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The influence of cascade reservoirs construction on labile phosphorus (P) is an important scientific problem in the Lancang River. The concentration of labile P in cascade deep-water reservoirs were determined, and the influence of cascade reservoirs construction on the DGT-labile P was analyzed. The construction of cascade reservoirs led to significant differences in concentrations of DGT-labile P, which in the upstream of Xiaowan (XW) Reservoir were differences from that in the downstream Nuozhadu (NZD) Reservoir. The P diffusion fluxes in XW Reservoir were − 8.59–250.50 ng·cm− 2·d− 1, and that in NZD Reservoir were 3.82–24.80 ng·cm− 2·d− 1. The P pollution of XW Reservoir was higher, highlighting the importance of controlling P pollution of XW Reservoir. The construction of cascade reservoirs had made the release of DGT-labile P more dependent on the reductive dissolution of Mn oxides. The early diagenesis transformed bio-availability P (BAP) remobilization into DGT-labile P that made the increase of DGT-labile P/BAP with depth. However, the DGT-labile P/BAP of upstream XW Reservoir was 7.8 times larger than that of downstream NZD Reservoir, which indicated that the construction of cascade reservoirs weakened the remobilization of P in sediment.

Coupled nitrogen and oxygen isotopes of nitrate have proven useful in identifying nitrate sources and transformation in rivers. However, isotopic fractionation and low-resolution monitoring limit the accurate estimation of nitrate dynamics. In the present study, the spatio-temporal variations of nitrate isotopes (N-15 and O-18) and hydrochemical compositions (NO3- and Cl-) of river water were examined to understand nitrate sources in the Xijiang River, China. High-frequency sampling campaigns and isotopic analysis were performed at the mouth of the Xijiang River to capture temporal nitrate variabilities. The overall values of delta N-15-NO3- and delta O-18-NO3- ranged from +4.4% to +14.1% and from -0.3% to +6.8%, respectively. The results of nitrate isotopes indicated that NO3- mainly originated from soil organic nitrogen (SON), chemical fertilizer (CF), and manure and sewage wastes (MS whereas approximately 58% of nitrate was derived from anthropogenic inputs (M&S and CF) in the dry season. The nitrate flux was 2.08 x 10(5) tons N yr(-1) during one hydrologic year between 2013 and 2014, with 86% occurring in the wet season. Long-term fluctuations in nitrate flux indicated that nitrate export increased significantly over the past 35 years, and was significantly correlated with nitrate concentrations. The seasonal pattern of nitrate dynamics indicated the mixing of nitrified NO3- and denitrified NO3- between surface flow and groundwater flow under different hydrological conditions. Overall, the present study quantitatively evaluates the spatio-temporal variations in nitrate sources in a subtropical watershed, and the high-frequency monitoring gives a better estimate of nitrate exports and proportional contributions of nitrate sources.

Although numerous studies focused on nitrate source, transformation and transport of river water in karst area have been reported, it's still unclear in understanding nitrate main source and transformation in karst groundwater system and how nitrate transport from soil to water during rainfall events in karst critical zone. In order to explore the response and transport of nitrate in karst groundwater to rainfall events, different depths of well water before, during and after rainfall event were sampled, and hillslope runoff, surface runoff of different land-use types during rainfall event were sampled synchronously at a typical karst agricultural catchment in Southwest China. Results showed that fluctuations of EC, pH and DO in deep borehole well (W1) and artesian well (W2) were small, on the contrary, variations of EC and DO in shallow well (W3) were large during sampling period. The nitrate concentrations and isotopic values indicated that nitrate in karst groundwater mainly originated from chemical fertilizer (CF), and influenced by denitrification process. High intensity of denitrification was observed in deep groundwater (87%) and artesian well water (almost 100%). Extremely high dual nitrate isotope values up to 46.8 ± 1.5‰ and 24.7 ± 0.5‰ were found in the deep artesian well. The small variation of water chemistry (EC, DO and pH), nitrate concentration and dual nitrate isotope values in deep wells during sampling period suggested that newly supplied nitrogen in deep groundwater during rainfall events also comes from deep groundwater. Low nitrogen concentrations in hillslope subsurface flow and surface runoff suggests that nitrogen transport process leading to increase of water nitrogen content mainly occur in depression. Nitrogen in depression soil is mainly transported to groundwater through fissures, fractures and conduits, rather than through vertical migration processes in the soil during rainfall events.

