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81.
添加剂对垃圾焚烧飞灰熔融特性的影响   总被引:4,自引:2,他引:2  
研究制备了1种具有多重作用效果的飞灰熔融复合型添加剂,并选用上海和福州2种典型飞灰,利用荧光光谱仪和电感耦合等离子体质谱仪等仪器,分析了添加剂对飞灰熔融过程中的挥发率,流动温度,重金属固定率以及熔融渣的重金属浸出特性的影响.结果表明,添加10%添加剂可以将飞灰的流动温度降低150℃左右,挥发率降低10%~20%,重金属Cu和Pb的固定率提高了10%~20%,对重金属Zn的固定率可提高近40%;同时,采用我国毒性浸出方法和美国EPA的TCLP方法,分析测试熔融渣中重金属浸出量,结果证实几种重金属的浸出浓度均低于相应的标准限值.  相似文献   
82.
低聚糖或称寡糖是由2-10个单糖分子通过糖苷键连接组成的小聚合体。作为一种新型的功能性饲料添加剂,在动物体内可促进消化道有益菌的生长,抑制有害病原菌的繁殖,提高动物机体免疫力。多数试验研究表明,饲料中添加适量低聚糖,能在较大程度上替代抗生素而改善动物健康,增强抗病力,提高家禽及幼龄动物成活率,提高动物的生长增重和饲料转化率。  相似文献   
83.
Abstract:  The management of tropical forest in timber concessions has been proposed as a solution to prevent further biodiversity loss. The effectiveness of this strategy will likely depend on species-specific, population-level responses to logging. We conducted a survey (749 line transects over 3450 km) in logging concessions (1.2 million ha) in the northern Republic of Congo to examine the impact of logging on large mammal populations, including endangered species such as the elephant ( Loxodonta africana ), gorilla ( Gorilla gorilla ), chimpanzee ( Pan troglodytes ), and bongo ( Tragelaphus eurycerus ). When we estimated species abundance without consideration of transect characteristics, species abundances in logged and unlogged forests were not different for most species. When we modeled the data with a hurdle model approach, however, analyzing species presence and conditional abundance separately with generalized additive models and then combining them to calculate the mean species abundance, species abundance varied strongly depending on transect characteristics. The mean species abundance was often related to the distance to unlogged forest, which suggests that intact forest serves as source habitat for several species. The mean species abundance responded nonlinearly to logging history, changing over 30 years as the forest recovered from logging. Finally the distance away from roads, natural forest clearings, and villages also determined the abundance of mammals. Our results suggest that logged forest can extend the conservation estate for many of Central Africa's most threatened species if managed appropriately. In addition to limiting hunting, logging concessions must be large, contain patches of unlogged forest, and include forest with different logging histories.  相似文献   
84.
含微胶囊添加剂的低压细水雾厨房灭火实验研究   总被引:1,自引:1,他引:0  
通过全尺寸实验研究低压细水雾对抑制和熄灭K类火灾的有效性。选用三种喷头进行灭火实验,并选择灭火效果最好的喷头进行含微胶囊F-500添加剂的细水雾灭火实验。结果表明,低压细水雾对抑制和熄灭食用油火灾具有一定的效果,但容易发生复燃。而添加了微胶囊F-500的低压细水雾,灭火效率较纯细水雾提高约3~10倍,且能有效地避免复燃,同时提高了火场的能见度。不同浓度的F-500溶液具有不同的灭火效果,综合考虑经济性和有效性因素,3%浓度的F-500溶液是厨房低压细水雾灭火系统的最佳灭火介质。  相似文献   
85.
文章探讨了添加剂F127的质量百分含量(5%、7%、10%和13%)对CPVC超滤膜微观结构及其性能(包括水通量、截留率、机械性能、亲水性和耐污染性能)的影响.结果表明:随着F127含量的增加,铸膜液剪切粘度增加,截留率上升,亲水性和耐污染性能大幅度提高,纯水通量和机械性能有所下降.综合比较添加剂F127含量为10%时,CPVC超滤膜性能较好.  相似文献   
86.
87.
天然沸石对土壤镉及番茄生物量的影响   总被引:1,自引:0,他引:1  
为了探索沸石对轻度镉污染土壤的修复效果及对番茄生长的影响,利用盆栽试验研究了不同沸石添加量及不同沸石粒级等因素对不同生长时期番茄(Solanum lycopersicum)植株生物量、果实产量和土壤镉质量分数的影响。结果表明,添加沸石均不同程度地提高不同生长期番茄地上部生物量和果实产量;每千克土壤添加10 g的大粒级(MX)沸石使得土壤全镉和有效镉增加最多,同时也使番茄果实增产最多,每千克土壤添加18 g的小粒级(MN)沸石使得土壤全镉质量分数有所降低,土壤有效镉质量分数增加最少,同时也可使番茄果实增产42.9%以上。小粒级(MN)沸石为削减土壤重金属镉的最佳沸石粒级,18 g.kg-1为削减土壤重金属镉的最佳沸石添加量。  相似文献   
88.
