Engineered nanomaterials in soil: Sources of entry and migration pathways

2013 ◽  
Vol 68 (3) ◽  
pp. 129-134 ◽  
Author(s):  
M. M. Gladkova ◽  
V. A. Terekhova
Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 773
Author(s):  
Ilona Szumańska ◽  
Sandra Lubińska-Mielińska ◽  
Dariusz Kamiński ◽  
Lucjan Rutkowski ◽  
Andrzej Nienartowicz ◽  
...  

Invasive alien species (IAS) is a global problem that largely relates to human activities and human settlements. To prevent the further spread of IAS, we first need to know their pattern of distribution, to determine which constitutes the greatest threat, and understand which habitats and migration pathways they prefer. Our research aimed to identify the main vectors and distribution pattern of IAS of plants in the city environment. We checked the relations between species distribution and such environmental factors as urban soil type and habitat type. We applied data on IAS occurrence (collected in the period 1973–2015) in 515 permanent plots with dimensions of 0.5 × 0.5 km and analyzed by direct ordination methods. In total, we recorded 66 IAS. We found a 27% variance in the IAS distribution pattern, which can be explained by statistically significant soil and habitat types. The most important for species distribution were: river and alluvial soils, forests and related rusty soils, and places of intensive human activities, including areas of urbisols and industriosols. Our results provide details that can inform local efforts for the management and control of invasive species, and they provide evidence of the different associations between natural patterns and human land use.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 667
Author(s):  
Yanxia Lu ◽  
Qing Peng ◽  
Chenguang Liu

The α-decay of incorporated actinides continuously produces helium, resulting in helium accumulation and causing security concerns for nuclear waste forms. The helium mobility is a key issue affecting the accumulation and kinetics of helium. The energy barriers and migration pathways of helium in a potential high-level nuclear waste forms, La2Zr2O7 pyrochlore, have been investigated in this work using the climbing image nudged elastic band method with density functional theory. The minimum energy pathway for helium to migrate in La2Zr2O7 is identified as via La–La interstitial sites with a barrier of 0.46 eV. This work may offer a theoretical foundation for further prospective studies of nuclear waste forms.


RSC Advances ◽  
2019 ◽  
Vol 9 (17) ◽  
pp. 9640-9653 ◽  
Author(s):  
Anna Borowska-Centkowska ◽  
Xi Liu ◽  
Marcin Krynski ◽  
Marzena Leszczynska ◽  
Wojciech Wrobel ◽  
...  

Total neutron scattering analysis and ab initio MD simulations reveal details of oxide ion vacancy ordering and migration pathways.


2020 ◽  
Vol 4 (2) ◽  
pp. 71-86
Author(s):  
Holm David

Over two decades ago, Jerold Edmondson and Li Jinfang conducted linguistic fieldwork in the China–Vietnam borderlands, and posited the existence of a migration corridor running between Guizhou province and the northern provinces of Vietnam, passing through the eastern part of Yunnan. This hypothesis was based on linguistic evidence, so they called it the language corridor, and looked at the correspondences between the speech of isolated communities in northern Vietnam and speech varieties in Guizhou, Guangxi and Yunnan. Historic migrations of populations, large and small, bring with them other traces of their original homelands. In the case of the Tai-speaking peoples of the China–Vietnam area, the evidence includes local varieties of vernacular character scripts based on Chinese. This article will present new information based on survey evidence, and propose a new enhancement of established methods in historical anthropology and historical linguistics.


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