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141.
Extracts from various vegetables and fruits were investigated for their abilities to reduce nitro-polycyclic aromatic hydrocarbons (NPAHs). The extracts from grape and onion exhibited an interesting selectivity, yielding corresponding hydroxylamines or amines as major products under mild conditions of 30 °C and pH 7.0. Grape extracts reduced the 4-nitro-1,8-naphthalic anhydride with the highest conversion rate (>99%) and the highest ratio of hydroxylamine to amine (95:5). In contrast, the onion extracts reduced 4-nitro-1,8-naphthalic anhydride with a conversion rate of 94% and a ratio of hydroxylamine to amine of 8:92. The thiol-reducing agent, β-mercaptoethanol, and metal cations, Ca2+ and Mg2+, greatly increased the reductive efficiency. This work provides an alternative strategy for biotransformation of nitro-polycyclic compounds. 相似文献
142.
针对食品工厂设计教学中存在的问题,笔者引入CDIO教学理念,并运用于该课程的教学改革中。通过该教学模式的实施,学生学习的积极性和主动性得到了很大提高,理论与实际相结合能力也有所增强,教学效果良好。 相似文献
143.
Quantitative feedback theory (QFT) is a powerful design technique for robust feedback control systems with plant uncertainties. In applying QFT to design robust feedback control systems, the generation of plant templates is an essential step. For a system with affinely dependent parameters and the parameter domain is a box, it is well known that the boundary of a plant template is included in the image of the set of edges of the parameter domain box. One can obtain the plant template from the image of the set of edges. However, this approach to the generation of the plant template leads to heavy computational burden since it wastes much computational effort computing the images of points on edges which lie in the interior of the plant template. In this paper, an efficient algorithm is proposed to identify, from an edge of the parameter domain box, the set of parameter points whose image lies in the interior of the plant template. The computational burden for generating the plant template thus can be obviously reduced by eliminating the identified sets of parameter points in the plant template generation procedure. Numerical examples are included to illustrate the efficiency of the algorithm. 相似文献
144.
为了量化评价园林植物景观美感,提出一种基于模糊集理论的园林植物景观美感自动评价模型,以园林植物景观的节能性、美观性、风景融合性以及节能环保性等参数为约束指标集,构建园林植物景观美感自动评价的模糊约束参量模型。采用层次分析方法进行园林景观美感评价的决策模型构建,通过模糊集理论进行评价模型的最优控制设计,将园林植物景观美感自动评价问题转换为求模糊集的二元规划问题。采用量化回归分析和主成分特征提取方法,实现园林植物景观美感的优化评价。实证分析结果表明,采用该方法进行园林植物景观美感评价的准确性较高,评价置信度水平较好。 相似文献
145.
T. Assefa B. Dagne W. Argaw D. Tessema S. Beebe 《The Journal of Agricultural Education and Extension》2013,19(5):497-512
AbstractPurpose: This research, conducted in Ethiopia, involved select stakeholders in the variety evaluation process early: to identify a greater number of acceptable varieties and to shorten a lengthy research and release process.Design/methodology/approach: A Participatory Plant Breeding (PPB) approach was used in both on-station and community-based trial evaluations. Farmers, traders and processors evaluated bean varieties for promotion, considering field performance, culinary characteristics, market value, and canning acceptability.Findings: Within four years, two varieties were identified and recommended for release which were high performing, had excellent consumption and cooking characteristics for local foods, fetched high local market prices and met international canning quality standards.Practical implications: (1) Ethiopian men and women have distinct criteria for evaluating white pea beans, the former putting emphasis on marketability, with women focusing on food security issues. Both groups might be involved in the selection process. (2) Key characteristics cited by farmers, for instance, use for forage, may not be taken into account in the formal breeding process. Expanding the criteria used to determine which varieties should be released would make economic sense. (3) Farmers screened for local product acceptability before researchers put forward lines for testing by the export and canning industry. Local acceptability need not necessarily conflict with market chain acceptability—if the right processes are followed.Originality/value: The context was unusual: a) the region was drought-prone; and b) the crop had to meet rigorous canning requirements, plus local preferences. The involvement of traders and processors was novel, as was the use of a ‘participatory framework’ even when the product had to meet stringent market requirements. 相似文献
146.
147.
园林绿化建设对于弱化石化工业区外显特征、修复遭受破坏的自然生态环境、构建生态园林式企业空间具有十分重要的意义.文章以泉港石化工业区为研究对象,针对其园林植物配置现状,从植物应用种类、配置模式、绿化效果等方面进行多角度的分析,总结了泉港石化工业区园林植物配置中存在的突出问题,探讨了相应的设计提升技术要点,以期为其后续的提升改造提供参考和借鉴. 相似文献
148.
分别以面部、楝果、辣蓼为主提取的植物农药对玉米螟防治效果明显,其中以辣蓼效果为最佳;而供试的5个玉米自交系之间的抗螟性差异显著。 相似文献
149.
针对当前食品工厂设计课程存在的主要问题,提出了课程教学改革和实践,优化理论教学内容、改进教学方法、强化实践性教学,以此提高学生的学习积极性。 相似文献
150.
官商之间--从周学熙与袁世凯北洋政权的关系看启新内部的官商关系 总被引：3，自引：0，他引：3
冯云琴 《河北师范大学学报(哲学社会科学版)》2003,26(4):127-132
近世中国沉沦的历程,也是中国逐步走向近代化的过程,而能否正确处理推动近代化进程最有力的两根杠杆——官与商的关系,则直接关系到近代化的成败。周学熙创办的启新洋灰公司在这方面提供了成功的范例。 相似文献