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31.
在简要介绍移动平均、傅立叶交换和小波变换基本原理的基础上,比较了它们在地球化学数据处理过程中去除噪声效果的优劣,并应用于塔北雅克松-轮台地区的地球化学勘探实际。研究结果表明,小波变换是一种理想的数据处理方法。 相似文献
32.
对废水污染源监测中影响监测数据代表性的主要因素进行了分析,并对提高废水污染源监测数据代表性提出了可行性建议。 相似文献
33.
The Kyoto Protocol is the first step towards achieving the objectives of the United Nations Framework Convention on Climate Change and aims among others to promote ‘the protection and enhancement of carbon sinks and reservoirs’. To encourage afforestation for carbon sequestration a project must be economically viable. This study uses a model to analyse the impact on project viability of a range of carbon monitoring options, international carbon credit value and discount rate, applied to a Pinus radiata afforestation project in New Zealand. Monitoring carbon in conjunction with conventional forest inventory shows the highest return. Long-term average carbon accounting has lower accounting costs, compared to annual and 5 yearly accounting, as monitoring is only required every 5–10 years until the long-term average is attained. In this study we conclude that monitoring soil carbon stocks is not economically feasible using any of the accounting methods, when carbon is valued at US$ 10/t. This conclusion may be relevant to forest carbon sequestration projects elsewhere in the world and suggests care is needed in selecting the appropriate carbon monitoring options to avoid the risk that costs could be higher than any monetary benefits from terrestrial carbon sequestration. This would remove any commercial incentive to afforest for carbon sequestration reasons and severely limit the use of forest sinks as part of any package of measures addressing the ultimate objective of the UNFCCC. 相似文献
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环境突发性事故采样的注意要点 总被引:2,自引:0,他引:2
根据环境突发性事故的特点,以作者工作经验,就事故采样的完整、典型,及时性以及样品保存4个方面,结合实例进行论述。 相似文献
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YEP采用了先进的计算机管理技术与电子邮件网络系统,到目前为止,省项目办和英国DRA咨询专家与世界银行和涉及YEP的各有关单位之间及时准确地进行了大量的数据传输工作,保证了YEP工作的顺利进行。 相似文献
40.
A survey was carried out to determine the effect of prenatal screening and therapeutic abortion on births in 1985 with anencephaly and spina bifida in England and Wales. Maternal serum alpha-fetoprotein tests were done on 399 288 women (60 per cent of pregnant women): 4 per cent were reported as being screen-positive and 1 per cent had an amniocentesis. An estimated 534 pregnancies associated with anencephaly were terminated and an estimated 445 pregnancies associated with spina bifida (but without anencephaly) were terminated. Most (63 per cent) of the anencephalic pregnancies were first suspected from an ultrasound examination; 57 per cent of the spina bifida pregnancies were first suspected from a positive maternal serum alpha-fetoprotein test, 35 per cent by ultrasound, and the remaining 8 per cent by other means. The birth prevalence of anencephaly declined by 94 per cent between 1964–1972 and 1985, but when the terminations of pregnancy on account of having a fetus with anencephaly are added to the births the decline in prevalence was only 50 per cent. The birth prevalence of spina bifida declined by 68 per cent over the same period but when the terminations were added to the births the decline in prevalence was only 32 per cent. Among births with anencephaly 66 per cent had had no screening or diagnostic tests in early pregnancy, but in those that did nearly all were positive–usually in twin pregnancies where one fetus was affected but not the other. Among births with spina bifida, 48 per cent had no tests and in those that did the results were mainly negative. We conclude that in order to monitor adequately the national screening programme for anencephaly and spina bifida a special neural tube defects register should be formed. 相似文献