Fuzzy mathematics comprehensive evaluation method is used to evaluate the geological environment suitability of rural urbanization in Qingdao City,China.A total of 5 first-level evaluation factors are selected,includi...Fuzzy mathematics comprehensive evaluation method is used to evaluate the geological environment suitability of rural urbanization in Qingdao City,China.A total of 5 first-level evaluation factors are selected,including environmental geological condition,geological resources,engineering geological condition,geological disaster and environmental geological problem,and human engineering activity.And there are 27 second-level evaluation factors,such as topography,land type and vegetation,nature reserve,water source protection area,groundwater quality division,and major engineering project.Qingdao City is divided into four districts of suitable area,relatively suitable area,moderately suitable area and relatively unsuitable area of ecological environment.And their characteristics are introduced.Suggestions for the developing direction of urban construction are put forward.Region of Laoshan District lying to the west of the Shilaoren is suitable to set up high-rise building;west Hongshiya may establish a waste landfill site;Jiaozhou Bay,the downstream of Dagu River,and Jihongtan Reservoir should be built as the key geological environment protection area and water source protection area.And the north Hongdao should be strictly monitored in order to control the expansion of urban construction to Jihongtan Reservoir.Mocheng District and the area north of it,Jiaozhou District and the area east of it are the ideal urban construction development areas in Qingdao City in the future.展开更多
Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010.The COMS OLR retrieval algorithms are based o...Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010.The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels.This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm (OLR12.0 using the 12.0 μm channel) and three multiple-channel algorithms (OLR10.8+12.0 using the 10.8 and 12.0 pm channels; OLR6.7+10.8 using the 6.7 and 10.8 μm channels; and OLRAll using the 6.7,10.8,and 12.0 μm channels).The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth's Radiant Energy System (CERES) over the full COMS field of view [roughly (50°S-50°N,70°-170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5-7 W m-2,which indicates good agreement with CERES OLR over the vast domain.OLR6.7+10.8 and OLRAll have much smaller errors (~ 6 W m-2) than OLR12.0 and OLR10.8+12.0 (~ 8 W m-2).Moreover,the small errors of OLR6.7+10.8 and OLRAll are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration.These results indicate a noteworthy role of the 6.7 μm water vapor absorption channel in improving the accuracy of the OLRs.The dependence of the accuracy of COMS OLRs on various surface,atmospheric,and observational conditions is also discussed.展开更多
Use of ultraporous nylon membrane is one of the most widely employed techniques for removal of hard and soft nanoparticles in the semiconductor industry, and the accurate determination of membrane pore size is necessa...Use of ultraporous nylon membrane is one of the most widely employed techniques for removal of hard and soft nanoparticles in the semiconductor industry, and the accurate determination of membrane pore size is necessary in order to avoid manufacturing defects caused by contamination. The gold nanoparticle has several benefits for the evaluation of polymeric membranes; however, the nanoparticles agglomerate easily on the nylon membrane and make it difficult to evaluate the membrane precisely. The properties of 2-amino-2-hydroxymethyl-1,3-propanediol(ADP) ligand in gold nanoparticle solution were systematically investigated, and ADP was utilized for improved evaluation of the nylon membranes. Nylon membrane used in this study was prepared by phase inversion techniques. Ultrathin dense layer on top of the membrane surface and Darcy structures in the microporous membrane support were observed. The gold particle rejection was carried out at various p H values from 4 to14 and higher rejection was observed at p H 4 and 8. The suppression of gold colloid agglomeration using ADP and monodispersity of gold colloids was also analyzed by confocal laser scanning microscopy(CLSM), transmission electron microscopy(TEM), and scanning electron microscopy(SEM). van der Waals interaction energy of the particles was reduced in the addition of ADP. The presence of ADP ligand in the gold solutions prevented the agglomeration of gold nanoparticles and reduced the adsorption of the particles on the nylon membrane surface,leading to precise evaluation of membrane pore sizes.展开更多
In order to study the thermoelectric properties of TiO2-based hybrid materials, TiO2/polyparaphenylene(PPP)nanocomposites are fabricated by spark plasma sintering(SPS). The results show that the electrical conduct...In order to study the thermoelectric properties of TiO2-based hybrid materials, TiO2/polyparaphenylene(PPP)nanocomposites are fabricated by spark plasma sintering(SPS). The results show that the electrical conductivity follow percolation theory is enhanced due to the electron transfer highway provided by the conducting PPP phase. Furthermore,the thermal conductivity is reduced due to the drastic difference of vibrational spectra between organic and inorganic components. As a result, the greatest ZT= 0.24 is obtained for Ti O2/0.75 wt% PPP sample, which is 15-fold higher than pure Ti O2(ZT= 0.016).展开更多
A dimeric coordination complex Cd2(ncpo)2(phen)2(H2O)2 was constructed by a flexible dicarboxylic acid, 2-nitro-4-carboxylphenoxyacetic acid. Its crystal structure was determined by X-ray single-crystal diffract...A dimeric coordination complex Cd2(ncpo)2(phen)2(H2O)2 was constructed by a flexible dicarboxylic acid, 2-nitro-4-carboxylphenoxyacetic acid. Its crystal structure was determined by X-ray single-crystal diffraction analysis. The crystal is of monoclinic system, space group P21/n with a = 17.2616(3), b = 12.7460(2), c = 18.4041(3) A^°, β= 94.432(1)°, C42H30Cd2N6O16, Mr = 1099.52, V = 4037.09(12)A^°^3 Dc = 1.809 g/cm^3, F(000) = 2192, μ = 1.139 cm^-1 and Z = 4. The final R = 0.0218 and wR = 0.0703 for 8288 observed reflections with I 〉 2σ(I). There are two crystallographically independent but structurally very similar molecules in the unit cell of the title complex. It is noticeable that the ligand ncpo^2- displays a good flexibility, demonstrating different modes from the rigid ligands. The luminescence property has been investigated, which shows photoluminescence at 465, 490 and 574 nm upon excitation at 320 nm in the solid state at room temperature.展开更多
