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The dissolved oxygen (DO) concentration is an important index of water quality. It has a significant impact on the biodegradation process in water and the survival of aquatic organisms. Low DO concentrations often exist and may result in a deterioration in water quality and an increase in wastewater treatment expenses. An analysis of the oxygen transfer efficiency as correlated with the flow characteristics of a falling jet could help to solve these problems. Experiments related to oxygen transfer along a falling water jet were conducted, and the effects of the flowrate ( Q ), falling height ( H ) and initial DO concentration ( c u ) were considered. The results demonstrated that a falling jet in air could be an effective way of improving the DO concentration. The results also indicated that the oxygen transfer efficiency is linearly dependent on c u and has a negative exponential relation with H . To deeply analyze the oxygen transfer process, the jet disturbance process was divided into 3 parts for the first time based on flow features: a smooth zone, turbulent zone and breakup zone. The results showed that the jet outlet velocity had a limited influence on the smooth zone height but assisted in jet breakup. Thereafter, a correlation modeling DO reaeration along the falling jet considering jet disturbance characteristics was obtained. This correlation was also applied to predict the aeration efficiency in experimental cases from the literature and showed good agreement with the reported results.

First started in 1931, the Continuous Plankton Recorder (CPR) Survey is the longest-running and most geographically extensive marine plankton sampling program in the world. This pilot study investigates the feasibility of biomonitoring the spatiotemporal trends of marine pollution using archived CPR samples from the North Pacific. We selected specimens collected from three different locations (British Columbia Shelf, Northern Gulf of Alaska, and Aleutian Shelf) in the North Pacific between 2002 and 2020. Comprehensive profiling of the plankton chemical exposome was conducted using liquid and gas chromatography coupled with tandem mass spectrometry (LC-MS/MS and GC-MS/MS). Our results show that phthalates, plasticizers, persistent organic pollutants (POPs), pesticides, pharmaceuticals, and personal care products were present in the plankton exposome, and that many of these pollutants have decreased in amount over the last two decades, which was most pronounced for tri-n-butyl phosphate. In addition, the plankton exposome differed significantly by regional human activities, with the most polluted samples coming from the nearshore area. Exposome-wide association analysis revealed that bioaccumulation of environmental pollutants was highly correlated with the biomass of different plankton taxa. Overall, this study demonstrates that exposomic analysis of archived samples from the CPR Survey is effective for long-term biomonitoring of the spatial and temporal trends of environmental pollutants in the marine environment.

Ciprofloxacin (CIP) is a synthetically produced and widely prescribed antibiotic. Due to incomplete metabolism and gut absorption, a significant portion of the consumed CIP is excreted and released into the environment through wastewater. Vetiver grass has been reported to tolerate many organic and inorganic pollutants. Our objectives were to evaluate the potential of vetiver grass to remove CIP from aquatic media with the ultimate goal of developing a plant-based method for wastewater treatment. We also examined the potential degradation/transformation of CIP in the plant and the metabolic pathways impacted by CIP. Results show that vetiver grass removed more than 80% CIP within 30 days. Ciprofloxacin elicited a stress response by inducing antioxidant enzymes, and metabolic profiling indicated an impact on key metabolic pathways. Transformation products of CIP in vetiver tissue indicate the potential role of root-associated microorganisms as well as plant metabolism in CIP degradation.

Plant growth promoting bacteria (PGPB) provide multiple benefits in agriculture by enhancing crop productivity and nutrient content and suppressing the growth of pathogens. Development of beneficial plant-microbe interactions based on genomics, transcriptomics, proteomics and metabolomic data of both PGPB and host will lead to optimized microbial inoculants for enhancing crop yield and nutrient content. PGPB are promoted as a green technology which will reduce the use of chemical fertilizers thereby improving soil health. Although a significant increase in the use of PGPB in agriculture was observed in the last two decades, there is a dearth of long-term studies addressing the effects of PGPB on existing microbial community structure. It is likely that most or all PGPB are resistant to common antibiotics used to treat human diseases. Antibiotic resistance of PGPB may be due to the presence of antibiotic resistance genes and intrinsic resistance due to the presence of efflux pumps. The biological significance of resistance to antibiotics and metals and their relation to plant growth promoting activity, if any, is not known. The consequences of harboring antibiotic resistance may be negative if the trait is transferred to other soil or environmental bacteria. Strategies to develop PGPB strains with useful traits of plant growth promotion but without resistance to common antibiotics used by humans, would enhance agricultural productivity without the negative effects on the environment. Alternately, harboring antibiotic resistance may be positive if it is due to intrinsic resistance involving proteins which also have other functions. Antibiotic resistance of PGPB may be an essential trait if it is related to their plant growth promoting activity. Overall, there is a need to conduct large-scale screening of PGPB for antibiotic resistance and long-term studies to see the effect of the introduction of biofertilizers on native soil microbial community.

