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• The framework combines a cloud-edge-end structure to break the information barriers of multi-source measured data. • The method executes different strategies according to voltage levels based on interaction of edge computing is proposed. • Harmonic source identification and evaluation are achieved through the multi-level interaction of edge computing. • TVE, CMHSE and HHSE method for cloud-edge-end collaborative computing strategy are developed into the system. With the increase of power electronic devices such as distributed renewable energies, energy storage, and flexible loads, the disturbance sources are rapidly raised and distributed in multiple voltage levels in the distributed network. The harmonics they produce are random and uncertain, and the massive amounts of data propose high demands on server computing capability, which restrict harmonic sources evaluation and significantly influence the judgments of the power quality in the distribution network. In order to improve the power quality and the harmonic source evaluation function of the distribution network, in this paper, a framework for multi-harmonic source identification and evaluation based on cloud-edge-end collaboration is proposed. Firstly, based on the analysis of the functional requirements harmonic sources evaluation in multiple voltage levels, a novel framework of cloud-edge-end collaboration is proposed. Secondly, the cloud-edge-end collaborative harmonic sources evaluation method which executes different service strategies according to voltage levels and grid operation based on the multi-level interaction of edge computing is proposed. Further, the working principle of the proposed novel framework with multiple evaluation methods including the dominant harmonic source identification, concentrated multiple harmonic sources evaluation (CMHSE) and hierarchical harmonic sources evaluation (HHSE) is described in detail in order to show the completed work processes of the proposed framework. Finally, the performance of the proposed method is verified based on the real data measured from different realistic urban power grids in China. The proposed method can effectively evaluate harmonic contributions in distribution systems and in turn provide a basis for harmonic mitigation measures. [ABSTRACT FROM AUTHOR]

The main objective of this study is to quantify the groundwater contamination risk of Songhua River Basin by applying a novel approach of integrating public datasets, web services and numerical modelling techniques. To our knowledge, this study is the first to establish groundwater risk maps for the entire Songhua River Basin, one of the largest and most contamination-endangered river basins in China. Index-based groundwater risk maps were created with GIS tools at a spatial resolution of 30 arc sec by combining the results of groundwater vulnerability and hazard assessment. Groundwater vulnerability was evaluated using the DRASTIC index method based on public datasets at the highest available resolution in combination with numerical groundwater modelling. As a novel approach to overcome data scarcity at large scales, a web mapping service based data query was applied to obtain an inventory for potential hazardous sites within the basin. The groundwater risk assessment demonstrated that < 1% of Songhua River Basin is at high or very high contamination risk. These areas were mainly located in the vast plain areas with hotspots particularly in the Changchun metropolitan area. Moreover, groundwater levels and pollution point sources were found to play a significantly larger impact in assessing these areas than originally assumed by the index scheme. Moderate contamination risk was assigned to 27% of the aquifers, predominantly associated with less densely populated agricultural areas. However, the majority of aquifer area in the sparsely populated mountain ranges displayed low groundwater contamination risk. Sensitivity analysis demonstrated that this novel method is valid for regional assessments of groundwater contamination risk. Despite limitations in resolution and input data consistency, the obtained groundwater contamination risk maps will be beneficial for regional and local decision-making processes with regard to groundwater protection measures, particularly if other data availability is limited. [ABSTRACT FROM AUTHOR]