Biogas from renewable sources and natural gas(NG) are both high-efficient and good-quality gaseous fuels on account of their enrichment in methane. Due to the dissimilar physical properties of biogas and NG, biogas ca...Biogas from renewable sources and natural gas(NG) are both high-efficient and good-quality gaseous fuels on account of their enrichment in methane. Due to the dissimilar physical properties of biogas and NG, biogas cannot substitute NG directly without treatment and is usually used on site due to the high cost of the transportation and distribution via exclusive pipeline system. Consequently, the injection of biogas into existing NG infrastructure was proposed to address the deficiency. In this paper, the Wobbe index (WI) as well as the combustion potential (CP) were introduced for analyzing the interchangeability of an NGbiogas mixture, and a mathematical framework was put forward for modeling and simulating NG grid with a decentralized biogas injection. Results show that the maximum admissible amount of biogas in mixture was 10.5% by volume. A medium pressure network was used to interrogate the comprehensive effect of distributed biogas injection, which showed an impact on both gas quality and hydraulic regime across the grid.展开更多
Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed e...Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed external radiative forcing for 1850-2005, and their future changes in the RCP(Representative Concentration Pathway) 4.5 scenario runs for2006-2100. Validation metrics for the historical run are designed to examine the accuracy in the representation of spatial patterns for climatological mean, and annual and interannual variations of clouds and CREs. The models show large spread in the simulation of cloud amounts, specifically in the low cloud amount. The observed relationship between cloud amount and the controlling large-scale environment are also reproduced diversely by various models. Based on the validation metrics,four models-ACCESS1.0, ACCESS1.3, Had GEM2-CC, and Had GEM2-ES-are selected as best models, and the average of the four models performs more skillfully than the multimodel ensemble average.All models project global-mean SST warming at the increase of the greenhouse gases, but the magnitude varies across the simulations between 1 and 2 K, which is largely attributable to the difference in the change of cloud amount and distribution. The models that simulate more SST warming show a greater increase in the net CRE due to reduced low cloud and increased incoming shortwave radiation, particularly over the regions of marine boundary layer in the subtropics. Selected best-performing models project a significant reduction in global-mean cloud amount of about-0.99% K^-1and net radiative warming of 0.46 W m^-2K^-1, suggesting a role of positive feedback to global warming.展开更多
Assembling MnO_(2)nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity,yet its development is limited by the deficiencies in...Assembling MnO_(2)nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity,yet its development is limited by the deficiencies in preparation and property modulation of the MnO_(2)nanowires.In this work,we developed a facile method using C_(2)H_5OH and CH_(3)COOK as reductive and vital control reagents to react with KMnO_(4)by hydrothermal reaction at 140℃for 12 h,to prepare the ultralongα-MnO_(2)nanowires up to tens of micrometers with high purity and aspect ratio.Such strategy not only had the advantages of being mild,easily controlled and environmental pollution-free,but also endowedα-MnO_(2)nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds(k_(obs)=0.0738~0.1695 min^(-1))in a continuous flow reaction.The reactive oxygen species(i.e.,~·OH)from Fenton-like reaction were enriched within thisα-MnO_(2)nanowire membrane via nanoconfinement effect,which further enhanced the mass transportation of~·OH available for phenolic contaminants.MnO_(2)nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances.展开更多
Oleylamine (G18) and octanol (G8) were grafted onto the surfaces of the multi-walled carbon nanotubes (CNTs). The grafted CNTs were dispersed into palmitic acid (PA) and paraffin wax (PW) to prepare phase ch...Oleylamine (G18) and octanol (G8) were grafted onto the surfaces of the multi-walled carbon nanotubes (CNTs). The grafted CNTs were dispersed into palmitic acid (PA) and paraffin wax (PW) to prepare phase change composites. The heat storage/retrieval experiments showed that the composites kept stable after repeating melting and solidification for 80 times. The structure of the G18-CNT/PA and G8-CNT/PA was homogenous compared with the pristine CNT (P-CNT)/PA. The latent heat capacity (Ls) of solid liquid phase change of G18-CNT/PW was higher than that of PW while those of the G8-CNTI/PW and P-CNT/PW were lower than that of PW. Compared with PA, all PA based composites with both P-CNTs and grafted CNTs decreased Ls evidently. The Ls values of GI8-CNT composites in both matrices were higher than that of the counterparts of G8-CNT. The thermal conductivities of all the PA based composites in the study were higher than that of PA, as well as those of all the PW based composites. However, the thermal conductivities of the GI8-CNT composites in both matrixes were lower than those of the G8-CNT composites in both matrixes at all measured temperatures.展开更多
Aluminum nitride nanoparticles (AINs) have been found to be a good additive for enhancing the thermal conductivity of traditional heat exchange fluids. At a volume fraction of 0.1, the thermal conductivity enhanceme...Aluminum nitride nanoparticles (AINs) have been found to be a good additive for enhancing the thermal conductivity of traditional heat exchange fluids. At a volume fraction of 0.1, the thermal conductivity enhancement ratios are 38.71% and 40.2%, respectively, for ethylene glycol and propylene glycol as the base fluids. Temperature does not have much influence on the enhanced thermal conductivity ratios of the nanofluids, though a volume fraction of 5.0% appears to signify a critical concentration for rheology: for 〈5.0vo1% for Newtonian behavior, and for 〉5.0vo1% for obvious shear-shinning behavior, for both ethylene glycol and propylene glycol.展开更多
