Study of spatial and temporal evolution of Ar and F atoms in SF6/Ar microsecond pulsed discharge by optical emission spectroscopy

The study of sulfur hexafluoride (SF₆) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge (PD) may cause SF₆ decomposition, and the decomposed products of SF₆, such as F atoms, play a dominant role in the breakdown of insulation systems. In this study, the PD caused by metal protrusion defects is simulated by a needle-plate electrode using pulsed high voltage in SF₆/Ar mixtures. The spatial and temporal characteristics of SF6/Ar plasma are analyzed by measuring the emission spectra of F and Ar atoms, which are important for understanding the characteristics of PD. The spatial resolved results show that both F and Ar atom spectral intensities increase first from the plate anode to the needle and then decrease under the conditions of a background pressure of 400 Pa, peak voltage of −1000 V, frequency of 2 kHz, pulse width of 60 μs, and electrode gap of 5–9 mm. However, the distribution characteristics of F and Ar are significantly different. The temporal distribution results show that the spectral intensity of Ar decreases first and then increases slowly, while the spectral intensity of F increases slowly for the duration of the pulsed discharge at the electrode gap of 5 mm and the pulse width of 40–80 μs.     

Quaternäre Metall/Metalloxid‐Katalysatoren als Wandkatalysatoren in Mikroreaktoren für Power‐to‐Gas‐Applikationen mittels kombinatorischer Hochdurchsatzmethoden

Catalysts of quaternary composition have been prepared and tested for the Sabatier process. For catalyst syntheses the following techniques have been used: sol‐gel methods, wet impregnation and incipient wetness impregnation. The Sabatier reaction was carried out at temperatures between 520 K and 670 K, pressures of 15 bar and 30 bar using a mixture H₂:CO₂ of 4:1. Activity screening of the microscale wall catalysts was performed by a custom‐built 10‐fold parallel gas‐flow microreactor setup in sequential operating mode. To analyze the gas phase compositions GC‐FID was used.     

Mechanical properties of continuous bamboo fiber-reinforced biobased polyamide 11 composites

This study is devoted to the analysis of the properties of continuous bamboo fiber (BF)-reinforced polyamide 11 (PA 11) composites. The SEM observations highlighted continuity between BFs and the polymeric matrix showing a high density of hydrogen bonds. The comparative calorimetric study of the matrix and its composites showed that the crystallinity of PA 11 was not modified by the presence of bamboo fibers. The physical aging observed in PA 11 is no more observed in composites due to physical interactions between PA 11 and BFs. The mechanical properties were investigated by tensile strength and dynamic mechanical analysis. The introduction of BFs enhanced Young's modulus of the matrix by a factor of 10. The presence of BFs also improved the storage shear modulus G′ over the whole temperature range. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47623.     

Catalytic performance of Cu- and Zr-modified beta zeolite catalysts in the methylation of 2-methylnaphthalene

2,6-Dimethylnaphthalene(2,6-DMN) is a commercially important chemical for the production of polyethylenenaphthalate and polybutylene naphthalate. However, its complex synthesis procedure and high production cost significantly reduce the use of 2,6-DMN. In this study, the synthesis of 2,6-DMN was investigated with methylation of 2-methylnaphthalene(2-MN) over metal-loaded beta zeolite catalysts including beta zeolite, Cu-impregnated beta zeolite and Zr-impregnated beta zeolite. The experiments were performed in a fixed-bed reactor at atmospheric pressure under a nitrogen atmosphere. The reactor was operated at a temperature range of 400–500 °C and varying weight hourly space velocity between 1 and 3 h~(-1).The results demonstrated that 2,6-DMN can be synthesized by methylation of 2-MN over beta type zeolite catalysts.Besides 2,6-DMN, the product stream also contained other DMN isomers such as 2,7-DMN, 1,3-DMN, 1,2-DMN and 2,3-DMN. The activity and selectivity of beta zeolite catalyst were remarkably enhanced by Zr impregnation, whereas Cu modification of beta zeolite catalyst had an insignificant effect on its selectivity. The highest conversion of 2-MN reached81%, the highest ratio of 2,6-DMN/2,7-DMN reached 2.6 and the highest selectivity of 2,6-DMN was found to be 20% by using Zr-modified beta zeolite catalyst.     

