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71.
昆明市城市污水污泥的肥效及其资源化利用 总被引:7,自引:0,他引:7
目前昆明市处理城市污水36.5万m^3/d,同时产生污泥130t/d,至2000年,污泥的数量还会增加至220t/d左右,如处置不当,极易造成二次污染。通过污泥成分分析,发现污泥中含有植物生长所需的大量营养元素,可用于花卉园林栽培,既满足了日益发展的园林产业的需要,又为污泥的消纳和利用找到一条合理的途径。 相似文献
72.
安全控制系统与FSC 总被引:3,自引:2,他引:3
随着社会的发展,人们对生产安全的要求越来越高,本文介绍了安全控制在工业生产,特别是在石油、化工生产中的重要性和安全控制系统从简单到复杂的发展过程,并着重介绍了Honeywell公司生产的故障安全控制系统(FSC-Fail safety control)的特点与应用。 相似文献
73.
Phosphorusavailabilityintwosoilsamendedwithpoultrylitter¥HanXingguo(InstituteofBotany,ChineseAcademyofSciences,Beijing100093,... 相似文献
74.
IntroductionCyanobacteria(i .e .Microcystis aeruginosa) blooms arefrequently associated withchanges of zooplanktoncommunity.Fewzooplanktons can use bloom-formingMicrocystisdirectlybecause of nutritional deficiencies ( Arnold, 1971 ) ,inedibility( Webster … 相似文献
75.
土壤中有效态稀土元素提取剂的选择 总被引:7,自引:0,他引:7
通过0.01mol/LHCl,0.05mol/LHCl,1.0mol/L NH4Oac(pH7.0),1.0mol/LNH4NO3(pH7.0),1.0mol/LHOAc/NH4Oac(pH4.8),1.0mol/LNH4Cl(pH7.0)6种提取剂对20种土壤中有效态稀土元素测定结果的比较,以及将测定结果同土壤特性、土壤中稀土元素形态进行相关分析,并通过黑麦草土培试验进行了生物评价,确定了1.0mol/LNH4NO3(pH7.0)为提取土壤中有效态稀土元素的最佳提取剂. 相似文献
76.
Ecological factors have been claimed paramount for the evolution and maintenance of cooperative group living in eusocial termites, as well as in cooperatively breeding birds and mammals. However, a clear demonstration of the role of any specific ecological factor in termites has been lacking. In the termite Cryptotermes secundus, individuals have two options, staying as helpers at the natal nest or developing into winged sexuals that disperse to found new colonies. An important ecological factor expected to influence the course of termite development is food availability; C. secundus nests inside a single piece of wood that serves as the sole source of food for the duration of the colony. As wood is consumed, the longevity of the colony is reduced, thus diminishing the potential fitness gains of staying at the nest. We experimentally investigated the occurrence of cooperative behavior and development under abundant- and limited-food conditions. Workers exposed to food-limited conditions were more likely to develop into dispersing sexuals and increased selfishly their food-acquisition behaviors. Proximately, a reduced frequency of proctodeal trophallaxis may have interfered with the distribution of pheromones that inhibit sexual development. Ultimately, decreased inclusive fitness benefits in food-limited, and thus short-lived nests, appear to explain the development of dispersing sexuals, supporting (1) the benefits-of-philopatry hypothesis as developed for the occurrence of cooperative breeding in vertebrates, and (2) predictions of reproductive skew theories.Communicated by L. Keller 相似文献
77.
长期不同施肥下灰漠土有机磷组分的变化 总被引:1,自引:0,他引:1
土壤有机磷是土壤磷素的重要供应源,也是植物吸收磷素的重要来源。对灰漠土16年长期不同施肥条件下,土壤有机磷的四种形态(活性有机磷、中活性有机磷、中稳性有机磷和高稳性有机磷)进行了测定。结果表明,不施磷肥处理(CK、N)土壤有机磷组分有下降趋势,施磷肥处理(NP、NPK和NPKM)可以提高有机磷各组分的含量,但是只有氮磷钾配合有机肥施用效果显著,有机磷总量和中活性有机磷提高了60%左右。不同施磷下灰漠土有机磷组分均以中活性有机磷为主,其占有机磷的比例为80%~90%;四种有机磷含量次序为中活性有机磷>中稳性有机磷>活性有机磷>高稳性有机磷。土壤有机磷组分中,活性和中活性有机磷含量与速效磷的相关性达极显著水平(相关系数分别为0.9403**,0.9894**;n=5),说明土壤活性有机磷和中活性有机磷有效性相对较高,是植物有效磷的主要形态。 相似文献
78.
酸性土壤有效态硒浸提方法的研究 总被引:5,自引:0,他引:5
本文提出了酸性土壤有效硒的0.1MKH_2PO_4浸提法.土壤和植物的分析结果表明:0.1MKH_2PO_4浸提有效态硒能反映土壤对植物的供硒状况.黑麦幼苗试验进一步证明KH_2PO_4浸提有效态硒可以作为酸性土壤有效硒的指标. 相似文献
79.
Dominic Bourassa Georges Abdul-Nour 《International journal of occupational safety and ergonomics》2016,22(1):131-141
Accidental events in manufacturing industries can be caused by many factors, including work methods, lack of training, equipment design, maintenance and reliability. This study is aimed at determining the contribution of failures of commonly used industrial equipment, such as machines, tools and material handling equipment, to the chain of causality of industrial accidents and incidents. Based on a case study which aimed at the analysis of an existing pulp and paper company's accident database, this paper examines the number, type and gravity of the failures involved in these events and their causes. Results from this study show that equipment failures had a major effect on the number and severity of accidents accounted for in the database: 272 out of 773 accidental events were related to equipment failure, where 13 of them had direct human consequences. Failures that contributed directly or indirectly to these events are analyzed. 相似文献
80.
Using the cumulative availability curve to assess the threat of mineral depletion: The case of lithium 总被引:2,自引:0,他引:2
The cumulative availability curve shows the quantities of a mineral commodity that can be recovered under current conditions from existing resources at various prices. The future availability of a mineral commodity depends on the shape of its cumulative availability curve (determined by geologic considerations, such as the nature and incidence of the available mineral deposits), the speed at which society moves up the curve (determined by future demand and the extent to which this demand is satisfied by recycling), and shifts in the curve (determined by cost-reducing technological change and other factors). While the shape of the curve for any given mineral commodity may or may not be known, it is knowable since the geologic processes responsible for the curve's shape took place many years ago. In contrast, the factors governing how fast society moves up the curve and how the curve shifts over time are not only unknown but also unknowable.Using lithium as an example, this article shows that knowledge about the shape of the cumulative availability curve can by itself provide useful insights for some mineral commodities regarding the potential future threat of shortages due to depletion. Despite the inherent uncertainties surrounding the future growth in lithium demand as well as the uncertainties regarding the future cost-reducing effects of new production technologies, the shape of the lithium cumulative availability curve indicates that depletion is not likely to pose a serious problem over the rest of this century and well beyond. 相似文献