Results 11 to 20 of about 4,473 (155)

Contribution of hybridization between polar bears and grizzly bears to polar bear extinction 北极熊和灰熊的杂交对北极熊灭绝的促进

open access: yesWildlife Letters, Volume 1, Issue 4, Page 178-193, December 2023., 2023
Genetic analysis by scientists of hybridization events from 2006 to 2010 indicates one‐directional gene flow from polar bears to grizzly bears. Even if gene flow was later discovered from grizzly bears to polar bears, there is not enough time to allow for significant adaptation to a rapidly changing Arctic environment.
Craig L. Shafer
wiley   +1 more source

Transdermal drug delivery in horses: An in vitro comparison of skin structure and permeation of two model drugs at various anatomical sites

open access: yesVeterinary Dermatology, Volume 34, Issue 3, Page 235-245, June 2023., 2023
Background – Oral and parenteral drug delivery in horses can be difficult. Equine‐specific transdermal drug formulations offer improved ease of treatment; development of such formulations requires a deeper understanding of the structural and chemical tissue barrier of horse skin. Hypothesis/Objectives – To compare the structural composition and barrier
Samuel C. Bizley   +3 more
wiley   +1 more source

Permeability and Protest in Lane 49: Entangling Materialities of Place with Housing Activism in Shanghai

open access: yesAntipode, Volume 53, Issue 1, Page 222-241, January 2021., 2021
Abstract Since China’s implementation of a neo‐liberal housing regime, housing activism has boomed. Whilst activism is ultimately in place, as increasingly recognised within protest work, there is limited reflection upon how permeable material histories are entangled with the throwntogetherness of place as a site for protest. Employing ethnography over
Harriet Larrington‐Spencer   +2 more
wiley   +1 more source

Dynamic Simulation of Soil Moisture Under Typical Land Preparation in Semi-arid Loess Area Using HYDRUS-1D Model [PDF]

open access: yes, 2023
[Objective] The dynamic characteristics of soil moisture under different land preparation measures were analyzed in order to provide a scientific basis for assessing the eco-hydrological benefits of slope land preparations and for promoting vegetation ...
Dong Hongxia, Wei Qiang, Zhang Qindi
core   +1 more source

气相阻力与土壤容重对一维垂直入渗影响的定量分析

open access: yesShuitu Baochi Xuebao, 2005
分析了土壤容重和气阻对一维垂直积水入渗的入渗率、累积入渗量以及湿润锋的影响,并对入渗过程中土壤平均含水率增量进行了研究。容重和气阻均对入渗率、累积入渗量和湿润锋有明显的影响:容重增加导致累积入渗量减少的减渗率在入渗过程中为一常数,相对于容重为1.3g/cm3土壤的累积入渗量,容重为1.4g/cm3和1.5g/cm3土壤的减渗率分别为31.79%和52.03%。容重增加导致湿润锋减少的减渗率在入渗过程中并非一常数,受到了入渗时间的影响;气阻导致累积入渗量和湿润锋减少的减渗率随基准入渗量的增加而变大 ...
张振华 谢恒星 刘继龙 蔡焕杰
doaj   +2 more sources

具有砂质夹层的土壤连续函数入渗模型

open access: yesShuitu Baochi Xuebao, 2007
实验研究表明,在具有砂质夹层土壤的积水入渗过程中,其累积入渗量随时间的变化存在着由非线性入渗关系逐渐转入线性稳定入渗的两个阶段.在已有的研究成果中,对此入渗过程大多采用以进入稳渗阶段的时间为界,分段对其进行数学模拟.本文提出将地表入渗通量随时间的变化视为两部分入渗过程叠加的思路,即一部分视为稳定入渗,其稳渗率与转入稳渗阶段后的量值相等;另一部分视为满足上层土体储水需求的非稳定入渗,其入渗率为入渗时间的函数,并在整个入渗过程进入稳定入渗阶段时,其量值趋近于零.在此思路与假设前提下 ...
张建丰, 王文焰, 贾中华
doaj   +2 more sources

Influence of mining-induced ground fissures on soil infiltration characteristics and its erosion effect in coal mining area of northern Shaanxi in the middle reaches of the Yellow River [PDF]

open access: yes
Cracking the soil and water loss effects of mining-induced surface fissures in the coal mining area of the middle reaches of the Yellow River is of great significance for ecological environment protection and high-quality development in the coal mining ...
Baodeng CHEN   +6 more
core   +1 more source

Effects on Atmospheric Influence Depth for an Anchored Vegetation Reinforcement System to Protect Newly Excavated Expansive Soil Slopes [PDF]

open access: yes, 2022
[Objective] The data that could provide a reference basis for the application of an anchor-reinforced vegetation system (ARVS) were obtained to protect newly excavated slopes with expansive soil.
Chen Junting, Tang Linqiang, Xu Yingzi
core   +1 more source

放牧对希拉穆仁草原土壤入渗过程影响的定量评估

open access: yesShuitu Baochi Xuebao, 2022
为定量评估放牧对草原土壤入渗的影响,了解和防治放牧造成的水土流失,科学评估草原水文调节功能,采用双环入渗法研究了放牧对典型草原土壤入渗性能的影响,并收集影响土壤入渗的环境特征变量。结果表明:(1)土壤入渗能力均受到放牧活动的干扰,随着放牧强度的增加,土壤初渗速率、稳渗速率减小, 达到稳渗时的历时缩短,而轻度放牧对土壤入渗性能却具有增强作用,LG的初渗速率(5.12 mm/min)、稳渗速率(1.93 mm/min)、2 h累积入渗量(213.42 mm)均较好, 快速入渗至稳渗阶段历时延长。(2 ...
耿林昇   +4 more
doaj  

Study on hydrogeochemical process in coastal zone and subterranean estuary of Qianhu Bay [PDF]

open access: yes, 2015
海底地下水排泄(SGD)作为海岸带陆海相互作用研究的热点之一,不仅是全球水循环的重要组成部分,更在海洋物质收支平衡中扮演着重要角色。地下河口(STE)作为地下水排泄入海的重要通道,存在地下水与海水机械混合的同时,还发生着许多生物地球化学反应,改变原来地下水的化学组成,使计算地下水输送入海的物质通量变得更为复杂。因此,了解各化学成分在地下河口处的空间分布特征和迁移演化规律,是合理评估地下水对近海生态环境影响的关键环节。 本文是在国家自然科学基金“海底地下水排泄(SGD)的地球化学过程 ...
王博
core  

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