Analyzing the effect of circular-agriculture (CA) measures could be helpful to promote its scientific development. Previous research has focused on technological measures and their effects on the agricultural sector. However, economic measures can also promote the development of CA, and due to their correlation with socio-economic sectors, CA measures can impose effects on non-agricultural sectors and on the whole socioeconomic system. In this research, a computable general equilibrium (CGE) model was established to comprehensively reveal the effects of CA measures. In this model, measure simulation and environmental blocks were extended. The production tax was adopted as the economic measure for adjusting the development of CA. Both environmental and socioeconomic effects have been explored. Hebei Province in China was adopted as the study case. Three kinds of production tax adjustment scenarios were considered: a promotion-measure scenario (decreasing the production tax for CA sectors), an inhibition-measure scenario (increasing the production tax for traditional-agriculture sectors), and a hybrid-measure scenario (implementing the promotion- and inhibition-measures simultaneously). The results showed that all three scenarios could promote the development of CA. The inhibition and hybrid measures had positive effects on GDP, and all the scenarios could decrease the intensities of CO2, COD and NH3–N emissions and water resource consumption. In addition, higher measure intensity could bring more significant effects. • Economic measures can promote the development of circular agriculture (CA). • CA economic measure can improve the cleanliness of economic development. • Higher measure intensity can bring more significant effects. [ABSTRACT FROM AUTHOR]

Strategies based on virtual water have become a controversial measure to alleviate pressure on the water resource in regions with scarce water. Advocates of this approach highlight its potentially low cost and high efficiency, whereas opponents criticize its over-simplification and neglect of important factors other than water. Detailed analysis of the strategy's effects on water use and socioeconomic development is essential to fully understand the strengths and weaknesses of the strategy, and to support its reasonable and scientific implementation. In the present study, we defined three virtual water strategy scenarios (i.e., reduce agricultural production, increase agricultural imports, and reduce production and increase imports simultaneously) and developed a computable general equilibrium model to simulate the effects of the scenarios. We chose China's Bohai Bay area, a rapidly developing region with scarce water, for a case study. We found that the virtual water strategy was a double-edged sword: it improved water conservation (water use decreased by 3.6%, 6.9%, and 3.2% under the three scenarios, respectively), but had negative effects on economic development, employment, and economic welfare. The scenario that only increased agricultural imports had the greatest negative impact on socioeconomic development, whereas the scenario that simultaneously decreased production and increased imports most effectively balanced the economic development and water conservation requirements. • The virtual water strategy (VWS) exerts negative effects on economic systems. • VWS produces tradeoffs between water conservation and economic development. • The dual-policy strategy could achieve a better tradeoff. [ABSTRACT FROM AUTHOR]

Abstract: In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix × aureo-pendula CL ‘J1011’) of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25mgL−1 medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25mgL−1 medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71mg d−1pot−1 for the duration of Day 5-8 and 0.59mg d−1pot−1 for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments—willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate—led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River. [Copyright &y& Elsevier]

This study aimed to assess the trends of healthy aging and investigate its determinants in the middle-aged population. This was a longitudinal study. The sample comprised 3043 participants aged 45–59 years from the China Longitudinal Study of Health and Retirement 2011–2018. We plotted the prevalence across four waves and used ordered logistic models to investigate the determinants of cumulative times of healthy aging. We enrolled 3043 middle-aged people in our study. The prevalence of healthy aging is 28.2% at baseline but subsequently decreased to 19.72% at wave 4. Active socializing consistently ranked the lowest among the five dimensions. Participants with older age (odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.94–0.97), low monthly income (OR = 0.82, 95% CI: 0.69–0.97) or lived in urban (OR = 0.81, 95% CI: 0.70–0.94) were less likely to have per time increase in healthy aging. Participants with more than primary school degree (OR = 1.79, 95% CI: 1.31–2.46), high life satisfaction (OR = 2.38, 95% CI: 1.86–3.06), and good self-report health (OR = 1.97, 95% CI: 1.66–2.34) were more likely to have healthy aging. The number of middle-aged individuals in China who achieved healthy aging is declining and eventually less than one in five, which was far from ideal. Particular attention should be paid to older, women, urban dwellers, individuals with low income, low life satisfaction or poor self-report health. It is urgent to develop public health policies to improve the health and well-being of the middle-aged population. [ABSTRACT FROM AUTHOR]

