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141.
The black soldier fly (BSF), Hermetia illucens, has been considered impressive as a saprophagous insect, for its high ability to convert organic waste to insect protein and oil. Hence, it has been regarded by the municipal administration that BSF might be used as a medium to deal with food waste. However, food waste in China has been characterized as having a high salt content, oily, and very spicy, which usually renders them unsuitable for animal feeding. In order to assess the technological reliability for BSF conversion of food waste, the tolerance of BSF for pH values, pungency, and NaCl in food were investigated in this case. Results indicated that strong acidity (pH = 3) was not good for the development of BSF, demonstrating less body weight and eclosion failure. In contrast, strong basicity (pH = 11) seemed to be beneficial for larval development with high biomass, and there is no difference in pupation, eclosion, larval biomass, and livability for BSF for pH values between 5 and 11. With regards to salinity, liner correlations were observed; the salinity strength increased along with the extension of the larval phase, but body weight, pupation rate, emerging rate, and livability were still consistent under 6% density of salinity. Influence of pungency on BSF larvae has not yet been found. In conclusion, BSF showed a high tolerance to pH value, pungency, and salinity in foodstuffs. Hence, it is expected that food waste from common environments might have a lesser possibility to cause negative effects on BSF development, which could be good news for BSF conversion technology. As for the process design, the conclusion suggested that food waste optimum for BSF is expected to be alkaline and low-salt, which would be helpful to improve the efficiency and harvest. © 2018 Science Press. All rights reserved. 相似文献
142.
虽然人类社会不断进步发展,但大量工业和自然排放也导致了严重的空气污染。大气颗粒物是大气污染物的主要成分之一,黑碳是其中的重要组成成分,被国际癌症研究机构(IARC)归类为2B类致癌物。黑碳可以吸附其他致癌物质,会对环境和人体健康产生不利影响,因此黑碳暴露对人类的危害得到越来越多的重视。空气中黑碳的水平与心血管、呼吸和神经系统疾病的发生都有关系;黑碳主要通过引起氧化应激和炎症反应,诱发基因突变等一系列损伤。虽然现今对于黑碳健康效应的研究已取得了一些进展,但研究多数处于起步阶段,且仅针对黑碳本身进行单独研究,未来还需要加强开展对黑碳和其他污染物联合毒性效应及机制的研究。本综述主要针对近年来已开展的研究进行了总结归纳。 相似文献
143.
极值风速作为输电线路抗风设计的重要参数,对结构的强度和年限标准意义重大。为克服采用观测资料直接推算极值风速的缺陷,给出了一种沿海地区输电线路极值风速推算的数值方法,即以台风风场物理方程为基础,利用历史台风进行反演,验证风场模型的适应性,随后结合台风年鉴,采用模拟圆和Monte Carlo抽样模拟进行研究点最大风速序列计算,并根据极值III型Weibull分布进行极值风速的推算。最后以海口市为例,对该极值风速推算方法进行详细阐述,推算了海口市近100a内重现期的极值风速,并与观测统计值进行对比,研究发现本文模拟效果较好,可以作为沿海地区输电线路抗风设计的理论参照。 相似文献
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为解决人工神经网络(ANN)对复杂系统进行事故预测建模时,易导致网络复杂,降低网络性能和增大预测误差的问题,提出一种基于主成分分析法(PCA)的ANN事故预测方法。介绍PCA法和ANN的基本理论,阐述基于PCA法的ANN事故预测模型及其预测步骤,即在利用ANN预测之前,先用PCA法分析事故影响指标,将多个指标转化为少数几个能反映原始信息的互不相关的综合变量(主成分),然后以这些变量作为输入进行ANN建模,从而达到简化模型,提高网络性能和计算精度的目的。以煤矿事故预测为例,进行应用和对比研究。结果表明:基于PCA的ANN事故预测相对误差小于3%,而直接运用ANN方法预测的相对误差达到5%。这说明,对复杂安全系统进行事故预测时,基于PCA法的ANN预测方法是更可行的。 相似文献
146.
为得到地铁区间隧道竖井送风有效风量的无量纲计算模型,通过推导地铁区间隧道竖井送风有效风量的无量纲公式,并采用数值模拟方法明确竖井送风有效风量与火源功率、火源距离、阻塞比和竖井送风量之间的量化关系。结果表明:火源功率、火源距离与竖井送风有效风量之间不存在函数关系;阻塞比对竖井送风有效风量影响显著,随着阻塞比的增大,有效风量逐渐减小,单侧列车停靠时,无量纲有效风量Qe*与阻塞比β呈-1.08次方减小关系,两侧列车停靠时,无量纲有效风量Qe*与阻塞比β呈-0.22次方减小关系;有效风量随竖井送风风量的增大逐渐增大,且有效风量增大比例高于送风风量,单侧列车停靠时,无量纲有效风量与无量纲送风风量呈1.11次方增大关系,两侧列车停靠时,无量纲有效风量与无量纲送风风量呈1.07次方增大关系。 相似文献
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148.
The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct.Among the metallic ions investigated,the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial... 相似文献
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150.
Allelopathic inhibition on red tide microalgae Skeletonema costatum by five macroalgal extracts 总被引:1,自引:0,他引:1
Zhen An Zhenyu Wang Fengmin Li Zhijia Tian Hongying Hu 《Frontiers of Environmental Science & Engineering in China》2008,2(3):297-305
This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide
microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marine
macroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha clathrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC50, 120 h) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respectively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible
allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C3H4O2), and linolenic acid (C18H30O2) were the most likely allelochemicals in E. clathrata. 相似文献