The success of river habitat restoration relies on accurate assessment proxies. However, determining how to quantitatively assess the impact of multiple stressors during flood discharge from high dams in riverine ecosystems and where and how to implement more reliable recovery interventions remain challenges. Here, we developed a bottom-up mechanistic framework for assessing the effects of total dissolved gas supersaturation (TDGS) and hydrodynamics on fish habitat quality and applied it to the downstream river reach of the Xiangjiaba Dam in Southwest China. The results showed that the available habitat area of river sturgeon was the smallest, while Chinese sucker had the largest available habitat area among the three target species under all discharge scenarios. Although the TDGS levels were evenly mixed laterally, the habitat suitability index indicated that the suitable habitats were primarily within both sides of the river reach under all scenarios, which is contrary to findings based on the traditional TDGS risk assessment model. The traditional TDGS risk assessment model overestimates the impact of dams on habitats. This divergence reflected the sensitivity of the habitat assessment to fish habitat preferences, fish tolerance to TDGS and the biological response of fish under TDGS. Additionally, the priority areas for restoration can be identified by habitat suitability index with lower values. We simulated twenty-four schemes and found that interventions such as stone groups, ecological spur dike, water-retaining weir and river dredging can enhance habitat suitability for fish species under multiple stressors, providing novel insights into where and how to mitigate the impact of TDGS. Our findings offer a transferable framework for the quantitative evaluation of fish habitat and implementation of restoration management during dam flood discharge periods, thus providing a new perspective for biodiversity conservation and habitat restoration in dam-regulated rivers with TDGS around the world.

Electrochemically active SnO2 materials are prospective alternatives for graphite toward better flexible LIBs. However, significant volume changes and structural pulverization restrict the cycling stability and high capacity of SnO2. Here, we report a binder and conductive additive free core-shell N-doped carbon @SnO2 hybrid paper by a subtle coaxial-electrospinning method. Core-shell N-doped C@SnO2 fibers not only offer rapid ionic transport and sufficient buffer space for the volume expansion during the Li insertion and extraction reactions, but also enable high flexibility against both compression and bending deformation. As an anode for LIBs, the hybrid materials delivered a large initial capacity of 1799 mAhg−1 with capacity retention of 729 mAhg−1 after 100 cycles at a current rate of 390.5 mAg−1. More importantly, flexible N-doped C@SnO2 fabrics exhibit excellent electrochemical performance even after a rough treatment, suggesting a facile strategy for the fabrication of electrochemically stable electrodes for flexible LIBs.

The development of cascade hydropower in the Yalong River has changed the hydrological regime of the river and sharply reduced the Coreius guichenoti population dwelling downstream of the JinPing II power station. In this paper, an eco-hydrological index system for C. guichenoti habitat was constructed based on Indicators of Hydrologic Alteration (IHA) and Environment Flow Components (EFC), which aimed to coordinate the processes of ecological hydrological and water temperature variations to guarantee the oviposition of C. guichenoti. The analysis revealed that the suitable rise rate and fall rate intervals, which are dimensionless parameters, were 0.05–0.10 and 0.01–0.03, respectively, during the spawning period. The rise and fall durations were both 1–2 days, the cycle of water fluctuations was 3–5 days, the flow pulse duration was 5–7 days, the flow pulse rise rate was 0.56–0.65, and the flow pulse fall rate was 0.23–0.50. Then, the Instream Flow Incremental Methodology (IFIM) method was used to calculate the ecological base flow during the C. guichenoti spawning period. Moreover, the ecological flow regime for C. guichenoti downstream of the JinPing II power station during the spawning period was determined based on eco-hydrological indicators and water temperature requirements. These results showed that the ecological flow regime could not only guarantee oviposition but also meet the drifting conditions required for eggs, and therefore, the ecological operation of diversion-type hydropower stations and cascade hydropower stations needs to be given more attention to provide suitable spawning conditions in target fish habitats.

Spillway discharge leads to total dissolved gas (TDG) supersaturation in the plunge pool, and these gases cannot dissipate to restore equilibrium after traveling tens or even hundreds of kilometers downstream of the spillway. Supersaturated TDG is detrimental to fish and may cause gas bubble disease. The negative impact is enhanced when cascade reservoirs are in operation. Field observations of the TDG concentrations were performed in the lower reaches of the Dadu River in the summers of 2009 and 2012. The relationships between the TDG concentration and various impact factors were analyzed. Increasing the unit discharge rate and downstream water depth can accelerate the production of TDG supersaturation, a ski-jump was a better pattern for dissipating energy than an underflow, and the power generation system did not contribute to the TDG production. The TDG dissipation showed that the dissipation coefficient increased with an increasing flow rate. An investigation was conducted to explore the cumulative effect of a hydropower cascade. A controlled cascade reduced the TDG production by reducing the occurrence of a discharge at the downstream cascade is beneficial. Based on the field observations, which were focused on operational regulation, mitigation measures for TDG supersaturation for the watershed management of a hydropower cascade were suggested and discussed.

