Results 11 to 20 of about 16,500 (146)
Dizhen xuebao, 2020 为了探索大容量气枪震源在探测区域结构以及在内陆水体进行水陆联测的可行性与有效性，2015年在安徽铜陵完成了长江航道走航激发、陆地接收反射波的“地学长江计划”铜陵段试验。本文从试验观测系统、共中心点分布、覆盖次数以及单炮数据属性等方面综合分析了大容量气枪震源陆地反射试验结果的影响因素。试验结果表明：① 大容量气枪震源在内陆水体激发能够用于地壳结构的探测；② 在水陆联测勘探中，根据目标层段合理设计反射角，能够有效地解决小炮检距反射角不足、大炮检距能量弱的问题；③ 在进行弯线数据采集时，需要对观测系统进行设计，
Hongwei Wang +5 more
doaj +1 more source
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
Classifier of silicon content in hot metal based on support vector machines(基于支持向量机的高炉铁水硅含量多类别分类)
Zhejiang Daxue xuebao. Lixue ban, 2007 支持向量机是基于统计学习理论发展而来的一种机器学习算法，本文介绍了非线性软间隔分类机、最小二乘分类机和加权最小二乘分类机的算法.以山东莱钢1号高炉在线采集数据作为应用案例，使用C-均值算法对[Si]做聚类分析将其分成5类，改进M-ary分类方法实现对铁水硅质量分数[Si]的多类别分类，并对各分类机的性能作出评价.
JIANLing(渐令) +2 more
doaj +1 more source
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
Food and Energy Security, Volume 15, Issue 2, March/April 2026.ABSTRACT Net photosynthetic rate (Pn) serves as a key indicator for evaluating plant growth and yield. In order to explore an effective method for monitoring winter rapeseed Pn using unmanned aerial vehicle (UAV) multispectral technology, the winter rapeseed was taken as the research object and the multispectral images were obtained through UAVs in ...
ChengYang Ni +7 more
wiley +1 more source