Catalytic nickel was successfully incorporated into nanoscale iron to enhance its dechlorination efficiency for trichloroethylene （TCE）, one of the most commonly detected chlorinated organic compounds in groundwater...Catalytic nickel was successfully incorporated into nanoscale iron to enhance its dechlorination efficiency for trichloroethylene （TCE）, one of the most commonly detected chlorinated organic compounds in groundwater. Ethane was the predominant product. The greatest dechlorination efficiency was achieved at 22 molar percent of nickel. This nanoscale Ni-Fe is poorly ordered and inhomogeneous; iron dissolution occurred whereas nickel was relatively stable during the 24-hr reaction. The morphological characterization provided significant new insights on the mechanism of catalytic hydrodcchlorination by bimetallic nanoparticles. TCE degradation and ethane production rates were greatly affected by environmental parameters such as solution pH, temperature and common groundwater ions. Both rate constants decreased and then increased over the pH range of 6.5 to 8.0, with the minimum value occurring at pH 7.5. TCE degradation rate constant showed an increasing trend over the temperature range of 10 to 25℃. However, ethane production rate constant increased and then decreased over the range, with the maximum value occurring at 20℃, Most salts in the solution appeared to enhance the reaction in the first half hour but overall they displayed an inhibitory effect. Combined ions showed a similar effect as individual salts.展开更多
Accurately predicting environmental parameters in solar greenhouses is crucial for achieving precise environmental control.In solar greenhouses,temperature,humidity,and light intensity are crucial environmental parame...Accurately predicting environmental parameters in solar greenhouses is crucial for achieving precise environmental control.In solar greenhouses,temperature,humidity,and light intensity are crucial environmental parameters.The monitoring platform collected data on the internal environment of the solar greenhouse for one year,including temperature,humidity,and light intensity.Additionally,meteorological data,comprising outdoor temperature,outdoor humidity,and outdoor light intensity,was gathered during the same time frame.The characteristics and interrelationships among these parameters were investigated by a thorough analysis.The analysis revealed that environmental parameters in solar greenhouses displayed characteristics such as temporal variability,non-linearity,and periodicity.These parameters exhibited complex coupling relationships.Notably,these characteristics and coupling relationships exhibited pronounced seasonal variations.The multi-parameter multi-step prediction model for solar greenhouse(MPMS-SGH)was introduced,aiming to accurately predict three key greenhouse environmental parameters,and the model had certain seasonal adaptability.MPMS-SGH was structured with multiple layers,including an input layer,a preprocessing layer,a feature extraction layer,and a prediction layer.The input layer was used to generate the original sequence matrix,which included indoor temperature,indoor humidity,indoor light intensity,as well as outdoor temperature and outdoor light intensity.Then the preprocessing layer normalized,decomposed,and positionally encoded the original sequence matrix.In the feature extraction layer,the time attention mechanism and frequency attention mechanism were used to extract features from the trend component and the seasonal component,respectively.Finally,the prediction layer used a multi-layer perceptron to perform multi-step prediction of indoor environmental parameters(i.e.temperature,humidity,and light intensity).The parameter selection experiment evaluated the predictive performance of MPMS-SGH on input and output sequences of different lengths.The results indicated that with a constant output sequence length,the prediction accuracy of MPMS-SGH was firstly increased and then decreased with the increase of input sequence length.Specifically,when the input sequence length was 100,MPMS-SGH had the highest prediction accuracy,with RMSE of 0.22℃,0.28%,and 250lx for temperature,humidity,and light intensity,respectively.When the length of the input sequence remained constant,as the length of the output sequence increased,the accuracy of the model in predicting the three environmental parameters was continuously decreased.When the length of the output sequence exceeded 45,the prediction accuracy of MPMS-SGH was significantly decreased.In order to achieve the best balance between model size and performance,the input sequence length of MPMS-SGH was set to be 100,while the output sequence length was set to be 35.To assess MPMS-SGH’s performance,comparative experiments with four prediction models were conducted:SVR,STL-SVR,LSTM,and STL-LSTM.The results demonstrated that MPMS-SGH surpassed all other models,achieving RMSE of 0.15℃for temperature,0.38%for humidity,and 260lx for light intensity.Additionally,sequence decomposition can contribute to enhancing MPMS-SGH’s prediction performance.To further evaluate MPMS-SGH’s capabilities,its prediction accuracy was tested across different seasons for greenhouse environmental parameters.MPMS-SGH had the highest accuracy in predicting indoor temperature and the lowest accuracy in predicting humidity.And the accuracy of MPMS-SGH in predicting environmental parameters of the solar greenhouse fluctuated with seasons.MPMS-SGH had the highest accuracy in predicting the temperature inside the greenhouse on sunny days in spring(R^(2)=0.91),the highest accuracy in predicting the humidity inside the greenhouse on sunny days in winter(R^(2)=0.83),and the highest accuracy in predicting the light intensity inside the greenhouse on cloudy days in autumm(R^(2)=0.89).MPMS-SGH had the lowest accuracy in predicting three environmental parameters in a sunny summer greenhouse.展开更多
Forecasting environmental parameters in the distant future requires complex modelling and large computational resources.Due to the sensitivity and complexity of forecast models,long-term parameter forecasts(e.g.up to ...Forecasting environmental parameters in the distant future requires complex modelling and large computational resources.Due to the sensitivity and complexity of forecast models,long-term parameter forecasts(e.g.up to 2100)are uncommon and only produced by a few organisations,in heterogeneous formats and based on different assumptions of greenhouse gases emissions.However,data mining techniques can be used to coerce the data to a uniform time and spatial representation,which facilitates their use in many applications.In this paper,streams of big data coming from AquaMaps and NASA collections of 126 long-term forecasts of nine types of environmental parameters are processed through a cloud computing platform in order to(i)standardise and harmonise the data representations,(ii)produce intermediate scenarios and new informative parameters,and(iii)align all sets on a common time and spatial resolution.Time series crosscorrelation applied to these aligned datasets reveals patterns of climate change and similarities between parameter trends in 10 marine areas.Our results highlight that(i)the Mediterranean Sea may have a standalone‘response’to climate change with respect to other areas,(ii)the Poles are most representative of global forecasted change,and(iii)the trends are generally alarming for most oceans.展开更多
