No abstract

Because of the fire scene belonging to the coexistence of mud, ash, oil, and other stains, fire clothing is easy to stain, and frequent washing also reduces the protective performance of clothing and even shortens service life. To improve the self-cleaning properties of aramid fabric, N,N-dimethyl hexamide (DMAC), butyl titanate, tetraethoxysilane, butyl ferrate, polydimethylsiloxane, and N-hexane were prepared and mixed on the surface of the fabric. And the surface morphology, self-cleaning, and flame retardancy of fabric before and after treatment were systematically investigated. The results showed that compared with the untreated fabric, the surface of the treated fabric had a rough microstructure; PDMS/SIO2-TIO2-Fe composite was uniformly coated on the surface of the aramid fabric by the one-step spraying method. The flame retardancy decreased slightly but remained within the standard requirement of the B1 grade. The self-cleaning and anti-fouling properties of the finished aramid fabric were improved obviously. The results provided a theoretical basis for the preparation of high-performance fire-fighting fabrics with the advantages of water-saving, energy-saving, reducing the amount of chemical detergent and being friendly to the environment. The utility model reduced the economic loss and the waste of resources because of the decrease in the function of the fire-fighting clothing caused by the washing and the elimination to a certain extent.

A large number of aromatic substances can be found in so-called coal tar (containing >10,000 individual compounds), which is a mixture of heavy liquid fractions (dense viscous black liquor, tended to solidification) obtained after the pyrolysis of coal (solid product—coke, gas products, and light liquid products are also produced during the process). Volatile monocyclic aromatic hydrocarbons, which are naturally occurring in coal tar, can be exploited as premium raw materials for the production of graphene by chemical vapor deposition (CVD). Moreover, aromatic chemicals (compounds with benzene rings) can produce graphene at lower temperatures than other small-molecule gas feedstocks (for graphene growth via methane gas, the temperature must be at least 900 °C). The intermediate reaction mechanism involved in the creation of graphene from various temperature ranges of monocyclic aromatic hydrocarbons in benzene ring structures has long been a fascinating enigma. Accordingly, in this paper, we analyze the graphene growth pattern of benzene at different temperatures from 300 to 900 °C. For graphene synthesis in the lower temperature range (300~600 °C), analytical experiments show that benzene rings (almost) do not crack during the gas phase process. Thus, the structure of the benzene ring is directly coupled into graphene in the above temperature range. When benzene is more thoroughly transformed into tiny molecules that are deposited on the surface of copper foil at higher temperatures (700~900 °C), graphene is formed by a complex mixture of carbon sources, including gaseous small molecules (methane and ethane) and benzene. Based on the process above, we provide an alternative solution for the large-scale industrial preparation of graphene, with low energy consumption, via low-temperature synthesis of graphene by the CVD method using the coal tar carbon source at 500 °C, which is the optimal growth temperature of the benzene ring.

Background: The transverse facial artery is an important source of zygomaticofacial blood, but its perforator flap is rarely reported. The aim of this study was to investigate the utility of a modified perforator flap based on facial aesthetic units and previous anatomic studies of transverse facial arteries. Methods: All 18 elderly patients with zygomatic facial tumors underwent Mohs surgery. The V-Y and propeller flaps were designed according to the aesthetic unit of the defect site. Only a small portion of the fascia and fat surrounding the blood vessel are left, the rest of the flap is pruned to a thickness closer to the surrounding tissues. The surgical effect was comprehensively evaluated by an expert group. To assess the patient’s postoperative quality of life, we administered the FACT-H & N (v 4.0) scale before and after surgery. Results: Among the 18 flaps, 10 were V-Y flaps and 8 were propeller flaps. The flaps of 18 patients survived, with adequate cheek, facial symmetry, and proper mouth opening. The flaps worked well and looked good at both the recipient and donor sites. According to the scale survey, the postoperative patients had a higher quality of life in terms of physiology, psychology, function, and other areas than the preoperative patients (P<0.05). Conclusion: A modified flap of the transverse facial artery can rotate flexibly and repair a larger area, as the blood flow is relatively constant near the zygomatic arch. It has a high clinical value in the treatment of zygomaticofacial tumors.