China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area, indicating a response to different levels of urbanization. Measurements of nitrate dual isotopes suggest that volatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China.

To explore the coupled effect of temperature T and strain rate $$\dot{\varepsilon }$$ on the deformation features of AZ31 Mg alloy, mechanical behaviors and microstructural evolutions as well as surface deformation and damage features were systematically examined under uniaxial tension at T spanning from 298 to 523 K and $$\dot{\varepsilon }$$ from 10−4 to 10−2 s−1. The increase in T or the decrease in $$\dot{\varepsilon }$$ leads to the marked decrease in flow stress, the appearance of a stress quasi-plateau after an initially rapid strain hardening, and even to the occurrence of successive strain softening. Correspondingly, the plastic deformation modes of AZ31 Mg alloy transform from the predominant twinning and a limited amount of dislocation slip into the enhanced non-basal slip and the dynamic recrystallization (DRX) together with the weakened twinning. Meanwhile, the cracking modes also change from along grain boundaries (GBs) and at twin boundaries (TBs) or the end of twins into nearby GBs where the DRX has occurred. The appearance of a stress quasi-plateau, the formation of large-sized cracks nearby GBs, and the occurrence of continuous strain softening, are intimately related to the enhancement of the non-basal slip and the DRX.

Understanding where nitrate is mobilized from and under what conditions is required to reduce nitrate loss and protect water quality. Low frequency sampling may inadequately capture hydrological and biogeochemical processes that will influence nitrate behavior. We used high-frequency isotope sampling and in-situ nitrate sensing to explore nitrate export and transformation in a karst critical zone. Nitrate was mobilised during light rainfall, and transferred from soil layers to the karst matrix, where some nitrate was retained and denitrified. Nitrate isotopic composition changed rapidly during the rising limb of events and slowly during the falling limb. The main nitrate source was synthetic fertiliser (up to 80% during event flow), transported by conduit flow following high rainfall events, and this contribution increased significantly as discharge increased. Soil organic nitrogen contribution remained constant indicating at baseflow this is the primary source. Isotope source appointment of nitrate export revealed that synthetic fertilizer accounted for more than half of the total nitrate export, which is double that of the secondary source (soil organic nitrogen), providing valuable information to inform catchment management to reduce nitrate losses and fluvial loading. Careful land management and fertilizer use are necessary to avoid nitrate pollution in the karst agroecosystem, for example by timing fertilizer applications to allow for plant uptake of nitrate before rainfall can flush it from the soils into the karst and ultimately into catchment drainage.

Dissolved organic carbon (DOC) plays a key role among the earth-surficial ecosystem, particularly in the climate change, but very few researches focused on the rainwater DOC in karst agricultural region (vulnerable agro-ecosystem). To identify the concentrations, seasonal variations, controlling factors, deposition fluxes, and potential sources of DOC in rainwater, 85 rainwater samples were collected at the Houzhai catchment, a representative karst agriculture-intensive region in Southwest China, from June 2016 to May 2017. The concentrations and deposition flux of DOC were 0.63 mg C L−1 (volume-weighted mean) and 0.67 g C m−2 yr−1. These values were lower than the Asian average value, reflecting a low level of contaminated atmospheric organic carbon in the studied area. Seasonally, low DOC concentrations were often accompanied by high deposition flux during the rainy season (heavy rainfall), suggesting that the amount of rainfall is the critical factor controlling the rainwater DOC. Moreover, long-distance migration and anthropogenic emissions were also the non-negligible impact factors. The source identification showed that both agriculture-related volatilization and fossil fuel burning (mainly coal-combustion) were the primary sources of rainwater DOC according to the correlation analysis with the major ions (typical indicators), while the contribution of other origins (e.g., plant-released, biomass burning, and windblown dust) were limited. This study clearly explores the karst-agricultural wet deposition process of DOC that would strongly benefit the study of the global carbon biogeochemical cycle.