Air distribution of HVAC systems is the most popular type used in the building sector,having a relevant impact on indoor air quality and occupant wellness.Many types of research developed optimal solutions for the HVA...Air distribution of HVAC systems is the most popular type used in the building sector,having a relevant impact on indoor air quality and occupant wellness.Many types of research developed optimal solutions for the HVAC system’s design,focusing on specific components of the distribution system,on the airflow and geometry of ducts,on the size of ducts,on the shape and position of air diffusers.However,few works in literature proposed a globally experimental and simulation analysis of an air distribution system with a variable mass flaw rate.Along this line,the presented research investigates the potentialities of a new ceiling diffuser,installed in an exhibition room.This system provides a variable mass flow rate thanks to its configuration,providing adequate thermal comfort.A warm wall is chosen as the heating system.Several tests are carried out,six for cooling and two for heating with different volumetric air rates and supply air temperature of the diffusers.The combination of two methods,the measurement campaigns and the computational fluid dynamics(CFD)technique represent a suitable approach to examine the thermal indoor environment.In general,results show a strong capability of this diffuser to provide a uniform temperature and velocity field inside the room.Moreover,experimental and numerical data are significantly comparable with an average deviation of 1%for the velocity and lower 1%for the temperature,guaranteeing an optimal distribution of the understudy environmental parameters on the vertical and horizontal planes.展开更多
The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainti...The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainties in the calculation of marine environmental design parameters,a general model uncertainty assessment method is necessary.We proposed a new multivariate model uncertainty assessment method for the calculation of marine environmental design parameters.The method divides the overall model uncertainty into two categories:aleatory uncertainty and epistemic uncertainty.The aleatory uncertainty of the model is obtained by analyzing the influence of the number and the dispersion degree of samples on the information entropy of the model.The epistemic uncertainty of the model is calculated using the information entropy of the model itself and the prediction error.The advantages of this method are that it does not require many-year-observation data for the marine environmental elements,and the method can be used to analyze any specific factors that cause model uncertainty.Results show that by applying the method to the South China Sea,the aleatory uncertainty of the model increases with the number of samples and then stabilizes.A positive correlation was revealed between the dispersion of the samples and the aleatory uncertainty of the model.Both the distribution of the model and the parameter estimation results of the model have significant effects on the epistemic uncertainty of the model.When the goodness-of-fit of the model is relatively close,the best model can be selected according to the criterion of the lowest overall uncertainty of the models,which can both ensure a better model fit and avoid too much uncertainty in the model calculation results.The presented multivariate model uncertainty assessment method provides a criterion to measure the advantages and disadvantages of the marine environmental design parameter calculation model from the aspect of uncertainty,which is of great significance to analyze the uncertainties in the calculation of marine environmental design parameters and improve the accuracy of the calculation results.展开更多
In this article the corrosion rate of the austenitic stainless steel type 304, under the synergistic effect of environmental factors has been assessed via potentiodynamic polarization scan.Salinity, velocity, pH and t...In this article the corrosion rate of the austenitic stainless steel type 304, under the synergistic effect of environmental factors has been assessed via potentiodynamic polarization scan.Salinity, velocity, pH and temperature are the factors which induce effects on the corrosion rate of the considered metal.Quantitative analysis is applied using the full two-level factorial experimental design method, which results in the contribution value of each parameter in changing the quantity of average corrosion rate in both individual and synergistic cases.Besides this quantitative analysis, qualitative analysis has been used to predict the variation direction.These two analyses show the important role of the synergistic action, which changes the variation direction of corrosion rate and the contribution percentage of each parameter in varying the value of corrosion rate.Applying both these analyses can show the magnitude and quality of each parameter＇s effect, which is remarkably valuable in marine applications.展开更多
Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issue...Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.展开更多
In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production...In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production and security conditions. The client computer can convert the analog signal about the safety in production and environmental parameters detected from the monitoring terminal into digital signal,and then,send the signal to the coal mine safety monitoring centre. This information can be analyzed,judged,and diagnosed by the monitoring-management-controlling software for helping the manager and technical workers to control the actual underground production and security situations. The system has many advantages including high reliability,better performance of real-time monitoring,faster data communicating and good practicability,and it can effectively prevent the occurrence of safety incidents in coal mines.展开更多
The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the π-pulse sequences(both equidistan...The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the π-pulse sequences(both equidistant and optimized)to a quantum probe coupled to a bosonic environment. To demonstrate the precision of cutoff frequency estimation, we theoretically derive the quantum Fisher information(QFI) and quantum signal-to-noise ratio(QSNR) across sub-Ohmic,Ohmic, and super-Ohmic environments, and investigate their behaviors through numerical examples. The results indicate that, compared to the equidistant π-pulse sequence, the optimized π-pulse sequence significantly shortens the time to reach maximum QFI while enhancing the precision of cutoff frequency estimation, particularly in deep sub-Ohmic and deep super-Ohmic environments.展开更多