This study presents the results obtained from magnetic susceptibility and heavy metal (Cu, Zn, Pb, and Cr) concentration measurements of soil profiles collected from arable land and urban parks in Baoshan District, ...This study presents the results obtained from magnetic susceptibility and heavy metal (Cu, Zn, Pb, and Cr) concentration measurements of soil profiles collected from arable land and urban parks in Baoshan District, an industrial district of Shanghai, China. The study focuses on the investigation of vertical variations in magnetic susceptibilities and heavy metal concentrations and on correlations between magnetic susceptibilities and heavy metal concentrations in soil profiles. The results demon- strate that magnetic enhancement in the surface layer of the soil profile is associated with increased heavy metal pollution. The enrichment factors (EF) and the Tomlinson Pollution Load Index (PLI-EF) are calculated for estimat- ing the level of heavy metal pollution of soil profiles in the study. The significant positive correlations between heavy metal contents, enrichment factors (EF), Tomlinson pollution load index (PLI-CF), modified Tomlinson pollution load index (PLI-EF), and magnetic susceptibility (X) indicate that much of the heavy metal contamination in the study area is linked to combustion derived particulate emissions. The results confirm that the combined magnetic measurement and heavy metal concentration analysis could provide useful information for soil monitoring in urban environments. However, the use of magnetic technique to locate the heavy metal pollution boundary in the soil profile of this studied area should be confirmed by further geochemical analysis.展开更多
Anaerobic digestion (AD) is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Des...Anaerobic digestion (AD) is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination: denaturing gradient gel electrophoresis (DGGE) and real-time polymerase chain reaction (PCR). Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group (〉 94% of the total methanogen population) in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.展开更多
Synthesis of TiO2 nanoparticles by the oxidation of titanium tetrachloride (TiCI4) in high-strength propane/air turbulent flame is investigated tentatively for mass production of TiO2 nanoparticles. Effects of react...Synthesis of TiO2 nanoparticles by the oxidation of titanium tetrachloride (TiCI4) in high-strength propane/air turbulent flame is investigated tentatively for mass production of TiO2 nanoparticles. Effects of reactor heat flux varying from 247 to 627 kJ/m^2 s, initial TiO2 number density from 2 × 10^20 to 1 × 10^21 m^ 3, and apparent residence time of TiO2 nanoparticles in reactor from 0.06 to 0.9 s, on particle morphology, phase composition, UV absorption and photoluminescence (PL) spectra are studied. The TiO2 nanoparticles synthesized, with mean size of 30-80 nm and futile mass fraction from 0.155 up to 0.575, exhibited a strong PL signal at the wavelength of 370-450 nm, with a wide peak signal at 400-420 nm, reflecting significant oxygen vacancies on the surface of the TiO2 nanoparticles.展开更多
Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process mi...Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen(T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models-artificial neural networks(ANNs) and support vector machines(SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination(R^2), Nash-Sutcliff efficiency(NSE), relative efficiency criteria(d rel). Additionally, Latin-Hypercube one-factor-at-a-time(LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage.However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process.展开更多
Photodegradation of benzene at ppb levels by mixed-phase TiO2 nanoparticles, synthesized by the oxidation of TiCl4 in propane/air turbulent flame chemical vapor deposition (CVD) process, is investigated experimental...Photodegradation of benzene at ppb levels by mixed-phase TiO2 nanoparticles, synthesized by the oxidation of TiCl4 in propane/air turbulent flame chemical vapor deposition (CVD) process, is investigated experimentally by using a tubular photoreactor with thin TiO2 films coated on the reactor wall by sedimentation. Effects of inlet benzene concentration from 10 to 300μg/m3, rutile mass fraction from about 20 to 50% and photoluminescence (PL) intensity of TiO2 nanoparticles on degradation degree are examined under the conditions of 70% relative humidity, 38 μg/cm2 catalyst loading, 24mW/cm2 UV irradiation of 254 nm and 5.7 s residence time in the reactor. Based on experimental results, separation of photoinduced electron (e-) and hole (h+) pairs by rutile phase is discussed as photo-induced electron (e-) in anatase phase will migrate to rutile surface due to that the potential of conductive band of rutile is lower than that of anatase, leading to more holes ready on anatase surface for oxidation reactions.展开更多
Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and no...Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and non-Ohmic resistances as well as the performance of RED were systematically studied by using in situ electrochemical impedance spectroscopy(EIS).Three different parameters(membrane type,number of cell pairs and spacer design)were controlled.The Ohmic and non-Ohmic resistances were evaluated for RED stacks equipped with two types of commercial membranes(Type I and Type II)supplied by Fujifilm Manufacturing Europe B.V:Type I Fuji membranes displayed higher Ohmic and non-Ohmic resistances than Type II membranes,which was mainly attributed to the difference in fixed charge density.The output power of the stack was observed to decrease with the increasing number of cell pairs mainly due to the increase in ionic shortcut currents.With the reduction in spacer thickness from 750 to 200μm,the permselectivity of membranes in the stack decreased from 0.86 to 0.79 whereas the energy efificiency losses increased from 31%to 49%.Overall,the output of the present study provides a basis for understanding the impact of stack design on internal losses during the scaling-up of RED.展开更多
