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气相色谱法测定水和废水中丙烯腈 总被引:2,自引:0,他引:2
本文通过采用气相色谱法,以GDX-502为固定相,FID为检测器测定水和废水中的丙烯腈,精密度和回收率高.方法简便易行,能满足行业废水和地面水的监队是水和废水中丙烯腈分析的较理想方法。 相似文献
2.
C. B. England 《Journal of the American Water Resources Association》1975,11(3):559-567
ABSTRACT: Soil moisture in two layers of a soil near Chickasha, Oklahoma, was simulated, using USDAHL-74 Model of Watershed Hydrology. Weekly values computed for both layers compared well with those observed during the 15-month period. Certain key parameters required adjustments in the model which illustrate the need for accurate input information. The experiment demonstrates that the model, which has previously given good results in continuous streamflow prediction on watersheds up to 100 square miles, can also compute soil moisture continuously at a site. This capability suggests other model uses, for example, in monitoring the disposition of applied chemicals. 相似文献
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Bevin Keen Ellen England Timothy Webb Summer Bartczak Charles Bleckmann 《补救:环境净化治理成本、技术与工艺杂志》2006,16(4):71-80
Environmental compliance requirements periodically impact the military's ability to use all installation resources. In response, environmental management strategies have been developed to ensure compliance and allow site closure. This study examines the relationship between environmental management strategies and environmental compliance at U.S. Marine Corps (USMC) installations via analysis of environmental compliance audit scores. Five environmental scores of interest from 1998 to 2004 audits—which include total compliance, total management, audit management, policy management, and training management—were subjected to statistical analysis. Results showed the USMC met environmental compliance and management standards, despite limited resources. High management strategy scores were moderately correlated with high total compliance scores. Total management scores improved over time, and noncompliance was most often associated with a lack of resources and plans. © 2006 Wiley Periodicals, Inc. 相似文献
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ABSTRACT A comprehensive mathematical watershed model containing a complete soil moisture accounting system was used to simulate the hydrologic processes measured in one of the weighing lysimeters at Coshocton, Ohio. Data from a four-year rotation were used to calibrate the parameters initially selected for the model. Data from the succeeding four years were used to evaluate the predictions. Reasonable agreement was obtained between observed and predicted percolation and evapo-transpiration values. 相似文献
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M.-C. Oliver Chang Judith C. Chow John G. Watson Philip K. Hopke Seung-Muk Yi Glenn C. England 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1494-1505
Abstract Currently, we have limited knowledge of the physical and chemical properties of emitted primary combustion aerosols and the changes in those properties caused by nucleation, condensation growth of volatile species, and particle coagulations under dilution and cooling in the ambient air. A dilution chamber was deployed to sample exhaust from a pilot-scale furnace burning various fuels at a nominal heat input rate of 160 kW/h?1 and 3% excess oxygen. The formation mechanisms of particles smaller than 420 nm in electrical mobility diameter were experimentally investigated by measurement with a Scanning Mobility Particle Sizer (SMPS) as a function of aging times, dilution air ratios, combustion exhaust temperatures, and fuel types. Particle formation in the dilution process is a complex mixture of nucleation, coagulation, and condensational growth, depending on the concentrations of available condensable species and solid or liquid particles (such as soot, ash) in combustion exhausts. The measured particle size distributions in number concentrations measured show peaks of particle number concentrations for medium sulfur bituminous coal, No. 6 fuel oil, and natural gas at 40-50 nm, 70-100 nm, and 15-25 nm, respectively. For No. 6 fuel oil and coal, the particle number concentration is constant in the range of a dilution air ratio of 50, but the number decreases as the dilution air ratio decreases to 10. However, for natural gas, the particle number concentration is higher at a dilution air ratio of 10 and decreases at dilution air ratios of 20-50. At a dilution air ratio of 10, severe particle coagulation occurs in a relatively short time. Samples taken at different combustion exhaust temperatures for these fuel types show higher particle number concentrations at 645 K than at 450 K. As the aging time of particles increases, the particles increase in size and the number concentrations decrease. The largest gradient of particle number distribution occurs within the first 10 sec after dilution but shows only minor differences between 10 and 80 sec. The lifetimes of the ultrafine particles are relatively short, with a scale on the order of a few seconds. Results from this study suggest that an aging time of 10 sec and a dilution air ratio of 20 are sufficient to obtain representative primary particle emission samples from stationary combustion sources. 相似文献
7.
