1,725,060 research outputs found
Li Xia de ren wu hua yan jiu Li Xia de ren wu hua zhan lan tu lu = Figure paintings by Li Xia = Figure paintings by Li Xia
No full textFrom Bedrock to Sediments: Insights on the Ross Sea Ice-Flow Dynamics Inferred from Detrital Data
Full text linkThe Ross Sea received about one third of the Antarctic ice. It is a crucial area to investigate the ice dynamics during the Cenozoic as it records the evolution of both the East Antarctic Ice Sheet (EAIS) and West Antarctic Ice Sheet (WAIS), whose variations are a direct response to climate change. Reconstructions of the ice flow models are mainly based on multi-proxy provenance analysis of glacigenic sediments but so far, a well-established model is not existing. There are still disputes of the different ice contribution between the EAIS and the WAIS, and the ice confluence in the Ross Sea. Thus, the main target of this study is to provide new inputs to build a robust model of Ross Sea ice flow during the Cenozoic.
This work is based on 48 samples collected across the Ross Sea and analyzed by apatite fission track (AFT) dating. More in detail, a first set of 16 samples is from the drilling core CIROS-2, whose stratigraphic range is from early Pliocene to Quaternary. A second group of 32 samples derives from 18 post-Late Glacial Maximum (LGM) piston cores drilled across the Ross Sea. The obtained fission-track data have been modelled with statistical tools (among them, the Multidimensional Scaling) and finally interpreted in terms of thermal evolution by the HeFTy software.
The AFT age data of CIROS-2 samples show a large range of ages but most of the grains fit well with two main age components at 24-42 Ma and 43-70 Ma whereas the other components are not regularly distributed through the well. This pattern indicates a mixture of provenance from different areas along the Transantarctic Mountains (TAM). Furthermore, it suggests glacial expansion over the McMurdo Sound during the Pliocene, and periodically ice invading and retreating in Pleistocene.
The data of post-LGM piston cores samples also show a large range of individual grain ages. The lack of systematic trends across the Ross Sea indicates the presence of multiple sources with a complex and differentiated erosional history. The presence of apatites younger than 21 Ma, clearly of volcanic origin, such as ages older than 230 Ma represent a significant signature for a source related to evolution of East Antarctica. Moreover, thermal modelling and the presence of apatites with cooling ages of about 30-40 Ma reveal a main exhumation phase of the TAM during the Oligocene associated to the last phases of the West Antarctic Rift System. The spatial distribution of key marker apatites (e.g. younger than 21 Ma or older than 230 Ma) allows to identify the Central High as a major ice-flow divide. West of the Central High, the ice flow is from East Antarctica, with general northwards trend but with local flows from outlet glaciers, especially during ice sheet retreat phases. East of the Central High, sediments derived mainly by West Antarctica, with only minor contributions from the southernmost portion of the TAM and the lack of any significant input from the inner Marie Byrd Land.
As a whole, this work supports the idea of a WAIS-dominated ice flow model during the early Pliocene, an EAIS-dominated ice flow model during the late Pleistocene and an EAIS-WAIS balanced ice flow model during the Last Glacial Maximum
Mitigating spatial conflict of land use for sustainable wetlands landscape in Li-Xia-river region of central Jiangsu, China
No full textLi-Xia-river Wetlands make up the biggest freshwater marsh in East China. Over the last decades, social and economic developments have dramatically altered the natural wetlands landscape. Mitigating land use conflict is beneficial to protect wetlands, maintain ecosystem services, and coordinate local socioeconomic development. This study employed multi-source data and GIS-based approaches to construct a composite index model with the purpose of quantitatively evaluating the intensity of land use conflict in Li-Xia-river Wetlands from 1978 to 2018. The results showed that the percentage of the wetlands’ area declined from 20.3% to 15.6%, with an overall reduction rate of 23.2%. The mean index of land use conflict increased from 0.15 to 0.35, which suggests that the conflict intensity changed from “no conflict” to “mild conflict.” The number of severe conflict units increased by about 25 times. A conspicuous spatial variation of land use conflict was observed across different periods, although taking land for agricultural activities was the overriding reason for wetlands reduction. However, in recent years, urban sprawl has posed the greatest threat to Li-Xia-river Wetlands. Coordinating land use conflict and formulating a practical strategy are the initial imperative steps to mitigate the threat to wetlands
Mitigating Spatial Conflict of Land Use for Sustainable Wetlands Landscape in Li-Xia-River Region of Central Jiangsu, China
No full textLi-Xia-river Wetlands make up the biggest freshwater marsh in East China. Over the last decades, social and economic developments have dramatically altered the natural wetlands landscape. Mitigating land use conflict is beneficial to protect wetlands, maintain ecosystem services, and coordinate local socioeconomic development. This study employed multi-source data and GIS-based approaches to construct a composite index model with the purpose of quantitatively evaluating the intensity of land use conflict in Li-Xia-river Wetlands from 1978 to 2018. The results showed that the percentage of the wetlands’ area declined from 20.3% to 15.6%, with an overall reduction rate of 23.2%. The mean index of land use conflict increased from 0.15 to 0.35, which suggests that the conflict intensity changed from “no conflict” to “mild conflict.” The number of severe conflict units increased by about 25 times. A conspicuous spatial variation of land use conflict was observed across different periods, although taking land for agricultural activities was the overriding reason for wetlands reduction. However, in recent years, urban sprawl has posed the greatest threat to Li-Xia-river Wetlands. Coordinating land use conflict and formulating a practical strategy are the initial imperative steps to mitigate the threat to wetlands
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparing the mental health of rural-to-urban migrant children and their counterparts in China
No full textBackground: In recent years, the issue of migrant children with peasant parents working in cities has attracted widespread attention in recent years because of the sheer number and the benefits bundled in China's household. The focus has gradually extended from early education opportunities to all aspects of physical and mental development, especially the social adaptation and mental health of migrant children. The negative impact of environment changes on migrant children' mental health is very worrying for parents and the society. Some studies have found that immigrant children's mental health is significantly lower than their peers, but there are also studies that hold the opposite view. Thus, the mental health status of migrant children is still a controversial issue, which may have a certain relationship with the potential differences in the specific problems of mental health, regions, comparison objects, and researchers. The objective of this protocol is to investigate whether mental health and subdimensions differ between rural-to-urban migrant children and their counterparts living in China and examine study characteristics that might result in differences among studies. Methods: We will search PubMed, Embase, OVID, ERIC, Web of Science, and Chinese databases including CNKI, Chongqing VIP, and Wan Fang data from start to April 2018. Cross-sectional studies with a comparison of migrant children and their counterparts will be included. The primary outcome will be the mean and standard deviation of mental health and its sub-dimensions. Standardized mean difference is used as the main effect value. Subgroup analyses will be carried out by the location of studies and school type of. Sensitivity analyses will be conducted to assess the robustness of the findings. Analyses will be performed with RevMan and Stata software. Results: This systematic review and meta-analysis will compare the mental health status of rural-to-urban migrant children and their counterparts living in China. Conclusion: The results of this systematic and meta-analysis will be helpful to get a more reliable understanding of the mental health of rural-to-urban migrant children and the reasons for the controversy on this issue.</p
Tomicus armandii Li & Zhang (Curculionidae, Scolytinae), a new pine shoot borer from China
No full textLi, Xia, Zhang, Zhen, Wang, Hongbin, Wu, Wei, Cao, Peng, Zhang, Peiyi (2010): Tomicus armandii Li & Zhang (Curculionidae, Scolytinae), a new pine shoot borer from China. Zootaxa 2572: 57-64, DOI: 10.5281/zenodo.19743
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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