Rainwater chemistry plays an important role in the earth-surficial ecosystem, but studies on rainwater chemical composition of karst agro-ecosystem are rare. To explore the rainwater alkalization and the provenance of components responsible for neutralization, two-years chemical monitoring of rainwater was carried out in a karst agricultural catchment in Southwest China. The main findings suggest that SO42-, NO3-, Ca2+, and NH4+ are the principal ions. All the ionic contents show distinctly seasonal variation (highest in winter) in response to variations in seasonal precipitation because the rain-scour process can efficiently remove atmospheric materials. Source identification indicates that Cl- and Na+ are mainly derived from marine input whereas SO42- and NO3- are controlled by anthropogenic emission, in particular, fixed emission sources. The source of NH4+ is attributed to intense agricultural production, while Ca2+ and Mg2+ are mainly derived from calcite dissolution. The rainwater alkalization caused by the seasonal acid neutralization (via basic components, Ca2+ and NH4+) is beneficial to crop growth but also reflect agricultural overfertilization. Sulfur controlled the total wet acid deposition (68%-94%) and could be a potential agent of weathering.

Nitrogen (N) deposition plays a key role in ecosystem function as one of the major N sources for natural vegetation, particularly in karst agricultural areas with thin soil cover, which drive the karst N fate via rainwater. To understand the seasonal and spatial variation in nitrogen deposition and to identify the major sources of nitrate in wet deposition in a karst agricultural area (Houzhai Catchment) in southwestern China, two sites with different land use were selected to assess wet and dry deposition for one year. Houzhai village (HZV) is an area highly influenced by agriculture, whereas Muzhu reservoir (MZR) is a more pristine environment with less anthropogenic influence. Nitrogenous species and dual nitrate isotopes were analyzed. The results showed that agriculture-derived NH4+ was the major contributor of annual total wet N deposition (>55 %). The contribution of NH4+ to wet N deposition was 1.63 times higher than that of NO3− and dissolved organic nitrogen (DON). The annual nitrogen deposition in this study was approximately twice as much as the average wet N deposition over China, while lower dry N deposition relative to other Chinese monitoring sites was observed. The δ15N-NO3− showed a seasonal trend of negative summer values and positive winter values, which were primarily controlled by the variations in NOx emission sources. Seasonal variation in δ18O-NO3− was mainly controlled by NOx oxidation pathways and showed a similar trend to δ15N-NO3−. The contributions from four endmembers (coal combustion, vehicle exhaust, biomass burning, and soil emission) were calculated using a stable isotope mixing model. Contributions show a clear seasonal variation (except vehicle exhaust), with the four sources accounting for 20.0 %, 25.6 %, 22.9 % and 31.5 % respectively (annual mean probability estimate, AMPE) at HZV, and 19.0 %, 27.8 %, 23.2 % and 30.0 % (AMPE) at MZR. Isotopic evidence determined agricultural soil emission is a major contributor to rainwater during the summer growing season, which can significantly impact the agricultural ecosystems.

High discharge associated with rainfall events causes rapid transport of nutrients to drainage systems in karst terrain. The objective of this study was to understand nitrate dynamics and transport mechanisms during rainfall events in a typical mixed land-use karst catchment in Southwest China. High frequency (hourly) water sampling, discharge and hydrochemistry sensor data at a 15-minute interval were collected from a karst agricultural surface river over four rainfall events, spanning 40 days at the commencement of the wet season. The results showed that high [NH4+–N] (up to 3.12 mg L−1) and [PO43−– P] (up to 1037 μg L−1) were observed in the first rainfall event of the wet season, after a long preceding dry period. Increased [NO3−–N] also occurred during the high discharge associated with early event flows, but the highest [NO3−–N] concentrations (up to 14.9 mg L−1) were observed later in the season during the highest discharge events. All minima for dual nitrate isotopes were found during high discharge conditions and increased through the event time series. This indicates that nitrogen accumulated in the catchment prior to the commencement of the wet season and was flushed by the early rainfall events into the drainage system. Analysis of [NO3−–N], δ15N and δ18O-NO3− values indicate that denitrification, not assimilation, resulted in the high nitrate isotope values before and after rainfall events. According to source apportionment, chemical fertilizer, soil organic nitrogen, and manure and sewage, which varied with discharge, were the main sources of nitrate during rainfall events. The high proportion of nitrate from soil organic nitrogen suggested that soil loss from peak clusters and lowland farmland during heavy rainfall events should be paid more attention in karst area.