Phillip R. England Fiona Beynon David J. Ayre Robert J. Whelan 《Conservation biology》2001,15(6):1645-1655
Abstract: Introductions of European honeybees have occurred globally, potentially affecting the natural pollination ecology of many plants. Introduced honeybees are now the most frequent visitors to the inflorescences of the self-compatible, bird-pollinated Australian shrub Grevillea macleayana and may therefore be expected to have altered the mating system. To examine the degree to which birds continue to play a role in determining the mating system of G. macleayana in this disturbed system, we compared outcrossing rates in open-pollinated inflorescences with inflorescences from which birds had been selectively excluded. Outcrossing rates were estimated from the microsatellite genotypes of over 100 seeds per population in three populations. Outcrossing rates ( t ) in open-pollinated seeds were surprisingly low (0.062–0.225) and did not vary significantly among the three populations. Nevertheless, outcrossing was significantly lower when birds were excluded (data pooled from all populations). Two lines of evidence suggest that there are temporal fluctuations in outcrossing rate and hence that birds usually have a major effect on the mating system of G. macleayana . First, at one site, t was substantially lower than estimates from an earlier study (0.06 in 1995 cf. 0.85 in 1990). Second, fixation indices based on seeds were high in all populations ( >0.68), whereas values for the established plants ( parental generation) were much lower in two of the three populations (0.06–0.32). Our findings suggest that honeybee activity is so high that the contribution of birds to pollination in G. macleayana is sometimes relatively trivial. 相似文献
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The relationship between CFC-11 and anthropogenic CO2 (deltaDIC(ant)) concentrations in the world ocean are evaluated based on a simple off-line tracer ventilation model. Since the different solubility characteristics of CFC-11 and deltaDIC(ant) cause major differences in their oceanic uptake features, indicating different uptake pathways, a care should be taken while assessing deltaDIC(ant) in the oceans relying on CFC-11 concentrations. Evidence will be provided that CFC-11 storage occurs mainly in colder, high latitude regions, whereas the warmer, low latitude regions of the world ocean play an important role in both storing and absorbing anthropogenic CO2. This can be caused by an increased CO2 uptake or by a reduced CO2 release to the atmosphere at lower latitudes, both as a result of increasing atmospheric CO2 concentrations. 相似文献
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The pedal retractor muscle of Nassarius coronatus, unlike most mollusc muscles, contains high activities of both octopine dehydrogenase (159 IU g-1 wet wt muscle) and D-lactate dehydrogenase (40 IU g-1 wet wt muscle). Pedal retractor muscles show accumulation of octopine (increase of 4.7 mol g-1 wet wt muscle), and a fall in arginine phosphate concentration (decrease of 4.1 mol g-1 wet wt musscle) after exercise. During recovery from exercise, octopine returns to resting levels after about 120 min, D-lactate accumulates (5.1 mol g-1 wet wt muscle), and arginine phosphate returns to resting levels within 30 min. D-lactate (2.0 mol g-1 wet wt muscle) accumulates during long-term exposure to air. The results show that octopine dehydrogenase and D-lactate dehydrogenase can function to catalyze the terminal step of glycolysis during muscle anoxia associated with these different physiological states. 相似文献
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Hazardous air pollutant emissions from gas-fired combustion sources: emissions and the effects of design and fuel type 总被引:1,自引:0,他引:1
Air emissions from gas-fired combustion devices such as boilers, process heaters, gas turbines and stationary reciprocating engines contain hazardous air pollutants (HAPs) subjected to consideration under the federal clean air act (CAA). This work presents a recently completed major research project to develop an understanding of HAP emissions from gas-fired boilers and process heaters and new HAP emission factors based on field emission tests of gas-fired external combustion devices used in the petroleum industry. The effect of combustion system design and operating parameters on HAP emissions determined by both field and research tests are discussed. Data from field tests of gas-fired petroleum industry boilers and heaters generally show very low emission levels of organic HAPs. A comparison of the emission data for boilers and process heaters, including units with and without various forms of NOx emission controls, showed no significant difference in organic HAP emission characteristics due to process or burner design. This conclusion is also supported by the results of research tests with different burner designs. Based on field tests of units fired with natural gas and various petroleum industry process gases and research tests in which gas composition was intentionally varied, organic HAP emissions were not determined to be significantly affected by the gas composition. Research data indicate that elevated organic HAP emission levels are found only under extreme operating conditions (starved air or high excess air combustion) associated with poor combustion. 相似文献