The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption a...The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption amount of CO2and the separation coefficient with N2for all amines loaded.However,the effect of loading trialkylamines is not remarkable in the absence of water.The effect of loading dialkylamine does not depend on water,but the adsorbent cannot be regenerated at ambient temperature.In comparison,an adsorbent loading trialkylamine can be regenerated at ambient temperature even in the presence of water with fairly good stability.展开更多
A MnOx-NbOx-CeO2 catalyst for low temperature selective catalytic reduction（SCR） of NOx with NH3 was prepared by a sol-gel method, and characterized by NH3-NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, N...A MnOx-NbOx-CeO2 catalyst for low temperature selective catalytic reduction（SCR） of NOx with NH3 was prepared by a sol-gel method, and characterized by NH3-NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, NOx/NH3 TPD, XRD, BET, H2-TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy（DRIFTS）. The results indicate that the Mn Ox-Nb Ox-CeO2 catalyst shows excellent low temperature NH3-SCR activity in the temperature range of 150-300℃. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NOx adsorption. As the NO2 content increases in the feed, water vapor does not affect the activity in NO2 SCR. Meanwhile, water vapor significantly enhances the N2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH4NO3 into N2O.展开更多
The water promotion effects,where water can provide a solution-mediated reaction pathway in various heterogeneous chemical catalysis,have been presented and attracted wide attention recently,yet,the rational design of...The water promotion effects,where water can provide a solution-mediated reaction pathway in various heterogeneous chemical catalysis,have been presented and attracted wide attention recently,yet,the rational design of catalysts with a certain ability of enhancing water-induced reaction process is full of challenges and difficulties.Here,we show that by incorporating alkali(Na,K)cations as an electronic and/or structural promoter into Pd/rGO-ZnCr_(2)O_(4)(r GO,reduced graphene oxide),the obtained Pd(Na)/rGO-ZnCr_(2)O_(4)as a representative example demonstrates an outstanding benzyl alcohol oxidation activity in the Pickering emulsion system in comparison to the alkali-free counterpart.The response experiments of water injection confirm the enhanced activity,and the Na-modified catalyst can further enhance the promotion effects of water on the reaction.The effects of alkali cations for Pd nanoparticles are identified and deciphered by a series of experimental characterizations(XPS,in situ CO-DRIFTS,and CO-TPR coupled with MS),showing that there is abundant-OH on the surface of the catalyst,which is stabilized by the formation of Pd-OH_(x).The alkali-stabilized Pd-OH_(x)is helpful to enhance the waterinduced reaction process.According to the results of in situ Raman as well as UV-vis absorption spectra,the Na-modulated Pd(Na)/rGO-ZnCr_(2)O_(4)enables the beneficial characteristics for distorting the benzyl alcohol structure and enhancing the adsorption of benzyl alcohol.Further,the mechanism for enhanced water promotion effects is rationally proposed.The strategy of alkali cations-modified catalysts can provide a new direction to effectively enhance the chemical reaction involving small molecule water.展开更多
The preparation of conducting PPQ film was first reported in the previous paper. It is very interesting that this film is highly sensitive to moisture in air. The hydration and dehydration of the film are accompanied ...The preparation of conducting PPQ film was first reported in the previous paper. It is very interesting that this film is highly sensitive to moisture in air. The hydration and dehydration of the film are accompanied by change not only in color but also in conductivity and UV-visible spectrum. The conducting PPQ is reduced to PPQ and loses its conductivity after being soaked in water.展开更多
Transport properties and the associated structural heterogeneity of room temperature aqueous ionic liquids and especially of super-concentrated electrolyte aqueous solutions have received increasing attention,due to t...Transport properties and the associated structural heterogeneity of room temperature aqueous ionic liquids and especially of super-concentrated electrolyte aqueous solutions have received increasing attention,due to their potential application in ionic battery.This paper briefly reviews the results reported mainly since 2010 about the liquid-liquid separation,aggregation of polar and apolar domains in neat RTILs,and solvent clusters and 3D networks chiefly constructed by anions in super-concentrated electrolyte solutions.At the same time,the dominating effect of desolvation process of metal ions at electrode/electrolyte interface upon the transport of metal ions is stressed.This paper also presents the current understanding of how water affects the anion-cation interaction,structural heterogeneities,the structure of primary coordination sheath of metal ions and consequently their transport properties in free water-poor electrolytes.展开更多
1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water ...1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water surface for an extended period.With the emergence of cross-media rotorcraft, rotor wakes interact violently with the water surface to generate large-scale,air–water droplet mixed flows (hereafter referred to as mixed air–water flows). Rotors operating in mixed air–water flows always have aerodynamic performances that are different from those owing to the In-Ground Effect (IGE) and Out-of Ground Effect (OGE). Accordingly, this effect is called the Near-Water Effect (NWE) of the rotor2,and it usually causes thrust loss and torque increase.展开更多
