Results 1 to 10 of about 1,047 (189)

Effects of nitrogen addition and mowing on nitrogen- and water-use efficiency of Artemisia frigida in a grassland restored from an abandoned cropland [PDF]

open access: yes, 2021
Aims Competition among plants in a community usually depends on their nitrogen (N)-use efficiency (NUE) and water-use efficiency (WUE) in arid and semi-arid regions.
Diao, Huajie   +3 more
core   +1 more source

一种食用油锁养保鲜生产工艺 [PDF]

open access: yes, 2023
为了解决食用油在储存过程中因发生各种变化而造成的品质下降问题,介绍了一种食用油的锁养保鲜生产工艺,包括全工段恒温灌装、充氮灌装和抗紫外瓶包装。实践证明,全工段恒温灌装有效避免了灌装油温过高产生负压造成的瓶内缩吸瘪,减少了标签不平整情况的发生;充氮灌装使食用油包装瓶内顶空残氧量低于6%,产品残氧量指标稳定;以色母为抗紫外助剂,制成的食品级食用油包装瓶可防止紫外线对食用油品质的影响。采用此生产工艺,可以有效提高食用油的品质并延长储存期。 In order to solve the problem of ...
王志军,赵仕峰,夏金涛WANG Zhijun, ZHAO Shifeng, XIA Jintao
core   +2 more sources

Interspecific interactions affect N and P uptake rather than N:P ratios of plant species: evidence from intercropping [PDF]

open access: yes, 2021
Quantifying stoichiometry of crop N and P acquisition (i.e. removal from farmland) under different agronomic practices is essential for understanding nutrient budgets and optimizing N and P fertilizer application in agroecosystems.
Fornara, Dario   +7 more
core   +1 more source

Responses of Stem Sap Flow and Diameter of Ailanthus Altissima to Soil Moisture [PDF]

open access: yes, 2022
[Objective] In order to understand the water use strategy of Ailanthus altissima and to formulate efficient water management measures for A. altissima, we investigated the characteristics of sap flow and radial stem variation of A.
Liu Yunjie   +3 more
core   +1 more source

Soil Salinization Characteristics of Different Land Use Types in a Typical Oasis Irrigation Area of Lower Tarim River [PDF]

open access: yes, 2023
[Objective] The soil salinization characteristics under different land use types in extremely arid regions were analyzed in order to provide support for the sustainable efficient utilization of regional land resources.
Baiyun Gang   +6 more
core   +1 more source

林分类型和氮添加对亚热带森林土壤氧化亚氮排放的影响

open access: yesShuitu Baochi Xuebao, 2023
为揭示亚热带森林土壤N2O排放对林分类型和氮添加的响应特征,选取位于福建省三明市的中亚热带米槠次生林、杉木人工林和马尾松人工林土壤为研究对象,分别设置无氮添加(N0 mg/kg)、低氮添加(N10 mg/kg)、中氮添加(N25 mg/kg)和高氮添加(N50 mg/kg)4个氮添加水平,进行微宇宙培养试验,测定土壤N2O排放。结果表明:与无氮添加处理相比,氮添加整体上降低3种林分土壤pH,增加土壤NH4+-N和NO3--N含量。无氮添加处理中杉木人工林和马尾松人工林土壤N2O累积排放量分别为9 ...
邓米林   +5 more
doaj  

氮添加对华北落叶松叶片化学计量与养分重吸收效率的影响

open access: yesShuitu Baochi Xuebao, 2021
为了解华北落叶松林叶片化学计量特征和养分重吸收效率与N素供应的关系,以24年生华北落叶松人工林为研究对象,设置3个水平(0,8,15 g/(m2·a))连续6年的野外氮添加控制试验,测定氮添加后华北落叶松成熟叶片、凋落叶片和林分土壤养分含量的变化。结果表明:成熟叶片C含量在年际间差异显著 ...
李素新, 张芸香, 郭晋平
doaj  

短期氮添加对荒漠草原土壤微生物特征的影响

open access: yesShuitu Baochi Xuebao, 2022
为探究荒漠草原土壤微生物特征对短期氮添加的响应,以宁夏荒漠草原为对象,参照国内外同类研究和当地的氮沉降量,设置N0、N1、N2、N3、N4的5个处理,其纯氮添加量分别为0,2.5,5,10,15 g/(m2·a),以尿素为氮源进行为期2年的氮添加试验,对不同氮添加处理下荒漠草原浅层土壤微生物特征进行了研究。结果表明:(1)随氮添加量的增加,荒漠草原0—20 cm土层土壤铵态氮含量呈升高的变化趋势,硝态氮含量呈先升高后下降的变化趋势。在0—10 cm土层,N1、N2、N3 ...
宋珂辰   +5 more
doaj  

长期氮沉降和地上凋落物处理对半干旱区沙质草地表层土壤碳氮组分的影响

open access: yesShuitu Baochi Xuebao, 2023
为揭示半干旱区沙质草地生态系统中表层土壤C、N组分对长期氮添加和地上凋落物处理的响应特征,以科尔沁沙地西南部国家野外科学观测研究站建立的长期(9年)氮添加和凋落物处理样地为平台,测定并分析该样地表层土壤环境因子、铵态氮、硝态氮、总有机碳、不同碳氮组分。结果表明:(1)持续9年的氮添加和地上凋落物处理对表层土壤环境因子和不同碳氮组分无交互作用;(2)氮添加处理显著降低土壤pH ...
詹瑾   +8 more
doaj  

超高效液相色谱法测定聚乙烯类食品接触材料中8种添加剂

open access: yesSe pu = Chinese journal of chromatography, 2021
食品接触材料中添加剂残留量的测定为食品接触材料从源头进行安全监管具有重要意义。然而目前的大多数研究只针对食品接触材料中有害物迁移量的测定,对于食品接触材料中有害物含量的测定方法仅局限于残留单体、低聚体、重金属,以及邻苯二甲酸酯类、双酚类化合物等环境污染物,对食品接触材料中添加剂残留量的测定较少。该研究系统地优化了样品前处理过程及仪器分析中影响8种添加剂分析准确度与响应灵敏度的各主要因素,建立了超高效液相色谱同时测定聚乙烯材料中8种添加剂的定量分析方法。聚乙烯样品冷冻研磨后,取2.0 ...
Yun-Biao Ling   +5 more
semanticscholar   +1 more source

Home - About - Disclaimer - Privacy