Soil CO<sub>2</sub> efflux is an ongoing process of respiration from soil;plant parts/ microbes below the ground to the atmosphere which is known for faster cycling of carbon sources. A large portion of ca...Soil CO<sub>2</sub> efflux is an ongoing process of respiration from soil;plant parts/ microbes below the ground to the atmosphere which is known for faster cycling of carbon sources. A large portion of carbon sequestered and fixed by forests is returned to the atmosphere through soil CO<sub>2</sub> efflux and multiple controlling parameters mainly temperature, precipitation, and growth factors interact with the soil CO<sub>2</sub> efflux variation. This study assessed the soil CO<sub>2</sub> efflux every month for consecutive 2-years (August 2015 to July 2017) by using the closed chamber method to determine the role of ecological parameters that govern the soil CO<sub>2</sub> efflux and its temporal modification in a sub-tropical mixed forest of central region in Nepal. The results of this study manifested that soil CO<sub>2</sub> efflux accounted 63.2% (y = 31.96e<sup>0.128x</sup>), 71.3% (y = 44.77e<sup>0.123x</sup>) and 64.5% (y = 44.11e<sup>0.117x</sup>) variations in soil temperature with significantly (p < 0.05) exponential positive relation in the year 2015/2016, 2016/2017 and the two years when merged. And the temperature sensitivity value (Q<sub>10</sub>) of the soil CO<sub>2</sub> efflux was 3.6, 3.4, and 3.2, respectively. Soil water content also expressed significantly (p < 0.05) positive exponential effect on soil CO<sub>2</sub> efflux and accounted 62.0% (y = 138.3e<sup>0.057x</sup>), 46.1% (y = 88.42e<sup>0.052x</sup>) and 40.5% (y = 133.1e<sup>0.0447x</sup>) in its variability in different years and the merged years. Evident variations of soil CO<sub>2</sub> efflux, soil temperature, soil water content, and litter were observed in the forest seasonally and inter-annually. Two years mean total annual soil CO<sub>2</sub> efflux of the forest was estimated at 904.76 g C·m<sup>-2</sup>·y<sup>-1</sup>. The study revealed that sub-tropical forests could be more influenced by precipitation regimes in progressing warm climates i.e. vulnerable to climate change, illustrating the comprehensive dynamics of the representative forest carbon cycle in the tropical region.展开更多
An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of tempera...An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at May 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.展开更多
An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of tempera...An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at May 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.展开更多
The manual selection of environment parameters during welding simulation will bring a significant error to the simulation result of welding temperature field. By a combination of finite element method （FEM） and infr...The manual selection of environment parameters during welding simulation will bring a significant error to the simulation result of welding temperature field. By a combination of finite element method （FEM） and infrared thermography, these environment parameters were inversed mathematically in place of previous manual selection. First, FEM model of the welding process was constructed, and the temperature field was computed with initial environment parameters. Then, a real welding process was conducted and the temperature field was measured by infrared thermography. Last, the simulation and measurement results were compared, and the environment parameters were adjusted continuously with the genetic algorithm （ GA ） until the simulation matched the measurement best. Parameters according to the best-matched simulation results were considered as the most appropriate parameters.展开更多
Composite radar reflectivity data during April-September 2011-2015 are used to investigate and classify storms in south China(18-27°N;105-120°E). The storms appear most frequently in May. They are either lin...Composite radar reflectivity data during April-September 2011-2015 are used to investigate and classify storms in south China(18-27°N;105-120°E). The storms appear most frequently in May. They are either linear;cellular or nonlinear systems, taking up 29.45%, 24.51% and 46.04%, respectively, in terms of morphology. Linear systems are subdivided into six morphologies: trailing stratiform precipitation(TS), bow echoes(BE), leading stratiform precipitation(LS), embedded line(EL), no stratiform precipitation(NS) and parallel stratiform precipitation(PS). The TS and NS modes have the highest frequencies but there are only small samples of LS(0.61%) and PS(0.79%) modes.Severe convective wind(≥17m s-1at surface level) accounts for the highest percentage(35%) of severe convective weather events produced by cellular systems including individual cells(IC) and clusters of cells(CC). Short-duration heavy rainfall(≥50 mm h-1) and severe convective wind are the most common severe weather associated with TS and BE modes. Comparison of environmental physical parameters shows that cellular convection systems tend to occur in the environment with favorable thermal condition, substantial unstable energy and low precipitable water from the surface to300 hPa(PWAT). However, the environmental conditions favoring the initiation of linear systems feature strong vertical wind shear, high PWAT, and intense convective inhibition. The environmental parameters favoring the initiation of nonlinear systems are between those of the other two types of morphology.展开更多
The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to healt...The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to health and welfare of animals in industrial farms with intensive husbandry. Health, management, environmental and productive parameters were firstly characterized and then a protocol to assess welfare of rabbits was define. The research was conducted on 8 industrial farms from 2004 to 2007 and around 30 inspections were done in each farm. At each visit, the health conditions were established by： （1） necropsy on animals of different productive category; （2） specific laboratory investigations based on the lesions observed; （3） checking the presence of parasites in environmental faecal samples; （4） bacteriological examination of vaginal, nasal and rectal swabs of rabbit of different age. The immune conditions and the efficacy of vaccinations were measured by determining anti-Myxomatosis and anti-Rabbit Haemorrhagic Disease antibodies using competitive ELISAs, and anti-Encephalitozoon cunicoli antibodies by immunocarbonassay. The environmental conditions were evaluated by measuring air temperature, relative humidity, ammonia concentration and bacterial/fungal count. Finally the productive parameters were also recorded and elaborated. All the entered values were then utilized for defining a score system to establish health and welfare conditions.展开更多
The presence,abundance,and distribution of aquatic macrophytes and their growth forms in the river Krka in Slovenia were studied.The studied slow-flowing lowland River Krka is also called a»green river«since...The presence,abundance,and distribution of aquatic macrophytes and their growth forms in the river Krka in Slovenia were studied.The studied slow-flowing lowland River Krka is also called a»green river«since it is overgrown with macrophytes from its source to its outflow to the river Sava.The environmental parameters of the river ecosystem were also assessed using the modified version of the RCE(Riparian,Channel,and Environmental Inventory)method.Within 24 sections reaching from 100 to 250 m,23 taxa of macrophytes were found.Sections were distributed noncontinuously from the source to the outflow more or less equally along the river course.The invasive alien species Elodea canadensis reached the highest relative abundance,followed by Ranunculus trichophyllus,Potamogeton crispus,Myriophyllum spicatum,Ceratophyllum demersum,and Potamogeton nodosus.Potamogeton crispus was present in most of the studied sections followed by Nasturtium officinale and M.spicatum.The river offers suitable conditions for the high diversity of macrophytes regarding the type of substrate,low flow velocity,heterogeneity of habitats,and relatively high concentrations of nutrients.In comparison to the survey performed in 2003,when the river Krka was surveyed continuously from the source to the outflow,we found that seven of the submerged and natant macrophytes were not detected in 2020.Macrophytes,growing in the river Krka,indicated meso-to eutrophic conditions.Five species recorded in the river Krka are listed on the Red list of endangered species in Slovenia,indicating the need to conserve the river ecosystem.展开更多
