Results 11 to 20 of about 975,264 (156)
, 2008 尽管小波变换在数据压缩和去噪声等领域取得良好的效果，可分离的二维小波变换（不是直接构造出），采用先对行做一次一维小波变换，再对列做一次一维小波变换扩展而来。或者直接用二个可分离的一维函数基直接构造的二维变换，从数学角度都不是真正的二维函数。基函数的支撑区域由区间扩展为正方形，基函数形状的方向性较差,该问题制约着小波变换的进一步应用。同时，由于采用亚抽样技术，在目标提取时会造成信息模糊，对信息利用会产生较大的影响。众所周知，如果某个基函数能与被逼近的函数较好地匹配，则其相应的投影系数较大 ...
闫敬文, 屈小波
core
Ultrasonic Vibration Assisted Laser Processing: A Hybrid Paradigm for Extreme Surface Enhancement
Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Traditional laser processing techniques offer many advantages, but they often encounter limitations such as heat‐affected zones, recast layers, residual tensile stresses, and poor surface finish. The integration of ultrasonic vibration (UV) presents a promising hybrid approach to overcome these challenges by introducing beneficial effects like
Aziz Ul Hassan Mohsan +6 more
wiley +1 more source
Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Reflection loss (RL) ≤ −15 dB (corresponding to 96.875% electromagnetic energy absorption), a core metric for moderate‐ to high‐temperature (< 600°C) electromagnetic protection materials, is critical for ensuring the reliability of aerospace high‐temperature structural components.
Chunyan Ding +10 more
wiley +1 more source
Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT Magnetic particles coated with carbon shells have been considered as promising electromagnetic wave absorption materials with antibacterial features. However, how to precisely control the monodispersed magnetic nanoparticles on a carbon matrix to manipulate impedance matching and antibacterial performances is still a key challenge.
Xiaofei Li +10 more
wiley +1 more source
Rare Metals, Volume 45, Issue 9, September 2026.ABSTRACT In laser‐directed energy deposition (LDED) of TiC/Ti6Al4V composites, a low content of micron‐sized TiC provides a good strengthening effect on hardness and strength, but the improvement in plasticity remains a challenge. By introducing synchronous ultrasonic impact treatment (UIT) into the LDED process, an ultrasonic‐assisted LDED (UA‐LDED ...
Yuzhou Zeng +9 more
wiley +1 more source
Gaoya dianqi, 2003 研究了放电声发射波检测中用小波分析进行信号提纯与消噪的实现问题,包括选择小波、选择小波分解层数、提取有用频段的小波系数、小波消噪过程、小波消噪中的阈值选取,以及对提纯的放电声发射波进行小波消噪等。两组实测信号的小波提纯与消噪结果证明了信号提纯与消噪的优越性。
王成江, 舒乃秋
doaj
Phenology drives asymmetric responses of ecosystem productivity stability to warming and cooling
Functional Ecology, Volume 40, Issue 9, Page 2959-2971, September 2026.Read the free Plain Language Summary for this article on the Journal blog. Abstract Ecosystem productivity stability is a key indicator of ecosystem functioning under climate change, but the role of cooling periods in increasingly variable climates remains poorly resolved.
Yao Wei +11 more
wiley +1 more source
Dianci bileiqi, 2012 母小波的选择对提取绝缘子泄漏电流中的突变成分具有重要作用。根据对大量泄漏电流信号的分析,得出小波分解后的细节的能量越集中,所采用的母小波越适合提取泄漏电流的突变成分。据此采用熵作为评价母小波优劣的方法,并给出了泄漏电流熵的计算过程,进而给出了选择最佳母小波的步骤。以高压试验室采集到的泄漏电流为分析对象,以db（Daubechies）小波系为待选母小波集合,根据各小波分解泄漏电流之后的熵值,确定了db2小波为最佳母小波。采用不同母小波对泄漏电流进行了分析,结果显示db2小波优于其他小波。从而得出结论 ...
黄建才, 朱永利
doaj
Journal of Sociolinguistics, Volume 30, Issue 4, Page 452-465, September 2026.ABSTRACT This study investigates how ordinary Taiwanese netizens perform linguistic authority by policing others’ use of Mainland Chinese expressions in everyday online interactions not originally intended to be political and how such policing is subsequently supported, resisted, or (de)legitimized in the context of Taiwan–China relations. Three orders
Hsi‐Yao Su
wiley +1 more source
四川大学学报. 自然科学版, 2010 选取几种不同的小波函数利用连续小波变换(CWT)对同一图像进行处理,比较不同小波函数的小波脊系数幅值信息和恢复图像的效果,得出可以参考小波脊系数幅值表现的方法来选取合适的小波函数的结论.计算机模拟和实验也证实了该方法的正确性.
许罗鹏, 陈文静, 赵玥, 蔡义祥
doaj