Nitrogenous species, particularly nitrate, are some of the most significant contaminants in freshwater rivers and lakes in China, posing a significant threat to human and ecosystem health. To identify the major nitrate sources and transformation processes in a subtropical karst lake (Hongfeng, HF) in Southwest China, two sampling campaigns involving three lake profiles were conducted during the impoundment period (April) and flood period (August). Hydro-chemistry parameters, concentration of nitrogenous species, and dual isotopes of nitrate were analyzed. Nitrate was the major nitrogenous species in HF lake with higher proportion in April than August. The concentrations of NH4+, NO2- and dissolved organic nitrogen were below the detection limit in April, while NH4+ increased with depth in August, which may be a result of mineralization. Nitrification was detected during the impoundment period and from the surface to a depth of 10 m during the flood period. Denitrification was detected in the lake bottom waters during the flood period with isotopic fractionation of -10.7‰ for δ15N-NO3- and -4.7‰ for δ18O-NO3-. The Rayleigh distillation demonstrated denitrification showed spatial variation (53% and 89% of nitrate in the southern and northern region of the lake, respectively). The Bayesian modelling results suggest that organic nitrogen degradation and sediment make the largest contributions to nitrate (51% and 38% in April and 33% and 24% in August, respectively) to the lake. Tributaries contributed more nitrate in August (37%) than in April (10%). The results highlight that modified endogenous nitrogen contributed a high proportion of nitrate sources within the lake system during the two periods.

The control and regulation of SOx emissions have become a global urgent problem for the environment protection. In the field of ocean and marine engineering, The International Maritime Organization (IMO) has formally passed the amendment of MARPOL 73/78 Annex VI in 2008 that clarified the deadline of requirements on SOx emissions limit. A limitation of 3.5 %mm is strictly requested during 2012 to 2020. Hence the SOx emissions of marine diesel engines faces unprecedented challenges while effective control and regulation systems on the SOx emissions reduction are scarce in the existing ships. To meet the IMO's requirements, this paper has presented a novel seawater exhaust gas cleaning (EGC) system for the SOx emissions reduction of marine diesel engines. The post-combustion desulfurization technology was employed in the EGC system. The carbon ion and hydrogen ion contained in the seawater have been introduced into the EGC system to participant the reaction of desulfurization. The seawater EGC system has already been established in a real ship. Experiments have been carried out with the established seawater EGC system to comparatively analyze SOX emissions characteristics when burning different oil types, including heavy oil and light oil. The experiment results show that the newly established seawater EGC system can achieve satisfactory performance with a desulfurization efficiency of 88%. More important, the standard of the SOX emission limitation set by IMO has been met by using the proposed EGC system.

The traditional way to study Sources–Receptor Relationships (SRRs) of wet deposition is based on sensitivity simulation, which has weakness in dealing with the non-linear secondary formation pollutants (e.g. ozone and nitrate). An on-line source tracking method has been developed in the Nested Air Quality Prediction Modeling System (NAQPMS) coupled with cloud-process module for the first time. The new model can not only quantify the total volume of the sulfate, nitrate and ammonium wet deposition with more accuracy, but also trace these acidic species to their emitted precursors. Compared with previous studies, our result clearly shows: (1) East China and Central China, which are the two primary export regions, have 15–30% and 10% effect on wet deposition in other areas, respectively; (2) Besides the above two regions, the total acid deposition in Southwestern and Northeastern China have reached or exceeded the critical loads under their own environmental conditions.

For the large marine main propulsion diesel engine, before delivered to shipyards should be evaluated NOx emission. This paper proposed a method just by analyzing the related parameters to evaluate the emission of marine diesel engine. Based on the small bore marine main propulsion diesel engine, analyzed the variation of performance parameters, to evaluate the emission performance at the condition of different power/speed at CMCR point and electric control mode. And the analysis results show that, for the same main propulsion diesel engine, the power of CMCR point has no obvious effect on the NOx emission performance, while the electric mode has a certain effect on the NOx emission performance. Finally, shop testing ware carried out to measure the NOx emission at the above condition, and the testing results approved the analysis results, and the parameter analysis method can be used in the practice.

