Effects of tracking linkage self-management mode on the compliance of prenatal examinations and delivery modes in primiparas.

To explore the effects of tracking linkage self-management mode on the compliance of prenatal examinations and delivery modes in primiparas. A total of 270 primiparas undergoing prenatal examinations in Shijiazhuang Obstetrics and Gynecology Hospital were enrolled for prospective study between January 2021 and January 2022. They were divided into control group and observation group, 135 cases in each group. The control group was given routine management mode, while observation group was given tracking linkage self-management mode. All were intervened till discharge. The compliance (time and frequency of prenatal examinations), cognition of prenatal examinations, score of exercise of self-care agency scale, self-rating anxiety scale and self-rating depression scale, delivery modes and the occurrence of neonatal adverse outcomes were compared between the 2 groups. After intervention, total compliance rate of prenatal examinations in observation group was higher than that in control group (84.44% vs 72.59%) (P < .05). The scores of pregnancy care, genetic diseases counseling, prevention of birth defects and reasonable nutrition during pregnancy in observation group were higher than those in control group (P < .05), scores of health cognition, self-care skills, self-care responsibility and self-concept were higher than those in control group (P < .05), scores of self-rating anxiety scale and self-rating depression scale were lower than those in control group (P < .05), natural delivery rate was higher than that in control group (85.93% vs 74.81%) (P < .05), and incidence of neonatal adverse outcomes was lower than that in control group (0.74% vs 5.93%) (Fisher exact probability = 0.036). The application of tracking linkage self-management mode can significantly improve cognition to prenatal examinations, improve compliance of prenatal examinations and self-care ability, relieve anxiety and depression, increase natural delivery rate and reduce the incidence of neonatal adverse outcomes in primiparas.

Soil Water Movement and Groundwater Recharge Under Different Land Uses in a Flood-Irrigated Area.

The water shortage in agriculture area in China requires to reduce the consumption of excessive water in flood irrigation. Therefore, the dynamics of soil water regime is needed to investigate and water-saving irrigation is necessary to alleviate water shortage. This study investigated the impact of flood irrigation on soil water movement and recharge to groundwater in the Yellow River irrigation area of Yinchuan Plain, China. Combining comprehensive field observation, stable isotopic techniques and water balance simulation, we described the soil water mechanism in vadose zone covered with bare soil in 2019 and planted with maize in 2020. The soil layers affected by precipitation infiltration and evaporation were mainly 0-50 cm, while the soil influenced by irrigation was the entire profile in the mode of piston flow. The maize root took up the soil water up to the depth of 100 cm during the tasseling period. The infiltration and capillary rise in 2020 were similar with those in 2019. However, the total deep percolation was 156.5 mm in 2020 which was about 50% of that in 2019 because of the maize root water uptake. The leakage of ditch water was the major recharge resource of groundwater for the fast water table rise. Precise irrigation is required to minimize deep percolation and leakage of ditch water and reduce excessive unproductive evapotranspiration. Therefore, understanding the soil water movement and groundwater recharge is critical for agricultural water management to improve irrigation efficiency and water use efficiency in arid regions.

Sources and hydrogeochemical processes of groundwater under multiple water source recharge condition.

