Results 21 to 30 of about 13,790 (168)
Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
Pengpeng Wang +4 more
wiley +1 more source
Gaoya dianqi, 2020 配网变压器对电力系统的可靠、经济运行发挥着重要作用。过去,维护人员需要花费大量时间逐一检查配网变压器。而如今,随着电力用户电能数据采集系统的广泛部署,可提供有用的量测数据,并将其用于进一步的状态监视。因此,文中提出了一种用于配网变压器的基于数据驱动的异常状态监测数据采集算法,该算法可以及时向操作人员和维护人员发送异常状态警报。在所提的算法中,利用Spearman秩相关系数显示相电流间的相关度,其t统计量用于决定基于假设检验的确定数据采集是否存在异常情况。最后 ...
刘林青 +4 more
doaj
Jianzhu Gangjiegou Jinzhan, 2021 提出了一种新型自复位抗侧力模块,该模块主要由预应力钢边框和角部可更换阻尼器组成,将其配置于分层装配式钢框架中,可以实现结构系统的低残余变形与震后功能恢复。在自复位模块中,预应力钢边框主要提供初始刚度与恢复力,可更换阻尼器通过舌板受弯屈服耗能。该自复位模块的刚度、承载力和耗能系数可以独立调节,角部阻尼器具有分散耗能稳定、对连接抗力需求低、不影响窗口门洞布置、震后极易更换的特点。建立了该自复位抗侧力模块的刚度与承载力理论计算公式与数值模拟方法,并提出了配置自复位模块的分层装配式钢框架结构体系的性能化设计目标。
楚功崚, 王伟
doaj
Fatigue Life Prediction for Pre-Corroded Aluminum Alloy 2524based on Stress Severity Factor Method [PDF]
, 2013 腐蚀是金属结构失效的重要原因之一，航空结构的腐蚀损伤常常造成一些灾难性事故。机身结构用高强度铝合金处于含氯化物的腐蚀环境时很容易发生点腐蚀损伤。点蚀坑作为应力集中源，是裂纹容易萌生处，疲劳裂纹优先从腐蚀坑处萌生。腐蚀坑的应力集中情况跟腐蚀坑的深度、大小和形状等特征参数有关。因此，定量研究腐蚀坑特征参数与应力集中系数关系，用应力严重系数法对含腐蚀损伤结构进行疲劳寿命预测具有重要的研究价值。 本文主要研究了腐蚀坑特征参数与应力集中系数的关系及用应力严重系数法对腐蚀预损伤铝合金2524进行疲劳寿命预测。 首先，
赵伟
core
Reasonable width and control technology of narrow coal pillar in gob-side entry driving in deep-buried bump-prone coal seam [PDF]
Aiming at the problem of large deformation of surrounding rock and difficulty of control gob-side entry driving in deep coal seam, taking the setting of narrow coal pillar in gob-side entry driving in deep-buried bump-prone coal seam as the engineering ...
BAN Dingcheng +3 more
core +1 more source
Effects of parachute science on local research capacity 降落伞科学对当地研究能力的影响
Conservation Biology, EarlyView.Abstract Strengthening research capacity is essential to address the global biodiversity crisis. Yet, parachute science often undermines this goal, and its prevalence, costs, and benefits are unclear. We analyzed 13,502 publications on primate research that we extracted from Scopus (1960–2022) to evaluate the effects of parachute science on local ...
Li Yang +11 more
wiley +1 more source
Dizhen xuebao渝东南武隆地区志留系龙马溪组页岩储层发育，构造裂缝是页岩气运移和聚集的主控因素，而古构造应力场控制着构造裂缝的发育，对武隆地区页岩气的勘探开发具有较大影响。本文对武隆地区及周缘发育的节理进行分期配套处理，明确了武隆地区的古构造应力方向，同时通过岩石声发射实验计算得到了古构造应力的大小。在此基础上，利用ANSYS有限元软件建立了武隆地区志留系龙马溪组地层关键构造变形期的地质模型，并通过构造应力场的分析结果明确了该地区关键构造期的构造应力特征，以确定构造应力场数值模拟的边界条件，进而对构造应力场进行数值模拟。
Yizhen Pang +8 more
doaj +1 more source
大数据, 2023 面对新形势下的数据安全治理挑战，顺应数据安全领域的技术发展趋势，针对大型国企在数据安全治理实际应用中突出的关键权限人员识别问题，提出了一种基于图算法的关键权限人员识别技术。该技术可以发现系统中潜在的权限影响因素，并可从多个角度衡量不同含义的权重影响力，识别结果可解释性强。针对数据安全治理中的用户与实体行为异常检测问题，提出一种基于生成对抗网络的用户与实体行为异常检测方法，实验结果表明，所提方法的精确率、召回率和F1值的平均值均优于对比基线模型方法。设计开发了数据安全平台，平台在降低数据安全风险 ...
程伟, 马成, 凌捷
doaj +1 more source
Roof collapse accumulation and stress evolution characteristics of double-inclined mining in steeply inclined medium-thick coal seam [PDF]
The pseudo-inclined mining has limited capacity to reduce the inclination angle of working face, necessitating breakthroughs in longwall comprehensive mechanized mining methods for steeply inclined medium-thick coal seam with inclination angles exceeding
DU Yuqian +10 more
core +1 more source
Conservation Biology, EarlyView.Abstract There exists a growing suite of technologies that support significant and exciting progress in biodiversity conservation and research. Citizen scientist participation is common in this research and often focuses on data collection and labeling.
Joycelyn Longdon +5 more
wiley +1 more source