超声速边界层是一个基础的科学问题。为了研究高超声速平板边界层的流场特性，结合数值模拟、理论求解和试验验证三种手段进行综合分析。数值模拟对二维Navier-Stokes (N-S)方程采用五阶精度的WENO格式离散对流项、六阶中心格式离散黏性项，时间推进项采用三阶Runge-Kutta法。理论分析利用四阶Runge-Kutta结合打靶法求解得到可压缩平板边界层层流自相似解。试验验证利用中科院力学所JF-12复现风洞测试得到大尺度平板的壁面热流，大尺度的平板模型布置传感器达到了较高的空间分辨率 ...
姜宗林, 刘美宽, 韩桂来
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, 2022 在高马赫数飞行条件下，斜爆轰发动机热力学循环效率高，燃烧室长度短，是近些年国内外研究热点。目前斜爆轰发动机试验研究使用的都是氢气或者乙烯燃料，还没有使用航空煤油的试验结果。为了研究RP3航空煤油应用于斜爆轰发动机的可行性，在JF–12激波风洞上开展了冷态RP3航空煤油斜爆轰发动机自由射流试验研究，JF–12激波风洞有效试验时间50 ms。针对航空煤油点火延迟时间长的难点，提出了鼓包强制起爆新技术。模拟的飞行马赫数为9，试验气流总温为3 800 K，全局当量比为0.9。试验中获得了稳定的斜爆轰波 ...
苑朝凯 +5 more
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, 1985 本文通过对LY12-CZ铝合金板材光滑试件和中心孔试件的常幅加载和变幅加载疲劳试验,对Miner累积损伤理论进行了试验验证,并对累积周比的分散性作了统计分析,发现累积周比的分散性服从Weibull分布 ...
伍义生
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Gaoya dianqi, 2020 为了验证晶闸管可否承受设计要求的最高结温及高低温循环应力,在出厂试验阶段需要开展换流阀温升试验。首先介绍了温升试验参数的计算方法,其次设计了采用直流电流加热原理的温升试验回路,最后结合某换流阀实例计算了温升试验参数,在试验室中开展了温升试验。试验结果显示温升试验参数的试验值和计算值基本一致,试验前后晶闸管性能未有下降。试验结果表明,结合给出的温升试验参数计算方法和温升试验回路可以完成温升试验,验证晶闸管的温升性能。
张翔 +5 more
doaj
10kV线路用多腔室间隙防雷装置工频续流遮断能力检验方案验证
Dianci bileiqi, 2020 根据标准T/CSEE 0082—2018《中压配电线路用多腔室间隙防雷装置通用技术条件》中10 kV系统用多腔室间隙防雷装置的工频续流遮断能力试验方案,笔者采用LC工频振荡电源和冲击电压源搭建了一种工频电流遮断试验回路,并对该回路进行了性能测试,测试结果表明该试验回路能同时满足标准所述试验方案对试验回路的输出电压、输出电流、相位同步控制的技术要求。进一步为验证标准所述试验方案应用于实际产品检测的可行性,利用该试验回路对两种共20只试品进行工频续流遮断能力试验,检测结果表明,该试验回路满足标准T/CSEE
姚尧 +6 more
doaj
International Journal of Applied Linguistics, EarlyView.ABSTRACT Although the use of AI technologies (e.g., chatbots and automated writing evaluations (AWE)) has gained considerable attention in language learning fields in recent years, how AI technologies have been designed and implemented in language learning education, as well as their effectiveness, is understudied.
Shen Qiao +2 more
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The Development and Validation of the Chinese Vocabulary Levels Test
International Journal of Applied Linguistics, EarlyView.ABSTRACT In response to the increasing need for effective Chinese vocabulary assessments, this study developed the Chinese Vocabulary Levels Test (CVLT), a test designed for intermediate‐level Chinese as a second or foreign language (CSL/FL) learners, based on the vocabulary lists (levels 4–6) from the Chinese Proficiency Grading Standards for ...
Shiwei Qi, Ailan Fu
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Finetuning Pre‐Trained Language Models for Automatic Assessment of English‐Chinese Interpreting
International Journal of Applied Linguistics, EarlyView.ABSTRACT Recent years have seen growing interest in leveraging pre‐trained language models (PLMs) for automatic assessment of spoken‐language performance. Contributing to this emerging line of work, the present study offers the first attempt to finetune two PLMs, GTE‐multilingual and mmBERT, for assessing English‐Chinese interpreting, using over 1700 ...
Zhaokun Jiang, Chao Han
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, 2012 本发明涉及一种微扭矩力学试验机及其测试方法。该试验机包括：控制装置和试验机主机，所述控制装置用于设置试验方法，向试验机主机发出命令和分析处理从试验机主机得到的实验数据；所述试验机主机用于对试样进行加载。测试方法包括：通过定制的试验软件控制信号发生模块产生一电压信号，经调理放大后驱动试验机主机工作；信号采集模块采集角度信号和线圈的驱动信号；将采集到的角度信号换算为旋转角，将采集到的线圈驱动信号换算为扭矩；按照力学模型进行数据处理，得出被测试样的切应力一切应变曲线，进而可进一步计算出剪切模量和剪切强度 ...
郇勇, 张泰华
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Multifunctional thermal protective ceramic thermal/environmental barrier coatings (T/EBCs) are of great significance for applications of various high‐temperature components, and we propose an effective strategy for designing high‐entropy ceramics (HECs) as T/EBCs for SiC ceramic matrix composites (CMCs), where low thermal expansion ...
Qinshuo Wang +7 more
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