Results 11 to 20 of about 28,720 (141)

Planar cubic Cardinal spline with tension parameter and boundary condition optimization(优化张力参数与边界条件的平面三次Cardinal 样条)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2019
当数据点给定时,三次Cardinal 样条的张力参数和边界条件均为自由变量,因此可对这些自由变量进行优化,以得到满足某种特定要求的最佳三次Cardinal 样条。讨论了如何通过优化张力参数与边界条件使得构造的平面三次Cardinal 样条尽可能光顺。首先,分析了三次Cardinal 参数样条曲线形状的影响因素;然后,利用曲率变化能极小对三次Cardinal 参数样条曲线的张力参数与边界条件进行优化,获得张力参数与边界条件的唯一解; 最后,给出了对应三次Cardinal ...
LIJuncheng(李军成)   +2 more
doaj   +1 more source

Local Ecological Knowledge Reveals the Distribution of Cryptic Nocturnal Wildlife 局域生态知识揭示隐秘夜行野生动物的分布

open access: yesWildlife Letters, EarlyView.
Many nocturnal animals are difficult to study because they are rarely seen, including nocturnal primates, galagos and pottos, in West Africa. Working with over 600 people in 52 villages in southern Guinea‐Bissau, we found that communities frequently recognized galagos by their red eyeshine and distinctive calls, while pottos were not known.
Chloe Chesney   +6 more
wiley   +1 more source

Wings of Change: Motivations, Challenges, and Environmental Concerns Among Birdwatchers 变革之翼:观鸟者的动机、挑战与环境关切

open access: yesWildlife Letters, EarlyView.
Birdwatching in Nepal has high potential to support avain biodiversity and tourism. Conservation was identified as the primary motivation for birdwatching, followed by enjoyment and achievement purposes. Health/wellbeing benefits, social and economic factors showed moderate representation, whereas academic motivation played a relatively minor role ...
Kamal Raj Gosai, Hem Bahadur Katuwal
wiley   +1 more source

Leaf C:P ratio as a universal indicator of photosynthesis in subtropical woody species: Stoichiometric thresholds and metabolic trade‐offs

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometric ratios of carbon (C), nitrogen (N) and phosphorus (P) serve as important indicators for assessing nutrient balance in forest ecosystems, but their relationships with photosynthetic dynamics require deeper characterization.
Minghao Chen   +9 more
wiley   +1 more source

Flexible parental care in a songbird correlates with sex‐specific responses to seasonal phenology, mating opportunity and reproductive success

open access: yesJournal of Animal Ecology, EarlyView.
This population‐comparative study reveals that male and female parents respond differently to social and ecological conditions. This sex‐specific responsive strategy is related to the incongruent parental care systems across populations in Chinese penduline tits.
Jia Zheng   +5 more
wiley   +1 more source

The collective application of shorebird tracking data to conservation

open access: yesConservation Biology, EarlyView.
Abstract Addressing urgent conservation issues, such as the drastic declines of North American migratory birds, requires creative, evidence‐based, efficient, and collaborative approaches. The abundance of over 50% of monitored North American shorebird populations has declined by over 50% since 1980. To address these declines, we developed a partnership
Autumn‐Lynn Harrison   +71 more
wiley   +1 more source

参数表以及模块化编程在中药发药机PLC控制程序中的应用

open access: yes四川大学学报. 自然科学版, 2008
在介绍基于S7-200 PLC编程控制中药配方颗粒自动发药机工作的基础上,分析了参数表以及模块化编程在中药发药机PLC控制程序中的应用.参数表是指将大量参数以表的方式存储到PLC的变量存储器中,在PLC功能模块中通过指针引用来实现对参数表的访问.只读参数表也称为静态参数表,可以通过程序修改参数值的称为动态参数表.经实验证明,参数表以及模块化编程的应用大大简化了参数初始化过程,并使得PLC控制程序逻辑结构清晰,提高了程序的可读性与可维护性.
张璐, 李志蜀
doaj  

The shape-adjustable transition curves and surfaces with parameter direction preserving(保参数方向的形状可调过渡曲线与曲面)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2019
针对保参数方向构造过渡曲线曲面方法的不足,构造了任意参数曲线曲面间既保持参数方向又具有形状可调性的C1 与C2 连续过渡曲线曲面。首先,基于2 类带1 个自由参数的调配函数,分别构造满足C1 与C2 连续的过渡曲线,并讨论基于能量优化模型的最佳过渡曲线构造问题; 然后,将所提出的方法推广到过渡曲面的构造。实例结果表明,2 被过渡曲线曲面为任意参数曲线曲面时,利用该方法构造的过渡曲线曲面不仅与2 被过渡曲线曲面的参数方向保持一致,而且可利用所带的自由参数对其形状进行调整。通过能量优化模型确定自由参数的取值,
LIJuncheng(李军成)   +2 more
doaj   +1 more source

Comprehensive framework for assessing and optimizing existing research networks

open access: yesConservation Biology, EarlyView.
Abstract Conservation, monitoring, and research networks, or collections of ecological research sites unified under a common mission of data collection or a research mission, are essential infrastructure for understanding large landscapes. However, most networks developed opportunistically over decades rather than through systematic design, creating ...
Alyson East   +2 more
wiley   +1 more source

适用于全周期结构的速度脉冲型地震动强度表征参数研究

open access: yesDizhen xuebao, 2019
鉴于传统的地震动强度表征参数(IM)不能有效地反映速度脉冲型地震动的破坏特征,需要研究能够在全周期段内表征速度脉冲型地震动强度的参数。本文首先从NGA-West2强震数据库中选取了236条速度脉冲记录,分析了42种地震动参数之间的相似性和相关性,初步给出了速度脉冲型地震动强度的表征参数;其次,利用单自由度体系动力时程分析方法,研究了不同延性μ条件下速度脉冲型地震动强度表征参数与最大非线性位移um之间的相关性系数随周期T的变化特征 ...
Xiaofen Zhao   +3 more
doaj   +1 more source

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