To evaluate the status of the eco-health of Bahe River in recent years and seek for a rational and ecological way of development and utilization,this study integrates such factors as hydrology,river morphology,water quality,habitat environ to construct the evaluation index system of river health,and divides the corresponding evaluation grade standard.The extension matter-element evaluation model is established in the perspective of entropy and the dynamic evaluation is made of ecological health of Bahe River as combined with the changes in time series of each index.The comprehensive evaluation results show that Bahe River health levels in the years of2006—2012were health,sub-health,sub-health,general,sub health,sub-health,and general respectively being basically same to the results of AHP.The correlation degree calculation and evaluation results of single index show that the exploitation and utilization of surface water are always in an appropriate range.The wetland retention rate and the river habitat status gradually are growing.The buried depth of groundwater is always at a lower level,where by making the river be in a poor state of health.The vertical connectivity of river gradually becomes worse.Therefore,the development and utilization of resources and functions must be done with the goal of the ecological health of the river so as to achieve harmonious and ecological operation.
This paper reports the results of an experimental study testing a low-cost in situ chemical fixation method designed to reclaim arsenic-contaminated subsurface soils. Subsurface soils from several industrial sites in southeastern U.S. were contaminated with arsenic through heavy application of herbicide containing arsenic trioxide. The mean concentrations of environmentally available arsenic in soils collected from the two study sites, FW and BH, are 325 mg/kg and 900 mg/kg, respectively. The soils are sandy loams with varying mineralogical and organic contents. The previous study [Yang L, Donahoe RJ. The form, distribution and mobility of arsenic in soils contaminated by arsenic trioxide, at sites in Southeast USA. Appl Geochem 2007;22:320 341] indicated that a large portion of the arsenic in both soils is associated with amorphous aluminum and iron oxyhydroxides and shows very slow release against leaching by synthetic precipitation. The soil's amorphous aluminum and iron oxyhydroxides content was found to have the most significant effect on its ability to retain arsenic.Based on this observation, contaminated soils were reacted with different treatment solutions in an effort to promote the formation of insoluble arsenic-bearing phases and thereby decrease the leachability of arsenic. Ferrous sulfate, potassium permanganate and calcium carbonate were used as the reagents for the chemical fixation solutions evaluated in three sets of batch experiments: (1) FeSO4; (2) FeSO4 and KMnO4; (3) FeSO4, KMnO4 and CaCO3. The optimum treatment solutions for each soil were identified based on the mobility of arsenic during sequential leaching of treated and untreated soils using the fluids described in EPA Method 1311 [USEPA. Method 1311: toxicity characteristic leaching procedure. Test methods for evaluating solid waste, physical/chemical methods. 3rd ed. Washington, DC: U.S. Environmental Protection Agency, Office of Solid Waste. U.S. Government Printing Office; 1992] toxic characteristics leaching procedure (TCLP) and EPA Method 1312 [USEPA. Method 1312: synthetic precipitation leaching procedure. Test methods for evaluating solid waste, physical/chemical methods. 3rd ed. Washington, DC: U.S. Environmental Protection Agency, Office of Solid Waste. U.S. Government Printing Office; 1994] synthetic precipitation leaching procedure (SPLP).Both FW and BH soils showed significant decreases in arsenic leachability for all three treatment solutions, compared to untreated soil. While soils treated with solution (3) showed the best results with subsequent TCLP sequential leaching, SPLP sequential leaching of treated soils indicated that lowest arsenic mobility was obtained using treatment solution (1). Treatment solution (1) with only FeSO4 is considered the best choice for remediation of arsenic-contaminated soil because SPLP sequential leaching better simulates natural weathering. Analysis of treated soils produced no evidence of newly-formed arsenic-bearing phases in either soil after treatment. Sequential chemical extractions of treated soils indicate that surface complexation of arsenic on ferric hydroxide is the major mechanism for the fixation process.
Global warming presents an unprecedented challenge to our planet however comprehensive understanding remains hindered by geographical biases temporal limitations and lack of standardization in existing research. An end to end visual analysis of global warming using three distinct temperature datasets is presented. A baseline adjusted from the Paris Agreements one point five degrees Celsius benchmark based on data analysis is employed. A closed loop design from visualization to prediction and clustering is created using classic models tailored to the characteristics of the data. This approach reduces complexity and eliminates the need for advanced feature engineering. A lightweight convolutional neural network and long short term memory model specifically designed for global temperature change is proposed achieving exceptional accuracy in long term forecasting with a mean squared error of three times ten to the power of negative six and an R squared value of zero point nine nine nine nine. Dynamic time warping and KMeans clustering elucidate national level temperature anomalies and carbon emission patterns. This comprehensive method reveals intricate spatiotemporal characteristics of global temperature variations and provides warming trend attribution. The findings offer new insights into climate change dynamics demonstrating that simplicity and precision can coexist in environmental analysis.
