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1.
Psychol Res Behav Manag ; 16: 619-635, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36911044

RESUMO

Purpose: Based on the affective event theory and the theoretical framework of "work environment features-work events-emotional responses-work attitude", this study aims to explore how and when home-based telework negatively affects work engagement by focusing on the dual chain mediating paths of "workplace isolation-negative emotion" and "telepressure-negative emotion", and the moderating role of family-supportive leadership. Methods: A questionnaire survey was used to collect 276 self-reported responses from employees with home-based telework experience in China. Findings: (a) Home-based telework indirectly and negatively affects work engagement through the mediating chain of "workplace isolation-negative emotion"; (b) Home-based telework indirectly and negatively affects work engagement through the mediating chain of "telepressure-negative emotion"; (c) Family-supportive leadership negatively moderates the chain mediating effect of "workplace isolation-negative emotion" and "telepressure-negative emotion" between home-based telework and work engagement. In other words, the higher the level of family-supportive leadership, the weaker the negative effect of home-based telework on work engagement. Originality/Value: This study sheds additional light on the relationship between home-based telework and work engagement by constructing the influence mechanism model of home-based telework on work engagement, in which "workplace isolation-negative emotion" and "telepressure-negative emotion" act as chain mediators, and family supportive leadership as moderator. This study enriches the literature on home-based telework. Practical Implications: The findings indicates that home-based work has indirectly and negatively effects on work engagement through dual chain mediating paths of "workplace isolation-negative emotion" and "telepressure-negative emotion". However, family-supportive leadership can weaken this negative influence. Therefore, organizations need to cultivate family supportive leadership.

2.
Front Psychol ; 13: 1014195, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36524195

RESUMO

Introduction: Most previous studies focused on the antecedents of employee innovative behavior but rarely examined the outcomes of employee innovative behavior. Moreover, previous studies ignored the relationship between employee innovative behavior and workplace wellbeing. Based on social comparison theory and social exchange theory, this study introduces coworker ostracism and leader support for innovation as mediating variables to explore the "double-edged sword" effect of employee innovative behavior on workplace wellbeing. Methods: Based on a sample of 319 employees from Chinese companies, this study used SPSS 26.0 and MPLUS 8.3 to examine the hypotheses. Results: Empirical results demonstrate that (a) employee innovative behavior is directly and positively related to workplace wellbeing, (b) employee innovative behavior is indirectly and positively related to workplace wellbeing through leader support for innovation, and (c) the negative association between employee innovative behavior and workplace wellbeing via coworker ostracism is unsupported. Discussion: The findings of this study enrich the literature by exploring the double-edged sword effect of employee innovative behavior on workplace wellbeing. The practical implications of this study are that leaders in organizations should give employees innovation support.

3.
Sci Total Environ ; 636: 249-259, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29705437

RESUMO

Dissolved organic matter (DOM) is a crucial driver of various biogeochemical processes in aquatic systems. Thus, many lakes and streams have been investigated in the past several decades. However, fewer studies have sought to understand the changes in DOM characteristics in the waters of the Three Gorges Reservoir (TGR) areas, which are the largest artificial reservoir areas in the world. Thus, a field investigation of dissolved organic carbon (DOC) concentrations and of chromophoric dissolved organic matter (CDOM) properties was conducted from 2013 to 2015 to track the spatial-temporal variability of DOM properties in the TGR areas. The results showed that the alternations of wet and dry periods due to hydrological management have a substantial effect on the quantity and quality of aquatic DOM in TGR areas. Increases in DOC concentrations in the wet period show an apparent "dilution effect" that decreases CDOM compounds with relatively lower aromaticity (i.e., SUVA254) and molecular weight (i.e., SR). In contrast to the obvious temporal variations of DOM, significant spatial variability was not observed in this study. Additionally, DOM showed more terrigenous characteristics in the dry period but weak terrigenous characteristics in the wet period. Furthermore, the positive correlation between SUVA254 and CDOM suggests that the aromatic component controls the CDOM dynamics in TGR areas. The first attempt to investigate the DOM dynamics in TGR areas since the Three Gorges Dam was conducted in 2012, and the unique patterns of spatial-temporal variations in DOM that are highlighted in this study might provide a new insight for understanding the role of DOM in the fates of contaminants and may help in the further management of flow loads and water quality in the TGR area.

