A promising approach to enhance catalytic performance of supported heterogeneous nano-metal catalysts is to uniformly disperse active nanoparticles on the support. In this work, N-doped carbon-modified graphene (G@NC) nanosheet is designed and prepared to anchor Pd–Fe bimetallic nanoparticles (Pd–Fe/G@NC). The N-doped carbon modification on graphene surface could construct a sandwich-like structure (G@NC), which not only prevented the re-stacking of graphene nanosheets but also provided confined space for stable anchoring of bimetallic Pd–Fe nanoparticles. Benefitted from the unique structural property and synergetic effect of metal Pd and Fe species, the as-obtained Pd–Fe/G@NC composite displays excellent catalytic activity toward 4-nitrophenol reduction reaction with a turnover frequency of 613.2 min− 1, which is far superior to that of the mono-metal counterparts (Fe/G@NC and Pd/G@NC). More importantly, Pd–Fe/G@NC catalyst also exhibits favorable catalytic performance in the reduction of other nitroaromatic compounds (nitrobenzene, 4-nitrotoluene, 4-chloronitrobenzene, and so on). In addition, Pd–Fe/G@NC can catalyze the oxidation of furfuraldehyde to furoic acid with a high yield of 88.64%. This work provides a new guide for rationally designing and developing advanced supported heterogeneous bimetallic catalyst.

VR 수술 시스템의 도입은 현대 의학 교육에 큰 의미가 있다. VR 수술 시스템은 의대생과 젊은 의사의 학습 효율을 크게 향상시키고 반복 훈련 목표를 달성하며 전통 의학 교육의 단점을 보완할 수 있다. 사회적 디지 털화가 심화됨에 따라 의료 분야의 VR 수술 시스템 구축이 시급해지고 있다. 본 논문은 의료에 적용되는 기능성 게임의 관점에서 VR 수술의 기능성게임 디자인을 연구한다. 먼저 사용자 경험 이론과 사용자 심리적 필요사항을 바탕으로 기능성 게임에 대한 사용자 경험과 기대치를 분석하였다. 그리고 사용자의 실제 필요사항과 게임 레벨 기능 디자인을 분석하고, 게임 디자인의 핵심 포인트를 강조하여 최적화하였다. 둘째, 3D MAX를 결합한 UE4 모델 구성의 주의할 점을 분석하였다. 마지막으로 위 연구를 바탕으로 흉강경 하에서 폐기포 VR 수술의 본격적인 게임을 설계하였다. 게임 디자인은 대상 사용자를 분석하여 내용을 결정한 후 이를 전문의에게 확인하여 이루어졌다. 첫째, 인간 가슴의 얇은 CT 이미지를 기반으로 3DS MAX를 이용 하여 가슴 모델, 수술 도구 및 수술 장면을 시뮬레이션 하였다. 둘째, UE4 게임 엔진을 사용하였다. 이 기술 은 3D 모델이 기능성 게임 시뮬레이션의 요구 사항을 충족하도록 만들고 UE4 장면을 디자인하며 C ++ 언 어를 사용하여 게임 기능을 개발하였다.

Conductive and dielectric SiC are fabricated using electroless plating of Ni–Fe films on SiC chopped fibers to obtain lightweight and high-strength microwave absorbers. The electroless plating of Ni–Fe films is achieved using a two-step process of surface sensitizing and metal plating. The complex permeability and permittivity are measured for the composite specimens with the metalized SiC chopped fibers dispersed in a silicone rubber matrix. The original noncoated SiC fibers exhibit considerable dielectric losses. The complex permeability spectrum does not change significantly with the Ni–Fe coating. Moreover, dielectric constant is sensitively increased with Ni–Fe coating, owing to the increase of the space charge polarization. The improvements in absorption capability (lower reflection loss and small matching thickness) are evident with Ni–Fe coating on SiC fibers. For the composite SiC fibers coated with Ni–Fe thin films, a -35 dB reflection loss is predicted at 7.6 GHz with a matching thickness of 4 mm.

This study was conducted to develop a model for describing the effect of storage temperature (4, 10, 15, 20, 25, 30 and 35℃) on the growth of Escherichia coli O157 : H7 in ready-to-eat (RTE) lettuce treated with or without (control) alkaline electrolyzed water (AIEW). The growth curves were well fitted with the Gompertz equation, which was used to determine the specific growth rate (SGR) and lag time (LT) of E. coli O157 : H7 (R2 = 0.994). Results showed that the obtained SGR and LT were dependent on the storage temperature. The growth rate increased with increasing temperature from 4 to 35℃. The square root models were used to evaluate the effect of storage temperature on the growth of E. coli O157 : H7 in lettuce samples treated without or with AIEW. The coefficient of determination (R2), adjusted determination coefficient (R2 Adj), and mean square error (MSE) were employed to validate the established models. It showed that R2 and R2 Adj were close to 1 (> 0.93), and MSE calculated from models of untreated and treated lettuce were 0.031 and 0.025, respectively. The results demonstrated that the overall predictions of the growth of E. coli O157 : H7 agreed with the observed data.