基于GAM模型的四川盆地臭氧时空分布特征及影响因素研究   总被引:4,自引:0,他引:4  
为研究四川盆地臭氧(O_3)时空分布特征及其气象成因,对四川盆地18个城市2015—2016年国控环境监测站点和气象台站数据进行了研究分析.结果表明:2015—2016年四川盆地O_3污染愈发严重,高值污染区呈扩张态势,污染区主要位于盆地西部成都、德阳、资阳、眉山、内江一带和以广安为中心的周边区域.O_3浓度有明显的季节变化特征:夏季(110.70±41.52)μg·m~(-3)春季(95.24±41.23)μg·m~(-3)秋季(67.58±39.55)μg·m~(-3)冬季(47.17±41.15)μg·m~(-3).基于广义相加模型(GAM)分析发现O_3浓度与气压、气温、相对湿度、风速、日照时数、降水量间均呈非线性关系,其中日照时数、相对湿度以及气温对四川盆地O_3浓度影响较大,而风速、气压以及降水量对O_3浓度影响相对较小.通过构建GAM模型对四川盆地18个城市O_3污染的主导气象因子进行识别,并对2017年O_3浓度进行预测和检验,结果显示GAM模型能较为准确地预测四川盆地各城市O_3浓度的变化趋势.  相似文献   
89.
In this study, we investigated the suppressive effect of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) transfer from the feed to the eggs of laying hens by using activated carbon as a feed additive. Four groups of six hens (White Leghorn egg-layers; age, 11 weeks) were housed as two control groups and two exposure groups for a period of 20 weeks. Two control groups were fed with either the basal feed “Control” or basal feed additing activated carbon “Control + C”. Another two exposure groups were fed with feed contaminated (about 6 ng TEQ kg−1 feed) by standard solutions of PCDDs/PCDFs and DL-PCBs “Exposure” alone and contaminated feed adding activated carbon “Exposure + C”. There was no significant effect on each groups for the growth rate, biochemical blood components, and egg production: these were around the standard levels for poultry in general. Moreover the results in this study showed the availability of activated carbon as a feed additive owing to the reduction in the risk of food pollution by PCDDs/PCDFs and DL-PCBs. The concentration in the eggs of the Exposure group gradually increased following the start of egg-laying but reached a steady state after about 1 month. In contrast, the concentration for the Exposure + C group was stationary and below the maximum EU level (6 pg TEQ g−1 fat). In comparison to the Exposure group, the Exposure + C group showed a significant decline in the percentage of bioaccumulation into the egg. This reduction due to activated carbon was also observed in the muscle and abdominal fat. The reductions were compound- and congener-dependent for DL-PCBs as follows: PCDDs/PCDFs, non-ortho-PCBs, and mono-ortho-PCBs were more than 90%, 80%, and 50%, respectively, irrespective of the type of tissues. Fat soluble vitamin concentrations in the eggs of the Exposure + C group showed lower trends than the Exposure group. The γ-tocopherol and α-tocopherol concentrations in eggs of Exposure + C group showed a significant reduction of about 40%. However, the addition of activated carbon into animal feed could obviate the remote potential for accidents causing unintentional food pollution with PCDDs/PCDFs and DL-PCBs.  相似文献   
90.
通风条件对城市污水厂污泥好氧堆肥过程的影响   总被引:2,自引:0,他引:2  
本文选择堆肥熟料作为添加剂与城市污水厂污泥混合进行好氧堆肥。通过对温度、耗氧速率、有机物、含水率、pH值和氨氮等指标的分析,重点研究了不同通风条件对堆肥过程的影响。实验结果表明,污泥与熟料混合后,有机物含量较低,堆肥速率较快,对通风条件的改变比较敏感。当通风量低于0.025m3/(m3.min)时,堆肥前期系统供氧不足,堆肥速率较慢,耗时长,同时堆体内变为厌氧环境,pH值变低,臭气产生量高;当通风量高于0.05m3/(m3.min)以及采用变风量通风时,在保证供氧量充足的同时,具有较长的高温期,具有臭气产生量小、堆肥速率快的优点,但采用变风量通风更加节能。  相似文献   
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