Results 11 to 20 of about 3,748,680 (147)
冻融是影响高寒地区土壤结构的重要物理因素,以青海湖流域高寒草甸作为研究对象,通过野外采集原状土柱、室内冻融循环模拟、CT扫描和图像解译等方法,研究冻融循环对高寒草甸冻胀丘和丘间地的土壤大孔隙结构特征的影响。结果表明,随着冻融循环次数的增加,高寒草甸冻胀丘和丘间地土壤大孔隙度均呈现"减小—增加—减小"的趋势,冻融循环对土壤大孔隙度的降低主要在第1次冻融循环内形成的,且大孔隙的平均等效直径、平均体积、平均分枝长度、分枝密度和节点密度的变化规律与大孔隙度变化规律基本一致 ...
赵云朵, 胡霞
doaj
ABSTRACT High‐entropy alloys (HEAs) have attracted considerable interest from researchers owing to their tunable chemical compositions, exceptional structural stability, and promising catalytic properties. However, their large‐scale application is often hindered by complex manufacturing techniques and poor durability.
Sheng Guo +9 more
wiley +1 more source
在岩溶作用下,喀斯特土壤—表层岩溶带耦合发育,上覆土壤中大孔隙与下伏表层岩溶带中裂隙、管道存在密切的水力联系,然而土壤大孔隙影响土壤—表层岩溶带系统中水土漏失的过程机理尚不清楚。通过人工模拟降雨试验,采用试验微区模拟不同土壤大孔隙形态(出露型、浅埋型、深埋型),并以全土微区为对照,探讨了土壤大孔隙对喀斯特地区水土漏失过程的影响。结果表明:与全土微区相比,土壤大孔隙的存在明显加速了水分的垂直渗漏,其对水分渗漏量的影响表现在峰值不同(出露型 > 浅埋型 > 深埋型 > 全土 ...
周春衡 +4 more
doaj
ABSTRACT Porous NiTi alloys are widely used in biomedical and engineering fields. Using the PBF‐LB technique, the TPMS and Voronoi porous parts with a porosity of ∼67% and a minimum feature size of 0.15 ± 0.02 mm were fabricated. Although the bulk sample fabricated with the same parameters is defect‐free, μ‐CT reconstruction on the porous sample ...
Wen‐Hao Zeng +7 more
wiley +1 more source
ABSTRACT The development of high‐performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs.
Changlong Du +9 more
wiley +1 more source
土壤大孔隙是土壤水分、空气、化学物质及污染物优先运移的主要通道,对其形成机制的研究至关重要。以往对大孔隙的量化局限于传统方法,大孔隙三维形态特征的量化分析及其影响因素是目前大孔隙的研究重点。利用CT扫描及图像处理分析技术量化大孔隙三维形态特征参数,同时测定土壤基本理化性质及根长密度,分析土壤大孔隙三维特征对土壤理化性质及根系的响应。结果表明:土壤密度及土壤砂粒含量与大孔隙特征参数不存在相关关系)土壤有机质含量、土壤根长密度与大孔隙体积密度、大孔隙表面积密度、大孔隙数量密度呈现显著正相关关系 ...
孟晨, 牛健植, 骆紫藤, 尹正聪
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract Grazing by large herbivores is a critical factor shaping grassland biodiversity and ecosystem functioning worldwide, yet its consequences for soil communities remain poorly understood.
Quanhui Ma +12 more
wiley +1 more source
根系的存在对土壤大孔隙的产生及渗透特性有着重要影响,为研究浅表层土体中根系生物量与土壤大孔隙特征之间的数值关系,在缙云山针阔混交林中选取杉木单株植物根际土体为研究对象,进行染色示踪试验及根系生物量测量,取样后在室内采用自制定水头装置进行水分穿透试验和渗透试验。结果表明:(1)不同土壤剖面和不同土层深度的土壤染色面积不同,距离树木主干位置越远的剖面染色面积越大,而距离主干位置越近的剖面染色面积越小,且随着土层深度的增加整体上每个剖面上染色面积比均下降;(2 ...
祁子寒 +5 more
doaj
Targeting the conglomerate reservoir of the Lower Karamay Formation in the Middle District No.6 of Karamay Oilfield, based on the research of conglomerate reservoir characteristics and flow mechanism, laboratory experiments were conducted to study the ...
Xu Changfu +3 more
doaj +1 more source
为探究大气氮沉降增加导致的土壤团聚体结构变化规律及其对土壤水分入渗性能的影响,在贡嘎山针叶成熟林和中龄林内分别设计2种氮肥形态[(NH4)2SO4、KNO3]和4个浓度水平(0,10,20,40 kg/(hm2·a)N)的添加试验,研究不同形态大气氮沉降对亚高山森林土壤团聚体结构和土壤水分入渗特征的影响。结果表明:(1)随施氮量增加,中龄林土壤大团聚体含量逐渐增加,土壤持水量、孔隙度和水分稳定入渗率逐渐增大;成熟林土壤大团聚体含量、土壤持水量、孔隙度和水分稳定入渗率均表现出先增加后降低的趋势;(2 ...
郭海云, 王根绪, 孙守琴
doaj