Ecological water replenishment (EWR) is an essential approach for improving the quantity and quality of regional water. The Chaobai River is a major river in Beijing that is replenished with water from multiple sources, including reclaimed water (RW), the South-North Water Transfer Project (SNTP), reservoir discharge (RD). The effects of multiple water source recharge (MWSR) on groundwater quality remain unclear. In this study, hydrochemical ions, isotopes (δ2H-H2O, δ18O-H2O, δ15N-NO3-, and δ18O-NO3-), mixing stable isotope analysis in R (MixSIAR), and hydrogeochemical modeling were used to quantify the contributions and impacts of different water sources on groundwater and to propose a conceptual model. The results showed that during the period before reservoir discharge, RW and SNTP accounted for 38 %-41 % and 54 % of the groundwater in their corresponding recharge areas, respectively. The groundwater in the RW recharge area contained high levels of Na+ and Cl- leading to the precipitation of halite, and was the main factor for the spatial variation in groundwater hydrochemical components. The surface water changed from Na·K - Cl·SO4 type to Ca·Mg - HCO3 type which was similar to groundwater after reservoir discharge. RD accounted for 30 % of the groundwater; however, it did not change the hydrochemical type of groundwater. Dual nitrate stable isotopes and MixSIAR demonstrated that RW was the primary source of NO3- in groundwater, contributing up to 76-89 %, and reservoir discharge effectively reduced the contribution of RW. δ15N-NO3- or δ18O-NO3- in relation to NO3-N suggests that denitrification is the main biogeochemical process of nitrogen in groundwater, whereas water recharge from the SNTP and RD reduces denitrification and dilutes NO3-. This study provides insights into the impact of anthropogenically controlled ecological water replenishment from different water sources on groundwater and guides the reasonable allocation of water resources.

[Occurrence Characteristics of Microplastics in Baiyangdian Lake Water and Sediments].

In order to explore the occurrence characteristics of microplastics in the freshwater environment of Baiyangdian Lake in China, ten overlying water samples and ten sediment samples were collected in Baiyangdian Lake of Hebei Province in October 2021, and the abundance distribution, shape, particle size, and polymer type of microplastics in the samples were identified using laboratory pretreatment, microscope observation, and laser infrared spectroscopy. The sedimentation law of microplastics at the overlying water-sediment interface was studied using the Stokes sedimentation formula, and their pollution characteristics and potential sources were analyzed. The abundances of microplastics in the overlying water and sediments in Baiyangdian Lake ranged from 474-19382 n·m-3 and 95.3-29542.5 n·kg-1, respectively, with an average value of 6255.4 n·m-3 and 11088 n·kg-1. The main polymer of the microplastics in the overlying water was polyethylene terephthalate[PET, (17.20±0.26)%], and the microplastics in the sediments were mainly chlorinated polyethylene[CPE, (46.11±1.30)%]. The sedimentation velocities of microplastics in the sedimentation zone ranged from 0.0793-111.7547 mm·s-1. The particles with larger particle size had higher sedimentation velocity and easily settled and remained in the sediments. The main sources of microplastic pollution in the study area were the discharge of textile fibers from washing wastewater and the wear and tear of ship paint, ship rubber, and building materials.

Review of Endocrine Disrupting Compounds (EDCs) in China's water environments: Implications for environmental fate, transport and health risks.

Endocrine Disrupting Compounds (EDCs) are ubiquitous in soil and water system and have become a great issue of environmental and public health concern since the 1990s. However, the occurrence and mechanism(s) of EDCs' migration and transformation at the watershed scale are poorly understood. A review of EDCs pollution in China's major watersheds (and comparison to other countries) has been carried out to better assess these issues and associated ecological risks, compiling a large amount of data. Comparing the distribution characteristics of EDCs in water environments around the world and analyzing various measures and systems for managing EDCs internationally, the significant insights of the review are: 1) There are significant spatial differences and concentration variations of EDCs in surface water and groundwater in China, yet all regions present non-negligible ecological risks. 2) The hyporheic zone, as a transitional zone of surface water and groundwater interaction, can effectively adsorb and degrade EDCs and prevent the migration of high concentrations of EDCs from surface water to groundwater. This suggests that more attention needs to be paid to the role played by critical zones in water environments, when considering the removal of EDCs in water environments. 3) In China, there is a lack of comprehensive and effective regulations to limit and reduce EDCs generated during human activities and their discharge into the water environment. 4) To prevent the deterioration of surface water and groundwater quality, the monitoring and management of EDCs in water environments should be strengthened in China. This review provides a thorough survey of scientifically valid data and recommendations for the development of policies for the management of EDCs in China's water environment.

