Results 31 to 40 of about 501 (114)

Advocacy strategies in state preemption: The case of energy fuel bans

open access: yesPolicy Studies Journal, Volume 52, Issue 2, Page 257-282, May 2024.
Abstract Interest group literature suggests reformer advocacy groups, seeking policy change and innovation, are more likely to secure policy victory in local government. Entrenched advocacy groups, favoring current policies, are better suited to win policy battles at the state level.
Cory L. Struthers, Cary Ritzler
wiley   +1 more source

贺兰山不同海拔植被下土壤团聚体分布及其稳定性研究

open access: yesShuitu Baochi Xuebao, 2021
以贺兰山不同海拔植被下0—20,20—40 cm土层土壤为研究对象,分析不同粒径团聚体含量及团聚体稳定性随海拔升高的变化特征,探讨其与土壤理化性质之间的相关关系。结果表明:0—20 cm土层,0.25~0.053 mm团聚体为主要团聚体类型,随海拔增加,水稳性大团聚体(>0.25 mm)含量增加,高海拔>低海拔,较高含量的大团聚体和土壤养分是团聚体稳定的关键要素。
吴梦瑶   +6 more
doaj  

Distribution Pattern of Cadmium in the Profile of Shallow Fissure Soil and Its Influencing Factors in Karst Areas with High Geological Background [PDF]

open access: yes
[Objective] To study the vertical distribution pattern of cadmium (Cd) in shallow karst fissure soil, analyze the impacts of various factors on the distribution of Cd in fissures, and provide a scientific basis for future research on the distribution ...
CAI Huayin   +6 more
core   +1 more source

黄土丘陵区刺槐林土壤团聚体稳定性和土壤可蚀性动态变化

open access: yesShuitu Baochi Xuebao, 2023
退耕还林工程是黄土高原控制水土流失的主要措施之一,探讨退耕还林对土壤团聚体稳定性与土壤可蚀性的影响,可为黄土高原地区生态恢复和水土保持效益评价提供科学依据。以农田为对照,选取不同退耕年限(5,10,15,20,25,30年)刺槐林为研究对象,研究退耕还林后0—30 cm土层土壤团聚体稳定性和土壤可蚀性动态变化,并探讨土壤可蚀性与土壤团聚体稳定性之间的关系。结果表明:(1)>0.25 mm水稳性团聚体含量、平均重量直径、几何平均直径随着退耕年限增加呈递增趋势,三者相比退耕前(农田)分别增加32%~79 ...
范家伟   +3 more
doaj  

应用Le Bissonnais法测定富铁土中团聚体的稳定性及其意义

open access: yesShuitu Baochi Xuebao, 2004
土壤团聚体的数量和稳定性是衡量土壤抗蚀性和土壤质量的重要指标,应用LeBissonnais法对富铁土团聚体的稳定性和物理学机制进行了研究。结果表明,LeBissonnais法测定的团聚体平均重量直径(MWD)与常规湿筛法测定的>0.25mm团聚体含量、MWD和>2mm团聚体破坏率(PAD)呈极显著正相关。富铁土中5~2,2~1,1~0.5mm团聚体经快速湿润(FW)、慢速湿润(SW)和预湿后扰动(WS)处理后,稳定性团聚体的粒级分布随处理方式和初始团聚体大小的不同而不同;经FW处理后,大多数团聚体崩解 ...
卢升高 竹蕾 郑晓萍
doaj   +2 more sources

Optimization of Extraction Method for Easily Extractable Glomalin-Related Soil Protein from Calcareous Soil [PDF]

open access: yes
Glomalin-related soil protein (GRSP) secreted by arbuscular mycorrhizal fungi is widely distributed worldwide, has stable properties and is not easily decomposed, which is an important component of soil organic matter.
Chun TU   +5 more
core   +1 more source

大桥水库消落带不同水位高程柳树林地土壤团聚体组成与分形特征

open access: yesShuitu Baochi Xuebao, 2021
为研究植被恢复对水库消落带土壤团聚体组成及稳定性的影响,利用干筛和湿筛法,测定了大桥水库消落带不同水位高程下柳树林地土壤团聚体组成分布,并基于分形理论分析了土壤团聚体分形特征。结果表明:(1)消落带柳树林地土壤>0.25 mm非水稳定性团聚体和水稳性团聚体分别为73.13%~93.69%和47.62%~82.06%,较对照无植被样地土壤均有所增加,但两者差异不明显;消落带土壤大团聚体含量随水位高程升高而降低,随土层深度增加而减少,但在不同水位高程和不同土层间均无显著性差异(p>0.05)。(2 ...
宋娇   +4 more
doaj  

The Impact of Mixed Application of Modified Straw Biochar and Organic Fertilizer on Soil Water Retention and Fertility Maintenance in the Loess Hilly Dry Area [PDF]

open access: yes
[Objective] This study aimed to investigate the effects of different modified corn straw biochars on the water retention and fertilizer conservation capacity of arid loess soil and their effects on crop growth.
CHANG Fangling   +5 more
core   +1 more source

子午岭林区植被自然恢复下土壤剖面团聚体特征研究

open access: yesShuitu Baochi Xuebao, 2011
研究了子午岭林区七种植被类型土壤>0.25 mm水稳性团聚体含量、团聚体破坏率和水稳性团聚体分形维数随植被恢复的变化规律以及这3个指标随土壤有机碳含量增加的变化规律。结果表明:植被恢复对>0.25 mm水稳性团聚体含量、团聚体破坏率和水稳性团聚体分形维数的影响可以达到70 cm土层;除白羊草群落外,0-70 cm土层上>0.25 mm水稳性团聚体含量随植被恢复逐渐提高,团聚体破坏率和水稳性团聚体分形维数随植被恢复逐渐减小,土壤结构随植被恢复逐渐改善。>0.25 mm水稳性团聚体含量 ...
马帅   +4 more
doaj  

Sorption /desorption behaviors of pyrene on mangrove sediment aggregates with different sizes [PDF]

open access: yes, 2014
采用海藻酸钙凝胶包覆的方法,研究了芘在九龙江河口红树林区不同粒径沉积物团聚体上的吸附/解吸行为.结果表明,海藻酸钙凝胶包覆可有效减少沉积物团聚体粒径的改变,其等温吸附、吸附/解吸速率情况与未包覆沉积物团聚体存在明显差异.包覆后等温吸附曲线中吸附容量kf值取决于总有机碳(TOC)的含量,非线性吸附常数n不仅与其硬碳和软碳的比值有关,还与团聚体复杂的孔隙结构存在着一定的关系.包覆后沉积物团聚体的快吸附速率常数值与沉积物团聚体的比表面积值正相关(krAP=0.041S-0.0146,r2=0.9923 ...
刘贝贝, 张勇, 朱亚先, 李锐龙
core  

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