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951.
长三角区域一体化发展趋势下的资源环境压力分析 总被引:2,自引:0,他引:2
长江三角洲区域是我国社会经济发展的发达地区。近年来,在其社会经济区域一体化发展趋势日益显著的同时,区域环境问题也越来越呈现“一荣俱荣、一损俱损”的一体化特征。同时,长三角作为1个资源能源高需求并主要依赖区外供给的地区,其资源能源利用与生态环境息息相关。在研究分析区域发展趋势与环境问题现状的基础上,重点从社会经济发展以及土地资源、水资源、能源等方面,探讨长三角区域环境面临的压力,并提出解决长三角区域环境问题的一些基本对策措施,为决策者提供参考。 相似文献
952.
K. C. Chun R. W. Chang G. P. Williams Y. S. Chang D. Tomasko K. LaGory J. Ditmars H. D. Chun B. -K. Lee 《Environmental Engineering and Policy》1999,2(3):131-143
A framework for evaluating alternative management strategies for the Nakdong River Basin in the Republic of Korea (South Korea) was developed and applied jointly by Argonne National Laboratory in Argonne, Illinois, USA, and the Research Institute of Industrial Science and Technology in Pohang, South Korea. Water from this basin, the second largest in South Korea, supports a total population of more than 13 million people. Rapid industrial expansion, urbanization, and population growth have dramatically increased the demand for water and have severely degraded water quality, particularly near large industrial complexes and in the lower portion of the basin. Management strategies for the entire basin through to the year {dy2011} were evaluated with a computer model for basin-wide predictions of water flow and quality (HSPF). This continuous-event model was developed and calibrated using site-specific data for the basin over a two-year period (1994-1995) that included periods of both high (monsoonal) and low (drought) flows. Water quality impacts for different wastewater treatment strategies were assessed in terms of biochemical oxygen demand (BOD), nitrogen (N) and phosphorous (P) levels. The results of the study indicate that BOD levels in the main stem of the Nakdong River below the Kumhogang (a major tributary with low flow and heavy pollution loads) cannot be significantly improved by reducing direct BOD loads from point sources along the river. To reduce main stem BOD levels, the nutrient loading to the river must be reduced. In order to reduce these loads, additional advanced treatment methods (i.e., tertiary treatment) must be incorporated in the treatment facilities to remove N and P. The discharge inventory data further suggest that a large portion of N and P loads are derived from non-point agricultural practices. Reduction of these loads is difficult to accomplish and may require extensive modifications in agricultural and land-use practices. The modeling frame-work developed provides a means to evaluate these and other basin management strategies. 相似文献
953.
Persistence and fate of polychlorinated biphenyls (PCBs) in sewage sludge-amended agricultural soils 总被引:1,自引:0,他引:1
Alcock RE Bacon J Bardget RD Beck AJ Haygarth PM Lee RG Parker CA Jones KC 《Environmental pollution (Barking, Essex : 1987)》1996,93(1):83-92
Four metal enriched sewage sludges containing different concentrations of polychlorinated biphenyls (PCBs) were applied to two field soils in the UK in 1968. Samples of the sludges, sludge-amended soils and soils from untreated control plots were stored and analysed retrospectively. Sludge concentrations ranged from 1 to 7 mg SigmaPCB kg(-1). The pattern of PCBs was similar in three of the four sludges, with congeners 14, 18, 28 and 52 present at the highest concentrations. The fourth sludge contained higher amounts of congeners 149, 153, 138 and 180. SigmaPCB concentrations in control plot soil have declined over the last 20 years, indicating a reduction in atmospheric deposition inputs of PCBs to the soil. SigmaPCB concentrations also declined on the sludge-amended plots, reaching control plot concentrations (30-60 microg SigmaPCB kg(-1)) in the late-1980s. Half-lives ranged from < 1 to 8.5 years for congeners 18, 28 and SigmaPCB. Biodegradation and/or the formation of reversibly sorbed soil PCB residues could not account for the losses observed. Volatilisation is implicated as the most important loss process on both the control and sludge-amended plots. Using the fugacity approach, congener concentrations in soils at Luddington were predicted still to have not reached equilibrium with the air. Further losses to the atmosphere are likely. 相似文献
954.
Patrick R. Zimmerman Maribeth Price Changhui Peng William J. Capehart Karen Updegraff Patrick Kozak Lee Vierling Elaine Baker Fred Kopp Genet Duke Chandan Das 《Mitigation and Adaptation Strategies for Global Change》2005,10(2):307-331
The C-Lock system was developed to address the need for an improved method of quantifying and certifying project-level carbon emission reduction credits (CERC). It was designed to enable individual landowners to efficiently quantify, certify, pool, market and trade CERCs generated by agricultural management practices. We provide a general overview of the C-Lock system as it has been implemented for the USA State of South Dakota. C-Lock is comprised of four linked components: a web interface, a client database, a Geographic Information System (GIS) database of soil, climate and generalized land use history parameters, and the CENTURY soil carbon model. The user-friendly interface elicits generalized land-use and crop history information from the client from 1900 through 1989, then explicit annual information from 1990 onward. A climate-zone level landuse and crop management database is used to fill in gaps in the client-provided data. These data are used to drive the CENTURY model, which estimates annual changes in soil carbon stocks. Monte Carlo simulation is used to estimate uncertainty bounds, and these are applied to the CENTURY outputs in order to provide probabilistic estimates of accrued CERCs in a manner that is transparent and verifiable. In a demonstration application, CERCs are estimated for three different land-use scenarios on a representative field in eastern South Dakota: reduced tillage or conservation (no-till) management of a corn (maize)/wheat/soybean rotation, and enrollment in the Conservation Reserve Program, which entails establishing permanent grass cover. The credits are based on a business-asusual scenario of conventional tillage. 相似文献
955.
