Results 21 to 30 of about 16,633 (215)

压力罐消解能谱法测定海洋生物中的210Po

open access: yesHe jishu
海产品中的210Po是人体内照射剂量的主要来源,准确测定海洋生物中210Po的比活度尤为重要。本文建立了海洋生物中210Po的压力罐消解-α能谱检测方法。该方法以209Po为产额示踪剂,海洋生物样品经压力罐消解处理后,在盐酸体系中用镍片自沉积方法分离210Po,使用α能谱仪进行测量。在本方法测定条件下,标准物质的测定结果与标准值一致,相对标准偏差为9.0%,全程放化回收率为92.9%~98.6%,方法检出限为0.18 Bq·kg-1。该方法操作简便高效、环境友好、回收率高且测定结果准确可靠 ...
林 静   +3 more
doaj   +1 more source

Floristic analysis of the seed plants from Yandang Mountain of Yueqing, Zhejiang(浙江乐清雁荡山种子植物区系分析)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2018
在文献查阅、野外调查和标本鉴定的基础上,对浙江乐清雁荡山种子植物区系特征进行了统计分析,得到:(1)区域内共有野生种子植物732种(含种下类群),隶属147科、433属;科、属水平显示出多样性,含1个种的科和属分别占总科数和总属数的41.5%和67.9%. (2)科的分布区类型中,热带成分有64科,占总科数的42.9%,温带成分共36科,占24.6%;属的分布区类型中,热带成分和温带地理成分分别占总属数的49.1% 和50.9%,泛热带分布及其变型所占比例最大,为24.1%.
CHENWeijie(陈伟杰)   +3 more
doaj   +1 more source

广东中山水栖寡毛类区系调查 [PDF]

open access: yes, 2008
中山市位于珠江三角洲中南部,区内分布江河、溪流、水库、池塘等多种水体,迄今未见对该地区水栖寡毛类区系的研究报道。通过2005年6月和12月两次调查,记述中山市水栖寡毛类31种,隶属4科16属,包括1个国内新纪录种即扇形管盘虫(Aulophorus flabelliger)以及19个广东省新纪录种。区系分析表明 ...
崔永德   +3 more
core  

Life Stage‐Specific Genetic Diversity and Landscape Characteristics Collectively Influence Genetic Recovery in Pometia pinnata Population 生活史阶段特异的遗传多样性与景观特征对番龙眼种群遗传恢复的协同影响

open access: yesIntegrative Conservation, EarlyView.
Pometia pinnata demonstrated life‐stage‐specific genetic responses to landscape features, with asymmetric gene flow patterns and population recovery following historical bottlenecks, revealing complex topographic and demographic influences on forest genetic structure.
Madhuparna Chatterjee   +5 more
wiley   +1 more source

香溪河小水电的梯级开发对浮游藻类的影响 [PDF]

open access: yes, 2007
以香溪河干流上5个连续的小水电站为对象,于2005年10月20—22日分别对其浮游藻类和主要理化指标进行研究.结果表明:硅藻占绝对优势(95.54%),其中,线性曲壳藻(Achnanthes linearis)、披针曲壳藻椭圆变种(A.lanceolatavar.elliptica)、扁圆卵形藻(Cocconeisplacentula)为绝对优势种,其平均相对丰富度分别为23.96%、18.62%和12.48%;所有样点的平均藻类密度为6.29×105ind.L-1,最高为1 ...
傅小城   +5 more
core  

Urbanization and Seasonality Increase Introduced Plant Consumption by the World's Southernmost Parrot 城市化与季节性增加了全球最南端鹦鹉对引入植物的取食

open access: yesIntegrative Conservation, EarlyView.
Urbanization may alter bird foraging. Austral Parakeets (Enicognathus ferrugineus) in Patagonia rely on introduced plants in urban areas, especially in winter, despite preferring natives in the wild. This seasonal reliance on introduced species highlights urbanization trade‐offs and underscores the need to manage green areas with native plants to ...
Rocío Bahía   +2 more
wiley   +1 more source

A Preliminary Assessment of Noise‐Related Impacts From the Urban‐Invasive Johnstone's Whistling Frog (Eleutherodactylus johnstonei) 城市入侵物种约翰斯通鸣蛙 (Eleutherodactylus johnstonei) 引起的噪声影响初步评估 Una evaluación preliminar de los impactos relacionados con el ruido de la rana silbadora de Johnstone (Eleutherodactylus johnstonei), especie urbana invasora

open access: yesIntegrative Conservation, EarlyView.
The Johnstone's whistling frog is an invasive species whose loud night‐time calls may affect human health and well‐being. Our study in Cali, Colombia, combined fieldwork and online surveys to assess its urban occupancy, density, and potential health impacts.
Rubén Darío Palacio, Sumana Goli
wiley   +1 more source

安氏新银鱼(Neosalanx anderssoni)性别特异性位点筛选及性别鉴定方法开发

open access: yesHaiyang yu huzhao
安氏新银鱼是我国重要的小型经济鱼类物种,具有较高的经济价值。但目前缺乏一种快速、经济有效的性别鉴定方法,极大地阻碍了其性别决定分子机制、性染色体演化历程的研究和水产育种与养殖技术方面的生产实践。本研究通过比较安氏新银鱼雌性与雄性的全基因组重测序数据,发现雌雄之间存在一个显著差异的基因组区域(chr02: 2 798 574~5 434 239 bp)。基于测序深度差异分析筛选得到3个雌性特异性片段,长度分别为10 bp、167 bp和53 bp。在长为167 bp的雌性特异性位点附近设计引物 ...
王 心悦   +4 more
doaj   +1 more source

Vulnerability Assessment of Coastal Zone in China under the Background of Climate Change [PDF]

open access: yes, 2015
气候变化与自然和人类社会系统有着密不可分的关系。气候变化所引起的极端天气、海平面上升、冰川消融、生态系统破坏、旱涝灾害等给自然生态系统和社会经济系统平衡带来了严峻的挑战,严重的威胁着人类的生命财产安全。研究分析中国海岸带脆弱性,对完善我国海岸带脆弱性评估方法和指标体系,对我国海岸带管理及制定应对气候变化的战略决策具有重要的现实意义和学术价值。本论文对海岸带脆弱性评估理论进行了系统研究,在此基础上建立了海岸带脆弱性评估的方法和指标体系,并利用InVEST模型和ArcGIS软件对中国海岸带脆弱性进行了评估 ...
孙晓萌
core  

Sun Bear Ecology and Conservation: Multiscale Habitat Associations in Southeast Asia 马来熊的生态与保护:东南亚地区的多尺度生境关联研究

open access: yesIntegrative Conservation, EarlyView.
We collated detections of the sun bear from new and previously published camera trap studies across its range. We then analysed these detections at two different spatial scales to assess the habitat associations and diel activity of this species. We found that the sun bear is tolerant to moderate habitat disturbances. ABSTRACT Degraded tropical forests,
Alexander Hendry   +5 more
wiley   +1 more source

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