Blending the agility of aerial drones with the covert capabilities of underwater submersibles,the aerial-aquatic rotorcraft has garnered substantial interest due to their unparalleled capacity to traverse both air and...Blending the agility of aerial drones with the covert capabilities of underwater submersibles,the aerial-aquatic rotorcraft has garnered substantial interest due to their unparalleled capacity to traverse both air and water.Nevertheless,a critical hurdle for these vehicles lies in mitigating the adverse effects of repeatedly transitioning between these environments,particularly during water-surface takeoffs.Currently,research on the interference caused by rotors approaching water surfaces remains limited.This paper introduces a novel adaptive rotor aerodynamic model based on continuous finite vortex theory to predict rotor thrust within gas–liquid flow field.Initially,the model's sensitivity to system parameters was analyzed to optimize its predictive capabilities.Subsequently,a comprehensive ground/water experimental setup was designed to investigate the intricate aerodynamic interactions between the rotor flow field and water.By varying rotor sizes,the characteristics of the rotor flow field and water surface were examined at different rotor-water surface distances.The performance of different modeling methods was analyzed based on the rotor experimental data of a diameter of 0.38 m,and the prediction results were quantified using the percentage of the mean-square error.The results show that the average error of the finite vortex rotor model is the smallest.Finally,a novel transition boundary is proposed to divide the rotor flow field of the gas–liquid mixture into two stages.The thrust loss zone is defined to delineate the safe operating range of the aircraft,providing a basis for the design of aerial-aquatic rotorcraft.展开更多
CeO2-MOx (M=Cu, Mn, Fe, Co, and Ni) mixed oxide catalysts were prepared by a citric acid complexation-combustion method. CeO2-MOx solid solutions could be formed with M cations doping into CeO2 lattice, while NiO and ...CeO2-MOx (M=Cu, Mn, Fe, Co, and Ni) mixed oxide catalysts were prepared by a citric acid complexation-combustion method. CeO2-MOx solid solutions could be formed with M cations doping into CeO2 lattice, while NiO and Co3O4 phases were detected on the surface of CeO2-NiO and CeO2-Co3O4 by Raman spectroscopy. The presence of M in CeO2 could obviously promote its catalytic activity for CH4 catalytic combustion and CO oxidation. Among the prepared samples, CeO2-CuO exhibited the best performance for CO oxidatio...展开更多
To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experimen...To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experiments were used to validate the effects of using surfactants;the results show that after dealing with vacuum saturation with water,the volume of micropores decreases,which results in a larger average pore size,and the volume of transitional pores,mesopores,macropores and total pores increases.Based on the distribution of pore size,the operation mode of ‘‘water infusion after gas extraction,then continuing gas extraction" is recommended to improve the volume of coal mine gas drainage.When the reflectance of vitrinite in coal samples is less than 1,using the surfactants Fast T,1631,APG,BS can mitigate the damage caused by the water blocking effect.But when the reflectance of vitrinite is larger than 1.4,the damage caused by the water blocking effect can be increased.When the surfactant CMC is used in hydraulic applications,the capillary forces of coal samples are almost negative,which means the capillary force is in the same direction as the gas extraction.The direction of capillary forces benefits the gas flow.So,using CMC can play an active role in removing the water blocking effect.Centrifugal experiments confirm that using CMC can effectively remove the water blocking effect,which has a beneficial effect on improving the gas drainage volume.展开更多
The inactivation effects of pressurized CO2 against bacteriophage Qβ and ФX 174 were investigated under the pressure of 0.3-0.9 MPa, initial concentration of 107-109 PFU/mL, and temperature of 17.8℃-27.2℃. The opt...The inactivation effects of pressurized CO2 against bacteriophage Qβ and ФX 174 were investigated under the pressure of 0.3-0.9 MPa, initial concentration of 107-109 PFU/mL, and temperature of 17.8℃-27.2℃. The optimum conditions were found to be 0.7 MPa and an exposure time of 25 min. Under identical treatment conditions, a greater than 3.3-log reduction in bacteriophage Qβ was achieved by CO2, while a nearly 3.0 log reduction was observed for phage ФX174. The viricidal effects of N2O （an inactivation gas with similar characteristics to CO2）, normal acid （HC1）, and CO2 treatment with phosphate buffered saline affirmed the chemical nature of CO2 treatment. The pumping cycle, depressurization rate, and release of intracellular substances caused by CO2 were its viricidal mechanisms. The results indicate that CO2 has the potential for use as a disinfectant without forming disinfection by-products.展开更多