[Spatial-temporal Variation in Water Quality and Its Response to Precipitation and Land Use in Baiyangdian Lake in the Early Stage of the Construction of Xiong'an New Area].

To assess the water quality of Baiyangdian Lake in the early stage of construction of the Xiong'an New Area, the water quality data in Baiyangdian Lake from December 2020 to November 2021 were collected from five typical monitoring stations. Using the remote-sensing interpretation of land use types, Pearson correlation analysis, comprehensive pollution index, and principal component analysis, the spatial-temporal variation characteristics of the water quality and its response to precipitation and land use structure at different spatial scales were explored in Baiyangdian Lake. The results showed that:① the water quality of Baiyangdian Lake was the best in spring and the worst in summer. Nutrient pollution was the heaviest at Nanliuzhuang, which was greatly affected by the Fuhe River. Organic pollution was the heaviest at Caiputai. ② The comprehensive pollution index of Nanliuzhuang was the highest, followed by that of Shaochedian, Guangdianzhangzhuang, Caiputai, and Quantou. The main excessive pollutant was TN, and the pollution index of 1.55 reached the level of severe pollution. The water quality of Baiyangdian Lake was significantly better than that before the construction of the Xiong'an New Area. ③ The construction land and cropland within the 1.5 km buffer zone had the greatest impact on turbidity, NH4+-N, and TP. While the reed wetland acted as the "sink" for intercepting and absorbing pollutants, it also released nitrogen into the 800 m buffer zone, which was the "source" of the pollutants. ④ The correlation between water quality indicators and land use structure in the rainy season was lower than that in the dry season. This was due to the dilution effect of the upstream reservoir discharging in the rainy season, which weakened the impact of pollutants in the rainfall runoff on the water quality of Baiyangdian Lake.

Identifying surface water and groundwater interactions using multiple experimental methods in the riparian zone of the polluted and disturbed Shaying River, China.

Identifying groundwater (GW)-surface water (SW) interactions in riparian zones is important for assessing the transport pathways of pollutants and all potential biochemical processes, particularly in rivers with artificially controlled water levels. In this study, we constructed two monitoring transects along the nitrogen-polluted Shaying River, China. The GW-SW interactions were qualitatively and quantitatively characterized through an intensive 2-y monitoring program. The monitoring indices included water level, hydrochemical parameters, isotopes (δ18O, δD, and 222Rn) and microbial community structures. The results showed that the sluice altered the GW-SW interactions in the riparian zone. A decrease in river level occurs during the flood season owing to sluice regulation, resulting in discharge of riparian GW into the river. The water level, hydrochemistry, isotopes, and microbial community structures in near-river wells were similar to those in the river, indicating mixing of the river water with the riparian GW. As the distance from the river increased, the percentage of river water in the riparian GW decreased, whereas the GW residence time increased. We found that nitrogen may be easily transported through the GW-SW interactions, acting as a sluice regulator. Nitrogen stored in river water may be removed or diluted by mixing GW and rainwater during the flood season. As the residence time of the infiltrated river in the riparian aquifer increased, nitrate removal increased. Identifying the GW-SW interactions is crucial for water resource regulation and for further tracing the transport of contaminants such as nitrogen in the historically polluted Shaying River.

Could the hydrological conditions of Lake Baiyangdian support a booming metropolis?

