Microstructure, phase transformation, electrochemistry, X-ray visibility and mechanical properties

Funding Information: Supporting for the Chinese Civil Aviation Administration (No. U1933129 ), Key Program of the Natural Science Foundation of Tianjin (No. 19JCZDJC39000 ). JPO acknowledges the Fundação para a Ciência e Tecnologia ( FCT ) for its support via the project UID/00667/2020 (UNIDEMI). JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. Publisher Copyright: © 2022 The AuthorsWire and arc additive manufacturing (WAAM) technology was used for the fabrication of NiTiTa (2.5 at. % Ta) shape memory alloys (SMAs) for the first time, using commercialy available NiTi wire and Ta foil as the feedstock materials. The addition of Ta significantly increased the phase transformation temperatures, leading to a room-temperature microstructure composed of both B19′ martensite and B2 austenite, and (Ti,Ta)2Ni precipitates distributed at the grain boundaries. Compared with the WAAM fabricated NiTi counterpart, the corrosion potential (Ecorr) of the NiTiTa material increased from − 0.55 to − 0.44 V, while the corrosion current density (Icorr) decreased from 1.90 × 10−6 to 4.2 × 10−7 A/cm2. The X-ray brightness increased from 19.6 to 56.4 %. These results indicate that the addition of Ta can enhance the corrosion resistance and X-ray visibility of NiTiTa parts. Furthermore, the WAAM fabricated NiTiTa material was able to retain a stable superelastic response under 10 loading-unloading cycles, highlighting the great potential application value in the biomedical field. Our work provides an innovative method for additively manufacturing NiTi-based multi-component SMAs through WAAM.publishersversionpublishe

Synthesis of 2D hollow hematite microplatelets with tuneable porosity and their comparative photocatalytic activities

State Key Development Program for Basic Research of China [2007CB935603]; National Natural Science Foundation of China [51372212]alpha-Fe2O3 2D hollow microplatelets were synthesized by a facile one-pot template-free solvothermal method. The effect of synthetic parameters on the morphology and structure of the product was systematically studied. And the possible formation mechanism was proposed. Interestingly, by simply varying the concentration of NH4F, alpha-Fe2O3 hollow microstructures with similar platelet-like shapes but different porosities can be readily obtained. Their comparative photocatalytic activities were also investigated

Hematite concave nanocubes and their superior catalytic activity for low temperature CO oxidation

Hematite (α-Fe2O3) concave nanocubes bound by high-index {1344} and {1238} facets were synthesized and their catalytic activity for CO oxidation were also investigated. ? 2014 the Partner Organisations

Fabrication of Au/Pd alloy nanoparticle/Pichia pastoris composites: a microorganism-mediated approach

Fundamental Research Funds for Central Universities [2010121051]; NSFC projects [21106117, 21036004]Synthesis of metal nanoparticles (NPs) is in the limelight in modern nanotechnology. In this present study, bimetallic Au/Pd NP/Pichia pastoris composites were successfully fabricated through a one-pot microbial reduction of aqueous HAuCl4 and PdCl2 in the presence of H-2 as an electron donor. Interestingly, flower-like alloy Au/Pd NP/Pichia pastoris composites were obtained under the following conditions, NaCl concentration 0.9% (w/v), molar ratio of Au/Pd (1 : 2) and the time for pre-adsorption of Au(III) and Pd(II) ions 15 min, through fresh yeast reduction. The mapping results from scanning transmission electron microscopy (STEM) with a high-angle annular dark field detector confirmed that the Au/Pd NPs on the surface of the yeast were indeed alloy. Furthermore, the energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) measurements showed that the composition of the bimetallic NPs were consistent with the initial molar ratio of the precursors

Disruption of splicing-regulatory elements using CRISPR/Cas9 to rescue spinal muscular atrophy in human iPSCs and mice

We here report a genome-editing strategy to correct spinal muscular atrophy (SMA). Rather than directly targeting the pathogenic exonic mutations, our strategy employed Cas9 and guide-sgRNA for the targeted disruption of intronic splicing-regulatory elements. We disrupted intronic splicing silencers (ISSs, including ISS-N1 and ISS + 100) of survival motor neuron (SMN) 2, a key modifier gene of SMA, to enhance exon 7 inclusion and full-length SMN expression in SMA iPSCs. Survival of splicing-corrected iPSC-derived motor neurons was rescued with SMN restoration. Furthermore, co-injection of Cas9 mRNA from Streptococcus pyogenes (SpCas9) or Cas9 from Staphylococcus aureus (SaCas9) alongside their corresponding sgRNAs targeting ISS-N1 into zygotes rescued 56% and 100% of severe SMA transgenic mice (Smn , SMN2 ). The median survival of the resulting mice was extended to >400 days. Collectively, our study provides proof-of-principle for a new strategy to therapeutically intervene in SMA and other RNA-splicing-related diseases. -/- tg/

Study on the technology of thermal cracking of paraffin to alpha olefins

Alpha olefins are mainly produced from paraffin cracking in China, but their quality is not good because of bad quality of cracking feed and outdated technology. The technology of paraffin once-through cracking, paraffin recycle cracking of removing the heavy fraction after wax vaporizing and that of removing the heavy fraction before wax vaporizing were investigated in this paper. It was found that the technology of paraffin recycle cracking of removing the heavy fraction before wax vaporizing is new and better under the same operating conditions. Using hard paraffin (mp 54-56 degrees C) as feed, the high-quality alpha olefins products (C(5)-C(21)) containing more than 97 wt% of olefins and more than 88 wt% of alpha olefins are produced under optimum process conditions, which are a steam to paraffin ratio of 15 wt%, process temperature of 600 degrees C, low hydrocarbon partial pressure and residence time of 2 s. In addition, with the technology of the second injecting steam in ethylene cracking used in paraffin cracking, producing coke in paraffin cracking furnace has been markedly reduced. (c) 2007 Elsevier B.V. All rights reserved