4.
J Environ Manage ; 206: 418-429, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29102844

RESUMO

Dissolved organic matter (DOM) plays an important environmental and ecological role in inland aquatic systems, including lakes. In this study, using fluorescence analysis, we investigated the seasonal dynamics of DOM characteristics in Changshou Lake, which is a typical inland lake in the Three Gorges Reservoir (TGR) area. We also discuss the environmental implications of DOM for mercury (Hg) dynamics. Based on the origins of two end-members, the variations in DOM observed in this study in Changshou Lake suggest that hydrological processes (e.g., terrestrial inputs resulting from runoff and humic-like component residences) and biological activities (e.g., microbial and algae growth) are the two main principal components controlling the seasonal dynamics of DOM characteristics. Furthermore, the dynamics of dissolved Hg co-varied with variations in DOM properties, rather than with dissolved organic carbon (DOC) concentrations. This indicates that the previously reported simple correlations between DOC and Hg were not comprehensive and may lead to misunderstanding the interactions between DOM and Hg. Therefore, we recommend that when using DOM-Hg correlations to evaluate the role of DOM in the environmental fate of Hg, especially in field investigations of the spatial and temporal distribution of Hg, the properties of DOM must be taken into account.


Assuntos
Monitoramento Ambiental , Mercúrio/análise , Carbono , Corantes , Fluorescência , Lagos , Compostos Orgânicos
5.
Huan Jing Ke Xue ; 37(3): 884-92, 2016 Mar 15.
Artigo em Chinês | MEDLINE | ID: mdl-27337878

RESUMO

The study of the molecular weight (MW) fractions of dissolved organic matter (DOM) in aquatic environment is of interests because the size plays an important role in deciding the biogeochemical characteristics of DOM. Thus, using ultrafiltration ( UF) technique combined with three-dimensional fluorescence spectroscopy, DOM samples from four sampling sites in typical water-level fluctuation zones of Three Gorge Reservoir areas were selected to investigate the differences of properties and sources of different DOM MW fractions. The results showed that in these areas, the distribution of MW fractions was highly dispersive, but the approximately equal contributions from colloidal (Mr 1 x 10³-0.22 µm) and true dissolved fraction (Mr < 1 x 10³) to the total DOC concentration were found. Four fluorescence signals (humic-like A and C; protein-like B and T) were observed in all MW fractions including bulk DOM, which showed the same distribution trend: true dissolved > low MW (Mr 1 x 10³-10 x 10³) > medium MW (Mr 10 x 10³-30 x 10³) > high MW (Mr 30 x 10³-0.22 µm). Additionally, with decreasing MW fraction, fluorescence index (FI) and freshness index (BIX) increased suggesting enhanced signals of autochthonous inputs, whereas humification index ( HIX) decreased indicating lowe humification degree. It strongly suggested that terrestrial input mainly affected the composition and property of higher MW fractions of DOM, as compared to lower MW and true dissolved fractions that were controlled by autochthonous sources such as microbial and alga activities, instead of allochthonous sources. Meanwhile, the riparian different land-use types also affected obviously on the characteristics of DOM. Therefore, higher diversity of land-use types, and also higher complexity of ecosystem and landscapes, induced higher heterogeneity of fluorescence components in different MW fraction of DOM.


Assuntos
Monitoramento Ambiental , Água Doce/química , Compostos Orgânicos/análise , Rios , Fracionamento Químico , China , Ecossistema , Fluorescência , Peso Molecular , Espectrometria de Fluorescência , Ultrafiltração
6.
Huan Jing Ke Xue ; 37(7): 2496-2505, 2016 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964455