The water effect on peroxy radical measurement by chemical amplification was determined experimentally for HO2 and HO2+OH, respectively at room temperature (298±2) K and atmospheric pressure (1×105 Pa). No s...The water effect on peroxy radical measurement by chemical amplification was determined experimentally for HO2 and HO2+OH, respectively at room temperature (298±2) K and atmospheric pressure (1×105 Pa). No significant difference in water effect was observed with the type of radicals. A theoretical study of the reaction of HO2·H2O adduct with NO was performed using density functional theory at CCSD(T)/6-311 G(2d, 2p)//B3LYP/6-311 G(2d, 2p) level of theory. It was found that the primary reaction channel for the reaction is HO2·H2O+NO→HNO3+H2O (R4a). On the basis of the theoretical study, the rate constant for (R4a) was calculated using Polyrate Version 8.02 program. The fitted Arrenhnius equation for (R4a) is k = 5.49×107 T 1.03exp(?14798/T) between 200 and 2000 K. A chemical model incorporated with (R4a) was used to simulate the water effect. The water effect curve obtained by the model is in accordance with that of the experiment, suggesting that the water effect is probably caused mainly by (R4a).展开更多
The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on w...The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on water loss ratio were consistent with those on drying shrinkage strain. It is also indicated that drying shrinkage strain has obvious linear correlation with water loss ratios independent of specimen size and shape. The effects of specimen size and shape on the water loss ratio were embodied in established model of averaged relative humidity improved by considering effects of sequential hydration and calculated by finite difference method. Furthermore, the effects of specimen size and shape on drying shrinkage strain of concrete were experimentally deduced and applied to modify criterion EB-FIP1990. The comparison between experimental and calculated results shows that the modified EB-FIP1990 can be adopted to predict drying shrinkage strain of concrete with reasonable accuracy.展开更多
Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertili...Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertilizer application,and vice versa;pods per plant,seeds per pod.and 100-seed weight had positive correlations with soybean yield,but the degrees of correlations of different treatments were various;LAI and dry matter accumulation could be significantly increased when watered and applied fertilizer with different levels,but high fertilizer application treatment didn't obtain the highest yield;watering could increase the absolute absorption amount of N,P,K in seeds,but the accumulation rates were various.展开更多
The Microcystis sample was selected from natural bloom water,then the algicidal effects of the bacterial strain fluid of the two algicidal bacteria,supernatant and bacterial liquid were studied. Moreover,the changes o...The Microcystis sample was selected from natural bloom water,then the algicidal effects of the bacterial strain fluid of the two algicidal bacteria,supernatant and bacterial liquid were studied. Moreover,the changes of microalgae colony and morphology in the process of algae-lysing were observed using neutral red staining and scanning electron microscope. It showed that AA06 bacteria had certain algicidal effect while AA10 bacteria had no effect. All the supernatants of the two bacterial strains had obvious algicidal effects,and the algicidal effects between the bacterial liquid and supernatant had no significant differences( P < 0. 05). The effects of algae-lysing mainly owed to the chemical substances secreted by algicidal bacteria. During the algae-lysing process,the algae colony did not disperse into individual cells. The segments of the dead cells still aggregated together.展开更多
Manganese and ammonium pollution in surface water sources has become a serious issue.In this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simult...Manganese and ammonium pollution in surface water sources has become a serious issue.In this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simultaneous removal of ammonium and manganese from surface water using a manganese co-oxide filter film(MeO_x ). The results showed that the manganese removal efficiency of MeO_x in the absence of ammonium was high and stable, and the removal efficiency could reach 70% even at 5.5 °C. When the influent ammonium concentration was lower than 0.7 mg/L, ammonium and manganese could be removed simultaneously. However, at an ammonium concentration of 1.5 mg/L, the manganese removal efficiency of the filter gradually decreased with time(from 96% to 46.20%). Nevertheless, there was no impact of manganese on ammonium removal. The mechanism by which ammonium negatively affected manganese removal was investigated, demonstrating that ammonium affected manganese removal mainly through two possible mechanisms. On one hand, the decreased p H caused by ammonium oxidation was unfavorable for the oxidation of manganese by MeO_x ; on the other hand, the presence of ammonium slowed the growth of new MeO_x and retarded the increase in the specific surface area of the Me Ox-coated sand, and induced changes in the morphology and crystal structure of Me Ox. Consequently, the manganese removal efficiency of the filter decreased when ammonium was present in the inlet water.展开更多
Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). Howev...Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). However, the conformational change of DOM resultant from water chemistry and concentrations of DOM was not extensively investigated; therefore, the contradictory reports regarding the binding property with HOCs were available in literature. In this study, the effects of ionic strength, pH and DOM concentrations on the fluorescence properties of two humic acids (HA), namely Fluka HA and Amherst HA, were investigated by three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) and steady-state fluorescence polarization (FP) techniques. The results not only corroborated previous observations obtained by other investigators, but revealed some new information about the fluorescence properties and molecular conformation of the humic acids under different water chemistry and DOM concentration conditions, which could shed light on its binding mechanisms and binding properties with HOCs.展开更多
