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1.
In the chemical industry large amounts of saline wastewater occur. Its disposal into rivers is a considerable burden to the ecosystem. To strive for a circular economy and enable a viable raw material recycling, energy-efficient concentration processes are requisite. High-pressure reverse osmosis meets this criterion, but its industrial application demands suitable membrane elements that withstand the exceptional operation conditions and provide sufficient performance. Hence, new requirements regarding the design of spiral-wound elements arise. To identify those, specific performance-limiting effects need a better understanding.  相似文献   
2.
The compulsion to use bioplastics has increased significantly today. One of the important aspects of plastics is their recyclability. Therefore, the important question of this research is that although bio-based compounds containing starch are sensitive to thermal-mechanical recycling processes, are such products thermally recyclable? To answer the question, polypropylene (PP)/thermoplastic starch (TPS) compound granules were extruded up to five times, and in the other part, single-extruded granules were blended at different ratios with virgin granules by extrusion. In order to characterize these samples, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, rotational disc rheometry, tensile properties, and appearance evaluation were used. The results showed that it is possible to recycle PP/TPS granules up to four times repetition of the extrusion operation and the fifth repetition also showed slight changes. There was also a blend of single-extruded granules with virgin material up to a 50:50% composition without significant variation.  相似文献   
3.
ABSTRACT

Studies have been performed with the purpose of determining the optimal solvent composition of a Chalmers grouped actinide extraction (CHALMEX) solvent for the selective co-extraction of transuranic elements in a novel Grouped ActiNide EXtraction (GANEX) process. The solvent is composed of 6,6’-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-[1,2,4]-triazin-3-yl)-[2,2’]-bipyridine (CyMe4-BTBP) and tri-n-butyl phosphate (TBP) in phenyl trifluoromethyl sulfone (FS-13). The performance of the system has been shown to significantly depend on the ratios of the two extracting agents and the diluent to one another. Furthermore, the performance of the determined optimal solvent (10 mM CyMe4-BTBP in 30% v/v TBP and 70% v/v FS-13) on various simulated PUREX raffinate solutions was tested. It was found that the solvent extracts all transuranic elements with high efficiency and good selectivity with regard to most other elements (fission products/activation products) present in the simulated PUREX raffinate solutions. Moreover, the solvent was found to extract a significant amount of acid. Palladium, silver, and cadmium were co-extracted along with the TRU-radionuclides, which has also been observed in other similar CHALMEX systems. The extraction of plutonium and uranium was preserved for all tested simulated PUREX raffinate solutions compared to experiments using trace amounts.  相似文献   
4.
蔡毅  田晖  谢淼雪 《中国塑料》2021,35(8):77-83
塑料是家用电器中广泛使用的原材料,如何高效高值地回收利用废旧家用电器塑料是至关重要的问题。各种塑料依据其性能优势在家电产品中得到广泛应用,并呈现轻量、健康和环保的发展趋势。通过对我国废塑料再生行业的政策和标准进行梳理和分析,综述了废塑料回收利用现状。最后,提出了发展建议:在生产者责任延伸制度的推动下,废旧家用电器塑料行业可采用智能化高效分选设备与复合处理工艺提升资源化利用价值;开展再生塑料行业的相关标准化工作;构建与完善再生材料的应用市场;加强生态设计提升原生塑料的可再生利用性。  相似文献   
5.
干法后处理技术是我国核燃料循环体系的重要发展方向,其中有发展前景的熔盐电解法在工业化过程中需要对元素进行准确地监测以保障安全运行。传统离线检测方法程序复杂、数据分析延迟,而在线监测方法因可以获得实时数据而备受瞩目。本文对近几年国内外熔盐电解法中不同元素的在线监测技术进行了总结,重点调研分析了电化学法中的循环伏安法、安培法、脉冲法以及光谱法中的荧光光谱法和紫外光谱法在各种元素的在线监测中的原理、特点和应用前景,以期对熔盐电解中在线监测技术的研发和实际应用提供理论支撑和技术参考。  相似文献   
6.
