Cu(i)/Amino Acid Catalyzed Coupling Reactions of Aryl Halides and Nucleophiles: Applications in Large-scale Production

Amino acids can be used as ligands to promote Ullmann-type coupling reactions. This review briefly discusses how L-proline, 4-hydroxy-L-proline and N,N-dimethylglycine can serve as the ideal ligands for copper-catalyzed coupling of aryl halides with different nucleophiles. Seven examples of applications of copper/amino acid catalyzed reactions in large-scale preparations are described

End-to-End Quantum-like Language Models with Application to Question Answering

Language Modeling (LM) is a fundamental research topic ina range of areas. Recently, inspired by quantum theory, a novel Quantum Language Model (QLM) has been proposed for Information Retrieval (IR). In this paper, we aim to broaden the theoretical and practical basis of QLM. We develop a Neural Network based Quantum-like Language Model (NNQLM) and apply it to Question Answering. Specifically, based on word embeddings, we design a new density matrix, which represents a sentence (e.g., a question or an answer) and encodes a mixture of semantic subspaces. Such a density matrix, together with a joint representation of the question and the answer, can be integrated into neural network architectures (e.g., 2-dimensional convolutional neural networks). Experiments on the TREC-QA and WIKIQA datasets have verified the effectiveness of our proposed models

A words-of-interest model of sketch representation for image retrieval

In this paper we propose a method for sketch-based image retrieval. Sketch is a magical medium which is capable of conveying semantic messages for user. It’s in accordance with user’s cognitive psychology to retrieve images with sketch. In order to narrow down the semantic gap between the user and the images in database, we preprocess all the images into sketches by the coherent line drawing algorithm. During the process of sketches extraction, saliency maps are used to filter out the redundant background information, while preserve the important semantic information. We use a variant of Words-of-Interest model to retrieve relevant images for the user according to the query. Words-of-Interest (WoI) model is based on Bag-ofvisual Words (BoW) model, which has been proven successfully for information retrieval. Bag-of-Words ignores the spatial relationships among visual words, which are important for sketch representation. Our method takes advantage of the spatial information of the query to select words of interest. Experimental results demonstrate that our sketch-based retrieval method achieves a good tradeoff between retrieval accuracy and semantic representation of users’ query

Comprehensive profiling of rhizome-associated alternative splicing and alternative polyadenylation in moso bamboo (Phyllostachys edulis).

Moso bamboo (Phyllostachys edulis) represents one of the fastest-spreading plants in the world, due in part to its well-developed rhizome system. However, the post-transcriptional mechanism for the development of the rhizome system in bamboo has not been comprehensively studied. We therefore used a combination of single-molecule long-read sequencing technology and polyadenylation site sequencing (PAS-seq) to re-annotate the bamboo genome, and identify genome-wide alternative splicing (AS) and alternative polyadenylation (APA) in the rhizome system. In total, 145 522 mapped full-length non-chimeric (FLNC) reads were analyzed, resulting in the correction of 2241 mis-annotated genes and the identification of 8091 previously unannotated loci. Notably, more than 42 280 distinct splicing isoforms were derived from 128 667 intron-containing full-length FLNC reads, including a large number of AS events associated with rhizome systems. In addition, we characterized 25 069 polyadenylation sites from 11 450 genes, 6311 of which have APA sites. Further analysis of intronic polyadenylation revealed that LTR/Gypsy and LTR/Copia were two major transposable elements within the intronic polyadenylation region. Furthermore, this study provided a quantitative atlas of poly(A) usage. Several hundred differential poly(A) sites in the rhizome-root system were identified. Taken together, these results suggest that post-transcriptional regulation may potentially have a vital role in the underground rhizome-root system

Influence of Cutter Errors on Forming Accurate Variable Hyperbolic Circular Arc Tooth Trace Cylindrical Gears

The cutter error is an important factor in the accurate forming of the variable hyperbolic circular arc tooth trace (VH-CATT) cylindrical gears. Also, the study of the relationship between the cutter error and the forming of accurate teeth is beneficial for the gear modification design and the improvement in contact performance. Firstly, based on the principle of forming VH-CATT cylindrical gears, the sources of error in the tooth forming related to accuracy were analysed, including the errors in the cutter position and the cutter geometry, such as the error of rotation around the x-axis g, the error of rotation around the y-axis b, the error of translation along the x-axis Δx, the error of translation along the y-axis Δy, the error of translation along the z-axis Δz, the pressure angle error Δa and the tooth line radius error ΔRT. Next, based on the meshing theory and processing, an ideal tooth surface equation and a tooth surface equation with cutter errors were derived, and the tooth surface reconstruction was done. Then, the gear tooth thickness error was defined to characterize the accuracy of gear forming. Finally, the influences of the cutter error on the tooth thickness error and gear contact were investigated. The study shows that all cutter errors have certain influence on the tooth thickness error, contact area and load distribution; Δx has basically no effect on the gear tooth thickness error; Δx and g make the actual meshing point deviate from the middle section. The study content and the applied methods are helpful in the tooth surface error traceability, the counter-adjustment of the tooth surface processing and the modification design. This study provides also a basis for gear design and load-bearing contact analysis