Results 21 to 30 of about 1,489,744 (171)

长白山森林土壤有机碳库大小及周转研究

open access: yesShuitu Baochi Xuebao, 2006
主要分析不同森林植被下有机碳的分解动态和土壤碳库各组分大小、周转时间。结果表明:土壤样品培养90天,CO2累计释放量表层大致为1723~5065mg/kg、下层大致为178~642mg/kg。分解速率总的趋势是前期快,后期慢,表层明显大于下层。大小顺序为:冷杉林〉针阔混交林和阔叶林〉针叶林。在不同植被下的表层和下层土壤中,活性碳占总有机碳的0.54%~1.67%,0.45%~5.48%.平均驻留时间为11~56天、60~88天;缓效性碳占总有机碳的23.0%~63.3%,33.2%~72.2 ...
邵月红   +3 more
doaj   +2 more sources

紫色土丘陵区坡面土壤有机碳含量及储量分布特征

open access: yesShuitu Baochi Xuebao, 2017
为探明坡耕地土壤有机碳空间分布特征,对紫色土丘陵区坡耕地不同部位土壤有机碳及活性有机碳顺坡和深度分布进行分析。结果表明,坡耕地上坡土层深度仅为22.3 cm,中坡和下坡土层深度约为上坡的2.01倍和3.30倍;与上坡比较,中坡和下坡土壤容重下降了0.2和0.04,土壤孔隙度增加了19.82%与3.83%。沿坡从上向下土壤有机碳及活性有机碳储量显著增加,下坡土壤有机碳及活性有机碳储量比上坡和中坡分别增加了674.74%,104.09%和958.51%,267.75 ...
樊红柱, 张泽洪, 郭, 蒋
doaj  

长期施肥对稻麦轮作紫色土有机碳组分及酶活性的影响

open access: yesShuitu Baochi Xuebao, 2022
为了探明西南地区长期不同施肥处理对稻麦轮作紫色土有机碳组分和碳循环相关水解酶活性的影响,依托重庆北碚29年稻麦轮作紫色土长期定位试验,选取不施肥(CK)、单施氮磷钾肥(NPK)、有机无机配施(NPKM)、秸秆还田配施含氯化肥[(NPK)ClS]和秸秆还田配施无机肥(NPKS)5个处理,测定土壤各组分有机碳含量及与土壤碳循环相关的水解酶活性并分析两者间的相关性。结果表明:长期施肥(NPK、NPKM和NPKS)显著提高土壤总有机碳和不同组分有机碳含量,各施肥处理土壤总有机碳含量较CK提升11.6%~40.2%
徐文静   +7 more
doaj  

Synergistic Dual‐Defect Engineering in Amorphous‐Nanocrystalline Heterostructures for Accelerated Oxygen Evolution

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Defect engineering has been widely demonstrated as an effective strategy for enhancing the activity of OER metal catalysts, among which the introduction of twin boundaries (TBs) has proven particularly efficient. However, single‐type defects offer limited performance enhancement.
Wentao Cai   +11 more
wiley   +1 more source

不同土地利用方式对土壤活性有机质的影响

open access: yesShuitu Baochi Xuebao, 2011
不同土地利用方式会影响土壤碳氮通量的活性有机质储量,以撂荒地、沙棘灌木林、华北落叶松人工林和华北落叶松-白桦-山杨混交林为研究对象,测定土壤容重、持水量、粒径组成、分型维数和pH值,并应用H2SO4两步酸水解法测定了土壤活性和顽固性碳氮的季节变化.结果表明:5年弃耕撂荒地土壤理化特征及不同活性有机质含量最差,而沙棘灌木林和乔木林在土壤物理、化学特征和有机质含量方面均有所提高,尤以混交林土壤质量最佳.有机碳和不同活性碳是撂荒地的2~3倍左右,总氮及不同活性氮提高幅度较小,在1.1~1.5之间 ...
李君剑   +4 more
doaj  

Leaf C:P ratio as a universal indicator of photosynthesis in subtropical woody species: Stoichiometric thresholds and metabolic trade‐offs

open access: yesFunctional Ecology, Volume 40, Issue 7, Page 2332-2344, July 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometric ratios of carbon (C), nitrogen (N) and phosphorus (P) serve as important indicators for assessing nutrient balance in forest ecosystems, but their relationships with photosynthetic dynamics require deeper characterization.
Minghao Chen   +9 more
wiley   +1 more source

不同森林植被下土壤有机碳的分解特征及碳库研究

open access: yesShuitu Baochi Xuebao, 2005
分析了不同森林植被和同一植被不同林龄的人工杉木林下土壤有机碳的分解特征及土壤有机碳中的活性碳库、缓效性碳库和惰效性碳库的大小和周转时间。结果表明:不同森林植被下土壤有机碳的分解速率不同,总的趋势都是:培养前期分解速度快,后期分解速度慢,土壤剖面A层>剖面B层。在剖面A层中:不同森林植被下分解速率的大小顺序为常绿阔叶林>人工杉木林,不同林龄的人工杉木林为成熟林>中龄林>幼龄林;在剖面B层中:分解速率差异不大。不同森林植被下不同土壤剖面上的土壤活性碳库、缓效性碳库和惰效性碳库的库容和分解速率不同 ...
邵月红 潘剑君 孙波
doaj   +2 more sources

Land use overrides climatic controls on soil organic nitrogen transformations: Contrasting responsiveness between forest and cropland ecosystems

open access: yesFunctional Ecology, Volume 40, Issue 7, Page 2128-2142, July 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil organic nitrogen (SON) transformation is critical for global nutrient cycling and ecosystem productivity, yet how its responsiveness to climate change differs across diverse land use types remains poorly resolved.
Xinyi Yang   +10 more
wiley   +1 more source

杜氏盐藻碳酸酐酶N/C结构域耐盐性的研究

open access: yes四川大学学报. 自然科学版, 2011
为研究杜氏盐藻碳酸酐酶的两个结构域的耐盐性,将杜氏盐藻碳酸酐酶的两个串联结构域分别表达与纯化,利用酶学方法和光谱学方法分别研究这两个结构域各自的活性及其对盐的耐受性.研究发现,N端结构域不具有催化活性,仅有C端结构域具有活性,而且其活性随着盐浓度的增加而增加,这同杜氏盐藻碳酸酐酶在广泛的盐浓度内的活性变化趋势一致.光谱学方法发现,随着盐浓度的增加,C端结构域的二级结构和三级结构并不发生显著变化,活性中心结构逐渐松弛,从而增加了C端结构域活性中心的活力,提高了盐藻碳酸酐酶的活性.
杨爽, 蒋彦
doaj  

Nitrogen–Doped Carbon Nanotube–Supported Ni3Se4–CeO2 Heterojunctions With Multi–Orbital Hybridization for Efficient Hydrogen Evolution Reaction

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Engineering of the catalyst interface and modulation of transition–metal d–band play critical roles in the electrocatalytic hydrogen evolution reaction (HER). Herein, a synthetic strategy is developed to fabricate nitrogen‐doped carbon nanotubes (N–CNTs)–supported Ni3Se4–CeO2 heterojunction catalysts through a facile chemical vapor deposition (
Zhiqiang Sun   +10 more
wiley   +1 more source

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