Agricultural land in karst systems can pollute water courses, with polluted waters travelling quickly to and through the sub-surface. Understanding how rapidly nitrate moves within the highly-transmissive karst critical zone (from soils to aquifers) is limited by low resolution data. To understand nitrate behavior and its controls, we deployed sensor technology at five sites to generate autonomously high-resolution time series of discharge and NO3−–N, which is the major nitrogenous component, in a farmed karst catchment in Southwestern China. The [NO3−–N] time series exhibited rapid response to rainfall-induced increases in discharge and a large magnitude in [NO3−–N], from 0.72 to 16.3 mg/L across five sites. However, the magnitude of NO3−–N response at each site was varied during rainfall events (wet season) and dry season. The highest mean [NO3−–N] and normalized annual fluvial export occurred in a headwater catchment with a developed karst aquifer system. Seasonal variation in NO3−–N export occurred in response to source availability, most notable in catchments with valley agriculture: in the wet season up to 94% of nitrate was exported from the headwater catchments within two months, but at the larger catchment scale, over the 6 month wet season, only 61% of total export occurred. At the larger catchment scale, [NO3−–N] were lower due to buffering by the karstic aquifer network. From the time series we observe little decrease in [NO3−–N] as discharge decreases in the dry season, indicating the karst aquifers are chronically-polluted with nitrate through slow flow pathways.

Atmospheric wet deposition is a vital part of biogeochemical cycles in earth surface environment systems, which is not only controlled by local sources and long-range transported continental substances from natural and anthropogenic sources, but also potentially influenced by the topographical features (e.g. peak clusters and depressions in karst areas). To investigate the depression trapping effect of vertical distribution of rainwater chemical composition and evaluate the effect of trapping by depression on wet deposition flux, rainwater samples from two sites (HR, a hilltop shrubbery area, and LR, inside a depression paddy field area) of a karst agricultural depression in Southwest China, were collected during the rainy season. From these, the major ionic concentrations were measured. The results indicated a variance in pH from 4.8 to 6.4 with a volume-weighted mean (VWM) value of 5.7 at the HR, and, a range of 5.4–6.9 with a VWM of 6.0 at the LR. The VWM concentrations of ions were decreased in the order of SO42- > NH4+ > Ca2+ > NO3- > Mg2+ > K+ > Na+ > Cl− > F− at both sites, and were dominated by SO42-, NH4+, Ca2+, and NO3-, accounting for >87% of the total ions at the two sites. The result of fractional acidity (FA) and neutralization factors (NF) revealed that the relatively high pH values were the result of neutralization of the alkaline substances (NH4+ and Ca2+) rather than the scarcity of acidic materials. Source analysis of major ions showed that anions were predominantly controlled by anthropogenic emission, while cations originated from both terrestrial sources and anthropogenic activity. The vertical distribution of dominant ions (NH4+, NO3-, Ca2+, Mg2+, and SO42-) were ascribed to the relatively weak air convection movement within the depression area (specific atmospheric circulations) and the differences in human interference at two sites (LR, cultivated land; HR, luxuriant vegetation). This is further supported by the more negative rainwater δ15N–NO3- values (−8.5 to −6.0‰), in LR than that in HR (−6.2 to −3.4‰). The depression trapping effect could significantly affect the estimation of wet deposition fluxes (up to 80.6% for Ca2+ and 68.7% for NH4+), which requires consideration in future studies, e.g. N wet deposition.

Inversion of the carbon monoxide (CO) emissions over Beijing and surrounding areas in the summer of 2010 is carried on the Nested Air Quality Prediction Modeling System (NAQPMS) in coupling with an ensemble Kalman filter. CO emission is estimated through integration of observations data obtained from 25 sites in Beijing and surrounding areas of which 13 sites selected as assimilation sites are used to perform a joint adjustment of both CO concentrations and emissions with hourly surface CO observations, and 12 other sites selected to validate the inversion emission inventory. As a result, estimated CO emissions (Tg year −1 ) for Beijing, Tianjin, Tangshan and Baoding are 4.11, 3.75, 3.17 and 4.08, respectively; higher than the a priori estimates in the Regional Emission inventory in Asia Version 1.1 (REAS V1.1) by 50%, 80%, 120% and 150% respectively. Obviously, the regional CO emissions are underestimated in REAS1.1, especially over Beijing and surrounding areas. Use of the inverse emission inventory reduces the bias of CO simulation by 64% at assimilation sites and 48% at validation sites.

