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891.
高浓度褐藻酸钠生产废水处理工程设计 总被引:5,自引:0,他引:5
利用以EGSB反应器为主体的生物法与混凝工艺相结合处理高浓度褐藻酸钠生产废水,处理水质可达到国家污水综合排放二级标准。工程实践表明该工艺具有投资与占地面积少,运行效果稳定,可回收能源等优点。 相似文献
892.
南京城市环境景观设计与建设的思路及实践 总被引:1,自引:0,他引:1
城市环境景观是指能集中体现城市环境状况和整体形象的基础设施、建筑等,它对提高城市的生活质量、文化品味及投资环境具有重要意义,并将成为今后城市之间比较的重要指标。本文以“南京市市容环境卫生发展规划”工作为基础,引入城市环境景观的理念,分析南京城市环境景观的现状及存在的问题,如缺少标志性建筑与雕塑、夜景与亮化无特色,高层建筑外观和户外广告疏于管理等,进而提出南京城市环境景观设计的具体方案和建设思路,包括开发风景带,设计和建设精品建筑,加强绿化,规范户外广告等。 相似文献
893.
全基因合成方法学研究 总被引:2,自引:0,他引:2
通过基因全合成实现基因的分子改造和人工组建正成为一种实验室常规手段,因此,建立一种能够在相对低廉和短时间内准确和高效地设计和合成长片段基因的方法十分重要.本研究报道了一种重复性好、错误率低、低成本和简便的基因设计和全合成方法.此方法包含经DNA2.0软件的序列优化,Gene2Oligo软件的寡核苷酸设计,覆盖全长基因双链的寡核苷酸的组合和引物介导下的全基因的合成等步骤.运用此方法,对3个不同长度的基因(分别为653bp,1309bp和1498bp)成功地进行了密码子优化和一步全合成.其中的amyFF在大肠杆菌中表达量提高了12倍.图2参18 相似文献
894.
Order restricted randomized designs and two sample inference 总被引:1,自引:0,他引:1
This paper develops a new design that relies on subjective judgment ranking to compare subsets of experimental units. This
judgment ranking is used along with restricted randomization to improve statistical inference for the contrast between two
levels of a treatment. The new design assigns the judgment ranked units in a subset to different treatments. Such an assignment
translates the positive dependence among units within each subset into negative dependence for the estimators of treatment
means, and hence leads to a reduction in variance for the contrast. For the proposed design, a test for the difference in
means of two treatment levels is developed along with an associated confidence interval. It is shown that the null distribution
of the proposed test is approximated reasonably well with the Student’s t-distribution for sample sizes as small as 6. A simulation study indicates that the proposed design is advantageous compared
to its competitors in the literature for both high and low quality rankings. The new design’s advantage increases with the
quality of rankings. 相似文献
895.
Objectives for Multiple-Species Conservation Planning 总被引:2,自引:0,他引:2
Abstract: The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat. Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities had to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals. 相似文献
896.
Experimental design of Fenton and photo-Fenton reactions for the treatment of cellulose bleaching effluents 总被引:1,自引:0,他引:1
Multivariate experimental design was applied to the treatment of a cellulose conventional bleaching effluent in order to evaluate the use of the Fenton reagent under solar light irradiation. The effluent was characterised by the general parameters total organic carbon (TOC), chemical oxygen demand and color, and it was analysed for chlorinated low molecular weight compounds using GC–MS. The main parameters that govern the complex reactive system: Fe(II) and H2O2 initial concentration, and temperature were simultaneously studied. Factorial experimental design allowed to assign the weight of each variable in the TOC removal after 15 min of reaction. Temperature had an important effect in the organic matter degradation, especially when the ratio of Fenton reagents was not properly chosen. Fenton reagent under solar irradiation proved to be highly effective for these types of wastewaters. A 90% TOC reduction was achieved in only 15 min of treatment. In addition, the GC–MS analysis showed the elimination of the chlorinated organic compounds initially detected in the studied bleaching effluents. 相似文献
897.
影响电除尘器高效持久运行的关键因素 总被引:1,自引:1,他引:1
通过萍乡矿业集团公司水泥厂使用电除尘器的情况 ,总结在实际应用中电除尘器高效持久运行必须具备的条件和应采取的措施 相似文献
898.
简易湿法石灰/石灰石烟气脱硫工艺设计及实践 总被引:2,自引:0,他引:2
在国家实施“总量控制”和“两控区”的重要环境保护政策下,烟气脱硫已势在必行。阐述了一种简易湿法烟气脱硫技术的系统设计、工艺流程及该技术的综合评价。 相似文献
899.
从对讲机外壳造型设计的实际应用出发,在分别讨论正向设计和逆向设计的基础上,提出将两者有机结合的CAD建模方法,并详细分析了其集成技术。最后,给出了一个应用实例,表明该技术方法的可行性和有效性,从而为产品创新设计提供了一条重要途径。 相似文献
900.