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51.
以多壁碳纳米管(MWCNTs)、羟基碳纳米管(MWCNTs-OH)、羧基碳纳米管(MWCNTsCOOH)为催化剂载体,采用等体积浸渍法制备负载型Bi基催化剂,在固定床反应器中评价催化剂在乙炔氢氯化反应中的性能。结果表明,以MWCNTs-OH为载体的Bi基催化剂催化性能最优,乙炔转化率最高52%。BET、FT-IR、XRD、XPS、EDS、TG、TEM和H_2-TPR表征表明,碳纳米管表面基团,尤其是羟基,可以提高活性组分的分散度、抑制催化剂表面积炭生成和减少Bi物种流失。 相似文献
52.
Xingguang Chen Beibei Chu Huiting Xi Junjun Xu Lizhi Lai Huifeng Peng Danwen Deng Ganhui Huang 《Journal of dairy science》2018,101(11):9647-9658
Chloride ion concentration in milk was determined by pulsed amperometric detection in a flow injection system. Results showed that the Au electrode lost 3 electrons at 1.10 V and formed chloroaurate ions (AuCl4?) by combining with chloride ions, after which AuCl4? was partly reduced to Au at 0.6 V. Based on the electrochemical process, a triple waveform with detection potential of 1.15 V, detection time of 150 ms, oxidation potential of 1.4 V, oxidation time of 550 ms, reduction potential of 0 V, and reduction time of 400 ms was applied to the Au electrode for detecting chloride ion concentration in milk. The approach is rapid and automatic and features a detection limit of 0.005 g/L. The relative standard deviation obtained by 60 repetitive injections reached 1.48% at 2 g/L of NaCl. The method developed using the Au electrode without modification was used to analyze the chloride ion concentration in raw milk without preprocessing. The method showed good agreement with potentiometric titration. 相似文献
53.
Marieke M. Hoog Antink Lisa Röpke Julia Bartels Christian Soltmann Andreas Kunzmann Kurosch Rezwan Stephen Kroll 《Ceramics International》2018,44(14):16561-16571
The growing demand for stony corals as ornamental aquarium animals requires defined aquacultural breeding strategies. For the sexual propagation of corals, material substrates are needed, that attract larvae and support their settlement and development. In this study, five types of highly porous ceramic materials were developed following the example of coral skeleton. The applicability of these settlement substrates was tested using larvae of the stony coral Pocillopora damicornis. Partial sintering of pressed clay pellets, freeze casting of clay and alumina-mullite based slurries and direct foaming of high alkane phase emulsified suspensions (HAPES) using alumina were employed. By the addition of mm-sized spherical polystyrene beads as sacrificial templates during freeze casting (alumina-mullite), superficial pores in the size of the larvae were created. The inorganic substrates featured open porosities between 35% (pressed clay) and 83% (foamed alumina), pore sizes ranging from nm to mm-scale and pore morphologies dominated by interparticle porosity (pressed), lamellar pores (freeze casting) and cellular pore types (direct foaming). The ceramic substrates were incubated in artificial sea water for 3 months to induce necessary biofilm formation and algae growth. Afterwards, individual substrates were exposed to 5 coral larvae, and their settlement behavior was monitored over 14 days. At the end of this period, all ceramic materials were successfully accepted as settlement substrates, with a mean settlement rate of 46.2%, and no significant differences between the substrate types. On samples with large surface superficial pores, a significantly reduced survival of settled larvae (79%) compared to the other porous materials (93–98%) was determined, suggesting a non-ideal surface topography. While alumina foam samples (HAPES) exhibit the most promising results in terms of settlement and survival of larvae, clay-based substrates provide a more economic solution for the sexual propagation of corals in aquaculture. 相似文献
54.
The micellization behavior of amphiphiles is a well-analyzed physicochemical phenomenon, which can be easily influenced by various parameters such as pressure, temperature, and the presence of different additives. Inorganic salts are able to affect the thermodynamic and surface properties of amphiphiles significantly. The effect of a series of salts as additives namely lithium chloride (LiCl), potassium chloride (KCl), sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) on interfacial chemical characteristics of the surface-active ionic liquid (SAIL) 1-dodecyl-3-methylimidazolium chloride [C12mim][Cl] in aqueous solution were examined through conductance, surface tension, fluorescence, 1H NMR, and dynamic light scattering measurements. The interfacial and thermodynamic parameters of all investigated SAIL-salt systems were evaluated from surface tension and conductance measurements, respectively. A detailed analysis of the microenvironment of the micelles and the size of the micelles was done using 1H NMR and dynamic light scattering measurements. 相似文献
55.