RESUMO

Water-level fluctuation zone is an important area in Three Gorges Reservoir areas, because dissolved organic matter (DOM) releases from submerged soils is a crucial source of DOM in overlying waters when flooding occurs. But there was little qualitative and quantitative analysis for DOM. In this study, soils of four typical water-level fluctuation zones were selected to conduct simulated flooding experiment. Also, UV-Vis spectroscopy was utilized to investigate the DOM spectral characteristics in two individual flooding sets including ambient (open air) and anoxic conditions. The results showed, for all soils, the DOM release patterns all showed a "rapid release, then decrease, and final dynamic equilibrium" trend. Also, through calculations of DOM releasing rates and fluxes, DOM releases clearly showed a feature of "source-sink dynamic exchange". By comparison between two flooding treatments, although DOC and CDOM didn't show any significant differences, but higher aromaticity (SUVA280) was observed in anoxic experiment. In contrast, spectra slope ratio (SR) was insensitive to redox conditions of different flooding. Meanwhile, correlation between DOC and CDOM in anoxic was also higher than that in ambient flooding. Additionally, obvious differences among soils from different sampling sites were observed, Shibao Zhai (SB) of which showed the greatest releasing potential. Considering the various soil properties, soil organic matter amounts in soils is one of the key factors to explain the differences among sampling sites, but other geochemical factors should also be considered in the processes of DOM releases. Summarily, only focusing on the changes of DOC concentrations in submerging process is not enough to comprehensively describe the DOM release characteristics.

7.
Huan Jing Ke Xue ; 37(7): 2506-2514, 2016 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964456

RESUMO

As an important sources of dissolved organic matter (DOM) in aquatic system, DOM releases from flooding or submerged soils is a key process in water-level fluctuation zones. In this study, four typical sites in water-level fluctuation zones of Three Gorges Reservoir areas were selected to conduct simulated soil flooding experiments, under ambient (open air) and anoxic conditions. By using fluorescence spectrum technique, the dynamic and geochemical characteristics of DOM releases from flooding soils were investigated. Results showed that the trend or model of DOM releases observed by fluorescence spectrum in all soils from four sampling sites was similar to the observation by UV-Vis spectrum. Fluorescence property of DOM releases showed an important contribution to DOM fluorescence in overlying waters. The rapid releases at initial stage and removal mechanism for later dynamic equilibrium were crucial to explain the dynamic "source-sink" equilibrium in whole flooding period. Effect of inorganic mineral adsorption-desorption on humic-like components (A and C peaks) was significant. Also, impact of microbial utilization on protein-like components (B and T peaks) was confirmative. Additionally, all DOM samples had "autochthonousness plus allochthonousness" property. Except Shibaozhai (SB) site in Zhongxian county, during the whole flooding period, all three other sites didn't show any significant difference between ambient and anoxic conditions. They could be explained by the high heterogeneity of soil property including minerals and organic components. Meanwhile, both the UV-Vis and fluorescence spectra were complementary for each other, and they evidentially showed that the "source-sink" (release and removal) mechanism in DOM releases from submerged soils was the core to decide the dynamics of DOM in overlying waters. Importantly, DOM showed higher aromaticity and humification at the initial release stage when flooding occurred, as well as the greater terrestrial source characteristics, which further helped to explain the environmental fates of pollutants in these environmental sensitive areas. It would also be useful for unveiling the role of DOM in environmental system in future.