Wind power systems have gained much attention due to the relatively high reliability, maturity in technology and cost competitiveness compared to other renewable alternatives. Advances have been made to increase the p...Wind power systems have gained much attention due to the relatively high reliability, maturity in technology and cost competitiveness compared to other renewable alternatives. Advances have been made to increase the power efficiency of the wind turbines while less attention has been focused on structural integrity assessment of the structural systems. Vibration-based damage detection has widely been researched to identify damages on a structure based on change in d^mmic characteristics. Widely spread methods are natural frequency-based, mode shape-based, and curvature mode shape-based methods. The natural frequency-based methods are convenient but vulnerable to environmental temperature variation which degrades damage detection capability; mode shapes are less influenced by temperature variation and able to locate damage but requires extensive sensor instrumentation which is costly and vulnerable to signal noises. This study proposes novelty of damage factor based on sensor fusion to exclude effect of temperature variation. The combined use of an accelerometer and an inclinometer was considered and damage factor was defined as a change in relationship between those two measurements. The advantages of the proposed method are: 1) requirement of small number of sensor, 2) robusmess to change in temperature and signal noise and 3) ability to roughly locate damage. Validation of the proposed method is carried out through numerical simulation on a simplified 5 MW wind turbine model.展开更多
Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between ...Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between bubbles and the dense phase was determined by kbe = 0.21 db. A theoretical analysis of the mass transfer coefficient between a bubble and the dense phase using diffusion equations showed that the mass transfer coefficient between a bubble and the dense phase is kbe α εmf√ub/db in both three- and two-dimensional fiuidized beds. An effective diffusion coefficient in gas fluidized beds was introduced and correlated with bubble size as De = 13.3db2.7 for Group A and Group B particles. The mass transfer coefficient kbe can then be expressed as kbe = 0.492εmf√ubdb1.7 for bubbles in a three-dimensional bed and kbe = 0.576εm√ubdb1.7 for bubbles in a two-dimensional bed.展开更多
The capture of orthophosphates and total phosphorus from the Pudong Canal river in the Pudong District of Shanghai by TiO2 nanoparticles is studied using a rotating photoreactor and the nano-TiO2 photocatalyst Degussa...The capture of orthophosphates and total phosphorus from the Pudong Canal river in the Pudong District of Shanghai by TiO2 nanoparticles is studied using a rotating photoreactor and the nano-TiO2 photocatalyst Degussa P25. The effects of UV irradiation intensity in a range of 20-74 mW/cm^2, the loading of the TiO2 nanoparticles in a range of 0.05-0.1 g/L, irradiation time up to 4 h, and pH values in a range of 2-10.5 on the capture efficiency are investigated. The results show that the capture of orthophosphates and total P are significantly enhanced by UV irradiation; at a loading of 0.1 g/L and an irradiation intensity above 36 mW/cm^2, orthophosphates and total phosphorus are rapidly captured by TiO2 nanoparticles, causing an observed reduction from 0.4 mg/L down to 0.02 mg/L. pH values in a range of 2-10.5 have little effect on the capture efficiency of orthophosphates and total phosphorus.展开更多
文摘Fuzzy mathematics comprehensive evaluation method is used to evaluate the geological environment suitability of rural urbanization in Qingdao City,China.A total of 5 first-level evaluation factors are selected,including environmental geological condition,geological resources,engineering geological condition,geological disaster and environmental geological problem,and human engineering activity.And there are 27 second-level evaluation factors,such as topography,land type and vegetation,nature reserve,water source protection area,groundwater quality division,and major engineering project.Qingdao City is divided into four districts of suitable area,relatively suitable area,moderately suitable area and relatively unsuitable area of ecological environment.And their characteristics are introduced.Suggestions for the developing direction of urban construction are put forward.Region of Laoshan District lying to the west of the Shilaoren is suitable to set up high-rise building;west Hongshiya may establish a waste landfill site;Jiaozhou Bay,the downstream of Dagu River,and Jihongtan Reservoir should be built as the key geological environment protection area and water source protection area.And the north Hongdao should be strictly monitored in order to control the expansion of urban construction to Jihongtan Reservoir.Mocheng District and the area north of it,Jiaozhou District and the area east of it are the ideal urban construction development areas in Qingdao City in the future.
基金supported by the Korea Meteorological Administration Research and Development Program (Grant No. CATER 2012-2040)
文摘Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010.The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels.This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm (OLR12.0 using the 12.0 μm channel) and three multiple-channel algorithms (OLR10.8+12.0 using the 10.8 and 12.0 pm channels; OLR6.7+10.8 using the 6.7 and 10.8 μm channels; and OLRAll using the 6.7,10.8,and 12.0 μm channels).The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth's Radiant Energy System (CERES) over the full COMS field of view [roughly (50°S-50°N,70°-170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5-7 W m-2,which indicates good agreement with CERES OLR over the vast domain.OLR6.7+10.8 and OLRAll have much smaller errors (~ 6 W m-2) than OLR12.0 and OLR10.8+12.0 (~ 8 W m-2).Moreover,the small errors of OLR6.7+10.8 and OLRAll are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration.These results indicate a noteworthy role of the 6.7 μm water vapor absorption channel in improving the accuracy of the OLRs.The dependence of the accuracy of COMS OLRs on various surface,atmospheric,and observational conditions is also discussed.