In 2017, the Chinese government announced the development of another metropolis called Xiong'an New Area (XNA) to relieve the population and service pressures affecting Beijing. By the programs of the Chinese governments, the largest natural freshwater wetland of the XNA, Lake Baiyangdian (BYD), will provide the key ecosystem services for the region. However, whether the hydrological conditions of BYD can support this booming metropolis is still unclear. The hydrological condition evolutions and the ecological water demand of BYD in the near future were evaluated. The results showed that to maintain the ecosystem function of BYD and provide ecological services for the XNA, the annual ecological water demands of BYD ranged from 3.10 × 108 m3 to 6.35 × 108 m3 under different water exchange scenarios. Due to the insufficient water resources within the watershed, under the scenario of a 1.0 time year-1 frequency of lake water exchange, in wet years, normal flow years and dry years 1.32 × 108 m3, 2.10 × 108 m3 and 3.38 × 108 m3 of external water from the Yellow and Yangtze Rivers must be transferred into BYD to satisfy the ecological restoration of the XNA, and the costs may be as much as 77-277 million RMB (11.0-39.57 million USD) per year. The predicted results show that the external water demands may decrease slightly by 0.58 × 108-0.95 × 108 m3 year-1 and 1.02 × 108-1.19 × 108 m3 year-1 in the 2030s and 2050s, respectively. Agricultural water consumption reduction, inflow water quality improvement and the intelligent use and management of urban reclaimed water are necessary for maintaining the ecosystem function of BYD, and externally transferred water may be a potential factor needed to support the growing XNA.

Spatiotemporal heterogeneity of nitrogen transformation potentials in a freshwater estuarine system.

Under the influence of water diversion, the microbial community composition of estuarine waters and sediments might have complex spatiotemporal variations. Microbial interactions with N are significant for lake water quality. Therefore, the largest lake receiving seasonal water diversion in the North China Plain was selected as the study area. Based on 16S rRNA high-throughput sequencing and metagenomic sequencing techniques, this study analysed temporal (June-December) and spatial (estuary-pelagic zone) changes in the microbial community and functional gene composition of water and sediment. The results showed that the water microbial community composition had temporality, while sediment microbes had spatiality. The main causes of temporality in the aquatic microbial community were temperature and nitrate-N concentration, while those of sediment were flow velocity and N content. Additionally, there were complex interactions between microbial communities and N. In water, temporal variation in the relative abundance of N-related functional genes might have indirectly contributed to inorganic N composition in June (nitrite-N > ammonia-N > nitrate-N) and August (nitrite-N > nitrate-N > ammonia-N). High nitrate-N concentrations in December influenced the microbial community composition. In sediment, the estuary had higher N functional genes than the pelagic estuary, creating a relatively active N cycle and reducing total N levels in the estuary. This study revealed a potentially overlooked N sink and a flow velocity threshold that has great impacts on microbial community composition. This research contributes to a deeper understanding of the estuarine N cycle under the influence of water diversions, with implications for the calculation of global N balances and the management of lake water environments.

Psychological stress responses of medical staff after workplace violence: a longitudinal study.

OBJECTIVE: To explore the occurrence and dynamic trends of psychological stress responses of medical staff experiencing workplace violence at different time points. METHODS: A longitudinal study of 23 medical workers who experienced workplace violence was conducted. The perceived stress scale (PSS-4), posttraumatic stress disorder checklist for DSM-5 (PCL-5), and hospital anxiety and depression scale (HADS) were used to measure the medical workers' psychological perception of pressure, posttraumatic stress symptoms, anxiety, and depression at the time of exposure to violence, at 1 month, 2 months, and 4 months after exposure in the workplace, respectively. Repeated measures analysis of variance was applied to analyze psychological stress response and temporal effect. Factors influencing psychological stress responses were analyzed. RESULTS: The scores of PSS-4, PCL-5, HADS-anxiety, and HADS-depression of medical staff exposed to violence began to increase at the time of exposure, peaked 1 month after exposure, and gradually decreased 2 months and 4 months after exposure (all P<0.05). The main influencing factors were being nurses, physical violence, working years ≤5, and being female. CONCLUSION: Effective interventions for medical staff should be made up to 1 month after exposure to workplace violence when the psychological stress responses are the highest.

Slight flow volume rises increase nitrogen loading to nitrogen-rich river, while dramatic flow volume rises promote nitrogen consumption.

