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1.
Foods ; 12(13)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37444210

RESUMO

This two-consecutive-year study aimed to evaluate the effects of ground management methods on the volatomics of 'Cabernet Sauvignon' grapes and wines in Northwest China, in which inner-row crop covering with purslane (GRASS) and mulching with black plastic film (FILM) treatments were carried out, respectively. Compared with clean tillage (CK), the GRASS and FILM treatments changed the microclimates of grapevine fruit zones and rhizospheres, which delayed the ripening of grape berries and affected the accumulation of aroma substances in the mature grapes effectively. GRASS increased the concentration of terpenes and C13-norisoprenoids in berries and gave more floral, fruity, and caramel fragrances to wines, while FILM had the opposite effect of significantly increasing the synthesis of C6/C9 compounds and brought more green leaf flavors, showing that inner-row purslane covering is a potential and stable viticultural practice to improve the wine quality in this booming wine region.

2.
J Biomed Mater Res B Appl Biomater ; 109(6): 808-817, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33118325

RESUMO

In this study, we have innovatively proposed a method for surface modification of ultra-high molecular weight polyethylene (UHMWPE) artificial joint materials with graphene oxide (GO) infiltrated into UHMWPE substrate by ultrasonic induction. The mechanical properties of UHMWPE nanocomposites with GO infiltrated by ultrasonic induction were compared with that of GO mixed. The molecular structure, wettability, peak load, and bio-tribological behavior of GO/UHMWPE nanocomposites were studied using fourier transform infrared spectroscopy, contact angle measuring instrument, electronic universal material testing machine, tribometer, and profilometer, respectively. The results show that the ultrasonic-induction method can make GO adhere to UHMWPE surface well, and GO can significantly improve the wettability of UHMWPE substrate. When the ultrasound-inducted time is up to 12 hr, the wetting angle of the nanocomposites (12 h-GO/UHMWPE) is reduced to 65.24°, which is 20.51% lower than that of the pure UHMWPE. The peak load is 183 N, which is 20.22% higher than that of GO/UHMWPE prepared by the mixing method. The bio-tribological property of UHMWPE nanocomposites with GO infiltrated by ultrasonic induction for 12 hr (12 h-GO/UHMWPE) is the best, and its friction coefficient keeps more stable at a value of 0.0605 under the lubrication of calf serum, which is 11.81% lower than that of UHMWPE mixed with GO by a traditional method, and the wear rate is decreased to 3.25 × 10-5 mm3 N-1 m-1 .


Assuntos
Grafite/química , Teste de Materiais , Nanocompostos/química , Polietilenos/química , Ondas Ultrassônicas , Propriedades de Superfície
3.
Materials (Basel) ; 13(4)2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32093179

RESUMO

A model with an inner structure was designed to study the relationship between the surface quality of the inner structure and the scan strategy in this study. The test results showed that the precision of the inner structure was highly affected by the scan strategy, and the specimens printed using different strategies showed different performances on the surface quality of the inner structure. The specimen printed using the square-framed scan strategy had a lower flatness value on the positive face of the inner structure compared to that of the other two specimens printed using Z-shape scan strategies, while the specimen printed using the Z-shape scan strategy (along the inner structure) had a relative optimal surface roughness on the side surface of the inner structure in all three specimens. The bending deformation caused by the scan strategies was considered to be the main factor affecting the flatness on the positive surface, while laser energy fluctuation showed a significant impact on side surface roughness. Combined with the experimental data, a new scan strategy was proposed; we found that the specimen printed using this new strategy improved positive surface flatness and side surface roughness.

4.
RSC Adv ; 10(8): 4175-4188, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35495271

RESUMO

Recently, there has been increasing interest in modifying ultra-high molecular weight polyethylene (UHMWPE) due to glaring needs in the artificial joint replacement field. It is generally reported in the literature that irradiation cross-linking and adding graphene oxide (GO)/vitamin E (VE) can enhance the mechanical properties of UHMWPE, but this can sacrifice the oxidation stability and gel content. This paper examines how VE diffusion can influence irradiation cross-linked GO/UHMWPE composites and whether mechanical performance and oxidation resistance can be maintained simultaneously, which will provide new guidance for prolonging the longevity of UHMWPE implants. The GO/UHMWPE composites were fabricated by means of liquid ultrasonic dispersion, hot pressing and irradiation cross-linking, followed by VE diffusion and homogenization treatment. The results indicated that limited VE diffusion decreased the water absorption and wettability. The crystallinity, melting temperature, thermal stability, hardness and scratch resistance of the composites basically remain essentially the same, except in the case of pure UHMWPE. In addition, the oxidation resistance was improved significantly after incorporating VE. Furthermore, the diffusion and enhancement mechanisms were also demonstrated, respectively.

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