China
Africa
Explore chapters and articles related to this topic
“Soft” Chemical Synthesis and Manipulation of Semiconductor Nanocrystals
Published in Victor I. Klimov, Nanocrystal Quantum Dots, 2017
Jennifer A. Hollingsworth, Victor I. Klimov
High-quality NQDs absorbing and emitting in the infrared have also been prepared by way of a surfactant-stabilized pyrolysis reaction. PbSe colloidal QDs can be synthesized from the precursors: lead oleate (prepared in situ from lead(II)acetate trihydrate and oleic acid)23 and TOPSe.10,23 TOP and oleic acid are present as the coordinating solvents, whereas phenyl ether, a non-coordinating solvent, provides the balance of the reaction solution. Injection and growth temperatures were varied (injection: 180°C–210°C; growth: 110°C–130°C) to control particle size from ~3.5 to ~9 nm in diameter.23 The particles respond to “traditional” size-selection precipitation methods, allowing the narrow as-prepared size dispersions (σ ≤ 10%) to be further refined (σ = 5%) (Figure 1.4).10 Oleic acid provides excellent capping properties as PL quantum efficiencies, relative to IR dye no. 26, can approach 100% (Figure 1.5).23 Importantly, PbSe NQDs are substantially more efficient IR emitters than their organic-dye counterparts and provide enhanced photostability compared to existing IR fluorophores. More recently, a synthetic route to large-size PbSe NQDs (>8 nm) has been described that permits particle-size-tunable mid-infrared emission (>2.5 μm) with efficient, narrow-bandwidth emission at energies as low as 0.30 eV (4.1 μm).27
Palladium Promoted by Metal Ions. Oxidation State of Promoter During Liquid Phase Hydrogenations
Published in Mike G. Scaros, Michael L. Prunier, Catalysis of Organic Reactions, 2017
Z. Bodnar, T. Mallat, A. Baiker
When the catalyst potential is negative with respect to bulk metal deposition (position A), the metal ion can be reduced to bulk and adsorbed metal on the Pd surface. This is the general situation during metal ion promotion with Pb2+, Sn2+, Cd2+, Tl+, Cu2+, Hg2+, Ag+ or Bi3+ in neutral aqueous and alcoholic solutions. This conclusion can be generalized to all platinum metals as their potential is determined by adsorbed hydrogen. As an example, Figure 2 shows the anodic polarization curve of a Pd/C catalyst promoted with Cu in an aqueous Cu(NH3)4(0H)2 solution in a hydrogen atmosphere.15 The doublet at 0.3–0.4 V points to the oxidation of bulk Cu and the peak around 0.55 V is due to the ionization of adsorbed Cu. The 0.2 V potential shift corresponds to the difference in binding energies of the two structures. Another, well known example is the preparation of Lindlar catalyst by modifying Pd/CaC03 with an aqueous lead(II) acetate solution.14
The leaching of celestite in sodium sulfide solution to produce strontium carbonate
Published in Gülhan Özbayoğlu, Çetin Hoşten, M. Ümit Atalay, Cahit Hiçyılmaz, A. İhsan Arol, Mineral Processing on the Verge of the 21st Century, 2017
M. Erdemoğlu, M. Sarikaya, M. Canbazoğlu
Detection of hydrogen sulfide gas, as analyzed by Lead (II) acetate solution, during the acidic leaching experiments supports the reaction defined by Equation 6. According to Equation 5 the conversion reaction can be written as; () SrSO4+S22−=SrS2(s)+SO42−
Changes in the composition of heavy oil during thermolysis in the presence of molten sodium without hydrogen
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Igor P. Kosachev, Dmitry N. Borisov, Dmitry V. Milordov, Nikolay A. Mironov, Svetlana G. Yakubova, Makhmut R. Yakubov, Airat I. Shamsullin, Tagir S. Aynullov
The composition and properties of the initial oil and its thermolysis products were analyzed. The density and kinematic viscosity were determined. The gas fraction was determined according to the weight difference of heavy oil before and after thermolysis. Coke was separated via filtration through the porous glass filter Schott. The precipitate was transferred to a flask, washed with isopropyl alcohol to remove sodium residues and, then, hydrochloric acid. The latter procedure was aimed at the qualitative determination of sodium sulfide, whose reaction with acids gives hydrogen sulfide. Hydrogen sulfide was detected both organoleptically according to rotten-egg odor and by the darkening of the filter paper soaked by lead (II) acetate solution according to the following reaction:
Exposure to lead on expression levels of brain immunoglobulins, inflammatory cytokines, and brain-derived neurotropic factor in fetal and postnatal mice with autism-like characteristics
Published in Journal of Toxicology and Environmental Health, Part A, 2021
KyeongMin Shin, GyeongDong Lim, Young-Seoub Hong, SoNam Kim, SoRyeon Hwang, JaeHee Lee, SoJung Sin, AhRang Cho, YeonGyeong Kim, Ravi Gautam, JiHun Jo, Manju Acharya, Anju Maharjan, DaEun Lee, Pramod B. K C, ChangYul Kim, Yong Heo, Hyoung-Ah Kim
Lead(II) acetate trihydrate (Pb) (Sigma, Saint Louis, MO, USA) was dissolved in distilled drinking water at a concentration of 0.1 mM. The oral Pb dose was based upon a study by Snyder et al. (2000), which determined that this amount produces blood Pb levels comparable to levels found in childhood Pb intoxication (10–20 μg/dl) (Hauptman, Bruccoleri, and Woolf 2017). To evaluate immune alterations at the fetal stage, pregnant dams were placed on drinking water with (5 litters BTBR-Pb and 4 litters FVB-Pb) or without 0.1 mM Pb acetate (3 litters BTBR-C and 3 litters FVB-C) from GD0 to GD18. To determine immune alterations at the postnatal stage, pregnant dams were administered drinking water with (two litters BTBR-Pb and 5 litters FVB-Pb) or without 0.1 mM Pb acetate (4 litters BRBR-C and 6 litters FVB-C) from GD8 to postnatal day (PND) 21. The timespan from GD8 to PND21 was utilized to initially enable embryo implantation in utero (GD0-GD7 Pb-free) and subsequently to maximize the effects of developmental Pb exposure (Kasten-Jolly, Heo, and Lawrence 2010; Snyder et al. 2000).
Central composite design of heavy metal removal using polymer adsorbent
Published in Journal of Applied Water Engineering and Research, 2021
Nur Amirah Mohd Zahri, Siti Nurul Ain Md Jamil, Luqman Chuah Abdullah, Sim Jia Huey, Mohsen Nourouzi Mobarekeh, Nur Salimah Mohd Rapeia, Thomas Choong Shean Yaw
Cadmium ions (Cd2+) and lead ions (Pb2+) were prepared from cadmium nitrate-tetrahydrate and lead (II) acetate-trihydrate (R&M Chemical, Essex, UK), respectively. Sodium hydroxide (NaOH) (Systerm ChemAR, Shah Alam, Malaysia) and hydrochloric acid (HCl) (Fisher Scientific, Loughborough, UK) were used to adjust the pH of the heavy metal ion solution. The adsorbent of synthetic polymer of amidoxime modified poly(acrylonitrile-co-acrylic acid) (hereinafter referred as polymer adsorbent) was used to remove Cd2+ or Pb2+ ion. The details on polymer adsorbent characterization have been reported in previous work (Zahri et al. 2015).