Based on the observation data of rainfall,vegetation,runoff and sediment yield in the experimental plots located in Hetian Town,Changting County of Fujian Province during 2007-2010,the changing characteristics and int...Based on the observation data of rainfall,vegetation,runoff and sediment yield in the experimental plots located in Hetian Town,Changting County of Fujian Province during 2007-2010,the changing characteristics and interrelation of live vegetation volume of grass,rainfall parameters,and water(soil)conservation effect RE(SE)were analyzed at four time scales of rainfall event,month,season,and year.The results showed that with the increase of time scales,the rainfall and vegetation indicators increased or decreased more or less,and the variation range of RE was small,while SEslowly decreased.The mean REchanged by 10%-20% at different time scales,and the observed water conservation effect of the grassland was the best at season scale while the worst at year scale.The soil conservation effect of the grassland was the best at month scale and the worst at season scale.The water conservation effect of the grass was mainly controlled by rainfall factors,including rainfall duration and precipitation at rainfall event scale,and the maximum intensity of precipitation within 30 min at longer time scales.However,the soil conservation effect of the grass was mainly controlled by vegetation factors,including the contribution of the litter on soil surface at rainfall event scale,the interaction of rainfall and vegetation at month and season scales,and the live vegetation volume of the grass at year scale.Consequently,at different time scales,the factors influencing water and soil conservation changed and interacted,and the observed water and soil conservation effects were also different,indicating that the influence of time scales deserves attention in both research and management practices.展开更多
Ammonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ...Ammonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ammonium pollution comes from diffuse agricultural sources, making control difficult, industrial or municipal point sources such as wastewater treatment plants also contribute significantly to overall ammonium pollution.These latter sources can be targeted more readily to control ammonium release into water systems. To assist policy makers and researchers in understanding the diversity of treatment options and the best option for their circumstance, this paper produces a comprehensive review of existing treatment options for ammonium removal with a particular focus on those technologies which offer the highest rates of removal and cost-effectiveness. Ion exchange and adsorption material methods are simple to apply, cost-effective, environmentally friendly technologies which are quite efficient at removing ammonium from treated water. The review presents a list of adsorbents from the literature, their adsorption capacities and other parameters needed for ammonium removal. Further, the preparation of adsorbents with high ammonium removal capacities and new adsorbents is discussed in the context of their relative cost, removal efficiencies, and limitations. Efficient, cost-effective, and environmental friendly adsorbents for the removal of ammonium on a large scale for commercial or water treatment plants are provided. In addition, future perspectives on removing ammonium using adsorbents are presented.展开更多
A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the b...A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the broadband signals. It is observed that the transmission loss （TL） decreases up to 7 dB for the signals in the first shadow zone due to the seamount reflection. Moreover, the TL might increase more than 30 dB in the converge zone due to the shadowing by seamounts. Abnormal TLs and pulse arrival structures at different ranges are explained by using the ray and wave theory. The experimental TLs and arrival pulses are compared with the numerical results and found to be in good agreement.展开更多
The functioning mechanism of groundwater and its make-up water in the process of ground subsidence was studied from such three aspects as osmotic corrasion, osmotic pressure effect and concretion effect, As to osmotic...The functioning mechanism of groundwater and its make-up water in the process of ground subsidence was studied from such three aspects as osmotic corrasion, osmotic pressure effect and concretion effect, As to osmotic corrasion, its forming conditions, mechanical mechanism and process were analyzed, As to osmotic pressure effect, it was mainly studied from hydrostatic pressurizing effect, sop softening effect and negative pressure sealing effect. Through concretion and saturation of soil, the factors of concretion settlement were analyzed. The results showed that both groundwater and its make-up water are important triggering factors to ground subsidence.展开更多
基金Supported by National Natural Science Foundation of China(No.20876114)
文摘The adsorption of CO2can be enhanced through loading amines on adsorbents,therefore,the separation of CO2from other gases is promoted.Water plays an important role in this process.Water increases both the adsorption amount of CO2and the separation coefficient with N2for all amines loaded.However,the effect of loading trialkylamines is not remarkable in the absence of water.The effect of loading dialkylamine does not depend on water,but the adsorbent cannot be regenerated at ambient temperature.In comparison,an adsorbent loading trialkylamine can be regenerated at ambient temperature even in the presence of water with fairly good stability.