Uncontrolled cardiac fibrosis following myocardial infarction (MI) is a critical pathological change leading to heart failure. Current pharmacotherapies are limited by unsatisfactory efficacy and undesired systemic side effects. Astaxanthin (ASX) is a natural carotenoid with strong antioxidant and anti-inflammatory activities. The effects of ASX on MI-induced cardiac fibrosis and the underlying mechanisms remain largely unknown. In this study, after the establishment of MI model, mice were administrated with ASX (200 mg/kg⋅d) for 4 weeks. We found that ASX treatment attenuated cardiac fibrosis and improved heart function following MI, as evidenced by reduced collagen I/III ratio, hydroxyproline content and left ventricular end diastolic pressure (LVEDP). Lipidomic analysis revealed the overaccumulation of myocardial ceramides in mice with cardiac fibrosis, which was normalized by ASX treatment. Molecular docking analysis showed that ASX produced a tight fit in the pocket of sphingomyelin phosphodiesterase 1 (SMPD1), a key enzyme in the production of ceramides. Western blot analysis confirmed the significant inhibition of SMPD1 expression by ASX. Furthermore, MI-induced overexpression of transforming growth factor β1 (TGF-β1) and phosphorylated SMAD2/3 were attenuated by ASX administration. SMPD1 knockout (KO) abrogated the beneficial effect of ASX. Taken together, our results suggest that the cardioprotective effects of ASX are mediated by SMPD1 through the indirection inhibition of TGF- β1/SMAD signaling cascade.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease caused by the SFTS virus (SFTSV) of the family Bunyaviridae. Since the virus was first isolated in 2009, it has become widespread in China, with an increasing number of cases year on year. Although the disease has been researched extensively in past years, there are still no effective measures to suppress the epidemic situation. This article reports a pilot study of comprehensive measures, including health education and risk communication, weed removal, livestock management, and tick control, to prevent this emerging disease in an endemic region of China. The density of ticks decreased dramatically month by month after acaricides were sprayed in the areas surrounding recreational and agricultural settings. The number of SFTS cases and villages involved declined in the years after the integrated measures were applied. Comprehensive measures, especially community-based tick control, may be a promising means of preventing SFTS in endemic regions.

Lead (Pb) contamination of residential soils in United States is attributed to use of Pb based paints prior to 1978 and their deterioration and accumulation in surface soils. Exposure to Pb due to ingestion and inhalation of Pb laden soil and dust causes neurological disorders, renal disorders, developmental and behavioral problems, particularly in children under the age of six. Vetiver grass is one of the leading choices for Pb remediation due to its ability to hyperaccumulate Pb, in addition to high biomass. In order to understand the effect of Pb on vetiver metabolic pathways, we compared the global metabolic changes in vetiver with that of maize, a Pb susceptible plant under Pb stress. Vetiver showed massive increase in levels of key metabolites in response to Pb, including amino acids, organic acids and coenzymes. Maize showed very modest increase in some of the same metabolites, and no change in others. The results provide the first indication of the difference in metabolic response of the hyperaccumulator, vetiver to lead stress as compared to maize.

A laterally-averaged 2D water temperature model coupled with an ice cover module was used to investigate the influences of the Fengman Dam reconstruction on its thermal regime. Variations of the thermal-ice regime and outflow temperature under typical hydro-metrological conditions were simulated and validated with field data. Due to the partial dismantling of the old dam after the reconstruction, the intake water is primarily taken from the surface layer of the reservoir. As a result, the total heat storage of the reservoir throughout the year and the outflow temperature from January to March will decrease. Furthermore, the low outflow temperature in the winter will result in a decline of the downstream water temperature and negatively impact the rime scenery near Jilin City. In order to increase the outflow temperature in winter, an operation scheme that combined the new intake with the old intake of the III-phase project of old dam was discussed. The results indicated that this scheme could increase the outflow temperature to ensure a 70 km open channel in the downstream river in a typical winter, and eliminated the negative effects on the rime scenery.

Vitamins are essential molecules required for human metabolism such as energy production, immune system and cell formation. Accurate vitamin analysis is critical for disease diagnosis, nutrients assessment, as well as food and drug production. This review gives an overview of the recent developments in the use of capillary electrophoresis combined with different detection techniques for the analysis of vitamins. The period covers mid-2007 until mid-2017. Different separation modes are discussed for the analysis of water-soluble vitamins and fat-soluble vitamins. On-line sample concentration for sensitive analysis is also described. The applications include the analysis of pharmaceutical, dietary supplement and biological samples. ispartof: Journal of Pharmaceutical and Biomedical Analysis vol:147 pages:278-287 ispartof: location:England status: published

Spills of dams often lead to dissolved gases supersaturation of water downstream. Owing to the slow dissipation, the impact of supersaturated dissolved gases in cascade hydropower development basin may be basin-wide, which can cause fish mortality. It is imperative to explore high-efficiency technology to reduce the saturation of dissolved gases. Stepped cascades are recognized as high potential air-water mass transfer exchangers, their application focused on re-oxygenation. In the literature, stepped cascades weren't applied in the dissipation of supersaturated dissolved gases yet. In this study, 89 groups of supersaturated dissolved oxygen degassing experiments were carried out in three different types of stepped cascades. From the top to the bottom of stepped cascades, supersaturated dissolved oxygen dissipated rapidly and the most significant drop was 63.3%. Degasification efficiency was defined by the percent saturation of dissolved oxygen measured on different steps and the equilibrium saturation. The variation law of degasification efficiency of supersaturated dissolved oxygen was discussed under different flow regimes. The degasification efficiency showed a positive relation with energy dissipation efficiency and the length of aerated flow region. Then a correlation model to predict the degasification efficiency was established with which the square of the correlation coefficient ( R 2 ) between calculated and experimental values is 0.93. Finally, two possible applied scenarios of stepped cascades in natural rivers were listed, the model was proved practical. The results of this study can provide suggestions for the construction, operation and management of hydropower development considering ecological-environmental protection.

