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21.
IntroductionFertilizationisessentialforagriculturalproduction ,butunreasonablyapplyingfertilizerscouldresultinseriesofproblemssuchascropqualitydecline,fertilizeruseefficiencydecrease,residualfertilizerspollution groundwaterandriversandnitrogencontented … 相似文献
22.
Sathaye J.A. Makundi W.R. Andrasko K. Boer R. Ravindranath N.H. Sudha P. Rao S. Lasco R. Pulhin F. Masera O. Ceron A. Ordonez J. Deying X. Zhang X. Zuomin S. 《Mitigation and Adaptation Strategies for Global Change》2001,6(3-4):185-211
This paper summarizes studies of carbon (C) mitigation potential and costs of about 40 forestry options in seven developing countries. Each study uses the same methodological approach – Comprehensive Mitigation Assessment Process (COMAP) – to estimate the above parameters between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios. Coupled with data on a per ha basis on C sequestration or avoidance, and costs and benefits, it allows the estimation of monetary benefit per Mg C, and the total costs and carbon potential. The results show that about half (3.0 Pg C) the cumulative mitigation potential of 6.2 Petagram (Pg) C between 2000 and 2030 in the seven countries (about 200× 106 Mg C yr-1) could be achieved at a negative cost and the remainder at costs ranging up to $100 Mg C-1. About 5 Pg C could be achieved, at a cost less than $20 per Mg C. Negative cost potential indicates that non-carbon revenue is sufficient to offset direct costs of these options. The achievable potential is likely to be smaller, however, due to market, institutional, and sociocultural barriers that can delay or prevent the implementation of the analyzed options. 相似文献
23.
D. Costa A. Borrell E. Margarit A. Carrió A. Soler I. Balmes X. Estivill A. Fortuny 《黑龙江环境通报》1995,15(2):141-148
Fluid from pleural effusion (n=2) and cystic hygroma (n=7) was obtained from eight fetuses, between 13 and 32 weeks of pregnancy at the time when a conventional prenatal diagnosis procedure was carried out. As these fluids contain lymphocytes, they were processed like peripheral blood. A karyotype was obtained in 4 days in both cases of pleural effusion and in four out of seven samples of cystic hygroma. An abnormal karyotype was detected in three of the four samples of cystic hygroma: two trisomies 21 and a monosomy X. Different parameters were evaluated in order to predict the feasibility of obtaining a cytogenetic diagnosis. Our data showed that if the amount of fluid obtained was ⩾4 ml and the initial lymphocyte count (ILC) was >0.2 × 106 cells/ml, a cytogenetic diagnosis was possible from an initial concentration of cultured lymphocytes )ICCL) of >0.06 × 106 cells/ml. 相似文献
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D. E. Barb J. F. Cruise X. Mo 《Journal of the American Water Resources Association》1996,32(3):511-519
ABSTRACT: A model for urban stormwater quality was developed in this study. The basis for the model is the process by which pollutants build up on the watershed surface. For the wet climate of the study site, it was assumed that there exists an interval of time over which the pollutant buildup equals the pollutant washoff (no accumulation of pollutant). The buildup model was represented by a linear function of the antecedent dry time. The buildup function was then linked with a pollutant washoff model represented by a power function of the storm runoff volume. Various time intervals for no net accumulation were tested to calibrate the model. The model was calibrated to observed data for two small urban basins in Baton Rouge, Louisiana, and model results were used to analyze the behavior of phosphorus concentrations in storm runoff from these basins over a long period of time. 相似文献
26.
Thermal and mechanical properties of poly(lactic Acid) and poly(ethylene/butylene Succinate) blends 总被引:2,自引:0,他引:2
In this study, blends of poly (lactic acid) (PLA) with poly(ethylene/butylene succinate) (Bionolle) have been investigated
for their thermal and mechanical properties as a function of the concentration of Bionolle. Differential scanning calorimetry
(DSC), dynamic mechanical analysis (DMA), and tensile tests were used to characterize the blends. From the results of the
DMA and DSC, it was found that this blend system was not miscible within the compositions studied. DSC results showed that
adding Bionolle aids in crystallization of PLA. It was observed that increasing the Bionolle concentration led to a slight
increase in the strain-at-break of the blends but a decrease in the Young’s modulus and ultimate tensile strength. Biaxially
oriented films showed an increase in tensile strength, modulus, and strain-at-break. 相似文献
27.
There are growing interests to use co-composted drilling wastes contaminated with hydrocarbons as growth media for planting in land reclamation. However, such use of the compost may have potential problems such as inherent toxicity of residual hydrocarbon and microbial N immobilization due to high compost C to N ratios. We investigated the growth, biomass production, N uptake, and foliar delta13C of white spruce (Picea glauca [Moench] Voss) seedlings in a pot experiment using 1-, 2-, 3-, and 4-yr-old composts (with different hydrocarbon concentrations and C to N ratios) and a local noncontaminated soil with (200 kg N ha(-1)) or without N fertilization. Growth and N content of seedlings (particularly N content in roots) were lower when grown in the compost media as compared with those grown in the soil. Within the compost treatments seedling growth was affected by compost age, but the magnitude of growth reduction was not linearly proportional to hydrocarbon concentrations. Plant N uptake increased with compost age, which corresponds with an increase in indigenous mineral N concentration. Effects of N fertilization on N uptake were curtailed by the presence of indigenous mineral N (e.g., in the 4-yr-old compost) and by fertilization-induced stimulation of microbial activities (e.g., in the 1-yr-old compost). The differences in foliar delta13C values between seedlings grown in compost and soil (P < 0.05) suggest that limitations on water uptake caused by the residual hydrocarbon might have been the predominant factor limiting seedling growth in the compost media. This study suggests that water stress caused by residual hydrocarbons may be a critical factor for the successful use of co-composted drilling wastes as a growth medium. 相似文献
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Christian Mougin Agnès Bouchez Laurence Denaix Isabelle Lamy François Laurent Fabrice Martin-Laurent Michel Mench 《Environmental science and pollution research international》2016,23(4):2974-2976
The fifth meeting of INRA’s national network of ecotoxicologists took place on 25 to 27 November 2014 in Biarritz, France. The main aim of the meeting was to bring together ecotoxicologists from INRA and associated partners, providing them ample opportunity to share and discuss their latest scientific results as well as the national policy of research in ecotoxicology and to precise perspectives for the network. 相似文献
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