Results 31 to 40 of about 1,470 (142)
Effects of Native Forest Conversion on Soil Labile Organic Carbon and Enzyme Activity in Northwestern Hunan Province [PDF]
, 2023 [Objective] The response of soil labile organic carbon components and enzyme activities to natural forest conversion was analyzed in order to provide a scientific basis for predicting regional soil health evolution and environmental change.
Li Xue +5 more
core +1 more source
Effects of Biochar Application on Nitrogen and Phosphorus Availability in Soils: aReview [PDF]
, 2016 利用生物炭在贫瘠的土壤上培育出肥沃的"黑土"正成为土壤学家研究的热点.氮、磷等大量养分是衡量土壤肥力高低的重要指标,生物炭对其有效性影响表现出极大的复杂性.不同研究得出的结论不尽相同,关键是缺乏对其机制的深入研究.由于氮和磷的不合理利用还可能造成非点源污染而带来环境风险,再加之生物炭施用的不可逆性,必须确保生物炭在任何情况下都不会对土壤和环境带来不利的影响.为此,本文综述了生物炭添加对氮肥和磷肥在土壤-植物系统迁移转化过程中的作用,重点讨论了不同生物炭处理方式对土壤磷素吸附解吸和形态转化的影响 ...
张友 +4 more
core +1 more source
, 2015 建立HPLC 法测定菊芋叶中绿原酸含量的方法,对菊芋植株中不同部位绿原酸的分布规律,以及不同品系、盐度、采摘时间等因素对菊芋叶中绿原酸含量的影响情况进行研究。方法:色谱柱为Hypersil BDS C-18(4.6×250 mm,5 μm),流速为1 mL min-1 ,检测波长为327 nm,进样量为10 μL,柱温为30℃,流动相为0.1%三氟乙酸水(A)-乙腈(B)。结果:菊芋叶中绿原酸的含量(3.40%)显著高于其他部位绿原酸的含量;10 ...
夏传海 +1 more
core
Landslide susceptibility assessment in Shenzhen based on multi-scale convolutional neural networks model [PDF]
Convolutional neural network (CNN) models are widely used in landslide susceptibility assessment due to their powerful feature extraction capabilities, and traditional CNN is no longer able to meet the requirements. Therefore, this paper proposes a multi-
Binghai GAO +7 more
core +1 more source
Shuitu Baochi Xuebao, 2006 采用田间采样及室内培养方法，对内蒙古武川县耕地、退耕还灌地和放牧草原3种类型土地土壤微生物各类群的数量分布和层化比率进行了研究。结果表明：在土壤耕作层（0～30cm）土壤微生物数量呈逐层下降趋势，3种类型土地的土壤微生物总数相差不大，3种类型土地土壤微生物层化比率存在明显差异。同时提出了土壤微生物层化比率的概念，并认为土壤微生物层化比率可能是一个比较好的指示动态土壤质量（土壤演替方向）的指标，当一个区域土壤微生物层化比率大于2时，土地一般不会发生退化现象。在研究的3块实验区域中，耕地存在较高的退化风险 ...
李涛 +4 more
doaj +2 more sources
Greenhouse gas emissions from croplands of China [PDF]
, 2003 China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate.
Bohan, Liao +13 more
core +1 more source
Landslide susceptibility modeling and interpretability based on CatBoost-SHAP model [PDF]
This study is dedicated to delving deeply into the uncertainty and interpretability of ensemble learning models in landslide susceptibility modeling. Focusing on the eastern coastal mountainous region of Zhejiang Province as the study area, this research
Fan WU +4 more
core +1 more source
Shuitu Baochi Xuebao, 2018 为了研究荒漠草原不同土壤类型对降水的响应过程，在宁夏盐池县皖记沟村选取分布较广的灰钙土、风沙土和基岩风化残积土为研究对象，采用双环法测定其入渗过程，分析并比较三者的入渗特征，利用模型拟合土壤入渗过程。结果表明：研究区内3种类型土壤入渗过程大致可分为3个阶段，0~5 min入渗速率急剧下降阶段，5~10 min入渗速率逐渐变缓并趋于稳定及30 min后入渗速率达到相对稳定的状态。通过对不同土壤初始入渗速率、稳定入渗速率及60 min累积入渗量对比分析，发现不同土壤类型的入渗特征存在差异 ...
陈娟 +5 more
doaj
Shuitu Baochi Xuebao, 2003 以长江上游典型区彭州市为例,在该区SOTER(1∶50 000)数据库的支持下,选取地貌类型 、坡度、植被覆盖率、土地利用、土壤类型等作为评价因子,运用专家权重模型,将研究区 分为无险型、轻险型、危险型、强险型和极险型5种类型,输出了土壤侵蚀危险度评价图, 并指出了各种类型的防治侵蚀的措施.
周红艺 +3 more
doaj +2 more sources
The Spatio-temporal Evolution of NDVI in the Three Gorges Reservoir Area Driven by the Synergistic Effect of two Factors over the Past 21 Years [PDF]
[Objective] To clarify the spatio-temporal characteristics of vegetation evolution in the Three Gorges Reservoir Area, and to quantitatively analyze the relationships between vegetation and key determinants, including climate, terrain, and human ...
LI Cheng +5 more
core +1 more source