Results 11 to 20 of about 19,101 (258)

Modeling mammal response to fire based on species’ traits

open access: yesConservation Biology, Volume 37, Issue 4, August 2023., 2023
Abstract Fire has shaped ecological communities worldwide for millennia, but impacts of fire on individual species are often poorly understood. We performed a meta‐analysis to predict which traits, habitat, or study variables and fire characteristics affect how mammal species respond to fire.
Christopher A. Pocknee   +3 more
wiley   +1 more source

Spatial mismatch between wild bee diversity hotspots and protected areas

open access: yesConservation Biology, Volume 37, Issue 4, August 2023., 2023
Abstract Wild bees are critical for multiple ecosystem functions but are currently threatened. Understanding the determinants of the spatial distribution of wild bee diversity is a major research gap for their conservation. We modeled wild bee α and β taxonomic and functional diversity in Switzerland to uncover countrywide diversity patterns and ...
Joan Casanelles‐Abella   +4 more
wiley   +1 more source

MsaH2A.W is identified response to salt tolerance in Miscanthus sacchariflorus

open access: yesGCB Bioenergy, Volume 15, Issue 8, Page 1058-1073, August 2023., 2023
To study the underlying genetic basis of Miscanthus adaptation to salt stress, the transcriptome variations of Miscanthus sinensis, Miscanthus sacchariflorus and their hybrid were analysed using RNA‐seq technology under salt treatment. According to the expression pattern of known salt‐tolerant genes, a histone variant gene MsaH2AW of M.
Ting Yu   +12 more
wiley   +1 more source

Time‐lagged effects of habitat fragmentation on terrestrial mammals in Madagascar

open access: yesConservation Biology, Volume 36, Issue 5, October 2022., 2022
Abstract Biodiversity is severely threatened by habitat destruction. As a consequence of habitat destruction, the remaining habitat becomes more fragmented. This results in time‐lagged population extirpations in remaining fragments when these are too small to support populations in the long term.
Maarten J. E. Broekman   +5 more
wiley   +1 more source

局部场地地震动高频衰减系数估计模型

open access: yesDizhen xuebao, 2023
采用随机有限断层法进行地震动模拟时,选用合理的参数描述特定局部场地近地表高频衰减特征,对评价地震动模拟结果的正确与否具有重要的实践意义。 在工程场址地震动参数预测中,如何快速确定参数的取值,是实际应用中亟需解决的问题。首先对场地高频衰减系数κ0与平均剪切波速vS30的相关性进行了分析;然后,基于国内外学者计算得到的546个κ0系数,采用一定时窗内的κ0均方根值,讨论其随平均剪切波速vS30增加的变化趋势。 结果表明,虽然κ0具有明显的区域差异性,但其均方根值随着vS30的增大呈现出逐渐减小的趋势 ...
Ziping Lang   +4 more
doaj   +1 more source

基于上层大气数值模型的X射线传输特性

open access: yesKongjian kexue xuebao, 2023
核爆炸的大部分能量是以X射线形式释放的,研究X射线辐射特性对于天基核爆事件监测,当量反演都具有一定参考价值。根据核爆炸X射线能谱特性,构建了黑体辐射模型;根据NRLMSIS大气模型成分数据和高度密度数据,构建大气分层数值模型,并结合NIST数据库,构建分层大气质量吸收系数模型,提高了大气模型与大气质量吸收系数模型准确度。使用数值模拟程序对X射线在大气中的传输特性进行研究,模拟在临近空间高度核爆炸产生的X射线经过大气吸收后的能谱特性以及不同海拔高度点位的能注量。结果表明,在检测点高度恒定的情况下 ...
吕 致辉   +4 more
doaj   +1 more source

Numerical study on the morphology and fractal dimension of two-dimensional magnetic clusters(二维磁性团簇形貌及其分形维数的数值研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2008
在扩散限制凝聚(DLA)模型基础上,采用Monte Carlo方法模拟了具有幂次相互作用的磁性粒子动力学凝聚过程.重点研究了在不同幂指数α值下团簇的形貌及其分形维数Df随耦合参数βC的演化规律.模拟结果表明:对于较大的α值,即α=5时,团簇形貌随βC的变化较小,其分形维数Df 一般在1.60~1.70;而随着α值的减小,团簇形貌随参数βC有一明显的演化过程,在模拟范围内,分形维数Df在1.20~1.95.
WANGFeng-fei(王凤飞)   +2 more
doaj   +1 more source

流固边界耦合介质高阶有限差分地震正演模拟方法

open access: yesDizhen xuebao, 2018
本文针对流固边界耦合介质提出了一种高效、稳定的正演数值模拟方法. 首先,从一阶位移-应力弹性波方程出发,基于海底流固边界的位移和应力的连续性条件,采用三次样条海底界面定量表征方法,推导出不规则海底界面下流固边界耦合介质中的地震波波动方程;其次,通过空间微分的高阶差分格式提高数值模拟的空间精度,并结合已推导的地震波波动方程,将四阶时间微分转换至高阶空间微分,进一步提高了数值模拟的时间精度;最后,在与标量波波动方程数值模拟结果对比分析的基础上,分别利用简单的水平层状模型和复杂海底模型 ...
Guochen Wu   +3 more
doaj   +1 more source

鱼饲料对铜绿微囊藻和斜生栅藻生长、种间竞争的影响

open access: yesHaiyang yu huzhao
由于湖泊水库等养殖水体中鱼饲料等营养物质的投加,导致藻类大量繁殖并严重威胁养殖水体生态平衡,了解养殖水环境中藻类之间的竞争特点和生存策略对揭示水华暴发机制具有重要意义。实验采用无氮磷的M-11培养基,加入鱼饲料制备成改进的M-11培养基,以铜绿微囊藻和斜生栅藻为实验对象,设定培养条件为:白天3 000 lx,28 ℃,12 h;夜间0 lx,20 ℃,12 h。通过测定藻细胞密度和氮磷营养盐浓度,并应用改进的藻生长动力学方程和竞争方程 ...
李 高成   +5 more
doaj   +1 more source

基于数值模拟和决策树回归的金属切削力学性能预测

open access: diamond应用数学和力学
Yijin CHENG   +3 more
openalex   +2 more sources

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