Results 31 to 40 of about 12,677 (160)

解冻期覆沙黄土坡面能量参数与径流产沙关系

open access: yesShuitu Baochi Xuebao, 2021
为探究春季解冻期覆沙黄土坡面能量参数动态响应时空演化过程,在相同放水流量(1 L/min)条件下,采用2个土壤处理(未冻坡面,冻结坡面)和4个覆沙厚度(0,1,2,3 cm)进行室内模拟冷冻和放水冲刷试验,系统分析了径流流速(V)、径流功率(W)、单位径流功率(P)和径流动能(E)在不同土壤处理和不同覆沙厚度条件下的时空演化过程。结果表明:(1)不同处理下的径流流速随产流时间的延长总体呈下降趋势,随着距坡顶距离的增大总体呈增大趋势。未冻坡面和冻结坡面径流流速的均值在0.23~0.35,0.18~0.35
王伟   +6 more
doaj  

The Effect of N2O Emission Mitigation by Growing Soybeans Instead of Other Crops [PDF]

open access: yes, 2016
农业是重要的温室气体排放源之一,而在农业生产过程中施用氮肥是引起农业温室气体排放的主要原因。因此,如何合理有效的施用氮肥对减少农业温室气体排放、减缓全球气候变化至关重要。鉴于此,对通过合理施用氮肥从而减少温室气体排放的减排措施进行成本效益分析,将有助于我们找到具有经济效益的农业温室气体减排方法。目前,相关减排措施研究主要集中在农田测土配方施肥、改良施肥(缓释肥和长效肥)上。得益于与豆类作物共生的根瘤菌具有的固氮作用,豆类作物相比其他农作物施用更少的氮肥,从而排放更少的氧化亚氮(N2O)。因此 ...
许俊武
core  

Bimetallic NiCo Loaded on the Nitrogen‐Rich Modified Lignin‐Derived Carbon Coordination Network for Accelerated Oxygen Reduction Kinetics

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT The development of novel oxygen electrocatalysts with cost‐effectiveness, scalability, high catalytic activity, and stability presents a significant challenge for zinc–air batteries (ZABs). The nitrogen‐rich lignin coordination network structure is synthesized through amine modification of lignin.
Ping‐Xian Feng   +8 more
wiley   +1 more source

同位素技术在内陆河水循环研究中的应用前景 [PDF]

open access: yes, 2007
介绍了同位素技术的原理,初步探讨并提出了同位素技术应用在气候变化对内陆河流域水循环影响研究中的思路和重点,主要包括水汽来源分析、区域降水线与蒸发线特征分析、氘盈余的分布特征及古气候信息的提取等方面。通过创新气候变化背景下的内陆河流域水循环变化的研究模式 ...
宋郁东, 毛炜峄, 陶辉, 韩俊
core  

An Asymmetric Sandwich‐Structured Hydrogel Enables High‐Output Stable Moist–Electric Generation and Self‐Powered Sensing

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Moisture‐enabled electricity generation technology offers a new paradigm for sustainable energy harvesting, but its practical applications are still limited by issues such as low output power and insufficient long‐term stability. In this paper, an asymmetric sandwich‐structured hydrogel moist–electric generator (SSHMEG) with an ion ...
Peng Chen   +7 more
wiley   +1 more source

The existing states and evolution of P and Fe in shallow sediments from the continental slope of northern South China Sea and their indication for the decomposition of gas hydrate [PDF]

open access: yes, 2016
天然气水合物作为当前极具开发潜力的新型清洁能源,受到科学界的广泛关注。海平面下降、洋壳的构造运动、海底沉积物滑塌及洋底水温变化等都可能造成天然气水合物的失稳分解,分解释放的CH4在垂向运移过程中与上层电子受体发生AOM,使SMTZ等作用带磷铁的赋存形态发生变化。磷作为海洋生物的重要营养元素,在海洋生物地球化学循环中有着重要意义,与铁、硫元素及沉积有机质关系紧密,在早期成岩过程中扮演了重要角色;而铁作为地壳中丰度最高的氧化还原敏感性金属元素,在海洋沉积物中的氧化还原过程对磷、硫 ...
杨鸣
core  

The Power of Framing: Institutional Policy Entrepreneurship in the EU's Wildfire Risk Management (WFRM)

open access: yesEuropean Policy Analysis, Volume 12, Issue 2, Spring 2026.
ABSTRACT This article explains why the European Union Wildfire Risk Management instruments have evolved since the 1980s, even though the underlying patterns of wildfire events have remained largely unchanged. It argues that these changes stem from competing institutional actors promoting distinct policy frames within the European Union's (EU ...
Damien Ballereau, Sabine Saurugger
wiley   +1 more source

气候变化及生态建设措施对宁夏典型入黄流域径流变化影响

open access: yesShuitu Baochi Xuebao, 2023
为分析气候变化及植被和淤地坝等生态建设措施对径流变化的影响,选取宁夏典型入黄流域清水河和苦水河为研究对象,采用Pettitt突变方法分析研究流域气象水文和生态建设措施等要素的变异点,基于Budyko理论,通过建立水热耦合控制参数与生态建设措施的多元线性回归方程,构建耦合生态建设措施下的降水-径流模型,并对模型进行适用性评估,采用弹性系数法,量化不同生态建设措施对径流变化的贡献率。结果表明:研究流域径流均呈减小趋势,且年径流突变均发生在2000年;水热耦合控制参数与NDVI和淤地坝指数呈显著的正相关关系 ...
于坤霞   +8 more
doaj  

Growing Demand and Uneven Supply: Eight Years of Nature Education in China 需求增长与供给不均:中国自然教育八年发展回顾

open access: yesIntegrative Conservation, Volume 5, Issue 1, Page 46-58, March 2026.
ABSTRACT This study examines the role of nature education in advancing conservation and sustainability in China between 2014 and 2023. Drawing on national survey reports and historical–comparative methods, it analyses the dynamics of public demand, institutional supply, and practitioner capacity.
Qi Yunxi, Lyu Xiang, Huang Yu
wiley   +1 more source

黄前库区森林地表径流水移动规律的研究

open access: yesShuitu Baochi Xuebao, 2004
通过对黄前库区流域森林主要类型刺槐林和油松林土壤结构状况和渗透性能的比较,研究了不同森林类型地表径流水的移动规律。在自然降雨后,以1m×1m为基本单位推算其可能产生的地表径流量,根据实际径流量推算地表径流水在径流过程中下渗的数量。研究结果表明:刺槐林的森林土壤结构相对较好,地表径流水下渗的速度较快,而流速较慢,因而产生的地表径流量较少;而油松林,特别是阳坡油松林的土壤结构较差,地表径流水下渗的速度较慢,而流速较快,因而产生的地表径流量较大。
李德生 张萍 张水龙 朱殿兴 鲁法典
doaj   +2 more sources

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