The urbanization process of the Hanjiang Basin is speeding up and facing many challenges. It is necessary to take active actions to realize the balance between urbanization development and water environment protection. This paper aims to establish a comprehensive evaluation model of urbanization and water environment (UAWE) and explore the development of UAWE in the Hanjiang Basin in China from 2010 to 2018. In terms of methodology, these evaluation models are combined with the Coupling coordination degree model (CCDM), Exploratory Spatial Data Analysis (ESDA), and Geographically and Temporally Weighted Regression (GTWR) to measure and analyze the coupling degree (CD) and spatiotemporal heterogeneity of UAWE. Our findings include the following: (1) From 2010 to 2018, in all regions of the Hanjiang Basin, urbanization showed a gradual upward trend. Among Them, the comprehensive urbanization index (CUI) of Xiangyang increased by 25.37%. (2) The comprehensive water environment index (CWEI) presents a fluctuating growth, with the rate of increase in Jingmen's reaching 17.44%. (3) There is heterogeneity in time and space between cities in the Hanjiang Basin, and the positive interaction effect of UAWE is mainly focused on the middle and lower reaches of the Hanjiang River. (4) Coupling coordination degree (CCD) in the basin shows an increasing trend, and the areas with high CCD are mainly concentrated in Xiangyang and Xiantao. (5) ESDA shows that the CCD among cities in the basin has spatial correlation and heterogeneity, and the regions with similar CCD tend to be distributed centrally in space.

58Ni39Ti-3Hf alloy system has been proposed as an alternative for superelastic 60NiTi used in load-bearing applications. This research was focused on the development of heat treatment procedures leading to 58Ni39Ti-3Hf parts with maximum possible hardness values. Meanwhile, the relations existing between the heat treatment – microstructure – hardness of 58Ni39Ti-3Hf as compared to baseline 60NiTi were also investigated. These were done by applying the solution and consequent aging treatments on the studied alloy systems at different temperatures and for different times. The microstructure and hardness of the treated samples were, in the next step, analyzed by applying electron probe micro-analyzer (EPMA), energy dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and macro hardness testing techniques. It was understood that applying solution treatments at temperatures above about 1000 °C resulted in the relatively full dissolution of Ni-rich phases such as Ni3Ti and Ni3Ti2, existing in the microstructure of as-received parts, in the NiTi matrix of 60NiTi. On the other hand, for 58Ni39Ti-3Hf, temperatures above about 900 °C appeared to be adequate to solve these Ni-rich phases in the NiTi matrix. Applying aging treatments had either no significant effect on the hardness of solution treated 60NiTi samples (~58 HRC) or reduced their values; after coarsening of Ni4Ti3 particles formed in NiTi matrix and their transformation to Ni3Ti and Ni3Ti2 phases. On the other hand, some of the applied aging treatments could increase the hardness values of the solution treated 58Ni39Ti-3Hf alloys (~54 HRC). The maximum value of hardness (~59 HRC) for the aged 58Ni39Ti-3Hf parts was obtained for the ones treated at 500 °C for just 0.25 h. This level of obtained hardness is comparable to that of solution treated 60NiTi. A delayed precipitation of Ni3Ti and/or Ni3Ti2 phases was noted in aged 58Ni39Ti-3Hf alloy system as compared to 60NiTi.

The estimation of non-point source pollution loads into the Danjiangkou Reservoir is highly significant to environmental protection in the watershed. In order to overcome the drawbacks of traditional watershed numerical models, a base flow separation method was established coupled with a digital filtering method and a flux method. The digital filtering method has been used to separate the base flows of the Hanjiang, Tianhe, Duhe, Danjiang, Laoguan, and Qihe rivers. Based on daily discharge, base flow, and pollutant concentration data, the flux method was used to calculate the point source pollution load and non-point source pollution load. The results show that: (1) In the year 2013, the total inflow of the six rivers mentioned above accounted for 95.9% of the total inflow to the Danjiangkou Reservoir. The total pollution loads of chemical oxygen demand (COD Mn ) and total phosphorus (TP) from the six rivers were 58.20 × 10 3 t and 1.863 × 10 3 t, respectively, and the non-point source pollution loads were 39.82 × 10 3 t and 1.544 × 10 3 t, respectively, indicating that the non-point source pollution is a major factor (with a contribution rate of 68.4% for COD Mn and 82.9% for TP). (2) The Hanjiang River is the most significant contributor of pollution loads to the Danjiangkou Reservoir, and its COD Mn and TP contribution rates reached 79.3% and 83.2%, respectively. The Duhe River took the second place. (3) Non-point source pollution mainly occurred in the wet season in 2013, accounting for 80.8% and 90.9% of the total pollution loads of COD Mn and TP, respectively. It is concluded that the emphasis of pollution control should be placed on non-point source pollution.

A novel strengthening method was proposed to improve the shear behaviors of hollow slab beam bridges through filling the hollow with high-performance self-consolidating cementitious composites. The strengthening effect was evaluated through a field loading experiment and long-term monitoring. Some important parameters were compared and analyzed before and after the strengthening, including the principal stress of the bridge web, the strain response of beam bottom, the mid-span deflection and the transverse connection between the beams. The experimental results showed that the principal stress of the bridge was decreased by more than 50% compared with that before the strengthening. Under different loading conditions, the strain response of each slab beam bottom was decreased in different degrees, with a reduction range between 20% and 60%. The mid-span deflection of the bridge decreased by 10%-25% after the strengthening. Through the analysis of the transverse distribution of the strain on the beam bottom, the strengthening method also improved the lateral connection of the bridge in a certain extent. In addition, it was found that the long-term effectiveness of the strengthening method is verified through more than a year of monitoring.