The influence of two peroxides (peroxydicarbonate/dilauroyl peroxide) with various concentrations (10–200 mmol/kg PP) and their effective opportunity to introduce long chain branched (LCB) were investigated. The dependence of a single and double extrusion step and the changes of the properties were studied. Experiments were carried out in a single screw extruder at 180°C for the first extrusion step (modification) and at 240°C for the second extrusion step (processing simulation). Melt flow rate and dynamic rheological properties were studied at a measuring temperature of 230°C. For the definitive determination of long chain branched polypropylene (LCB-PP) served the extensional rheology measurements. The mechanical properties were examined via tensile test and impact tensile test. Summarized, LCB (melt strength) could be observed via extensional rheology for all modified specimens and the mechanical properties were maintained or even improved for the modified samples. Particularly, samples containing dilauroyl peroxide display excellent mechanical properties in this study.  相似文献   
7.
彭浩  朱军  王斌  党晓娥  叶金地 《矿冶工程》2021,41(5):99-102
提出了一种以FeO-SiO2-Al2O3-CaO渣体系为基础的废旧电路板还原熔炼工艺,从减少渣中金属损失及控制性能角度,对渣成分及结构进行调控,研究了熔剂添加量、熔炼时间、熔炼温度、炉渣组成成分对金属回收率的影响。结果表明,在熔剂添加量为原料质量30%、熔炼温度1 450 ℃、熔炼时间75 min、FeO/SiO2比为1、渣中CaO含量8%条件下,废旧电路板中Cu、Sn回收率分别为91.98%、86.30%,贵金属Au、Ag、Pt在合金相中含量分别可达67.41 g/t、1 020.74 g/t、54.75 g/t。以该渣系为基础还原熔炼废旧电路板的工艺是可行的。  相似文献   
8.
概述了我国废旧塑料再生利用现状及应用领域,通过大数据回归分析建立了废旧塑料利用率的算法模型,测算我国2009—2019年的废旧塑料利用率。2009—2014年,废旧塑料利用率从12.0%升至16.0%,2015—2019年略微下降。2009—2015年,塑料回收利用量持续增长,2016年,回收利用量有所下降,2017—2018年增长较快,2019年较2018年有小幅增长,从2018年的9.16 Mt增加到2019年的9.45 Mt。塑料再生资源比例系数对计算结果的影响幅度最大,在-2.65%~2.51%波动。塑料再生资源比例系数的不确定性影响由大到小依次为聚乙烯、聚氯乙烯、聚丙烯、聚苯乙烯、丙烯腈-丁二烯-苯乙烯共聚物。  相似文献   
9.
Understanding energy transport in metal halide perovskites is essential to effectively guide further optimization of materials and device designs. However, difficulties to disentangle charge carrier diffusion, photon recycling, and photon transport have led to contradicting reports and uncertainty regarding which mechanism dominates. In this study, monocrystalline CsPbBr3 nanowires serve as 1D model systems to help unravel the respective contribution of energy transport processes in metal-halide perovskites. Spatially, temporally, and spectrally resolved photoluminescence (PL) microscopy reveals characteristic signatures of each transport mechanism from which a robust model describing the PL signal accounting for carrier diffusion, photon propagation, and photon recycling is developed. For the investigated CsPbBr3 nanowires, an ambipolar carrier mobility of μ = 35 cm2 V−1 s−1 is determined, and is found that charge carrier diffusion dominates the energy transport process over photon recycling. Moreover, the general applicability of the developed model is demonstrated on different perovskite compounds by applying it to data provided in previous related reports, from which clarity is gained as to why conflicting reports exist. These findings, therefore, serve as a useful tool to assist future studies aimed at characterizing energy transport mechanisms in semiconductor nanowires using PL.  相似文献   
10.
学术英文写作是当今电子信息专业研究生必修的一门课程。然而传统的以教师为中心的灌输式教学已不能跟上网络迅猛发展的趋势,尤其是当疫情来临的特殊形势下。此外,现有的学术英文写作教学研究仅提供宏观的设计,缺乏具体的实际可操作性。为此,本文以引言写作逻辑为教学模块案例,探索了如何充分利用网络资源的优势,开展以学生为中心的课前课中课下有机融合的灵活的教学设计。所探索的引言写作技巧和详实的教学设计,为模块化网络教学提供一个切实可行的参考方案。  相似文献   
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