Offshore wind energy resources are operational in cold regions,while offshore wind turbines will face the threat of icing.Therefore,it is necessary to study icing of offshore wind turbines under different icing condit...Offshore wind energy resources are operational in cold regions,while offshore wind turbines will face the threat of icing.Therefore,it is necessary to study icing of offshore wind turbines under different icing conditions.In this study,icing sensitivity of offshore wind turbine blades are performed using a combination of FLUENT and FENSAP-ICE software,and the effects of liquid water content(LWC),medium volume diameter(MVD),wind speed and air temperature on blade icing shape are analyzed by two types of ice,namely rime ice and glaze ice.The results show that the increase of LWC and MVD will increase the amount of ice that forms on the blade surface for either glaze ice or rime ice,and an increase of MVD will expand the adhesion surface between ice and blade.Before reaching the rated wind speed of 11.4 m/s,it does not directly affect the icing shape.However,after reaching the rated wind speed,the attack angle of the incoming flow decreases obviously,and the amount of ice increases markedly.When the ambient air temperature meets the icing conditions of glaze ice(i.e.,−5℃ to 0℃),the lower the temperature,the more glaze ice freezes,whereas air temperature has no impact on the icing of rime ice.Compared with onshore wind turbines,offshore wind turbines might face extreme meteorological conditions,and the wind speed has no impact on the amount of ice that forms on the blade surface for most wind speeds.展开更多
Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat q...Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat quality(BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.展开更多
For estuaries,inland lakes play a vital role in the ecological balance under the impact of tide s.The effect of tides-induced water exchange on phytoplankton community in a semi-closed lake was studied and compared wi...For estuaries,inland lakes play a vital role in the ecological balance under the impact of tide s.The effect of tides-induced water exchange on phytoplankton community in a semi-closed lake was studied and compared with that of an adjacent closed lake in the Oujiang River mouth in Zhejiang,East China Sea,from June 29,2020 to June 14,2021.Results show that the dominant species,abundance,dominance,and diversity of the phytoplankton species between the two lakes were significantly different.In the closed lake,cyanobacteria were the dominant species during the study period.However.in the semi-closed lake,the diversification of the dominant species was greater,and some species of diatoms and green algae became dominant.The average phytoplankton abundance in the closed lake was 6 times of that in the semi-closed lake.The average dominance of cyanobacteria in the closed lake was 0.96,and those in the semi-closed lake and the Oujiang River were 0.51 and 0.22,respectively.Cyanobacterial blooms occurred throughout the study time in the closed lake but not in the semi-closed one.Furthermore,the species diversity richness of the phytoplankton in the semi-closed lake was higher than that of the closed one,and the phytoplankton community between the closed lake and semi-closed lake could be divided into distinctly different groups based on non-metic multidimensional scaling analysis(NMDS)and analysis of similarities(ANOSIM)analysis.The salinity of the water was significantly greater and the transparency significantly smaller in the semi-closed lake than those in the closed lake.Therefore,water exchange driven by local tidal movement increased salinity and decreased transparency of water,which consequently shaped the community structures of different phytoplankton and reduced the risk of a cyanobacterial bloom outbreak in the semi-closed lake.展开更多
Using radiosonde measurements from 26 July to 30 July 2014 at Baiqi over the Inner Mongolia grassland of China, the vertical structure of shallow cumulus （SCu） clouds and associated environmental conditions were inv...Using radiosonde measurements from 26 July to 30 July 2014 at Baiqi over the Inner Mongolia grassland of China, the vertical structure of shallow cumulus （SCu） clouds and associated environmental conditions were investigated. The cloud base height and the cloud top height of SCu was 3.4 km and 5 km, respectively. The temperature of the SCu layer was less than 0℃. The horizontal advection of specific humidity was smaller than the vertical transport in the atmosphere below 5 km. Above 5 km, the thermodynamic structure of the atmosphere remained stable. At the interface of the cloud layer and free air atmosphere, there was obvious wind shear and a temperature inversion （-2.9~C）. Comparisons of environmental parameters associated with cumulus congestus, rain and clear days, showed that the formation of SCu was characterized by a higher Bowen ratio （high sensible heat flux and low latent heat flux）, which indicated intensive turbulence in the boundary layer. The formation of SCu was associated with the boundary layer height exceeding the lifting condensation level. The maintenance of SCu was likely associated with the lower convective available potential energy, weak wind shear, and weak subsidence of the synoptic system, which did not favor the dramatic vertical development of SCu and thereby the transformation of SCu to cumulus congestus.展开更多
基金supported by the National Natural Science Foundation of China(No.20807004)the General Research an Development Founding for Universities directly under the Ministry of Education of China(BUCTZZ1202)
文摘Catalytic nickel was successfully incorporated into nanoscale iron to enhance its dechlorination efficiency for trichloroethylene （TCE）, one of the most commonly detected chlorinated organic compounds in groundwater. Ethane was the predominant product. The greatest dechlorination efficiency was achieved at 22 molar percent of nickel. This nanoscale Ni-Fe is poorly ordered and inhomogeneous; iron dissolution occurred whereas nickel was relatively stable during the 24-hr reaction. The morphological characterization provided significant new insights on the mechanism of catalytic hydrodcchlorination by bimetallic nanoparticles. TCE degradation and ethane production rates were greatly affected by environmental parameters such as solution pH, temperature and common groundwater ions. Both rate constants decreased and then increased over the pH range of 6.5 to 8.0, with the minimum value occurring at pH 7.5. TCE degradation rate constant showed an increasing trend over the temperature range of 10 to 25℃. However, ethane production rate constant increased and then decreased over the range, with the maximum value occurring at 20℃, Most salts in the solution appeared to enhance the reaction in the first half hour but overall they displayed an inhibitory effect. Combined ions showed a similar effect as individual salts.