Total dissolved gas (TDG) supersaturation caused by the operation of hydropower stations can threaten the survival and swimming performance of fish species. Different modes of hydropower flood discharges (regular vs. intermittent) from the Dagangshan hydropower station in China were studied in July and September 2017 to study the impact of TDG supersaturation on two native fish species in the downstream Dadu River. The average TDG supersaturation value was 114.3% in July under the regular discharge mode. In September, the supersaturation of TDG fluctuated in response to the intermittent discharge mode with an average TDG of 119.3%. Apparent gas bubble trauma was found on young-of-the-year (YOY) Prenant's schizothoracin and elongate loach in cages at different water depths during the flood discharge period. The mortality rate of YOY Prenant's schizothoracin and elongate loach in cages with water depths of 0–1 m were 16.25% and 2.5%, respectively, in July. The fluctuating TDG levels with higher peaks in September caused higher fish mortality rates. The final mortality rates of YOY Prenant's schizothoracin and elongate loach in cages with water depths of 0–1 m were 75% and 33.75%, respectively. Fish in the cages at a 0–3 m water depth survived better than those in the cages at a 0–1 m water depth. The critical swimming speeds (Ucrit) of YOY Prenant's schizothoracin and elongate loach without exposure to TDG supersaturation were 11.64 and 16.76 BL s−1, respectively. Ucrit decreased significantly after experiencing the flood discharge period and recovered to the normal level after experiencing the corresponding interval period.

Total dissolved gas (TDG) supersaturation caused by dam operations can cause fish gas bubble disease (GBD) and even fish kill. Few studies have examined the effects on pelagic species. Here, we examined the tolerance and avoidance characteristics of silver carp (Hypophthalmichthys molitrix), a pelagic fish widely distributed in the Yangtze River basin in China, under stress caused by TDG supersaturation. Silver carp had an average mortality rate of 7.5% ± 1.8%, 92.5% ± 1.8%, and 97.5% ± 1.8% under 130%, 140% and 150% TDG supersaturation for 72 h of exposure, respectively. The average median lethal time (LT50) of silver carp was 18.1 h and 8.0 h under 140% and 150% TDG supersaturation, respectively. Bubbles and congestion appeared in the fins, gills and skin of silver carp. Silver carp can detect and avoid high TDG supersaturation. Significant avoidance behaviors were displayed by silver carp and the final avoidance rate was over 80% under 130% or above TDG conditions. The results of this study indicate that 130% TDG supersaturation triggered silver carp avoidance behaviors, and can be considered as the tolerance threshold.

The survival of aquatic biota in different life history stages depends on food availability, water quantity and specific hydrological conditions, and is particularly susceptible in degraded rivers due to the development of hydropower or are sensitive to climate change. Habitats with limited food availability and restricted feeding opportunities can strongly affect the habitat carrying capacity and fish growth with consequences for spawning. Few environmental flow regime frameworks are available that closely link bait and feeding opportunities to fish foraging habitat. In addition, river restoration has been widely implemented to resolve the conflict between ecological demand and power generation benefits. Nevertheless, whether in-stream structures are still suitable for the joint operation of foraging and spawning habitats remains unclear. In this study, a framework to integrate the requirements of both spawning and foraging habitats into environmental flow regime assessments was proposed by coupling the bait supply, fish spawning and fish feeding opportunities. Here, we used the Batang Reservoir, located in the Tibetan Plateau, as an example to determine the environmental flow regimes. The environmental flow regimes during Periods I, II and III for the conservation of the life history stages of Schizothorax dolichonem were determined, which provided high-quality food and was beneficial for increasing the probability of restoration success. After the implementation of measures, the ecological base flow rate decreased from 171.80 m3/s, 206.00 m3/s and 257.70 m3/s to 138.00 m3/s, 206.00 m3/s and 206.00 m3/s in Periods I, II and III, respectively. We concluded that traditional river restoration with the use of in-stream structures is still suitable for the joint operation of spawning and foraging habitats, but the design selection and placement of in-stream structures should be preoptimized. The framework proposed will help managers evaluate habitat conservation to protect degraded rivers or help develop strategies to build resilience to climate change.

Equiatomic and near-equiatomic NiTinol alloys, mainly due to the exhibition of adjustable mechanical and thermal shape memory properties, are widely exploited to produce different smart and functional devices. Laser powder bed fusion technique was used in this research to process dense NiTinol parts from a prealloyed near-equiatomic NiTi powder, using three different volumetric energy densities. In the next step, samples, processed using a specific set of printing parameters, were annealed using two different procedures. Effects of different used processing volumetric energy densities and post-processing heat treatments on the microstructural properties, phase composition, crystallographic information, phase transformation behavior and hardness of the processed samples were investigated. As-printed Parts with Ni contents ranging from 55.12 to 55.27 wt%, density higher than at least 96% of theoretical and a similar phase structure as that of used powder, dominated by austenitic NiTi, were obtained. Applying a hot isostatic processing treatment at 1100 °C for 4 h or annealing the samples in a pressureless sintering furnace, working under a vacuum environment at the same temperature and holding time, had significant effects on the properties of the printed parts. These treatments, in addition to increasing the density of the printed samples, their average grain size and reducing the residual stresses, shifted the phase transformations to lower temperatures. These results suggest that post-printing heat treatments affect and, as similar to NiTinol alloys having Ni contents above 55.7 wt%, can be used as a strategy to alter the phase transformation temperatures of printed less Ni-rich near-equiatomic NiTinol alloys and consequently obtain NiTinol parts suitable for different applications.