8.
Huan Jing Ke Xue ; 37(11): 4168-4178, 2016 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964667

RESUMO

For further understanding the geochemical characteristics of dissolved organic matter (DOM) in "reservoir-type" lake, in this study a typical "reservoir-type" lake, Changshou Lake located in inlands of Three Gorges Reservoir areas, was selected to investigate the composition, sources and spatial distributions of chromophoric DOM (CDOM) in this lake, through UV-Vis and three-dimensional fluorescence spectroscopy combined within analysis of riparian eco-system differences. The results showed that DOM concentrations including dissolved organic carbon (DOC) and CDOM abundance in different sampling sites varied spatially to a certain degree, in contrast to fluorescence component of DOM showing a constant level. In backwater zone (also called stagnant zone alternatively), due to accumulation of DOM and limited impact of terrestrial contribution, the endogenesis (autochthonous production) was the predominant geochemical process showing an obvious "authigenic-control" characteristic, and relatively lower aromaticity and molecular weight. In comparison, sampling sites surrounding artificial forests and tourism development, the highly humic (highly aromatic) substances resulted from terrestrial inputs were the main source, but discharge due to human activities was also responsible for highly protein-like component observed in DOM. Additionally, in the entry zones of lake from upstream river, DOM was affected by fruit plantations and residences, contribution from upstream river could also be neglected. From the other aspects, some significant correlations were also observed, which were independent of riparian eco-system differences, for example, the SUVA280 versus S(275-295) (negative), CDOM versus FDOM (positive), and CDOM and S(275-295) (negative), indicating the correlation was an intrinsic property of DOM that could not be affected by the surrounding environment. Meanwhile, the main chromophoric component of CDOM in Changshou Lake was high molecular weight (HMW) components within highly aromatic structures. At least, 51% of CDOM dynamic could be explained by changes of FDOM, especially in backwater zone the co-variance was more obvious. Furthermore, when the traditional fluorescence index (FI) could not comprehensively explain the differences of DOM sources due to very similar (statistically insignificant) values, integration of UV-Vis and fluorescence spectral characteristics and detailed discussion of riparian eco-system differences, might be an important way to help further resolution of DOM composition and sources in aquatic environments, such as lake, river and watershed.

9.
Huan Jing Ke Xue ; 37(6): 2082-2092, 2016 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964873

RESUMO

As a key geochemical factor in earth system, dissolved organic matter (DOM) plays an important role in controlling environmental quality of watersheds. In this study, a typical agricultural watershed of Three Gorges reservoir areas, Wangjiagou watershed in Fuling district of Chongqing, was selected to characterize DOM in waters through fluorescence and UV-Vis spectroscopy, while the effect of land-use types in this watershed was discussed. The results showed large spatial variances of aquatic DOM in this watershed, with significant differences in compositions and sources. After calculation of ag*(355) for indicating proportion of chromophoric DOM in bulk DOM, the order of DOM was paddy rice field> ditch> pond> well> outlet point. DOM samples from paddy rice field and ditch showed higher SUVA254 suggesting higher aromaticity. DOM from this watershed showed 2 typical types (4 peaks A, C, B and T) of fluorescent components including humic-like and protein-like components. Dual contributions from autochthonous (e.g., microbial or alga production) and allochthonous both heavily affected the DOM characteristics. Besides active microbial activities due to high organic and nutrients inputs from agricultures, discharge of sewage and water used in agricultural production could contribute proteins possibly inducing ascending proportion of protein-like component as shown in fluorescence analysis. DOM samples from the same sampling points but in different crop plantation seasons were collected to compare, for understanding the differences between two planting seasons. It clearly suggested protein-like component was the key variable to control the DOM dynamics. After land-use changing from rice/corn into mustard plantation, all of DOC, CDOM and r(T/C)showed significant differences, but no such observations were observed in FI, BIX and r(A/C).


Assuntos
Agricultura , Microbiologia Ambiental , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , China , Estações do Ano , Espectrometria de Fluorescência , Análise Espectral
10.
Ying Yong Sheng Tai Xue Bao ; 26(3): 666-74, 2015 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-26211046

RESUMO

CO2, N2O and CH4 are important greenhouse gases, and soils in forest ecosystems are their important sources. Carya cathayensis is a unique tree species with seeds used for high-grade dry fruit and oil production. Understory vegetation management plays an important role in soil greenhouse gases emission of Carya cathayensis stands. A one-year in situ experiment was conducted to study the effects of understory removal on soil CO2, N2O and CH4 emissions in C. cathayensis plantation by closed static chamber technique and gas chromatography method. Soil CO2 flux had a similar seasonal trend in the understory removal and preservation treatments, which was high in summer and autumn, and low in winter and spring. N2O emission occurred mainly in summer, while CH4 emission showed no seasonal trend. Understory removal significantly decreased soil CO, emission, increased N2O emission and CH4 uptake, but had no significant effect on soil water soluble organic carbon and microbial biomass carbon. The global warming potential of soil greenhouse gases emitted in the understory removal. treatment was 15.12 t CO2-e . hm-2 a-1, which was significantly lower than that in understory preservation treatment (17.04 t CO2-e . hm-2 . a-1).


