Copper-Catalyzed Oxidative Coupling of Quinazoline-3-Oxides: Synthesis of O-Quinazolinic Carbamates.

Organic carbamates represent a kind of privileged structures in both organic chemistry and industry. Despite the fact that the synthesis of alcohol-based carbamates has been well studied, an efficient access to hydroxamic acid-based carbamates is less explored due to the nucleophilicity of both O and N atoms in hydroxamic acids. Herein, we report a copper-catalyzed oxidative coupling of quinazoline-3-oxides and formamides for the synthesis of O-quinazolinic carbamates. This protocol is featured with practicability, simple starting materials, and operational simplicity.

Analysis of the Spatial-Temporal Evolution of Urbanization Quality in Zhejiang Province, China.

Taking cities in Zhejiang Province of China from 2011 to 2020 as the research object, a multi-dimensional urbanization quality evaluation index system was constructed using the comprehensive analysis method, and the urbanization quality of 11 cities in Zhejiang Province was quantitatively measured using the entropy weight method. The system classification and time-space evolution analysis were carried out using ArcGIS software (Environmental Systems Research Institute, Inc., RedLands, CA, USA) to comprehensively study the evolution characteristics and influencing factors of the urbanization quality of cities in Zhejiang Province. This study provides a reference for local governments to formulate feasible urbanization development strategies and policies to promote the high-quality development of urbanization and for the construction of new urbanization in other provinces and cities.

Information Disclosure Impacts Intention to Consume Man-Made Meat: Evidence from Urban Residents' Intention to Man-Made Meat in China.

Meat substitutes such as man-made meat are emerging to promote low-carbon healthy consumption, mitigate climate change, and assist healthy economic development; however, most consumers seem reluctant to make the transition. While profound social change may be required to make significant progress in this area, limited efforts have been made to understand the psychological processes that may hinder or facilitate this transition. To clearly identify the factors influencing the public's intention to consume man-made meat and their influencing paths, this study analyzes the mechanism by which man-made meat information disclosure affects the public's intention to consume these products based on the social cognitive theory of "awareness-situation-behavior" and using structural equation modeling, with residents of seven Chinese cities as examples (647 respondents). The results of this study yielded three main findings. First, low-carbon awareness, personal social responsibility awareness, and man-made meat risk perception significantly influence the public's intention to consume man-made meat, with risk perception having the greatest influence (-0.434). Second, low-carbon awareness and man-made meat risk perception have a significant interaction effect on the public's intention to consume man-made meat (-0.694). Third, man-made meat information disclosure has the most significant moderating effect on the relationship between low-carbon awareness and the public's intention to consume man-made meat, as well as a moderating effect on the relationship between man-made meat risk perception and the public's intention to consume man-made meat.

Effects of Three-Dimensional Graphene-Carbon Nanotube Hybrid on the Mechanical Properties and Microstructure of Cement Paste.

This work experimentally studies the mechanical properties and microstructure of cementitious composites reinforced with a three-dimensional graphene-carbon nanotube (CNT) hybrid. Firstly, the graphene-CNT (GC) hybrid is dispersed in cement pastes using ultrasonication and surfactant, and then, the effect of the GC hybrid on the early hydration of the cement pastes is investigated. The experimental results show that adding the GC hybrid shortens the setting stage of cement hydration and accelerates the early hydration process. Moreover, the macro- and micro-mechanical properties of each group are evaluated. The 7- and 28-day strength of the cement pastes improves with addition of the GC hybrid. Finally, the microstructural analysis demonstrates that the GC hybrid is reasonably well distributed in cement and forms a spatial network, which could bridge the cracks and compact the cementitious matrix.

Study on Spatial Geometric Similarity Based on Conformal Geometric Algebra.

The study of spatial geometric similarity plays a significant role in spatial data retrieval. Many researchers have examined spatial geometric similarity, which is useful for spatial analysis and data retrieval. However, the majority of them focused on objects of the same type. Methods to support the spatial geometric similarity computation for different types of objects are rare, a systematic theory index has not been developed yet, and there has not been a comprehensive computational model of spatial geometric similarity. In this study, we conducted an analysis of the spatial geometric similarity computation based on conformal geometric algebra (CGA), which has certain advantages in the quantitative computation of the measurement information of spatial objects and the qualitative judgment of the topological relations of spatial objects. First, we developed a unified expression model for spatial geometric scenes, integrating shapes of objects and spatial relations between them. Then, we established a model for the spatial geometric similarity computation under various geographical circumstances to provide a novel approach for spatial geometric similarity research. Finally, the computation model was verified through a case study. The study of spatial geometric similarity sheds light on spatial data retrieval, which has scientific significance and practical value.

Bending Fatigue Behaviour and Fatigue Endurance Limit Prediction of 20Cr2Ni4A Gear Steel after the Ultrasonic Surface Rolling Process.

To study the effect of the surface properties on the bending fatigue performance of heavy-duty gear steel, the authors of this paper used the ultrasonic surface rolling process (USRP) to strengthen 20Cr2Ni4A carburized gear steel. USRP is a novel technique in which the ultrasonic technology is incorporated into the concept of conventional deep rolling. In this study, we illustrated how the surface properties and cross-section mechanical property influence the three-point bending fatigue life of the samples before and after USRP treatment. At the same time, the predicted failure probability-stress-number of cycles (P-S-N) curve was drawn, and the fatigue fracture was analysed. The results show that the fatigue limit increased from 651.36 MPa to 918.88 MPa after USRP treatment. The fatigue source is mainly from the sample interior or surface scratches, and the fatigue performance is positively correlated with the results of the material surface roughness, surface residual stress and surface hardness. At the same time, combined with the change in the phase structure, dislocation structure, residual stress and hardness of the cross section of the material, it is found that the USRP process turns the steel into a gradient material with five layers. Finally, the coupling mechanism between the ultrasonic surface strengthening deformation layer and the carburized layer of 20Cr2Ni4A carburized gear steel is presented, and the grain structure distribution diagram of the section of the 20Cr2Ni4A model after surface strengthening treatment was simulated. The mechanism that influenced the fatigue performance after USRP treatment is explained from the perspectives of the surface and cross section of the samples.

Microwave-Assisted Cp*CoIII-Catalyzed C-H Activation/Double C-N Bond Formation Reactions to Thiadiazine 1-Oxides.

A microwave-assisted, Cp*CoIII-catalyzed direct C-H activation/double C-N bond formation reaction of simple NH-sulfoximines with 1,4,2-dioxazol-5-ones to produce diverse thiadiazine-1-oxides is reported. The reaction tolerates a broad range of functional groups under external oxidant-free conditions and only releases CO2 and H2O as the sole byproducts. The preliminary mechanistic studies revealed an electrophilic metalation pathway is likely involved in the reaction.

Silver-mediated selective oxidative cross-coupling between C-H/P-H: a strategy to construct alkynyl(diaryl)phosphine oxide.

A direct oxidative cross-coupling between terminal alkynes and secondary phosphine oxides was developed. This approach provides an efficient way to construct alkynyl di(phenyl) phosphine oxides from basic materials, and in this process, the silver salts act as a key promoter.