Concentrated rainfall and water transfer projects result in slight and dramatic increases in flow volume over short periods of time, causing nitrogen recontamination in the water-receiving areas of nitrogen-rich rivers. This study coupled hydrodynamic and biochemical reaction models to construct a model for quantifying diffusive transport and transformation fluxes of nitrogen across the water-sediment interface and analysed possible changes in the relative abundance of microbial functional genes using high-throughput sequencing techniques. In this study, the processes of ammonium (NH4+-N) and nitrate (NO3--N) nitrogen release and sedimentation with resuspended particles, as well as mineralisation, nitrification, and denitrification processes were investigated at the water-sediment interface in the Fu River during slight and dramatic increases in flow volume caused by concentrated rainfall and water diversion projects. Specifically, a slight flow volume rise increased the release of NH4+-N from the sediment, inhibited sedimentation of NO3--N, decreased the mineralisation rate, increased the nitrification rate, and had little effect on the denitrification process, ultimately increasing the nitrogen load to the river water. A dramatic increase in flow volume simultaneously increased NH4+-N and NO3--N exchange fluxes, inhibited the mineralisation process, promoted nitrification-denitrification processes, and increased inorganic nitrogen consumption in the river. This study provides a solution for the re-pollution of rivers that occurs during the implementation of reservoir management and water diversion projects. Furthermore, these results indicate a potential global nitrogen sink that may have been overlooked.

Effect of overall nursing combined with acupressure in preventing postpartum urinary retention.

OBJECTIVES: This study investigated the effects of overall nursing care combined with acupressure in preventing postpartum urinary retention. METHODS: A total of 200 parturients with vaginal delivery in our hospital from March to October 2019 were enrolled and randomized to a control group and an observation group with 100 cases each. The control group received conventional nursing, while the observation group was also given "overall" nursing combined with acupressure. The two groups were compared in the incidence of urinary retention, time to the first urination, first urine volume, residual urine volume, pelvic floor muscle fiber contraction time, satisfaction, and treatment efficiency. RESULTS: The two groups presented no significant difference in general information (P>0.05). Compared to the control group, the observation group showed a lower incidence of urinary retention and experienced an earlier time to first urination (both P<0.001). A significantly smaller residual urine volume was observed in the observation group as compared to controls at 4 h and 12 h after delivery (P<0.05). The observation group outperformed the control group in terms of pelvic floor muscle fiber contraction duration (P<0.001). Moreover, the observation group showed a treatment efficiency and nursing satisfaction superior to the control group (P<0.05). CONCLUSIONS: Overall nursing care combined with acupressure can exert strong positive effects on the incidence of postpartum urinary retention, time to the first urination, and residual urine volume in parturients with vaginal delivery and improve their satisfaction.

Numerical modeling of changes in groundwater storage and nitrate load in the unconfined aquifer near a river receiving reclaimed water.

Reclaimed water (RW) has been widely used as an alternative water resource to recharge rivers in mega-city Beijing. At the same time, the RW also recharges the ambient aquifers through riverbank filtration and modifies the subsurface hydrodynamic system and hydrochemical characteristics. To assess the impact of RW recharge on the unconfined groundwater system, we conducted a 3D groundwater flow and solute transport model based on 10 years of sequenced groundwater monitoring data to analyze the changes of the groundwater table, Cl- loads, and NO3-N loads in the shallow aquifer after RW recharge to the river channel. The results show that the groundwater table around the river channel elevated by about 3-4 m quickly after RW recharge from Dec. 2007 to Dec. 2009, and then remained stable due to the continuous RW infiltration. However, the unconfined groundwater storage still declined overall from 2007 to 2014 due to groundwater exploitation. The storage began to recover after groundwater extraction reduction, rising from 3.76 × 108 m3 at the end of 2014 to 3.85 × 108 m3 at the end of 2017. Cl- concentrations varied from 5-75 mg/L before RW recharge to 50-130 mg/L in 2 years (2007-2009), and then remained stable. The zones of the unconfined groundwater quality affected by RW infiltration increased from 11.7 km2 in 2008 to 26.7 km2 in 2017. Cl- loads in the zone increased from 1.8 × 103 t in 2008 to 3.8 × 103 t in 2017, while NO3-N loads decreased from 29.8 t in 2008 to 11.9 t in 2017 annually. We determined the maximum area of the unconfined groundwater quality affected by RW, and groundwater outside this area not affected by RW recharge keeps its original state. The RW recharge to the river channel in the study area is beneficial to increase the groundwater table and unconfined groundwater storage with lesser environmental impacts.

