crosslinking [2,3] and metal ion chelation processes. [4,5] Thus, up to now, great efforts have been made to incorporate DOPA or catechol groups in a broad range of designed polymers to get mussel-inspired adhesives, which showed good bonding performances both at dry and underwater conditions. These polymers were generally named as "catecholfunctionalized polymers" (CFPs).Up to now, notable accomplishments have been achieved by using CFPs for high performance adhesion at atmospheric environment. Yu and Deming and co-workers reported the synthesis of DOPA-containing copolypeptides, exhibiting a bonding strength of 4.0 MPa on aluminum. [6] Wilker et al. synthesized poly[(3,4-dihydroxystyrene)-co-styrene] via anionic polymerization method, which achieved a bonding strength of 11 MPa on aluminum by using CaCO 3 particles as reinforcing materials. [7] Subsequently, they also incorporated the CFPs with poly(lactic acid) [8][9][10] or pendant oligo(ethylene glycol) moieties [4] to produce biodegradable/biocompatible adhesives with good dry-state bonding strength. Wan et al. synthesized catechol-functionalized poly(vinyl alcohol) via esterification reactions [11] and acetal formation reactions, [12] exhibiting bonding strengths of 4.0 MPa on glass and 14.9 MPa on stainless steel, respectively. Kaneko et al. synthesized a hyperbranched CFP via thermal polycondensation reaction between 3,4-dihydroxycinnamic acid and 4-hydroxycinnamic acid, which showed a bonding strength of ≈10 MPa on steel. [13] Then, they also prepared a similar hyperbranched polymer system with the bonding strength on steel up to 15 MPa. [14] However, despite great progress, the bonding strength of most reported CFPs on metal substrates is smaller than 15 MPa. Recently, Messersmith and co-workers [15] and Detrembleur and co-workers [16] separately reported the synthesis of catechol-functionalized polybenzoxazines and polyhydroxyurethanes, which were used to prepare thermoset adhesive materials with excellent bonding strength of 20.5 MPa on aluminum and 22.1 MPa on stainless steel, respectively. To our knowledge, these two polymers represent the best adhesive materials among CFPs for dry-state adhesion on metal Marine mussels have the ability to cling to various surfaces at wet or underwater conditions, which inspires the research of catechol-functionalized polymers (CFPs) to develop high-performance adhesive materials. However, these polymeric adhesives generally face the problems of complex synthetic route, and it is still high challenging to prepare CFPs with excellent adhesive performance both at dry and underwater conditions. Herein, a mussel-inspired alternating copolymer, poly(dopamine-alt-2,2-bis(4-glycidyloxyphenyl) propane) (P (DA-a-BGOP)), is synthesized in one step by using commercially available monomers through epoxy-amino click chemistry. The incorporation of polar groups and rigid bisphenol A structures into the polymer backbone enhances the cohesion energy of polymer matrix. The alternating polymer structure endows the polymers with high...

Microcellular injection molding of polypropylene and glass fiber composites (PP-1684/ GF-950) was performed using supercritical nitrogen as the physical blowing agent. Based on design of experiment matrices, the influences of glass fiber content and operating conditions on cell structure, glass fiber orientation and mechanical properties of molded samples were studied systematically. The results showed the cell morphology and glass fiber orientation of foaming parts were definitely influenced by the cooling and shear effects. The mechanical properties of foamed polypropylene-glass fiber composites could be effectively enhanced by improving the cell morphology, dispersion state and orientation of the glass fiber at optimal weight percentage w GF =w PP ¼ 11:8%. And the optimal conditions for injection molding were obtained by analyzing the signal-to-noise ratio analysis of the mechanical properties of the molded samples, which were a shot size of 36 mm, a supercritical N 2 weight percentage of 0.4%, an injection speed of 60%, a melt temperature of 190 C and a mold temperature of 70 C. The molded specimens of polypropylene-glass fiber composites, produced under those optimal conditions, exhibited very uniform fiber dispersion and microcellular structures with an average cell size less than 30 mm. And the mechanical properties normalized by weight ratio of the microcellular samples were increased significantly, especially the impact strength.

In recent years, the public security department has insisted on technology to promote the high-quality development of public security work in the new era. It not only builds a three-dimensional patrol and defence system, but improve the level of patrol, defence and control management vigorously. At present, an intelligence-aided patrol system has been initially formed, and video patrols and law enforcement duty supervision have been carried out. However, the application of new technologies and the innovation of policing mechanisms in public security departments still have some problems. For example, unbalanced regional development, insufficient deepening of intelligent applications and insufficient systematization of applications, which greatly restrict the effectiveness of public security patrol and defence in practice. Based on this, our study identifies the crime hotspots in the city through EXCEL data analysis, and identifies them as patrol points. By applying the shortest route algorithm in the genetic algorithm, a precise patrol route is formed. Based on this, the precise patrol route is displayed on a map using a visualization tool and then fed back to the police terminal equipment. This project enables police patrols to be more accurate and patrol routes to be optimized. It improves the police patrol system and provides the basis for the construction of an intelligent patrol system.