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391.
利用脂肪酶提高鱼油中多不饱和脂肪酸(PUFAs)甘油酯 总被引:3,自引:0,他引:3
利用脂肪酶选择性的水解作用研究提高鱼油中多不饱和脂肪酸(PUFAs)甘油酯的含量.通过对5种不同来源脂肪酶的筛选,以来源于米曲霉脂肪酶为最佳酶种;同时研究该酶水解鱼油的最佳工艺条件:反应温度、加酶量、反应转速、添加剂影响;最后确定最佳的富集PUFAs甘油酯时间.在此工艺条件下,鱼油中EPA由3.0%提高到9.0%,DHA由4.3%提高到16.5%,EPA DHA由7.3%提高到25.5%.图3表1参8 相似文献
392.
温度和盐分对两种盐爪爪属植物种子萌发的影响 总被引:7,自引:0,他引:7
通过研究温度和NaCl对两种藜科叶肉质化盐生植物——里海盐爪爪和盐爪爪种子萌发的影响,显示出里海盐爪爪的最适萌发温度范围为20~30℃,而盐爪爪适合在变温条件下萌发,两者对温度的反应有显著差异;两者的萌发率和萌发速率都随NaCl浓度升高而降低,里海盐爪爪比盐爪爪的耐盐能力低;高盐分条件能诱导两个种的休眠,而当盐浓度降低时两者都能很好地恢复萌发,且萌发速率加快。因此,尽管里海盐爪爪仅能在低于300mmol/L,盐爪爪在低于400mmol//LNaCl浓度下萌发,这种耐盐能力低于很多盐生植物,但根据两个种所表现的综合萌发特性,它们依然被认为属于具有较高耐盐能力的盐生植物类型.图3表1参24 相似文献
393.
超高浓度萘系磺酸染料中间体废液资源化 总被引:1,自引:0,他引:1
王连生 《城市环境与城市生态》1995,8(3):11-14
本文介绍了胺盐萃取回收率液中萘磺酸染料中间体的方法,回收率达95%以上,回收浓缩液工艺套用,10t/d废液量的资源化年净效益达580万元,投资费用两个月即可全部收回,采用Langmuir等温方程描述体系中萃取剂用量,待萃物含量和萃取率的关系,使工艺参数的确立和工程设计完全处理指导之下。 相似文献
394.
Avril Siung-Chang 《Environmental geochemistry and health》1997,19(2):45-55
Marine pollution and coastal degradation have become serious development issues in the Caribbean. Early evidence of marine pollution was mainly anecdotal, but within the last 10--15 years, work conducted by universities and research institutions in the Region has provided the beginnings of a database that identifies several common marine pollution problems. The United Nations Environment Programme (UNEP), the Intergovernmental Oceanographic Commission (IOC) and the Pan American World Health Organization (PAHO/WHO) have also been instrumental in co-ordinating several marine pollution studies. In the English-speaking Caribbean, the University of the West Indies, the Institute of Marine Affairs in Trinidad and Tobago, and the Caribbean Environmental Health Institute located in St Lucia, have taken a lead role in identifying marine pollution problems in their Sub-Region. For the Wider Caribbean a database for petroleum pollution and marine debris has been developed. Land-based sources of marine pollution have been identified as a major problem, with several hot spots identified in mainland countries and in some of the larger industrialised islands. Organic and nutrient pollution, particularly from sewage, is most widespread and is possibly the most serious marine pollution problem in the Caribbean. A lack of capital investment funds to install the appropriate infrastructure to deal with sewage and other liquid effluents is a major stumbling block to solving the problem of marine pollution in the Caribbean. Other factors include political will and administrative and legal structures to regulate human development activities. 相似文献
395.
Vikram J. Kaku Michel C. Boufadel Albert D. Venosa James Weaver 《Environmental Fluid Mechanics》2006,6(4):385-406
The evaluation of dispersant effectiveness used for oil spills is commonly done using tests conducted in laboratory flasks.
