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排序方式: 共有941条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2021,47(23):32710-32719
The formation of micro-cracks in Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode particles is an extremely important factor affecting the electrochemical characteristics after long-term cycling. Generally, cracks can be divided into intergranular crack and intracrystalline crack according to their positions. Coating has been confirmed as a highly effective strategy to relieve intergranular cracks. However, the intracrystalline cracks of primary-like particles have rarely been studied. In this work, ethoxy functional polysiloxane (EPS) was directly coated on the surface of original NCM811 by tetraethyl orthosilicate (TEOS) hydrolytic polycondensation method without any additives. Then, the microstructure, micromorphology, surface state and electrochemical properties were investigated in detail by XRD, SEM, TEM, CV and EIS. The results displayed that the micro-cracks of primary-like particles were effectively suppressed under appropriate EPS coating. Accordingly, excellent capacity retention of 95.6% (100 cycles, 1C) and rate performance (144.6 mA h/g, 5C) were obtained. These improved mechanical and electrochemical properties are considered to be related to the EPS stress buffer layer, suppressed oxygen vacancies, inhibited phase transition and reduced volume change. 相似文献
2.
Anand J. Puppala Pinit Ruttanaporamakul Surya Sarat Chandra Congress 《Geotextiles and Geomembranes》2019,47(3):295-305
This paper presents a research study on a bridge site located along US highway 67 over SH 174 in Cleburne, Texas, where bridge approach slabs have experienced more than 0.4 m (17 in.) of settlement within a span of 16 years after construction. Many treatment methods attempted to mitigate this problem had proven to be ineffective. As part of novel rehabilitation works, the top of existing fill soil on the embankment was replaced with lightweight expanded polystyrene (EPS) geofoam blocks to alleviate the approach slab settlements. This paper describes initial design and construction details of the rehabilitation works performed on the embankment system along with a focus on the early performance details. Field monitoring studies were conducted for almost three years to study the bump/settlements under the EPS geofoam embankment system. Short term measured settlement data was analyzed with hyperbolic model to predict the long term settlements. Numerical finite element studies attempted in this study showed that settlements could be reasonably predicted by modeling these geofoam embankments. Based on the monitoring and modeling studies, the effectiveness of utilizing EPS geofoam as an embankment fill material was addressed to mitigate the differential settlements under a bridge approach slab. 相似文献
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Zhao Chen Xiaojing Zhang Yongpeng Ma Shilei Li Qi Pang Haoxu Wang Gaochao Sun 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2020,95(12):3252-3260
The appearance of heavy metals in wastewater brings a major burden to wastewater treatment plants, due to the high toxicity to microorganisms. Several commonly used heavy metals, including Zn(II), Cd(II), Hg(II), and Pb(II) were adopted to clear the individual and joint toxicity to the completely autotrophic nitrogen removal over nitrite (CANON) process in six sequencing batch reactors. The obtained results suggested that the nitrogen removal performances were transiently inhibited, but rapidly recovered. The restoration period under the stress of Hg(II) and Pb(II) was shorter than that under Zn(II), Cd(II), and the joint heavy metals. During the long-term exposure, Cd(II) in 1mg L−1 slightly inhibited the nitrogen removal, while Zn(II), Hg(II), Pb(II), and mixture showed a negligible impact on CANON process. The defense of extracellular polymeric substances (EPS), the good adaptability of functional bacteria, and the inducement of resistant genera by heavy metals all contributed to the robustness and stability of CANON process. Therefore, it is feasible to treat nitrogenous wastewater containing low heavy metals using CANON process. © 2020 Society of Chemical Industry 相似文献
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Alexandru I. Petrisor Sandra Szyjka Tomohiro Kawaguchi Pieter T. Visscher Robert Sean Norman Alan W. Decho 《International journal of molecular sciences》2014,15(1):850-877
Microspatial arrangements of sulfate-reducing microorganisms (SRM) in surface microbial mats (~1.5 mm) forming open marine stromatolites were investigated. Previous research revealed three different mat types associated with these stromatolites, each with a unique petrographic signature. Here we focused on comparing “non-lithifying” (Type-1) and “lithifying” (Type-2) mats. Our results revealed three major trends: (1) Molecular typing using the dsrA probe revealed a shift in the SRM community composition between Type-1 and Type-2 mats. Fluorescence in-situ hybridization (FISH) coupled to confocal scanning-laser microscopy (CSLM)-based image analyses, and 35SO4
2−-silver foil patterns showed that SRM were present in surfaces of both mat types, but in significantly (p < 0.05) higher abundances in Type-2 mats. Over 85% of SRM cells in the top 0.5 mm of Type-2 mats were contained in a dense 130 μm thick horizontal layer comprised of clusters of varying sizes; (2) Microspatial mapping revealed that locations of SRM and CaCO3 precipitation were significantly correlated (p < 0.05); (3) Extracts from Type-2 mats contained acylhomoserine-lactones (C4-, C6-, oxo-C6 C7-, C8-, C10-, C12-, C14-AHLs) involved in cell-cell communication. Similar AHLs were produced by SRM mat-isolates. These trends suggest that development of a microspatially-organized SRM community is closely-associated with the hallmark transition of stromatolite surface mats from a non-lithifying to a lithifying state. 相似文献
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上海沪青平高速公路施工期间,发生桥台横向位移和引道填土滑坡的情况。为避免位移进一步扩大,确保桥 梁结构安全和引道结构稳定,在经过多方案比选后,采用EPS材料进行填筑,取得了满意的效果。虽然EPS这种轻型 高分子聚合材料因造价偏高而未能广泛使用,但用于特殊情况下的补救措施还是合理可行的。 相似文献
9.
EPS材料是一种应用广泛、实用性强的建筑热工节能材料。用于建筑的外墙外保温结构,具有良好的热工性能、节能与环保等优点。针对实际工程中常出现的保温层脱落、饰面层开裂及外观效果欠佳等问题,提出在EPS材料外墙外保温工程施工中,除加强施工技术的改进外,还必须注意选材的质量和主要材料间的相容性,才能保证工程质量,收到预期的技术和经济效益。 相似文献
10.
Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge 总被引:28,自引:0,他引:28
Laboratory experiments on the activated sludge (AS) process were carried out to investigate the influence of microbial extracellular polymeric substances (EPS), including loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS), on biomass flocculation, sludge settlement and dewaterability. The heat EPS extraction method was modified to include a mild step and a harsh step for extracting the LB-EPS and TB-EPS, respectively, from the sludge suspension. Six lab-scale AS reactors were used to grow AS with different carbon sources of glucose and sodium acetate, and different sludge retention times (SRTs) of 5, 10 and 20 days. The variation in the bioreactor condition produced sludge with different abundances of EPS and different flocculation and separation characteristics. The sludge that was fed on glucose had more EPS than the sludge that was fed on acetate. For any of the feeding substrates, the sludge had a nearly consistent TB-EPS value regardless of the SRT, and an LB-EPS content that decreased with the SRT. The acetate-fed sludge performed better than the glucose-fed sludge in terms of bioflocculation, sludge sedimentation and compression, and sludge dewaterability. The sludge flocculation and separation improved considerably as the SRT lengthened. The results demonstrate that the LB-EPS had a negative effect on bioflocculation and sludge-water separation. The parameters for the performance of sludge-water separation were much more closely correlated with the amount of LB-EPS than with the amount of TB-EPS. It is argued that although EPS is essential to sludge floc formation, excessive EPS in the form of LB-EPS could weaken cell attachment and the floc structure, resulting in poor bioflocculation, greater cell erosion and retarded sludge-water separation. 相似文献