17-4PH stainless steel parts, fabricated by selective laser melting, were subjected to the solution and aging treatments conducted under vacuum and hot isostatic pressing (HIP) conditions. The microstructure of as-built and heat-treated specimens were characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Mechanical properties were evaluated using microhardness and tensile testing. The relative density of the as-built samples was improved after the conduction of HIP treatment. Microstructural characterization showed that precipitates with the co-occurrences of Cu-, Mn-, Si- and Nb-enrichments were formed in the HIP-processed specimen. Results of mechanical testing indicated that a simultaneous improvement of tensile strength and ductility could be obtained through solutionizing and aging treatments done in the HIP followed by a high-pressure gas quenching. In addition, a significant enhancement of tensile strength without sacrificing ductility could be attained by combining solutionizing treatment done under high pressure and consequent aging followed with water cooling.

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress. Main methods: Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise treatment only to the DE group from the 1st day until the rats are killed. DDT levels in excrements, muscle, liver, serum, and hearts were analyzed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels were determined. Aerobic exercise accelerated the degradation of DDT primarily to DDE due to better oxygen availability and aerobic condition and promoted the degradation of DDT. Cumulative oxidative damage of DDT and exercise led to significant decrease of SOD level. Exercise resulted in consistent increase in SOD activity. Aerobic exercise enhanced activities of CAT and GSH-Px and promoted MDA scavenging. Results suggested that exercise can accelerate adaptive responses to oxidative stress and activate antioxidant enzymes activities. Exercise can also facilitate the reduction of DDT-induced oxidative damage and promoted DDT degradation. This study strongly implicated the positive effect of exercise training on DDT-induced liver oxidative stress.

Total dissolved gas (TDG) supersaturation downstream has a negative environmental effect on fishes. It is caused by discharge from high dams and increases the incidence of gas bubble disease and fish mortality. Downstream of a high dam, there is an area with low TDG saturation due to the gradual mass exchange of gases between the separation zone and the mainstream and the long retention time in the confluence, which contributes to the dissipation of saturated TDG at the confluence of the mainstream and its tributaries. This area can provide a temporary shelter for fish to avoid the effects of TDG supersaturation during dam discharge. A depth-averaged, two-dimensional model of TDG dissipation at a river confluence was established. The concentration field was verified by a flume experiment. A numerical simulation of the TDG at the confluence of the Zumuzu River and its tributary, the Mozigou River, was conducted. The simulation showed that the convergence of the tributary, which had a low TDG saturation level, could reduce the TDG saturation level of the mainstream. However, the low-saturation area was not large enough for fish to avoid the negative effects of TDG saturation due to a sharp river slope and a large flow ratio between the mainstream and its tributary. To expand the suitable shelter area with low TDG supersaturation levels in order to provide a suitable shelter for fish, some engineering measures were explored, including the excavation of the riverbed and the construction of resistance obstacles. After the engineering measures were introduced, we observed a 30-fold increase in the size of the area with low TDG saturation, which was as high as 10005 m2 at 110% of the TDG saturation. Combined with the comprehensive analyses of the flow velocity and the water depth, the confluence region was thought to be suitable to protect the fish from the effects of TDG supersaturation. This study provides an important reference for protecting fish during high dam discharge.

Schizothorax prenanti ( S. prenanti ) is a second-class provincial protected endemic fish within the upper reaches of the Min River. The spawning season of S. prenanti extends from March to April. Habitat alteration and the construction of multistage dams have resulted in a rapid decline of the S. prenanti population. To assess the potential effects of a reduced flow volume on the S. prenanti spawning habitat area in downstream of dams, we combined River 2D and a habitat similarity evaluation model through the following steps. First, we conducted surveys of S. prenanti and the substrate composition in a natural habitat reach and a hydropower-affected reach. Second, hydraulic simulations were performed over a range of flows using River 2D. Third, vague sets of habitat variables were individually defined based on multi-expert opinions. Fourth, we estimated the weighted similarity of the S. prenanti spawning habitat using input variables (water depth, velocity) from River 2D. Fifth, we verified the model with S. prenanti survey data. Hydraulic simulations for velocity and depth yielded accuracies of approximately 84–97% and 81–98%, respectively. The weighted similarity simulations showed that weighted similarity increased with the flow up to a threshold range of approximately 130–150 m 3 /s; beyond this range, the weighted similarity decreased. The weighted similarity in the natural habitat reach was higher than in the restored reach at the same flow volume due to geography. The habitat similarity model provides restoration targets and thresholds for decision makers to develop a proactive conservation strategy for wetland management.