基金supported by the Ministry of Science and Technology of China (No. 2010CB732304)the Science and Technology Department of Zhejiang Province Project (No. 2011C31010)the National Natural Science Foundation of China (No. 51202126)
文摘A MnOx-NbOx-CeO2 catalyst for low temperature selective catalytic reduction（SCR） of NOx with NH3 was prepared by a sol-gel method, and characterized by NH3-NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, NOx/NH3 TPD, XRD, BET, H2-TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy（DRIFTS）. The results indicate that the Mn Ox-Nb Ox-CeO2 catalyst shows excellent low temperature NH3-SCR activity in the temperature range of 150-300℃. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NOx adsorption. As the NO2 content increases in the feed, water vapor does not affect the activity in NO2 SCR. Meanwhile, water vapor significantly enhances the N2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH4NO3 into N2O.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.51872035 and 22078052)the Innovation Program of Dalian City of Liaoning Province(No.2019RJ03)。
文摘The water promotion effects,where water can provide a solution-mediated reaction pathway in various heterogeneous chemical catalysis,have been presented and attracted wide attention recently,yet,the rational design of catalysts with a certain ability of enhancing water-induced reaction process is full of challenges and difficulties.Here,we show that by incorporating alkali(Na,K)cations as an electronic and/or structural promoter into Pd/rGO-ZnCr_(2)O_(4)(r GO,reduced graphene oxide),the obtained Pd(Na)/rGO-ZnCr_(2)O_(4)as a representative example demonstrates an outstanding benzyl alcohol oxidation activity in the Pickering emulsion system in comparison to the alkali-free counterpart.The response experiments of water injection confirm the enhanced activity,and the Na-modified catalyst can further enhance the promotion effects of water on the reaction.The effects of alkali cations for Pd nanoparticles are identified and deciphered by a series of experimental characterizations(XPS,in situ CO-DRIFTS,and CO-TPR coupled with MS),showing that there is abundant-OH on the surface of the catalyst,which is stabilized by the formation of Pd-OH_(x).The alkali-stabilized Pd-OH_(x)is helpful to enhance the waterinduced reaction process.According to the results of in situ Raman as well as UV-vis absorption spectra,the Na-modulated Pd(Na)/rGO-ZnCr_(2)O_(4)enables the beneficial characteristics for distorting the benzyl alcohol structure and enhancing the adsorption of benzyl alcohol.Further,the mechanism for enhanced water promotion effects is rationally proposed.The strategy of alkali cations-modified catalysts can provide a new direction to effectively enhance the chemical reaction involving small molecule water.
基金Project supported by the National Natural Science Foundation of China
文摘The preparation of conducting PPQ film was first reported in the previous paper. It is very interesting that this film is highly sensitive to moisture in air. The hydration and dehydration of the film are accompanied by change not only in color but also in conductivity and UV-visible spectrum. The conducting PPQ is reduced to PPQ and loses its conductivity after being soaked in water.
基金the National Natural Science Foundation of China(Grant Nos.11974385 and 91956101)the Fund from the Chinese Academy of Sciences(Grant No.1731300500030)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB07030100).
文摘Transport properties and the associated structural heterogeneity of room temperature aqueous ionic liquids and especially of super-concentrated electrolyte aqueous solutions have received increasing attention,due to their potential application in ionic battery.This paper briefly reviews the results reported mainly since 2010 about the liquid-liquid separation,aggregation of polar and apolar domains in neat RTILs,and solvent clusters and 3D networks chiefly constructed by anions in super-concentrated electrolyte solutions.At the same time,the dominating effect of desolvation process of metal ions at electrode/electrolyte interface upon the transport of metal ions is stressed.This paper also presents the current understanding of how water affects the anion-cation interaction,structural heterogeneities,the structure of primary coordination sheath of metal ions and consequently their transport properties in free water-poor electrolytes.
文摘1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water surface for an extended period.With the emergence of cross-media rotorcraft, rotor wakes interact violently with the water surface to generate large-scale,air–water droplet mixed flows (hereafter referred to as mixed air–water flows). Rotors operating in mixed air–water flows always have aerodynamic performances that are different from those owing to the In-Ground Effect (IGE) and Out-of Ground Effect (OGE). Accordingly, this effect is called the Near-Water Effect (NWE) of the rotor2,and it usually causes thrust loss and torque increase.
