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961.
An orthogonally designed experiment was conducted to study the single and combined effects of N, P and K on phytoremediation of Cu-polluted soil by Indian mustard. Addition of fertilizer N and P significantly increased Indian mustard shoot yield. Two high treatments combined with N resulted in the highest yields, followed by low-P combined with N. In contrast, high P with no N gave no yield increase and K had no effect on yield of Indian mustard. Nitrogen and P increased the amount of chlorophyll in the leaves, indicating that the yield increases were due to enhanced photosynthesis. Nitrogen application had no effect on plant Cu concentrations but addition of P slightly decreased plant Cu concentrations, likely a dilution effect resulting from the increase in yield. Among the treatments, N and P applied at 100 and 200 mg kg–1 respectively with no K application resulted in the highest Cu uptake. Thus, a combination of low N and high P produced a yield increase in Indian mustard that was more than adequate to compensate for a slight decrease in Cu concentration, resulting in the highest Cu removal from the contaminated soil. 相似文献
962.
963.
试论湖北省伏旱的环流特征 总被引:3,自引:1,他引:2
通过对湖北省几个典型伏旱年的同期环流特征的分析,揭示了与湖北严重伏旱灾害密切联系的几中大气环流系统,并进行了分型。指出,造成严重伏旱的主要天气系统有西太平洋副热高压,西风带环流和西太平洋台风,并根据伏旱期大气环流的不同型式,将造成湖北伏旱的环流特征主要归结为两类,一是副高势力强盛,西伸强烈,稳定控制长江中下游地区;中高纬度向环流占优势;台风活动较少,另一类是副高压势力较弱,主体位于太平洋面上空,西 相似文献
964.
2-Methylene-1,3-dioxepane (MDP) was copolymerized with ethylene (E) at a pressure of approximately 1000 psi and a temperature of approximately 70°C with AIBN as the free radical initiator. The copolymers obtained, poly(MDP-co-E), were characterized by elemental analysis, IR, 1H-NMR and 13C-NMR spectroscopy, DSC, and GPC. The copolymers contained 2–15 mol% ester units. MDP was also copolymerized with styrene (S) at 120°C with di-t-butyl peroxide as the initiator to prepare the copolymer, poly(MDP-co-S). The number-average molecular weights of both types of copolymers were in the range of 6000 to 11,000, and the weight-average molecular weights were in the range of 9000 to 17,000. The melting temperatures of poly(MDP-co-E) decreased with increasing ester unit content in the copolymer. For the MDP-S copolymers, the glass transition temperatures decreased with increasing ester unit content. Both poly(MDP-co-E) and poly(MDP-co-S) were degraded by methanolysis, and their molecular weights decreased by the expected amounts based on the ester unit content. 相似文献
965.
Three agreements addressing environmental and safety performance, zero discharge of wastewater and sustainable development have been signed between Formosa Plastics Corporation, Texas (Formosa Plastics), and its former adversaries. The key element of the agreements is the improvement of the affected community. These agreements go beyond public information and beyond procedures for public participation. They have led to meaningful public participation and partnership and are unique in this respect. The following article explores the setup and results of each agreement. The initial agreement, the Blackburn-Formosa Agreement, signed in 1992, set the stage for subsequent partnerships. The Wilson-Formosa Zero Discharge Agreement followed in 1994. Finally, the Sustainable Development Agreement was signed by Jim Blackburn, Diane Wilson, and Formosa Plastics in late 1997. These agreements have proven very successful in avoiding disputes and helping improve company performance in environmental and safety issues. In many respects, these agreements offer a model for others in working with an affected community. 相似文献
966.
967.
人工神经网络在道路交通噪声预测中的应用 总被引:20,自引:3,他引:20
人工神经网络具有很强的预测功能,根据某公路交通噪声的实测数据,应用人工神经网络进行道路交通噪声的预测,经检验,计算值与实测值接近,从而为道路交通噪声的预测提供了一种新的途径。 相似文献
968.
969.
浅析洪湖水生资源的开发与生态保护 总被引:2,自引:0,他引:2
洪湖的环境保护不仅对洪湖生物资源的开发利用,而且对洪湖地区的生态农业建设都起着重要作用。通过对洪湖的污染现状分析与防治对策研究,探索建设内陆淡水湖泊生态农业的途径。 相似文献
970.