Results 21 to 30 of about 4,287 (179)

Effects of Configuration Ratios for Contour Planting and Replanted Sugarcane on Gully Erosion-Induced Nitrogen and Phosphorus Losses on Slopes [PDF]

open access: yes, 2023
[Objective] The suitable configuration ratios for contour planting and replanted sugarcane on slopes were determined in order to provide technical support for reducing slope ditch erosion and nutrient loss, improving cultivated land quality and rational ...
Chen Tingting   +8 more
core   +1 more source

Effects of Different Ratios of Mineral-solubilizing Microbes and Water-retaining Agents on Soil Nutrients and Enzyme Activities [PDF]

open access: yes, 2022
[Objective] The effects of mixed additions of a water-retaining agent and bacterial agents on soil characteristics were determined in order to provide a theoretical basis for promoting mine vegetation restoration.
Chen Meiling   +6 more
core   +1 more source

灌溉方法对保护地土壤有机氮组分及剖面分布的影响

open access: yesShuitu Baochi Xuebao, 2007
用Bremner有机氮分组法测定了连续7年采用不同灌溉方法灌溉的保护地土壤各剖面层次有机氮组分含量。结果表明,土壤全氮及有机氮各组分含量均随土层深度的增加而降低,但有机氮各组分占全氮的比例随土层深度增加的变化却无明显规律。用3种灌溉方法灌溉,不同土层间土壤有机氮各组分含量的差异主要存在于0~50 cm土层,50 cm以下差异很小;相同土层,土壤有机态氮含量均以酸解氮为主,且酸解氮中各组分绝对含量和相对含量的大小排列顺序均为,未知态氮>氨态氮>氨基酸态氮>氨基糖态氮。在0~80 cm土层,
姬景红   +4 more
doaj   +2 more sources

川西低山丘陵区植茶土壤团聚体矿质氮分布特征

open access: yesShuitu Baochi Xuebao, 2022
研究植茶对土壤团聚体全氮和矿质氮的影响可为茶园土壤合理施用氮肥提供理论依据。通过野外调查和室内分析, 研究不同茶树品种(福鼎大白、川茶3号、川农黄芽早和川沐217)对土壤团聚体中全氮和矿质氮含量的影响。结果表明: (1)各植茶品种土壤团聚体含量随粒径减小呈先减小后增大的变化趋势, >2 mm粒径团聚体含量显著高于其他粒径团聚体, 其含量约占总量的38.32%~66.26%。(2)各植茶品种土壤全氮含量均随团聚体粒径的减小呈先减小后平稳的趋势, 而铵态氮和硝态氮的变化趋势则相反。(3 ...
于子涵   +3 more
doaj  

塔里木沙漠公路防护林土壤微生物生物量与土壤环境因子的关系 [PDF]

open access: yes, 2009
为探讨极端干旱区风沙土土壤微生物与土壤环境因子的作用规律,采用相关分析法研究了塔里木沙漠公路防护林地土壤微生物生物量与理化因子和酶活性的关系.结果表明:土壤容重和粒径减小(R0.85)时,防护林地中土壤微生物数量和生物量有增大趋势,由容重与微生物量的相关性主导;土壤养分含量与土壤微生物数量和生物量呈正相关,主要由速效养分和放线菌、微生物生物量C、P的相关性所致;土壤酶活性与土壤微生物数量和生物量的相关性差异较大,R在0.51~0.91,主要取决于蔗糖酶、磷酸酶与放线菌、微生物量C的相关 ...
周宏伟   +7 more
core  

Effects of nitrogen application time on fruit setting rate and lignin accumulation during sepal development of Kuerlexiangli pear [PDF]

open access: yes
[Objective] Sepal shedding of Kuerlexiangli pear (Pyrus brestschneideri Rehd.) is a key factor in determining fruit quality and economic value. Nitrogen is an essential element for the growth of fruit trees, and has a profound influence on the growth and
BAO Jianping   +4 more
core   +1 more source

Electronic Modulation of CoNi Nanoparticles by N‐Doped Carbon for Efficient Lignin Hydrogenolysis to Aromatic Monomers

open access: yesRare Metals, EarlyView.
ABSTRACT Cost‐effective and efficient non‐noble‐metal catalysts for selective lignin hydrogenolysis remain elusive, representing a significant challenge in biorefinery. Here, we prepared a nitrogen‐doped carbon supported CoNi bimetallic catalyst, which was successfully derived from zeolitic imidazolate framework (ZIF) via high‐temperature pyrolysis ...
Xingwei Luo   +3 more
wiley   +1 more source

由光敏性全氢聚硅氮烷制备透明高硬Si—O微/纳米结构压印模板

open access: yes, 2012
面向可用作压印模板的透明高硬微/纳米结构的低成本制备,无机高分子全氢聚硅氮烷用甲基丙烯酸(2-异氰酸基乙酯)进行光敏改性,经FTIR,1H-NMR,13C-NMR等手段表征,推断获得的是甲基丙烯酸酯化的全氢聚硅氮烷(MPHPS),并以此为原料,用一种含氟聚合物(FP)模板,施加0.1~0.4 MPa的压力,紫外压印制备MPHPS的微结构,发现增加压力,压印复制效果提高,0.23 MPa可以完全复制FP模板的微结构.此外,在0.4 MPa的压力下也制备了分辨率为90 nm,70 nm的纳米级结构 ...
方庆玲   +3 more
semanticscholar   +1 more source

Different forms of nitrogen contents and their vertical variations of transformation modes of the sediments of Lake Yuehu, Wuhan [PDF]

open access: yes, 2008
Vertical distributions of nitrogen contents, net nitrification rates, net N-mineralization rates and nitrate reductase activities in sediments of Lake Yuehu in June, 2005, were described on basis of four samples from the lake.
Chen Guoyuan   +5 more
core  

Soil Particle Settlement Sorting and Distribution Characteristics of Carbon, Nitrogen and Salt During Gradual Thawing [PDF]

open access: yes, 2023
[Objective] The classification of sediment particles and the accompanying distribution characteristics of carbon, nitrogen and salt in the process of soil thawing layer by layer under snowmelt runoff scenario were analyzed in order to identify the ...
Hu Yaxian   +5 more
core   +1 more source

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