Wayne H. Persutte B.S. R.D.M.S. Thaddeus W. Kurczynski K. Chaudhuri Roger R. Lenke Lee Woldenberg Ray A. Brinker 《黑龙江环境通报》1990,10(10):631-642
A case of fetal autosomal dominant microcephaly was prenatally diagnosed with ultrasonography in a woman with previously undiagnosed microcephaly. At the time of initial ultrasonographic assessment, the mother was identified to have a markedly small cranium, consistent with maternal microcephaly. The ultrasonographic examination showed the fetal head size to be four standard deviations below the mean for gestational age. Gesta-tional dating from the other biometric parameters and from the last menstrual period was consistent with 31 weeks' gestation. Neurosonographic evaluation of the fetus revealed no obvious structural abnormalities. Serial ultrasonographic examinations at 35 and 38 weeks' gestation showed no changes in the fetal head size. A 2·64 kg male fetus was delivered at term. Neonatal assessment showed the fetal head circumference to be less than the second percentile for gestational age. Neurologic assessment of the neonate with magnetic resonance imaging showed abnormal development of the brain, with small cerebellar and cerebral hemispheres, and pachygyria. These images are compared with the magnetic resonance images of the mother. Our findings of maternal and fetal microcephaly are consistent with autosomal dominant microcephaly. To our knowledge, this is the first report of the prenatal diagnosis of autosomal dominant microcephaly. 相似文献
956.
Susan J. Gross MD Owen P. Phillips Lee P. Shulman N. Lawrette Bright Jeffrey S. Dungan Joe Leigh Simpson Sherman Elias 《黑龙江环境通报》1994,14(7):609-613
An association between various abnormal mid-trimester maternal serum analyte values and adverse perinatal outcome has been reported. From an original sample of 14 857 women, we observed five women who were ‘screen-positive’ for both neural tube defects [maternal serum alpha-fetoprotein (MSAFP) ≥2·5 multiples of the median] and Down syndrome [risk ≥1/274 using MSAFP, maternal serum unconjugated oestriol (MSuE3), maternal serum human chorionic gonadotropin (MShCG), and maternal age]. The four patients who elected to undergo amniocentesis all demonstrated both normal karyotype and normal amniotic fluid AFP levels. All five cases were associated with intrauterine growth retardation (IUGR) and abnormal pregnancy outcomes. Two cases exhibiting severe IUGR on ultrasound examination were terminated at 19·1 and 21·2 weeks, respectively; the former also exhibited fetal calcifications and positive maternal serology for toxoplasmosis. In another case, fetal demise occurred at 36 weeks' gestation in a patient who had been treated for syphilis in the second trimester. Neither infection was confirmed in fetal tissue studies. Though resulting in live births, the remaining two cases required operative deliveries; emergency Caesarean sections for fetal distress were performed at 38 and 32 weeks, respectively, the latter case being associated with severe pre-eclampsia. We conclude that elevated mid-trimester MSAFP levels concurrent with maternal serum analyte values associated with increased risk for fetal Down syndrome may presage a poor perinatal outcome, particularly IUGR and possibly congenital infection. 相似文献
957.
Speciation of copper in the channels of MCM-41 during reduction of NO with CO at 473-773 K was studied by in situ extended X-ray absorption fine structural (EXAFS) and X-ray absorption near edge structural (XANES) spectroscopies in the present work. The component fitted (in situ) XANES spectra of the catalyst showed that about 72% of metallic copper (Cu(0)) in MCM-41 was oxidized to higher oxidation state coppers (Cu(II) (46%) and Cu(I) (26%)) during the NO reduction process (at 473 K). By EXAFS, we also found that in the NO reduction process, oxygen was inserted into the metallic copper matrix and led to a formation of the copper oxide species with a Cu-O bond distance of 1.93 A which was greater than that of the model compound Cu(2)O (typically 1.86 A). At 573-673 K, mainly Cu(II) was found in the channels of MCM-41. Nevertheless, at a higher temperature (e.g., 773 K), about 61% Cu(I), 31% Cu(II), and 8% Cu(O) with averaged Cu-Cu and Cu-O bond distances of 3.04 and 1.88 A, respectively were observed, that might account for the high selectivity-to-decomposition (S/D) ratios for yields of N(2) and CO(2) in the catalytic reduction of NO with CO. 相似文献
958.