56.
Paulo Carmo Ana M. Ribeiro Alírio E. Rodrigues Alexandre Ferreira 《American Institute of Chemical Engineers》2020,66(5):e16899
This work aims at developing an efficient and feasible adsorption-based separation process for the separation of vinyl chloride and nitrogen, on activated carbon, by employing a multitubular packed bed geometry, with adsorbent material inside the tubes. Using this geometry, a 2-dimensional mathematical model of a temperature pressure swing adsorption process was used to developed a 6-step three multitubular adsorbers system capable of separating and purifying an industrial scale gas stream of a 40:60% (v/v) vinyl chloride/nitrogen mixture into a 95% (v/v) vinyl chloride stream and a nitrogen stream with a vinyl chloride limit concentration of 8 ppm (w/w). The process reported energy consumption of 4.88 × 106 J/kgVCM and recovery capacity of 24.35 kgVCM/(m3unit h). The multitubular geometry enabled the use of lower adsorbent loads, shorter cycle times, and lower regeneration temperatures. An equivalent 1-dimensional model has also shown to satisfactorily estimate the performance of the current equipment. 相似文献
57.
In the present study, a renewable resource-based plasticizer was synthesized by the lipase-catalyzed esterification reaction of furfuryl alcohol (FA) and castor oil fatty acid (COFA). The resultant ester (FA-COFA ester) was used as secondary plasticizers to the polyvinyl chloride (PVC) films. The PVC films were formulated using the combination of a conventional plasticizer di-butyl phthalate (DBP) and FA-COFA ester as a secondary plasticizer at different concentrations. Films were characterized by X-ray diffraction analysis, scanning electron microscopy, thermal analysis, mechanical performance, and migration stability. A biodegradability study of the PVC films showed increased degradability with increasing concentration of the FA-COFA ester in the PVC film. The study showed that ester of FA and COFA could be a substitute of DBP by as much as 80% of the total plasticizer with improved elongation and tensile properties, and such a kind of sustainable resource-based PVC blend films could be used as a good packaging material with biodegradable property. 相似文献
58.
59.
Gabriel Reboux Steffi Rocchi Audrey Laboissire Habiba Ammari Martine Bochaton Guillaume Gardin Jean‐Marc Rame Laurence Millon 《Indoor air》2019,29(1):5-16
Different countries have tried to define guidelines to quantify what levels of fungi are considered as inappropriate for housing. This retrospective study analyzes indoor fungi by cultures of airborne samples from 1012 dwellings. Altogether, 908 patients suffering from rhinitis, conjunctivitis, and asthma were compared to 104 controls free of allergies. Portuguese decree law no 118/2013 (PDL118), ANSES (a French environmental and health agency) recommendations, and health regulations of Besançon University Hospital were applied to determine the rates of non‐conforming dwellings, which were respectively 55.2%, 5.2%, and 19%. Environmental microbiological results and medical data were compared. The whole number of colonies per cubic meter of air was correlated with asthma (P < 0.001) and rhinitis (P = 0.002). Sixty‐seven genera and species were detected in bedrooms. Asthma was correlated to Aspergillus versicolor (P = 0.004) and Cladosporium spp. (P = 0.02). Thresholds of 300 cfu/m3 for A. versicolor or 495 cfu/m3 for Cladosporium spp. are able to discriminate 90% of the asthmatic dwellings. We propose a new protocol to obtain an optimal cost for indoor fungi surveys, excluding surface analyses, and a new guideline to interpret the results based on >1000 cfu/m3 of whole colonies and/or above threshold levels for A. versicolor or Cladosporium spp. 相似文献
60.
经济发展与生态环境动态良性循环已经成为社会经济发展的重要议题。为实现长江经济带高质量发展,以2007—2018年长江经济带11个省市为样本,采用空间计量和面板门槛模型考察工业集聚与水环境污染之间的关系。研究表明:长江经济带各省市水环境污染具有显著的空间自相关性;长江经济带工业集聚水平和水环境污染表现出先降低后增强的“U”形变化特征,说明工业集聚水平对水环境污染的影响存在一个阈值;长江经济带工业集聚产生的规模效应和结构效应对水环境污染存在显著的双门槛效应,在不同的工业集聚水平下,规模效应和结构效应表现出不同的外部性特征;工业集聚产生的技术溢出效应对水环境污染的影响同样具有显著的双门槛作用;随着各地区工业集聚水平的提高,技术溢出效应对水环境污染的减排作用表现出先强后弱的趋势。 相似文献