基金Supported by the MOTIE(Ministry of Trade,Industry and Energy)(10048995)KSRC(Korea Semiconductor Research Consortium)support program for the development of the future semiconductor devicethe KIST-UNIST Partnership Program(1.150091.01/2V04470)
文摘Use of ultraporous nylon membrane is one of the most widely employed techniques for removal of hard and soft nanoparticles in the semiconductor industry, and the accurate determination of membrane pore size is necessary in order to avoid manufacturing defects caused by contamination. The gold nanoparticle has several benefits for the evaluation of polymeric membranes; however, the nanoparticles agglomerate easily on the nylon membrane and make it difficult to evaluate the membrane precisely. The properties of 2-amino-2-hydroxymethyl-1,3-propanediol(ADP) ligand in gold nanoparticle solution were systematically investigated, and ADP was utilized for improved evaluation of the nylon membranes. Nylon membrane used in this study was prepared by phase inversion techniques. Ultrathin dense layer on top of the membrane surface and Darcy structures in the microporous membrane support were observed. The gold particle rejection was carried out at various p H values from 4 to14 and higher rejection was observed at p H 4 and 8. The suppression of gold colloid agglomeration using ADP and monodispersity of gold colloids was also analyzed by confocal laser scanning microscopy(CLSM), transmission electron microscopy(TEM), and scanning electron microscopy(SEM). van der Waals interaction energy of the particles was reduced in the addition of ADP. The presence of ADP ligand in the gold solutions prevented the agglomeration of gold nanoparticles and reduced the adsorption of the particles on the nylon membrane surface,leading to precise evaluation of membrane pore sizes.
基金supported by the National Natural Science Foundation of China(Grant No.51206103)the Innovation Program of Shanghai Municipal Education Commission,China(Grant No.13YZ128)+1 种基金the Opening Project of CAS Key Laboratory of Materials for Energy Conversion,Chinathe Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher learning,China
文摘In order to study the thermoelectric properties of TiO2-based hybrid materials, TiO2/polyparaphenylene(PPP)nanocomposites are fabricated by spark plasma sintering(SPS). The results show that the electrical conductivity follow percolation theory is enhanced due to the electron transfer highway provided by the conducting PPP phase. Furthermore,the thermal conductivity is reduced due to the drastic difference of vibrational spectra between organic and inorganic components. As a result, the greatest ZT= 0.24 is obtained for Ti O2/0.75 wt% PPP sample, which is 15-fold higher than pure Ti O2(ZT= 0.016).
基金supported by the National Natural Science Foundation of China (No. 20471008)the Excellent Young Scholars Research Fund of Beijing Institute of Technology (No. 000Y02-8)
文摘A dimeric coordination complex Cd2(ncpo)2(phen)2(H2O)2 was constructed by a flexible dicarboxylic acid, 2-nitro-4-carboxylphenoxyacetic acid. Its crystal structure was determined by X-ray single-crystal diffraction analysis. The crystal is of monoclinic system, space group P21/n with a = 17.2616(3), b = 12.7460(2), c = 18.4041(3) A^°, β= 94.432(1)°, C42H30Cd2N6O16, Mr = 1099.52, V = 4037.09(12)A^°^3 Dc = 1.809 g/cm^3, F(000) = 2192, μ = 1.139 cm^-1 and Z = 4. The final R = 0.0218 and wR = 0.0703 for 8288 observed reflections with I 〉 2σ(I). There are two crystallographically independent but structurally very similar molecules in the unit cell of the title complex. It is noticeable that the ligand ncpo^2- displays a good flexibility, demonstrating different modes from the rigid ligands. The luminescence property has been investigated, which shows photoluminescence at 465, 490 and 574 nm upon excitation at 320 nm in the solid state at room temperature.
基金Funded by China 12th Five-year Plan Key R&D Program(2013BAJ11B05)
文摘Biogas from renewable sources and natural gas(NG) are both high-efficient and good-quality gaseous fuels on account of their enrichment in methane. Due to the dissimilar physical properties of biogas and NG, biogas cannot substitute NG directly without treatment and is usually used on site due to the high cost of the transportation and distribution via exclusive pipeline system. Consequently, the injection of biogas into existing NG infrastructure was proposed to address the deficiency. In this paper, the Wobbe index (WI) as well as the combustion potential (CP) were introduced for analyzing the interchangeability of an NGbiogas mixture, and a mathematical framework was put forward for modeling and simulating NG grid with a decentralized biogas injection. Results show that the maximum admissible amount of biogas in mixture was 10.5% by volume. A medium pressure network was used to interrogate the comprehensive effect of distributed biogas injection, which showed an impact on both gas quality and hydraulic regime across the grid.