We used a Hot Wire Anemometer (HWA) to characterize mixing dynamics in the Swirling Flask (SF) and the Baffled Flask (BF),
the latter is being considered by the EPA to replace the prior to test dispersant effectiveness in the laboratory. Five rotation
speeds of the orbital shaker carrying the flasks were considered, Ω = 50, 100, 150, 175 and 200 rpm. The radial and azimuthal
water speeds were measured for each Ω. It was found that the flow in the SF is, in general, two-dimensional changing from
horizontal at low Ω to axi-symmetric at high Ω. The flow in the BF appeared to be three-dimensional at all rotation speeds.
This indicates that the BF is more suitable for representing the (inherently) 3-D flow at sea. In the SF, the speeds and energy
dissipation rates ɛ increased gradually as the rotation speed increased. Those in the BF increased sharply at rotation speeds
greater than 150 rpm. At 200 rpm, the Kolmogorov scale (i.e., size of smallest eddies) was about 250 and 50 μm in the SF and
BF, respectively. Noting that the observed droplet sizes of dispersed oils range from 50 to 400 μm (hence most of it is less
than 250 μm), one concludes that the mixing in the SF (even at 200 rpm) is not representative of the vigorous mixing occurring
at sea. 相似文献
396.
大红色基G生产中产生的废硫酸内含硫酸达50%,COD70g/L,难用常规的方法来处理。本文给出了用该废酸生产硫酸锌进而生产立德粉的方法,并用COD浓度作为硫酸锌质量的控制指标,氧化锌和了废硫酸后,有机会物从溶液中析了,COD的去除率达99%。残存的有机物用活性炭吸附法除去。控制ZnSO4溶液中COD≤60mg/L,可制得合格的B301立德粉。有杉本法使硫酸资源全部回收并且无废水排放。 相似文献
397.
石油污染物进入土壤中后经历一系列物理化学和生物过程,其中发生的挥发过程是一种重要的迁移过程。本文以柴油为石油污染物的代表,研究了温度及土壤质地对柴油挥发行为的影响。通过在不同温度下纯柴油的挥发及柴油从四种不同土质的薄层土壤中的挥发试验,对柴油的挥发量与挥发时间的关系进行了模拟,结果表明:在不同温度下,纯柴油及柴油在四种薄层土壤中的挥发量与挥发时间的关系均可采用二次多项式来拟合。通过对比经相近时间柴油从4种不同土壤表面的挥发后,发现柴油挥发量均大于从纯柴油时的挥发量。在有机质质量分数不同的土壤中进行了柴油挥发试验,结果表明高有机质会抑制土壤中的柴油的挥发。 相似文献
398.
苔藓Lophozia ventricosa挥发油化学成分研究 总被引:1,自引:0,他引:1
采用水蒸气蒸馏法提取苔藓Lophozia ventricosa挥发油,用毛细管色谱法对挥发油进行了分析,采用归-化法确定各组分的相对含量,并用GC—MS联用技术对分离的化学成分进行鉴定.经计算机检索并结合文献调研,共鉴定出28个化合物,占挥发油总量的93.3%,其中含1个单萜、23个倍半萜(15个为含氧倍半萜)和1个二萜,主要成分为Maalioxide(45.6%)和Eudesma-4.(15),7(11)-dien-8-one(28.9%).图2表1参12 相似文献
399.
A. Cafissi S. Beduschi V. Balacco B. Sacchi S. P. Trasatti 《Environmental Chemistry Letters》2007,5(2):101-106
We studied the chemical dechlorination of the polychlorinated biphenyls (PCBs) in some dielectric oils via nucleophilic substitution
of the chloro atoms by polyethylene alkoxide. The influence of temperature, ultrasounds, polyethylene glycol (PEG) and base
type was investigated. Our findings show that dechlorination of PCBs by chemical treatment is effective at moderate temperature
(90–100°C) and is strongly dependent on the nature of matrix oil. Stirring affects the process yield by influencing the homogeneity
of the oil/glycol two-phase system. Ultrasounds can improve the process efficiency by making operating conditions less severe.
Selected article from the 6th European Meeting on Environmental Chemistry, University of Belgrade, Serbia and Montenegro organized
by Prof. Dr. Branimir Jovancicevic (). 相似文献
400.
Potential Habitat and Biodiversity Losses from Intensified Biodiesel Feedstock Production 总被引:3,自引:0,他引:3
LIAN PIN KOH 《Conservation biology》2007,21(5):1373-1375