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Multicomponent polymerization of bis(N-sulfonyl aziridine) with an alcohol and an anhydride allows the facile synthesis of diverse recyclable poly(sulfonamide ester)s.

With the rapid development of e-commerce platforms and new products in China, however, the scrap products such as waste paper, used home appliances and scrap metals that come with them are accumulating in cities, affecting the environment and hygiene. Today, scrap collectors often drive electric tricycles aimlessly to carry out scrap collection. The vehicle path planning is a pressing problem in the recycling process of scrap products from user location points to sorting centers. In order to solve this problem and minimize the cost consumed in the recycling process, this paper solves and analyzes the actual problem based on an improved genetic algorithm, combined with GIS technology. Firstly, based on the characteristics of the scrap recycling process, the shortest path is solved based on GIS software, and then the spatial and distance information such as user location points and sorting points are combined to construct a GIS network to obtain the shortest path. Secondly, this paper establishes a vehicle path planning model for the sorting center considering factors such as actual scrap collectors’ commuting and service time. Then, an improved and optimized genetic algorithm is designed, and then the model is solved. Finally, the solved optimal path of scrap collection is displayed in GIS software. In this paper, the effectiveness of the method is demonstrated by taking Guilin city as an example.

This work is financially supported by the National Natural Science Foundation of China (21801049) and the Opening Project of Key Laboratory of Polymer Processing Engineering (South China University of Technology), Ministry of Education. N.H. acknowledges the support of the King Abdullah University of Science and Technology.

We report an organocatalytic sequential ring-opening polymerization (ROP) approach for the facile synthesis of polysulfonamide-based copolymers. Alcohols and methoxylpolyethylene glycols were initially employed as (macro)initiators for the ROP of N-sulfonyl aziridines to produce well-controlled polymers with the assistance of tosyl isocyanate. Tosyl isocyanate efficiently transformed the hydroxyl species into the tosylcarbamate anion, the initiating site for the ROP of N-sulfonyl aziridines. ROP of e-caprolactone or propylene oxide was then performed in bulk in the presence of the phosphazene base t-Bu-P2 or t-Bu-P4, followed by end-group transformation with tosyl isocyanate and the subsequent ROP of N-sulfonyl aziridines. The synthesized poly(e-caprolactone)-block-polysulfonamide and poly(propylene oxide)-block-polysulfonamide copolymers showed a remarkable control of molar masses and dispersities. Well-defined triblock and 3-arm star-shaped copolymers were successfully prepared from diol and triol initiators.

The outbreak of the COVID-19 pandemic was a sudden disaster for all human beings. To prevent the spread of the pandemic, China used smart facilities to manage it, especially relying on smartphones. This study examines what the impact of the pandemic is on the use of smartphones by seniors, a group that is weaker in the use of smart devices. The study looks at the situation with seniors in the new media environment, seeking to help them cross the digital divide and bring social attention to their plight during the pandemic. The authors conducted in-depth interviews with 52 seniors from first-tier cities in China and then did a discourse analysis of the interviews. The study found that the pandemic increased the smartphone penetration among the seniors, and helped them mitigate the digital divide and increase their social adaptability. However, it is still noteworthy for smartphone addiction.

A facile and effective "grafting from" method by ROP of N-sulfonyl aziridines toward cellulose-g-polysulfonamides has been developed for efficient oil/water separation. The cellulose paper was initially succinylated to transform the hydroxyl to carboxyl acid groups, which act as the initiating sites for the ring-opening copolymerization of fluorescent 2-methyl-1-dansylaziridine and 2-methyl-1-tosylaziridine (TsMAz) towards the grafted cellulose. Both steps are catalyzed by the same compound, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD). The grafted polysulfonamide ratio was up to 136 wt%, and the surface contact angle up to 147°. A one-pot tandem strategy was applied to produce the grafted cellulose paper with a grafting ratio ranging from 96 to 150 % and a contact angle over 127°. The modified cellulose paper material showed promising properties for efficient oil/water separations.

The emergence of online music has brought a great change into the music industry, it also has brought opportunities for the development of music industry. With the emergence and development of the Internet, the traditional music business model cannot adapt to the development of online music anymore, so that online music business model based on Internet thinking need to be established. Based on value chain theory, centered on Internet thinking, this article attempt to set up a new online music business models by analysis of the whole online music industry value chain and analyze the operation strategy and services mode of the business models.

Objective Previous studies have indicated that statin therapy may promote plaque regression. However, the impact of statin therapy on plaque composition has not been clearly elucidated. We performed a meta-analysis to investigate the effect of statin therapy on coronary plaque composition as assessed by virtual histology intravascular ultrasound (VH-IVUS). Methods Online databases were searched from inception to March 1, 2015. Studies providing VH-IVUS volumetric analyses of coronary plaque composition at baseline and follow-up in patients receiving statin therapy were included. Weighted mean difference (WMD) using a random-effects model was used. Results Ten studies involving 682 patients were included. There was a substantial reduction in fibrous volume between baseline and follow-up (WMD: -2.37 mm3, 95% confidence interval (CI) -4.01 to -0.74 mm3, P=0.004), and a significant increase in dense calcium (DC) volume (WMD: 0.89 mm3, 95% CI 0.70 to 1.08 mm3, P