The characteristics and sustainable management of water resources on a basin scale require that they should be managed using a holistic *** this study,a holistic methodology called the holistic approach in a basin sca...
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The characteristics and sustainable management of water resources on a basin scale require that they should be managed using a holistic *** this study,a holistic methodology called the holistic approach in a basin scale(HABS)is proposed to determine the ecological water requirements of a whole *** are three principles in ***,ecological water requirements in a basin scale indicate not only the coupling of hydrological and ecological systems,but also the exchange of matter and energy between each ecological type through all kinds of physical geography ***,ecological water requirements can be divided into different types according to their functions,and water requirements of different types are ***,ecological water requirements are related to a multiple system including water quality,water quantity,and time and space,which interact with each *** holistic approach in a basin scale was then used in the Yellow River Basin and it suggested that 265.0x108 m3 of water,45%of the total surface water resources,should be allocated to ecological systems,such as rivers,lakes,wetlands and cities,to sustain its function and *** ecological water requirements of inside river systems and outside river systems were respectively 261.0×10^(8) and 3.65×10^(8)m^(3).
Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain ...
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Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters （PMzs） from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon （EC） and organic carbon （OC） was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum （GC-MS）. Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. 13-Sitostrol also made up relatively a large fraction of PMz5 compared with the other sterols （0.18%-0.63% of the total fine particle mass）. Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index （CPI） of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.
Agricultural activity is one of the most important sources of aerosol *** understand the mass distribu-tion and sources of aerosol particles and their inorganic water-soluble ions in a suburb farmland of Beijing,parti...
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Agricultural activity is one of the most important sources of aerosol *** understand the mass distribu-tion and sources of aerosol particles and their inorganic water-soluble ions in a suburb farmland of Beijing,particle samples were collected using a microorifice uniform deposit impactor(MOUDI)in the summer of 2004 in a suburb vege-table *** distribution of the particles and their inor-ganic water-soluble ions in the diameter range of 0.18-18 mm were *** dominant fine particle ions were SO_(4)^(2−),NO^(3−),and NH_(4)^(+).The association of day-to-day variation of the concentration of these ions with temperature,humidity,and solar radiation suggested that they are formed by the reac-tion of NH_(3) released from the vegetable field with the acid species produced from photochemical *** particle K+is likely from vegetation emission and biomass *** particles like Ca^(2+),Mg^(2+),NO_(3)^(−),and SO_(4)^(2−)are sug-gested to come from the mechanical process by which the soil particle entered the atmosphere,and from the reaction of the acid species at the surface of the soil *** results show that fertilizer and soil are important factors determining the aerosol particle over agricultural fields,and vegetable fields in suburban Beijing contribute significantly to the aerosol particle.
fouling online in an anaerobic membrane bioreac-tor(AMBR).Short-term running experiments were carried out under different operating conditions to explore feasible ultrasonic *** experimental results indicated that whe...
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fouling online in an anaerobic membrane bioreac-tor(AMBR).Short-term running experiments were carried out under different operating conditions to explore feasible ultrasonic *** experimental results indicated that when the crossflow velocity was more than 1.0 m/s,mem-brane fouling could be controlled effectively only by hydro-dynamic methods without *** ultrasound was applied,an ultrasonic power range of 60-150 W was suitable for the membrane fouling control in the experimental *** experimental results showed that the membrane fouling was controlled so well that membrane filtration resistance(ΣR)could stay at 5×10^(11)m^(−1) for more than a week with the crossflow velocity of 0.75 m/s,which equaled the effect of crossflow velocity of more than 1.0 m/s without ultrasound.
Based on Remote Sensing(RS),Geographical Information Systems(GIS),and the Spatial Principal Compo-nent Analysis(SPCA)method,the integrated assessment and changes in the ecological environment of Daning River Watershed...
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Based on Remote Sensing(RS),Geographical Information Systems(GIS),and the Spatial Principal Compo-nent Analysis(SPCA)method,the integrated assessment and changes in the ecological environment of Daning River Watershed are studied in this *** watershed is located in the Three Gorge Area in *** result of the integrated assessment showed that level 9 had the biggest proportion in the year 1990,which was about 40%.In the year 2000,however,there were no levels with a proportion significantly bigger than the *** comparing the assessment results in 1990 and 2000,it is discovered that the ecological environ-ment in Daning River Watershed in 1990 was better than that in 2000.
The mechanism and kinetics of the production of hydroxymethyl hydroperoxide (HMHP) in ethene/ozone/water gas-phase system were investigated at room temperature (298±2 K) and atmospheric pressure (1×105 Pa). ...
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The mechanism and kinetics of the production of hydroxymethyl hydroperoxide (HMHP) in ethene/ozone/water gas-phase system were investigated at room temperature (298±2 K) and atmospheric pressure (1×105 Pa). The reactants were monitored in situ by long path FTIR spectroscopy. Peroxides were measured by an HPLC post-column fluorescence technique after sampling with a cold trap. The rate constants (k 3) of reaction CH2O2+H2O→HMHP (R3) determined by fitting model calculations to experimental data range from (1.6?6.0)×10?17 cm3·molecule?1·s?1. Moreover, a theoretical study of reaction (R3) was performed using density functional theory at QCISD(T)/6-311+(2d,2p)//B3LYP/6-311+G(2d,2p) level of theory. Based on the calculation of the reaction potential energy surface and intrinsic reaction coordinates, the classic transitional state theory (TST) derived k 3 (k TST), canonical variational transition state theory (CVT) derived k 3 (k CVT), and the corrected k CVT with small-curvature tunneling (k CVT/SCT) were calculated using Polyrate Version 8.02 program to be 2.47×10?17, 2.47×10?17 and 5.22×10?17 cm3·molecule?·s?1, respectively, generally in agreement with those fitted by the model.
The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium in a nitrogen-limited(C/N ratio is 56/8.8 mmol/L)*** sets of shaking flask experiments wer...
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The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium in a nitrogen-limited(C/N ratio is 56/8.8 mmol/L)*** sets of shaking flask experiments were *** results showed that 2 g/L glucose feeding on the first day of the culture(24 h after the inoculation)stimulated both fungal biomass growth and enzyme *** manganese peroxidase(MnP)activ-ity was 2.5 times greater than that produced in cultures with-out glucose ***,the glucose feeding mode in fed-batch culture was also *** to cul-tures with glucose feeding every 48 h,cultures with glucose feeding of 1.5 g/L(final concentration)every 24 h produced more *** peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture,respectively,and the enzyme was kept stable for 4 days with an activity of over 200 U/L.
Fourteen SAE standards related to accommodation and occupant＇ packaging for vehicle interior are studied. The influencing factors, key reference accommodation points and major design dimensions and their relationship...
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Fourteen SAE standards related to accommodation and occupant＇ packaging for vehicle interior are studied. The influencing factors, key reference accommodation points and major design dimensions and their relationships of occupant packaging and ergonomics during the vehicle interior layout design and development are analyzed. Prototypes are presented to verify the results and how to achieve the packaging is shown. Auto- mobile designers can achieve significant practical guidance for human safety, efficiency accommodation and occupant packaging of all passengers during the vehicle design process.
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