sj-rar-1-dcm-10.1177_17504813231158526 – for A contrastive study of discoursal emotions between China’s and American newspapers from the perspective of Socio-emotional Theory: The case of the reports on Hong Kong National Security Law

sj-rar-1-dcm-10.1177_17504813231158526 for A contrastive study of discoursal emotions between China’s and American newspapers from the perspective of Socio-emotional Theory: The case of the reports on Hong Kong National Security Law by Zhuo Peng and Jianbo Hou in Discourse & Communication</p

Copolymerization of Ethylene and 1,4–Pentadiene: Structure Characterization and Reaction Mechanism

Copolymerization of ethylene and 1,4-pentadiene was conducted by using a homogeneous catalyst to understand the insertion mode of 1,4-pentadiene. The polymer microstructure of the synthesized material was subjected to structural characterization using quantitative NMR spectroscopy, diffusometry, two-dimensional correlation spectroscopy, and selectively refocused insensitive nuclei enhanced by polarization transfer (Sel-RINEPT). The multimodal NMR characterization allows effective differentiation of chain ends and backbone signals, filters irrelevant spectral information, and provides site-specific information to achieve unambiguous structural elucidation. The experimental results reveal that pentadiene has been primarily converted to cis- and trans-dialkyl-substituted cyclohexane moieties along the polymer backbone over the course of polymerization. The analysis also confirms that unreacted pendant allyl groups from pentadiene remain at a concentration that is significantly lower than the cyclic structures. In comparison to the literature results, some discrepancies in structural assignment have been identified and the results will be discussed. Detailed molecular structure elucidation provides critical insights into advancing the understanding of the reaction mechanism

Development of Improved Amidoquinoline Polyolefin Catalysts with Ultrahigh Molecular Weight Capacity

A new synthetic route to amidoquinoline olefin polymerization catalysts has been developed involving significantly less expensive and more readily available starting materials. The new methodology was used to prepare <i>N</i>-mesityl-2-methylquinolin-8-amine, which in turn was converted into trialkyl complexes of Hf, Zr, and Ti. The new complexes were characterized by elemental analysis, 1D and 2D NMR spectroscopy, and X-ray crystallography. A batch reactor ethylene/1-octene copolymerization evaluation at 140 °C showed that the new Hf congener outperformed a series of previously reported molecular olefin polymerization catalysts. In particular, the new Hf catalyst exhibits excellent activity and a remarkable capacity to produce ultrahigh molecular weight copolymers at elevated reaction temperatures

Minimal Proton Channel Enables H₂ Oxidation and Production with a Water-Soluble Nickel-Based Catalyst

Hydrogenase enzymes use first-row transition metals to interconvert H₂ with protons and electrons, reactions that are important for the storage and recovery of energy from intermittent sources such as solar, hydroelectric, and wind. Here we present Ni­(P^Cy₂N^Gly₂)₂, a water-soluble molecular electrocatalyst with the amino acid glycine built into the diphosphine ligand framework. Proton transfer between the outer coordination sphere carboxylates and the second coordination sphere pendant amines is rapid, as observed by cyclic voltammetry and FTIR spectroscopy, indicating that the carboxylate groups may participate in proton transfer during catalysis. This complex oxidizes H₂ (1–33 s^–1) at low overpotentials (150–365 mV) over a range of pH values (0.1–9.0) and produces H₂ under identical solution conditions (>2400 s^–1 at pH 0.5). Enzymes employ proton channels for the controlled movement of protons over long distancesthe results presented here demonstrate the effects of a simple two-component proton channel in a synthetic molecular electrocatalyst

Interaction of Au with Thin ZrO₂ Films: Influence of ZrO₂ Morphology on the Adsorption and Thermal Stability of Au Nanoparticles

The model catalysts of ZrO₂-supported Au nanoparticles have been prepared by deposition of Au atoms onto the surfaces of thin ZrO₂ films with different morphologies. The adsorption and thermal stability of Au nanoparticles on thin ZrO₂ films have been investigated using synchrotron radiation photoemission spectroscopy (SRPES) and X-ray photoelectron spectroscopy (XPS). The thin ZrO₂ films were prepared by two different methods, giving rise to different morphologies. The first method utilized wet chemical impregnation to synthesize the thin ZrO₂ film through the procedure of first spin-coating a zirconium ethoxide (Zr­(OC₂H₅)₄) precursor onto a SiO₂/Si­(100) substrate at room temperature followed by calcination at 773 K for 12 h. Scanning electron microscopy (SEM) investigations indicate that highly porous “sponge-like nanostructures” were obtained in this case. The second method was epitaxial growth of a ZrO₂(111) film through vacuum evaporation of Zr metal onto Pt(111) in 1 × 10^–6 Torr of oxygen at 550 K followed by annealing at 1000 K. The structural analysis with low energy electron diffraction (LEED) of this film exhibits good long-range ordering. It has been found that Au forms smaller particles on the porous ZrO₂ film as compared to those on the ordered ZrO₂(111) film at a given coverage. Thermal annealing experiments demonstrate that Au particles are more thermally stable on the porous ZrO₂ surface than on the ZrO₂(111) surface, although on both surfaces, Au particles experience significant sintering at elevated temperatures. In addition, by annealing the surfaces to 1100 K, Au particles desorb completely from ZrO₂(111) but not from porous ZrO₂. The enhanced thermal stability for Au on porous ZrO₂ can be attributed to the stronger interaction of the adsorbed Au with the defects and the hindered migration or coalescence resulting from the porous structures