Dam discharges over spillways are the main reason for the gas-supersaturated water generated in rivers. Local aquatic organisms, especially fish, readily develop gas bubble disease (GBD) in a river with total dissolved gas supersaturation (TDGS). Sometimes, fish will die after a specific exposure period, which negatively affects the biological equilibrium. In this study, the influence of TDGS on silver carp was explored. Silver carp were exposed to gas-supersaturated water with TDGS levels of 140%, 135%, 130%, 125%, 120%, and 110% to test the impact of TDGS. Some silver carp died when the TDGS level was 120% or higher, and all the silver carp exposed to a TDGS level of 140% died within 10 h. In comparison with the Chinese sucker, Prenant's schizothoracin, and rock carp, silver carp seem less sensitive to TDGS. In addition, we tested the catalase (CAT) activity in the muscles and gills of silver carp after they were exposed to gas-supersaturated water with a TDGS level of 140%. The CAT activity changed with time; it increased first and then decreased until it was lower than the initial CAT activity. The results of this study can provide basic data for developing a standard for environmental evaluation.

The spectroscopic properties of 2-μm emission in Ho 3+ -doped lanthanum–tungsten–tellurite glasses with different Ho 2 O 3 concentrations were investigated. The strongest emission was observed in a glass sample doped with 0.5 mol% Ho 2 O 3 , with a fluorescence lifetime of 3.16 ms and a emission cross section of 6.97×10 −21 cm 2 at 2040 nm. For this composition, no obvious changes in the emission properties and fluorescence lifetime were observed at temperatures of 295–350 K. Using this 60TeO 2 –30WO 3 –9.5La 2 O 3 –0.5Ho 2 O 3 glass as a core material, Ho 3+ -doped double cladding fiber with a core diameter of 14 μm and a numerical aperture of 0.12 was developed. A maximum laser output power of 34 mW at 2040 nm was achieved with a 9-cm-long Ho 3+ -doped tellurite glass fiber. To the best of our knowledge, this study presents the first report on the 2-μm laser output from a Ho 3+ -doped tellurite oxide glass fiber resonantly pumped by a 1.94 μm Tm-fiber laser.

This paper aims to systematically investigate the impacts of hybrid fibers on properties of high strength fiber-reinforced self-consolidating concrete (FRSCC). In total, nine mixtures with different fiber types (Polyvinyl Alcohol/PVA, and hybrid fibers) and fiber factors (λ = 0 ~ 70) were fabricated with same basic mix proportioning. Workability tests include slump flow, T50 time, and J-ring tests were carried out to quantify the effects of fiber factor. The compressive strength, four-point bending tests, drying shrinkage, and compressive creep tests were performed on hardened concrete to reveal the intrinsic effects of single/hybrid fibers. Finally, a hyperbolic drying shrinkage prediction model with fiber factor was proposed. Experiment results indicated that single PVA fibers displayed identical influences on slump flow as steel fiber with similar fiber factor, however, can result in higher viscosity. Meanwhile, PVA fibers reduced the compressive strength and displayed limited restraining effects on the specific creep. However, the positive synergetic effects of hybrid fibers can reverse the reductions in compressive strength caused by the PVA fiber and increase flexural performances with multi-scale bridge effects. Moreover, hybrid fibers are more effective in inhibiting the time-dependent strains of FRSCC, followed by steel fiber and synthetic PVA fiber. The proposed hyperbolic drying shrinkage model is capable of predicting the drying shrinkage of FRSCC with a suitable shrinkage halftime.

Hydropower, which utilizes energy from fast-moving water, can help alleviate the energy crisis and promote economic development. For safety and ecological purposes, dams must discharge periodically. This discharge process, which occurs with the supersaturation of total dissolved gas (TDG), affects the fish and other aquatic organisms living in downstream river areas. Previous studies have shown that the supersaturated TDG dissipation process is closely related to hydraulic properties such as the flow rate, water depth and turbulent kinetic energy. Additionally, the presence of solid walls such as vegetation leaves in water can adsorb dissolved gases in water, thereby promoting the supersaturated TDG dissipation process, and the adsorption effect is closely related to the solid wall material. However, systematic studies on how solid walls in water can quickly absorb dissolved gases from water and rapidly reduce the TDG saturation of water are lacking. Herein, a series of experiments was conducted to study the dissipation process of supersaturated TDG under the action of solid walls in water and to reveal the adsorption effect of solid wall surface properties on dissolved gas. The results showed that the surface roughness and hydrophobicity (contact angle) are the key factors related to the adsorption effect of solid walls on the TDG in water. Generally, the dissipation rate of supersaturated TDG first increased and then decreased with increasing surface roughness. The supersaturated TDG dissipation rate increased monotonically with increasing contact angle. Based on the experimental data, the adsorption coefficient, which represents the adsorption effect of the solid wall for dissolved gas in water, was proposed, and a prediction formula between the adsorption coefficient and the contact angle of the solid wall was established. These results can provide theoretical support for the utilization of the solid wall adsorption effect to mitigate the adverse effects of supersaturated TDG and protect fish.