基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(No.KYCX24_0532)the Key Laboratory of Cross-Domain Flight Interdisciplinary Technology,China(Nos.2024-KF03001,2024-KF03003)the National Natural Science Foundation of China(No.12272169)for the financial support。
文摘Blending the agility of aerial drones with the covert capabilities of underwater submersibles,the aerial-aquatic rotorcraft has garnered substantial interest due to their unparalleled capacity to traverse both air and water.Nevertheless,a critical hurdle for these vehicles lies in mitigating the adverse effects of repeatedly transitioning between these environments,particularly during water-surface takeoffs.Currently,research on the interference caused by rotors approaching water surfaces remains limited.This paper introduces a novel adaptive rotor aerodynamic model based on continuous finite vortex theory to predict rotor thrust within gas–liquid flow field.Initially,the model's sensitivity to system parameters was analyzed to optimize its predictive capabilities.Subsequently,a comprehensive ground/water experimental setup was designed to investigate the intricate aerodynamic interactions between the rotor flow field and water.By varying rotor sizes,the characteristics of the rotor flow field and water surface were examined at different rotor-water surface distances.The performance of different modeling methods was analyzed based on the rotor experimental data of a diameter of 0.38 m,and the prediction results were quantified using the percentage of the mean-square error.The results show that the average error of the finite vortex rotor model is the smallest.Finally,a novel transition boundary is proposed to divide the rotor flow field of the gas–liquid mixture into two stages.The thrust loss zone is defined to delineate the safe operating range of the aircraft,providing a basis for the design of aerial-aquatic rotorcraft.
基金Project supported by the National Basic Research Program of China (2010CB732300)the National Key Technologies R&D Program of China (2007BAJ03B01)the National Natural Science Foundation of China (20601008)
文摘CeO2-MOx (M=Cu, Mn, Fe, Co, and Ni) mixed oxide catalysts were prepared by a citric acid complexation-combustion method. CeO2-MOx solid solutions could be formed with M cations doping into CeO2 lattice, while NiO and Co3O4 phases were detected on the surface of CeO2-NiO and CeO2-Co3O4 by Raman spectroscopy. The presence of M in CeO2 could obviously promote its catalytic activity for CH4 catalytic combustion and CO oxidation. Among the prepared samples, CeO2-CuO exhibited the best performance for CO oxidatio...
基金financially supported by the National Natural Science Foundation of China (No.51504084)the Education Department of Fujian Province (No.JA15493)
文摘To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experiments were used to validate the effects of using surfactants;the results show that after dealing with vacuum saturation with water,the volume of micropores decreases,which results in a larger average pore size,and the volume of transitional pores,mesopores,macropores and total pores increases.Based on the distribution of pore size,the operation mode of ‘‘water infusion after gas extraction,then continuing gas extraction" is recommended to improve the volume of coal mine gas drainage.When the reflectance of vitrinite in coal samples is less than 1,using the surfactants Fast T,1631,APG,BS can mitigate the damage caused by the water blocking effect.But when the reflectance of vitrinite is larger than 1.4,the damage caused by the water blocking effect can be increased.When the surfactant CMC is used in hydraulic applications,the capillary forces of coal samples are almost negative,which means the capillary force is in the same direction as the gas extraction.The direction of capillary forces benefits the gas flow.So,using CMC can play an active role in removing the water blocking effect.Centrifugal experiments confirm that using CMC can effectively remove the water blocking effect,which has a beneficial effect on improving the gas drainage volume.
基金supported by a cooperation agreement between Yamaguchi University and the Ministry of Education & Training (Vietnam)
文摘The inactivation effects of pressurized CO2 against bacteriophage Qβ and ФX 174 were investigated under the pressure of 0.3-0.9 MPa, initial concentration of 107-109 PFU/mL, and temperature of 17.8℃-27.2℃. The optimum conditions were found to be 0.7 MPa and an exposure time of 25 min. Under identical treatment conditions, a greater than 3.3-log reduction in bacteriophage Qβ was achieved by CO2, while a nearly 3.0 log reduction was observed for phage ФX174. The viricidal effects of N2O （an inactivation gas with similar characteristics to CO2）, normal acid （HC1）, and CO2 treatment with phosphate buffered saline affirmed the chemical nature of CO2 treatment. The pumping cycle, depressurization rate, and release of intracellular substances caused by CO2 were its viricidal mechanisms. The results indicate that CO2 has the potential for use as a disinfectant without forming disinfection by-products.