Carbon taxation has long been proposed to mitigate carbon emissions. Carbon tax rate determination and tax revenue recycling are two key steps to achieve a double dividend under carbon taxation. However, few research has sought to optimize the allocation proportion of tax revenue to various categories of taxpayers (households, enterprises, sectors, etc.), or to optimize the two steps synchronously based on nonlinear optimization methods. In this study, a computable general equilibrium model was established to explore the influence of carbon tax rate and tax revenue recycling shares on the economy and on carbon emissions. Meanwhile, a nonlinear optimization model was proposed, for optimizing both steps of carbon taxation synchronously, as well as for promoting GDP and CO 2 emission reduction. The Bohai Bay area, a typical area with enormous carbon emissions in China, was adopted as the study case for this research. The results showed that the optimized taxation scheme could lead to lower carbon emissions and greater economic growth, i.e., a strong double dividend was obtained. The optimized taxation scheme could lead to both cleaner air and cleaner energy and industrial structures while still promoting economic growth. • CGE model is used for effect analysis under different taxation schemes. • Carbon tax rate and revenue recycling are optimized synchronously. • Lower CO 2 emissions can be achieved without economic decline. [ABSTRACT FROM AUTHOR]

• δ18O carb and δ13C alk records from a >5,000 m-thick sequence in the Qaidam Basin. • Regional moisture fluctuations over the Cenozoic inferred. • Linkage of moisture changes to global climate depends on the chosen chronology. The Cenozoic history of aridification in the Asian interior is thought to be intimately linked to uplift of the Tibetan Plateau and long-term global cooling. How fluctuating climatic conditions influenced regional moisture levels during the Cenozoic remains largely unknown. To infer moisture changes, we present oxygen isotope values of carbonates (δ18O carb) and carbon isotope values of long-chain n -alkanes (δ13C alk) from a continuous geological section in the Qaidam Basin, northwestern China. The section spans most of the Cenozoic Era, from ~52 to 5 million years ago (Ma), based on conventional chronology, whereas recently a drastically revised chronology has placed its basal age at ~26 Ma. The association of moisture changes with global climate largely depends on the chosen chronology. With the revised chronology, our records are inconsistent with existing moisture records from the Asian interior and do not show clear association with global climatic conditions. However, with the conventional chronology, our δ18O carb record shows a long-term aridification trend over the Cenozoic, whereas the δ13C alk suggests reduced moisture levels during the Oligocene. Both records consistently show enhanced aridity, notably during the Oligocene, ~20–17 Ma and after ~13 Ma, which largely corresponded to relatively cool global periods. Our records thus suggest that global climatic conditions during the Cenozoic exerted more influence on the moisture levels in the Asian interior than previously thought, if the conventional chronology is correct. Our study also highlights the importance of constructing a reliable chronology in order to make an association of Cenozoic terrestrial records with global climate. [ABSTRACT FROM AUTHOR]

