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981.
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983.
An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO2) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO2 abatement costs and an incremental cost curve for CO2 mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO2 emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants.  相似文献   
984.
南海东北部考洲洋海洋渔业环境质量评价   总被引:2,自引:2,他引:2  
根据1999年考洲洋12个调查站的观测资料,按我国有关的环境质量标准,用质量指数法分级评价考洲洋的环境质量。结果表明:考洲洋的环境质量总体较好,但轻微污染偶有发生,石油类是主要污染物,其次为PO4-P。2月(枯水期)在5测站的表层沉积物中有机质含量略有超标,3测站海水和2测站表层沉积物受石油类轻污染,1测站的海水受Cu轻污染。8月(丰水期),5测站的海水受PO4-P轻污染。  相似文献   
985.
本文讨论了在高纬度地区公司所起的作用,它被概念化为以社会和经济为媒介的生态系统,同时指出了商业环境里其他的一些重要的社会参与者.我们列举了高纬地区企业行为的三个案例并对其中各种共性进行了讨论.特别的,我们认为有必要对商业理论和实践进行革新,以使其不只是停留在社会与经济概念的组织恢复力上,而要把高纬地区的生态恢复力也包括到商业管理的目标之中.同时我们也认为区域生态系统的恢复力应该成为衡量企业可持续管理的一个有意义的指标,企业高层可以据此制定和修改企业的管理策略.最后,文章在结尾处呼吁对高纬地区内的跨国公司和国内公司的作用制定更为详细的研究议程.  相似文献   
986.
The climate impact from the useof peat for energy production in Sweden hasbeen evaluated in terms of contribution toatmospheric radiative forcing. This wasdone by attempting to answer the question`What will be the climate impact if onewould use 1 m2 of mire for peatextraction during 20 years?'. Two differentmethods of after-treatment were studied:afforestation and restoration of wetland.The climate impact from a peatland –wetland scenario and a peatland –forestation – bioenergy scenario wascompared to the climate impact from coal,natural gas and forest residues.Sensitivity analyses were performed toevaluate which parameters that areimportant to take into consideration inorder to minimize the climate impact frompeat utilisation. In a `multiple generationscenario' we investigate the climate impactif 1 Mega Joule (MJ) of energy is produced every yearfor 300 years from peat compared to otherenergy sources.The main conclusions from the study are:?The accumulated radiative forcing from the peatland – forestation – bioenergy scenario over a long time perspective (300 years) is estimated to be 1.35 mJ/m2/m2 extraction area assuming a medium-high forest growth rate and medium original methane emissions from the virgin mire. This is below the corresponding values for coal 3.13 mJ/ m2/ m2 extraction area and natural gas, 1.71 mJ/ m2/ m2 extraction area, but higher than the value for forest residues, 0.42 mJ/ m2/ m2 extraction area. A `best-best-case' scenario, i.e. with high forest growth rate combined with high `avoided' methane (CH4) emissions, will generate accumulated radiative forcing comparable to using forest residues for energy production. A `worst-worst-case' scenario, with low growth rate and low `avoided' CH4 emissions, will generate radiative forcing somewhere in between natural gas and coal.?The accumulated radiative forcing from the peatland – wetland scenario over a 300-year perspective is estimated to be 0.73 –1.80 mJ/ m2/ m2 extraction area depending on the assumed carbon (C) uptake rates for the wetland and assuming a medium-high methane emissions from a restored wetland. The corresponding values for coal is 1.88 mJ/ m2/ m2 extraction area, for natural gas 1.06 mJ/ m2/ m2 extraction area and for forest residues 0.10 mJ/ m2/ m2 extraction area. A `best-best-case' scenario (i.e. with high carbon dioxide CO2-uptake combined with high `avoided' CH4 emissions and low methane emissions from the restored wetland) will generate accumulated radiative forcing that decreases and reaches zero after 240 years. A `worst-worst-case' (i.e. with low CO2-uptake combined with low `avoided' CH4 emissions and high methane emissions from the restored wetland) will generate radiative forcing higher than coal over the entire time period.?The accumulated radiative forcing in the `multiple generations' – scenarios over a 300-year perspective producing 1 MJ/year is estimated to be 0.089 mJ/ m2 for the scenario `Peat forestation – bioenergy', 0.097 mJ/ m2 for the scenario `Peat wetland with high CO2-uptake' and 0.140 mJ/ m2 for the scenario `Peat wetland with low CO2-uptake'. Corresponding values for coal is 0.160 mJ/ m2, for natural gas 0.083 mJ/ m2 and for forest residues 0.015 mJ/ m2. Using a longer time perspective than 300 years will result in lower accumulated radiative forcing from the scenario `Peat wetland with high CO2-uptake'. This is due to the negative instantaneous forcing that occurs after 200 years for each added generation.?It is important to consider CH4 emissions from the virgin mire when choosing mires for utilization. Low original methane emissions give significantly higher total climate impact than high original emissions do.?Afforestation on areas previously used for peat extraction should be performed in a way that gives a high forest growth rate, both for the extraction area and the surrounding area. A high forest growth rate gives lower climate impact than a low forest growth rate.?There are great uncertainties related to the data used for emissions and uptake of greenhouse gases in restored wetlands. The mechanisms affecting these emissions and uptake should be studied further.  相似文献   
987.
988.
True structural chromosomal mosaicism are rare events in prenatal cytogenetics practice and may lead to diagnostic and prognostic problems. Here is described the case of a fetus carrying an abnormal chromosome 15 made of a whole chromosome 2p translocated on its short arm in 10% of the cells, in association with a normal cell line. The fetal karyotype was 46,XX,add(15)(p10).ish t(2;15)(p10;q10)(WCP2+)[3]/46,XX[27]. Pregnancy was terminated and fetus examination revealed a growth retardation associated with a dysmorphism including dolichocephaly, hypertelorism, high forehead, low-set ears with prominent anthelix and a small nose, which were characteristic of partial trisomy 2p. Possible aetiologies for prenatal mosaicism involving a chromosomal structural abnormality are discussed. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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990.
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