5G时代的切片技术浅析

5G时代的通信场景将更加多元化,更加丰富多彩,5G网络的切片正是实现多元化的关键技术。本文首先介绍了切片的概念和特点,然后探讨了切片的分类、部署方式、全生命周期管理,最后对切片的技术基础、后续需研究的技术重点进行了分析阐述。     

The aggregation behavior and structure of blends of κ-carrageenan and ε-polylysine hydrochloride

Polypeptides play a key role in improving food quality, and understanding their interactions with polysaccharides would be beneficial to developing new foods. Herein, κ-carrageenan (KC) and ε-polylysine hydrochloride (PLH) were chosen as the model polysaccharide and polypeptide, respectively, to study polysaccharide/polypeptide complexes. The KC/PLH solutions were characterized for turbidity as a function of mass ratio, pH, salts and stirred conditions at 0.5 and 1 mg mL^–1 concentrations. The solutions at a KC/PLH mass ratio of 7:3 have the highest turbidity, and the turbidity is stable in acidic conditions, decreases with increase in pH in alkaline conditions and salt concentration, and increases with increase of stirred time and temperature. The Fourier transform infrared spectra suggest that the amide I band of PLH disappears along with a change in the amide II band upon complexing with KC. These changes further influence the microstructure and reveal a rough, non-uniform and large irregular cavity network structure. Indeed, these observations are intimately associated with the dynamic interactions persistent at the molecular level between the KC and PLH. © 2021 Society of Industrial Chemistry.     

Thermodynamics-antioxidant activity relationships of some 4-benzylidenamino-4, 5-dihydro-1h-1,2,4-triazol-5-one derivatives: Theoretical evaluation

Density functional methods were used to predict the antioxidative efficiency of thirteen 4-benzylidenamino-4, 5-dihydro-1H-1,2,4-triazol-5-one derivatives in the gas phase and in the solution phase (water and benzene). Optimized geometries of molecules and reaction thermodynamic energies (enthalpies and reaction-free energies) of three main antioxidant mechanisms (hydrogen atom transfer, single electron transfer-proton transfer, and sequential proton loss electron transfer) were studied at B3LYP/6-31G (d,p) level. Solvent contributions to thermodynamic energies were computed employing integral equation formalism integral equation formalism polarized continuum model method. Obtained results revealed that the three main working mechanisms were endothermic, but not spontaneous especially in the gas phase. We found that the single electron transfer process from the anionic form was more preferable than that from the neutral form in the gas phase. The comparison of the ionization potentials of 4-benzylidenamino-4, 5-dihydro-1H-1,2,4-triazol-5-one derivatives to those of classical antioxidants (gallic acid, caffeic acid, ferulic acid, and ascorbic acid) indicated that the electron transfer mechanism was more predominant in the thirteen 4-benzylidenamino-4, 5-dihydro-1H-1,2,4-triazol-5-one derivative compounds. Thermodynamically, single electron transfer process from the anionic form was the most preferable mechanism in the gas phase. Solvent effect drastically modified thermodynamic energies of mechanisms. The proton transfer process was the thermodynamically favored mechanism as compared to other mechanisms in both solvents. It is worth mentioning that all the mechanisms were found not to be spontaneous in the solution phase except the proton transfer process.     

Kinetic Modeling of the Gas Antisolvent Process for Synthesis of 5‐Fluorouracil Nanoparticles

Mathematical modeling for 5‐fluorouracil (5‐FU) nanoparticle synthesis via gas antisolvent (GAS) process was investigated. 5‐FU was precipitated from a dimethyl sulfoxide (DMSO) solution using CO₂ as antisolvent. The particle size was controlled by nucleation and growth rates, therefore, the kinetic modeling study is essential. Thermodynamic modeling was applied to determine optimal operating conditions for experimental 5‐FU synthesis. Kinetic parameters were evaluated by fitting the particle size distribution predicted by the model to experimental data. The experimental and modeling results indicated that the particle size decreased with increasing the antisolvent addition rate.     