Carbon monoxide (CO) is of great interest as a restriction factor for pollutants related to incomplete combustions. This study attempted to evaluate CO emission in East China using the analytical Bayesian inverse method and observations at Mount Hua in springtime. The mixing ratio of CO at the receptor was calculated using 5-day source-receptor relationship (SRR) simulated by a Lagrangian Particle Dispersion Model (FLEXPART) and CO emission flux. The stability of the inversion solution was evaluated on the basis of repeated random sampling simulations. The inversion results demonstrated that there were two city cluster regions (the Beijing-Tianjin-Hebei region and the low reaches of the Yangtze River Delta) where the difference between a priori (Intercontinental Chemical Transport Experiment-Phase B, INTEX-B) and a posteriori was statistically significant and the a priori might underestimate the CO emission flux by 37 %. A correction factor (a posteriori/a priori) of 1.26 was suggested for CO emission in China in spring. The spatial distribution and magnitude of the CO emission flux were comparable to the latest regional emission inventory in Asia (REAS2.0). Nevertheless, further evaluation is still necessary in view of the larger uncertainties for both the analytical inversion and the bottom-up statistical approaches.

The purification effects of Er addition in chloride flux during smelting on microstructure, tensile properties, and corrosion resistance of as-cast AZ80D magnesium alloy were carried out. The results show that Er addition in the flux can eliminate the MgO inclusions and improve the tensile properties and corrosion resistance of the alloy. Using chloride flux mixed with 8.0 wt% Er, σ b and δ of the as-cast AZ80D magnesium alloy can be improved from 150 MPa and 2.1 % to the maximum value of 230 MPa and 4.8 %, respectively. Meanwhile, the corrosion rate decreases from 1.10 to 0.12 mg·(cm2·d)−1 in 5 wt% NaCl solution. However, with increasing Er content in chloride flux further, φ-(Al7ErMn5) and τ-(Al66.7Mg23.3Er10) phase are formed, and the morphology of γ-(Mg17Al12) phase is modified. The coarse φ-(Al7ErMn5) phase along dendrite boundaries decreases cohesion force between dendrites, which results in the worse of tensile properties.

Studying the correlations of carbonaceous aerosols (element carbon, EC, and organic carbon, OC) from open biomass burning helps to reduce uncertainties in emission inventories and provides necessary constraints for model simulations. In the present study, we measured apparent elemental carbon (ECa) and OC concentrations at the summit of Mount Tai (Mt. Tai) during intensive open crop residue burning (OCRB) episodes using a Sunset OCEC analyzer. In the fine particle mode, OC and ECa showed strong correlations (r > 0.9) with carbon monoxide (CO). Footprint analysis using the FLEXPART_WRF model indicated that OCRB in Central East China had a significant influence on ambient carbonaceous aerosol loadings at the summit of Mt. Tai. During campaign, ΔECa/ΔCO ratios of OCRB plumes were found to be 14.3 ± 1.0 ng m−3 ppbv at Mt. Tai. This ratio was twice larger than those for urban pollution in CEC, demonstrating that significant emissions of soot particles emitted from OCRB. ΔOC/ΔCO ratio of OCRB plumes was found to be 41.9 ± 2.6 ng m−3 ppbv averagely. The transport time of smoke particles was estimated using the FLEXPART_WRF tracer model by releasing particles from the ground layer inside geographical regions where large numbers of hotspots were detected by the MODIS sensor. The relationship between transport time and observed ΔECa/ΔCO and ΔOC/ΔCO ratios was fitted by an e-folding exponential function. Results showed that the loss rate of OC (normalized by CO) with transport was much quicker than that of ECa mass, and the corresponding lifetime of OC mass was estimated to be 28.0–44.2 h (1.2–1.8 days), much shorter than that 98.4–136.9 h (4.1–5.7 days) of ECa. Lifetime of ECa estimated for the OCRB events in CEC in the study was comparably lower than the values normally calculated by the transport models. Short lifetime of OC highlighted its vulnerability to cloud scavenging in the presence of water-soluble organic species from biomass combustion.