Mounting behaviour is an important characteristic of cows during oestrus. Real-time and accurate detection of cow mounting behaviour can shorten the calving-to-conception period and increase the economic benefits for dairy farms. Cow mounting behaviour occurs more often at night, and drastic scale changes in surveillance images caused by different distances between cows and camera, influence the detection of cow mounting. Existing methods are unable to address these challenges effectively. To address these challenges, this study collected 9392 images of Holstein cow mounting behaviour under intensive farming conditions using cameras and proposed an IATEFF-YOLO that is more suitable for cow mounting behaviour detection at nighttime and drastic scale changes in surveillance images caused by different distances between cows and camera. IATEFF-YOLO comprises an Illumination Adaptive Transformer (IAT) and an efficient feature fusion detector. The IAT enhances low-light images at night to enrich the cow mounting features, facilitating the subsequent detection of mounting behaviour. The efficient feature fusion detector, EFF-YOLO, enhances the feature fusion capability and further enable the detector to adapt to drastic scale changes in surveillance images caused by different distances between cows and camera. IATEFF-YOLO achieved a mean Average Precision of 99.3% and a detection speed of 102.0 f/s on test set. Compared with existing methods, IATEFF-YOLO achieved higher detection accuracy and faster detection speed during nighttime and drastic scale changes in surveillance images caused by different distances between cows and camera. IATEFF-YOLO can assist ranch breeders in achieving round-the-clock monitoring of cow oestrus, thereby enhancing oestrus detection efficiency.
The demand for spatial infrared remote sensors with high spatial resolution and wide imaging swatch becomes more and more urgent. Optical system is an important constraint on the performance of spatial infrared remote sensors. In this paper, a novel off-axis catadioptric optical system configuration with intermediate image is proposed. The imaging principle and the initial configuration solution method are analyzed. And an off-axis catadioptric freeform optical system is designed with the spectrum of 7.8-10.2μm, the aperture of 435 mm, the focal length of 1038 mm, and the field of view (FOV) of 9×1.1°. The modulation transfer function (MTF) value is better than 0.316@25lp/mm. The maximum relative distortion is -0.27%. And this optical system has good image-side telecentricity and image illumination consistency. The results show that the spatial infrared off-axis catadioptric freeform optical system has good imaging quality and engineering feasibility.
Geological sequestration is one of the most effective ways to reduce greenhouse gases, such as carbon dioxide (CO2). The deep oceanic crust dominated by ultrabasic rock could store CO2 permanently. However, the storage mechanism has not been thoroughly understood because of the limited amount of research and experiments conducted. This study explored the reactive mechanisms of water–rock–gas in an ultrabasic system under different conditions. Forsterite, the most dominant mineral found in ultrabasic reservoirs, was used to conduct laboratory physical simulation experiments. Two experimental systems were designed including an scCO2–forsterite–water system and an N2–forsterite–water system. All experiments were performed for 1000 h at an experimental temperature of 150°C and a pressure of 150 bar, respectively, to mimic the geological conditions. The liquid products from the experiments were analysed by inductively coupled plasma-optical emission spectrometry, whereas the solid samples were analysed by scanning electron microscopy with energy disperse spectroscopy. Results showed that: (1) in the early stage during scCO2/N2–forsterite–water interaction, forsterite was dissolved with a reactive transitional zone forming on the surface, which caused H+ to enter into the silicate framework and accelerated the reaction; (2) in the N2 system, the dissolution of forsterite was inhibited by the Mg2+ concentration after reaching its saturation in the late stage; and (3) in the scCO2 system, magnesite was precipitated as a secondary mineral during the late stage, which promoted the dissolution of forsterite. As a result, the degree of dissolution of forsterite in the scCO2 system was far higher than in the N2 system. The experimental results are consistent with the numerical simulation using TOUGHREACT, a geochemical simulation procedure, which showed that CO2 promotes the dissolution of forsterite greatly at high temperature and pressure.
The color reaction of mercury with p \|sulfobenzylidene\|rhodanine(SBDR) was studied.In the presence of pH=4.0 HAc\|NaAc solution,SBDR can react with mercury (Ⅱ) to form a stable 2∶1 complex.The molar absorptivity is 8.16×10 4L·mol -1 ·cm -1 at 510nm.Beer's law is obeyed in the range of 0_30μg/25mL.This method was applied to the determination of mercury in water with satisfactory results.
Recently, various environmental problems have been generated with the rapid economic development in China. That's because China currently over-emphasized economic development beyond environmental issues; therefore, now it is important to enforce optimal environmental policies in order to achieve economic development as well as environmental improvement. In this study, we selected Jiaxing city as research area for that the environmental pollution problem has become prominent with economic high growth, and we constructed environmental system model and social economic model to establish the scenarios. Through computer simulation, we can evaluate the efficiency of the comprehensive environmental policies from both environmental preservation and social economic development aspects. While the social-economic model shows the socioeconomic activities which are vital events, fortune and service, such as production, finance and budget; the environmental system model shows the water pollutants and the greenhouse gas movement in the region. The dynamic optimization simulation is accomplished based on this environmental and socio-economic system model. In view of the restriction on water pollutants, greenhouse gas total exhausted amount, and economic activity in the catchment area, the simulation we practiced can provide concrete inner-generating optimal policies which can achieve the best economic and environment improvement with the consideration of policy, regional and timing choice in Jiaxing City, China.
DMSP/OLS i is a special night-time imageries source that offers capabilities to represent human activities on the Earth's surface through the observation of artificial lighting at night. This paper analyses CNLI ii of the earth at night derived from the DMSP-OLS night-time lights data, and it reveals striking correlations between CNLI and greenhouse gases emissions. The objective of this paper is to predict and model the relationships between the CNLI and trends of greenhouse gases emissions from 1996 to 2013, through comparative types of night-time lights time series, correlation matrix, forecast R value, regression models and eventually time series modelling.
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