Poly(quaternary ammonium salt-epoxy) grafted onto Ce doped ZnO composite: An enhanced and durable antibacterial agent.

The composite after referred to as P(DMDAAC-AGE)/(Ce-ZnO) was prepared via free radical polymerization by polymer including quaternary ammonium salt and epoxy group which grafted onto the surface of Ce-ZnO. ZnO nanorods, Ce-ZnO nanorods, P(DMDAAC-AGE), P(DMDAAC-AGE)/ZnO composites, P(DMDAAC-AGE)/(Ce-ZnO) composites and commercial antimicrobials were respectively treated on the cotton fabrics and their biological properties were investigated. There is a synergistic effect between Ce-ZnO and N+ from the polymer in the fabric treated with P(DMDAAC-AGE)/(Ce-ZnO) composite so that it had a better antibacterial activity than pure polymer and pure Ce-ZnO. The antimicrobial rate of fabric treated with P(DMDAAC-AGE)/(Ce-ZnO) composite could reach up to 96%. And in order to investigate the durable ability, the fabric was washed multiple times to simulate the daily use washing. The result showed that the fabric still gave a superior antibacterial performance after 11 cycles (the equivalent of 55 times house laundering). Simultaneously, the differences in the amount of P(DMDAAC-AGE)/(Ce-ZnO) composite deposited on the fibers after washing were also investigated.

Inferring and analysis of social networks using RFID check-in data in China.

Social networks play an important role in our daily lives. However, social ties are rather elusive to quantify, especially for large groups of subjects over prolonged periods of time. In this work, we first propose a methodology for extracting social ties from long spatio-temporal data streams, where the subjects are 17,795 undergraduates from a university of China and the data streams are the 9,147,106 time-stamped RFID check-in records left behind by them during one academic year. By several metrics mentioned below, we then analyze the structure of the social network. Our results center around three main observations. First, we characterize the global structure of the network, and we confirm the small-world phenomenon on a global scale. Second, we find that the network shows clear community structure. And we observe that younger students at lower levels tend to form large communities, while students at higher levels mostly form smaller communities. Third, we characterize the assortativity patterns by studying the basic demographic and network properties of users. We observe clear degree assortativity on a global scale. Furthermore, we find a strong effect of grade and school on tie formation preference, but we do not find any strong region homophily. Our research may help us to elucidate the structural characteristics and the preference of the formation of social ties in college students' social network.

Bis(2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl) carbonate.

The title compound, C(21)H(22)O(5), crystallizes with three mol-ecules in the asymmetric unit. In one mol-ecule, two methyl groups are disordered over two positions with a site occupation factor of 0.72 (2) for the major occupancy site. The benzene rings make dihedral angles of 35.3 (6), 29.7 (6) and 40.6 (7)° in the three molecules.

2-(2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-yl-oxy)acetic acid monohydrate.

In the title compound, C(12)H(14)O(4)·H(2)O, the dihydro-benzo-furan ring adopts an envelope conformation with the substituted C atom 0.142 (1) Šout of the least-squares plane. In the crystal, the components are linked via inter-molecular O(water)-H⋯O and O-H⋯O(water) hydrogen-bonding inter-actions, forming a three-dimensional network.

2,2,7,7-Tetra-methyl-2,3,6,7-tetra-hydro-benzofuro[7,6-b]furan.

The title compound, C(14)H(18)O(2), was obtained as a by-product during the preparation of carbofuran phenol. The two dihydro-furan rings are in envelope conformations.

2-Amino-4-tert-butyl-5-(4-chloro-benz-yl)thia-zol-3-ium chloride.

The title compound, C(14)H(18)ClN(2)S(+)·Cl(-), crystallizes with two formula units in the asymmetric unit. The dihedral angles between the mean planes of the chloro-phenyl and thia-zole rings are 87.8 (2) and 88.0 (2)° in the two independent mol-ecules. In the crystal, the anions and cations are connected by N-H⋯Cl hydrogen bonds.

8-Bromo-2-methyl-quinoline.

In the crystal structure of the title compound, C(10)H(8)BrN, the dihedral angle between the two six-membered rings of the quinoline system is 0.49 (16)°. The mol-ecules are packed in a face-to-face arrangement fashion, with a centroid-centroid distance of 3.76 Šbetween the benzene and pyridine rings of adjacent mol-ecules. No hydrogen bonding is found in the crystal structure.