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排序方式: 共有424条查询结果,搜索用时 117 毫秒
1.
阜阳电厂粉煤灰综合利用可行性研究 总被引:3,自引:0,他引:3
结合阜阳地区实际情况,从目前成熟的粉煤灰利用途径中,选择制水泥、建粉磨站、生产非煅烧粉煤灰轻骨料、轻质小砌块,以及筑路回填、灰场种植等处理利用项目,达到节约土地并获得好的经济效益和环境效益 相似文献
2.
Monitoring of nitrate (NO3-) and nitrite (NO2-) content in agricultural products in Slovenia has been carried out since 1996. The results of monitoring over the period 1996-2002 are presented. During this time 924 samples of 14 different agricultural products (potato, lettuce, apples, carrot, silage maize, cabbage, grapes, peaches, string beans, cereals, pears, cucumbers, strawberries and tomato) were analysed. The samples were taken at the time of maturity directly from growing sites and they were analysed using segmented flow analysis. The average nitrate contents were the highest in lettuce (1074 mg kg-1), cabbage (881 mg kg-1), string beans (298 mg kg-1) and carrot (264 mg kg-1), and they were moderately high in potato (158 mg kg-1), silage maize (122 mg kg-1), strawberries (94 mg kg-1), cucumbers (93 mg kg-1) and cereals (49 mg kg-1). Low nitrate contents (below 6 mg kg-1) were found in fruit (grapes, peaches, apples and pears) and tomato. With the exception of cereals (8.9 mg kg-1), apples (1.5 mg kg-1), potato (1.2 mg kg-1) and pears (1.0 mg kg-1) the content of nitrites did not exceed 0.5 mg kg-1. It may be concluded that the results of the monitoring were in most cases similar to the results of investigations obtained in other countries. 相似文献
3.
An easy pot incubation method for measuring nitrogen mineralization from easily decomposable organic material under well defined conditions 总被引:1,自引:0,他引:1
K. Thorup-Kristensen 《Nutrient Cycling in Agroecosystems》1994,38(3):239-247
A pot incubation method for measuring mineralization dynamics from fresh plant material was tested. The aim was to develop a method which under well-defined conditions could produce mineralization data suited for estimating model input parameters for nitrogen prediction models. The results showed that the water tension of the soil could be controlled easily and precisely by diffusion through porous ceramic cups, and that nitrogen mineralization or immobilization could be measured already after 15 days at 15°C. The results showed that for the incubated catch crop residues carbon, nitrogen and nitrate-N contents were the most important factors determining mineralization. No significant effects ould be ascribed to other parameters measured. 相似文献
4.
Judith M. Bradow 《Journal of chemical ecology》1993,19(6):1085-1108
Low-input, sustainable agriculture (LISA) systems can include soil incorporation of residues of weeds and legume cover crop species. However, both seed germination and seedling growth of crops, including cotton (Gossypium hirsutum L.), are inhibited by volatile organic compounds emitted by these residues during decomposition. A cotton seedling-growth assay was used to demonstrate that C4 through C9 ketones released by decomposing legume residues significantly inhibited root and shoot elongation, root and shoot fresh and dry weight gain, and cotyledon expansion. Seedling root and shoot water relationships were relatively insensitive to those components of plant residue volatile emissions. Concentration (0.0, 0.5, 1.0, 1.5, or 2.0M/cm3 sterile greenhouse soil mix) and root-zone temperature (20 or 30°C) altered the activity of the more inhibitory ketones. Molecular weight (carbon chain length), carbon chain branching, and position of the carbonyl group also influenced ketone inhibitory activity.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture. 相似文献
5.
Increased potassium fertilization may be important in broccoli transplant growth. Recommended amounts of water soluble 20N-8.7P-16.6K were supplemented with varying concentrations of K as KCl applied at intervals during broccoli transplant development. Transplant growth and subsequent broccoli yields were studied in greenhouse and field tests.Fertilization with supplemental K significantly increased broccoli transplant fresh and dry weight, leaf area, stem diameter and plant height over the control. Effect of number of applications was generally dependent on K concentration and age of the broccoli seedling at the first fertilization. High K concentrations (> 2098 ppm) applied two weeks after planting were detrimental to broccoli transplant growth.In two field tests, supplemental K applied to transplants had no effect on broccoli yield. No significant differences were found between supplementing fertilizer with K and hardening transplants in a cold frame for two weeks. Incidence of hollow stem was increased in one test by application of 1000ppm K. Two applications per week caused significant increases in yield, head diameter and hollow stem when compared with one application per week. 相似文献
6.
锶是人体必不可少的微量元素之一,前人对承德地区土壤和农作物中锶的研究很少。本文通过测定承德地区1200 件表层土壤和多种农作物及中药材的根、茎、叶、花、果实等样品中锶含量,发现承德地区土壤中的锶含量较高,但具有分布不均匀的特征。土壤锶分布受深大断裂控制,同时与岩性关系密切,特别是火成岩建造。农作物中锶的含量为0.77~26.60 mg/kg,主要分布在根、茎、叶等部位。19 种中药材中锶含量最高的黄芪叶锶含量高达116 mg/kg。不同种类的农作物富集锶的能力不同。总体来讲,中药材中锶含量要高于叶菜类,叶菜类锶高于粮食作物类,粮食作物类锶含量高于水果类。采用浇灌不同浓度的含锶水试验,在一定的浓度下,对小白菜中锶含量有一定的增加作用。浇灌同等量的锶浓度水的情况下,幼苗期、成熟期、衰老期,土壤锶高的小白菜中锶含量高于土壤锶低的小白菜中锶含量。本文通过测定承德地区土壤和农作物中锶含量,查明本地区土壤和农作物中锶的分布规律,为特色功能农产品的开发提供科学依据。 相似文献
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8.
数据库是计算机智能决策支持系统的核心。文章介绍了智能数据库设计系统的结构,并以农作物中的水稻作物数据库为例,提出了具体的设计方法,分析了智能数据库管理的功能。 相似文献
9.
10.
Carolina Simó Clara Ibá?ez Alberto Valdés Alejandro Cifuentes Virginia García-Ca?as 《International journal of molecular sciences》2014,15(10):18941-18966
Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. 相似文献