文摘The water effect on peroxy radical measurement by chemical amplification was determined experimentally for HO2 and HO2+OH, respectively at room temperature (298±2) K and atmospheric pressure (1×105 Pa). No significant difference in water effect was observed with the type of radicals. A theoretical study of the reaction of HO2·H2O adduct with NO was performed using density functional theory at CCSD(T)/6-311 G(2d, 2p)//B3LYP/6-311 G(2d, 2p) level of theory. It was found that the primary reaction channel for the reaction is HO2·H2O+NO→HNO3+H2O (R4a). On the basis of the theoretical study, the rate constant for (R4a) was calculated using Polyrate Version 8.02 program. The fitted Arrenhnius equation for (R4a) is k = 5.49×107 T 1.03exp(?14798/T) between 200 and 2000 K. A chemical model incorporated with (R4a) was used to simulate the water effect. The water effect curve obtained by the model is in accordance with that of the experiment, suggesting that the water effect is probably caused mainly by (R4a).
基金Funded by the National Basic Research Program of China(No.2009CB623200)Zhejiang Natural Science Foundation(No.LQ12E08002)+1 种基金Ningbo Natural Science Foundation(No.2012A610159)the School Disciplinary Projects(No.zj1113,XKL11D2081)
文摘The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on water loss ratio were consistent with those on drying shrinkage strain. It is also indicated that drying shrinkage strain has obvious linear correlation with water loss ratios independent of specimen size and shape. The effects of specimen size and shape on the water loss ratio were embodied in established model of averaged relative humidity improved by considering effects of sequential hydration and calculated by finite difference method. Furthermore, the effects of specimen size and shape on drying shrinkage strain of concrete were experimentally deduced and applied to modify criterion EB-FIP1990. The comparison between experimental and calculated results shows that the modified EB-FIP1990 can be adopted to predict drying shrinkage strain of concrete with reasonable accuracy.
文摘Soybean cultivar Bei 92-28 was tested in this experiment in 2000 to study the coupling effect of water and ferilizer on soybean yield.The results showed that the effect of irrigation varied among the levels of fertilizer application,and vice versa;pods per plant,seeds per pod.and 100-seed weight had positive correlations with soybean yield,but the degrees of correlations of different treatments were various;LAI and dry matter accumulation could be significantly increased when watered and applied fertilizer with different levels,but high fertilizer application treatment didn't obtain the highest yield;watering could increase the absolute absorption amount of N,P,K in seeds,but the accumulation rates were various.
基金Supported by the Fund from Shenzhen Techand Econology&Environment Co.,Ltd.(THRD004)
文摘The Microcystis sample was selected from natural bloom water,then the algicidal effects of the bacterial strain fluid of the two algicidal bacteria,supernatant and bacterial liquid were studied. Moreover,the changes of microalgae colony and morphology in the process of algae-lysing were observed using neutral red staining and scanning electron microscope. It showed that AA06 bacteria had certain algicidal effect while AA10 bacteria had no effect. All the supernatants of the two bacterial strains had obvious algicidal effects,and the algicidal effects between the bacterial liquid and supernatant had no significant differences( P < 0. 05). The effects of algae-lysing mainly owed to the chemical substances secreted by algicidal bacteria. During the algae-lysing process,the algae colony did not disperse into individual cells. The segments of the dead cells still aggregated together.
基金supported by the National Key Research and Development Program of China(No.2016YFC0400706)the National Natural Science Foundation of China(No.51778521)the Shaanxi Science Fund for Distinguished Young Scholars(No.2018JC-026)
文摘Manganese and ammonium pollution in surface water sources has become a serious issue.In this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simultaneous removal of ammonium and manganese from surface water using a manganese co-oxide filter film(MeO_x ). The results showed that the manganese removal efficiency of MeO_x in the absence of ammonium was high and stable, and the removal efficiency could reach 70% even at 5.5 °C. When the influent ammonium concentration was lower than 0.7 mg/L, ammonium and manganese could be removed simultaneously. However, at an ammonium concentration of 1.5 mg/L, the manganese removal efficiency of the filter gradually decreased with time(from 96% to 46.20%). Nevertheless, there was no impact of manganese on ammonium removal. The mechanism by which ammonium negatively affected manganese removal was investigated, demonstrating that ammonium affected manganese removal mainly through two possible mechanisms. On one hand, the decreased p H caused by ammonium oxidation was unfavorable for the oxidation of manganese by MeO_x ; on the other hand, the presence of ammonium slowed the growth of new MeO_x and retarded the increase in the specific surface area of the Me Ox-coated sand, and induced changes in the morphology and crystal structure of Me Ox. Consequently, the manganese removal efficiency of the filter decreased when ammonium was present in the inlet water.