Comparative study of lipid production from cellulosic ethanol fermentation wastewaters by four oleaginous yeasts

The biochemical treatment of cellulosic ethanol wastewater (CEW) is considered to be an ideal green process. To screen out the best oleaginous yeastfor the utilization of cellulosic ethanol wastewater, four oleaginous yeasts (Trichosporon cutaneum, Rhorosporidium toruloides, Cryptococcus albidus and T. coremiiforme) were compared to assess their abilities for lipid production in terms of biomass production, lipid content and lipid yield. Furthermore, thechemical oxygen demand (COD) conversion rate, COD degradation and fatty acid composition were calculated to analyze the effect of wastewaters treatment. According to the fermentation results, the highest biomass and lipid yield of T. cutaneum in CEW were 20.945 and 1.56g/L, respectively, while the R. toruloides reached the highest lipid content (17.32%). The maximum conversion rates of T. cutaneum are 73.64 and 6.06%, respectively, in terms of conversion yield of biomass/COD and lipids/COD. The content of fatty acids showed that after six days' fermentation, T. coremiiforme obtained the highest unsaturated fatty acid content, the content of C18:1 and C18:2 was 57.64%. This study suggests that T. cutaneum has great potential for lipid production and wastewaters treatment from cellulosic ethanol fermentation

Effect of Rolling Parameters on Room-Temperature Stretch Formability of Mg–2Zn–0.5Ca Alloy

In this work, Mg–2Zn–0.5Ca (wt.%) alloy sheets fabricated according to various rolling parameters were evaluated to investigate the effect of rolling parameters on room-temperature stretch formability. The sheet rolled at 360 °C with a pass rolling reduction of 10~33% exhibited the worst I.E. value of 4.4 mm, while the sheet rolled at 360 °C with a pass rolling reduction of 20~50% exhibited the best index Erichsen (I.E.) value of 5.9 mm. Among the sheets, the (0002) basal texture intensity was the weakest, and the grain basal poles split away from the normal direction toward both the rolling direction and the transverse direction. Microstructural and deformation mechanism measurements of stretch forming to 2 mm for the sheet rolled at 360 °C with a pass rolling reduction of 20~50% by electron backscatter diffraction and in-grain misorientation axes showed that there was a higher activity of {10–12} extension twins and that a prismatic slip was initiated. As a result, the weakening of the texture and the broader distribution of basal poles in the plane contributed to the improved formability of the sheet rolled at 360 °C with a pass rolling reduction of 20~50%

Effects of Acetic Acid on Growth and Lipid Production by Cryptococcus albidus

The cell growth and lipid accumulation process of Cryptococcus albidus were investigated using acetic acid as the sole carbon source at different concentrations. C. albidus showed high tolerance to acetic acid at a high concentration of 30 g L-1. The highest lipid content (32.69 +/- A 0.50 %) and lipid yield (0.96 +/- A 0.05 g L-1) were both obtained in the medium with an initial acetic acid concentration of 30 g L-1 on day five. Interestingly, the maximum lipid content and lipid yield was obtained on a different day in a medium with different acetic acid concentration. The fatty acid composition of the lipids accumulated by C. albidus was 16-23 % palmitic acid (C16:0), 3-5 % linolenic acid (C18:3), 42-51 % linoleic acid (C18:2) and 23-27 % oleic acid (C18:1), which was similar to that of soybean oil; thus, this microbial oil has great potential value as a renewable biodiesel feedstock. This work also provides valuable information for further research to use cheap substrates containing a high concentration of acetic acid (such as lignocellulosic hydrolysates), which is an economical and environmentally friendly form of microbial oil production

Effective Recovery of Au from Low-Concentration Solutions by a Self-Synthesized Mesoporous Resin Modified by Dimethylamine

In this study, the recovery of Au(III) from low-concentration HAuCl4 solutions was systematically investigated by a self-synthesized dimethylamine-modified mesoporous resin (DMR). The apparent morphology and pore structure of the DMR were characterized, and the adsorption property of the DMR was studied by static adsorption experiments to evaluate the effects of pH value, adsorbent dosage, and initial concentration of AuCl4-on the Au(III) adsorption from low-concentration HAuCl4 solutions. At 298 K and pH 2.0, the adsorption capacity of Au(III) was 221.16 mg/g and the recovery of Au(III) was 95%. In addition, the adsorption isotherms, thermodynamics, and kinetics were determined and modeled. The results showed that the Langmuir isotherm model and the pseudo-first-order model were more fitted to depict the adsorption of Au(III) onto the DMR, indicating that Au(III) was monolayer-adsorbed onto the surface of the DMR via chemical sorption. Delta G(0) 0 indicated that the process was spontaneous and endothermic. The adsorption capacity of Au(III) was much higher than that reported in the literature due to the coordination interaction and electrostatic force between the amino groups and -AuCl4-, which indicated that the DMR was an adsorbent with great application potential for the recovery of Au from low-concentration solutions