Lee JH Hossner LR Attrep M Kung KS 《Environmental pollution (Barking, Essex : 1987)》2002,120(2):173-182
Plutonium uptake by Brassica juncea (Indian mustard) and Helianthus annuus (sunflower) from soils with varying chemical composition and contaminated with Pu complexes (Pu-nitrate [239Pu(NO3)4], Pu-citrate [239Pu(C6H5O7)], and Pu-diethylenetriaminepentaacetic acid (Pu-DTPA [239Pu-C14H23O10N3]) was investigated. Sequential extraction of soils incubated with applied Pu was used to determine the distribution of Pu in the various soil fractions. The initial Pu activity levels in soils were 44.40-231.25 Bq g(-1) as Pu-nitrate Pu-citrate, or Pu-DTPA. A difference in Pu uptake between treatments of Pu-nitrate and Pu-citrate without chelating agent was observed only with Indian mustard in acidic Crowley soil. The uptake of Pu by plants was increased with increasing DTPA rates, however, the Pu concentration of plants was not proportionally increased with increasing application rate of Pu to soil. Plutonium uptake from Pu-DTPA was significantly higher from the acid Crowley soil than from the calcareous Weswood soil. The uptake of Pu from the soils was higher in Indian mustard than in sunflower. Sequential extraction of Pu showed that the ion-exchangeable Pu fraction in soils was dramatically increased with DTPA treatment and decreased with time of incubation. Extractability of Pu in all fractions was not different when Pu-nitrate and Pu-citrate were applied to the same soil. More Pu was associated with the residual Pu fraction without DTPA application. Consistent trends with time of incubation for other fractions were not apparent. The ion-exchangeable fraction, assumed as plant-available Pu, was significantly higher in acid soil compared with calcareous soil with or without DTPA treatment. When the calcareous soil was treated with DTPA, the ion-exchangeable Pu was comparatively less influenced. This fraction in the soil was more affected with time of incubation. The lowest extractable Pu was from a pH 6.55 Crockett soil that contained the highest clay compared to the other two soils. Extractable soil Pu was largely affected by soil pH and the amounts of clay, salt, metal oxide, and carbonate. 相似文献
959.
To investigate the regional cycle of aerosols and their ionic constituents, three field intensive campaigns were conducted during fall and winter of 1997 and spring of 1998. The concentrations of most ionic species were found to decrease significantly across fall, winter, and spring such that the sum for all cation (and anion) species of each season is computed as: 193 > 96 > 73.7 nequiv m(-3) (and 240 > 104 > 51.5 nequiv m(-3)). To examine the fundamental characteristics of aerosol compositions in the study area, we conducted correlation analysis in various manners. The results indicated that the concentrations of major ionic species were strongly affected by some meteorological parameters including wind speed. It was also seen that relative strengths of correlations between important parameters (e.g., between wind speed and most of major inorganic species) maintain close relationships with the factors associated with the air mass origin. In addition, the results of factor analysis indicated the existence of at least three major sources in the study area which include: sea-salt aerosol, secondary aerosol, and organic aerosol component. The springtime occurrence of unexpectedly low concentrations of most ionic constituents is found to sensitively reflect the influence of the inflow of southeasterly winds that prevailed during spring, while it is not common for that season of the year. Because most of those changes are closely tied with the variabilities in the regional circulation patterns for each measurement period, assessment of the ionic composition in concert with the temporal variations of meteorological conditions provided valuable insights into the source signals of different air masses that passed by the study area. 相似文献
960.
In this study, we examined the influence of the long-range transport of dust particles and air pollutants on the photochemistry of OH and NO3 on Jeju Island, Korea (33.17 degrees N, 126.10 degrees E) during the Asian-dust-storm (ADS) period of April 2001. Three ADS events were observed during the periods of April 10-12, 13-14, and 25-26. Average concentration levels of daytime OH and nighttime NO3 on Jeju Island during the ADS period were estimated to be about 1x10(6) and 2x10(8) moleculescm(-3) ( approximately 9 pptv), respectively. OH levels during the ADS period were lower than those during the non-Asian-dust-storm (NADS) period by a factor of 1.5. This was likely to result from higher CO levels and the significant loading of dust particles, reducing the photolysis frequencies of ozone. Decreases in NO3 levels during the ADS period was likely to be determined mainly by the enhancement of the N2O5 heterogeneous reaction on dust aerosol surfaces. Averaged over 24 h, the reaction between HO2 and NO was the most important source of OH during the study period, followed by ozone photolysis, which contributed more than 95% of the total source. The reactions with CO, NO2, and non-methane hydrocarbons (NMHCs) during the study period were major sinks for OH. The reaction of N2O5 on aerosol surfaces was a more important sink for nighttime NO3 during the ADS due to the significant loading of dust particles. The reaction of NO3 with NMHCs and the gas-phase reaction of N2O5 with water vapor were both significant loss mechanisms during the study period, especially during the NADS. However, dry deposition of these oxidized nitrogen species and a heterogeneous reaction of NO3 were of no importance. 相似文献