Current Nurse scheduling process has many challenges like work plan creation and working hour allocation for employees at specific planning horizon. Hospitals in most of the developing countries use manual methods to create nurse scheduling systems. With current existing manual nurse scheduling systems, most of the hospitals especially in developing countries don’t have efficient work plan allocation. Moreover, patients need nursing care throughout the day. Hence, current manual nurse scheduling approach with simple statistical functions is not efficient especially for highly populated countries. Our proposed automated nurse scheduling approach has carried out in two stages. Firstly, we propose an efficient data warehouse system based on online analytical method for hospital information system. Subsequently, Enhanced Greedy Optimization algorithm is implemented to optimize the nurse roster and compared with other optimization algorithms (Simulated Annealing and Genetic Algorithm). Experimental results (MYSQL, JAVA, OLAP) with proposed optimization algorithm outperforms compared with existing optimization solutions.

In this paper, the influence of ageing and solution treatment on the low cycle fatigue behavior of a rolled AZ80 magnesium alloy sheet was investigated at constant total strain amplitudes between 0.003 and 0.01. It was observed that fatigue life of the alloy sheet at as-rolled, ageing and solution treatment conditions can be described well by Coffin-Manson and Basquin’s equations. The fatigue parameters follow the two equations were evaluated. With increasing total strain amplitude, the fatigue life of the three conditions decreased. At the lowest total strain amplitude of 0.003, the fatigue life of the as-rolled alloy sheet was the biggest. However, at the highest total strain amplitude of 0.01, the fatigue life of solution treated alloy sheet was the biggest, and that of the ageing treated alloy sheet was the shortest.

The microstructure and tensile properties at room temperature of as-extruded Mg94.5Zn4Y1Er0.5 alloy sheet were studied. The results show that the alloy is mainly composed of equiaxial-liked α-(Mg) grains and W phase containing lots of rare earth elements (F.C.C. structure, a=0.707nm). The elongation and tensile strength of the alloy sheet in hot extruded and transverse direction are 25.5 %, 29.9 % and 247 MPa, 240 MPa, respectively. The above results manifest that the W phase stimulate the DRX during hot extrusion, reduce the preference of basal texture of magnesium alloy, markedly improve the plastically shaping capability at room temperature.

The microstructures and corrosion resistance of AZ91 and AZ91+0.5 wt.% erbium (Er) magnesium alloys were studied, respectively. The results show that the Er addition in scrap AZ91 magnesium alloy can improve the corrosion resistance, markedly. The discontinuous precipitation phase (DPP) for Mg17Al12was retarded and the amount of DPP was decreased by 41% due to the formation of Al8ErMn4phase during solidification. The amount of continuous precipitation phase (CPP) in grains was decreased by 8% because of the formation of Al7ErMn5phase during solidification.

The phase structure of ZK60-1Er magnesium alloy thermally compressed at the temperature of 450 °C and the strain rate of 1×10 −4 s −1 was determined by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). The results show that this magnesium alloy contains many new W phases (Mg 3 Zn 3 Er 2 , FCC structure) in the matrix. Those new W phases have two morphologies, either irregularly rectangular or rod morphology. Lattice constants of the two new W phases are slightly higher than those of W Phase (Mg 3 Zn 3 Y 2 ) containing rare earth element of yttrium.

A global atmospheric transport model is used to calculate lead concentrations in the atmosphere. The model performance is evaluated through comparisons with observations in Europe. The model results of lead concentrations in surface air were compared with measurements in East Asia. The detailed comparisons showed generally good agreement for recent decades, although systematic underestimation was found in China. Anthropogenic lead emissions in China are estimated from economic statistics to be 56 000 t yr −1 , which is not small considering the economic scale of China. The underestimations suggest a hidden source of lead emissions. The emissions in Japan and Korea are derived from optimization by the model. The magnitude is about 2000 t yr −1 , which is much greater than that reported by the Pollutant Release and Transfer Register in Japan and Toxics Release Inventory in Korea.