• Harmonic couplings of home appliances between supply voltages and currents are strong. • Harmonics of home appliance are affected by supply voltage fluctuation and distortion. • Various behavioral factors are considered to improve the appliance random usage model. • Bottom-up approach can consider the appliance diversity and upgrading replacement. With expansion of the urban population, the power consumed by Chinese residential load is increasing rapidly. At the same time, power-electronic devices are widely adopted in home appliances, injecting a great amount of harmonics into the power system, which makes the harmonic problem in residential areas more serious than ever before. In this paper, a bottom-up approach is proposed to evaluate the harmonics of residential energy use. Firstly, a harmonic coupled model is proposed to calculate the harmonics generated by individual nonlinear home appliance. The model directly exhibits the couplings between different order harmonic voltages and currents. Secondly, based on the Markov chain Monte Carlo method, a random usage model is established to determine the usage pattern of home appliances. Various behavioral factors that affect the domestic use of energy in China are considered, and corresponding correction factors are proposed to improve the model accuracy. Thirdly, based on the proposed electrical and random usage models, a bottom-up approach is used to evaluate the harmonics and power of large-scale residential loads. Simulation results are compared with field measurements to verify the accuracy and validity of the proposed method. Furthermore, the proposed methodologies are applied to predict the harmonic generation and power consumption of some rapidly developing harmonic sources such as electric vehicles. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The water and nitrogen (N) managements play a vital role in hybrid rice production aimed at high yield, high nitrogen use efficiency (NUE), and water-saving irrigation. In order to optimize N application and understand how the different combinations of water and N management affect yield and the relative physiological parameters, we designed three irrigation regimes, standing irrigation (W1), alternation irrigation (W2), and dry cultivation (W3), combined with different N application managements at 180kgha−1 of total N condition in our study. The relationship between yield or NUE and ammonia assimilation enzyme activities, photosynthetic rate and root activity were respectively investigated. Our data revealed that there were obvious interacting effects of irrigation regime and N application strategies on grain yield and NUE as well. Our correlation analysis revealed that the grain yield or NUE was significantly related to ammonium assimilation enzyme activities, photosynthetic rate, and root activity, respectively, at several rice growth stages. Our correlation analysis also revealed that the grain yield was significantly related to the N uptake and utilization, and that the root activity was significantly related to the ammonium assimilation enzymes and photosynthetic rate. Further more, we found that the ammonium assimilation enzyme activities and the photosynthetic rate in flag leaves, or root activity at heading stage was able to be used as indicators for grain yield, total N accumulation, and NUE as well. These results suggest that the N application strategy should be adjusted according to different irrigation regimes in order to obtain the highest yield and the best NUE. Under standing irrigation, on the basis of 40–60% base-tiller N fertilizer, panicle N-fertilizer should account for 40–60% applied equally at 4th and 2nd leaves emerged or 3rd and 1st leaves emerged from the top. Under alternation irrigation, the N application ratio should be split into 30% base, 30% tillering, and 40% panicle fertilizer with the last being applied equally at 4th and 2nd leaves emerged from the top. Under dry cultivation, however, panicle N-fertilizer should account for 20–40% applied equally at 5th and 3rd leaves emerged from the top. [Copyright &y& Elsevier]

Lumnitzera littorea (Jack) Voigt is one of the most endangered mangrove species in China. Previous studies have showed the impact of chilling stress on L. littorea and the repsonses at physiological and biochemical levels, but few attentions have been paid at molecular level. In this study, we conducted genome-wide investigation of transcriptional and post-transcriptional dynamics in L. littorea in response to chilling stress (8 °C day/5 °C night). In the seedlings of L. littorea , chilling sensing and signal transducing, photosystem II regeneration and peroxidase-mediated reactive oxygen species (ROS) scavenging were substantially enhanced to combat the adverse impact induced by chilling exposure. We further revealed that alternative polyadenylation (APA) events participated in chilling stress-responsive processes, including energy metabolism and steroid biosynthesis. Furthermore, APA-mediated miRNA regulations downregulated the expression of the genes involved in fatty acid biosynthesis and elongation, and protein phosphorylation, reflecting the important role of post-transcriptional regulation in modulating chilling tolerance in L. littorea. Our findings present a molecular view to the adaptive characteristics of L. littorea and shed light on the conservation genomic approaches of endangered mangrove species. • Chilling stress caused damage to cell membrane and photosynthesis of L. littorea. • L. littorea coped with cold stress at transcriptional and post-transcriptional level. • Photosystem II regeneration and ROS scavenging were enhanced against oxidative damage. • APA acts a fine-tuning role in regulating stress-responsive gene expression. [ABSTRACT FROM AUTHOR]

