Harbin Institute of Technology

About: Harbin Institute of Technology is a education organization based out in Harbin, China. It is known for research contribution in the topics: Microstructure & Control theory. The organization has 88259 authors who have published 109297 publications receiving 1603393 citations. The organization is also known as: HIT.

Effects of Mn, Ti and V on the microstructure and properties of AlCrFeCoNiCu high entropy alloy

Abstract: Mn, Ti and V were added in an equal-molar ratio to the AlCrFeCoNiCu alloy and the effects of these added elements on microstructure and properties of AlCrFeCoNiCu high entropy alloy were studied. The results indicate that the AlCrFeCoNiCuMn alloy shows almost the same microstructure as in AlCrFeCoNiCu alloy except for a long-strip Cr-enriched phase. The additions of Ti change the AlCrFeCoNiCu alloy from a dendrite structure to eutectic-cell one. Hence two phases in the eutectic cells are detected as one Al, Ti, Co, Ni enriched phase and another Cr, Fe enriched phase. V added alloy is also a dendrite structure, but V additions change the morphology of dendritic area from modulated plates to ellipsoidal particles. The addition of V into the AlCrFeCoNiCu alloy shows the best strengthening effect and the lowest decrease in the ultimate strain in our experiments.

Towards certain fixes with editing rules and master data

Abstract: A variety of integrity constraints have been studied for data cleaning. While these constraints can detect the presence of errors, they fall short of guiding us to correct the errors. Indeed, data repairing based on these constraints may not find certain fixes that are absolutely correct, and worse, may introduce new errors when repairing the data. We propose a method for finding certain fixes, based on master data, a notion of certain regions, and a class of editing rules. A certain region is a set of attributes that are assured correct by the users. Given a certain region and master data, editing rules tell us what attributes to fix and how to update them. We show how the method can be used in data monitoring and enrichment. We develop techniques for reasoning about editing rules, to decide whether they lead to a unique fix and whether they are able to fix all the attributes in a tuple, relative to master data and a certain region. We also provide an algorithm to identify minimal certain regions, such that a certain fix is warranted by editing rules and master data as long as one of the regions is correct. We experimentally verify the effectiveness and scalability of the algorithm.

Magnetic polyaniline nanocomposites toward toxic hexavalent chromium removal

Abstract: The removal of toxic hexavalent chromium (Cr(VI)) from polluted water by magnetic polyaniline (PANI) polymer nanocomposites (PNCs) was investigated. The PNCs were synthesized using a facile surface initiated polymerization (SIP) method and demonstrated unique capability to remove Cr(VI) from polluted solutions with a wide pH range. Complete Cr(VI) removal from a 20.0 mL neutral solution with an initial Cr(VI) concentration of 1.0–3.0 mg L−1 was observed after a 5 min treatment period with a PNC load of 10 mg. The PNC dose of 0.6 g L−1 was found to be sufficient for complete Cr(VI) removal from 20.0 mL of 9.0 mg L−1 Cr(VI) solution. The saturation magnetization was observed to have no obvious decrease after treatment with Cr(VI) solution, and these PNCs could be easily recovered using a permanent magnet and recycled. The Cr(VI) removal kinetics were determined to follow pseudo-first-order behavior with calculated room temperature pseudo-first-order rate constants of 0.185, 0.095 and 0.156 min−1 for the solutions with pH values of 1.0, 7.0 and 11.0, respectively. The Cr(VI) removal mechanism was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and energy-filter transmission electron microscopy (EFTEM). The results showed that PANI was partially oxidized after treatment with Cr(VI) solution, with Cr(VI) being reduced to Cr(III). The EFTEM observation indicated that the adsorbed Cr(III) had penetrated into the interior of the PNCs instead of simply adsorbing on the PNC surface. This synthesized material was found to be easily regenerated by 1.0 mol L−1p-toluene sulfonic acid (PTSA) or 1.0 mol L−1 hydrochloric acid (HCl) and efficiently reused for further Cr(VI) removal.