基金supported by the APEC Climate Centersupported by the UNIST research fund (Grant No. 1.09006.01)provided by a grant (Grant No. 14AWMP-B082564-01) from the Advanced Water Management Research Program funded by the Ministry of Land, Infrastructure and Transport of the Korean government
文摘Using 32 CMIP5(Coupled Model Intercomparison Project Phase 5) models, this study examines the veracity in the simulation of cloud amount and their radiative effects(CREs) in the historical run driven by observed external radiative forcing for 1850-2005, and their future changes in the RCP(Representative Concentration Pathway) 4.5 scenario runs for2006-2100. Validation metrics for the historical run are designed to examine the accuracy in the representation of spatial patterns for climatological mean, and annual and interannual variations of clouds and CREs. The models show large spread in the simulation of cloud amounts, specifically in the low cloud amount. The observed relationship between cloud amount and the controlling large-scale environment are also reproduced diversely by various models. Based on the validation metrics,four models-ACCESS1.0, ACCESS1.3, Had GEM2-CC, and Had GEM2-ES-are selected as best models, and the average of the four models performs more skillfully than the multimodel ensemble average.All models project global-mean SST warming at the increase of the greenhouse gases, but the magnitude varies across the simulations between 1 and 2 K, which is largely attributable to the difference in the change of cloud amount and distribution. The models that simulate more SST warming show a greater increase in the net CRE due to reduced low cloud and increased incoming shortwave radiation, particularly over the regions of marine boundary layer in the subtropics. Selected best-performing models project a significant reduction in global-mean cloud amount of about-0.99% K^-1and net radiative warming of 0.46 W m^-2K^-1, suggesting a role of positive feedback to global warming.
基金The support from National Natural Science Foundation of China(Nos.52000050,52100024 and 42007115)Postdoctoral Science Foundation of China(Nos.2019M663245 and 2020M670913)+1 种基金Heilongjiang Postdoctoral Fund(No.LBH-Z20063)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(Nos.2021TS22 and QAK202111)。
文摘Assembling MnO_(2)nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity,yet its development is limited by the deficiencies in preparation and property modulation of the MnO_(2)nanowires.In this work,we developed a facile method using C_(2)H_5OH and CH_(3)COOK as reductive and vital control reagents to react with KMnO_(4)by hydrothermal reaction at 140℃for 12 h,to prepare the ultralongα-MnO_(2)nanowires up to tens of micrometers with high purity and aspect ratio.Such strategy not only had the advantages of being mild,easily controlled and environmental pollution-free,but also endowedα-MnO_(2)nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds(k_(obs)=0.0738~0.1695 min^(-1))in a continuous flow reaction.The reactive oxygen species(i.e.,~·OH)from Fenton-like reaction were enriched within thisα-MnO_(2)nanowire membrane via nanoconfinement effect,which further enhanced the mass transportation of~·OH available for phenolic contaminants.MnO_(2)nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances.
基金supported by the National Natural Science Foundation of China (Nos. 50876058 and 20876042)Program for New Century Excellent Talents in University(NCET-10-883)Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning
文摘Oleylamine (G18) and octanol (G8) were grafted onto the surfaces of the multi-walled carbon nanotubes (CNTs). The grafted CNTs were dispersed into palmitic acid (PA) and paraffin wax (PW) to prepare phase change composites. The heat storage/retrieval experiments showed that the composites kept stable after repeating melting and solidification for 80 times. The structure of the G18-CNT/PA and G8-CNT/PA was homogenous compared with the pristine CNT (P-CNT)/PA. The latent heat capacity (Ls) of solid liquid phase change of G18-CNT/PW was higher than that of PW while those of the G8-CNTI/PW and P-CNT/PW were lower than that of PW. Compared with PA, all PA based composites with both P-CNTs and grafted CNTs decreased Ls evidently. The Ls values of GI8-CNT composites in both matrices were higher than that of the counterparts of G8-CNT. The thermal conductivities of all the PA based composites in the study were higher than that of PA, as well as those of all the PW based composites. However, the thermal conductivities of the GI8-CNT composites in both matrixes were lower than those of the G8-CNT composites in both matrixes at all measured temperatures.
基金supported by Program for New Century Excellent Talents in University (NECT-10-883)the National Natural Science Foundation of China (50876058)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning
文摘Aluminum nitride nanoparticles (AINs) have been found to be a good additive for enhancing the thermal conductivity of traditional heat exchange fluids. At a volume fraction of 0.1, the thermal conductivity enhancement ratios are 38.71% and 40.2%, respectively, for ethylene glycol and propylene glycol as the base fluids. Temperature does not have much influence on the enhanced thermal conductivity ratios of the nanofluids, though a volume fraction of 5.0% appears to signify a critical concentration for rheology: for 〈5.0vo1% for Newtonian behavior, and for 〉5.0vo1% for obvious shear-shinning behavior, for both ethylene glycol and propylene glycol.
基金This study was supported by the National Natural Science Foundation of China (Grant No. 41001331), The Programme of Introducing Talents of Discipline to University (111 Project) and the Natural Science Foundation of Shanghai (Grant No. 15ZR1428700). The authors thank Professor Lu Ming and Zhou Limin of East China Normal University for their help with geochemical analysis. Thanks to Cashion for the language modification.
文摘This study presents the results obtained from magnetic susceptibility and heavy metal (Cu, Zn, Pb, and Cr) concentration measurements of soil profiles collected from arable land and urban parks in Baoshan District, an industrial district of Shanghai, China. The study focuses on the investigation of vertical variations in magnetic susceptibilities and heavy metal concentrations and on correlations between magnetic susceptibilities and heavy metal concentrations in soil profiles. The results demon- strate that magnetic enhancement in the surface layer of the soil profile is associated with increased heavy metal pollution. The enrichment factors (EF) and the Tomlinson Pollution Load Index (PLI-EF) are calculated for estimat- ing the level of heavy metal pollution of soil profiles in the study. The significant positive correlations between heavy metal contents, enrichment factors (EF), Tomlinson pollution load index (PLI-CF), modified Tomlinson pollution load index (PLI-EF), and magnetic susceptibility (X) indicate that much of the heavy metal contamination in the study area is linked to combustion derived particulate emissions. The results confirm that the combined magnetic measurement and heavy metal concentration analysis could provide useful information for soil monitoring in urban environments. However, the use of magnetic technique to locate the heavy metal pollution boundary in the soil profile of this studied area should be confirmed by further geochemical analysis.
