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521.
西昌地区野生藜蒿资源的开发利用 总被引:5,自引:1,他引:5
作者根据对四川省西昌地区野生藜蒿资源的调查研究。论述了野生藜蒿的生物学特征,分布、开发利用价值,繁殖特性和经济效益,并提出了开发利用野生藜蒿资源的建议。 相似文献
522.
This article does not focus on adaptation or mitigation policy directly but on an allied opportunity that exists for the Pacific
Islands via the auspices of the Climate Convention, because the existing very costly energy systems used in the Pacific Island
region are fossil-fuel dependent. It is argued here that efforts can be made towards the development of energy systems that
are ecologically sustainable because Pacific Island nations are eligible to receive assistance to introduce renewable energy
technology and pursue energy conservation via implementation mechanisms of the Climate Convention and, in particular, through
transfer of technology and via joint implementation.
It is contended that assistance in the form of finance, technology, and human resource development from developed countries
and international organizations would provide sustainable benefits in improving the local Pacific Island environments. It
is also emphasized that mitigation of greenhouse gas emissions is not the responsibility of the Pacific Islands as they contribute
very little on a per capita global scale and a tiny proportion of total global greenhouse gas emissions. 相似文献
523.
Demonstration of Line Transect Methodologies to Estimate Urban Gray Squirrel Density 总被引:2,自引:0,他引:2
Eric W. Hein 《Environmental management》1997,21(6):943-947
Sciurus carolinensis ) have been labor intensive and costly, I demonstrate the use of line transect surveys to estimate gray squirrel density and
determine the costs of conducting surveys to achieve precise estimates. Density estimates are based on four transects that
were surveyed five times from 30 June to 9 July 1994. Using the program DISTANCE, I estimated there were 4.7 (95% CI = 1.86–11.92)
gray squirrels/ha on the Clemson University campus. Eleven additional surveys would have decreased the percent coefficient
of variation from 30% to 20% and would have cost approximately $114. Estimating urban gray squirrel density using line transect
surveys is cost effective and can provide unbiased estimates of density, provided that none of the assumptions of distance
sampling theory are violated. 相似文献
524.
Paul V Bolstad Wayne T Swank 《Journal of the American Water Resources Association》1997,33(3):519-533
ABSTRACT: Water quality variables were sampled over 109 weeks along Coweeta Creek, a fifth-order stream located in the Appalachian mountains of western North Carolina. The purpose of this study was to observe any changes in water quality, over a range of flow conditions, with concomitant downstream changes in the mix of landuses. Variables sampled include pH, HCO32?, conductivity, NO3??-N, NH4+-N, PO43?-P, C1?-, Na, K, Ca2+, Mg2+, SO42?, 5iO2, turbidity, temperature, dissolved oxygen, total and fecal coliform, and focal streptococcus. Landcover/landuse was interpreted from 1:20,000 aerial photographs and entered in a GIS, along with information on total and paved road length, building location and density, catchment boundaries, hydrography, and slope. Linear regressions were performed to relate basin and near-stream landscape variables to water quality. Consistent, cumulative, downstream changes in water quality variables were observed along Coweeta Creek, concomitant with downstream, human-caused changes in landuse. Furthermore, larger downstream changes in water quality variables were observed during stormflow when compared to baseflow, suggesting cumulative impacts due to landscape alteration under study conditions were much greater during storm events. Although most water quality regulations, legislation, and sampling are promulgated for baseflow conditions, this work indicates they should also consider the cumulative impacts of physical, chemical, and biological water quality during stormflow. 相似文献
525.
许东强 《中国安全科学学报》1996,(Z1)
任何事故的发生都离不开人的不安全行为和物的不安全状态,作为危险性较大的冲压设备机械的伤害事故的产生也不例外。为此,从冲压设备机械伤害事故的两起案例入手,具体分析形成事故的因素并提出预防事故发生的有效措施。 相似文献
526.
废水中甲酸萃取回收的研究 总被引:9,自引:1,他引:9
以ZYM混合溶剂为萃取剂,以含4.5%的甲酸的废水进行萃取试验,结果表明,ZYM具有良好的热稳定性和再生性,对废水中的甲酸有较高的萃取率。采用本萃取技术,不但具有显著的环境效益,而且还可回收甲酸,获得较好的经济效益。 相似文献
527.
528.
本文报道了利用造纸黑液回收电镀废液中铬的方法,阐明了造纸黑液中所含有还原性物质与Cr^6+的反应机理;讨论了进行反应的最佳条件以及采用这一方法对废液的治理效果。 相似文献
529.
三峡工程移民卫生防病现状调查报告 总被引:3,自引:0,他引:3
本文报道了三峡工程四川库区移民安置区的自然疫源性疾病,虫媒传染病,介水传染病和地方病等的目前流行态势和环境卫生状况;预测了移民过程中地潜在危险,针对存在的问题,指出加强移民的卫生防病,对保护移民健康,保障移民工作顺利进行了是十分重要的。 相似文献
530.