基金supported jointly by the National Knowledge Innovation Pro-gram of the Chinese Academy of Sciences (KZCX2-YW-102)the National Natural Science Foundation of China (40525011, 40632011)
文摘Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). However, the conformational change of DOM resultant from water chemistry and concentrations of DOM was not extensively investigated; therefore, the contradictory reports regarding the binding property with HOCs were available in literature. In this study, the effects of ionic strength, pH and DOM concentrations on the fluorescence properties of two humic acids (HA), namely Fluka HA and Amherst HA, were investigated by three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) and steady-state fluorescence polarization (FP) techniques. The results not only corroborated previous observations obtained by other investigators, but revealed some new information about the fluorescence properties and molecular conformation of the humic acids under different water chemistry and DOM concentration conditions, which could shed light on its binding mechanisms and binding properties with HOCs.
基金Supported by the National Natural Science Foundation of China(41571415,41071281)Natural Science Foundation of Jiangsu Province(BK20131078)Planning Project for Cultivation of Young Academic Leaders in"Qinglan Project"of Education Department of Jiangsu Province
文摘Based on the observation data of rainfall,vegetation,runoff and sediment yield in the experimental plots located in Hetian Town,Changting County of Fujian Province during 2007-2010,the changing characteristics and interrelation of live vegetation volume of grass,rainfall parameters,and water(soil)conservation effect RE(SE)were analyzed at four time scales of rainfall event,month,season,and year.The results showed that with the increase of time scales,the rainfall and vegetation indicators increased or decreased more or less,and the variation range of RE was small,while SEslowly decreased.The mean REchanged by 10%-20% at different time scales,and the observed water conservation effect of the grassland was the best at season scale while the worst at year scale.The soil conservation effect of the grassland was the best at month scale and the worst at season scale.The water conservation effect of the grass was mainly controlled by rainfall factors,including rainfall duration and precipitation at rainfall event scale,and the maximum intensity of precipitation within 30 min at longer time scales.However,the soil conservation effect of the grass was mainly controlled by vegetation factors,including the contribution of the litter on soil surface at rainfall event scale,the interaction of rainfall and vegetation at month and season scales,and the live vegetation volume of the grass at year scale.Consequently,at different time scales,the factors influencing water and soil conservation changed and interacted,and the observed water and soil conservation effects were also different,indicating that the influence of time scales deserves attention in both research and management practices.
基金the School of Environment,Griffith University,for providing Ph.D.scholarship and funding for J.H
文摘Ammonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ammonium pollution comes from diffuse agricultural sources, making control difficult, industrial or municipal point sources such as wastewater treatment plants also contribute significantly to overall ammonium pollution.These latter sources can be targeted more readily to control ammonium release into water systems. To assist policy makers and researchers in understanding the diversity of treatment options and the best option for their circumstance, this paper produces a comprehensive review of existing treatment options for ammonium removal with a particular focus on those technologies which offer the highest rates of removal and cost-effectiveness. Ion exchange and adsorption material methods are simple to apply, cost-effective, environmentally friendly technologies which are quite efficient at removing ammonium from treated water. The review presents a list of adsorbents from the literature, their adsorption capacities and other parameters needed for ammonium removal. Further, the preparation of adsorbents with high ammonium removal capacities and new adsorbents is discussed in the context of their relative cost, removal efficiencies, and limitations. Efficient, cost-effective, and environmental friendly adsorbents for the removal of ammonium on a large scale for commercial or water treatment plants are provided. In addition, future perspectives on removing ammonium using adsorbents are presented.
基金Supported by the National Nature Science Foundation of China under Grant Nos 11434012 and 11174312
文摘A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the broadband signals. It is observed that the transmission loss （TL） decreases up to 7 dB for the signals in the first shadow zone due to the seamount reflection. Moreover, the TL might increase more than 30 dB in the converge zone due to the shadowing by seamounts. Abnormal TLs and pulse arrival structures at different ranges are explained by using the ray and wave theory. The experimental TLs and arrival pulses are compared with the numerical results and found to be in good agreement.
基金financially supported by the National Nature Science Foundation of China (No.50490271)the National Key Technologies R & D Program of China (No.2004BA615A-18).
文摘The functioning mechanism of groundwater and its make-up water in the process of ground subsidence was studied from such three aspects as osmotic corrasion, osmotic pressure effect and concretion effect, As to osmotic corrasion, its forming conditions, mechanical mechanism and process were analyzed, As to osmotic pressure effect, it was mainly studied from hydrostatic pressurizing effect, sop softening effect and negative pressure sealing effect. Through concretion and saturation of soil, the factors of concretion settlement were analyzed. The results showed that both groundwater and its make-up water are important triggering factors to ground subsidence.
