Results 41 to 50 of about 5,109 (161)
, 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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Shuitu 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
Impacts of mangrove vegetation on macro-benthic faunal communities [PDF]
, 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
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New Phytologist, Volume 247, Issue 2, Page 504-517, July 2025.Summary Repetitive DNA is a feature of all organisms, ranging from archaea and plants to humans. DNA repeats can be seen both in coding and in noncoding regions of the genome. Due to the recurring nature of the sequences, simple DNA repeats tend to be more prone to errors during replication and repair, resulting in variability in their unit length ...
Sridevi Sureshkumar +3 more
wiley +1 more source
Zhongguo 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
Integrative Conservation, Volume 4, Issue 2, Page 231-245, June 2025.Plant order‐level Sankey plot illustrating plant use of ethnolinguistic groups for key disease types based on organ systems and use. Each node represents the strength of its interaction or usage. ABSTRACT Many human populations rely on natural remedies for health and healing, with traditional medicinal plants playing a vital role in diverse ...
Krizler C. Tanalgo +15 more
wiley +1 more source
Shuitu Baochi Xuebao, 2007 利用标准样方法研究了川西最主要的两种退耕还林植被(苦竹林和桦木林)在恢复初期生态系统碳储量、碳素密度以及空间分配特征.结果表明:(1)苦竹不同器官碳素密度为0.348 5～0.518 6 gC/g,桦木不同器官碳素密度为0.451 9～0.513 7 gC/g;(2)苦竹林林下枯落物的碳素密度为0.341 7 gC/g,桦木林林下枯落物的碳素密度为0.395 3 gC/g;(3)不同植物器官的碳储量分配与各器官的生物量显著相关.苦竹林分中竹秆生物量占48.87%,其碳储量占53.06 ...
黄从德, 张健, 邓玉林, 杨万勤
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Effectiveness of protected areas in the Caucasus Mountains in preventing rangeland degradation
Conservation Biology, Volume 39, Issue 3, June 2025.Abstract As land use intensifies globally, it increasingly exerts pressure on protected areas. Despite open, nonforested landscapes comprising up to 40% of protected areas globally, assessments have predominately focused on forests, overlooking the major pressures on rangelands from livestock overgrazing and land conversion.
Arash Ghoddousi +12 more
wiley +1 more source
, 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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Assessing Closed Hydroponic Subsystems for Batavia Lettuce Growth Under Different Planting Densities
World Water Policy, Volume 11, Issue 2, Page 427-438, May 2025.ABSTRACT Hydroponic systems have the potential to be sustainable and alternative methods for food production that confer advantages of high production and better control of growth. However, only a few studies have focused on leafy vegetable growth in different subsystems and environmental variables.
Demet Çekin +6 more
wiley +1 more source