A Fast Hybrid Feature Selection Based on Correlation-Guided Clustering and Particle Swarm Optimization for High-Dimensional Data.

The "curse of dimensionality" and the high computational cost have still limited the application of the evolutionary algorithm in high-dimensional feature selection (FS) problems. This article proposes a new three-phase hybrid FS algorithm based on correlation-guided clustering and particle swarm optimization (PSO) (HFS-C-P) to tackle the above two problems at the same time. To this end, three kinds of FS methods are effectively integrated into the proposed algorithm based on their respective advantages. In the first and second phases, a filter FS method and a feature clustering-based method with low computational cost are designed to reduce the search space used by the third phase. After that, the third phase applies oneself to finding an optimal feature subset by using an evolutionary algorithm with the global searchability. Moreover, a symmetric uncertainty-based feature deletion method, a fast correlation-guided feature clustering strategy, and an improved integer PSO are developed to improve the performance of the three phases, respectively. Finally, the proposed algorithm is validated on 18 publicly available real-world datasets in comparison with nine FS algorithms. Experimental results show that the proposed algorithm can obtain a good feature subset with the lowest computational cost.

The protective effect of ulinastatin combined with Xuebijing on myocardial injuries in patients with severe pneumonia.

OBJECTIVE: To explore the protective effect of ulinastatin combined with Xuebijing on myocardial injuries in patients with severe pneumonia. METHODS: The clinical data of 86 patients with severe pneumonia treated in our hospital were analyzed retrospectively. According to the treatment method each patient was administered, they were divided into a control group (43 cases, routine treatment + Xuebijing) and an observation group (43 cases, routine treatment + Xuebijing + ulinastatin). All the patients were treated for 2 weeks. The clinical efficacy, the inflammatory factor levels (TNF-α, C-reactive protein (CRP), and procalcitonin (PCT)), the myocardial index levels (creatine kinase-myocardial band (CK-MB), lactic dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (α-HBDE), N-terminal pro-brain natriuretic peptide (NT-proBNP), and cardiac troponin I (cTn I)), the blood gas index levels (arterial partial pressure of oxygen (PaO2), oxygen saturation (SaO2), and oxygenation index (OI)), the coagulation functions (prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB)) and the acute physiology and chronic health evaluation (APACHE-II) scores were compared between the two groups. RESULTS: After the treatment, the total effective rate in the observation group was higher than it was in the control group (P<0.05). After the treatment, the serum TNF-α, CRP, PCT, CK-MB, LDH, α-HBDE, NT-proBNP, and cTnI levels and the APACHE-II scores were decreased in the two groups, and they were even lower in the observation group (all P<0.05). The PaO2, SaO2, and OI levels were increased in the two groups, and they were higher in the observation group (all P<0.05). Compared with before the treatment, the patients' PT and APTT levels in both groups were prolonged after the treatment, and the observation group was longer than the control group. The plasma FIB levels were decreased in both groups, and they were lower in the observation group than in the control group (P<0.05). CONCLUSION: Ulinastatin combined with Xuebijing can significantly alleviate pulmonary inflammation, improve the blood gas, and protect the damaged myocardia in patients with severe pneumonia.

Impacts of storm events on chlorophyll-a variations and controlling factors for algal bloom in a river receiving reclaimed water.

