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Optimizing the retaining ring structure can improve the quality of Chemical Mechanical Polishing (CMP). This study establishes a two-dimensional Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) model, while the model is validated by experiments. The results graphically demonstrate the influence of the retaining ring groove design on the motion of the slurry abrasive particles. The size of the retaining ring groove appears to have a threshold value, above which the abrasives start to have significant distribution in the wafer region. As the groove size continues to increase, the number of abrasives entering the ring increases abruptly and oscillates at specific nodes. The abrasive transfer rate increases with the number of grooves in the early stage but reaches a limit at a certain number of grooves. Meanwhile, the retaining ring position affects the transfer of the abrasives. This study provides a base for optimizing the design of retaining rings.
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http://dx.doi.org/10.3390/ma16010062 | DOI Listing |
Eur J Pharm Sci
September 2025
Department of Organic Chemistry, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary. Electronic address:
Platinum-group metal half-sandwich complexes are considered to be potential replacements of the clinically widely used platins which have several side effects and tend to cause resistance to develop. In our previous works, we used a range of 2-pyridyl-substituted N- and C-glycosyl heterocycles as N,N-chelating ligands to prepare ruthenium(II), osmium(II), iridium(III) and rhodium(III) polyhapto arene/arenyl half-sandwich complexes. Some of these complexes, particularly with the C-glucopyranosyl isoxazole derived ligand in its O-perbenzoylated form, exhibited greater anticancer efficiency than cisplatin and had minimal or negligible effects on non-transformed fibroblasts.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
School of Materials Science and Engineering, Taizhou University, Taizhou 318000, China. Electronic address:
The sequential preparation of perovskite solar cells (PSCs) has received widespread concern for its use in large-scale perovskite modules and perovskite/silicon tandem solar cells. However, the instability of the PbI precursor solution and the incomplete reaction of ammonium salts hinder the industrialization of PSCs. Here, by introducing phthalamide (PA) into PbI solution, the carbonyl oxygen of PA molecules undergoes a bidentate coordination reaction with Pb to form an octahedral coordination structure, and the nitrogen atom in the -NH group exhibits weakly acidic properties due to the conjugation effect.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Department of Advanced Medical Technologies, National Cerebral and Cardiovascular Center, Suita, Osaka 564-8565, Japan.
In mammals, sperm formation is completed in the seminiferous tubules within the testis, and sperm maturation occurs during the epididymal transit of the spermatozoa. Sperm morphology drastically changes when abnormal spermatozoa migrate from the testis to the epididymis. Detailed molecular mechanisms for sperm survival in the epididymis have not been determined yet.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
July 2025
College of Pharmacy, Nanjing University of Chinese Medicine Nanjing 210023, China Jiangsu Key Laboratory of Chinese Medicine Processing Nanjing 210023, China Engineering Center of State Ministry of Education for Standardization of Chinese Medicine Processing Nanjing 210023, China.
Traditional Chinese medicine(TCM) processing is a specialized pharmaceutical technique with the primary objective of reducing the toxicity of medicinal substances. Euphorbia pekinensis, E. ebracteolata, and E.
View Article and Find Full Text PDFDent Med Probl
September 2025
Department of Dental Materials and Prosthesis, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, Brazil.
Background: Cleaning overdentures is challenging due to their complex metallic structures, which often create small and irregular areas that are difficult to clean. Thus, it is necessary to find an effective and safe method for their maintenance.
Objectives: The aim of the study was to evaluate the effects of hygiene methods on the dimensional changes and retention force of the O-ring system over a simulated two-year period.