Eight chemical transport models participate in a model intercomparison study for East Asia, MICS-Asia II. This paper analyzes calculated results for particulate matter of sulfate, nitrate and ammonium through comparisons with each other and with monthly measurements at EANET (the acid deposition monitoring network in East Asia) and daily measurements at Fukue, Japan. To the EANET measurements, model ensemble means better agree with model individual results for sulfate and total ammonium, although total nitrate is consistently and considerably underestimated. To measurements at Fukue, the models show better agreement than for the EANET measurements. This is likely because Fukue is centered in many of the model domains, whereas the EANET stations are mostly in Southeast Asia and Russia. Moreover, it would be important that Fukue is in Northeast Asia, where the emission inventory is more reliable than Southeast Asia. The model-model comparisons are made in view of the total amount in the atmosphere, vertical profile, coefficient of variation in surface concentrations, and transformation changes with distance. All the models show reasonable tendencies in vertical profiles and composition ratios. However, total amounts in the atmosphere are discrepant among the models. The consistency of the total amount in the atmosphere would influence source-receptor analysis. It seems that model results would be consistent, if the models take into account the primitive processes like emission, advection/diffusion, chemical transformation and dry/wet deposition, no matter the processes are modeled simply or comprehensively. Through the comparison study, we learned that it would be difficult to find any problems from one comparison (model-observation comparison with one data or many but at one station or in a short period). Modelers tend to examine model performances only from model-observation comparisons. However, taking budget in a certain or whole model domain would be important, before the models are applied to source-receptor analysis.

Results from the Model Intercomparison Study Asia Phase II (MICS-Asia II) are presented. Nine different regional modeling groups simulated chemistry and transport of ozone (O 3 ), secondary aerosol, acid deposition, and associated precursors, using common emissions and boundary conditions derived from a global model. Four-month-long periods, representing 2 years and three seasons (i.e., March, July, and December in 2001, and March in 2002), are analyzed. New observational data, obtained under the EANET (the Acid Deposition Monitoring Network in East Asia) monitoring program, were made available for this study, and these data provide a regional database to compare with model simulations. The analysis focused around seven subject areas: O 3 and related precursors, aerosols, acid deposition, global inflow of pollutants and precursor to Asia, model sensitivities to aerosol parameterization, analysis of emission fields, and detailed analyses of individual models, each of which is presented in a companion paper in this issue of Atmospheric Environment . This overview discusses the major findings of the study, as well as information on common emissions, meteorological conditions, and observations.

Eight regional Eulerian chemical transport models (CTMs) are compared with each other and with an extensive set of observations including ground-level concentrations from EANET, ozone soundings from JMA and vertical profiles from the TRACE-P experiment to evaluate the models’ abilities in simulating O3 and relevant species (SO2, NO, NO2, HNO3 and PAN) in the troposphere of East Asia and to look for similarities and differences among model performances. Statistical analysis is conducted to help estimate the consistency and discrepancy between model simulation and observation in terms of various species, seasons, locations, as well as altitude ranges. In general, all models show a good skill of simulating SO2 for both ground level and the lower troposphere, although two of the eight models systematically overpredict SO2 concentration. The model skills for O3 vary largely with region and season. For ground-level O3, model results are best correlated with observations in July 2001. Comparing with O3 soundings measured in the afternoon reveals the best consistency among models in March 2001 and the largest disparity in O3 magnitude in July 2001, although most models produce the best correlation in July as well. In terms of the statistics for the four flights of TRACE-P experiment, most models appear to be able to accurately capture the variability in the lower troposphere. The model performances for NOx are relatively poor, with lower correlation and with almost all models tending to underpredict NOx levels, due to larger uncertainties in either emission estimates or complex chemical mechanism represented. All models exhibit larger RMSE at altitudes

To evaluate the value of urine Livin and Survivin mRNA expression in the early diagnosis of bladder cancer.Fifty-two cases of early bladder cancer and 30 cases of non-urinary system tumors were selected for the combined detection of urinary Livin and Survivin and urine cytology.Livin and Survivin in urine and urinary cytology sensitivity were 71.2% (37/52) , 67.3% (35/52), 23.1% (12/52); Specificity were 96.7% (29/30) , 93.3% (28/30) and 96.7% (29/30) respectively. Urine Survivin sensitivity, specificity compared with Livin were no significant difference (all P0.05). Urinary Livin and Survivin were more sensitive than urine cytology, and the differences were statistically significant(all P0.05).The combined urinary detection of Livin, Survivin mRNA expression is a noninvasive early diagnosis of bladder cancer with sensitivity and specificity.