Harmful algal bloom is prevalent in the reclaimed-water-source (RWS) river caused by the excessive nutrient's inputs. Rainfall water may be the sole nutrient-diluted water source for the RWS river. However, the effects of storm events on the algal bloom in the RWS river are poorly understood. This study presents chlorophyll-a (Chl-a) variations before, during, and after the initial storm events (Pre-storm, In-storm, and Post-storm) at four representative sites with distinct hydraulic conditions in a dam-regulated RWS river system, Beijing. The response of Chl-a to the initial storm events mostly depends on the ecosystem status that caused by the river hydraulic properties. The upstream is more river-like and downstream is more lake-like. In the river-like system, elevated water temperature (WT, increased by 2 %) could support the dominating algae (diatom) growth (Chl-a increased by 130 %) from Pre-storm to In-storm period. In the lake-like system, the dominant algae (blue algae) declined (Chl-a sharply decreased by 96%-99 %) due to the lower WT (decreased by 3%-7%) and increased flow velocities from Pre-storm to In-storm period. During the Post-storm period, the dominant algae break out (Chl-a surged by 20%-319 %) in the lake-like system caused by the recovered WT (increased by 3%-6%) and flow velocity. The occurrence of algal bloom can be predicted by the Random Forest (RF) model based on water quality parameters such as total nitrogen (TN). The thresholds of algal bloom for the Pre-storm, In-storm, and Post-storm periods were identified as 30 µg/L, 10 µg/L, and 10 µg/L, respectively. The two driven factors were WT and nitrate (NO3-N) for the Pre-storm period and were WT and TN for the In- & Post-storm periods. A higher risk of algal bloom is highlighted during the initial storm events in the RWS river. We propose recommendations for improving water quality in the RWS river systems under the climatic change.

Sources and migration of heavy metals in a karst water system under the threats of an abandoned Pb-Zn mine, Southwest China.

Water quality is of great concern under the threats of an abandoned Pb-Zn mine within a vulnerable karst area. This study focuses on tracing the sources, migration and relevant geochemical controls of heavy metals along with surface- and groundwater flow, and assessing their hazards posed to the environment by indexes of heavy metal pollution (HPI) and ecological risks (ERI). We analyzed the concentrations of lead (Pb), zinc (Zn), cadmium (Cd) and copper (Cu) in filtered and digested surface water (SW) and groundwater (GW) samples. Whilst sulfate concentrations, δ34SSO4 isotope, and other physical-chemical parameters were measured in filtered SW and GW. Clearly elevated concentrations of Zn and Cd have been observed in the upstream of the Sidi River (max. 1540.3/1676.7, and 19.9/19.4 µg/L, for filtered/digested contents, respectively), and that of digested Pb and Cu (max. 17.8 and 114.6 µg/L, respectively) in the downstream karst groundwater. Zn and Cd are likely introduced by the Sidi River which is found mostly in the dissolved phase. While Pb and Cu are sourced from the remobilization of upper lying polluted soil which mostly existed in the particulate phase. Zn and Cd concentrations in the karst groundwater peak at the losing section while Pb and Cu in the river peaks at the gaining section as a result of metals transport with SW-GW exchange. Dilution significantly decreases total metals concentration in the non-karst area. Due to the buffer effect caused by carbonates dissolution and bacterial sulfate reduction, a steady neutral pH can reduce the concentrations of the dissolved metals in the karst area. The ERI and HPI assessments show an acceptable level for surface- and groundwater. A long-term observation on the contents of undissolved metals needs to be conducted in karst areas which are threatened by metal(s) mines.

Improved Nonlinear Extended State Observer-Based Sliding-Mode Rotary Control for the Rotation System of a Hydraulic Roofbolter.