基金supported by the 2013 Research Fund of Ulsan National Institute of Science and Technology through a Future Challenge Project
文摘Anaerobic digestion (AD) is gaining increasing attention due to the ability to covert organic pollutants into energy-rich biogas and, accordingly, growing interest is paid to the microbial ecology of AD systems. Despite extensive efforts, AD microbial ecology is still limitedly understood, especially due to the lack of quantitative information on the structures and dynamics of AD microbial communities. Such knowledge gap is particularly pronounced in sewage sludge AD processes although treating sewage sludge is among the major practical applications of AD. Therefore, we examined the microbial communities in three full-scale sewage sludge digesters using qualitative and quantitative molecular techniques in combination: denaturing gradient gel electrophoresis (DGGE) and real-time polymerase chain reaction (PCR). Eight out of eleven bacterial sequences retrieved from the DGGE analysis were not affiliated to any known species while all eleven archaeal sequences were assigned to known methanogen species. Quantitative real-time PCR analysis revealed that, based on the 16S rRNA gene abundance, the hydrogenotrophic order Methanomicrobiales is the most dominant methanogen group (〉 94% of the total methanogen population) in all digesters. This corresponds well to the prevailing occurrence of the DGGE bands related to Methanolinea and Methanospirillum, both belonging to the order Methanomicrobiales, in all sludge samples. It is therefore suggested that hydrogenotrophic methanogens, especially Methanomicrobiales strains, are likely the major players responsible for biogas production in the digesters studied. Our observation is contrary to the conventional understanding that aceticlastic methanogens generally dominate methanogen communities in stable AD environments, suggesting the need for further studies on the dominance relationship in various AD systems.
文摘Synthesis of TiO2 nanoparticles by the oxidation of titanium tetrachloride (TiCI4) in high-strength propane/air turbulent flame is investigated tentatively for mass production of TiO2 nanoparticles. Effects of reactor heat flux varying from 247 to 627 kJ/m^2 s, initial TiO2 number density from 2 × 10^20 to 1 × 10^21 m^ 3, and apparent residence time of TiO2 nanoparticles in reactor from 0.06 to 0.9 s, on particle morphology, phase composition, UV absorption and photoluminescence (PL) spectra are studied. The TiO2 nanoparticles synthesized, with mean size of 30-80 nm and futile mass fraction from 0.155 up to 0.575, exhibited a strong PL signal at the wavelength of 370-450 nm, with a wide peak signal at 400-420 nm, reflecting significant oxygen vacancies on the surface of the TiO2 nanoparticles.
基金supported by a grant (12-TI-C04) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government
文摘Of growing amount of food waste, the integrated food waste and waste water treatment was regarded as one of the efficient modeling method. However, the load of food waste to the conventional waste treatment process might lead to the high concentration of total nitrogen(T-N) impact on the effluent water quality. The objective of this study is to establish two machine learning models-artificial neural networks(ANNs) and support vector machines(SVMs), in order to predict 1-day interval T-N concentration of effluent from a wastewater treatment plant in Ulsan, Korea. Daily water quality data and meteorological data were used and the performance of both models was evaluated in terms of the coefficient of determination(R^2), Nash-Sutcliff efficiency(NSE), relative efficiency criteria(d rel). Additionally, Latin-Hypercube one-factor-at-a-time(LH-OAT) and a pattern search algorithm were applied to sensitivity analysis and model parameter optimization, respectively. Results showed that both models could be effectively applied to the 1-day interval prediction of T-N concentration of effluent. SVM model showed a higher prediction accuracy in the training stage and similar result in the validation stage.However, the sensitivity analysis demonstrated that the ANN model was a superior model for 1-day interval T-N concentration prediction in terms of the cause-and-effect relationship between T-N concentration and modeling input values to integrated food waste and waste water treatment. This study suggested the efficient and robust nonlinear time-series modeling method for an early prediction of the water quality of integrated food waste and waste water treatment process.
基金The authors are grateful for a research grant from Shanghai Education Committee (07ZZ180)a fund from the Second Shanghai Key Discipline Construction Plan of Shanghai Municipal EducationCommission (P1701)
文摘Photodegradation of benzene at ppb levels by mixed-phase TiO2 nanoparticles, synthesized by the oxidation of TiCl4 in propane/air turbulent flame chemical vapor deposition (CVD) process, is investigated experimentally by using a tubular photoreactor with thin TiO2 films coated on the reactor wall by sedimentation. Effects of inlet benzene concentration from 10 to 300μg/m3, rutile mass fraction from about 20 to 50% and photoluminescence (PL) intensity of TiO2 nanoparticles on degradation degree are examined under the conditions of 70% relative humidity, 38 μg/cm2 catalyst loading, 24mW/cm2 UV irradiation of 254 nm and 5.7 s residence time in the reactor. Based on experimental results, separation of photoinduced electron (e-) and hole (h+) pairs by rutile phase is discussed as photo-induced electron (e-) in anatase phase will migrate to rutile surface due to that the potential of conductive band of rutile is lower than that of anatase, leading to more holes ready on anatase surface for oxidation reactions.