基于“IPv6+”的智能IP网络方案

随着第4次工业革命的到来，人类社会正逐步迈向万物互联的智能时代。智能时代需要更加自动化、智能化的IP网络，基于“IPv6+”的SRv6、BIERv6等技术是使能新一代IP网络的关键基础。全面阐述了“IPv6+”的技术内涵，结合华为在智能 IP 网络解决方案上的创新和思考，介绍了“IPv6+”在极简连接、SLA 保障、专网体验、质量感知和云网一体等多个解决方案场景的关键技术与典型应用，助力5G与云业务发展。     

Tumor Necrosis Factor α and Interleukin-1β Acutely Inhibit AgRP Neurons in the Arcuate Nucleus of the Hypothalamus

Obesity-associated low-grade inflammation favors weight gain, whereas systemic infection frequently leads to anorexia. Thus, inflammatory signals can either induce positive or negative energy balance. In this study, we used whole-cell patch-clamp to investigate the acute effects of three important proinflammatory cytokines, tumor necrosis factor α (TNF-α), interleukin-6, and interleukin-1β (IL-1β) on the membrane excitability of agouti-related peptide (AgRP)- or proopiomelanocortin (POMC)-producing neurons. We found that both TNF-α and IL-1β acutely inhibited the activity of 35–42% of AgRP-producing neurons, whereas very few POMC neurons were depolarized by TNF-α. Interleukin-6 induced no acute changes in the activity of AgRP or POMC neurons. Our findings indicate that the effect of TNF-α and IL-1β, especially on the activity of AgRP-producing neurons, may contribute to inflammation-induced anorexia observed during acute inflammatory conditions.     

CYP2D6基因多态性对托烷司琼预防化疗所致恶心呕吐效果的影响

肿瘤对人类健康造成很大威胁。化疗作为一种全身性的治疗方法，在肿瘤治疗中的地位不可动摇。化疗所致恶心呕吐（chemotherapy induced nausea and vomiting, CINV）是化疗过程中常见的不良反应，严重影响了患者的情绪、生活质量和肿瘤的控制。CINV的防治对肿瘤患者来说非常重要。托烷司琼是较常用的5-羟色胺Ⅲ亚型（5-hydroxytryptamine type 3, 5-HT3）受体拮抗剂，在防治CINV方面具有很好的临床效果，但仍有部分患者使用托烷司琼后效果不佳。越来越多的研究表明这些个体差异可能与基因多态性密切相关。本文就细胞色素P450 2D6（cytochrome P450 2D6, CYP2D6）基因多态性对托烷司琼预防CINV效果的影响作一综述，以期为基因多态性指导下的临床个体化用药提供思路。     

综放工作面风量及采空区漏风定量检测

通过对中煤塔山煤矿30509综放工作面采空区漏风及有害气体分析的研究，总结了通过定量连续释放SF₆示踪气体，来检测工作面风量与采空区漏风的方法，测定了沿工作面采空区的漏风分布及漏风流线的深度。采用定时测量法，确定了30509工作面随工作面不断推进，与对应地表发生了导通现象；采用定量测量法，确定了内部漏风量和外部漏风量较大，对综采工作面采空区自然发火存在较大风险，同时提出了防范措施，为减少综放工作面采空区漏风、防止自然发火的发生提供了参考。     

A Potent Mimetic of the Siglec-8 Ligand 6’-Sulfo-Sialyl Lewisx

Siglecs are members of the immunoglobulin gene family containing sialic acid binding N-terminal domains. Among them, Siglec-8 is expressed on various cell types of the immune system such as eosinophils, mast cells and weakly on basophils. Cross-linking of Siglec-8 with monoclonal antibodies triggers apoptosis in eosinophils and inhibits degranulation of mast cells, making Siglec-8 a promising target for the treatment of eosinophil- and mast cell-associated diseases such as asthma. The tetrasaccharide 6’-sulfo-sialyl Lewis^x has been identified as a specific Siglec-8 ligand in glycan array screening. Here, we describe an extended study enlightening the pharmacophores of 6’-sulfo-sialyl Lewis^x and the successful development of a high-affinity mimetic. Retaining the neuraminic acid core, the introduction of a carbocyclic mimetic of the Gal moiety and a sulfonamide substituent in the 9-position gave a 20-fold improved binding affinity. Finally, the residence time, which usually is the Achilles tendon of carbohydrate/lectin interactions, could be improved.     

Future changes in wind energy resource over the Northwest Passage based on the CMIP6 climate projections

The preferential use of renewable energy sources such as wind power has been proposed as one of the most effective strategies in reducing greenhouse gas emissions in the energy sector. However, wind energy resources are vulnerable to climate change, which might have a huge impact on the area under consideration. In this research, we used the wind speed data obtained from the seven coupled global climate models in the Coupled Model Intercomparison Project Phase 6 (CMIP6) to quantitatively analyze the differences in wind energy resource (WER) between the future and the historical period, geared toward understanding the impact of climate change on wind energy sources. Relevant results show that the future WER would decreases below 20% in the region south of the Northwest Passage, while would significantly increase in the north region of 72°N (specifically in the Beaufort Sea). Further, reports predict that by the end of the 21st century, if no interventions are made to mitigate greenhouse gas emissions, the northern region's WER would increase even more with some grid points exceeding 30% and have a significant growth trend, but at the same time the intra‐annual variability in these region would also increase significantly with some grid points exceeding 140% of that in the historical period. Moreover, the maximum wind speed values would encounter a noteworthy increase of up to 20%, which will bring great challenge to the development of wind energy in these region. Although the current models still have great uncertainties in the future climate prediction, our work still has certain guiding significance for the future development of wind energy over the Northwest Passage.