This paper develops a sliding-mode control with an improved nonlinear extended state observer (SMC-INESO) for the rotation system of a hydraulic roofbolter with dead-zones, uncertain gain, and disturbances, with the purpose of improving tracking performance. Firstly, the rotation system is modeled to compensate for dead-zone nonlinearity. Then, we present an improved nonlinear extended state observer to estimate disturbances of the rotation system in real time. Moreover, a proportional-integral-differential sliding-mode surface is introduced and an improved sliding-mode reaching law is designed. Based on this, a sliding-mode control law is developed. In order to eliminate the influence of estimation error and uncertain gain, we design two adaptation laws based on the sliding-mode surface and the estimated states. Finally, the effectiveness of the proposed SMC-INESO is verified through comparative simulation studies.

Subsurface hydrological processes and groundwater residence time in a coastal alluvium aquifer: Evidence from environmental tracers (δ18O, δ2H, CFCs, 3H) combined with hydrochemistry.

As an important part of the water cycle, the hydrologic process and chemical compositions of groundwater have changed significantly due to the joint influence of climate change and human activities. Groundwater salinization becomes a serious threat to water security in coastal areas. In order to assess the relationships between surface water, groundwater and seawater in the coastal plain, we performed a synthesis study based on hydrochemical-isotopic data, hydro-dynamical records and environmental tracers. Deuterium and oxygen isotopes and water chemical indicators were used to identify pollution status, salt sources and migration processes. Radioactive isotopes and gaseous tracers were used to obtain reasonable groundwater age. With the help of multi-tracer approach, the surface-groundwater interaction, salinization of groundwater and nitrate pollution were identified in the Yang-Dai River plain, northern China. The estimated groundwater ages determined from chlorofluorocarbons (CFCs) and tritium (3H) ranges from 18 to 41 years in this area, suggesting a modern groundwater circulation. The spatial distribution of the groundwater age varies significantly due to horizontal hydrogeological heterogeneity. The total dissolved solids (TDS) content of the groundwater near the Well Field (average: 970 mg/L) was higher than the TDS values in samples derived from places located at an equivalent distance to the coastal line (average is 708 mg/L), which resulted from the vertical seawater intrusion through river channels and pollutant inputs from agriculture activities. The nitrate concentrations in groundwater were elevated up to 271 mg/L and increased with increasing groundwater age, which was another water environment problem that should be solved urgently but lacks sufficient attention for years. This study provides a conceptual model with a number of comparable hydrochemical information, which is significant for regional pollution control and water resources management.

Seasonal responses of maize growth and water use to elevated CO2 based on a coupled device with climate chamber and weighing lysimeters.

The increase in atmosphere carbon dioxide (CO2) concentrations has been the most important environmental change experienced by agricultural systems. It is still uncertain whether grain yield of the global food crop of maize will remain unchanged under a future elevated CO2 (eCO2) environment. A coupled device with climate chamber and weighing lysimeters was developed to explore the water-related yield responses of maize to eCO2. Two experiments were conducted via this device under eCO2 (700 ppm) and current CO2 (400 ppm) concentrations. Seasonal changes in multiple growth indicators and related hydrological processes were compared between these two experiments. The results showed that the eCO2 effects were not significant on several indicators, i.e., the leaf carbon (C) content, nitrogen (N) content, chlorophyll content, C/N ratio, net photosynthesis rate, and leaf area index over the entire growing season (p > 0.05). Nevertheless, the transpiration rate (Tr) significantly reduced during the seedling to filling stages but notably increased at the maturity stage due to eCO2 (p < 0.05). Significant reduction in crop height (mean of 15.9%, p < 0.05) associated with notable increases in stem diameter (mean of 14.9%, p < 0.05) were found throughout the growing season. Dry matter per corncob at the final harvest decreased slightly under eCO2 (mean of 7.7 g, p > 0.05). Soil water storage was not significantly conserved by the decline of Tr except during the filling stage. Soil evaporation was likely promoted by eCO2 that the total evapotranspiration changed little (1.2%) over the entire growing season. Although the leaf water use efficiency increased significantly at every growth stage (mean of 27.3%, p < 0.05), the grain yield and water productivity were not improved noticeably by eCO2. This study could provide significant insight into predicting future crop yield and hydrological changes under climate change.