基金The authors gratefully acknowledge the financial support from Tianjin Enterprise Science and Technology Commissioner Project(No.19JCTPJC46900)Tianjin Municipal Education Commission Research Plan Projects(Nos.2018KJ161 and TJPU2k20170112)+5 种基金Tianjin Chengjian University research fund(No.180501412)the National Key Research and Development Program of China(No.2018YFC1903203)the Fundamental Research Funds for the Central Universities,China(2020CDJQY-A017)Chongqing Technological Innovation and Application Development Project(No.cstc2019jscx-tjsbX0002)The work described in this paper was also partially supported by a grant from the Research Grants Council of the Hong Kong Special Administration Region,China(No.C7051-17G)Tao Lei from Metrohm China is also gratefully acknowledged for providing useful information about Metrohm Autolab potensiostat.The financial support of the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Actions IF Grant agreement(No.748683)is gratefully acknowledged.
文摘Reverse electrodialysis(RED)is an emerging membrane-based technology for the production of renewable energy from mixing waters with different salinities.Herein,the impact of the stack configuration on the Ohmic and non-Ohmic resistances as well as the performance of RED were systematically studied by using in situ electrochemical impedance spectroscopy(EIS).Three different parameters(membrane type,number of cell pairs and spacer design)were controlled.The Ohmic and non-Ohmic resistances were evaluated for RED stacks equipped with two types of commercial membranes(Type I and Type II)supplied by Fujifilm Manufacturing Europe B.V:Type I Fuji membranes displayed higher Ohmic and non-Ohmic resistances than Type II membranes,which was mainly attributed to the difference in fixed charge density.The output power of the stack was observed to decrease with the increasing number of cell pairs mainly due to the increase in ionic shortcut currents.With the reduction in spacer thickness from 750 to 200μm,the permselectivity of membranes in the stack decreased from 0.86 to 0.79 whereas the energy efificiency losses increased from 31%to 49%.Overall,the output of the present study provides a basis for understanding the impact of stack design on internal losses during the scaling-up of RED.
文摘Wind power systems have gained much attention due to the relatively high reliability, maturity in technology and cost competitiveness compared to other renewable alternatives. Advances have been made to increase the power efficiency of the wind turbines while less attention has been focused on structural integrity assessment of the structural systems. Vibration-based damage detection has widely been researched to identify damages on a structure based on change in d^mmic characteristics. Widely spread methods are natural frequency-based, mode shape-based, and curvature mode shape-based methods. The natural frequency-based methods are convenient but vulnerable to environmental temperature variation which degrades damage detection capability; mode shapes are less influenced by temperature variation and able to locate damage but requires extensive sensor instrumentation which is costly and vulnerable to signal noises. This study proposes novelty of damage factor based on sensor fusion to exclude effect of temperature variation. The combined use of an accelerometer and an inclinometer was considered and damage factor was defined as a change in relationship between those two measurements. The advantages of the proposed method are: 1) requirement of small number of sensor, 2) robusmess to change in temperature and signal noise and 3) ability to roughly locate damage. Validation of the proposed method is carried out through numerical simulation on a simplified 5 MW wind turbine model.
基金an innovation research grant(13YZ130)a Leading Academic Discipline Project(J51803)from the Shanghai Education Committeea Cultivate Discipline Fund of the Shanghai Second Polytechnic University(XXKPY1303)
文摘Mass transfer between a bubble and the dense phase in gas fluidized beds of Group A and Group B particles was proposed based on previous experimental results and literature data. The mass transfer coefficient between bubbles and the dense phase was determined by kbe = 0.21 db. A theoretical analysis of the mass transfer coefficient between a bubble and the dense phase using diffusion equations showed that the mass transfer coefficient between a bubble and the dense phase is kbe α εmf√ub/db in both three- and two-dimensional fiuidized beds. An effective diffusion coefficient in gas fluidized beds was introduced and correlated with bubble size as De = 13.3db2.7 for Group A and Group B particles. The mass transfer coefficient kbe can then be expressed as kbe = 0.492εmf√ubdb1.7 for bubbles in a three-dimensional bed and kbe = 0.576εm√ubdb1.7 for bubbles in a two-dimensional bed.
基金the Innovation Research Grant (13YZ130)the Leading Academic Discipline Project(J51803) from the Shanghai Education Committeefor the research fund from Shanghai Pudong Hydrology and Water Resource Administration
文摘The capture of orthophosphates and total phosphorus from the Pudong Canal river in the Pudong District of Shanghai by TiO2 nanoparticles is studied using a rotating photoreactor and the nano-TiO2 photocatalyst Degussa P25. The effects of UV irradiation intensity in a range of 20-74 mW/cm^2, the loading of the TiO2 nanoparticles in a range of 0.05-0.1 g/L, irradiation time up to 4 h, and pH values in a range of 2-10.5 on the capture efficiency are investigated. The results show that the capture of orthophosphates and total P are significantly enhanced by UV irradiation; at a loading of 0.1 g/L and an irradiation intensity above 36 mW/cm^2, orthophosphates and total phosphorus are rapidly captured by TiO2 nanoparticles, causing an observed reduction from 0.4 mg/L down to 0.02 mg/L. pH values in a range of 2-10.5 have little effect on the capture efficiency of orthophosphates and total phosphorus.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2016R1A1A3A04005520 and 2017K2A9A1A06056874)supported by the National Science Foundation (AGS-1934392)+1 种基金The Community Earth System Model project is supported primarily by the National Science Foundation (NSF)supported by the National Center for Atmospheric Research, which is a major facility sponsored by the NSF under Cooperative Agreement (1852977)。