Results 51 to 60 of about 15,228 (165)

Mercury isotope fractionation during the processes of a seawater desulfurization coal-fired power plant and isotopic tracing of mercury pollution in surrounding atmospheric [PDF]

open access: yes, 2016
汞是一种全球性的有毒重金属元素,由于形态多变,其生物地球化学循环过程十分复杂。大气中的汞主要来自于人类活动,燃煤是最主要的汞排放源。目前,海水脱硫工艺广泛应用于我国沿海地区的燃煤电厂中。与其他脱硫工艺不同,配备海水脱硫系统燃煤电厂的汞排放除了通过烟气排入大气外,还包括不可忽略的脱硫海水中的汞向大气的迁移扩散。因此,研究配备海水脱硫系统的燃煤电厂的汞排放特征对周边大气的影响,具有十分重要的意义。 本研究以厦门市一座配备有典型海水脱硫系统的燃煤电厂(SY电厂)的周边大气环境作为研究区域 ...
黄舒元
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A Brief Analysis of the Acrostic in Chinese Language in Teaching Chinese as a Foreign Language [PDF]

open access: yes, 2014
Acrostic is a special phenomenon of the modern Chinese language. It is a combination of lexical and syntactical that across “vocabulary” and “grammar” categories.
Agustian, A. (Agustian)   +1 more
core   +2 more sources

Predictions of southern migration timing in coastal sharks under future ocean warming

open access: yesConservation Biology, Volume 39, Issue 6, December 2025.
Abstract Projected redistribution of marine species due to ocean warming may undermine current conservation efforts. Yet, there have been few studies on how ocean warming may alter migration timing. Across 5 years of acoustic telemetry data (2018–2022), we determined environmental drivers of southward migration timing for 6 migratory shark species from
Maria H. Manz   +16 more
wiley   +1 more source

用预放电电流法测量SF6和SF6/CO2气体的离子迁移率

open access: yesGaoya dianqi, 1998
用预放电电流法测量了SF6气体以及SF6/CO2混合气体的正负离子迁移率。实验数据表明,正负离子迁移率只是E/p的函数,SF6/CO2混合气体的正负离子迁移率随CO2含量的增加而增大。
王沛, 王中方, 张乔根, 邱毓昌
doaj  

典型山地丘陵区农业小流域氮素迁移特征

open access: yesShuitu Baochi Xuebao, 2020
为探讨山地丘陵区农业小流域氮素迁移特征,对典型山地丘陵区农业小流域降雨—径流事件、水体氮素形态与浓度、时间变异特征及其迁移通量进行了全年观测研究。结果表明:(1)小流域水体氮素浓度存在显著季节变异特征,全年总氮(TN)平均浓度为2.14 mg/L,硝态氮(NO3-—N)平均浓度为0.77 mg/L,铵态氮(NH4+—N)平均浓度为0.25 mg/L,溶解性有机氮(DON)平均浓度为0.51 mg/L,其中NO3-—N是氮素迁移的主要形态;(2)小流域春季(3—5月)对全年氮素迁移通量贡献最高(43.56%
李红   +4 more
doaj  

Threshold responses of floating meadow fish communities to floodplain forest cover in the lower Amazon River

open access: yesConservation Biology, Volume 39, Issue 6, December 2025.
Abstract Forest cover is positively associated with fish biomass and fisheries yield in the Amazon River floodplain, and many species enter flooded forests to feed, spawn, or seek refuge from predation. Floating macrophyte beds, known as floating meadows, in Amazon floodplains support high fish diversity and serve as nursery habitat for many fishes of ...
Sam Grinstead   +6 more
wiley   +1 more source

IL-6 promotes Epithelial-Mesenchymal Transition and increases metastasis in lung cancer cells via the activation of ATM/NF-kappaB pathway [PDF]

open access: yes, 2015
【背景和目的】恶性肿瘤的侵袭和转移是导致治疗失败的关键因素。IL-6作为重要的促炎因子,参与了肿瘤发生发展的全过程,是肿瘤相关炎症的关键分子。我们之前的研究发现,IL-6可以在肺癌中激活ATM-NF-κB通路、促进MMPs的表达及活性,并可以介导肿瘤细胞的侵袭和迁移。肿瘤转移涉及肿瘤微环境各组分的相互作用,包括肿瘤细胞自身发生了形态、极性、能动性改变,即上皮间质转换(EMT)的发生。EMT赋予细胞迁移和侵袭以及诱导为干细胞的性质,阻止了细胞的衰老和凋亡,并促成了免疫抑制微环境的形成 ...
姜伊娜
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The Role of Matrine and Mitogen-Ativated Protein Kinase/Extracellular Signal-Regulated Kinase Signal Transduction in the Inhibition of the Proliferation and Migration of Human Umbilical Veins Endothelial Cells Induced by Lung Cancer cells [PDF]

open access: yes, 2009
Background and objective Matrine, one of the major alkaloid components of the traditional Chinese medicine Sophora roots, has a wide range of pharmacological effects including anti-inflammatory activities, growth inhibition and induction of cell ...
Jinchang LU   +5 more
core  

单次和间歇性降雨下紫色土坡地壤中硝氮迁移特征

open access: yesShuitu Baochi Xuebao, 2022
为探究不同降雨条件下不同观测时期硝氮在紫色土坡地中的迁移特征, 通过室内土槽和人工模拟降雨装置, 设置单次降雨和间歇性多次(12次)降雨条件, 分别探讨短时期和长时期下的紫色土壤中硝氮迁移特征。结果表明: 在单次降雨后短期内紫色土坡地距地表 15 cm处土壤水和硝氮均匀地向下距地表 35 cm土壤坡脚处迁移, 而在间歇性12次降雨条件下, 前6次降雨中观测点硝氮浓度由初始345.7 mg/L急速下降至99.7 mg/L; 第7次到第9次降雨过程中硝氮浓度由平均值69.7 mg/L缓慢减少至52.0 mg/
谢梅香   +5 more
doaj  

Approaching Usage Notes in English Advanced Learner's Dictionaries from the Perspective of Noticing Theory: The Case Study of the British ‘Big Five’ [PDF]

open access: yes, 2016
词汇用法信息的掌握是二语学习者语言能力的一个重要组成部分。学习词典作为专门为学习者设计的词典,应该提供充分和有益的用法信息以满足学习者的需求。用法信息的设置能有效地补充词义信息,因而也是决定词典质量的关键因素。大部分关于学习词典中用法信息的研究都专注于用法标签,专门针对用法说明的研究寥寥无几。此外,注意理论主要用于二语习得的研究,将该理论和词典编纂相结合是一个新的尝试,因此本文将填补这一空白。 为了探讨英语高阶学习词典中用法说明的设置,本文选取了五本具有代表性的英语高阶学习词典即“五大学习词典 ...
黄晓微
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