The mechanical properties of high-entropy alloys (HEAs) strongly depend on their microstructural features. In this work, the phase formation and morphologies of Fe26.7Co26.7Ni26.7Si8.9B11.0 HEAs fabricated under different undercooling levels by the drop tube technique together with subsequent quenching were investigated in detail. It was found when the droplet size decreases (i.e. the increase of the undercooling level), the grain refinement is easily achieved without any phase transformation for the present hypoeutectic HEA which is composed of the fcc dendrites and eutectic structure. After quenching under large undercooling levels, the liquid should be deeply undercooled into an asymmetric couple zone, leading to the primary formation of eutectic structure and the subsequent precipitation of the fcc dendrites. The direct product of rapid solidification after deep undercooling and subsequent recalescence may induce the decoupled eutectic growth, resulting in a transition from the regular into anomalous eutectic structures. Furthermore, the volume fractions of the eutectic structures and the fcc dendrites increase and decrease with decreasing droplet size, respectively. As a result, the Vickers hardness gradually increases with decreasing droplet size, which exhibits a linear relationship with the volume fraction of eutectic matrix. The present study may provide a simple way to tailor microstructures and mechanical properties of HEAs.

Selective laser melting of ductile Cu particles reinforced Fe-based bulk metallic glass composites (Fe-based BMGCs) were used to break geometric complexity limitations and improve the mechanical properties. In this work, the effects of Cu content on microstructure, mechanical properties and fracture deformation behavior of Fe-based BMCGs were systematically investigated. The appropriate Cu addition can decrease stress concentration by altering elements distribution, especially C element which will increase the brittleness of BMGs and lead to crack formation. The crack-free Fe-based BMGCs with a well bonding interface between the secondary phase and matrix is presented with 40 vol.% Cu addition. The improved plasticity of BMGCs with Cu addition originates from the inhibition of shear bands via formation of multiple shear bands. This work demonstrates that introducing tough secondary phase into BMGs is an effective method to improve their formability and performance.

The swimming abilities of Spinibarbus hollandi, Siniperca chuatsi, Siniperca loona, Odontobutis sinensis and Rhinogobius giurinus were tested in this study, including induced swimming speed (Uind), critical swimming speed (Ucrit) and constant acceleration test speed (UCAT). The results showed that the Uind of the experimental fish in the Huishui River ranged from 5 to 30 cm/s. The average Ucrit of fish was 68.2 cm/s and 5 times the average Uind. The average UCAT was 97.6 cm/s and 7 times the Uind. The swimming speed of fish is related to their body size. The results showed that the swimming speed was more correlated with the shape than the body length of fish. The relationships between the three speeds and the shape of the experimental fish were U ind = 9.809 S 0.128 U crit = 37.954 S 0.185 , and U CAT = 58.418 S 0.099 . The differences in Uind between the five fishes were not obvious, while there were significant differences in Ucrit and UCAT between the five fish species. The results of this study suggested that Spinibarbus hollandi, Siniperca chuatsi, and Siniperca loona have stronger swimming abilities than Odontobutis sinensis and Rhinogobius giurinus.

Co–Cr based alloys are recognized as one of the most widely used category of alloys amongst the biomedical materials. This is because these alloys show a high strength, corrosion resistance and good biocompatibility suitable for biomedical applications. Many researchers have been focused on the processing of these alloys using a selective laser melting process. The effects of different processing parameters on the obtained microstructural and mechanical properties of the processed parts have been investigated in these studies. However, the effect of powder distribution size (powder granulometry), as a primary processing parameter, on the microstructural and mechanical properties of Co–Cr alloys is not well investigated and studied so far. This study investigated the influence of this parameter, by using powders with the same composition and morphology but a different particle size of coarse and fine, on the microstructural and mechanical properties of as-built, homogenizing heat treated and homogenizing heat treated followed by subsequent aging treatment SLM fabricated Co28Cr9W1.5Si (wt.%) samples. X-ray diffraction, scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy were used to characterize and identify the microstructure, phase composition and crystallographic information of the manufactured samples. Besides, the mechanical properties of samples, processed using powders having different size distributions, were measured using a tensile test machine and results were correlated to the microstructure of the samples. It was concluded that the powder granulometry has a negligible effect on the microstructural and mechanical properties of the as-built SLM Co–Cr–W–Si parts but a remarkable influence on those of the heat-treated ones.

Ho2O3-doped transparent tellurite glass–ceramics containing a metastable cubic crystalline phase were prepared. The structure, mechanical properties, 2-μm fluorescence, and decay times of the glass and glass–ceramics were investigated. The Judd–Ofelt intensity parameters, spontaneous radiative probability, and absorption and stimulated-emission cross-sections were calculated. After crystallization, the tellurium coordination number increased (3/3 + 1 → 4), which indicates that the structure changed substantially. The density, refractive index, and Knoop hardness of the glass–ceramics were enhanced compared with those of the precursor glass. After heat treatment, the spontaneous radiative probability and maximum stimulated emission cross-section increased to 172.24 s−1 and 0.744 × 10−20 cm2, respectively. Moreover, the 2-μm emission intensity of the glass–ceramic increased threefold under excitation by a 640-nm laser diode. The lifetime of the Ho3+:5I7 level in the transparent glass–ceramic was longer than that of precursor glass. The split in the absorption and emission bands and the reduction of the Ω2 parameter for the glass–ceramic confirmed the incorporation of Ho3+ ions into the crystalline phase. The results indicate that TeO2-based glass–ceramics are a promising candidate material for 2-μm lasers.