Results 51 to 60 of about 1,739 (198)

不同品种、盐度及月份菊芋叶中绿原酸的含量测定 [PDF]

open access: yes, 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  

Effects of Native Forest Conversion on Soil Labile Organic Carbon and Enzyme Activity in Northwestern Hunan Province [PDF]

open access: yes, 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

Indian Pangolin in Lamjung Requires Urgent Attention 尼泊尔拉姆琼县地区的印度穿山甲急需关注

open access: yesWildlife Letters, Volume 2, Issue 4, Page 204-213, December 2024.
This study documented the first evidence of the Indian pangolin in Lamjung district, Nepal, finding three burrows and rescue evidence in Simalchaur Naringhat Community Forest. The burrows identified at an elevation of 530 m and characterized by moderate crown and ground cover (26%–50%), a 25° slope, and predominantly red soil, are indicative of a ...
Asmit Neupane   +4 more
wiley   +1 more source

Changing plant phosphorus acquisition strategies in relation to altered soil phosphorus fractions after wetland drainage

open access: yesFunctional Ecology, Volume 38, Issue 11, Page 2433-2446, November 2024.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Plant phosphorus (P) acquisition strategy is considered to be an intrinsic driver behind plant succession. However, variations in plant P acquisition strategies in connection to soil P fraction changes after wetland drainage remain unclear.
Zhenhui Jiang   +6 more
wiley   +1 more source

Landslide susceptibility assessment in Shenzhen based on multi-scale convolutional neural networks model [PDF]

open access: yes
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

重庆岩溶地区不同土壤类型的土地利用多样性分析

open access: yesShuitu Baochi Xuebao, 2006
以重庆岩溶地区为例,探讨岩溶地区土壤类型的多样性与不同土壤类型上土地利用方式的多样性。结果表明重庆市岩溶区黄壤、石灰土和黄棕壤是本区主要土壤类型,土壤景观的多样化和空间异质化程度不高,但各类景观分布比例不均匀,土壤景观嵌块体呈现出复杂的几何形状。除了山地草甸土以林地和草地、棕壤以林地为主要景观外,另外的9种土壤类型上都是以耕地和林地为主要的景观,农、林用地在景观空间格局的结构和功能中起主导作用。由于各类土壤性质和分布特点的不同,耕地和林地在各类土壤上的分配比例存在着明显的差异 ...
王子芳   +6 more
doaj  

植被类型对黄土丘陵区土壤碳氮磷化学计量特征的季节变异

open access: yesShuitu Baochi Xuebao, 2021
为探讨植被类型及生长季阶段对土壤碳氮磷生态化学计量特征的影响,揭示黄土丘陵区陆地生态系统养分限制及循环规律。以黄土丘陵区典型荒草地(Grassland)、苜蓿(Medicago Sativa)地、沙棘(Hippophae rhamnoides)灌木地、文冠果(Xanthoceras sorbifolium)林地、云杉(Picea asperata)林地为研究对象,分析其0—60 cm土壤有机碳(SOC)、全氮(TN)、全磷(TP)含量及化学计量比特征在植被类型间及生长季阶段内的差异。结果表明:(1 ...
刘帅楠   +5 more
doaj  

Landslide susceptibility modeling and interpretability based on CatBoost-SHAP model [PDF]

open access: yes
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

北方农牧交错带(武川县)土壤微生物数量分布及层化比率研究

open access: yesShuitu 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

荒漠草原不同土壤类型水分入渗特征

open access: yesShuitu 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  

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