Results 41 to 50 of about 5,920 (160)

膜下滴灌条件下绿洲棉田土壤水分运动数值模拟 [PDF]

open access: yes, 2007
应用非饱和土壤水运动理论,建立膜下滴灌条件下土壤水分运动二维数值模拟模型,研究了田间层状土壤在膜下滴灌条件下土壤水分运动特征。应用不同小区不同灌水处理的实测值与模拟值进行对比,同时对模型做了精度分析,结果表明符合精度要求,这说明所建立的模型能客观地反映实际土壤条件下的水分运动情况。研究结果表明:土壤剖面30~40 cm粘土层使土壤水分运动具有很大的差异,0~30 cm变化明显,而40 cm以下土壤水分运动的变化较小。膜下滴灌应该采取灌水量小 ...
串志强, 方怡向, 盛钰, 赵成义
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Breeding report of a new table Phyllanthus emblica cultivar Lütianyougan [PDF]

open access: yes
Phyllanthus emblica L. is one of important fruit crops with both medicinal and edible values. Currently, fresh variety of P. emblica has high economic benefit and great development potential. Herein, Lütianyougan, a new table variety of P.
LAI Duo   +5 more
core   +1 more source

Assessing limits of sustainable seed harvest in wild plant populations

open access: yesConservation Biology, Volume 39, Issue 5, October 2025.
Abstract Seed harvesting from wild plant populations is key for ecological restoration, but it may threaten the persistence of the source populations. Consequently, several countries have set guidelines limiting the proportions of harvestable seeds. However, these guidelines are inconsistent and lack a solid empirical basis.
Anna Bucharova   +3 more
wiley   +1 more source

Impacts of mangrove vegetation on macro-benthic faunal communities [PDF]

open access: yes, 2013
大型底栖动物是红树林生态系统的重要组成部分,从红树林大型底栖动物种类、红树林与其周边生境大型底栖动物群落的比较,以及生境变化对动物群落的影响等方面阐述了红树林植被与大型底栖动物群落的关系。从物种数量上看,软体动物和甲壳类动物构成了红树林大型底栖动物的主要部分。影响大型底栖动物分布的环境因素包括海水盐度、潮位和土壤特性等,但在小范围区域,林内动物的分布更多地与红树林植被特性和潮位有关。因此,由于红树林植被破坏或者恢复引起的生境变化,将导致大型底栖动物群落和常见物种种群的变化,尤其对底上动物影响明显 ...
余丹, 叶勇, 陈光程, 陈彬
core   +1 more source

影响口腔种植成功的因素分析

open access: yesZhongguo shiyan zhenduanxue, 2015
口腔种植技术是在牙槽突内植入一人工装置并与颌骨结合,用以支撑和固位修复体,完成对缺牙的修复[1],其具有一定的复杂性。因此,如何确保口腔种植体修复成功是至关重要的。学者们主要从种植体植入后的动度、骨吸收量、骨密度的变化等方面对种植体成功与否进行评定[2]。1986年Albrektsson等学者确立种植体成功标准为:单个种植体无松动;X线检查种植体周围无明显的阴影透射区 ...
刘润喆, 王蕊
doaj  

云南多雨烟区增密减氮对烤烟产质量及养分利用率的调控效应

open access: yesShuitu Baochi Xuebao, 2020
为明确增密减氮对烤烟产质量及肥料利用率的调控效应。以烤烟品种"云烟105"为材料,研究种植密度(13 890,15 150,16 665株/hm2)和施氮水平(0,84,94.5,105 kg/hm2)及其互作对烤烟产质量及养分利用效率的影响。结果表明:适度增密减氮能显著提高烤烟肥料利用率、产量和产值,使烟叶总糖、还原糖、钾含量显著升高,总氮、烟碱含量降低,对水溶性氯无显著影响,烟叶化学品质更加协调。烟叶化学成分协调性及烤烟氮磷钾利用率显著受年份、密度、施氮及年份×施氮、密度×施氮、年份×密度 ...
余小芬   +10 more
doaj  

Promoting Conservation and Coexistence: The Case of Blackbucks (Antilope cervicapra L.) and the Bishnoi Community in Abohar, Punjab, India 促进保育与共存:以印度旁遮普邦阿博哈尔的黑羚 (Antilope cervicapra L.) 和比什诺伊社区为例

open access: yesIntegrative Conservation, Volume 4, Issue 3, Page 393-404, September 2025.
We studied the challenges in human‐wildlife coexistence in Abohar wildlife sanctuary and the surrounding landscape in Punjab, India. We found that the local people's unique intrinsic motivation for conservation and the traditional approaches to conservation are no longer sufficient.
Geethanjali Mariaselvam   +5 more
wiley   +1 more source

Studies on the Ecological Restoration of Mangroves - a Case Study in Xiamen [PDF]

open access: yes, 2008
本研究在全面分析国内红树林生态恢复的形势的基础上,针对厦门红树林生态恢复过程中存在的具体困难,从潮位、底质、有害生物等角度具体分析了厦门红树林生态恢复面临的困难。抓住影响红树植物苗木成活的关键因素:滩涂潮位太低,从成活率、生长、光合、营养积累、次生代谢物质等探讨了滩涂高程与红树植物苗木生长之间的关系;比较了不同种植模式(树种搭配、种植密度)等的生态恢复效果;探讨了红树林生态恢复过程中生态功能的变化。 1.研究了滩涂高程对红树林生态恢复的影响研究,从理论上和实践上明确了滩涂高程是决定红树林造林成败的关键 ...
何缘
core  

World‐wide impacts of climate change and nitrogen deposition on vegetation structure, composition, and functioning of shrublands

open access: yesNew Phytologist, Volume 247, Issue 3, Page 1117-1128, August 2025.
Summary Environmental changes and their effects are among the most pressing topics of today's ecological research. Shrublands, although widespread across the globe, remain understudied in this respect. We conducted a global meta‐analysis of 81 shrubland sites subjected to experimental warming, shifts in precipitation (e.g.
Daijun Liu   +11 more
wiley   +1 more source

人类神经干细胞的长期培养和传代 [PDF]

open access: yes, 2002
【目的】探讨人类神经干细胞的体外培养条件及其传代的方法。【方法】采用机械方法从胎脑中分离神经细胞, 应用N2 培养基进行培养, 碱性成纤维细胞生长因子(bFGF)和表皮生长因子(EGF)刺激细胞扩增;传统方法和对神经球切割 的方法进行传代培养;应用免疫组织化学染色对培养的细胞及其分化的细胞进行鉴定。【结果】从流产胎脑当中成功培养出 人类的神经干细胞, 培养条件下呈悬浮状态生长, 形成神经球, 绝大多数的细胞表达波形蛋白和Musashi1 两种神经干细胞的 标志物 ...
郑佳坤
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