Beijing University of Technology

About: Beijing University of Technology is a education organization based out in Beijing, Beijing, China. It is known for research contribution in the topics: Microstructure & Laser. The organization has 31929 authors who have published 31987 publications receiving 352112 citations. The organization is also known as: Běijīng Gōngyè Dàxué & Beijing Polytechnic University.

Ceramic tubular MOF hybrid membrane fabricated through in situ layer-by-layer self-assembly for nanofiltration

Abstract: Nanofiltration has been playing an important role in water purification, in which the developments of novel membrane materials and modules are among significant. Herein, a metal-organic framework (MOFs) hybrid membrane, ZIF-8/PSS was fabricated on a tubular alumina substrate through a layer-by-layer self-assembly technique. ZIF-8 particles in situ grow into PSS layers to improve their compatibility and dispersion, thereby getting high quality membrane, which was loaded into a steel tubular module for nano-filtrating dyes from water. Under optimized conditions, it shows outstanding nanofiltration properties toward methyl blue, with the flux of 210 Lm−2 h−1 MPa−1 and the rejection of 98.6%. Furthermore, the good pressure resistance ability and running stability of the membrane were revealed, which can be attributed to use the ceramic substrate and the inherent stability of ZIF-8. This work thus illustrates a simple approach for fabricating MOFs hybrid membranes on tubular ceramic substrates, having great potential for industrial applications. © 2015 American Institute of Chemical Engineers AIChE J, 62: 538–546, 2016

The stability and profitability of the informal WEEE collector in developing countries: A case study of China

Abstract: Different attitudes and practices toward WEEE recovery and recycling are found in developed and developing countries. As the largest developing country in the world, China's WEEE is widely regarded as a valuable product, and the resources contained in it offer potential profit for informal collectors. Unlike the formal collectors, who are supported by the government, informal collectors can only rely on themselves. However, formal and informal collectors often comfortably coexist in developing countries and there are even cases of informal collectors dominating the market. Obsolete television (OTV) in Beijing is employed as a case study. Questionnaire survey and multi-agent cost-benefit analysis are used to analyze the stability and profitability of the informal collector. The results show the following: (1) The factors of price, convenience and canonicity can affect consumers’ motivations when selecting a collector, with price and convenience having the strongest impact. And informal collectors can better meet consumers’ demands. (2) Stable cooperation within tier two collectors is formed by profit-driven individuals. The secondhand market can expand the profits of the first-tier collectors, while the remaining OTV, which cannot be reused, is delivered to the middleman, ensuring that the first-tier collectors are not menaced from the “rear”. (3) The informal backyard recycler expands the profit of the middleman. Meanwhile, the WEEE processing fund is mostly shared by collectors and intensifies the confusion of the recovery market. We then create a new fund system to improve the regulation of OTV recovery. To make formal collections work, we suggest that the government charges an extra 40 Yuan fund when consumers buy new TVs and distribute it to formal collectors in order to exclude the informal collectors.

Abundance and diversity based on amoA genes of ammonia-oxidizing archaea and bacteria in ten wastewater treatment systems

Abstract: The abundance and diversity of amoA genes of ammonia-oxidizing archaea (AOA) and bacteria (AOB) were investigated in ten wastewater treatment systems (WTSs) by polymerase chain reaction (PCR), cloning, sequencing, and quantitative real-time PCR (qPCR). The ten WTSs included four full-scale municipal WTSs, three full-scale industrial WTSs, and three lab-scale WTSs. AOB were present in all the WTSs, whereas AOA were detected in nine WTSs. QPCR data showed that AOB amoA genes (4.625 × 104–9.99 × 109 copies g−1 sludge) outnumbered AOA amoA genes (

Crystalline Grain Interior Configuration Affects Lithium Migration Kinetics in Li-Rich Layered Oxide

Abstract: The electrode kinetics of Li-ion batteries, which are important for battery utilization in electric vehicles, are affected by the grain size, crystal orientation, and surface structure of electrode materials. However, the kinetic influences of the grain interior structure and element segregation are poorly understood, especially for Li-rich layered oxides with complex crystalline structures and unclear electrochemical phenomena. In this work, cross-sectional thin transmission electron microscopy specimens are “anatomized” from pristine Li1.2Mn0.567Ni0.167Co0.067O2 powders using a new argon ion slicer technique. Utilizing advanced microscopy techniques, the interior configuration of a single grain, multiple monocrystal-like domains, and nickel-segregated domain boundaries are clearly revealed; furthermore, a randomly distributed atomic-resolution Li2MnO3-like with an intergrown LiTMO2 (TM = transitional metals) “twin domain” is demonstrated to exist in each domain. Further theoretical calculations based on...