文摘Accurately predicting environmental parameters in solar greenhouses is crucial for achieving precise environmental control.In solar greenhouses,temperature,humidity,and light intensity are crucial environmental parameters.The monitoring platform collected data on the internal environment of the solar greenhouse for one year,including temperature,humidity,and light intensity.Additionally,meteorological data,comprising outdoor temperature,outdoor humidity,and outdoor light intensity,was gathered during the same time frame.The characteristics and interrelationships among these parameters were investigated by a thorough analysis.The analysis revealed that environmental parameters in solar greenhouses displayed characteristics such as temporal variability,non-linearity,and periodicity.These parameters exhibited complex coupling relationships.Notably,these characteristics and coupling relationships exhibited pronounced seasonal variations.The multi-parameter multi-step prediction model for solar greenhouse(MPMS-SGH)was introduced,aiming to accurately predict three key greenhouse environmental parameters,and the model had certain seasonal adaptability.MPMS-SGH was structured with multiple layers,including an input layer,a preprocessing layer,a feature extraction layer,and a prediction layer.The input layer was used to generate the original sequence matrix,which included indoor temperature,indoor humidity,indoor light intensity,as well as outdoor temperature and outdoor light intensity.Then the preprocessing layer normalized,decomposed,and positionally encoded the original sequence matrix.In the feature extraction layer,the time attention mechanism and frequency attention mechanism were used to extract features from the trend component and the seasonal component,respectively.Finally,the prediction layer used a multi-layer perceptron to perform multi-step prediction of indoor environmental parameters(i.e.temperature,humidity,and light intensity).The parameter selection experiment evaluated the predictive performance of MPMS-SGH on input and output sequences of different lengths.The results indicated that with a constant output sequence length,the prediction accuracy of MPMS-SGH was firstly increased and then decreased with the increase of input sequence length.Specifically,when the input sequence length was 100,MPMS-SGH had the highest prediction accuracy,with RMSE of 0.22℃,0.28%,and 250lx for temperature,humidity,and light intensity,respectively.When the length of the input sequence remained constant,as the length of the output sequence increased,the accuracy of the model in predicting the three environmental parameters was continuously decreased.When the length of the output sequence exceeded 45,the prediction accuracy of MPMS-SGH was significantly decreased.In order to achieve the best balance between model size and performance,the input sequence length of MPMS-SGH was set to be 100,while the output sequence length was set to be 35.To assess MPMS-SGH’s performance,comparative experiments with four prediction models were conducted:SVR,STL-SVR,LSTM,and STL-LSTM.The results demonstrated that MPMS-SGH surpassed all other models,achieving RMSE of 0.15℃for temperature,0.38%for humidity,and 260lx for light intensity.Additionally,sequence decomposition can contribute to enhancing MPMS-SGH’s prediction performance.To further evaluate MPMS-SGH’s capabilities,its prediction accuracy was tested across different seasons for greenhouse environmental parameters.MPMS-SGH had the highest accuracy in predicting indoor temperature and the lowest accuracy in predicting humidity.And the accuracy of MPMS-SGH in predicting environmental parameters of the solar greenhouse fluctuated with seasons.MPMS-SGH had the highest accuracy in predicting the temperature inside the greenhouse on sunny days in spring(R^(2)=0.91),the highest accuracy in predicting the humidity inside the greenhouse on sunny days in winter(R^(2)=0.83),and the highest accuracy in predicting the light intensity inside the greenhouse on cloudy days in autumm(R^(2)=0.89).MPMS-SGH had the lowest accuracy in predicting three environmental parameters in a sunny summer greenhouse.
基金This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the BlueBRIDGE project[grant agreement no 675680].
文摘Forecasting environmental parameters in the distant future requires complex modelling and large computational resources.Due to the sensitivity and complexity of forecast models,long-term parameter forecasts(e.g.up to 2100)are uncommon and only produced by a few organisations,in heterogeneous formats and based on different assumptions of greenhouse gases emissions.However,data mining techniques can be used to coerce the data to a uniform time and spatial representation,which facilitates their use in many applications.In this paper,streams of big data coming from AquaMaps and NASA collections of 126 long-term forecasts of nine types of environmental parameters are processed through a cloud computing platform in order to(i)standardise and harmonise the data representations,(ii)produce intermediate scenarios and new informative parameters,and(iii)align all sets on a common time and spatial resolution.Time series crosscorrelation applied to these aligned datasets reveals patterns of climate change and similarities between parameter trends in 10 marine areas.Our results highlight that(i)the Mediterranean Sea may have a standalone‘response’to climate change with respect to other areas,(ii)the Poles are most representative of global forecasted change,and(iii)the trends are generally alarming for most oceans.