Epidemiologic evidence on metal mixtures and non-alcoholic fatty liver disease (NAFLD) is limited. We aimed to assess the relationship between multiple metal co-exposure and NAFLD among male adults in Northern China. We conducted a cohort-based case-control study with 648 NAFLD and 648 non-NAFLD males. Seven metal concentrations (calcium, copper, iron, magnesium, manganese, selenium, and zinc) were determined in the blood. We used logistic regression and restricted cubic splines (RCS) to estimate the associations between the single metal and NAFLD. The impact of metal mixtures was quantified by the environmental risk score (ERS) in the adaptive elastic-net regression, and the association with NAFLD was estimated by logistic regression. Age-adjusted RCS showed linear relationships between blood calcium, selenium, and NAFLD. Blood copper, iron, magnesium, and manganese were non-linearly associated with NAFLD. Single metal analysis observed significant relationships between calcium, copper, manganese, and NAFLD, with the adjusted odds ratio (95% confidence interval) for quartile 1 vs. quartile 4 of 1.99 (1.30, 3.05), 2.36 (1.52, 3.64), and 1.77 (1.22, 2.55), respectively. However, metal mixtures analysis revealed one squared term (copper [β = −0.146]) and five metal-metal interactions (calcium × copper [β = 0.200], copper × magnesium [β = 0.188], copper × selenium [β = 0.188], iron × magnesium [β = 0.143], magnesium × selenium [β = −0.297]) except the three main effects. Higher ERS indicated a higher risk for NAFLD when exposed to metal mixtures, with an adjusted odds ratio = 6.50 (95% confidence interval: 4.36–9.69) for quartile 4 vs. quartile 1. Mediation analysis suggested that 11.66% of the effect of ERS on NAFLD was suppressed by fasting blood glucose. Our results show that exposure to metal mixtures is associated with a higher risk for NAFLD than the single metal. Interactions between metals suggest the importance of balancing the various metals for health benefits. Prospective cohorts and mechanism studies need to confirm the findings. [Display omitted] •Lower blood Ca, Cu, and Mn may be potential risk factors for NAFLD in non-occupational exposed males. •Exposure to metal mixtures is associated with a significantly higher risk for NAFLD than a single metal. •Interactions between metals suggest the importance of balancing the various metals for NAFLD prevention. [ABSTRACT FROM AUTHOR]

Abstract: The bioaccessibility and human health risks of As and heavy metals (Cu, Pb, Zn, Ni, Co, Cr, Cd and Mn) in total suspended particulates (TSP) and fine particulate matter (PM2.5) in Nanjing, China were investigated. The average mass concentration ratios of PM2.5 to TSP were 0.61 for Gulou sampling site and 0.50 for Pukou sampling site, respectively. Zn, Pb, Mn and Cu were the most abundant elements among the studied metal(loid)s in both TSP and PM2.5. The results of a simple bioaccessibility extraction test of the studied metal(loid)s varied among elements, with Cd, Zn, Mn, Pb and As showing the higher bioaccessibility. The carcinogenic risks of As, Cd, Co, Cr and Ni in both TSP and PM2.5 via dermal contact and inhalation exposure were within the acceptable level (<1 × 10−4) for both children and adults, but there was potential carcinogenic risk posed by Pb via ingestion to children and adults. The hazard index values for all of the studied elements suggested no non-carcinogenic health risks via ingestion and dermal contact, but a potential non-carcinogenic health risk via inhalation to adults. Values of hazard quotient and hazard index indicated the non-carcinogenic risks from the studied metal(loid)s to children via ingestion, dermal contact and inhalation pathways in Nanjing given the present air quality. [Copyright &y& Elsevier]

Abstract: Suzhou is located at the lower reaches of the Yangtze River in southeastern Jiangsu, China. It is part of the Su-Xi-Chang area including Suzhou, Wuxi and Changzhou. As one of the most developed areas in China, this region has suffered from severe land subsidence caused by extensive groundwater exploitation since 1980s. The land subsidence was controlled by prohibition of groundwater exploration in the past several years. However, the surface water pollution prompted a new task of how to sustainably utilize the groundwater resource, especially to satisfy the emergency demands of water supply. In this paper, we took Suzhou as a representative case to discuss how to develop groundwater resources while controlling the land subsidence. The relationship between the deformation and the groundwater level was analyzed, with focus on the deformation features after the period of groundwater exploitation ban. The results confirmed the conclusion by Shi et al. (2007, 2008a): even in the period of rising groundwater level, same units may manifest different deformation characteristics, such as elasticity, elasto-plasticity, and visco-elasto-plasticity, at different locations of the cone of depression. A land subsidence model that couples a 3-D groundwater model and a 1-D deformation model was developed to simulate the groundwater level and deformation. A high-resolution local grid (child model) for Suzhou was built based on the regional land subsidence model of Su-Xi-Chang area by Wu et al. (2009). The model was used for a number of predictive scenarios up to the year of 2012 to examine how to develop sustainable use of groundwater resources under the conditions of land subsidence control. Our results indicated that about 3.08×107 m3/a groundwater could be provided as emergency and standby water source while meeting the land subsidence control target of 10mm/a. [Copyright &y& Elsevier]

