Results 11 to 20 of about 16,027 (131)
Dizhen xuebao, 2018 为探究地震观测中地震计检测到的噪声和信号强度均受其布设深度的影响，本文首先对CPUP和LPAZ两台站布设的不同深度地震计所得到的数据进行噪声水平和地震信号对比；其次采用对比功率谱密度的方法对两台站不同通道采集到的不同时段的噪声数据进行分析；最后比较两台站不同通道采集到的整月数据的噪声幅值、信号幅值、信噪比特征。结果显示：深度较大的通道，其噪声功率均值较小；当事件信号到来时，较深通道的地震计检测到的信号和噪声幅值比较浅通道均有所减小，在信号和噪声幅值均减小的共同影响下，信噪比有一定程度的变化 ...
Ayao Zhang +6 more
doaj +1 more source
Jianzhu Gangjiegou Jinzhan, 2023 基于支持向量机的结构损伤识别方法建立在训练和测试数据同概率分布的假设上，必须对每个结构分别收集训练数据和标签并训练模型以识别损伤。损伤结构的训练数据和标签难以收集，导致支持向量机方法在结构损伤识别中难以实施。提出一种基于领域自适应支持向量机的跨域损伤识别方法，将在有损伤标签结构（源结构）上训练的支持向量机推广到无损伤标签结构（目标结构）的损伤识别中。该方法首先提取结构的多阶固有频率变化率作为损伤特征构建训练数据；然后，推导最小化边缘分布差异与最小化联合分布差异的迁移学习方法 ...
李佐强 +6 more
doaj
Soil Quality Assessment of Five Typical Forest Stands in the Dianchi Lake Basin based on MDS [PDF]
[Objective] Soil quality is a critical indicator of ecosystem health and sustainable land management. [Methods] Key soil quality indicators (e.g., organic matter, total nitrogen, available nitrogen, capillary porosity, and pH) were identified through ...
HUANG Shuai +4 more
core +1 more source
Gaoya dianqi, 2020 针对真空断路器的可靠性研究问题,对12 kV永磁操动式真空断路器做了寿命试验。将采集到的试验数据用Weibull变换进行预处理,变换后的数据在普通坐标系内接近于直线,基于图形法可接受二参数Weibull分布作为拟合模型;采用最小二乘法计算确定了Weibull分布模型的具体参数;最后,在小样本试验数据的情况下,采用针对Weibull分布的Mann检验方法进行模型检验。结果表明,真空断路器的寿命数据符合二参数Weibull分布模型,并计算得到了模型的可靠性评价指标和真空断路器的平均寿命。
穆艳 +4 more
doaj
Evaluation of the Effectiveness of Soil Improvement Measures in Apple Orchards on the Loess Plateau: A Meta-Analysis [PDF]
[Objective] Soil acidification, structure and fertility degradation and poor water-holding capacities are common problems in the apple orchard on the Loess Plateau, effective soil improvement techniques are crucial for enhancing soil quality, and ...
DUAN Shunxia +3 more
core +1 more source
Soil Preferential Flow Characteristics in Coal Mine Subsidence Area under Different Rainfall Duration [PDF]
[Objective] Research on the preferential flow characteristics triggered by cracks in coal mining subsidence areas can provide support for scientific and rational development of water resource management and ecological management practice in the mining ...
DAI Bin +4 more
core +1 more source
Conservation Biology, Volume 40, Issue 1, February 2026.Abstract Exploring heat tolerance and acclimation capacity can provide an effective approach to evaluating species’ sensitivity to extremely high temperatures due to climate warming. Despite some work on amphibian and reptile thermophysiological adaptation, related questions remain. We reviewed the literature to provide a synthesis of worldwide data on
Zijian Sun +8 more
wiley +1 more source
Extent of threats to marine fish from the online aquarium trade in the United States
Conservation Biology, Volume 40, Issue 1, February 2026.The global marine aquarium hobby is a multibillion‐dollar industry, largely driven by demand from the United States. Much of this trade occurs online. We web scraped 4 major US‐based e‐commerce platforms selling marine aquarium fish to determine the retail price and source (wild capture, aquaculture, or both) of 13 families of ray‐finned marine fish ...
Bing Lin +6 more
wiley +1 more source
International Journal of Applied Linguistics, Volume 36, Issue 1, Page 652-666, February 2026.ABSTRACT Given the importance of the linguistic landscape in language learning, the digital linguistic landscape (DLL) has emerged as an important multimodal input resource. However, few studies have been conducted to explore the antecedent and predictive effect of the DDL on L2 writing. To address this gap, the study attempted to conceptualize the DLL
Zi Yang, Lawrence Jun Zhang
wiley +1 more source