文摘Air distribution of HVAC systems is the most popular type used in the building sector,having a relevant impact on indoor air quality and occupant wellness.Many types of research developed optimal solutions for the HVAC system’s design,focusing on specific components of the distribution system,on the airflow and geometry of ducts,on the size of ducts,on the shape and position of air diffusers.However,few works in literature proposed a globally experimental and simulation analysis of an air distribution system with a variable mass flaw rate.Along this line,the presented research investigates the potentialities of a new ceiling diffuser,installed in an exhibition room.This system provides a variable mass flow rate thanks to its configuration,providing adequate thermal comfort.A warm wall is chosen as the heating system.Several tests are carried out,six for cooling and two for heating with different volumetric air rates and supply air temperature of the diffusers.The combination of two methods,the measurement campaigns and the computational fluid dynamics(CFD)technique represent a suitable approach to examine the thermal indoor environment.In general,results show a strong capability of this diffuser to provide a uniform temperature and velocity field inside the room.Moreover,experimental and numerical data are significantly comparable with an average deviation of 1%for the velocity and lower 1%for the temperature,guaranteeing an optimal distribution of the understudy environmental parameters on the vertical and horizontal planes.
基金Supported by the National Natural Science Foundation of China(No.52071306)the Natural Science Foundation of Shandong Province(No.ZR2019MEE050)。
文摘The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainties in the calculation of marine environmental design parameters,a general model uncertainty assessment method is necessary.We proposed a new multivariate model uncertainty assessment method for the calculation of marine environmental design parameters.The method divides the overall model uncertainty into two categories:aleatory uncertainty and epistemic uncertainty.The aleatory uncertainty of the model is obtained by analyzing the influence of the number and the dispersion degree of samples on the information entropy of the model.The epistemic uncertainty of the model is calculated using the information entropy of the model itself and the prediction error.The advantages of this method are that it does not require many-year-observation data for the marine environmental elements,and the method can be used to analyze any specific factors that cause model uncertainty.Results show that by applying the method to the South China Sea,the aleatory uncertainty of the model increases with the number of samples and then stabilizes.A positive correlation was revealed between the dispersion of the samples and the aleatory uncertainty of the model.Both the distribution of the model and the parameter estimation results of the model have significant effects on the epistemic uncertainty of the model.When the goodness-of-fit of the model is relatively close,the best model can be selected according to the criterion of the lowest overall uncertainty of the models,which can both ensure a better model fit and avoid too much uncertainty in the model calculation results.The presented multivariate model uncertainty assessment method provides a criterion to measure the advantages and disadvantages of the marine environmental design parameter calculation model from the aspect of uncertainty,which is of great significance to analyze the uncertainties in the calculation of marine environmental design parameters and improve the accuracy of the calculation results.
文摘In this article the corrosion rate of the austenitic stainless steel type 304, under the synergistic effect of environmental factors has been assessed via potentiodynamic polarization scan.Salinity, velocity, pH and temperature are the factors which induce effects on the corrosion rate of the considered metal.Quantitative analysis is applied using the full two-level factorial experimental design method, which results in the contribution value of each parameter in changing the quantity of average corrosion rate in both individual and synergistic cases.Besides this quantitative analysis, qualitative analysis has been used to predict the variation direction.These two analyses show the important role of the synergistic action, which changes the variation direction of corrosion rate and the contribution percentage of each parameter in varying the value of corrosion rate.Applying both these analyses can show the magnitude and quality of each parameter＇s effect, which is remarkably valuable in marine applications.
文摘Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.
基金supported by Technologies R&D of State Administration of Work Safety (06-399)Technologies R&D of Hunan Province ( No.05FJ4071)
文摘In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production and security conditions. The client computer can convert the analog signal about the safety in production and environmental parameters detected from the monitoring terminal into digital signal,and then,send the signal to the coal mine safety monitoring centre. This information can be analyzed,judged,and diagnosed by the monitoring-management-controlling software for helping the manager and technical workers to control the actual underground production and security situations. The system has many advantages including high reliability,better performance of real-time monitoring,faster data communicating and good practicability,and it can effectively prevent the occurrence of safety incidents in coal mines.
基金Project supported by the National Natural Science Foundation of China (Grant No. 62403150)the Innovation Project of Guangxi Graduate Education (Grant No. YCSW2024129)the Guangxi Science and Technology Base and Talent Project (Grant No. Guike AD23026208)。
文摘The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the π-pulse sequences(both equidistant and optimized)to a quantum probe coupled to a bosonic environment. To demonstrate the precision of cutoff frequency estimation, we theoretically derive the quantum Fisher information(QFI) and quantum signal-to-noise ratio(QSNR) across sub-Ohmic,Ohmic, and super-Ohmic environments, and investigate their behaviors through numerical examples. The results indicate that, compared to the equidistant π-pulse sequence, the optimized π-pulse sequence significantly shortens the time to reach maximum QFI while enhancing the precision of cutoff frequency estimation, particularly in deep sub-Ohmic and deep super-Ohmic environments.