As both a toxic and essential trace element in humans, limited research focuses on the association between blood manganese (Mn) and nonalcoholic fatty liver disease (NAFLD). We aimed to assess blood Mn concentration and its relationship with NAFLD among adults in Northern China. We conducted a cohort-based case-control study among 1816 patients with NAFLD (970 males and 846 females) and 1111 healthy controls (598 males and 513 females). We used the restricted cubic splines method to investigate the potential non-linear relationship and logistic regression models to analyze the association between blood Mn and NAFLD. The median (p 25 , p 75) of blood Mn concentration in males was 10.08 (8.42,11.98) μg/L, higher than that in females [9.79 (8.01,12.04)] μg/L, P = 0.011. Compared with the tertile 1 group of Mn in males, the odds ratio (95 % confidence interval) of NAFLD for tertile 2 and tertile 3 group was 0.82 (0.61,1.10) and 0.64 (0.47,0.87), respectively. The reverse correlation was consistent in patients with different fibrosis severity determined by fibrosis-4 score. The protective association was more evident in those with triglycerides ≥1.7 mmol/L [odds ratio (95 % confidence interval) of tertile 3 vs. tertile 1: 0.40 (0.22,0.75)]. We found a non-significant U-shaped relationship between Mn and NAFLD in women. There may exist sex differences for the association between blood Mn and NAFLD. Higher blood Mn may be a potential protective factor for NAFLD in males. The subjects with TG ≥ 1.7 mmol/L would benefit more from higher blood Mn levels. [Display omitted] •Blood manganese levels were sex-specific associated with NAFLD in Chinese adults. •Higher blood manganese correlated with lower NAFLD risk in males. •Triglycerides may modify the association between blood manganese and NAFLD in males. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) in wastewater treatment plant (WWTP) effluent threats aquatic environment and challenges engineered aquatic systems. In order to predict its environmental risk and guide the selection of suitable strategy and technology, understanding the removal efficiency and the fate of DOM along the treatment is helpful. Herein, to qualitatively and quantitatively estimate the composition of DOM in a full-scale WWTP in northern China, a combined approach of chromatography and spectroscopy was employed, and the contribution of size-dependent substructure to the global feature of DOM was discussed simultaneously. The results suggest that the WWTP could remove the free proteins of low molecular size by physical treatment with removal ratios of 46.4% and 41.0% for tyrosine and tryptophan, respectively, whereas humic-like and humic-protein complex accumulate in the effluent of treatment with a ratio of 40.6%. Biotreatment is of importance for changing the proportion of different types of DOM, especially for anaerobic tank and the anoxic tank, which results in the increase of humification. Size exclusive chromatography (SEC) coupled with multi emission maps identifies six DOM substructures. Two protein-like DOM were removed by the WWTP, except the composition with the molecular weight ranging from 0.75 to 0.25 kDa, whereas humic-like DOM with whole size range accumulated to varying extent. The standard deviation analysis states that the structure variation of bulk DOM in the WWTP is primarily contributed by the decrease of small-sized proteins and the increase of humic-like DOM. This study presents insight into the fate and behavior of DOM components during the full-scale WWTP treatment and provides guidelines for altering DOM-treating technologies. Besides, innovative strategies suggest using DOM as a resource based on the critical review of previous research. [ABSTRACT FROM AUTHOR]