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981.
通过专利对菌丝体进行了改性。所制备的改性菌丝体对重金属离子具有良好的吸附效果。结果表明 ,其对Ni2 + 的吸附容量 6 3.2mg/g (初始水溶液中Ni2 + 浓度为 2 0 0mg/L) ,是甲壳素吸附剂的 3.3倍 (19.1mg/g) ,与壳聚糖吸附剂相比吸附容量提高了 135 % ,与D75 1与南开 15 2相比吸附容量非常接近。用 0 .5 %— 0 .2 %的解吸剂便可以完全解吸 ,能够重复使用达 6次以上。本文还研究了改性菌丝体对Ni2 + 的吸附过程中重要的影响因素 ,结果发现 ,在微碱性 (pH =8— 9)条件下 ,改性菌丝体可以把初始浓度高达 80 0mg/L的Ni2 + 溶液一次性降低到 17mg/L ,为改性菌丝体在工业废水处理中的应用奠定了良好的基础。 相似文献
982.
Tan PV Fila MS Evans GJ Jervis RE 《Journal of the Air & Waste Management Association (1995)》2002,52(1):27-40
Primary sources of particulate matter (PM) were analyzed by suspending powdered samples into an aerosol laser ablation mass spectrometer (LAMS). PM sources studied included vehicle exhaust particulates, dust from a non-ferrous smelter, cement powder, incinerator fly ash, two coal fly ash samples, and two soils. Marker peaks signified certain PM source sectors: construction particles could be distinguished by abundant Ca and Ca compounds, fuel combustion was marked by elemental carbon clusters, and nonferrous industrial particles showed inorganic As, Cu, Pb, Zn, and SOx. In addition to the distinction between particles from these different source sectors, mass spectral results also showed that for a single source, different particle types existed, and among different sources within a sector, similar spectra were present. The aerosol LAMS results show the difficulty in differentiating among separate fly ash sources as well as among different soil samples. A particle class balance receptor model that measures the amount of specific particle types rather than the amount of a chemical component is suggested as a means of source apportionment when particle spectra with overlapping source possibilities occur. The assumptions and limitations of receptor modeling aerosol LAMS data are also described. In particular, methods need to be developed to account for the contribution of secondary sources. 相似文献
983.
本文系统研究了菌丝体 -甲壳素 (甲壳素 )作为水处理剂对去除水体中Ni2 + 离子时的吸附特性 ,结果表明 ,甲壳素作为水处理剂 ,在较大pH值变化范围内 ,对Ni2 + 离子与柠檬酸镍都有较高的吸附容量 ;甲壳素在吸附金属离子的同时 ,对H+ 有吸附作用 ,且H+ 是金属离子的竞争性抑制剂。将甲壳素与市售吸附树脂相比 ,其对阳离子 (Ni2 + )和络阴离子(柠檬酸镍Ni(cit) 2 -)的吸附特性类似于阳离子交换树脂。同时 ,甲壳素不会带来二次污染 ,是一种具有广泛应用前景的环保型工业水处理剂。 相似文献
984.
Chow JC Engelbrecht JP Freeman NC Hashim JH Jantunen M Michaud JP Saenz de Tejada S Watson JG Wei F Wilson WE Yasuno M Zhu T 《Chemosphere》2002,49(9):873-901
Determining human exposure to suspended particulate concentrations requires measurements that quantify different particle properties in microenvironments where people live, work, and play. Particle mass, size, and chemical composition are important exposure variables, and these are typically measured with time-integrated samples on filters that are later submitted to laboratory analyses. This requires substantial sample handling, quality assurance, and data reduction. Newer technologies are being developed that allow in-situ, time-resolved measurements for mass, carbon, sulfate, nitrate, particle size, and other variables. These are large measurement systems that are more suitable for fixed monitoring sites than for personal applications. Human exposure studies need to be designed to accomplish specific objectives rather than to serve too many purposes. Resources need to be divided among study design, field sampling, laboratory analysis, quality assurance, data management, and data analysis phases. Many exposure projects allocated too little to the non-measurement activities. 相似文献
985.
Summary. Geckos consumed immature Bactrocera carambolae males readily, but their consumption was reduced significantly when offered sexually mature males. They showed a similar
aversion for sexually mature males previously fed with methyl eugenol. When male flies at different ages were offered to starved
geckos, geckos’ consumption showed an age-related anti-feeding effect, which was concomitant with the production trend of
6-oxo-1-nonanol, a major endogenous component synthesized in the male rectal gland. The production of 6-oxo-1-nonanol was
also age-related and corresponded with sexual maturity as reported previously. Topical application of the authentic chemical
of 6-oxo-1-nonanol onto the thorax of female fruit flies, at the amount normally detected in the rectal gland of a sexually
mature male, had the same deterrent effect against geckos. 相似文献
986.
Summary. Males of dacine tephritids, Bactrocera carambolae and B. dorsalis are strongly attracted to, and compulsively feed on methyl eugenol (ME), a potent attractant for many Bactrocera species. While ME was shown to be biotransformed into phenylpropanoids, 2-allyl-4,5-dimethoxyphenol and (E)-coniferyl alcohol, and temporarily stored in the rectal gland of male B. dorsalis prior to release during courtship at dusk, B. carambolae male produces only the latter compound along with its de novo synthesized pheromone components. Both species were also shown to have different age-related response, sensitivity and consumption
levels of ME. Here, we monitored and compared temporal changes in the accumulation profiles of these phenylpropanoids by the
two sibling species, with male rectal glands being individually excised at different time intervals from 15 minutes to 20
days after initial ME feeding and analysed quantitatively. Results are discussed in light of plant-fruit fly co-evolution
relationship. 相似文献
987.
中小城镇环境规划中循环经济理念的拓展 总被引:8,自引:0,他引:8
我国小城镇环境规划作为社会经济发展计划的有机组成部分,是促进城镇的环境管理和可持续发展的重要手段。循环经济是生态型经济,在小城镇环境规划中引入循环经济理念并对其指标和内容进行拓展,目的是实现资源的高效利用和不断循环,使城镇经济发展更适应环境保护和生态循环的需要,是未来重要的发展趋势之一。 相似文献
988.
美国洪泛平原管理的新方向 总被引:1,自引:0,他引:1
根据美国联邦跨机构洪泛平原管理审查委员会对密西酉比河1993年特大洪水的调查分析以及对美国现行洪泛平原管理方式、水土资源规划的原则与准则等的评价,简要介绍现有管理方式存在的问题与发展方向,为我国从事洪泛区规划与管理提供参考信息. 相似文献
989.
采用低压水射流辅助聚晶金刚石刀具车削花岗岩,采集不同切削条件下切削力的数据,分析了在水射流辅助下刀具进给量、切削深度、切削速度、水射流压力、喷射距离对切削力的影响。结果表明,在实验压力范围内,切削过程中,水射流使岩石受到冲蚀,并使微裂纹扩展,有利于岩石的切削。切削力随着水射流压力的增大而减少。 相似文献
990.
就大气环境影响评价中理解和执行GB/T13201-91、GB3095-82的几个问题提出了看法和建议。 相似文献