Polymers are the backbone of drug delivery. Electrospinning has greatly enriched the strategies that have been explored for developing novel drug delivery systems using polymers during the past two decades. In this study, four different kinds of polymers, i.e., the water-soluble polymer poly (vinyl alcohol) (PVA), the insoluble polymer poly(ε-caprolactone) (PCL), the insoluble polymer Eudragit RL100 (ERL100) and the pH-sensitive polymer Eudragit S100 (ES100) were successfully converted into types of tri-layer tri-polymer core–shell fibers through bi-fluid coaxial electrospinning. During the coaxial process, the model drug metronidazole (MTD) was loaded into the shell working fluid, which was an emulsion. The micro-formation mechanism of the tri-layer core–shell fibers from the coaxial emulsion electrospinning was proposed. Scanning electron microscope and transmission electron microscope evaluations verified the linear morphology of the resultant fibers and their obvious tri-layer multiple-chamber structures. X-ray diffraction and Fourier transform infrared spectroscopy measurements demonstrated that the drug MTD presented in the fibers in an amorphous state and was compatible with the three polymeric matrices. In vitro dissolution tests verified that the three kinds of polymer could act in a synergistic manner for a prolonged sustained-release profile of MTD in the gut. The drug controlled-release mechanisms were suggested in detail. The protocols reported here pioneer a new route for creating a tri-layer core–shell structure from both aqueous and organic solvents, and a new strategy for developing advanced drug delivery systems with sophisticated drug controlled-release profiles.

Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL Convention), adopted in October 2008, was dedicated to addressing environmental issues caused by ships, especially in ports, inland waterways, and some sea areas with concentrated routes and high navigational density. This study utilizes a regional-level ship dataset to assess the influences of emission-control areas (ECAs) on the ecological shipbuilding industry by fitting the policy utility through the synthetic control method and testing robustness via the difference-in-differences method. The outcomes of this study show that the cumulative new orders for eco-designed ships in China, The Netherlands, Republic of Korea, the UK, and the USA increased by 3401, 81, 234, 549, and −1435, respectively, after the implementation of ECAs. Compared to the implementation of ECAs, the increases were about 32%, 20%, 41%, 66%, and −83%, respectively.

Although previous research ignores other subsidy groups, we conduct a comprehensive study. In our closed-loop supply chain model, the manufacturer can produce either new products or remanufactured products of end-of-life products recycled by independent recyclers. Our core objective is to explore the production and recycling strategies of the two products under different government subsidy plans and which groups the government subsidy plans should target. Considering the consumers’ discount perception and uncertainty of recycling quantity, we construct four game scenarios: (1) no subsidy (Scenario N); (2) subsidy for the manufacturer (Scenario M); (3) subsidy for the recycler (Scenario R); (4) subsidy for consumers (Scenario C). The results show that the corporate profits and social welfare under scenario C are higher than those under other scenarios. If the government adopts scenario C, enterprise profits and social welfare will always be higher, but the downside is that government expenditure will also be higher. If considering the limited government funds, the government can set a medium subsidy level. Scenario M will bring sub-optimal social welfare to the government. For scenario R, government subsidies stimulate the recycling of end-of-life products and help recyclers increase their profits, but from the manufacturer’s perspective, manufacturers may resist this scenario.

In recent years, the Chinese central government and coastal provincial governments have promulgated a series of Coastal Ocean Pollution Prevention and Control Programs (COPPCP). Whether the government’s COPPCP can achieve policy synergy will affect the level of marine pollution governance. This study constructs a two-dimensional assessment framework of policy “subject department”–”content theme” and conducts a comprehensive evolution of policy synergy from objective, process, and state perspectives. From the subject department dimension, the study used social network analysis to find that interdepartmental collaboration was not done well overall. The policy synergy process is difficult to be guaranteed. Meanwhile, the structure of departmental synergy networks in different provinces shows differences and can be divided into three types of governments with single-core, multi-core, and vertical synergy. In the content synergy dimension, it was found by the Chinese Bidirectional Encoder Representations from Transformers-Whole Word Masking (BERT-WWM) model that the policy content is mainly focused on four themes of marine ecological protection (MEP), marine pollution control (MPC), land-based pollution reduction (LPR), and safeguard measures (SAM). The three types of governments show different performances on the four theme synergies. The governments perform well in the objective synergy; however, it is difficult for them to agree on the policy tool synergy, and the status of policy synergy is difficult to maintain. This paper adopts the BERT-WWM model instead of the manual coding method in the previous policy content analysis, enhancing the evaluation’s objectivity. The study results will provide a reference for further improving marine pollution governance systems in developing countries.