文摘Soil CO<sub>2</sub> efflux is an ongoing process of respiration from soil;plant parts/ microbes below the ground to the atmosphere which is known for faster cycling of carbon sources. A large portion of carbon sequestered and fixed by forests is returned to the atmosphere through soil CO<sub>2</sub> efflux and multiple controlling parameters mainly temperature, precipitation, and growth factors interact with the soil CO<sub>2</sub> efflux variation. This study assessed the soil CO<sub>2</sub> efflux every month for consecutive 2-years (August 2015 to July 2017) by using the closed chamber method to determine the role of ecological parameters that govern the soil CO<sub>2</sub> efflux and its temporal modification in a sub-tropical mixed forest of central region in Nepal. The results of this study manifested that soil CO<sub>2</sub> efflux accounted 63.2% (y = 31.96e<sup>0.128x</sup>), 71.3% (y = 44.77e<sup>0.123x</sup>) and 64.5% (y = 44.11e<sup>0.117x</sup>) variations in soil temperature with significantly (p < 0.05) exponential positive relation in the year 2015/2016, 2016/2017 and the two years when merged. And the temperature sensitivity value (Q<sub>10</sub>) of the soil CO<sub>2</sub> efflux was 3.6, 3.4, and 3.2, respectively. Soil water content also expressed significantly (p < 0.05) positive exponential effect on soil CO<sub>2</sub> efflux and accounted 62.0% (y = 138.3e<sup>0.057x</sup>), 46.1% (y = 88.42e<sup>0.052x</sup>) and 40.5% (y = 133.1e<sup>0.0447x</sup>) in its variability in different years and the merged years. Evident variations of soil CO<sub>2</sub> efflux, soil temperature, soil water content, and litter were observed in the forest seasonally and inter-annually. Two years mean total annual soil CO<sub>2</sub> efflux of the forest was estimated at 904.76 g C·m<sup>-2</sup>·y<sup>-1</sup>. The study revealed that sub-tropical forests could be more influenced by precipitation regimes in progressing warm climates i.e. vulnerable to climate change, illustrating the comprehensive dynamics of the representative forest carbon cycle in the tropical region.
文摘An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at May 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.
文摘An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at May 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.
文摘The manual selection of environment parameters during welding simulation will bring a significant error to the simulation result of welding temperature field. By a combination of finite element method （FEM） and infrared thermography, these environment parameters were inversed mathematically in place of previous manual selection. First, FEM model of the welding process was constructed, and the temperature field was computed with initial environment parameters. Then, a real welding process was conducted and the temperature field was measured by infrared thermography. Last, the simulation and measurement results were compared, and the environment parameters were adjusted continuously with the genetic algorithm （ GA ） until the simulation matched the measurement best. Parameters according to the best-matched simulation results were considered as the most appropriate parameters.
基金National Key Research and Development Program of China(2019YFC1510400)National Natural Science Foundation of China(41975056,41675045)。
文摘Composite radar reflectivity data during April-September 2011-2015 are used to investigate and classify storms in south China(18-27°N;105-120°E). The storms appear most frequently in May. They are either linear;cellular or nonlinear systems, taking up 29.45%, 24.51% and 46.04%, respectively, in terms of morphology. Linear systems are subdivided into six morphologies: trailing stratiform precipitation(TS), bow echoes(BE), leading stratiform precipitation(LS), embedded line(EL), no stratiform precipitation(NS) and parallel stratiform precipitation(PS). The TS and NS modes have the highest frequencies but there are only small samples of LS(0.61%) and PS(0.79%) modes.Severe convective wind(≥17m s-1at surface level) accounts for the highest percentage(35%) of severe convective weather events produced by cellular systems including individual cells(IC) and clusters of cells(CC). Short-duration heavy rainfall(≥50 mm h-1) and severe convective wind are the most common severe weather associated with TS and BE modes. Comparison of environmental physical parameters shows that cellular convection systems tend to occur in the environment with favorable thermal condition, substantial unstable energy and low precipitable water from the surface to300 hPa(PWAT). However, the environmental conditions favoring the initiation of linear systems feature strong vertical wind shear, high PWAT, and intense convective inhibition. The environmental parameters favoring the initiation of nonlinear systems are between those of the other two types of morphology.
文摘The knowledge on rabbit welfare may be improved by the use of correct tools for monitoring the different aspects of rabbit industrial farming. Therefore, the aim of this study was to define parameters related to health and welfare of animals in industrial farms with intensive husbandry. Health, management, environmental and productive parameters were firstly characterized and then a protocol to assess welfare of rabbits was define. The research was conducted on 8 industrial farms from 2004 to 2007 and around 30 inspections were done in each farm. At each visit, the health conditions were established by： （1） necropsy on animals of different productive category; （2） specific laboratory investigations based on the lesions observed; （3） checking the presence of parasites in environmental faecal samples; （4） bacteriological examination of vaginal, nasal and rectal swabs of rabbit of different age. The immune conditions and the efficacy of vaccinations were measured by determining anti-Myxomatosis and anti-Rabbit Haemorrhagic Disease antibodies using competitive ELISAs, and anti-Encephalitozoon cunicoli antibodies by immunocarbonassay. The environmental conditions were evaluated by measuring air temperature, relative humidity, ammonia concentration and bacterial/fungal count. Finally the productive parameters were also recorded and elaborated. All the entered values were then utilized for defining a score system to establish health and welfare conditions.
