Results 21 to 30 of about 6,221 (109)
不同种植密度条件下两种穗型冬小麦品种根际土壤酶活性的动态变化
在大田试验条件下,研究了2种穗型冬小麦品种在不同种植密度条件下根际土壤酶活性的动态变化。结果表明,随着生育时期的推进,两种穗型冬小麦品种根际土壤蛋白酶、过氧化氢酶和脲酶活性均呈先增高后降低的单峰曲线变化,拔节期和抽穗期活性较高,返青期和开花期活性则较低。不同种植密度条件下,豫麦49—198系根际土壤蛋白酶、脲酶活性均随密度增加呈先增高后降低的变化趋势,而过氧化氢酶活性表现不明显;兰考矮早八3种根际土壤酶活性随密度增加呈先降低后增高的变化趋势。不同密度水平下3种酶活性的方差分析表明,蛋白酶 ...
查菲娜 +5 more
doaj +2 more sources
为探究不同植物根-土复合体抗剪强度的差异性及各因素对其的影响程度, 选取汶川县针叶林、阔叶林、灌丛、草地4种不同植被覆盖区为研究区, 通过野外制取16种优势植物根-土复合体和无根裸土原状试样并开展室内快剪试验。分析了汶川县典型植物根系对土体抗剪强度和抗变形能力的增强作用, 运用灰色关联法分析影响复合体抗剪强度的因素。结果表明: (1)16种植物根系均能在一定程度上提高土体抗剪强度和抗变形能力, 且主要通过提高土体黏聚力增强其抗剪强度; 根-土复合体黏聚力均大于裸土, 其增幅为6.09%~153.27%,
孙庆敏 +4 more
doaj
Dimensional Assembly Engineering of Ce‐MOF Interfaces for Selective Recognition of Phytic Acid
ABSTRACT Selective molecular recognition is central to chemical sensing yet discriminating structurally similar molecules at complex interfaces remains challenging. Traditional strategies based on tuning size, charge, or binding‐site chemistry often suffer from limited flexibility.
Qiang Miao +7 more
wiley +1 more source
为探讨东北雨养区玉米生长状况和田间水分对种植密度和地膜覆盖的响应,2015年在沈阳农业大学水利学院试验场设置了低(67 500株/hm2)、中(82 500株/hm2)、高(97 500株/hm2) 3个种植密度水平和覆膜/裸地2种方式的玉米田间试验,据试验结果分析了土壤水分、玉米根系及其产量变化。结果表明:(1)在0—20 cm土层中,整个生育期内,覆膜对于低密度处理的土壤田间含水率影响显著 ...
陈志君 +4 more
doaj
ABSTRACT Additive manufacturing, commonly referred to as three‐dimensional (3D) printing, provides the geometric freedom and multi‐material integration needed to build soft medical robots for minimally invasive interventions, prosthetics, and rehabilitation.
Yao Wang +5 more
wiley +1 more source
目的为探讨不同种植密度下植物根系的固土减蚀效应。方法以黄土高原典型草本植物黑麦草(Lolium perenne)和紫花苜蓿(Medicago sativa)为研究对象,采用100、300、500株/m2 3个种植密度,研究不同种植密度下植物根系生长对土壤侵蚀阻力的影响。结果试验期内,植物根系特征整体呈先快速增长后缓慢下降趋势,黑麦草和紫花苜蓿的根系特征分别在中、高密度种植样地生长最佳。在根系生长的驱动下,土壤有机质呈不断增长趋势,黑麦草和紫花苜蓿样地的土壤有机质分别在中、高密度种植下增量最大,分别增长2.
刘均阳, 周正朝, 韩玮霄
doaj +2 more sources
为了推进根系固土机制的定量研究,在前期边坡调查和植物筛选的基础上,人工种植了百喜草、假俭草、狗牙根3种常见的护坡植物,根据各深度下原状根-土复合体干密度、含水率和质量含根量等物理性质指标,设计了重塑根-土复合体直剪试验方案,实施了3种植物原状和重塑根-土复合体的直剪试验。结果表明:3种原状根-土复合体的抗剪强度在各级法向压力作用下均随含根量的增加而逐渐增大;3种原状根-土复合体的黏聚力和内摩擦角均随深度的增加而减小;3种植物根系在相同的土体状态下对黏聚力的影响排序为狗牙根>百喜草>假俭草 ...
陈 +5 more
doaj
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
通过野外取样和室内分析,初步研究了科尔沁沙地两种生物结皮在干、湿两种处理下土壤种子库种类组成、密度以及物种多样性等特征.结果表明①科尔沁沙地藻结皮和苔藓结皮土壤种子库的总密度为干旱藻结皮<湿润藻结皮<干旱苔藓结皮<湿润苔藓结皮.两种结皮上种子库的数量存在显著差异,对于干、湿处理的两种结皮,苔藓结皮上种子库的总密度均大于藻结皮上种子库的总密度;②两种生物结皮在干旱、湿润两种处理中共出现了6科、15种植物,种子库的组成以一年生草本植物、中生植物为主,二者百分比均超过76%;③在干旱藻结皮、湿润藻结皮 ...
郭轶瑞 +4 more
doaj +2 more sources
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