Assuntos
Dióxido de Carbono/análise , Carya , Agricultura Florestal/métodos , Metano/análise , Óxido Nitroso/análise , Solo/química , Carbono , Florestas , Gases , Efeito Estufa , Estações do Ano , Água
11.
Huan Jing Ke Xue ; 36(1): 151-62, 2015 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-25898659

RESUMO

Ultraviolet-visible (UV-Vis) absorption spectroscopy and three-dimensional fluorescence spectroscopy, combined with fluorescence regional integration were conducted to investigate the geochemical characteristics of DOM extracted from soils of water-level fluctuation zones of the Three Gorges Reservoir Region. The results showed that the average CDOM concentrations in soils were in order of Zhongxian > Fengdu > Fuling > Wanzhou > Wushan > Yunyang > Fengjie > Kaixian. Additionally, in Zhongxian, Fengdu and Fuling, the CDOM concentration [a (355)], aromaticity (SUVA254) and hydrophobicity (SUVA260) were all much higher than those at the other sampling sites, but the humification index (HIX) was lower. Four fluorophores were observed in all soil DOM samples, including three humic-like fluorescence peaks (A, C and M respectively) and one tryptophan-like fluorescence peak (T). Proportion of fluorescence regional integration of ultraviolet region humic-like A fluorophore was the highest as compared with the others. More importantly, tryptophan-like fluorophore (T) and a(355) showed significant correlation (r = 0.674, P < 0.01), indicating the variance of CDOM concentration was possibly dependent on T fluorophore. Meanwhile, the total integrated fluorescence intensity(TOT) of 3D- EEM was an appropriate parameter to characterize the total contributions of fluorophores in DOM. Furthermore, the humification degree of DOM in soils was low in comparison with higher biological availability. Conclusively it seemed that the influence of "alternation of wetting and drying" resulted from water-level fluctuation on the geochemical characteristics of soil DOM was not significant as expected. It might be related to local agricultural activity, littoral plant growth and DOM mineralization process.


Assuntos
Água Doce/química , Compostos Orgânicos/análise , Solo/química , China , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Fluorescência
12.
J Hazard Mater ; 246-247: 135-44, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23298739

RESUMO

Amorphous TiO(2) (Am-TiO(2)) was prepared at room temperature by hydrolysis of Ti(OBu)(4) in water without addition of strong acids or organic solvents. Results from XRD and TEM revealed that the as-prepared Am-TiO(2) was composed of amorphous structure. For the simultaneous photosensitized removal of Cr(VI) and zwitterionic Rhodamine B (RhB) dye, Am-TiO(2) exhibited more significant synergistic effect than commercial P25-TiO(2). The removal efficiencies for RhB and Cr(VI) after 100 min visible light irradiation were 97.8% and 53.5% on Am-TiO(2), respectively. While 88.2% RhB and 42.1% Cr(VI) were removed on P25-TiO(2). Decreased synergistic activities as well as smaller surface areas were observed when Am-TiO(2) was pretreated at high temperatures (200-700°C). Thus, it was the larger specific surface area rather than better crystallinity dominated the synergistic degradation dynamics under visible light irradiation with lower pH (2), greater catalyst loading amount (2g/L), proper RhB/Cr(VI) ratios (1:8) and higher light intensity (500 W). Better synergistic performance was also obtained on Am-TiO(2) than P25-TiO(2) when Cr(VI) coexists with cationic dyes, while negligible difference was observed in the presence of anionic dyes. Superior stability and simplicity of Am-TiO(2) was also exhibited in the cyclic runs.


Assuntos
Cromo/isolamento & purificação , Rodaminas/isolamento & purificação , Titânio/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Catálise , Cromo/química , Cromo/efeitos da radiação , Concentração de Íons de Hidrogênio , Oxirredução , Rodaminas/química , Rodaminas/efeitos da radiação , Luz Solar , Termodinâmica , Poluentes Químicos da Água/química , Poluentes Químicos da Água/efeitos da radiação
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