Exploring the environmental properties and resource utilization of construction waste in Beijing-Tianjin-Hebei region.

Beijing-Tianjin-Hebei region is a capital economic circle for the future. Promoting the coordinated development of its population, economy, resources and environment is a major national strategy. And as towns and cities continue to expand, the volume of construction waste is gradually expanding, posing a major challenge to the sustainable development of the construction industry. In order to solve this problem, this paper used portable X-ray fluorescence spectrometry to realize the on-site rapid monitoring of heavy metals in construction waste, and the correlation analysis result was R2 = 0.9908. The visualization of enrichment factor evaluation results was realized through ArcGIS. The Beijing-Tianjin-Hebei region is mainly polluted by heavy metal elements Cr, Zn, Pb and Hg, showing regional pollution characteristics, and the results of mercury morphology analysis show that all are inorganic mercury pollution, and methylmercury is not detected, and the cause can be traced to heavy industrial production in Tangshan City, which is consistent with industrial ecology. The results of leaching toxicity and cation anion analysis showed that the construction waste in Beijing-Tianjin-Hebei region had environmental risks to the surrounding surface water and groundwater. The resource treatment and disposal path were determined by means of XRD, ternary phase diagram and oxide composition analysis to avoid secondary pollution. This study explores the environmental properties and resource utilization pathways of construction waste in the Beijing-Tianjin-Hebei region, laying the foundation for research work on construction waste in the development of national urban agglomerations, effectively solving regional environmental pollution problems and promoting the sustainable development of the construction industry.

Interface engineering of semiconductor/dielectric heterojunctions toward functional organic thin-film transistors.

Interface modification is an effective and promising route for developing functional organic field-effect transistors (OFETs). In this context, however, researchers have not created a reliable method of functionalizing the interfaces existing in OFETs, although this has been crucial for the technological development of high-performance CMOS circuits. Here, we demonstrate a novel approach that enables us to reversibly photocontrol the carrier density at the interface by using photochromic spiropyran (SP) self-assembled monolayers (SAMs) sandwiched between active semiconductors and gate insulators. Reversible changes in dipole moment of SPs in SAMs triggered by lights with different wavelengths produce two distinct built-in electric fields on the OFET that can modulate the channel conductance and consequently threshold voltage values, thus leading to a low-cost noninvasive memory device. This concept of interface functionalization offers attractive new prospects for the development of organic electronic devices with tailored electronic and other properties.