基金Javna Agencija za Raziskovalno Dejavnost RS,Grant/Award Number:P1-0212。
文摘The presence,abundance,and distribution of aquatic macrophytes and their growth forms in the river Krka in Slovenia were studied.The studied slow-flowing lowland River Krka is also called a»green river«since it is overgrown with macrophytes from its source to its outflow to the river Sava.The environmental parameters of the river ecosystem were also assessed using the modified version of the RCE(Riparian,Channel,and Environmental Inventory)method.Within 24 sections reaching from 100 to 250 m,23 taxa of macrophytes were found.Sections were distributed noncontinuously from the source to the outflow more or less equally along the river course.The invasive alien species Elodea canadensis reached the highest relative abundance,followed by Ranunculus trichophyllus,Potamogeton crispus,Myriophyllum spicatum,Ceratophyllum demersum,and Potamogeton nodosus.Potamogeton crispus was present in most of the studied sections followed by Nasturtium officinale and M.spicatum.The river offers suitable conditions for the high diversity of macrophytes regarding the type of substrate,low flow velocity,heterogeneity of habitats,and relatively high concentrations of nutrients.In comparison to the survey performed in 2003,when the river Krka was surveyed continuously from the source to the outflow,we found that seven of the submerged and natant macrophytes were not detected in 2020.Macrophytes,growing in the river Krka,indicated meso-to eutrophic conditions.Five species recorded in the river Krka are listed on the Red list of endangered species in Slovenia,indicating the need to conserve the river ecosystem.
基金financially supported by the National Natural Science Foundation of China(Grant No.51879125)the Jiangsu Provincial Higher Education Natural Science Research Major Project(Grant No.18KJA580003)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20211342)the Jiangsu Province“Six Talents Peak”High-level Talents Support Project(Grant No.2018-KTHY-033).
文摘Offshore wind energy resources are operational in cold regions,while offshore wind turbines will face the threat of icing.Therefore,it is necessary to study icing of offshore wind turbines under different icing conditions.In this study,icing sensitivity of offshore wind turbine blades are performed using a combination of FLUENT and FENSAP-ICE software,and the effects of liquid water content(LWC),medium volume diameter(MVD),wind speed and air temperature on blade icing shape are analyzed by two types of ice,namely rime ice and glaze ice.The results show that the increase of LWC and MVD will increase the amount of ice that forms on the blade surface for either glaze ice or rime ice,and an increase of MVD will expand the adhesion surface between ice and blade.Before reaching the rated wind speed of 11.4 m/s,it does not directly affect the icing shape.However,after reaching the rated wind speed,the attack angle of the incoming flow decreases obviously,and the amount of ice increases markedly.When the ambient air temperature meets the icing conditions of glaze ice(i.e.,−5℃ to 0℃),the lower the temperature,the more glaze ice freezes,whereas air temperature has no impact on the icing of rime ice.Compared with onshore wind turbines,offshore wind turbines might face extreme meteorological conditions,and the wind speed has no impact on the amount of ice that forms on the blade surface for most wind speeds.
基金supported by the NSFC-Shandong Joint Fund for Marine Science Research Centers (Grant No. U1406404)the National Marine Public Welfare Research Project of China (Grant No. 201405007)
文摘Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat quality(BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.
基金Supported by the National Key R&D Program of China(No.2018YFE0103700)the National Natural Science Foundation(Nos.41876124,61871293,42007372)the Zhejiang Provincial Natural Science Foundation of China(Nos.LZ21C030001,LD21C030001,LQ20C030008)。
文摘For estuaries,inland lakes play a vital role in the ecological balance under the impact of tide s.The effect of tides-induced water exchange on phytoplankton community in a semi-closed lake was studied and compared with that of an adjacent closed lake in the Oujiang River mouth in Zhejiang,East China Sea,from June 29,2020 to June 14,2021.Results show that the dominant species,abundance,dominance,and diversity of the phytoplankton species between the two lakes were significantly different.In the closed lake,cyanobacteria were the dominant species during the study period.However.in the semi-closed lake,the diversification of the dominant species was greater,and some species of diatoms and green algae became dominant.The average phytoplankton abundance in the closed lake was 6 times of that in the semi-closed lake.The average dominance of cyanobacteria in the closed lake was 0.96,and those in the semi-closed lake and the Oujiang River were 0.51 and 0.22,respectively.Cyanobacterial blooms occurred throughout the study time in the closed lake but not in the semi-closed one.Furthermore,the species diversity richness of the phytoplankton in the semi-closed lake was higher than that of the closed one,and the phytoplankton community between the closed lake and semi-closed lake could be divided into distinctly different groups based on non-metic multidimensional scaling analysis(NMDS)and analysis of similarities(ANOSIM)analysis.The salinity of the water was significantly greater and the transparency significantly smaller in the semi-closed lake than those in the closed lake.Therefore,water exchange driven by local tidal movement increased salinity and decreased transparency of water,which consequently shaped the community structures of different phytoplankton and reduced the risk of a cyanobacterial bloom outbreak in the semi-closed lake.
基金funded by National Science Foundation of China (Grant No. 40975001 and 61327810)the State Key Project of Research and Development Plan (Grant No. 2016YFC0200403)
文摘Using radiosonde measurements from 26 July to 30 July 2014 at Baiqi over the Inner Mongolia grassland of China, the vertical structure of shallow cumulus （SCu） clouds and associated environmental conditions were investigated. The cloud base height and the cloud top height of SCu was 3.4 km and 5 km, respectively. The temperature of the SCu layer was less than 0℃. The horizontal advection of specific humidity was smaller than the vertical transport in the atmosphere below 5 km. Above 5 km, the thermodynamic structure of the atmosphere remained stable. At the interface of the cloud layer and free air atmosphere, there was obvious wind shear and a temperature inversion （-2.9~C）. Comparisons of environmental parameters associated with cumulus congestus, rain and clear days, showed that the formation of SCu was characterized by a higher Bowen ratio （high sensible heat flux and low latent heat flux）, which indicated intensive turbulence in the boundary layer. The formation of SCu was associated with the boundary layer height exceeding the lifting condensation level. The maintenance of SCu was likely associated with the lower convective available potential energy, weak wind shear, and weak subsidence of the synoptic system, which did not favor the dramatic vertical development of SCu and thereby the transformation of SCu to cumulus congestus.