Effects of annealing time on microstructure and mechanical properties of MosSi3 alloy

以纯金属Mo和纯Si为原料，采用电弧熔炼法制备了Mo5Si3合金。在1200℃对其进行不同时间真空退火，并对合金的相组成、显微结构及力学性能进行分析。结果表明，随退火时间的延长，合金致密度、显微硬度和抗压强度提高，其压痕断裂韧性表现出先增加后降低的趋势，退火20h后合金断裂韧性为3．23MPa·m^1/2。退火50h后，合金主要物相为Mo5Si3和少量MoSi2，在合金中形成M05Si3／MoSi2层片状组织结构，层片间距在20-50μm之间。M05Si3晶粒尺寸和点阵畸变分别为87．3nm和0．0986％，合金具有纳米晶结构。     

Effects of plasma treatment on biocompatibility of poly[(L‐lactide)‐co‐(ϵ‐caprolactone)] and poly[(L‐lactide)‐co‐glycolide] electrospun nanofibrous membranes

Poly[(l ‐lactide)‐co ‐(? ‐caprolactone)] (PLCL) and poly[(l ‐lactide)‐co ‐glycolide] (PLGA) copolymers are widely used in neural guide tissue regeneration. In this research, the surface modification of their hydrophilicity was achieved using plasma treatment. Attachment and proliferation of olfactory ensheathing cells on treated electrospun membranes increased by 26 and 32%, respectively, compared to the untreated PLCL and PLGA counterparts. Cells cultivated on both the PLCL and PLGA membranes showed high viability (>95%) and healthy morphologies with no evidence of cytotoxic effects. Cells grown on treated electrospun fibres displayed significant increases in mitochondrial activity and reductions in membrane leakage when compared to untreated samples. The results suggested that plasma treatment of the surface of the polymers enhanced both cell viability and growth without incurring any cytotoxic effects. © 2017 Society of Chemical Industry     

Workspace and statics analysis of 4-UPS-UPU parallel coordinate measuring machine

A novel 4-UPS-UPU spatial 5-Degree of freedom parallel coordinate measuring machine (PCMM) is presented. The workspace of the measuring machine is analyzed by using polar coordinate searching method. The force balance equation and statics transfer matrix of the measuring machine are established. The statics analysis of the 4-UPS-UPU PCMM is realized by taking the PCMM with load and no-load as example, and the numerical verification and virtual simulation verification of the results of driving force are carried out. The research can provide a theoretical basis for the optimal design and manufacturing of 4-UPS-UPU PCMM.     

Effect of brewing process and sugar content on 5-hydroxymethylfurfural and related substances from Turkish coffee

The effect of brewing process on 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid levels of traditionally prepared and instant Turkish coffee samples containing different amounts of table sugar (0, 2, 4, or 8 g in 20 mL of coffee) were analyzed by high pressure liquid chromatography with diode array detector. The highest change at the levels of furfurals was observed in sample of traditional and instant Turkish coffee named T4 and S4 both of containing 8 g of sugar, respectively. The results showed that 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid concentrations in both traditionally prepared and instant Turkish coffee samples increased with increasing sugar concentration. The brewing method and sugar concentration had a significant effect on furfural contents of Turkish coffee (p < 0.05). Daily intakes of furfurals for Turkish population were calculated as 8.14–13.54 and 9.36–10.25 µg kg^?1 body weight for traditionally prepared and instant Turkish coffee samples, respectively, and daily intakes of furfurals were lower than the acceptable daily intake value of 0.5 mg kg^?1 body weight.     

Influence of snow shovel shaft configuration on lumbosacral biomechanics during a load-lifting task

Lower-back injury from snow shovelling may be related to excessive joint loading. Bent-shaft snow shovels are commonly available for purchase; however, their influence on lower back-joint loading is currently not known. Therefore, the purpose of this study was to compare L5/S1 extension angular impulses between a bent-shaft and a standard straight-shaft snow shovel. Eight healthy subjects participated in this study. Each completed a simulated snow-lifting task in a biomechanics laboratory with each shovel design. A standard motion analysis procedure was used to determine L5/S1 angular impulses during each trial, as well as peak L5/S1 extension moments and peak upper body flexion angle. Paired-samples t-tests (α = 0.05) were used to compare variables between shovel designs. Correlation was used to determine the relationship between peak flexion and peak moments. Results of this study show that the bent-shaft snow shovel reduced L5/S1 extension angular impulses by 16.5% (p = 0.022), decreased peak moments by 11.8% (p = 0.044), and peak flexion by 13.0% (p = 0.002) compared to the straight-shaft shovel. Peak L5/S1 extension moment magnitude was correlated with peak upper body flexion angle (r = 0.70). Based on these results, it is concluded that the bent-shaft snow shovel can likely reduce lower-back joint loading during snow shovelling, and thus may have a role in snow shovelling injury prevention.